Add the clang library to the repo (with some of my changes, too).

26 files changed, 10855 insertions, 0 deletions

diff --git a/clang/lib/Analysis/.#CMakeLists.txt b/clang/lib/Analysis/.#CMakeLists.txt
new file mode 120000
index 0000000..235903b
--- /dev/null
+++ b/clang/lib/Analysis/.#CMakeLists.txt
@@ -0,0 +1 @@
+carlo@pc-4w14-0.cs.usyd.edu.au.1585:1347012043
\ No newline at end of file
diff --git a/clang/lib/Analysis/.#Interval.cpp b/clang/lib/Analysis/.#Interval.cpp
new file mode 120000
index 0000000..235903b
--- /dev/null
+++ b/clang/lib/Analysis/.#Interval.cpp
@@ -0,0 +1 @@
+carlo@pc-4w14-0.cs.usyd.edu.au.1585:1347012043
\ No newline at end of file
diff --git a/clang/lib/Analysis/.#Interval_flymake.cpp b/clang/lib/Analysis/.#Interval_flymake.cpp
new file mode 120000
index 0000000..235903b
--- /dev/null
+++ b/clang/lib/Analysis/.#Interval_flymake.cpp
@@ -0,0 +1 @@
+carlo@pc-4w14-0.cs.usyd.edu.au.1585:1347012043
\ No newline at end of file
diff --git a/clang/lib/Analysis/.#LiveVariables.cpp b/clang/lib/Analysis/.#LiveVariables.cpp
new file mode 120000
index 0000000..235903b
--- /dev/null
+++ b/clang/lib/Analysis/.#LiveVariables.cpp
@@ -0,0 +1 @@
+carlo@pc-4w14-0.cs.usyd.edu.au.1585:1347012043
\ No newline at end of file
diff --git a/clang/lib/Analysis/.#LiveVariables_flymake.cpp b/clang/lib/Analysis/.#LiveVariables_flymake.cpp
new file mode 120000
index 0000000..235903b
--- /dev/null
+++ b/clang/lib/Analysis/.#LiveVariables_flymake.cpp
@@ -0,0 +1 @@
+carlo@pc-4w14-0.cs.usyd.edu.au.1585:1347012043
\ No newline at end of file
diff --git a/clang/lib/Analysis/AnalysisDeclContext.cpp b/clang/lib/Analysis/AnalysisDeclContext.cpp
new file mode 100644
index 0000000..659cc6d
--- /dev/null
+++ b/clang/lib/Analysis/AnalysisDeclContext.cpp
@@ -0,0 +1,463 @@
+//== AnalysisDeclContext.cpp - Analysis context for Path Sens analysis -*- C++ -*-//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines AnalysisDeclContext, a class that manages the analysis context
+// data for path sensitive analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/ParentMap.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Analysis/Analyses/LiveVariables.h"
+#include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
+#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/CFGStmtMap.h"
+#include "clang/Analysis/Support/BumpVector.h"
+#include "llvm/Support/SaveAndRestore.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace clang;
+
+typedef llvm::DenseMap<const void *, ManagedAnalysis *> ManagedAnalysisMap;
+
+AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
+                                 const Decl *d,
+                                 idx::TranslationUnit *tu,
+                                 const CFG::BuildOptions &buildOptions)
+  : Manager(Mgr),
+    D(d),
+    TU(tu),
+    cfgBuildOptions(buildOptions),
+    forcedBlkExprs(0),
+    builtCFG(false),
+    builtCompleteCFG(false),
+    ReferencedBlockVars(0),
+    ManagedAnalyses(0)
+{  
+  cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
+}
+
+AnalysisDeclContext::AnalysisDeclContext(AnalysisDeclContextManager *Mgr,
+                                 const Decl *d,
+                                 idx::TranslationUnit *tu)
+: Manager(Mgr),
+  D(d),
+  TU(tu),
+  forcedBlkExprs(0),
+  builtCFG(false),
+  builtCompleteCFG(false),
+  ReferencedBlockVars(0),
+  ManagedAnalyses(0)
+{  
+  cfgBuildOptions.forcedBlkExprs = &forcedBlkExprs;
+}
+
+AnalysisDeclContextManager::AnalysisDeclContextManager(bool useUnoptimizedCFG,
+                                               bool addImplicitDtors,
+                                               bool addInitializers) {
+  cfgBuildOptions.PruneTriviallyFalseEdges = !useUnoptimizedCFG;
+  cfgBuildOptions.AddImplicitDtors = addImplicitDtors;
+  cfgBuildOptions.AddInitializers = addInitializers;
+}
+
+void AnalysisDeclContextManager::clear() {
+  for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
+    delete I->second;
+  Contexts.clear();
+}
+
+Stmt *AnalysisDeclContext::getBody() const {
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+    return FD->getBody();
+  else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
+    return MD->getBody();
+  else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D))
+    return BD->getBody();
+  else if (const FunctionTemplateDecl *FunTmpl
+           = dyn_cast_or_null<FunctionTemplateDecl>(D))
+    return FunTmpl->getTemplatedDecl()->getBody();
+
+  llvm_unreachable("unknown code decl");
+}
+
+const ImplicitParamDecl *AnalysisDeclContext::getSelfDecl() const {
+  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
+    return MD->getSelfDecl();
+  if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
+    // See if 'self' was captured by the block.
+    for (BlockDecl::capture_const_iterator it = BD->capture_begin(),
+         et = BD->capture_end(); it != et; ++it) {
+      const VarDecl *VD = it->getVariable();
+      if (VD->getName() == "self")
+        return dyn_cast<ImplicitParamDecl>(VD);
+    }    
+  }
+
+  return NULL;
+}
+
+void AnalysisDeclContext::registerForcedBlockExpression(const Stmt *stmt) {
+  if (!forcedBlkExprs)
+    forcedBlkExprs = new CFG::BuildOptions::ForcedBlkExprs();
+  // Default construct an entry for 'stmt'.
+  if (const Expr *e = dyn_cast<Expr>(stmt))
+    stmt = e->IgnoreParens();
+  (void) (*forcedBlkExprs)[stmt];
+}
+
+const CFGBlock *
+AnalysisDeclContext::getBlockForRegisteredExpression(const Stmt *stmt) {
+  assert(forcedBlkExprs);
+  if (const Expr *e = dyn_cast<Expr>(stmt))
+    stmt = e->IgnoreParens();
+  CFG::BuildOptions::ForcedBlkExprs::const_iterator itr = 
+    forcedBlkExprs->find(stmt);
+  assert(itr != forcedBlkExprs->end());
+  return itr->second;
+}
+
+CFG *AnalysisDeclContext::getCFG() {
+  if (!cfgBuildOptions.PruneTriviallyFalseEdges)
+    return getUnoptimizedCFG();
+
+  if (!builtCFG) {
+    cfg.reset(CFG::buildCFG(D, getBody(),
+                            &D->getASTContext(), cfgBuildOptions));
+    // Even when the cfg is not successfully built, we don't
+    // want to try building it again.
+    builtCFG = true;
+  }
+  return cfg.get();
+}
+
+CFG *AnalysisDeclContext::getUnoptimizedCFG() {
+  if (!builtCompleteCFG) {
+    SaveAndRestore<bool> NotPrune(cfgBuildOptions.PruneTriviallyFalseEdges,
+                                  false);
+    completeCFG.reset(CFG::buildCFG(D, getBody(), &D->getASTContext(),
+                                    cfgBuildOptions));
+    // Even when the cfg is not successfully built, we don't
+    // want to try building it again.
+    builtCompleteCFG = true;
+  }
+  return completeCFG.get();
+}
+
+CFGStmtMap *AnalysisDeclContext::getCFGStmtMap() {
+  if (cfgStmtMap)
+    return cfgStmtMap.get();
+  
+  if (CFG *c = getCFG()) {
+    cfgStmtMap.reset(CFGStmtMap::Build(c, &getParentMap()));
+    return cfgStmtMap.get();
+  }
+    
+  return 0;
+}
+
+CFGReverseBlockReachabilityAnalysis *AnalysisDeclContext::getCFGReachablityAnalysis() {
+  if (CFA)
+    return CFA.get();
+  
+  if (CFG *c = getCFG()) {
+    CFA.reset(new CFGReverseBlockReachabilityAnalysis(*c));
+    return CFA.get();
+  }
+  
+  return 0;
+}
+
+void AnalysisDeclContext::dumpCFG(bool ShowColors) {
+    getCFG()->dump(getASTContext().getLangOpts(), ShowColors);
+}
+
+ParentMap &AnalysisDeclContext::getParentMap() {
+  if (!PM)
+    PM.reset(new ParentMap(getBody()));
+  return *PM;
+}
+
+PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
+  if (!PCA)
+    PCA.reset(new PseudoConstantAnalysis(getBody()));
+  return PCA.get();
+}
+
+AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D,
+                                                    idx::TranslationUnit *TU) {
+  AnalysisDeclContext *&AC = Contexts[D];
+  if (!AC)
+    AC = new AnalysisDeclContext(this, D, TU, cfgBuildOptions);
+  return AC;
+}
+
+const StackFrameContext *
+AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
+                               const CFGBlock *Blk, unsigned Idx) {
+  return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
+}
+
+LocationContextManager & AnalysisDeclContext::getLocationContextManager() {
+  assert(Manager &&
+         "Cannot create LocationContexts without an AnalysisDeclContextManager!");
+  return Manager->getLocationContextManager();  
+}
+
+//===----------------------------------------------------------------------===//
+// FoldingSet profiling.
+//===----------------------------------------------------------------------===//
+
+void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
+                                    ContextKind ck,
+                                    AnalysisDeclContext *ctx,
+                                    const LocationContext *parent,
+                                    const void *data) {
+  ID.AddInteger(ck);
+  ID.AddPointer(ctx);
+  ID.AddPointer(parent);
+  ID.AddPointer(data);
+}
+
+void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
+  Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block, Index);
+}
+
+void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
+  Profile(ID, getAnalysisDeclContext(), getParent(), Enter);
+}
+
+void BlockInvocationContext::Profile(llvm::FoldingSetNodeID &ID) {
+  Profile(ID, getAnalysisDeclContext(), getParent(), BD);
+}
+
+//===----------------------------------------------------------------------===//
+// LocationContext creation.
+//===----------------------------------------------------------------------===//
+
+template <typename LOC, typename DATA>
+const LOC*
+LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
+                                           const LocationContext *parent,
+                                           const DATA *d) {
+  llvm::FoldingSetNodeID ID;
+  LOC::Profile(ID, ctx, parent, d);
+  void *InsertPos;
+
+  LOC *L = cast_or_null<LOC>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
+
+  if (!L) {
+    L = new LOC(ctx, parent, d);
+    Contexts.InsertNode(L, InsertPos);
+  }
+  return L;
+}
+
+const StackFrameContext*
+LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
+                                      const LocationContext *parent,
+                                      const Stmt *s,
+                                      const CFGBlock *blk, unsigned idx) {
+  llvm::FoldingSetNodeID ID;
+  StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
+  void *InsertPos;
+  StackFrameContext *L =
+   cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
+  if (!L) {
+    L = new StackFrameContext(ctx, parent, s, blk, idx);
+    Contexts.InsertNode(L, InsertPos);
+  }
+  return L;
+}
+
+const ScopeContext *
+LocationContextManager::getScope(AnalysisDeclContext *ctx,
+                                 const LocationContext *parent,
+                                 const Stmt *s) {
+  return getLocationContext<ScopeContext, Stmt>(ctx, parent, s);
+}
+
+//===----------------------------------------------------------------------===//
+// LocationContext methods.
+//===----------------------------------------------------------------------===//
+
+const StackFrameContext *LocationContext::getCurrentStackFrame() const {
+  const LocationContext *LC = this;
+  while (LC) {
+    if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC))
+      return SFC;
+    LC = LC->getParent();
+  }
+  return NULL;
+}
+
+const StackFrameContext *
+LocationContext::getStackFrameForDeclContext(const DeclContext *DC) const {
+  const LocationContext *LC = this;
+  while (LC) {
+    if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
+      if (cast<DeclContext>(SFC->getDecl()) == DC)
+        return SFC;
+    }
+    LC = LC->getParent();
+  }
+  return NULL;
+}
+
+bool LocationContext::isParentOf(const LocationContext *LC) const {
+  do {
+    const LocationContext *Parent = LC->getParent();
+    if (Parent == this)
+      return true;
+    else
+      LC = Parent;
+  } while (LC);
+
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// Lazily generated map to query the external variables referenced by a Block.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class FindBlockDeclRefExprsVals : public StmtVisitor<FindBlockDeclRefExprsVals>{
+  BumpVector<const VarDecl*> &BEVals;
+  BumpVectorContext &BC;
+  llvm::SmallPtrSet<const VarDecl*, 4> Visited;
+  llvm::SmallPtrSet<const DeclContext*, 4> IgnoredContexts;
+public:
+  FindBlockDeclRefExprsVals(BumpVector<const VarDecl*> &bevals,
+                            BumpVectorContext &bc)
+  : BEVals(bevals), BC(bc) {}
+
+  bool IsTrackedDecl(const VarDecl *VD) {
+    const DeclContext *DC = VD->getDeclContext();
+    return IgnoredContexts.count(DC) == 0;
+  }
+
+  void VisitStmt(Stmt *S) {
+    for (Stmt::child_range I = S->children(); I; ++I)
+      if (Stmt *child = *I)
+        Visit(child);
+  }
+
+  void VisitDeclRefExpr(DeclRefExpr *DR) {
+    // Non-local variables are also directly modified.
+    if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+      if (!VD->hasLocalStorage()) {
+        if (Visited.insert(VD))
+          BEVals.push_back(VD, BC);
+      } else if (DR->refersToEnclosingLocal()) {
+        if (Visited.insert(VD) && IsTrackedDecl(VD))
+          BEVals.push_back(VD, BC);
+      }
+    }
+  }
+
+  void VisitBlockExpr(BlockExpr *BR) {
+    // Blocks containing blocks can transitively capture more variables.
+    IgnoredContexts.insert(BR->getBlockDecl());
+    Visit(BR->getBlockDecl()->getBody());
+  }
+  
+  void VisitPseudoObjectExpr(PseudoObjectExpr *PE) {
+    for (PseudoObjectExpr::semantics_iterator it = PE->semantics_begin(), 
+         et = PE->semantics_end(); it != et; ++it) {
+      Expr *Semantic = *it;
+      if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
+        Semantic = OVE->getSourceExpr();
+      Visit(Semantic);
+    }
+  }
+};
+} // end anonymous namespace
+
+typedef BumpVector<const VarDecl*> DeclVec;
+
+static DeclVec* LazyInitializeReferencedDecls(const BlockDecl *BD,
+                                              void *&Vec,
+                                              llvm::BumpPtrAllocator &A) {
+  if (Vec)
+    return (DeclVec*) Vec;
+
+  BumpVectorContext BC(A);
+  DeclVec *BV = (DeclVec*) A.Allocate<DeclVec>();
+  new (BV) DeclVec(BC, 10);
+
+  // Find the referenced variables.
+  FindBlockDeclRefExprsVals F(*BV, BC);
+  F.Visit(BD->getBody());
+
+  Vec = BV;
+  return BV;
+}
+
+std::pair<AnalysisDeclContext::referenced_decls_iterator,
+          AnalysisDeclContext::referenced_decls_iterator>
+AnalysisDeclContext::getReferencedBlockVars(const BlockDecl *BD) {
+  if (!ReferencedBlockVars)
+    ReferencedBlockVars = new llvm::DenseMap<const BlockDecl*,void*>();
+
+  DeclVec *V = LazyInitializeReferencedDecls(BD, (*ReferencedBlockVars)[BD], A);
+  return std::make_pair(V->begin(), V->end());
+}
+
+ManagedAnalysis *&AnalysisDeclContext::getAnalysisImpl(const void *tag) {
+  if (!ManagedAnalyses)
+    ManagedAnalyses = new ManagedAnalysisMap();
+  ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
+  return (*M)[tag];
+}
+
+//===----------------------------------------------------------------------===//
+// Cleanup.
+//===----------------------------------------------------------------------===//
+
+ManagedAnalysis::~ManagedAnalysis() {}
+
+AnalysisDeclContext::~AnalysisDeclContext() {
+  delete forcedBlkExprs;
+  delete ReferencedBlockVars;
+  // Release the managed analyses.
+  if (ManagedAnalyses) {
+    ManagedAnalysisMap *M = (ManagedAnalysisMap*) ManagedAnalyses;
+    for (ManagedAnalysisMap::iterator I = M->begin(), E = M->end(); I!=E; ++I)
+      delete I->second;  
+    delete M;
+  }
+}
+
+AnalysisDeclContextManager::~AnalysisDeclContextManager() {
+  for (ContextMap::iterator I = Contexts.begin(), E = Contexts.end(); I!=E; ++I)
+    delete I->second;
+}
+
+LocationContext::~LocationContext() {}
+
+LocationContextManager::~LocationContextManager() {
+  clear();
+}
+
+void LocationContextManager::clear() {
+  for (llvm::FoldingSet<LocationContext>::iterator I = Contexts.begin(),
+       E = Contexts.end(); I != E; ) {
+    LocationContext *LC = &*I;
+    ++I;
+    delete LC;
+  }
+
+  Contexts.clear();
+}
+
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
new file mode 100644
index 0000000..2f1f1cb
--- /dev/null
+++ b/clang/lib/Analysis/CFG.cpp
@@ -0,0 +1,3977 @@
+//===--- CFG.cpp - Classes for representing and building CFGs----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the CFG and CFGBuilder classes for representing and
+//  building Control-Flow Graphs (CFGs) from ASTs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/SaveAndRestore.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/PrettyPrinter.h"
+#include "clang/AST/CharUnits.h"
+#include "clang/Basic/AttrKinds.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Format.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/OwningPtr.h"
+
+using namespace clang;
+
+namespace {
+
+static SourceLocation GetEndLoc(Decl *D) {
+  if (VarDecl *VD = dyn_cast<VarDecl>(D))
+    if (Expr *Ex = VD->getInit())
+      return Ex->getSourceRange().getEnd();
+  return D->getLocation();
+}
+
+class CFGBuilder;
+  
+/// The CFG builder uses a recursive algorithm to build the CFG.  When
+///  we process an expression, sometimes we know that we must add the
+///  subexpressions as block-level expressions.  For example:
+///
+///    exp1 || exp2
+///
+///  When processing the '||' expression, we know that exp1 and exp2
+///  need to be added as block-level expressions, even though they
+///  might not normally need to be.  AddStmtChoice records this
+///  contextual information.  If AddStmtChoice is 'NotAlwaysAdd', then
+///  the builder has an option not to add a subexpression as a
+///  block-level expression.
+///
+class AddStmtChoice {
+public:
+  enum Kind { NotAlwaysAdd = 0, AlwaysAdd = 1 };
+
+  AddStmtChoice(Kind a_kind = NotAlwaysAdd) : kind(a_kind) {}
+
+  bool alwaysAdd(CFGBuilder &builder,
+                 const Stmt *stmt) const;
+
+  /// Return a copy of this object, except with the 'always-add' bit
+  ///  set as specified.
+  AddStmtChoice withAlwaysAdd(bool alwaysAdd) const {
+    return AddStmtChoice(alwaysAdd ? AlwaysAdd : NotAlwaysAdd);
+  }
+
+private:
+  Kind kind;
+};
+
+/// LocalScope - Node in tree of local scopes created for C++ implicit
+/// destructor calls generation. It contains list of automatic variables
+/// declared in the scope and link to position in previous scope this scope
+/// began in.
+///
+/// The process of creating local scopes is as follows:
+/// - Init CFGBuilder::ScopePos with invalid position (equivalent for null),
+/// - Before processing statements in scope (e.g. CompoundStmt) create
+///   LocalScope object using CFGBuilder::ScopePos as link to previous scope
+///   and set CFGBuilder::ScopePos to the end of new scope,
+/// - On every occurrence of VarDecl increase CFGBuilder::ScopePos if it points
+///   at this VarDecl,
+/// - For every normal (without jump) end of scope add to CFGBlock destructors
+///   for objects in the current scope,
+/// - For every jump add to CFGBlock destructors for objects
+///   between CFGBuilder::ScopePos and local scope position saved for jump
+///   target. Thanks to C++ restrictions on goto jumps we can be sure that
+///   jump target position will be on the path to root from CFGBuilder::ScopePos
+///   (adding any variable that doesn't need constructor to be called to
+///   LocalScope can break this assumption),
+///
+class LocalScope {
+public:
+  typedef BumpVector<VarDecl*> AutomaticVarsTy;
+
+  /// const_iterator - Iterates local scope backwards and jumps to previous
+  /// scope on reaching the beginning of currently iterated scope.
+  class const_iterator {
+    const LocalScope* Scope;
+
+    /// VarIter is guaranteed to be greater then 0 for every valid iterator.
+    /// Invalid iterator (with null Scope) has VarIter equal to 0.
+    unsigned VarIter;
+
+  public:
+    /// Create invalid iterator. Dereferencing invalid iterator is not allowed.
+    /// Incrementing invalid iterator is allowed and will result in invalid
+    /// iterator.
+    const_iterator()
+        : Scope(NULL), VarIter(0) {}
+
+    /// Create valid iterator. In case when S.Prev is an invalid iterator and
+    /// I is equal to 0, this will create invalid iterator.
+    const_iterator(const LocalScope& S, unsigned I)
+        : Scope(&S), VarIter(I) {
+      // Iterator to "end" of scope is not allowed. Handle it by going up
+      // in scopes tree possibly up to invalid iterator in the root.
+      if (VarIter == 0 && Scope)
+        *this = Scope->Prev;
+    }
+
+    VarDecl *const* operator->() const {
+      assert (Scope && "Dereferencing invalid iterator is not allowed");
+      assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
+      return &Scope->Vars[VarIter - 1];
+    }
+    VarDecl *operator*() const {
+      return *this->operator->();
+    }
+
+    const_iterator &operator++() {
+      if (!Scope)
+        return *this;
+
+      assert (VarIter != 0 && "Iterator has invalid value of VarIter member");
+      --VarIter;
+      if (VarIter == 0)
+        *this = Scope->Prev;
+      return *this;
+    }
+    const_iterator operator++(int) {
+      const_iterator P = *this;
+      ++*this;
+      return P;
+    }
+
+    bool operator==(const const_iterator &rhs) const {
+      return Scope == rhs.Scope && VarIter == rhs.VarIter;
+    }
+    bool operator!=(const const_iterator &rhs) const {
+      return !(*this == rhs);
+    }
+
+    operator bool() const {
+      return *this != const_iterator();
+    }
+
+    int distance(const_iterator L);
+  };
+
+  friend class const_iterator;
+
+private:
+  BumpVectorContext ctx;
+  
+  /// Automatic variables in order of declaration.
+  AutomaticVarsTy Vars;
+  /// Iterator to variable in previous scope that was declared just before
+  /// begin of this scope.
+  const_iterator Prev;
+
+public:
+  /// Constructs empty scope linked to previous scope in specified place.
+  LocalScope(BumpVectorContext &ctx, const_iterator P)
+      : ctx(ctx), Vars(ctx, 4), Prev(P) {}
+
+  /// Begin of scope in direction of CFG building (backwards).
+  const_iterator begin() const { return const_iterator(*this, Vars.size()); }
+
+  void addVar(VarDecl *VD) {
+    Vars.push_back(VD, ctx);
+  }
+};
+
+/// distance - Calculates distance from this to L. L must be reachable from this
+/// (with use of ++ operator). Cost of calculating the distance is linear w.r.t.
+/// number of scopes between this and L.
+int LocalScope::const_iterator::distance(LocalScope::const_iterator L) {
+  int D = 0;
+  const_iterator F = *this;
+  while (F.Scope != L.Scope) {
+    assert (F != const_iterator()
+        && "L iterator is not reachable from F iterator.");
+    D += F.VarIter;
+    F = F.Scope->Prev;
+  }
+  D += F.VarIter - L.VarIter;
+  return D;
+}
+
+/// BlockScopePosPair - Structure for specifying position in CFG during its
+/// build process. It consists of CFGBlock that specifies position in CFG graph
+/// and  LocalScope::const_iterator that specifies position in LocalScope graph.
+struct BlockScopePosPair {
+  BlockScopePosPair() : block(0) {}
+  BlockScopePosPair(CFGBlock *b, LocalScope::const_iterator scopePos)
+      : block(b), scopePosition(scopePos) {}
+
+  CFGBlock *block;
+  LocalScope::const_iterator scopePosition;
+};
+
+/// TryResult - a class representing a variant over the values
+///  'true', 'false', or 'unknown'.  This is returned by tryEvaluateBool,
+///  and is used by the CFGBuilder to decide if a branch condition
+///  can be decided up front during CFG construction.
+class TryResult {
+  int X;
+public:
+  TryResult(bool b) : X(b ? 1 : 0) {}
+  TryResult() : X(-1) {}
+  
+  bool isTrue() const { return X == 1; }
+  bool isFalse() const { return X == 0; }
+  bool isKnown() const { return X >= 0; }
+  void negate() {
+    assert(isKnown());
+    X ^= 0x1;
+  }
+};
+
+/// CFGBuilder - This class implements CFG construction from an AST.
+///   The builder is stateful: an instance of the builder should be used to only
+///   construct a single CFG.
+///
+///   Example usage:
+///
+///     CFGBuilder builder;
+///     CFG* cfg = builder.BuildAST(stmt1);
+///
+///  CFG construction is done via a recursive walk of an AST.  We actually parse
+///  the AST in reverse order so that the successor of a basic block is
+///  constructed prior to its predecessor.  This allows us to nicely capture
+///  implicit fall-throughs without extra basic blocks.
+///
+class CFGBuilder {
+  typedef BlockScopePosPair JumpTarget;
+  typedef BlockScopePosPair JumpSource;
+
+  ASTContext *Context;
+  OwningPtr<CFG> cfg;
+
+  CFGBlock *Block;
+  CFGBlock *Succ;
+  JumpTarget ContinueJumpTarget;
+  JumpTarget BreakJumpTarget;
+  CFGBlock *SwitchTerminatedBlock;
+  CFGBlock *DefaultCaseBlock;
+  CFGBlock *TryTerminatedBlock;
+  
+  // Current position in local scope.
+  LocalScope::const_iterator ScopePos;
+
+  // LabelMap records the mapping from Label expressions to their jump targets.
+  typedef llvm::DenseMap<LabelDecl*, JumpTarget> LabelMapTy;
+  LabelMapTy LabelMap;
+
+  // A list of blocks that end with a "goto" that must be backpatched to their
+  // resolved targets upon completion of CFG construction.
+  typedef std::vector<JumpSource> BackpatchBlocksTy;
+  BackpatchBlocksTy BackpatchBlocks;
+
+  // A list of labels whose address has been taken (for indirect gotos).
+  typedef llvm::SmallPtrSet<LabelDecl*, 5> LabelSetTy;
+  LabelSetTy AddressTakenLabels;
+
+  bool badCFG;
+  const CFG::BuildOptions &BuildOpts;
+  
+  // State to track for building switch statements.
+  bool switchExclusivelyCovered;
+  Expr::EvalResult *switchCond;
+  
+  CFG::BuildOptions::ForcedBlkExprs::value_type *cachedEntry;
+  const Stmt *lastLookup;
+
+  // Caches boolean evaluations of expressions to avoid multiple re-evaluations
+  // during construction of branches for chained logical operators.
+  typedef llvm::DenseMap<Expr *, TryResult> CachedBoolEvalsTy;
+  CachedBoolEvalsTy CachedBoolEvals;
+
+public:
+  explicit CFGBuilder(ASTContext *astContext,
+                      const CFG::BuildOptions &buildOpts) 
+    : Context(astContext), cfg(new CFG()), // crew a new CFG
+      Block(NULL), Succ(NULL),
+      SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL),
+      TryTerminatedBlock(NULL), badCFG(false), BuildOpts(buildOpts), 
+      switchExclusivelyCovered(false), switchCond(0),
+      cachedEntry(0), lastLookup(0) {}
+
+  // buildCFG - Used by external clients to construct the CFG.
+  CFG* buildCFG(const Decl *D, Stmt *Statement);
+
+  bool alwaysAdd(const Stmt *stmt);
+  
+private:
+  // Visitors to walk an AST and construct the CFG.
+  CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc);
+  CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc);
+  CFGBlock *VisitBreakStmt(BreakStmt *B);
+  CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S);
+  CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E,
+      AddStmtChoice asc);
+  CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
+  CFGBlock *VisitCXXTryStmt(CXXTryStmt *S);
+  CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S);
+  CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E, 
+                                      AddStmtChoice asc);
+  CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc);
+  CFGBlock *VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
+                                       AddStmtChoice asc);
+  CFGBlock *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C, 
+                                        AddStmtChoice asc);
+  CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc);
+  CFGBlock *VisitCaseStmt(CaseStmt *C);
+  CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc);
+  CFGBlock *VisitCompoundStmt(CompoundStmt *C);
+  CFGBlock *VisitConditionalOperator(AbstractConditionalOperator *C,
+                                     AddStmtChoice asc);
+  CFGBlock *VisitContinueStmt(ContinueStmt *C);
+  CFGBlock *VisitDeclStmt(DeclStmt *DS);
+  CFGBlock *VisitDeclSubExpr(DeclStmt *DS);
+  CFGBlock *VisitDefaultStmt(DefaultStmt *D);
+  CFGBlock *VisitDoStmt(DoStmt *D);
+  CFGBlock *VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc);
+  CFGBlock *VisitForStmt(ForStmt *F);
+  CFGBlock *VisitGotoStmt(GotoStmt *G);
+  CFGBlock *VisitIfStmt(IfStmt *I);
+  CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc);
+  CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I);
+  CFGBlock *VisitLabelStmt(LabelStmt *L);
+  CFGBlock *VisitLambdaExpr(LambdaExpr *L);
+  CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc);
+  CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
+  CFGBlock *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S);
+  CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
+  CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
+  CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
+  CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
+  CFGBlock *VisitReturnStmt(ReturnStmt *R);
+  CFGBlock *VisitPseudoObjectExpr(PseudoObjectExpr *E);
+  CFGBlock *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
+                                          AddStmtChoice asc);
+  CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc);
+  CFGBlock *VisitSwitchStmt(SwitchStmt *S);
+  CFGBlock *VisitUnaryOperator(UnaryOperator *U, AddStmtChoice asc);
+  CFGBlock *VisitWhileStmt(WhileStmt *W);
+
+  CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd);
+  CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc);
+  CFGBlock *VisitChildren(Stmt *S);
+  CFGBlock *VisitNoRecurse(Expr *E, AddStmtChoice asc);
+
+  // Visitors to walk an AST and generate destructors of temporaries in
+  // full expression.
+  CFGBlock *VisitForTemporaryDtors(Stmt *E, bool BindToTemporary = false);
+  CFGBlock *VisitChildrenForTemporaryDtors(Stmt *E);
+  CFGBlock *VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E);
+  CFGBlock *VisitCXXBindTemporaryExprForTemporaryDtors(CXXBindTemporaryExpr *E,
+      bool BindToTemporary);
+  CFGBlock *
+  VisitConditionalOperatorForTemporaryDtors(AbstractConditionalOperator *E,
+                                            bool BindToTemporary);
+
+  // NYS == Not Yet Supported
+  CFGBlock *NYS() {
+    badCFG = true;
+    return Block;
+  }
+
+  void autoCreateBlock() { if (!Block) Block = createBlock(); }
+  CFGBlock *createBlock(bool add_successor = true);
+  CFGBlock *createNoReturnBlock();
+
+  CFGBlock *addStmt(Stmt *S) {
+    return Visit(S, AddStmtChoice::AlwaysAdd);
+  }
+  CFGBlock *addInitializer(CXXCtorInitializer *I);
+  void addAutomaticObjDtors(LocalScope::const_iterator B,
+                            LocalScope::const_iterator E, Stmt *S);
+  void addImplicitDtorsForDestructor(const CXXDestructorDecl *DD);
+
+  // Local scopes creation.
+  LocalScope* createOrReuseLocalScope(LocalScope* Scope);
+
+  void addLocalScopeForStmt(Stmt *S);
+  LocalScope* addLocalScopeForDeclStmt(DeclStmt *DS, LocalScope* Scope = NULL);
+  LocalScope* addLocalScopeForVarDecl(VarDecl *VD, LocalScope* Scope = NULL);
+
+  void addLocalScopeAndDtors(Stmt *S);
+
+  // Interface to CFGBlock - adding CFGElements.
+  void appendStmt(CFGBlock *B, const Stmt *S) {
+    if (alwaysAdd(S) && cachedEntry)
+      cachedEntry->second = B;
+
+    // All block-level expressions should have already been IgnoreParens()ed.
+    assert(!isa<Expr>(S) || cast<Expr>(S)->IgnoreParens() == S);
+    B->appendStmt(const_cast<Stmt*>(S), cfg->getBumpVectorContext());
+  }
+  void appendInitializer(CFGBlock *B, CXXCtorInitializer *I) {
+    B->appendInitializer(I, cfg->getBumpVectorContext());
+  }
+  void appendBaseDtor(CFGBlock *B, const CXXBaseSpecifier *BS) {
+    B->appendBaseDtor(BS, cfg->getBumpVectorContext());
+  }
+  void appendMemberDtor(CFGBlock *B, FieldDecl *FD) {
+    B->appendMemberDtor(FD, cfg->getBumpVectorContext());
+  }
+  void appendTemporaryDtor(CFGBlock *B, CXXBindTemporaryExpr *E) {
+    B->appendTemporaryDtor(E, cfg->getBumpVectorContext());
+  }
+  void appendAutomaticObjDtor(CFGBlock *B, VarDecl *VD, Stmt *S) {
+    B->appendAutomaticObjDtor(VD, S, cfg->getBumpVectorContext());
+  }
+
+  void prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
+      LocalScope::const_iterator B, LocalScope::const_iterator E);
+
+  void addSuccessor(CFGBlock *B, CFGBlock *S) {
+    B->addSuccessor(S, cfg->getBumpVectorContext());
+  }
+
+  /// Try and evaluate an expression to an integer constant.
+  bool tryEvaluate(Expr *S, Expr::EvalResult &outResult) {
+    if (!BuildOpts.PruneTriviallyFalseEdges)
+      return false;
+    return !S->isTypeDependent() && 
+           !S->isValueDependent() &&
+           S->EvaluateAsRValue(outResult, *Context);
+  }
+
+  /// tryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
+  /// if we can evaluate to a known value, otherwise return -1.
+  TryResult tryEvaluateBool(Expr *S) {
+    if (!BuildOpts.PruneTriviallyFalseEdges ||
+        S->isTypeDependent() || S->isValueDependent())
+      return TryResult();
+
+    if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(S)) {
+      if (Bop->isLogicalOp()) {
+        // Check the cache first.
+        CachedBoolEvalsTy::iterator I = CachedBoolEvals.find(S);
+        if (I != CachedBoolEvals.end())
+          return I->second; // already in map;
+
+        // Retrieve result at first, or the map might be updated.
+        TryResult Result = evaluateAsBooleanConditionNoCache(S);
+        CachedBoolEvals[S] = Result; // update or insert
+        return Result;
+      }
+    }
+
+    return evaluateAsBooleanConditionNoCache(S);
+  }
+
+  /// \brief Evaluate as boolean \param E without using the cache.
+  TryResult evaluateAsBooleanConditionNoCache(Expr *E) {
+    if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(E)) {
+      if (Bop->isLogicalOp()) {
+        TryResult LHS = tryEvaluateBool(Bop->getLHS());
+        if (LHS.isKnown()) {
+          // We were able to evaluate the LHS, see if we can get away with not
+          // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
+          if (LHS.isTrue() == (Bop->getOpcode() == BO_LOr))
+            return LHS.isTrue();
+
+          TryResult RHS = tryEvaluateBool(Bop->getRHS());
+          if (RHS.isKnown()) {
+            if (Bop->getOpcode() == BO_LOr)
+              return LHS.isTrue() || RHS.isTrue();
+            else
+              return LHS.isTrue() && RHS.isTrue();
+          }
+        } else {
+          TryResult RHS = tryEvaluateBool(Bop->getRHS());
+          if (RHS.isKnown()) {
+            // We can't evaluate the LHS; however, sometimes the result
+            // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
+            if (RHS.isTrue() == (Bop->getOpcode() == BO_LOr))
+              return RHS.isTrue();
+          }
+        }
+
+        return TryResult();
+      }
+    }
+
+    bool Result;
+    if (E->EvaluateAsBooleanCondition(Result, *Context))
+      return Result;
+
+    return TryResult();
+  }
+  
+};
+
+inline bool AddStmtChoice::alwaysAdd(CFGBuilder &builder,
+                                     const Stmt *stmt) const {
+  return builder.alwaysAdd(stmt) || kind == AlwaysAdd;
+}
+
+bool CFGBuilder::alwaysAdd(const Stmt *stmt) {
+  bool shouldAdd = BuildOpts.alwaysAdd(stmt);
+  
+  if (!BuildOpts.forcedBlkExprs)
+    return shouldAdd;
+
+  if (lastLookup == stmt) {  
+    if (cachedEntry) {
+      assert(cachedEntry->first == stmt);
+      return true;
+    }
+    return shouldAdd;
+  }
+  
+  lastLookup = stmt;
+
+  // Perform the lookup!
+  CFG::BuildOptions::ForcedBlkExprs *fb = *BuildOpts.forcedBlkExprs;
+
+  if (!fb) {
+    // No need to update 'cachedEntry', since it will always be null.
+    assert(cachedEntry == 0);
+    return shouldAdd;
+  }
+
+  CFG::BuildOptions::ForcedBlkExprs::iterator itr = fb->find(stmt);
+  if (itr == fb->end()) {
+    cachedEntry = 0;
+    return shouldAdd;
+  }
+
+  cachedEntry = &*itr;
+  return true;
+}
+  
+// FIXME: Add support for dependent-sized array types in C++?
+// Does it even make sense to build a CFG for an uninstantiated template?
+static const VariableArrayType *FindVA(const Type *t) {
+  while (const ArrayType *vt = dyn_cast<ArrayType>(t)) {
+    if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt))
+      if (vat->getSizeExpr())
+        return vat;
+
+    t = vt->getElementType().getTypePtr();
+  }
+
+  return 0;
+}
+
+/// BuildCFG - Constructs a CFG from an AST (a Stmt*).  The AST can represent an
+///  arbitrary statement.  Examples include a single expression or a function
+///  body (compound statement).  The ownership of the returned CFG is
+///  transferred to the caller.  If CFG construction fails, this method returns
+///  NULL.
+CFG* CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) {
+  assert(cfg.get());
+  if (!Statement)
+    return NULL;
+
+  // Create an empty block that will serve as the exit block for the CFG.  Since
+  // this is the first block added to the CFG, it will be implicitly registered
+  // as the exit block.
+  Succ = createBlock();
+  assert(Succ == &cfg->getExit());
+  Block = NULL;  // the EXIT block is empty.  Create all other blocks lazily.
+
+  if (BuildOpts.AddImplicitDtors)
+    if (const CXXDestructorDecl *DD = dyn_cast_or_null<CXXDestructorDecl>(D))
+      addImplicitDtorsForDestructor(DD);
+
+  // Visit the statements and create the CFG.
+  CFGBlock *B = addStmt(Statement);
+
+  if (badCFG)
+    return NULL;
+
+  // For C++ constructor add initializers to CFG.
+  if (const CXXConstructorDecl *CD = dyn_cast_or_null<CXXConstructorDecl>(D)) {
+    for (CXXConstructorDecl::init_const_reverse_iterator I = CD->init_rbegin(),
+        E = CD->init_rend(); I != E; ++I) {
+      B = addInitializer(*I);
+      if (badCFG)
+        return NULL;
+    }
+  }
+
+  if (B)
+    Succ = B;
+
+  // Backpatch the gotos whose label -> block mappings we didn't know when we
+  // encountered them.
+  for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(),
+                                   E = BackpatchBlocks.end(); I != E; ++I ) {
+
+    CFGBlock *B = I->block;
+    GotoStmt *G = cast<GotoStmt>(B->getTerminator());
+    LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
+
+    // If there is no target for the goto, then we are looking at an
+    // incomplete AST.  Handle this by not registering a successor.
+    if (LI == LabelMap.end()) continue;
+
+    JumpTarget JT = LI->second;
+    prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
+                                           JT.scopePosition);
+    addSuccessor(B, JT.block);
+  }
+
+  // Add successors to the Indirect Goto Dispatch block (if we have one).
+  if (CFGBlock *B = cfg->getIndirectGotoBlock())
+    for (LabelSetTy::iterator I = AddressTakenLabels.begin(),
+                              E = AddressTakenLabels.end(); I != E; ++I ) {
+      
+      // Lookup the target block.
+      LabelMapTy::iterator LI = LabelMap.find(*I);
+
+      // If there is no target block that contains label, then we are looking
+      // at an incomplete AST.  Handle this by not registering a successor.
+      if (LI == LabelMap.end()) continue;
+      
+      addSuccessor(B, LI->second.block);
+    }
+
+  // Create an empty entry block that has no predecessors.
+  cfg->setEntry(createBlock());
+
+  return cfg.take();
+}
+
+/// createBlock - Used to lazily create blocks that are connected
+///  to the current (global) succcessor.
+CFGBlock *CFGBuilder::createBlock(bool add_successor) {
+  CFGBlock *B = cfg->createBlock();
+  if (add_successor && Succ)
+    addSuccessor(B, Succ);
+  return B;
+}
+
+/// createNoReturnBlock - Used to create a block is a 'noreturn' point in the
+/// CFG. It is *not* connected to the current (global) successor, and instead
+/// directly tied to the exit block in order to be reachable.
+CFGBlock *CFGBuilder::createNoReturnBlock() {
+  CFGBlock *B = createBlock(false);
+  B->setHasNoReturnElement();
+  addSuccessor(B, &cfg->getExit());
+  return B;
+}
+
+/// addInitializer - Add C++ base or member initializer element to CFG.
+CFGBlock *CFGBuilder::addInitializer(CXXCtorInitializer *I) {
+  if (!BuildOpts.AddInitializers)
+    return Block;
+
+  bool IsReference = false;
+  bool HasTemporaries = false;
+
+  // Destructors of temporaries in initialization expression should be called
+  // after initialization finishes.
+  Expr *Init = I->getInit();
+  if (Init) {
+    if (FieldDecl *FD = I->getAnyMember())
+      IsReference = FD->getType()->isReferenceType();
+    HasTemporaries = isa<ExprWithCleanups>(Init);
+
+    if (BuildOpts.AddImplicitDtors && HasTemporaries) {
+      // Generate destructors for temporaries in initialization expression.
+      VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
+          IsReference);
+    }
+  }
+
+  autoCreateBlock();
+  appendInitializer(Block, I);
+
+  if (Init) {
+    if (HasTemporaries) {
+      // For expression with temporaries go directly to subexpression to omit
+      // generating destructors for the second time.
+      return Visit(cast<ExprWithCleanups>(Init)->getSubExpr());
+    }
+    return Visit(Init);
+  }
+
+  return Block;
+}
+
+/// \brief Retrieve the type of the temporary object whose lifetime was 
+/// extended by a local reference with the given initializer.
+static QualType getReferenceInitTemporaryType(ASTContext &Context,
+                                              const Expr *Init) {
+  while (true) {
+    // Skip parentheses.
+    Init = Init->IgnoreParens();
+    
+    // Skip through cleanups.
+    if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init)) {
+      Init = EWC->getSubExpr();
+      continue;
+    }
+    
+    // Skip through the temporary-materialization expression.
+    if (const MaterializeTemporaryExpr *MTE
+          = dyn_cast<MaterializeTemporaryExpr>(Init)) {
+      Init = MTE->GetTemporaryExpr();
+      continue;
+    }
+    
+    // Skip derived-to-base and no-op casts.
+    if (const CastExpr *CE = dyn_cast<CastExpr>(Init)) {
+      if ((CE->getCastKind() == CK_DerivedToBase ||
+           CE->getCastKind() == CK_UncheckedDerivedToBase ||
+           CE->getCastKind() == CK_NoOp) &&
+          Init->getType()->isRecordType()) {
+        Init = CE->getSubExpr();
+        continue;
+      }
+    }
+    
+    // Skip member accesses into rvalues.
+    if (const MemberExpr *ME = dyn_cast<MemberExpr>(Init)) {
+      if (!ME->isArrow() && ME->getBase()->isRValue()) {
+        Init = ME->getBase();
+        continue;
+      }
+    }
+    
+    break;
+  }
+
+  return Init->getType();
+}
+  
+/// addAutomaticObjDtors - Add to current block automatic objects destructors
+/// for objects in range of local scope positions. Use S as trigger statement
+/// for destructors.
+void CFGBuilder::addAutomaticObjDtors(LocalScope::const_iterator B,
+                                      LocalScope::const_iterator E, Stmt *S) {
+  if (!BuildOpts.AddImplicitDtors)
+    return;
+
+  if (B == E)
+    return;
+
+  // We need to append the destructors in reverse order, but any one of them
+  // may be a no-return destructor which changes the CFG. As a result, buffer
+  // this sequence up and replay them in reverse order when appending onto the
+  // CFGBlock(s).
+  SmallVector<VarDecl*, 10> Decls;
+  Decls.reserve(B.distance(E));
+  for (LocalScope::const_iterator I = B; I != E; ++I)
+    Decls.push_back(*I);
+
+  for (SmallVectorImpl<VarDecl*>::reverse_iterator I = Decls.rbegin(),
+                                                   E = Decls.rend();
+       I != E; ++I) {
+    // If this destructor is marked as a no-return destructor, we need to
+    // create a new block for the destructor which does not have as a successor
+    // anything built thus far: control won't flow out of this block.
+    QualType Ty;
+    if ((*I)->getType()->isReferenceType()) {
+      Ty = getReferenceInitTemporaryType(*Context, (*I)->getInit());
+    } else {
+      Ty = Context->getBaseElementType((*I)->getType());
+    }
+    
+    const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
+    if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
+      Block = createNoReturnBlock();
+    else
+      autoCreateBlock();
+
+    appendAutomaticObjDtor(Block, *I, S);
+  }
+}
+
+/// addImplicitDtorsForDestructor - Add implicit destructors generated for
+/// base and member objects in destructor.
+void CFGBuilder::addImplicitDtorsForDestructor(const CXXDestructorDecl *DD) {
+  assert (BuildOpts.AddImplicitDtors
+      && "Can be called only when dtors should be added");
+  const CXXRecordDecl *RD = DD->getParent();
+
+  // At the end destroy virtual base objects.
+  for (CXXRecordDecl::base_class_const_iterator VI = RD->vbases_begin(),
+      VE = RD->vbases_end(); VI != VE; ++VI) {
+    const CXXRecordDecl *CD = VI->getType()->getAsCXXRecordDecl();
+    if (!CD->hasTrivialDestructor()) {
+      autoCreateBlock();
+      appendBaseDtor(Block, VI);
+    }
+  }
+
+  // Before virtual bases destroy direct base objects.
+  for (CXXRecordDecl::base_class_const_iterator BI = RD->bases_begin(),
+      BE = RD->bases_end(); BI != BE; ++BI) {
+    if (!BI->isVirtual()) {
+      const CXXRecordDecl *CD = BI->getType()->getAsCXXRecordDecl();
+      if (!CD->hasTrivialDestructor()) {
+        autoCreateBlock();
+        appendBaseDtor(Block, BI);
+      }
+    }
+  }
+
+  // First destroy member objects.
+  for (CXXRecordDecl::field_iterator FI = RD->field_begin(),
+      FE = RD->field_end(); FI != FE; ++FI) {
+    // Check for constant size array. Set type to array element type.
+    QualType QT = FI->getType();
+    if (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
+      if (AT->getSize() == 0)
+        continue;
+      QT = AT->getElementType();
+    }
+
+    if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
+      if (!CD->hasTrivialDestructor()) {
+        autoCreateBlock();
+        appendMemberDtor(Block, *FI);
+      }
+  }
+}
+
+/// createOrReuseLocalScope - If Scope is NULL create new LocalScope. Either
+/// way return valid LocalScope object.
+LocalScope* CFGBuilder::createOrReuseLocalScope(LocalScope* Scope) {
+  if (!Scope) {
+    llvm::BumpPtrAllocator &alloc = cfg->getAllocator();
+    Scope = alloc.Allocate<LocalScope>();
+    BumpVectorContext ctx(alloc);
+    new (Scope) LocalScope(ctx, ScopePos);
+  }
+  return Scope;
+}
+
+/// addLocalScopeForStmt - Add LocalScope to local scopes tree for statement
+/// that should create implicit scope (e.g. if/else substatements). 
+void CFGBuilder::addLocalScopeForStmt(Stmt *S) {
+  if (!BuildOpts.AddImplicitDtors)
+    return;
+
+  LocalScope *Scope = 0;
+
+  // For compound statement we will be creating explicit scope.
+  if (CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) {
+    for (CompoundStmt::body_iterator BI = CS->body_begin(), BE = CS->body_end()
+        ; BI != BE; ++BI) {
+      Stmt *SI = (*BI)->stripLabelLikeStatements();
+      if (DeclStmt *DS = dyn_cast<DeclStmt>(SI))
+        Scope = addLocalScopeForDeclStmt(DS, Scope);
+    }
+    return;
+  }
+
+  // For any other statement scope will be implicit and as such will be
+  // interesting only for DeclStmt.
+  if (DeclStmt *DS = dyn_cast<DeclStmt>(S->stripLabelLikeStatements()))
+    addLocalScopeForDeclStmt(DS);
+}
+
+/// addLocalScopeForDeclStmt - Add LocalScope for declaration statement. Will
+/// reuse Scope if not NULL.
+LocalScope* CFGBuilder::addLocalScopeForDeclStmt(DeclStmt *DS,
+                                                 LocalScope* Scope) {
+  if (!BuildOpts.AddImplicitDtors)
+    return Scope;
+
+  for (DeclStmt::decl_iterator DI = DS->decl_begin(), DE = DS->decl_end()
+      ; DI != DE; ++DI) {
+    if (VarDecl *VD = dyn_cast<VarDecl>(*DI))
+      Scope = addLocalScopeForVarDecl(VD, Scope);
+  }
+  return Scope;
+}
+
+/// addLocalScopeForVarDecl - Add LocalScope for variable declaration. It will
+/// create add scope for automatic objects and temporary objects bound to
+/// const reference. Will reuse Scope if not NULL.
+LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD,
+                                                LocalScope* Scope) {
+  if (!BuildOpts.AddImplicitDtors)
+    return Scope;
+
+  // Check if variable is local.
+  switch (VD->getStorageClass()) {
+  case SC_None:
+  case SC_Auto:
+  case SC_Register:
+    break;
+  default: return Scope;
+  }
+
+  // Check for const references bound to temporary. Set type to pointee.
+  QualType QT = VD->getType();
+  if (QT.getTypePtr()->isReferenceType()) {
+    if (!VD->extendsLifetimeOfTemporary())
+      return Scope;
+
+    QT = getReferenceInitTemporaryType(*Context, VD->getInit());
+  }
+
+  // Check for constant size array. Set type to array element type.
+  while (const ConstantArrayType *AT = Context->getAsConstantArrayType(QT)) {
+    if (AT->getSize() == 0)
+      return Scope;
+    QT = AT->getElementType();
+  }
+
+  // Check if type is a C++ class with non-trivial destructor.
+  if (const CXXRecordDecl *CD = QT->getAsCXXRecordDecl())
+    if (!CD->hasTrivialDestructor()) {
+      // Add the variable to scope
+      Scope = createOrReuseLocalScope(Scope);
+      Scope->addVar(VD);
+      ScopePos = Scope->begin();
+    }
+  return Scope;
+}
+
+/// addLocalScopeAndDtors - For given statement add local scope for it and
+/// add destructors that will cleanup the scope. Will reuse Scope if not NULL.
+void CFGBuilder::addLocalScopeAndDtors(Stmt *S) {
+  if (!BuildOpts.AddImplicitDtors)
+    return;
+
+  LocalScope::const_iterator scopeBeginPos = ScopePos;
+  addLocalScopeForStmt(S);
+  addAutomaticObjDtors(ScopePos, scopeBeginPos, S);
+}
+
+/// prependAutomaticObjDtorsWithTerminator - Prepend destructor CFGElements for
+/// variables with automatic storage duration to CFGBlock's elements vector.
+/// Elements will be prepended to physical beginning of the vector which
+/// happens to be logical end. Use blocks terminator as statement that specifies
+/// destructors call site.
+/// FIXME: This mechanism for adding automatic destructors doesn't handle
+/// no-return destructors properly.
+void CFGBuilder::prependAutomaticObjDtorsWithTerminator(CFGBlock *Blk,
+    LocalScope::const_iterator B, LocalScope::const_iterator E) {
+  BumpVectorContext &C = cfg->getBumpVectorContext();
+  CFGBlock::iterator InsertPos
+    = Blk->beginAutomaticObjDtorsInsert(Blk->end(), B.distance(E), C);
+  for (LocalScope::const_iterator I = B; I != E; ++I)
+    InsertPos = Blk->insertAutomaticObjDtor(InsertPos, *I,
+                                            Blk->getTerminator());
+}
+
+/// Visit - Walk the subtree of a statement and add extra
+///   blocks for ternary operators, &&, and ||.  We also process "," and
+///   DeclStmts (which may contain nested control-flow).
+CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
+  if (!S) {
+    badCFG = true;
+    return 0;
+  }
+
+  if (Expr *E = dyn_cast<Expr>(S))
+    S = E->IgnoreParens();
+
+  switch (S->getStmtClass()) {
+    default:
+      return VisitStmt(S, asc);
+
+    case Stmt::AddrLabelExprClass:
+      return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), asc);
+
+    case Stmt::BinaryConditionalOperatorClass:
+      return VisitConditionalOperator(cast<BinaryConditionalOperator>(S), asc);
+
+    case Stmt::BinaryOperatorClass:
+      return VisitBinaryOperator(cast<BinaryOperator>(S), asc);
+
+    case Stmt::BlockExprClass:
+      return VisitNoRecurse(cast<Expr>(S), asc);
+
+    case Stmt::BreakStmtClass:
+      return VisitBreakStmt(cast<BreakStmt>(S));
+
+    case Stmt::CallExprClass:
+    case Stmt::CXXOperatorCallExprClass:
+    case Stmt::CXXMemberCallExprClass:
+    case Stmt::UserDefinedLiteralClass:
+      return VisitCallExpr(cast<CallExpr>(S), asc);
+
+    case Stmt::CaseStmtClass:
+      return VisitCaseStmt(cast<CaseStmt>(S));
+
+    case Stmt::ChooseExprClass:
+      return VisitChooseExpr(cast<ChooseExpr>(S), asc);
+
+    case Stmt::CompoundStmtClass:
+      return VisitCompoundStmt(cast<CompoundStmt>(S));
+
+    case Stmt::ConditionalOperatorClass:
+      return VisitConditionalOperator(cast<ConditionalOperator>(S), asc);
+
+    case Stmt::ContinueStmtClass:
+      return VisitContinueStmt(cast<ContinueStmt>(S));
+
+    case Stmt::CXXCatchStmtClass:
+      return VisitCXXCatchStmt(cast<CXXCatchStmt>(S));
+
+    case Stmt::ExprWithCleanupsClass:
+      return VisitExprWithCleanups(cast<ExprWithCleanups>(S), asc);
+
+    case Stmt::CXXBindTemporaryExprClass:
+      return VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), asc);
+
+    case Stmt::CXXConstructExprClass:
+      return VisitCXXConstructExpr(cast<CXXConstructExpr>(S), asc);
+
+    case Stmt::CXXFunctionalCastExprClass:
+      return VisitCXXFunctionalCastExpr(cast<CXXFunctionalCastExpr>(S), asc);
+
+    case Stmt::CXXTemporaryObjectExprClass:
+      return VisitCXXTemporaryObjectExpr(cast<CXXTemporaryObjectExpr>(S), asc);
+
+    case Stmt::CXXThrowExprClass:
+      return VisitCXXThrowExpr(cast<CXXThrowExpr>(S));
+
+    case Stmt::CXXTryStmtClass:
+      return VisitCXXTryStmt(cast<CXXTryStmt>(S));
+
+    case Stmt::CXXForRangeStmtClass:
+      return VisitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
+
+    case Stmt::DeclStmtClass:
+      return VisitDeclStmt(cast<DeclStmt>(S));
+
+    case Stmt::DefaultStmtClass:
+      return VisitDefaultStmt(cast<DefaultStmt>(S));
+
+    case Stmt::DoStmtClass:
+      return VisitDoStmt(cast<DoStmt>(S));
+
+    case Stmt::ForStmtClass:
+      return VisitForStmt(cast<ForStmt>(S));
+
+    case Stmt::GotoStmtClass:
+      return VisitGotoStmt(cast<GotoStmt>(S));
+
+    case Stmt::IfStmtClass:
+      return VisitIfStmt(cast<IfStmt>(S));
+
+    case Stmt::ImplicitCastExprClass:
+      return VisitImplicitCastExpr(cast<ImplicitCastExpr>(S), asc);
+
+    case Stmt::IndirectGotoStmtClass:
+      return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S));
+
+    case Stmt::LabelStmtClass:
+      return VisitLabelStmt(cast<LabelStmt>(S));
+
+    case Stmt::LambdaExprClass:
+      return VisitLambdaExpr(cast<LambdaExpr>(S), asc);
+
+    case Stmt::AttributedStmtClass:
+      return Visit(cast<AttributedStmt>(S)->getSubStmt(), asc);
+
+    case Stmt::MemberExprClass:
+      return VisitMemberExpr(cast<MemberExpr>(S), asc);
+
+    case Stmt::NullStmtClass:
+      return Block;
+
+    case Stmt::ObjCAtCatchStmtClass:
+      return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
+
+    case Stmt::ObjCAutoreleasePoolStmtClass:
+    return VisitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(S));
+
+    case Stmt::ObjCAtSynchronizedStmtClass:
+      return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
+
+    case Stmt::ObjCAtThrowStmtClass:
+      return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S));
+
+    case Stmt::ObjCAtTryStmtClass:
+      return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S));
+
+    case Stmt::ObjCForCollectionStmtClass:
+      return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S));
+
+    case Stmt::OpaqueValueExprClass:
+      return Block;
+
+    case Stmt::PseudoObjectExprClass:
+      return VisitPseudoObjectExpr(cast<PseudoObjectExpr>(S));
+
+    case Stmt::ReturnStmtClass:
+      return VisitReturnStmt(cast<ReturnStmt>(S));
+
+    case Stmt::UnaryExprOrTypeTraitExprClass:
+      return VisitUnaryExprOrTypeTraitExpr(cast<UnaryExprOrTypeTraitExpr>(S),
+                                           asc);
+
+    case Stmt::StmtExprClass:
+      return VisitStmtExpr(cast<StmtExpr>(S), asc);
+
+    case Stmt::SwitchStmtClass:
+      return VisitSwitchStmt(cast<SwitchStmt>(S));
+
+    case Stmt::UnaryOperatorClass:
+      return VisitUnaryOperator(cast<UnaryOperator>(S), asc);
+
+    case Stmt::WhileStmtClass:
+      return VisitWhileStmt(cast<WhileStmt>(S));
+  }
+}
+
+CFGBlock *CFGBuilder::VisitStmt(Stmt *S, AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, S)) {
+    autoCreateBlock();
+    appendStmt(Block, S);
+  }
+
+  return VisitChildren(S);
+}
+
+/// VisitChildren - Visit the children of a Stmt.
+CFGBlock *CFGBuilder::VisitChildren(Stmt *Terminator) {
+  CFGBlock *lastBlock = Block;
+  for (Stmt::child_range I = Terminator->children(); I; ++I)
+    if (Stmt *child = *I)
+      if (CFGBlock *b = Visit(child))
+        lastBlock = b;
+
+  return lastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A,
+                                         AddStmtChoice asc) {
+  AddressTakenLabels.insert(A->getLabel());
+
+  if (asc.alwaysAdd(*this, A)) {
+    autoCreateBlock();
+    appendStmt(Block, A);
+  }
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitUnaryOperator(UnaryOperator *U,
+           AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, U)) {
+    autoCreateBlock();
+    appendStmt(Block, U);
+  }
+
+  return Visit(U->getSubExpr(), AddStmtChoice());
+}
+
+CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B,
+                                          AddStmtChoice asc) {
+  if (B->isLogicalOp()) { // && or ||
+    CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
+    appendStmt(ConfluenceBlock, B);
+
+    if (badCFG)
+      return 0;
+
+    // create the block evaluating the LHS
+    CFGBlock *LHSBlock = createBlock(false);
+    LHSBlock->setTerminator(B);
+
+    // create the block evaluating the RHS
+    Succ = ConfluenceBlock;
+    Block = NULL;
+    CFGBlock *RHSBlock = addStmt(B->getRHS());
+
+    if (RHSBlock) {
+      if (badCFG)
+        return 0;
+    } else {
+      // Create an empty block for cases where the RHS doesn't require
+      // any explicit statements in the CFG.
+      RHSBlock = createBlock();
+    }
+
+    // Generate the blocks for evaluating the LHS.
+    Block = LHSBlock;
+    CFGBlock *EntryLHSBlock = addStmt(B->getLHS());
+
+    // See if this is a known constant.
+    TryResult KnownVal = tryEvaluateBool(B->getLHS());
+    if (KnownVal.isKnown() && (B->getOpcode() == BO_LOr))
+      KnownVal.negate();
+
+    // Now link the LHSBlock with RHSBlock.
+    if (B->getOpcode() == BO_LOr) {
+      addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+      addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+    } else {
+      assert(B->getOpcode() == BO_LAnd);
+      addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+      addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+    }
+
+    return EntryLHSBlock;
+  }
+
+  if (B->getOpcode() == BO_Comma) { // ,
+    autoCreateBlock();
+    appendStmt(Block, B);
+    addStmt(B->getRHS());
+    return addStmt(B->getLHS());
+  }
+
+  if (B->isAssignmentOp()) {
+    if (asc.alwaysAdd(*this, B)) {
+      autoCreateBlock();
+      appendStmt(Block, B);
+    }
+    Visit(B->getLHS());
+    return Visit(B->getRHS());
+  }
+
+  if (asc.alwaysAdd(*this, B)) {
+    autoCreateBlock();
+    appendStmt(Block, B);
+  }
+
+  CFGBlock *RBlock = Visit(B->getRHS());
+  CFGBlock *LBlock = Visit(B->getLHS());
+  // If visiting RHS causes us to finish 'Block', e.g. the RHS is a StmtExpr
+  // containing a DoStmt, and the LHS doesn't create a new block, then we should
+  // return RBlock.  Otherwise we'll incorrectly return NULL.
+  return (LBlock ? LBlock : RBlock);
+}
+
+CFGBlock *CFGBuilder::VisitNoRecurse(Expr *E, AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, E)) {
+    autoCreateBlock();
+    appendStmt(Block, E);
+  }
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) {
+  // "break" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (badCFG)
+    return 0;
+
+  // Now create a new block that ends with the break statement.
+  Block = createBlock(false);
+  Block->setTerminator(B);
+
+  // If there is no target for the break, then we are looking at an incomplete
+  // AST.  This means that the CFG cannot be constructed.
+  if (BreakJumpTarget.block) {
+    addAutomaticObjDtors(ScopePos, BreakJumpTarget.scopePosition, B);
+    addSuccessor(Block, BreakJumpTarget.block);
+  } else
+    badCFG = true;
+
+
+  return Block;
+}
+
+static bool CanThrow(Expr *E, ASTContext &Ctx) {
+  QualType Ty = E->getType();
+  if (Ty->isFunctionPointerType())
+    Ty = Ty->getAs<PointerType>()->getPointeeType();
+  else if (Ty->isBlockPointerType())
+    Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
+
+  const FunctionType *FT = Ty->getAs<FunctionType>();
+  if (FT) {
+    if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT))
+      if (Proto->getExceptionSpecType() != EST_Uninstantiated &&
+          Proto->isNothrow(Ctx))
+        return false;
+  }
+  return true;
+}
+
+CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) {
+  // Compute the callee type.
+  QualType calleeType = C->getCallee()->getType();
+  if (calleeType == Context->BoundMemberTy) {
+    QualType boundType = Expr::findBoundMemberType(C->getCallee());
+
+    // We should only get a null bound type if processing a dependent
+    // CFG.  Recover by assuming nothing.
+    if (!boundType.isNull()) calleeType = boundType;
+  }
+
+  // If this is a call to a no-return function, this stops the block here.
+  bool NoReturn = getFunctionExtInfo(*calleeType).getNoReturn();
+
+  bool AddEHEdge = false;
+
+  // Languages without exceptions are assumed to not throw.
+  if (Context->getLangOpts().Exceptions) {
+    if (BuildOpts.AddEHEdges)
+      AddEHEdge = true;
+  }
+
+  if (FunctionDecl *FD = C->getDirectCallee()) {
+    if (FD->hasAttr<NoReturnAttr>())
+      NoReturn = true;
+    if (FD->hasAttr<NoThrowAttr>())
+      AddEHEdge = false;
+  }
+
+  if (!CanThrow(C->getCallee(), *Context))
+    AddEHEdge = false;
+
+  if (!NoReturn && !AddEHEdge)
+    return VisitStmt(C, asc.withAlwaysAdd(true));
+
+  if (Block) {
+    Succ = Block;
+    if (badCFG)
+      return 0;
+  }
+
+  if (NoReturn)
+    Block = createNoReturnBlock();
+  else
+    Block = createBlock();
+
+  appendStmt(Block, C);
+
+  if (AddEHEdge) {
+    // Add exceptional edges.
+    if (TryTerminatedBlock)
+      addSuccessor(Block, TryTerminatedBlock);
+    else
+      addSuccessor(Block, &cfg->getExit());
+  }
+
+  return VisitChildren(C);
+}
+
+CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C,
+                                      AddStmtChoice asc) {
+  CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
+  appendStmt(ConfluenceBlock, C);
+  if (badCFG)
+    return 0;
+
+  AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock *LHSBlock = Visit(C->getLHS(), alwaysAdd);
+  if (badCFG)
+    return 0;
+
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock *RHSBlock = Visit(C->getRHS(), alwaysAdd);
+  if (badCFG)
+    return 0;
+
+  Block = createBlock(false);
+  // See if this is a known constant.
+  const TryResult& KnownVal = tryEvaluateBool(C->getCond());
+  addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+  addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+  Block->setTerminator(C);
+  return addStmt(C->getCond());
+}
+
+
+CFGBlock *CFGBuilder::VisitCompoundStmt(CompoundStmt *C) {
+  addLocalScopeAndDtors(C);
+  CFGBlock *LastBlock = Block;
+
+  for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend();
+       I != E; ++I ) {
+    // If we hit a segment of code just containing ';' (NullStmts), we can
+    // get a null block back.  In such cases, just use the LastBlock
+    if (CFGBlock *newBlock = addStmt(*I))
+      LastBlock = newBlock;
+
+    if (badCFG)
+      return NULL;
+  }
+
+  return LastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitConditionalOperator(AbstractConditionalOperator *C,
+                                               AddStmtChoice asc) {
+  const BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(C);
+  const OpaqueValueExpr *opaqueValue = (BCO ? BCO->getOpaqueValue() : NULL);
+
+  // Create the confluence block that will "merge" the results of the ternary
+  // expression.
+  CFGBlock *ConfluenceBlock = Block ? Block : createBlock();
+  appendStmt(ConfluenceBlock, C);
+  if (badCFG)
+    return 0;
+
+  AddStmtChoice alwaysAdd = asc.withAlwaysAdd(true);
+
+  // Create a block for the LHS expression if there is an LHS expression.  A
+  // GCC extension allows LHS to be NULL, causing the condition to be the
+  // value that is returned instead.
+  //  e.g: x ?: y is shorthand for: x ? x : y;
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock *LHSBlock = 0;
+  const Expr *trueExpr = C->getTrueExpr();
+  if (trueExpr != opaqueValue) {
+    LHSBlock = Visit(C->getTrueExpr(), alwaysAdd);
+    if (badCFG)
+      return 0;
+    Block = NULL;
+  }
+  else
+    LHSBlock = ConfluenceBlock;
+
+  // Create the block for the RHS expression.
+  Succ = ConfluenceBlock;
+  CFGBlock *RHSBlock = Visit(C->getFalseExpr(), alwaysAdd);
+  if (badCFG)
+    return 0;
+
+  // Create the block that will contain the condition.
+  Block = createBlock(false);
+
+  // See if this is a known constant.
+  const TryResult& KnownVal = tryEvaluateBool(C->getCond());
+  addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+  addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+  Block->setTerminator(C);
+  Expr *condExpr = C->getCond();
+
+  if (opaqueValue) {
+    // Run the condition expression if it's not trivially expressed in
+    // terms of the opaque value (or if there is no opaque value).
+    if (condExpr != opaqueValue)
+      addStmt(condExpr);
+
+    // Before that, run the common subexpression if there was one.
+    // At least one of this or the above will be run.
+    return addStmt(BCO->getCommon());
+  }
+  
+  return addStmt(condExpr);
+}
+
+CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) {
+  // Check if the Decl is for an __label__.  If so, elide it from the
+  // CFG entirely.
+  if (isa<LabelDecl>(*DS->decl_begin()))
+    return Block;
+  
+  // This case also handles static_asserts.
+  if (DS->isSingleDecl())
+    return VisitDeclSubExpr(DS);
+
+  CFGBlock *B = 0;
+
+  // FIXME: Add a reverse iterator for DeclStmt to avoid this extra copy.
+  typedef SmallVector<Decl*,10> BufTy;
+  BufTy Buf(DS->decl_begin(), DS->decl_end());
+
+  for (BufTy::reverse_iterator I = Buf.rbegin(), E = Buf.rend(); I != E; ++I) {
+    // Get the alignment of the new DeclStmt, padding out to >=8 bytes.
+    unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8
+               ? 8 : llvm::AlignOf<DeclStmt>::Alignment;
+
+    // Allocate the DeclStmt using the BumpPtrAllocator.  It will get
+    // automatically freed with the CFG.
+    DeclGroupRef DG(*I);
+    Decl *D = *I;
+    void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
+    DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D));
+
+    // Append the fake DeclStmt to block.
+    B = VisitDeclSubExpr(DSNew);
+  }
+
+  return B;
+}
+
+/// VisitDeclSubExpr - Utility method to add block-level expressions for
+/// DeclStmts and initializers in them.
+CFGBlock *CFGBuilder::VisitDeclSubExpr(DeclStmt *DS) {
+  assert(DS->isSingleDecl() && "Can handle single declarations only.");
+  Decl *D = DS->getSingleDecl();
+ 
+  if (isa<StaticAssertDecl>(D)) {
+    // static_asserts aren't added to the CFG because they do not impact
+    // runtime semantics.
+    return Block;
+  }
+  
+  VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl());
+
+  if (!VD) {
+    autoCreateBlock();
+    appendStmt(Block, DS);
+    return Block;
+  }
+
+  bool IsReference = false;
+  bool HasTemporaries = false;
+
+  // Destructors of temporaries in initialization expression should be called
+  // after initialization finishes.
+  Expr *Init = VD->getInit();
+  if (Init) {
+    IsReference = VD->getType()->isReferenceType();
+    HasTemporaries = isa<ExprWithCleanups>(Init);
+
+    if (BuildOpts.AddImplicitDtors && HasTemporaries) {
+      // Generate destructors for temporaries in initialization expression.
+      VisitForTemporaryDtors(cast<ExprWithCleanups>(Init)->getSubExpr(),
+          IsReference);
+    }
+  }
+
+  autoCreateBlock();
+  appendStmt(Block, DS);
+  
+  // Keep track of the last non-null block, as 'Block' can be nulled out
+  // if the initializer expression is something like a 'while' in a
+  // statement-expression.
+  CFGBlock *LastBlock = Block;
+
+  if (Init) {
+    if (HasTemporaries) {
+      // For expression with temporaries go directly to subexpression to omit
+      // generating destructors for the second time.
+      ExprWithCleanups *EC = cast<ExprWithCleanups>(Init);
+      if (CFGBlock *newBlock = Visit(EC->getSubExpr()))
+        LastBlock = newBlock;
+    }
+    else {
+      if (CFGBlock *newBlock = Visit(Init))
+        LastBlock = newBlock;
+    }
+  }
+
+  // If the type of VD is a VLA, then we must process its size expressions.
+  for (const VariableArrayType* VA = FindVA(VD->getType().getTypePtr());
+       VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
+    Block = addStmt(VA->getSizeExpr());
+
+  // Remove variable from local scope.
+  if (ScopePos && VD == *ScopePos)
+    ++ScopePos;
+
+  return Block ? Block : LastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) {
+  // We may see an if statement in the middle of a basic block, or it may be the
+  // first statement we are processing.  In either case, we create a new basic
+  // block.  First, we create the blocks for the then...else statements, and
+  // then we create the block containing the if statement.  If we were in the
+  // middle of a block, we stop processing that block.  That block is then the
+  // implicit successor for the "then" and "else" clauses.
+
+  // Save local scope position because in case of condition variable ScopePos
+  // won't be restored when traversing AST.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scope for possible condition variable.
+  // Store scope position. Add implicit destructor.
+  if (VarDecl *VD = I->getConditionVariable()) {
+    LocalScope::const_iterator BeginScopePos = ScopePos;
+    addLocalScopeForVarDecl(VD);
+    addAutomaticObjDtors(ScopePos, BeginScopePos, I);
+  }
+
+  // The block we were processing is now finished.  Make it the successor
+  // block.
+  if (Block) {
+    Succ = Block;
+    if (badCFG)
+      return 0;
+  }
+
+  // Process the false branch.
+  CFGBlock *ElseBlock = Succ;
+
+  if (Stmt *Else = I->getElse()) {
+    SaveAndRestore<CFGBlock*> sv(Succ);
+
+    // NULL out Block so that the recursive call to Visit will
+    // create a new basic block.
+    Block = NULL;
+
+    // If branch is not a compound statement create implicit scope
+    // and add destructors.
+    if (!isa<CompoundStmt>(Else))
+      addLocalScopeAndDtors(Else);
+
+    ElseBlock = addStmt(Else);
+
+    if (!ElseBlock) // Can occur when the Else body has all NullStmts.
+      ElseBlock = sv.get();
+    else if (Block) {
+      if (badCFG)
+        return 0;
+    }
+  }
+
+  // Process the true branch.
+  CFGBlock *ThenBlock;
+  {
+    Stmt *Then = I->getThen();
+    assert(Then);
+    SaveAndRestore<CFGBlock*> sv(Succ);
+    Block = NULL;
+
+    // If branch is not a compound statement create implicit scope
+    // and add destructors.
+    if (!isa<CompoundStmt>(Then))
+      addLocalScopeAndDtors(Then);
+
+    ThenBlock = addStmt(Then);
+
+    if (!ThenBlock) {
+      // We can reach here if the "then" body has all NullStmts.
+      // Create an empty block so we can distinguish between true and false
+      // branches in path-sensitive analyses.
+      ThenBlock = createBlock(false);
+      addSuccessor(ThenBlock, sv.get());
+    } else if (Block) {
+      if (badCFG)
+        return 0;
+    }
+  }
+
+  // Now create a new block containing the if statement.
+  Block = createBlock(false);
+
+  // Set the terminator of the new block to the If statement.
+  Block->setTerminator(I);
+
+  // See if this is a known constant.
+  const TryResult &KnownVal = tryEvaluateBool(I->getCond());
+
+  // Now add the successors.
+  addSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock);
+  addSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock);
+
+  // Add the condition as the last statement in the new block.  This may create
+  // new blocks as the condition may contain control-flow.  Any newly created
+  // blocks will be pointed to be "Block".
+  Block = addStmt(I->getCond());
+
+  // Finally, if the IfStmt contains a condition variable, add both the IfStmt
+  // and the condition variable initialization to the CFG.
+  if (VarDecl *VD = I->getConditionVariable()) {
+    if (Expr *Init = VD->getInit()) {
+      autoCreateBlock();
+      appendStmt(Block, I->getConditionVariableDeclStmt());
+      addStmt(Init);
+    }
+  }
+
+  return Block;
+}
+
+
+CFGBlock *CFGBuilder::VisitReturnStmt(ReturnStmt *R) {
+  // If we were in the middle of a block we stop processing that block.
+  //
+  // NOTE: If a "return" appears in the middle of a block, this means that the
+  //       code afterwards is DEAD (unreachable).  We still keep a basic block
+  //       for that code; a simple "mark-and-sweep" from the entry block will be
+  //       able to report such dead blocks.
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  // The Exit block is the only successor.
+  addAutomaticObjDtors(ScopePos, LocalScope::const_iterator(), R);
+  addSuccessor(Block, &cfg->getExit());
+
+  // Add the return statement to the block.  This may create new blocks if R
+  // contains control-flow (short-circuit operations).
+  return VisitStmt(R, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock *CFGBuilder::VisitLabelStmt(LabelStmt *L) {
+  // Get the block of the labeled statement.  Add it to our map.
+  addStmt(L->getSubStmt());
+  CFGBlock *LabelBlock = Block;
+
+  if (!LabelBlock)              // This can happen when the body is empty, i.e.
+    LabelBlock = createBlock(); // scopes that only contains NullStmts.
+
+  assert(LabelMap.find(L->getDecl()) == LabelMap.end() &&
+         "label already in map");
+  LabelMap[L->getDecl()] = JumpTarget(LabelBlock, ScopePos);
+
+  // Labels partition blocks, so this is the end of the basic block we were
+  // processing (L is the block's label).  Because this is label (and we have
+  // already processed the substatement) there is no extra control-flow to worry
+  // about.
+  LabelBlock->setLabel(L);
+  if (badCFG)
+    return 0;
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary);
+  Block = NULL;
+
+  // This block is now the implicit successor of other blocks.
+  Succ = LabelBlock;
+
+  return LabelBlock;
+}
+
+CFGBlock *CFGBuilder::VisitLambdaExpr(LambdaExpr *E, AddStmtChoice asc) {
+  CFGBlock *LastBlock = VisitNoRecurse(E, asc);
+  for (LambdaExpr::capture_init_iterator it = E->capture_init_begin(),
+       et = E->capture_init_end(); it != et; ++it) {
+    if (Expr *Init = *it) {
+      CFGBlock *Tmp = Visit(Init);
+      if (Tmp != 0)
+        LastBlock = Tmp;
+    }
+  }
+  return LastBlock;
+}
+  
+CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) {
+  // Goto is a control-flow statement.  Thus we stop processing the current
+  // block and create a new one.
+
+  Block = createBlock(false);
+  Block->setTerminator(G);
+
+  // If we already know the mapping to the label block add the successor now.
+  LabelMapTy::iterator I = LabelMap.find(G->getLabel());
+
+  if (I == LabelMap.end())
+    // We will need to backpatch this block later.
+    BackpatchBlocks.push_back(JumpSource(Block, ScopePos));
+  else {
+    JumpTarget JT = I->second;
+    addAutomaticObjDtors(ScopePos, JT.scopePosition, G);
+    addSuccessor(Block, JT.block);
+  }
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) {
+  CFGBlock *LoopSuccessor = NULL;
+
+  // Save local scope position because in case of condition variable ScopePos
+  // won't be restored when traversing AST.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scope for init statement and possible condition variable.
+  // Add destructor for init statement and condition variable.
+  // Store scope position for continue statement.
+  if (Stmt *Init = F->getInit())
+    addLocalScopeForStmt(Init);
+  LocalScope::const_iterator LoopBeginScopePos = ScopePos;
+
+  if (VarDecl *VD = F->getConditionVariable())
+    addLocalScopeForVarDecl(VD);
+  LocalScope::const_iterator ContinueScopePos = ScopePos;
+
+  addAutomaticObjDtors(ScopePos, save_scope_pos.get(), F);
+
+  // "for" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (Block) {
+    if (badCFG)
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Save the current value for the break targets.
+  // All breaks should go to the code following the loop.
+  SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
+  BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock *ExitConditionBlock = createBlock(false);
+  CFGBlock *EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(F);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.
+  if (Stmt *C = F->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    if (badCFG)
+      return 0;
+    assert(Block == EntryConditionBlock ||
+           (Block == 0 && EntryConditionBlock == Succ));
+
+    // If this block contains a condition variable, add both the condition
+    // variable and initializer to the CFG.
+    if (VarDecl *VD = F->getConditionVariable()) {
+      if (Expr *Init = VD->getInit()) {
+        autoCreateBlock();
+        appendStmt(Block, F->getConditionVariableDeclStmt());
+        EntryConditionBlock = addStmt(Init);
+        assert(Block == EntryConditionBlock);
+      }
+    }
+
+    if (Block) {
+      if (badCFG)
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  TryResult KnownVal(true);
+
+  if (F->getCond())
+    KnownVal = tryEvaluateBool(F->getCond());
+
+  // Now create the loop body.
+  {
+    assert(F->getBody());
+
+   // Save the current values for Block, Succ, and continue targets.
+   SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
+   SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
+
+    // Create a new block to contain the (bottom) of the loop body.
+    Block = NULL;
+    
+    // Loop body should end with destructor of Condition variable (if any).
+    addAutomaticObjDtors(ScopePos, LoopBeginScopePos, F);
+
+    if (Stmt *I = F->getInc()) {
+      // Generate increment code in its own basic block.  This is the target of
+      // continue statements.
+      Succ = addStmt(I);
+    } else {
+      // No increment code.  Create a special, empty, block that is used as the
+      // target block for "looping back" to the start of the loop.
+      assert(Succ == EntryConditionBlock);
+      Succ = Block ? Block : createBlock();
+    }
+
+    // Finish up the increment (or empty) block if it hasn't been already.
+    if (Block) {
+      assert(Block == Succ);
+      if (badCFG)
+        return 0;
+      Block = 0;
+    }
+
+    ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
+
+    // The starting block for the loop increment is the block that should
+    // represent the 'loop target' for looping back to the start of the loop.
+    ContinueJumpTarget.block->setLoopTarget(F);
+
+    // If body is not a compound statement create implicit scope
+    // and add destructors.
+    if (!isa<CompoundStmt>(F->getBody()))
+      addLocalScopeAndDtors(F->getBody());
+
+    // Now populate the body block, and in the process create new blocks as we
+    // walk the body of the loop.
+    CFGBlock *BodyBlock = addStmt(F->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = ContinueJumpTarget.block;//can happen for "for (...;...;...);"
+    else if (badCFG)
+      return 0;
+
+    // This new body block is a successor to our "exit" condition block.
+    addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.  (the
+  // false branch).
+  addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // If the loop contains initialization, create a new block for those
+  // statements.  This block can also contain statements that precede the loop.
+  if (Stmt *I = F->getInit()) {
+    Block = createBlock();
+    return addStmt(I);
+  }
+
+  // There is no loop initialization.  We are thus basically a while loop.
+  // NULL out Block to force lazy block construction.
+  Block = NULL;
+  Succ = EntryConditionBlock;
+  return EntryConditionBlock;
+}
+
+CFGBlock *CFGBuilder::VisitMemberExpr(MemberExpr *M, AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, M)) {
+    autoCreateBlock();
+    appendStmt(Block, M);
+  }
+  return Visit(M->getBase());
+}
+
+CFGBlock *CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
+  // Objective-C fast enumeration 'for' statements:
+  //  http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC
+  //
+  //  for ( Type newVariable in collection_expression ) { statements }
+  //
+  //  becomes:
+  //
+  //   prologue:
+  //     1. collection_expression
+  //     T. jump to loop_entry
+  //   loop_entry:
+  //     1. side-effects of element expression
+  //     1. ObjCForCollectionStmt [performs binding to newVariable]
+  //     T. ObjCForCollectionStmt  TB, FB  [jumps to TB if newVariable != nil]
+  //   TB:
+  //     statements
+  //     T. jump to loop_entry
+  //   FB:
+  //     what comes after
+  //
+  //  and
+  //
+  //  Type existingItem;
+  //  for ( existingItem in expression ) { statements }
+  //
+  //  becomes:
+  //
+  //   the same with newVariable replaced with existingItem; the binding works
+  //   the same except that for one ObjCForCollectionStmt::getElement() returns
+  //   a DeclStmt and the other returns a DeclRefExpr.
+  //
+
+  CFGBlock *LoopSuccessor = 0;
+
+  if (Block) {
+    if (badCFG)
+      return 0;
+    LoopSuccessor = Block;
+    Block = 0;
+  } else
+    LoopSuccessor = Succ;
+
+  // Build the condition blocks.
+  CFGBlock *ExitConditionBlock = createBlock(false);
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(S);
+
+  // The last statement in the block should be the ObjCForCollectionStmt, which
+  // performs the actual binding to 'element' and determines if there are any
+  // more items in the collection.
+  appendStmt(ExitConditionBlock, S);
+  Block = ExitConditionBlock;
+
+  // Walk the 'element' expression to see if there are any side-effects.  We
+  // generate new blocks as necessary.  We DON'T add the statement by default to
+  // the CFG unless it contains control-flow.
+  CFGBlock *EntryConditionBlock = Visit(S->getElement(),
+                                        AddStmtChoice::NotAlwaysAdd);
+  if (Block) {
+    if (badCFG)
+      return 0;
+    Block = 0;
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // Now create the true branch.
+  {
+    // Save the current values for Succ, continue and break targets.
+    SaveAndRestore<CFGBlock*> save_Succ(Succ);
+    SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
+        save_break(BreakJumpTarget);
+
+    BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+    ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos);
+
+    CFGBlock *BodyBlock = addStmt(S->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;"
+    else if (Block) {
+      if (badCFG)
+        return 0;
+    }
+
+    // This new body block is a successor to our "exit" condition block.
+    addSuccessor(ExitConditionBlock, BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.
+  // (the false branch).
+  addSuccessor(ExitConditionBlock, LoopSuccessor);
+
+  // Now create a prologue block to contain the collection expression.
+  Block = createBlock();
+  return addStmt(S->getCollection());
+}
+
+CFGBlock *CFGBuilder::VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
+  // Inline the body.
+  return addStmt(S->getSubStmt());
+  // TODO: consider adding cleanups for the end of @autoreleasepool scope.
+}
+
+CFGBlock *CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S) {
+  // FIXME: Add locking 'primitives' to CFG for @synchronized.
+
+  // Inline the body.
+  CFGBlock *SyncBlock = addStmt(S->getSynchBody());
+
+  // The sync body starts its own basic block.  This makes it a little easier
+  // for diagnostic clients.
+  if (SyncBlock) {
+    if (badCFG)
+      return 0;
+
+    Block = 0;
+    Succ = SyncBlock;
+  }
+
+  // Add the @synchronized to the CFG.
+  autoCreateBlock();
+  appendStmt(Block, S);
+
+  // Inline the sync expression.
+  return addStmt(S->getSynchExpr());
+}
+
+CFGBlock *CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt *S) {
+  // FIXME
+  return NYS();
+}
+
+CFGBlock *CFGBuilder::VisitPseudoObjectExpr(PseudoObjectExpr *E) {
+  autoCreateBlock();
+
+  // Add the PseudoObject as the last thing.
+  appendStmt(Block, E);
+
+  CFGBlock *lastBlock = Block;  
+
+  // Before that, evaluate all of the semantics in order.  In
+  // CFG-land, that means appending them in reverse order.
+  for (unsigned i = E->getNumSemanticExprs(); i != 0; ) {
+    Expr *Semantic = E->getSemanticExpr(--i);
+
+    // If the semantic is an opaque value, we're being asked to bind
+    // it to its source expression.
+    if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Semantic))
+      Semantic = OVE->getSourceExpr();
+
+    if (CFGBlock *B = Visit(Semantic))
+      lastBlock = B;
+  }
+
+  return lastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitWhileStmt(WhileStmt *W) {
+  CFGBlock *LoopSuccessor = NULL;
+
+  // Save local scope position because in case of condition variable ScopePos
+  // won't be restored when traversing AST.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scope for possible condition variable.
+  // Store scope position for continue statement.
+  LocalScope::const_iterator LoopBeginScopePos = ScopePos;
+  if (VarDecl *VD = W->getConditionVariable()) {
+    addLocalScopeForVarDecl(VD);
+    addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
+  }
+
+  // "while" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (Block) {
+    if (badCFG)
+      return 0;
+    LoopSuccessor = Block;
+    Block = 0;
+  } else
+    LoopSuccessor = Succ;
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock *ExitConditionBlock = createBlock(false);
+  CFGBlock *EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(W);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.  Thus we update
+  // "Succ" after adding the condition.
+  if (Stmt *C = W->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    // The condition might finish the current 'Block'.
+    Block = EntryConditionBlock;
+
+    // If this block contains a condition variable, add both the condition
+    // variable and initializer to the CFG.
+    if (VarDecl *VD = W->getConditionVariable()) {
+      if (Expr *Init = VD->getInit()) {
+        autoCreateBlock();
+        appendStmt(Block, W->getConditionVariableDeclStmt());        
+        EntryConditionBlock = addStmt(Init);
+        assert(Block == EntryConditionBlock);
+      }
+    }
+
+    if (Block) {
+      if (badCFG)
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  const TryResult& KnownVal = tryEvaluateBool(W->getCond());
+
+  // Process the loop body.
+  {
+    assert(W->getBody());
+
+    // Save the current values for Block, Succ, and continue and break targets
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
+    SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
+        save_break(BreakJumpTarget);
+
+    // Create an empty block to represent the transition block for looping back
+    // to the head of the loop.
+    Block = 0;
+    assert(Succ == EntryConditionBlock);
+    Succ = createBlock();
+    Succ->setLoopTarget(W);
+    ContinueJumpTarget = JumpTarget(Succ, LoopBeginScopePos);
+
+    // All breaks should go to the code following the loop.
+    BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+
+    // NULL out Block to force lazy instantiation of blocks for the body.
+    Block = NULL;
+
+    // Loop body should end with destructor of Condition variable (if any).
+    addAutomaticObjDtors(ScopePos, LoopBeginScopePos, W);
+
+    // If body is not a compound statement create implicit scope
+    // and add destructors.
+    if (!isa<CompoundStmt>(W->getBody()))
+      addLocalScopeAndDtors(W->getBody());
+
+    // Create the body.  The returned block is the entry to the loop body.
+    CFGBlock *BodyBlock = addStmt(W->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = ContinueJumpTarget.block; // can happen for "while(...) ;"
+    else if (Block) {
+      if (badCFG)
+        return 0;
+    }
+
+    // Add the loop body entry as a successor to the condition.
+    addSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.  (the
+  // false branch).
+  addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // There can be no more statements in the condition block since we loop back
+  // to this block.  NULL out Block to force lazy creation of another block.
+  Block = NULL;
+
+  // Return the condition block, which is the dominating block for the loop.
+  Succ = EntryConditionBlock;
+  return EntryConditionBlock;
+}
+
+
+CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt *S) {
+  // FIXME: For now we pretend that @catch and the code it contains does not
+  //  exit.
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt *S) {
+  // FIXME: This isn't complete.  We basically treat @throw like a return
+  //  statement.
+
+  // If we were in the middle of a block we stop processing that block.
+  if (badCFG)
+    return 0;
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  // The Exit block is the only successor.
+  addSuccessor(Block, &cfg->getExit());
+
+  // Add the statement to the block.  This may create new blocks if S contains
+  // control-flow (short-circuit operations).
+  return VisitStmt(S, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock *CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr *T) {
+  // If we were in the middle of a block we stop processing that block.
+  if (badCFG)
+    return 0;
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  if (TryTerminatedBlock)
+    // The current try statement is the only successor.
+    addSuccessor(Block, TryTerminatedBlock);
+  else
+    // otherwise the Exit block is the only successor.
+    addSuccessor(Block, &cfg->getExit());
+
+  // Add the statement to the block.  This may create new blocks if S contains
+  // control-flow (short-circuit operations).
+  return VisitStmt(T, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock *CFGBuilder::VisitDoStmt(DoStmt *D) {
+  CFGBlock *LoopSuccessor = NULL;
+
+  // "do...while" is a control-flow statement.  Thus we stop processing the
+  // current block.
+  if (Block) {
+    if (badCFG)
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock *ExitConditionBlock = createBlock(false);
+  CFGBlock *EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(D);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.
+  if (Stmt *C = D->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    if (Block) {
+      if (badCFG)
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  const TryResult &KnownVal = tryEvaluateBool(D->getCond());
+
+  // Process the loop body.
+  CFGBlock *BodyBlock = NULL;
+  {
+    assert(D->getBody());
+
+    // Save the current values for Block, Succ, and continue and break targets
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
+    SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget),
+        save_break(BreakJumpTarget);
+
+    // All continues within this loop should go to the condition block
+    ContinueJumpTarget = JumpTarget(EntryConditionBlock, ScopePos);
+
+    // All breaks should go to the code following the loop.
+    BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+
+    // NULL out Block to force lazy instantiation of blocks for the body.
+    Block = NULL;
+
+    // If body is not a compound statement create implicit scope
+    // and add destructors.
+    if (!isa<CompoundStmt>(D->getBody()))
+      addLocalScopeAndDtors(D->getBody());
+
+    // Create the body.  The returned block is the entry to the loop body.
+    BodyBlock = addStmt(D->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)"
+    else if (Block) {
+      if (badCFG)
+        return 0;
+    }
+
+    if (!KnownVal.isFalse()) {
+      // Add an intermediate block between the BodyBlock and the
+      // ExitConditionBlock to represent the "loop back" transition.  Create an
+      // empty block to represent the transition block for looping back to the
+      // head of the loop.
+      // FIXME: Can we do this more efficiently without adding another block?
+      Block = NULL;
+      Succ = BodyBlock;
+      CFGBlock *LoopBackBlock = createBlock();
+      LoopBackBlock->setLoopTarget(D);
+
+      // Add the loop body entry as a successor to the condition.
+      addSuccessor(ExitConditionBlock, LoopBackBlock);
+    }
+    else
+      addSuccessor(ExitConditionBlock, NULL);
+  }
+
+  // Link up the condition block with the code that follows the loop.
+  // (the false branch).
+  addSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // There can be no more statements in the body block(s) since we loop back to
+  // the body.  NULL out Block to force lazy creation of another block.
+  Block = NULL;
+
+  // Return the loop body, which is the dominating block for the loop.
+  Succ = BodyBlock;
+  return BodyBlock;
+}
+
+CFGBlock *CFGBuilder::VisitContinueStmt(ContinueStmt *C) {
+  // "continue" is a control-flow statement.  Thus we stop processing the
+  // current block.
+  if (badCFG)
+    return 0;
+
+  // Now create a new block that ends with the continue statement.
+  Block = createBlock(false);
+  Block->setTerminator(C);
+
+  // If there is no target for the continue, then we are looking at an
+  // incomplete AST.  This means the CFG cannot be constructed.
+  if (ContinueJumpTarget.block) {
+    addAutomaticObjDtors(ScopePos, ContinueJumpTarget.scopePosition, C);
+    addSuccessor(Block, ContinueJumpTarget.block);
+  } else
+    badCFG = true;
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E,
+                                                    AddStmtChoice asc) {
+
+  if (asc.alwaysAdd(*this, E)) {
+    autoCreateBlock();
+    appendStmt(Block, E);
+  }
+
+  // VLA types have expressions that must be evaluated.
+  CFGBlock *lastBlock = Block;
+  
+  if (E->isArgumentType()) {
+    for (const VariableArrayType *VA =FindVA(E->getArgumentType().getTypePtr());
+         VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
+      lastBlock = addStmt(VA->getSizeExpr());
+  }
+  return lastBlock;
+}
+
+/// VisitStmtExpr - Utility method to handle (nested) statement
+///  expressions (a GCC extension).
+CFGBlock *CFGBuilder::VisitStmtExpr(StmtExpr *SE, AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, SE)) {
+    autoCreateBlock();
+    appendStmt(Block, SE);
+  }
+  return VisitCompoundStmt(SE->getSubStmt());
+}
+
+CFGBlock *CFGBuilder::VisitSwitchStmt(SwitchStmt *Terminator) {
+  // "switch" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  CFGBlock *SwitchSuccessor = NULL;
+
+  // Save local scope position because in case of condition variable ScopePos
+  // won't be restored when traversing AST.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scope for possible condition variable.
+  // Store scope position. Add implicit destructor.
+  if (VarDecl *VD = Terminator->getConditionVariable()) {
+    LocalScope::const_iterator SwitchBeginScopePos = ScopePos;
+    addLocalScopeForVarDecl(VD);
+    addAutomaticObjDtors(ScopePos, SwitchBeginScopePos, Terminator);
+  }
+
+  if (Block) {
+    if (badCFG)
+      return 0;
+    SwitchSuccessor = Block;
+  } else SwitchSuccessor = Succ;
+
+  // Save the current "switch" context.
+  SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock),
+                            save_default(DefaultCaseBlock);
+  SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
+
+  // Set the "default" case to be the block after the switch statement.  If the
+  // switch statement contains a "default:", this value will be overwritten with
+  // the block for that code.
+  DefaultCaseBlock = SwitchSuccessor;
+
+  // Create a new block that will contain the switch statement.
+  SwitchTerminatedBlock = createBlock(false);
+
+  // Now process the switch body.  The code after the switch is the implicit
+  // successor.
+  Succ = SwitchSuccessor;
+  BreakJumpTarget = JumpTarget(SwitchSuccessor, ScopePos);
+
+  // When visiting the body, the case statements should automatically get linked
+  // up to the switch.  We also don't keep a pointer to the body, since all
+  // control-flow from the switch goes to case/default statements.
+  assert(Terminator->getBody() && "switch must contain a non-NULL body");
+  Block = NULL;
+
+  // For pruning unreachable case statements, save the current state
+  // for tracking the condition value.
+  SaveAndRestore<bool> save_switchExclusivelyCovered(switchExclusivelyCovered,
+                                                     false);
+
+  // Determine if the switch condition can be explicitly evaluated.
+  assert(Terminator->getCond() && "switch condition must be non-NULL");
+  Expr::EvalResult result;
+  bool b = tryEvaluate(Terminator->getCond(), result);
+  SaveAndRestore<Expr::EvalResult*> save_switchCond(switchCond,
+                                                    b ? &result : 0);
+
+  // If body is not a compound statement create implicit scope
+  // and add destructors.
+  if (!isa<CompoundStmt>(Terminator->getBody()))
+    addLocalScopeAndDtors(Terminator->getBody());
+
+  addStmt(Terminator->getBody());
+  if (Block) {
+    if (badCFG)
+      return 0;
+  }
+
+  // If we have no "default:" case, the default transition is to the code
+  // following the switch body.  Moreover, take into account if all the
+  // cases of a switch are covered (e.g., switching on an enum value).
+  addSuccessor(SwitchTerminatedBlock,
+               switchExclusivelyCovered || Terminator->isAllEnumCasesCovered()
+               ? 0 : DefaultCaseBlock);
+
+  // Add the terminator and condition in the switch block.
+  SwitchTerminatedBlock->setTerminator(Terminator);
+  Block = SwitchTerminatedBlock;
+  Block = addStmt(Terminator->getCond());
+
+  // Finally, if the SwitchStmt contains a condition variable, add both the
+  // SwitchStmt and the condition variable initialization to the CFG.
+  if (VarDecl *VD = Terminator->getConditionVariable()) {
+    if (Expr *Init = VD->getInit()) {
+      autoCreateBlock();
+      appendStmt(Block, Terminator->getConditionVariableDeclStmt());
+      addStmt(Init);
+    }
+  }
+
+  return Block;
+}
+  
+static bool shouldAddCase(bool &switchExclusivelyCovered,
+                          const Expr::EvalResult *switchCond,
+                          const CaseStmt *CS,
+                          ASTContext &Ctx) {
+  if (!switchCond)
+    return true;
+
+  bool addCase = false;
+
+  if (!switchExclusivelyCovered) {
+    if (switchCond->Val.isInt()) {
+      // Evaluate the LHS of the case value.
+      const llvm::APSInt &lhsInt = CS->getLHS()->EvaluateKnownConstInt(Ctx);
+      const llvm::APSInt &condInt = switchCond->Val.getInt();
+      
+      if (condInt == lhsInt) {
+        addCase = true;
+        switchExclusivelyCovered = true;
+      }
+      else if (condInt < lhsInt) {
+        if (const Expr *RHS = CS->getRHS()) {
+          // Evaluate the RHS of the case value.
+          const llvm::APSInt &V2 = RHS->EvaluateKnownConstInt(Ctx);
+          if (V2 <= condInt) {
+            addCase = true;
+            switchExclusivelyCovered = true;
+          }
+        }
+      }
+    }
+    else
+      addCase = true;
+  }
+  return addCase;  
+}
+
+CFGBlock *CFGBuilder::VisitCaseStmt(CaseStmt *CS) {
+  // CaseStmts are essentially labels, so they are the first statement in a
+  // block.
+  CFGBlock *TopBlock = 0, *LastBlock = 0;
+
+  if (Stmt *Sub = CS->getSubStmt()) {
+    // For deeply nested chains of CaseStmts, instead of doing a recursion
+    // (which can blow out the stack), manually unroll and create blocks
+    // along the way.
+    while (isa<CaseStmt>(Sub)) {
+      CFGBlock *currentBlock = createBlock(false);
+      currentBlock->setLabel(CS);
+
+      if (TopBlock)
+        addSuccessor(LastBlock, currentBlock);
+      else
+        TopBlock = currentBlock;
+
+      addSuccessor(SwitchTerminatedBlock,
+                   shouldAddCase(switchExclusivelyCovered, switchCond,
+                                 CS, *Context)
+                   ? currentBlock : 0);
+
+      LastBlock = currentBlock;
+      CS = cast<CaseStmt>(Sub);
+      Sub = CS->getSubStmt();
+    }
+
+    addStmt(Sub);
+  }
+
+  CFGBlock *CaseBlock = Block;
+  if (!CaseBlock)
+    CaseBlock = createBlock();
+
+  // Cases statements partition blocks, so this is the top of the basic block we
+  // were processing (the "case XXX:" is the label).
+  CaseBlock->setLabel(CS);
+
+  if (badCFG)
+    return 0;
+
+  // Add this block to the list of successors for the block with the switch
+  // statement.
+  assert(SwitchTerminatedBlock);
+  addSuccessor(SwitchTerminatedBlock,
+               shouldAddCase(switchExclusivelyCovered, switchCond,
+                             CS, *Context)
+               ? CaseBlock : 0);
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary)
+  Block = NULL;
+
+  if (TopBlock) {
+    addSuccessor(LastBlock, CaseBlock);
+    Succ = TopBlock;
+  } else {
+    // This block is now the implicit successor of other blocks.
+    Succ = CaseBlock;
+  }
+
+  return Succ;
+}
+
+CFGBlock *CFGBuilder::VisitDefaultStmt(DefaultStmt *Terminator) {
+  if (Terminator->getSubStmt())
+    addStmt(Terminator->getSubStmt());
+
+  DefaultCaseBlock = Block;
+
+  if (!DefaultCaseBlock)
+    DefaultCaseBlock = createBlock();
+
+  // Default statements partition blocks, so this is the top of the basic block
+  // we were processing (the "default:" is the label).
+  DefaultCaseBlock->setLabel(Terminator);
+
+  if (badCFG)
+    return 0;
+
+  // Unlike case statements, we don't add the default block to the successors
+  // for the switch statement immediately.  This is done when we finish
+  // processing the switch statement.  This allows for the default case
+  // (including a fall-through to the code after the switch statement) to always
+  // be the last successor of a switch-terminated block.
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary)
+  Block = NULL;
+
+  // This block is now the implicit successor of other blocks.
+  Succ = DefaultCaseBlock;
+
+  return DefaultCaseBlock;
+}
+
+CFGBlock *CFGBuilder::VisitCXXTryStmt(CXXTryStmt *Terminator) {
+  // "try"/"catch" is a control-flow statement.  Thus we stop processing the
+  // current block.
+  CFGBlock *TrySuccessor = NULL;
+
+  if (Block) {
+    if (badCFG)
+      return 0;
+    TrySuccessor = Block;
+  } else TrySuccessor = Succ;
+
+  CFGBlock *PrevTryTerminatedBlock = TryTerminatedBlock;
+
+  // Create a new block that will contain the try statement.
+  CFGBlock *NewTryTerminatedBlock = createBlock(false);
+  // Add the terminator in the try block.
+  NewTryTerminatedBlock->setTerminator(Terminator);
+
+  bool HasCatchAll = false;
+  for (unsigned h = 0; h <Terminator->getNumHandlers(); ++h) {
+    // The code after the try is the implicit successor.
+    Succ = TrySuccessor;
+    CXXCatchStmt *CS = Terminator->getHandler(h);
+    if (CS->getExceptionDecl() == 0) {
+      HasCatchAll = true;
+    }
+    Block = NULL;
+    CFGBlock *CatchBlock = VisitCXXCatchStmt(CS);
+    if (CatchBlock == 0)
+      return 0;
+    // Add this block to the list of successors for the block with the try
+    // statement.
+    addSuccessor(NewTryTerminatedBlock, CatchBlock);
+  }
+  if (!HasCatchAll) {
+    if (PrevTryTerminatedBlock)
+      addSuccessor(NewTryTerminatedBlock, PrevTryTerminatedBlock);
+    else
+      addSuccessor(NewTryTerminatedBlock, &cfg->getExit());
+  }
+
+  // The code after the try is the implicit successor.
+  Succ = TrySuccessor;
+
+  // Save the current "try" context.
+  SaveAndRestore<CFGBlock*> save_try(TryTerminatedBlock, NewTryTerminatedBlock);
+  cfg->addTryDispatchBlock(TryTerminatedBlock);
+
+  assert(Terminator->getTryBlock() && "try must contain a non-NULL body");
+  Block = NULL;
+  Block = addStmt(Terminator->getTryBlock());
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt *CS) {
+  // CXXCatchStmt are treated like labels, so they are the first statement in a
+  // block.
+
+  // Save local scope position because in case of exception variable ScopePos
+  // won't be restored when traversing AST.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scope for possible exception variable.
+  // Store scope position. Add implicit destructor.
+  if (VarDecl *VD = CS->getExceptionDecl()) {
+    LocalScope::const_iterator BeginScopePos = ScopePos;
+    addLocalScopeForVarDecl(VD);
+    addAutomaticObjDtors(ScopePos, BeginScopePos, CS);
+  }
+
+  if (CS->getHandlerBlock())
+    addStmt(CS->getHandlerBlock());
+
+  CFGBlock *CatchBlock = Block;
+  if (!CatchBlock)
+    CatchBlock = createBlock();
+  
+  // CXXCatchStmt is more than just a label.  They have semantic meaning
+  // as well, as they implicitly "initialize" the catch variable.  Add
+  // it to the CFG as a CFGElement so that the control-flow of these
+  // semantics gets captured.
+  appendStmt(CatchBlock, CS);
+
+  // Also add the CXXCatchStmt as a label, to mirror handling of regular
+  // labels.
+  CatchBlock->setLabel(CS);
+
+  // Bail out if the CFG is bad.
+  if (badCFG)
+    return 0;
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary)
+  Block = NULL;
+
+  return CatchBlock;
+}
+
+CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
+  // C++0x for-range statements are specified as [stmt.ranged]:
+  //
+  // {
+  //   auto && __range = range-init;
+  //   for ( auto __begin = begin-expr,
+  //         __end = end-expr;
+  //         __begin != __end;
+  //         ++__begin ) {
+  //     for-range-declaration = *__begin;
+  //     statement
+  //   }
+  // }
+
+  // Save local scope position before the addition of the implicit variables.
+  SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+  // Create local scopes and destructors for range, begin and end variables.
+  if (Stmt *Range = S->getRangeStmt())
+    addLocalScopeForStmt(Range);
+  if (Stmt *BeginEnd = S->getBeginEndStmt())
+    addLocalScopeForStmt(BeginEnd);
+  addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S);
+
+  LocalScope::const_iterator ContinueScopePos = ScopePos;
+
+  // "for" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  CFGBlock *LoopSuccessor = NULL;
+  if (Block) {
+    if (badCFG)
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Save the current value for the break targets.
+  // All breaks should go to the code following the loop.
+  SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
+  BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+
+  // The block for the __begin != __end expression.
+  CFGBlock *ConditionBlock = createBlock(false);
+  ConditionBlock->setTerminator(S);
+
+  // Now add the actual condition to the condition block.
+  if (Expr *C = S->getCond()) {
+    Block = ConditionBlock;
+    CFGBlock *BeginConditionBlock = addStmt(C);
+    if (badCFG)
+      return 0;
+    assert(BeginConditionBlock == ConditionBlock &&
+           "condition block in for-range was unexpectedly complex");
+    (void)BeginConditionBlock;
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = ConditionBlock;
+
+  // See if this is a known constant.
+  TryResult KnownVal(true);
+
+  if (S->getCond())
+    KnownVal = tryEvaluateBool(S->getCond());
+
+  // Now create the loop body.
+  {
+    assert(S->getBody());
+
+    // Save the current values for Block, Succ, and continue targets.
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
+    SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
+
+    // Generate increment code in its own basic block.  This is the target of
+    // continue statements.
+    Block = 0;
+    Succ = addStmt(S->getInc());
+    ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
+
+    // The starting block for the loop increment is the block that should
+    // represent the 'loop target' for looping back to the start of the loop.
+    ContinueJumpTarget.block->setLoopTarget(S);
+
+    // Finish up the increment block and prepare to start the loop body.
+    assert(Block);
+    if (badCFG)
+      return 0;
+    Block = 0;
+
+
+    // Add implicit scope and dtors for loop variable.
+    addLocalScopeAndDtors(S->getLoopVarStmt());
+
+    // Populate a new block to contain the loop body and loop variable.
+    Block = addStmt(S->getBody());
+    if (badCFG)
+      return 0;
+    Block = addStmt(S->getLoopVarStmt());
+    if (badCFG)
+      return 0;
+    
+    // This new body block is a successor to our condition block.
+    addSuccessor(ConditionBlock, KnownVal.isFalse() ? 0 : Block);
+  }
+
+  // Link up the condition block with the code that follows the loop (the
+  // false branch).
+  addSuccessor(ConditionBlock, KnownVal.isTrue() ? 0 : LoopSuccessor);
+
+  // Add the initialization statements.
+  Block = createBlock();
+  addStmt(S->getBeginEndStmt());
+  return addStmt(S->getRangeStmt());
+}
+
+CFGBlock *CFGBuilder::VisitExprWithCleanups(ExprWithCleanups *E,
+    AddStmtChoice asc) {
+  if (BuildOpts.AddImplicitDtors) {
+    // If adding implicit destructors visit the full expression for adding
+    // destructors of temporaries.
+    VisitForTemporaryDtors(E->getSubExpr());
+
+    // Full expression has to be added as CFGStmt so it will be sequenced
+    // before destructors of it's temporaries.
+    asc = asc.withAlwaysAdd(true);
+  }
+  return Visit(E->getSubExpr(), asc);
+}
+
+CFGBlock *CFGBuilder::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
+                                                AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, E)) {
+    autoCreateBlock();
+    appendStmt(Block, E);
+
+    // We do not want to propagate the AlwaysAdd property.
+    asc = asc.withAlwaysAdd(false);
+  }
+  return Visit(E->getSubExpr(), asc);
+}
+
+CFGBlock *CFGBuilder::VisitCXXConstructExpr(CXXConstructExpr *C,
+                                            AddStmtChoice asc) {
+  autoCreateBlock();
+  appendStmt(Block, C);
+
+  return VisitChildren(C);
+}
+
+CFGBlock *CFGBuilder::VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E,
+                                                 AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, E)) {
+    autoCreateBlock();
+    appendStmt(Block, E);
+    // We do not want to propagate the AlwaysAdd property.
+    asc = asc.withAlwaysAdd(false);
+  }
+  return Visit(E->getSubExpr(), asc);
+}
+
+CFGBlock *CFGBuilder::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *C,
+                                                  AddStmtChoice asc) {
+  autoCreateBlock();
+  appendStmt(Block, C);
+  return VisitChildren(C);
+}
+
+CFGBlock *CFGBuilder::VisitImplicitCastExpr(ImplicitCastExpr *E,
+                                            AddStmtChoice asc) {
+  if (asc.alwaysAdd(*this, E)) {
+    autoCreateBlock();
+    appendStmt(Block, E);
+  }
+  return Visit(E->getSubExpr(), AddStmtChoice());
+}
+
+CFGBlock *CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt *I) {
+  // Lazily create the indirect-goto dispatch block if there isn't one already.
+  CFGBlock *IBlock = cfg->getIndirectGotoBlock();
+
+  if (!IBlock) {
+    IBlock = createBlock(false);
+    cfg->setIndirectGotoBlock(IBlock);
+  }
+
+  // IndirectGoto is a control-flow statement.  Thus we stop processing the
+  // current block and create a new one.
+  if (badCFG)
+    return 0;
+
+  Block = createBlock(false);
+  Block->setTerminator(I);
+  addSuccessor(Block, IBlock);
+  return addStmt(I->getTarget());
+}
+
+CFGBlock *CFGBuilder::VisitForTemporaryDtors(Stmt *E, bool BindToTemporary) {
+tryAgain:
+  if (!E) {
+    badCFG = true;
+    return NULL;
+  }
+  switch (E->getStmtClass()) {
+    default:
+      return VisitChildrenForTemporaryDtors(E);
+
+    case Stmt::BinaryOperatorClass:
+      return VisitBinaryOperatorForTemporaryDtors(cast<BinaryOperator>(E));
+
+    case Stmt::CXXBindTemporaryExprClass:
+      return VisitCXXBindTemporaryExprForTemporaryDtors(
+          cast<CXXBindTemporaryExpr>(E), BindToTemporary);
+
+    case Stmt::BinaryConditionalOperatorClass:
+    case Stmt::ConditionalOperatorClass:
+      return VisitConditionalOperatorForTemporaryDtors(
+          cast<AbstractConditionalOperator>(E), BindToTemporary);
+
+    case Stmt::ImplicitCastExprClass:
+      // For implicit cast we want BindToTemporary to be passed further.
+      E = cast<CastExpr>(E)->getSubExpr();
+      goto tryAgain;
+
+    case Stmt::ParenExprClass:
+      E = cast<ParenExpr>(E)->getSubExpr();
+      goto tryAgain;
+      
+    case Stmt::MaterializeTemporaryExprClass:
+      E = cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr();
+      goto tryAgain;
+  }
+}
+
+CFGBlock *CFGBuilder::VisitChildrenForTemporaryDtors(Stmt *E) {
+  // When visiting children for destructors we want to visit them in reverse
+  // order. Because there's no reverse iterator for children must to reverse
+  // them in helper vector.
+  typedef SmallVector<Stmt *, 4> ChildrenVect;
+  ChildrenVect ChildrenRev;
+  for (Stmt::child_range I = E->children(); I; ++I) {
+    if (*I) ChildrenRev.push_back(*I);
+  }
+
+  CFGBlock *B = Block;
+  for (ChildrenVect::reverse_iterator I = ChildrenRev.rbegin(),
+      L = ChildrenRev.rend(); I != L; ++I) {
+    if (CFGBlock *R = VisitForTemporaryDtors(*I))
+      B = R;
+  }
+  return B;
+}
+
+CFGBlock *CFGBuilder::VisitBinaryOperatorForTemporaryDtors(BinaryOperator *E) {
+  if (E->isLogicalOp()) {
+    // Destructors for temporaries in LHS expression should be called after
+    // those for RHS expression. Even if this will unnecessarily create a block,
+    // this block will be used at least by the full expression.
+    autoCreateBlock();
+    CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getLHS());
+    if (badCFG)
+      return NULL;
+
+    Succ = ConfluenceBlock;
+    Block = NULL;
+    CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
+
+    if (RHSBlock) {
+      if (badCFG)
+        return NULL;
+
+      // If RHS expression did produce destructors we need to connect created
+      // blocks to CFG in same manner as for binary operator itself.
+      CFGBlock *LHSBlock = createBlock(false);
+      LHSBlock->setTerminator(CFGTerminator(E, true));
+
+      // For binary operator LHS block is before RHS in list of predecessors
+      // of ConfluenceBlock.
+      std::reverse(ConfluenceBlock->pred_begin(),
+          ConfluenceBlock->pred_end());
+
+      // See if this is a known constant.
+      TryResult KnownVal = tryEvaluateBool(E->getLHS());
+      if (KnownVal.isKnown() && (E->getOpcode() == BO_LOr))
+        KnownVal.negate();
+
+      // Link LHSBlock with RHSBlock exactly the same way as for binary operator
+      // itself.
+      if (E->getOpcode() == BO_LOr) {
+        addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+        addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+      } else {
+        assert (E->getOpcode() == BO_LAnd);
+        addSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+        addSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+      }
+
+      Block = LHSBlock;
+      return LHSBlock;
+    }
+
+    Block = ConfluenceBlock;
+    return ConfluenceBlock;
+  }
+
+  if (E->isAssignmentOp()) {
+    // For assignment operator (=) LHS expression is visited
+    // before RHS expression. For destructors visit them in reverse order.
+    CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
+    CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
+    return LHSBlock ? LHSBlock : RHSBlock;
+  }
+
+  // For any other binary operator RHS expression is visited before
+  // LHS expression (order of children). For destructors visit them in reverse
+  // order.
+  CFGBlock *LHSBlock = VisitForTemporaryDtors(E->getLHS());
+  CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getRHS());
+  return RHSBlock ? RHSBlock : LHSBlock;
+}
+
+CFGBlock *CFGBuilder::VisitCXXBindTemporaryExprForTemporaryDtors(
+    CXXBindTemporaryExpr *E, bool BindToTemporary) {
+  // First add destructors for temporaries in subexpression.
+  CFGBlock *B = VisitForTemporaryDtors(E->getSubExpr());
+  if (!BindToTemporary) {
+    // If lifetime of temporary is not prolonged (by assigning to constant
+    // reference) add destructor for it.
+
+    // If the destructor is marked as a no-return destructor, we need to create
+    // a new block for the destructor which does not have as a successor
+    // anything built thus far. Control won't flow out of this block.
+    const CXXDestructorDecl *Dtor = E->getTemporary()->getDestructor();
+    if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
+      Block = createNoReturnBlock();
+    else
+      autoCreateBlock();
+
+    appendTemporaryDtor(Block, E);
+    B = Block;
+  }
+  return B;
+}
+
+CFGBlock *CFGBuilder::VisitConditionalOperatorForTemporaryDtors(
+    AbstractConditionalOperator *E, bool BindToTemporary) {
+  // First add destructors for condition expression.  Even if this will
+  // unnecessarily create a block, this block will be used at least by the full
+  // expression.
+  autoCreateBlock();
+  CFGBlock *ConfluenceBlock = VisitForTemporaryDtors(E->getCond());
+  if (badCFG)
+    return NULL;
+  if (BinaryConditionalOperator *BCO
+        = dyn_cast<BinaryConditionalOperator>(E)) {
+    ConfluenceBlock = VisitForTemporaryDtors(BCO->getCommon());
+    if (badCFG)
+      return NULL;
+  }
+
+  // Try to add block with destructors for LHS expression.
+  CFGBlock *LHSBlock = NULL;
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  LHSBlock = VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary);
+  if (badCFG)
+    return NULL;
+
+  // Try to add block with destructors for RHS expression;
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock *RHSBlock = VisitForTemporaryDtors(E->getFalseExpr(),
+                                              BindToTemporary);
+  if (badCFG)
+    return NULL;
+
+  if (!RHSBlock && !LHSBlock) {
+    // If neither LHS nor RHS expression had temporaries to destroy don't create
+    // more blocks.
+    Block = ConfluenceBlock;
+    return Block;
+  }
+
+  Block = createBlock(false);
+  Block->setTerminator(CFGTerminator(E, true));
+
+  // See if this is a known constant.
+  const TryResult &KnownVal = tryEvaluateBool(E->getCond());
+
+  if (LHSBlock) {
+    addSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+  } else if (KnownVal.isFalse()) {
+    addSuccessor(Block, NULL);
+  } else {
+    addSuccessor(Block, ConfluenceBlock);
+    std::reverse(ConfluenceBlock->pred_begin(), ConfluenceBlock->pred_end());
+  }
+
+  if (!RHSBlock)
+    RHSBlock = ConfluenceBlock;
+  addSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+
+  return Block;
+}
+
+} // end anonymous namespace
+
+/// createBlock - Constructs and adds a new CFGBlock to the CFG.  The block has
+///  no successors or predecessors.  If this is the first block created in the
+///  CFG, it is automatically set to be the Entry and Exit of the CFG.
+CFGBlock *CFG::createBlock() {
+  bool first_block = begin() == end();
+
+  // Create the block.
+  CFGBlock *Mem = getAllocator().Allocate<CFGBlock>();
+  new (Mem) CFGBlock(NumBlockIDs++, BlkBVC, this);
+  Blocks.push_back(Mem, BlkBVC);
+
+  // If this is the first block, set it as the Entry and Exit.
+  if (first_block)
+    Entry = Exit = &back();
+
+  // Return the block.
+  return &back();
+}
+
+/// buildCFG - Constructs a CFG from an AST.  Ownership of the returned
+///  CFG is returned to the caller.
+CFG* CFG::buildCFG(const Decl *D, Stmt *Statement, ASTContext *C,
+    const BuildOptions &BO) {
+  CFGBuilder Builder(C, BO);
+  return Builder.buildCFG(D, Statement);
+}
+
+const CXXDestructorDecl *
+CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
+  switch (getKind()) {
+    case CFGElement::Invalid:
+    case CFGElement::Statement:
+    case CFGElement::Initializer:
+      llvm_unreachable("getDestructorDecl should only be used with "
+                       "ImplicitDtors");
+    case CFGElement::AutomaticObjectDtor: {
+      const VarDecl *var = cast<CFGAutomaticObjDtor>(this)->getVarDecl();
+      QualType ty = var->getType();
+      ty = ty.getNonReferenceType();
+      while (const ArrayType *arrayType = astContext.getAsArrayType(ty)) {
+        ty = arrayType->getElementType();
+      }
+      const RecordType *recordType = ty->getAs<RecordType>();
+      const CXXRecordDecl *classDecl =
+      cast<CXXRecordDecl>(recordType->getDecl());
+      return classDecl->getDestructor();      
+    }
+    case CFGElement::TemporaryDtor: {
+      const CXXBindTemporaryExpr *bindExpr =
+        cast<CFGTemporaryDtor>(this)->getBindTemporaryExpr();
+      const CXXTemporary *temp = bindExpr->getTemporary();
+      return temp->getDestructor();
+    }
+    case CFGElement::BaseDtor:
+    case CFGElement::MemberDtor:
+
+      // Not yet supported.
+      return 0;
+  }
+  llvm_unreachable("getKind() returned bogus value");
+}
+
+bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const {
+  if (const CXXDestructorDecl *cdecl = getDestructorDecl(astContext)) {
+    QualType ty = cdecl->getType();
+    return cast<FunctionType>(ty)->getNoReturnAttr();
+  }
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// CFG: Queries for BlkExprs.
+//===----------------------------------------------------------------------===//
+
+namespace {
+  typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy;
+}
+
+static void FindSubExprAssignments(const Stmt *S,
+                                   llvm::SmallPtrSet<const Expr*,50>& Set) {
+  if (!S)
+    return;
+
+  for (Stmt::const_child_range I = S->children(); I; ++I) {
+    const Stmt *child = *I;
+    if (!child)
+      continue;
+
+    if (const BinaryOperator* B = dyn_cast<BinaryOperator>(child))
+      if (B->isAssignmentOp()) Set.insert(B);
+
+    FindSubExprAssignments(child, Set);
+  }
+}
+
+static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) {
+  BlkExprMapTy* M = new BlkExprMapTy();
+
+  // Look for assignments that are used as subexpressions.  These are the only
+  // assignments that we want to *possibly* register as a block-level
+  // expression.  Basically, if an assignment occurs both in a subexpression and
+  // at the block-level, it is a block-level expression.
+  llvm::SmallPtrSet<const Expr*,50> SubExprAssignments;
+
+  for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I)
+    for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
+      if (const CFGStmt *S = BI->getAs<CFGStmt>())
+        FindSubExprAssignments(S->getStmt(), SubExprAssignments);
+
+  for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) {
+
+    // Iterate over the statements again on identify the Expr* and Stmt* at the
+    // block-level that are block-level expressions.
+
+    for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI) {
+      const CFGStmt *CS = BI->getAs<CFGStmt>();
+      if (!CS)
+        continue;
+      if (const Expr *Exp = dyn_cast<Expr>(CS->getStmt())) {
+        assert((Exp->IgnoreParens() == Exp) && "No parens on block-level exps");
+
+        if (const BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) {
+          // Assignment expressions that are not nested within another
+          // expression are really "statements" whose value is never used by
+          // another expression.
+          if (B->isAssignmentOp() && !SubExprAssignments.count(Exp))
+            continue;
+        } else if (const StmtExpr *SE = dyn_cast<StmtExpr>(Exp)) {
+          // Special handling for statement expressions.  The last statement in
+          // the statement expression is also a block-level expr.
+          const CompoundStmt *C = SE->getSubStmt();
+          if (!C->body_empty()) {
+            const Stmt *Last = C->body_back();
+            if (const Expr *LastEx = dyn_cast<Expr>(Last))
+              Last = LastEx->IgnoreParens();
+            unsigned x = M->size();
+            (*M)[Last] = x;
+          }
+        }
+
+        unsigned x = M->size();
+        (*M)[Exp] = x;
+      }
+    }
+
+    // Look at terminators.  The condition is a block-level expression.
+
+    Stmt *S = (*I)->getTerminatorCondition();
+
+    if (S && M->find(S) == M->end()) {
+      unsigned x = M->size();
+      (*M)[S] = x;
+    }
+  }
+
+  return M;
+}
+
+CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt *S) {
+  assert(S != NULL);
+  if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); }
+
+  BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap);
+  BlkExprMapTy::iterator I = M->find(S);
+  return (I == M->end()) ? CFG::BlkExprNumTy() : CFG::BlkExprNumTy(I->second);
+}
+
+unsigned CFG::getNumBlkExprs() {
+  if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap))
+    return M->size();
+
+  // We assume callers interested in the number of BlkExprs will want
+  // the map constructed if it doesn't already exist.
+  BlkExprMap = (void*) PopulateBlkExprMap(*this);
+  return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size();
+}
+
+//===----------------------------------------------------------------------===//
+// Filtered walking of the CFG.
+//===----------------------------------------------------------------------===//
+
+bool CFGBlock::FilterEdge(const CFGBlock::FilterOptions &F,
+        const CFGBlock *From, const CFGBlock *To) {
+
+  if (To && F.IgnoreDefaultsWithCoveredEnums) {
+    // If the 'To' has no label or is labeled but the label isn't a
+    // CaseStmt then filter this edge.
+    if (const SwitchStmt *S =
+        dyn_cast_or_null<SwitchStmt>(From->getTerminator().getStmt())) {
+      if (S->isAllEnumCasesCovered()) {
+        const Stmt *L = To->getLabel();
+        if (!L || !isa<CaseStmt>(L))
+          return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// Cleanup: CFG dstor.
+//===----------------------------------------------------------------------===//
+
+CFG::~CFG() {
+  delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap);
+}
+
+//===----------------------------------------------------------------------===//
+// CFG pretty printing
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class StmtPrinterHelper : public PrinterHelper  {
+  typedef llvm::DenseMap<const Stmt*,std::pair<unsigned,unsigned> > StmtMapTy;
+  typedef llvm::DenseMap<const Decl*,std::pair<unsigned,unsigned> > DeclMapTy;
+  StmtMapTy StmtMap;
+  DeclMapTy DeclMap;
+  signed currentBlock;
+  unsigned currentStmt;
+  const LangOptions &LangOpts;
+public:
+
+  StmtPrinterHelper(const CFG* cfg, const LangOptions &LO)
+    : currentBlock(0), currentStmt(0), LangOpts(LO)
+  {
+    for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) {
+      unsigned j = 1;
+      for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ;
+           BI != BEnd; ++BI, ++j ) {        
+        if (const CFGStmt *SE = BI->getAs<CFGStmt>()) {
+          const Stmt *stmt= SE->getStmt();
+          std::pair<unsigned, unsigned> P((*I)->getBlockID(), j);
+          StmtMap[stmt] = P;
+
+          switch (stmt->getStmtClass()) {
+            case Stmt::DeclStmtClass:
+                DeclMap[cast<DeclStmt>(stmt)->getSingleDecl()] = P;
+                break;
+            case Stmt::IfStmtClass: {
+              const VarDecl *var = cast<IfStmt>(stmt)->getConditionVariable();
+              if (var)
+                DeclMap[var] = P;
+              break;
+            }
+            case Stmt::ForStmtClass: {
+              const VarDecl *var = cast<ForStmt>(stmt)->getConditionVariable();
+              if (var)
+                DeclMap[var] = P;
+              break;
+            }
+            case Stmt::WhileStmtClass: {
+              const VarDecl *var =
+                cast<WhileStmt>(stmt)->getConditionVariable();
+              if (var)
+                DeclMap[var] = P;
+              break;
+            }
+            case Stmt::SwitchStmtClass: {
+              const VarDecl *var =
+                cast<SwitchStmt>(stmt)->getConditionVariable();
+              if (var)
+                DeclMap[var] = P;
+              break;
+            }
+            case Stmt::CXXCatchStmtClass: {
+              const VarDecl *var =
+                cast<CXXCatchStmt>(stmt)->getExceptionDecl();
+              if (var)
+                DeclMap[var] = P;
+              break;
+            }
+            default:
+              break;
+          }
+        }
+      }
+    }
+  }
+  
+
+  virtual ~StmtPrinterHelper() {}
+
+  const LangOptions &getLangOpts() const { return LangOpts; }
+  void setBlockID(signed i) { currentBlock = i; }
+  void setStmtID(unsigned i) { currentStmt = i; }
+
+  virtual bool handledStmt(Stmt *S, raw_ostream &OS) {
+    StmtMapTy::iterator I = StmtMap.find(S);
+
+    if (I == StmtMap.end())
+      return false;
+
+    if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
+                          && I->second.second == currentStmt) {
+      return false;
+    }
+
+    OS << "[B" << I->second.first << "." << I->second.second << "]";
+    return true;
+  }
+
+  bool handleDecl(const Decl *D, raw_ostream &OS) {
+    DeclMapTy::iterator I = DeclMap.find(D);
+
+    if (I == DeclMap.end())
+      return false;
+
+    if (currentBlock >= 0 && I->second.first == (unsigned) currentBlock
+                          && I->second.second == currentStmt) {
+      return false;
+    }
+
+    OS << "[B" << I->second.first << "." << I->second.second << "]";
+    return true;
+  }
+};
+} // end anonymous namespace
+
+
+namespace {
+class CFGBlockTerminatorPrint
+  : public StmtVisitor<CFGBlockTerminatorPrint,void> {
+
+  raw_ostream &OS;
+  StmtPrinterHelper* Helper;
+  PrintingPolicy Policy;
+public:
+  CFGBlockTerminatorPrint(raw_ostream &os, StmtPrinterHelper* helper,
+                          const PrintingPolicy &Policy)
+    : OS(os), Helper(helper), Policy(Policy) {}
+
+  void VisitIfStmt(IfStmt *I) {
+    OS << "if ";
+    I->getCond()->printPretty(OS,Helper,Policy);
+  }
+
+  // Default case.
+  void VisitStmt(Stmt *Terminator) {
+    Terminator->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitForStmt(ForStmt *F) {
+    OS << "for (" ;
+    if (F->getInit())
+      OS << "...";
+    OS << "; ";
+    if (Stmt *C = F->getCond())
+      C->printPretty(OS, Helper, Policy);
+    OS << "; ";
+    if (F->getInc())
+      OS << "...";
+    OS << ")";
+  }
+
+  void VisitWhileStmt(WhileStmt *W) {
+    OS << "while " ;
+    if (Stmt *C = W->getCond())
+      C->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitDoStmt(DoStmt *D) {
+    OS << "do ... while ";
+    if (Stmt *C = D->getCond())
+      C->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitSwitchStmt(SwitchStmt *Terminator) {
+    OS << "switch ";
+    Terminator->getCond()->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitCXXTryStmt(CXXTryStmt *CS) {
+    OS << "try ...";
+  }
+
+  void VisitAbstractConditionalOperator(AbstractConditionalOperator* C) {
+    C->getCond()->printPretty(OS, Helper, Policy);
+    OS << " ? ... : ...";
+  }
+
+  void VisitChooseExpr(ChooseExpr *C) {
+    OS << "__builtin_choose_expr( ";
+    C->getCond()->printPretty(OS, Helper, Policy);
+    OS << " )";
+  }
+
+  void VisitIndirectGotoStmt(IndirectGotoStmt *I) {
+    OS << "goto *";
+    I->getTarget()->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitBinaryOperator(BinaryOperator* B) {
+    if (!B->isLogicalOp()) {
+      VisitExpr(B);
+      return;
+    }
+
+    B->getLHS()->printPretty(OS, Helper, Policy);
+
+    switch (B->getOpcode()) {
+      case BO_LOr:
+        OS << " || ...";
+        return;
+      case BO_LAnd:
+        OS << " && ...";
+        return;
+      default:
+        llvm_unreachable("Invalid logical operator.");
+    }
+  }
+
+  void VisitExpr(Expr *E) {
+    E->printPretty(OS, Helper, Policy);
+  }
+};
+} // end anonymous namespace
+
+static void print_elem(raw_ostream &OS, StmtPrinterHelper* Helper,
+                       const CFGElement &E) {
+  if (const CFGStmt *CS = E.getAs<CFGStmt>()) {
+    const Stmt *S = CS->getStmt();
+    
+    if (Helper) {
+
+      // special printing for statement-expressions.
+      if (const StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
+        const CompoundStmt *Sub = SE->getSubStmt();
+
+        if (Sub->children()) {
+          OS << "({ ... ; ";
+          Helper->handledStmt(*SE->getSubStmt()->body_rbegin(),OS);
+          OS << " })\n";
+          return;
+        }
+      }
+      // special printing for comma expressions.
+      if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) {
+        if (B->getOpcode() == BO_Comma) {
+          OS << "... , ";
+          Helper->handledStmt(B->getRHS(),OS);
+          OS << '\n';
+          return;
+        }
+      }
+    }
+    S->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
+
+    if (isa<CXXOperatorCallExpr>(S)) {
+      OS << " (OperatorCall)";
+    }
+    else if (isa<CXXBindTemporaryExpr>(S)) {
+      OS << " (BindTemporary)";
+    }
+    else if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(S)) {
+      OS << " (CXXConstructExpr, " << CCE->getType().getAsString() << ")";
+    }
+    else if (const CastExpr *CE = dyn_cast<CastExpr>(S)) {
+      OS << " (" << CE->getStmtClassName() << ", "
+         << CE->getCastKindName()
+         << ", " << CE->getType().getAsString()
+         << ")";
+    }
+
+    // Expressions need a newline.
+    if (isa<Expr>(S))
+      OS << '\n';
+
+  } else if (const CFGInitializer *IE = E.getAs<CFGInitializer>()) {
+    const CXXCtorInitializer *I = IE->getInitializer();
+    if (I->isBaseInitializer())
+      OS << I->getBaseClass()->getAsCXXRecordDecl()->getName();
+    else OS << I->getAnyMember()->getName();
+
+    OS << "(";
+    if (Expr *IE = I->getInit())
+      IE->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
+    OS << ")";
+
+    if (I->isBaseInitializer())
+      OS << " (Base initializer)\n";
+    else OS << " (Member initializer)\n";
+
+  } else if (const CFGAutomaticObjDtor *DE = E.getAs<CFGAutomaticObjDtor>()){
+    const VarDecl *VD = DE->getVarDecl();
+    Helper->handleDecl(VD, OS);
+
+    const Type* T = VD->getType().getTypePtr();
+    if (const ReferenceType* RT = T->getAs<ReferenceType>())
+      T = RT->getPointeeType().getTypePtr();
+    else if (const Type *ET = T->getArrayElementTypeNoTypeQual())
+      T = ET;
+
+    OS << ".~" << T->getAsCXXRecordDecl()->getName().str() << "()";
+    OS << " (Implicit destructor)\n";
+
+  } else if (const CFGBaseDtor *BE = E.getAs<CFGBaseDtor>()) {
+    const CXXBaseSpecifier *BS = BE->getBaseSpecifier();
+    OS << "~" << BS->getType()->getAsCXXRecordDecl()->getName() << "()";
+    OS << " (Base object destructor)\n";
+
+  } else if (const CFGMemberDtor *ME = E.getAs<CFGMemberDtor>()) {
+    const FieldDecl *FD = ME->getFieldDecl();
+
+    const Type *T = FD->getType().getTypePtr();
+    if (const Type *ET = T->getArrayElementTypeNoTypeQual())
+      T = ET;
+
+    OS << "this->" << FD->getName();
+    OS << ".~" << T->getAsCXXRecordDecl()->getName() << "()";
+    OS << " (Member object destructor)\n";
+
+  } else if (const CFGTemporaryDtor *TE = E.getAs<CFGTemporaryDtor>()) {
+    const CXXBindTemporaryExpr *BT = TE->getBindTemporaryExpr();
+    OS << "~" << BT->getType()->getAsCXXRecordDecl()->getName() << "()";
+    OS << " (Temporary object destructor)\n";
+  }
+}
+
+static void print_block(raw_ostream &OS, const CFG* cfg,
+                        const CFGBlock &B,
+                        StmtPrinterHelper* Helper, bool print_edges,
+                        bool ShowColors) {
+
+  if (Helper)
+    Helper->setBlockID(B.getBlockID());
+
+  // Print the header.
+  if (ShowColors)
+    OS.changeColor(raw_ostream::YELLOW, true);
+  
+  OS << "\n [B" << B.getBlockID();
+
+  if (&B == &cfg->getEntry())
+    OS << " (ENTRY)]\n";
+  else if (&B == &cfg->getExit())
+    OS << " (EXIT)]\n";
+  else if (&B == cfg->getIndirectGotoBlock())
+    OS << " (INDIRECT GOTO DISPATCH)]\n";
+  else
+    OS << "]\n";
+  
+  if (ShowColors)
+    OS.resetColor();
+
+  // Print the label of this block.
+  if (Stmt *Label = const_cast<Stmt*>(B.getLabel())) {
+
+    if (print_edges)
+      OS << "  ";
+
+    if (LabelStmt *L = dyn_cast<LabelStmt>(Label))
+      OS << L->getName();
+    else if (CaseStmt *C = dyn_cast<CaseStmt>(Label)) {
+      OS << "case ";
+      C->getLHS()->printPretty(OS, Helper,
+                               PrintingPolicy(Helper->getLangOpts()));
+      if (C->getRHS()) {
+        OS << " ... ";
+        C->getRHS()->printPretty(OS, Helper,
+                                 PrintingPolicy(Helper->getLangOpts()));
+      }
+    } else if (isa<DefaultStmt>(Label))
+      OS << "default";
+    else if (CXXCatchStmt *CS = dyn_cast<CXXCatchStmt>(Label)) {
+      OS << "catch (";
+      if (CS->getExceptionDecl())
+        CS->getExceptionDecl()->print(OS, PrintingPolicy(Helper->getLangOpts()),
+                                      0);
+      else
+        OS << "...";
+      OS << ")";
+
+    } else
+      llvm_unreachable("Invalid label statement in CFGBlock.");
+
+    OS << ":\n";
+  }
+
+  // Iterate through the statements in the block and print them.
+  unsigned j = 1;
+
+  for (CFGBlock::const_iterator I = B.begin(), E = B.end() ;
+       I != E ; ++I, ++j ) {
+
+    // Print the statement # in the basic block and the statement itself.
+    if (print_edges)
+      OS << " ";
+
+    OS << llvm::format("%3d", j) << ": ";
+
+    if (Helper)
+      Helper->setStmtID(j);
+
+    print_elem(OS, Helper, *I);
+  }
+
+  // Print the terminator of this block.
+  if (B.getTerminator()) {
+    if (ShowColors)
+      OS.changeColor(raw_ostream::GREEN);
+
+    OS << "   T: ";
+
+    if (Helper) Helper->setBlockID(-1);
+
+    CFGBlockTerminatorPrint TPrinter(OS, Helper,
+                                     PrintingPolicy(Helper->getLangOpts()));
+    TPrinter.Visit(const_cast<Stmt*>(B.getTerminator().getStmt()));
+    OS << '\n';
+    
+    if (ShowColors)
+      OS.resetColor();
+  }
+
+  if (print_edges) {
+    // Print the predecessors of this block.
+    if (!B.pred_empty()) {
+      const raw_ostream::Colors Color = raw_ostream::BLUE;
+      if (ShowColors)
+        OS.changeColor(Color);
+      OS << "   Preds " ;
+      if (ShowColors)
+        OS.resetColor();
+      OS << '(' << B.pred_size() << "):";
+      unsigned i = 0;
+
+      if (ShowColors)
+        OS.changeColor(Color);
+      
+      for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end();
+           I != E; ++I, ++i) {
+
+        if (i == 8 || (i-8) == 0)
+          OS << "\n     ";
+
+        OS << " B" << (*I)->getBlockID();
+      }
+      
+      if (ShowColors)
+        OS.resetColor();
+
+      OS << '\n';
+    }
+
+    // Print the successors of this block.
+    if (!B.succ_empty()) {
+      const raw_ostream::Colors Color = raw_ostream::MAGENTA;
+      if (ShowColors)
+        OS.changeColor(Color);
+      OS << "   Succs ";
+      if (ShowColors)
+        OS.resetColor();
+      OS << '(' << B.succ_size() << "):";
+      unsigned i = 0;
+
+      if (ShowColors)
+        OS.changeColor(Color);
+
+      for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end();
+           I != E; ++I, ++i) {
+
+        if (i == 8 || (i-8) % 10 == 0)
+          OS << "\n    ";
+
+        if (*I)
+          OS << " B" << (*I)->getBlockID();
+        else
+          OS  << " NULL";
+      }
+      
+      if (ShowColors)
+        OS.resetColor();
+      OS << '\n';
+    }
+  }
+}
+
+
+/// dump - A simple pretty printer of a CFG that outputs to stderr.
+void CFG::dump(const LangOptions &LO, bool ShowColors) const {
+  print(llvm::errs(), LO, ShowColors);
+}
+
+/// print - A simple pretty printer of a CFG that outputs to an ostream.
+void CFG::print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const {
+  StmtPrinterHelper Helper(this, LO);
+
+  // Print the entry block.
+  print_block(OS, this, getEntry(), &Helper, true, ShowColors);
+
+  // Iterate through the CFGBlocks and print them one by one.
+  for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) {
+    // Skip the entry block, because we already printed it.
+    if (&(**I) == &getEntry() || &(**I) == &getExit())
+      continue;
+
+    print_block(OS, this, **I, &Helper, true, ShowColors);
+  }
+
+  // Print the exit block.
+  print_block(OS, this, getExit(), &Helper, true, ShowColors);
+  OS << '\n';
+  OS.flush();
+}
+
+/// dump - A simply pretty printer of a CFGBlock that outputs to stderr.
+void CFGBlock::dump(const CFG* cfg, const LangOptions &LO,
+                    bool ShowColors) const {
+  print(llvm::errs(), cfg, LO, ShowColors);
+}
+
+/// print - A simple pretty printer of a CFGBlock that outputs to an ostream.
+///   Generally this will only be called from CFG::print.
+void CFGBlock::print(raw_ostream &OS, const CFG* cfg,
+                     const LangOptions &LO, bool ShowColors) const {
+  StmtPrinterHelper Helper(cfg, LO);
+  print_block(OS, cfg, *this, &Helper, true, ShowColors);
+  OS << '\n';
+}
+
+/// printTerminator - A simple pretty printer of the terminator of a CFGBlock.
+void CFGBlock::printTerminator(raw_ostream &OS,
+                               const LangOptions &LO) const {
+  CFGBlockTerminatorPrint TPrinter(OS, NULL, PrintingPolicy(LO));
+  TPrinter.Visit(const_cast<Stmt*>(getTerminator().getStmt()));
+}
+
+Stmt *CFGBlock::getTerminatorCondition() {
+  Stmt *Terminator = this->Terminator;
+  if (!Terminator)
+    return NULL;
+
+  Expr *E = NULL;
+
+  switch (Terminator->getStmtClass()) {
+    default:
+      break;
+
+    case Stmt::ForStmtClass:
+      E = cast<ForStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::WhileStmtClass:
+      E = cast<WhileStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::DoStmtClass:
+      E = cast<DoStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::IfStmtClass:
+      E = cast<IfStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::ChooseExprClass:
+      E = cast<ChooseExpr>(Terminator)->getCond();
+      break;
+
+    case Stmt::IndirectGotoStmtClass:
+      E = cast<IndirectGotoStmt>(Terminator)->getTarget();
+      break;
+
+    case Stmt::SwitchStmtClass:
+      E = cast<SwitchStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::BinaryConditionalOperatorClass:
+      E = cast<BinaryConditionalOperator>(Terminator)->getCond();
+      break;
+
+    case Stmt::ConditionalOperatorClass:
+      E = cast<ConditionalOperator>(Terminator)->getCond();
+      break;
+
+    case Stmt::BinaryOperatorClass: // '&&' and '||'
+      E = cast<BinaryOperator>(Terminator)->getLHS();
+      break;
+
+    case Stmt::ObjCForCollectionStmtClass:
+      return Terminator;
+  }
+
+  return E ? E->IgnoreParens() : NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// CFG Graphviz Visualization
+//===----------------------------------------------------------------------===//
+
+
+#ifndef NDEBUG
+static StmtPrinterHelper* GraphHelper;
+#endif
+
+void CFG::viewCFG(const LangOptions &LO) const {
+#ifndef NDEBUG
+  StmtPrinterHelper H(this, LO);
+  GraphHelper = &H;
+  llvm::ViewGraph(this,"CFG");
+  GraphHelper = NULL;
+#endif
+}
+
+namespace llvm {
+template<>
+struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+
+  static std::string getNodeLabel(const CFGBlock *Node, const CFG* Graph) {
+
+#ifndef NDEBUG
+    std::string OutSStr;
+    llvm::raw_string_ostream Out(OutSStr);
+    print_block(Out,Graph, *Node, GraphHelper, false, false);
+    std::string& OutStr = Out.str();
+
+    if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
+
+    // Process string output to make it nicer...
+    for (unsigned i = 0; i != OutStr.length(); ++i)
+      if (OutStr[i] == '\n') {                            // Left justify
+        OutStr[i] = '\\';
+        OutStr.insert(OutStr.begin()+i+1, 'l');
+      }
+
+    return OutStr;
+#else
+    return "";
+#endif
+  }
+};
+} // end namespace llvm
diff --git a/clang/lib/Analysis/CFGReachabilityAnalysis.cpp b/clang/lib/Analysis/CFGReachabilityAnalysis.cpp
new file mode 100644
index 0000000..e77e72f
--- /dev/null
+++ b/clang/lib/Analysis/CFGReachabilityAnalysis.cpp
@@ -0,0 +1,76 @@
+//==- CFGReachabilityAnalysis.cpp - Basic reachability analysis --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a flow-sensitive, (mostly) path-insensitive reachability
+// analysis based on Clang's CFGs.  Clients can query if a given basic block
+// is reachable within the CFG.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SmallVector.h"
+#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
+#include "clang/Analysis/CFG.h"
+
+using namespace clang;
+
+CFGReverseBlockReachabilityAnalysis::CFGReverseBlockReachabilityAnalysis(const CFG &cfg)
+  : analyzed(cfg.getNumBlockIDs(), false) {}
+
+bool CFGReverseBlockReachabilityAnalysis::isReachable(const CFGBlock *Src,
+                                          const CFGBlock *Dst) {
+
+  const unsigned DstBlockID = Dst->getBlockID();
+  
+  // If we haven't analyzed the destination node, run the analysis now
+  if (!analyzed[DstBlockID]) {
+    mapReachability(Dst);
+    analyzed[DstBlockID] = true;
+  }
+  
+  // Return the cached result
+  return reachable[DstBlockID][Src->getBlockID()];
+}
+
+// Maps reachability to a common node by walking the predecessors of the
+// destination node.
+void CFGReverseBlockReachabilityAnalysis::mapReachability(const CFGBlock *Dst) {
+  SmallVector<const CFGBlock *, 11> worklist;
+  llvm::BitVector visited(analyzed.size());
+  
+  ReachableSet &DstReachability = reachable[Dst->getBlockID()];
+  DstReachability.resize(analyzed.size(), false);
+  
+  // Start searching from the destination node, since we commonly will perform
+  // multiple queries relating to a destination node.
+  worklist.push_back(Dst);
+  bool firstRun = true;
+  
+  while (!worklist.empty()) {    
+    const CFGBlock *block = worklist.back();
+    worklist.pop_back();
+    
+    if (visited[block->getBlockID()])
+      continue;
+    visited[block->getBlockID()] = true;
+    
+    // Update reachability information for this node -> Dst
+    if (!firstRun) {
+      // Don't insert Dst -> Dst unless it was a predecessor of itself
+      DstReachability[block->getBlockID()] = true;
+    }
+    else
+      firstRun = false;
+    
+    // Add the predecessors to the worklist.
+    for (CFGBlock::const_pred_iterator i = block->pred_begin(), 
+         e = block->pred_end(); i != e; ++i) {
+      worklist.push_back(*i);
+    }
+  }
+}
diff --git a/clang/lib/Analysis/CFGStmtMap.cpp b/clang/lib/Analysis/CFGStmtMap.cpp
new file mode 100644
index 0000000..16df676
--- /dev/null
+++ b/clang/lib/Analysis/CFGStmtMap.cpp
@@ -0,0 +1,91 @@
+//===--- CFGStmtMap.h - Map from Stmt* to CFGBlock* -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the CFGStmtMap class, which defines a mapping from
+//  Stmt* to CFGBlock*
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/DenseMap.h"
+#include "clang/AST/ParentMap.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/CFGStmtMap.h"
+
+using namespace clang;
+
+typedef llvm::DenseMap<const Stmt*, CFGBlock*> SMap;
+static SMap *AsMap(void *m) { return (SMap*) m; }
+
+CFGStmtMap::~CFGStmtMap() { delete AsMap(M); }
+
+CFGBlock *CFGStmtMap::getBlock(Stmt *S) {  
+  SMap *SM = AsMap(M);
+  Stmt *X = S;
+
+  // If 'S' isn't in the map, walk the ParentMap to see if one of its ancestors
+  // is in the map.
+  while (X) {
+    SMap::iterator I = SM->find(X);
+    if (I != SM->end()) {
+      CFGBlock *B = I->second;
+      // Memoize this lookup.
+      if (X != S)
+        (*SM)[X] = B;
+      return B;
+    }
+
+    X = PM->getParentIgnoreParens(X);
+  }
+  
+  return 0;
+}
+
+static void Accumulate(SMap &SM, CFGBlock *B) {
+  // First walk the block-level expressions.
+  for (CFGBlock::iterator I = B->begin(), E = B->end(); I != E; ++I) {
+    const CFGElement &CE = *I;
+    const CFGStmt *CS = CE.getAs<CFGStmt>();
+    if (!CS)
+      continue;
+    
+    CFGBlock *&Entry = SM[CS->getStmt()];
+    // If 'Entry' is already initialized (e.g., a terminator was already),
+    // skip.
+    if (Entry)
+      continue;
+      
+    Entry = B;
+    
+  }
+  
+  // Look at the label of the block.
+  if (Stmt *Label = B->getLabel())
+    SM[Label] = B;
+
+  // Finally, look at the terminator.  If the terminator was already added
+  // because it is a block-level expression in another block, overwrite
+  // that mapping.
+  if (Stmt *Term = B->getTerminator())
+    SM[Term] = B;
+}
+
+CFGStmtMap *CFGStmtMap::Build(CFG *C, ParentMap *PM) {
+  if (!C || !PM)
+    return 0;
+
+  SMap *SM = new SMap();
+
+  // Walk all blocks, accumulating the block-level expressions, labels,
+  // and terminators.  
+  for (CFG::iterator I = C->begin(), E = C->end(); I != E; ++I)
+    Accumulate(*SM, *I);
+
+  return new CFGStmtMap(PM, SM);
+}
+
diff --git a/clang/lib/Analysis/CMakeLists.txt b/clang/lib/Analysis/CMakeLists.txt
new file mode 100644
index 0000000..bede002
--- /dev/null
+++ b/clang/lib/Analysis/CMakeLists.txt
@@ -0,0 +1,25 @@
+set(LLVM_USED_LIBS clangBasic clangAST)
+
+add_clang_library(clangAnalysis
+  AnalysisDeclContext.cpp
+  CallGraph.cpp
+  CFG.cpp
+  CFGReachabilityAnalysis.cpp
+  CFGStmtMap.cpp
+  CocoaConventions.cpp
+  Dominators.cpp
+  FormatString.cpp
+  Interval.cpp
+  LiveVariables.cpp
+  PostOrderCFGView.cpp
+  PrintfFormatString.cpp
+  ProgramPoint.cpp
+  PseudoConstantAnalysis.cpp
+  ReachableCode.cpp
+  ScanfFormatString.cpp
+  ThreadSafety.cpp
+  UninitializedValues.cpp
+  )
+
+add_dependencies(clangAnalysis ClangAttrClasses ClangAttrList
+                 ClangDiagnosticAnalysis ClangDeclNodes ClangStmtNodes)
diff --git a/clang/lib/Analysis/CallGraph.cpp b/clang/lib/Analysis/CallGraph.cpp
new file mode 100644
index 0000000..96a16c3
--- /dev/null
+++ b/clang/lib/Analysis/CallGraph.cpp
@@ -0,0 +1,184 @@
+//== CallGraph.cpp - AST-based Call graph  ----------------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the AST-based CallGraph.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Analysis/CallGraph.h"
+
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/StmtVisitor.h"
+
+#include "llvm/Support/GraphWriter.h"
+
+using namespace clang;
+
+namespace {
+/// A helper class, which walks the AST and locates all the call sites in the
+/// given function body.
+class CGBuilder : public StmtVisitor<CGBuilder> {
+  CallGraph *G;
+  const Decl *FD;
+  CallGraphNode *CallerNode;
+
+public:
+  CGBuilder(CallGraph *g, const Decl *D, CallGraphNode *N)
+    : G(g), FD(D), CallerNode(N) {}
+
+  void VisitStmt(Stmt *S) { VisitChildren(S); }
+
+  void VisitCallExpr(CallExpr *CE) {
+    // TODO: We need to handle ObjC method calls as well.
+    if (FunctionDecl *CalleeDecl = CE->getDirectCallee())
+      if (G->includeInGraph(CalleeDecl)) {
+        CallGraphNode *CalleeNode = G->getOrInsertNode(CalleeDecl);
+        CallerNode->addCallee(CalleeNode, G);
+      }
+  }
+
+  void VisitChildren(Stmt *S) {
+    for (Stmt::child_range I = S->children(); I; ++I)
+      if (*I)
+        static_cast<CGBuilder*>(this)->Visit(*I);
+  }
+};
+
+} // end anonymous namespace
+
+CallGraph::CallGraph() {
+  Root = getOrInsertNode(0);
+}
+
+CallGraph::~CallGraph() {
+  if (!FunctionMap.empty()) {
+    for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+        I != E; ++I)
+      delete I->second;
+    FunctionMap.clear();
+  }
+}
+
+bool CallGraph::includeInGraph(const Decl *D) {
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    // We skip function template definitions, as their semantics is
+    // only determined when they are instantiated.
+    if (!FD->isThisDeclarationADefinition() ||
+        FD->isDependentContext())
+      return false;
+
+    IdentifierInfo *II = FD->getIdentifier();
+    if (II && II->getName().startswith("__inline"))
+      return false;
+  }
+
+  if (const ObjCMethodDecl *ID = dyn_cast<ObjCMethodDecl>(D)) {
+    if (!ID->isThisDeclarationADefinition())
+      return false;
+  }
+
+  return true;
+}
+
+void CallGraph::addNodeForDecl(Decl* D, bool IsGlobal) {
+  assert(D);
+
+  // Do nothing if the node already exists.
+  if (FunctionMap.find(D) != FunctionMap.end())
+    return;
+
+  // Allocate a new node, mark it as root, and process it's calls.
+  CallGraphNode *Node = getOrInsertNode(D);
+  if (IsGlobal)
+    Root->addCallee(Node, this);
+
+  // Process all the calls by this function as well.
+  CGBuilder builder(this, D, Node);
+  if (Stmt *Body = D->getBody())
+    builder.Visit(Body);
+}
+
+CallGraphNode *CallGraph::getNode(const Decl *F) const {
+  FunctionMapTy::const_iterator I = FunctionMap.find(F);
+  if (I == FunctionMap.end()) return 0;
+  return I->second;
+}
+
+CallGraphNode *CallGraph::getOrInsertNode(Decl *F) {
+  CallGraphNode *&Node = FunctionMap[F];
+  if (Node)
+    return Node;
+
+  Node = new CallGraphNode(F);
+  // If not root, add to the parentless list.
+  if (F != 0)
+    ParentlessNodes.insert(Node);
+  return Node;
+}
+
+void CallGraph::print(raw_ostream &OS) const {
+  OS << " --- Call graph Dump --- \n";
+  for (const_iterator I = begin(), E = end(); I != E; ++I) {
+    OS << "  Function: ";
+    if (I->second == Root)
+      OS << "< root >";
+    else
+      I->second->print(OS);
+    OS << " calls: ";
+    for (CallGraphNode::iterator CI = I->second->begin(),
+        CE = I->second->end(); CI != CE; ++CI) {
+      assert(*CI != Root && "No one can call the root node.");
+      (*CI)->print(OS);
+      OS << " ";
+    }
+    OS << '\n';
+  }
+  OS.flush();
+}
+
+void CallGraph::dump() const {
+  print(llvm::errs());
+}
+
+void CallGraph::viewGraph() const {
+  llvm::ViewGraph(this, "CallGraph");
+}
+
+StringRef CallGraphNode::getName() const {
+  if (const FunctionDecl *D = dyn_cast_or_null<FunctionDecl>(FD))
+    if (const IdentifierInfo *II = D->getIdentifier())
+      return II->getName();
+    return "< >";
+}
+
+void CallGraphNode::print(raw_ostream &os) const {
+  os << getName();
+}
+
+void CallGraphNode::dump() const {
+  print(llvm::errs());
+}
+
+namespace llvm {
+
+template <>
+struct DOTGraphTraits<const CallGraph*> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+
+  static std::string getNodeLabel(const CallGraphNode *Node,
+                                  const CallGraph *CG) {
+    if (CG->getRoot() == Node) {
+      return "< root >";
+    }
+    return Node->getName();
+  }
+
+};
+}
diff --git a/clang/lib/Analysis/CocoaConventions.cpp b/clang/lib/Analysis/CocoaConventions.cpp
new file mode 100644
index 0000000..7e9e38f
--- /dev/null
+++ b/clang/lib/Analysis/CocoaConventions.cpp
@@ -0,0 +1,138 @@
+//===- CocoaConventions.h - Special handling of Cocoa conventions -*- C++ -*--//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements cocoa naming convention analysis. 
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/DomainSpecific/CocoaConventions.h"
+#include "clang/AST/Type.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclObjC.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/ErrorHandling.h"
+using namespace clang;
+using namespace ento;
+
+bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
+                      StringRef Name) {
+  // Recursively walk the typedef stack, allowing typedefs of reference types.
+  while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
+    StringRef TDName = TD->getDecl()->getIdentifier()->getName();
+    if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
+      return true;
+    // XPC unfortunately uses CF-style function names, but aren't CF types.
+    if (TDName.startswith("xpc_"))
+      return false;
+    RetTy = TD->getDecl()->getUnderlyingType();
+  }
+  
+  if (Name.empty())
+    return false;
+  
+  // Is the type void*?
+  const PointerType* PT = RetTy->getAs<PointerType>();
+  if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
+    return false;
+  
+  // Does the name start with the prefix?
+  return Name.startswith(Prefix);
+}
+
+bool coreFoundation::isCFObjectRef(QualType T) {
+  return cocoa::isRefType(T, "CF") || // Core Foundation.
+         cocoa::isRefType(T, "CG") || // Core Graphics.
+         cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
+         cocoa::isRefType(T, "DADissenter") ||
+         cocoa::isRefType(T, "DASessionRef");
+}
+
+
+bool cocoa::isCocoaObjectRef(QualType Ty) {
+  if (!Ty->isObjCObjectPointerType())
+    return false;
+  
+  const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
+  
+  // Can be true for objects with the 'NSObject' attribute.
+  if (!PT)
+    return true;
+  
+  // We assume that id<..>, id, Class, and Class<..> all represent tracked
+  // objects.
+  if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
+      PT->isObjCClassType() || PT->isObjCQualifiedClassType())
+    return true;
+  
+  // Does the interface subclass NSObject?
+  // FIXME: We can memoize here if this gets too expensive.
+  const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
+  
+  // Assume that anything declared with a forward declaration and no
+  // @interface subclasses NSObject.
+  if (!ID->hasDefinition())
+    return true;
+  
+  for ( ; ID ; ID = ID->getSuperClass())
+    if (ID->getIdentifier()->getName() == "NSObject")
+      return true;
+  
+  return false;
+}
+
+bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
+  // For now, *just* base this on the function name, not on anything else.
+
+  const IdentifierInfo *ident = fn->getIdentifier();
+  if (!ident) return false;
+  StringRef functionName = ident->getName();
+  
+  StringRef::iterator it = functionName.begin();
+  StringRef::iterator start = it;
+  StringRef::iterator endI = functionName.end();
+    
+  while (true) {
+    // Scan for the start of 'create' or 'copy'.
+    for ( ; it != endI ; ++it) {
+      // Search for the first character.  It can either be 'C' or 'c'.
+      char ch = *it;
+      if (ch == 'C' || ch == 'c') {
+        // Make sure this isn't something like 'recreate' or 'Scopy'.
+        if (ch == 'c' && it != start && isalpha(*(it - 1)))
+          continue;
+
+        ++it;
+        break;
+      }
+    }
+
+    // Did we hit the end of the string?  If so, we didn't find a match.
+    if (it == endI)
+      return false;
+    
+    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
+    // character.
+    StringRef suffix = functionName.substr(it - start);
+    if (suffix.startswith("reate")) {
+      it += 5;
+    }
+    else if (suffix.startswith("opy")) {
+      it += 3;
+    } else {
+      // Keep scanning.
+      continue;
+    }
+    
+    if (it == endI || !islower(*it))
+      return true;
+  
+    // If we matched a lowercase character, it isn't the end of the
+    // word.  Keep scanning.
+  }
+}
diff --git a/clang/lib/Analysis/Dominators.cpp b/clang/lib/Analysis/Dominators.cpp
new file mode 100644
index 0000000..0e02c6d
--- /dev/null
+++ b/clang/lib/Analysis/Dominators.cpp
@@ -0,0 +1,14 @@
+//=- Dominators.cpp - Implementation of dominators tree for Clang CFG C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/Dominators.h"
+
+using namespace clang;
+
+void DominatorTree::anchor() { }
diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
new file mode 100644
index 0000000..ba45865
--- /dev/null
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -0,0 +1,678 @@
+// FormatString.cpp - Common stuff for handling printf/scanf formats -*- C++ -*-
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Shared details for processing format strings of printf and scanf
+// (and friends).
+//
+//===----------------------------------------------------------------------===//
+
+#include "FormatStringParsing.h"
+#include "clang/Basic/LangOptions.h"
+
+using clang::analyze_format_string::ArgTypeResult;
+using clang::analyze_format_string::FormatStringHandler;
+using clang::analyze_format_string::FormatSpecifier;
+using clang::analyze_format_string::LengthModifier;
+using clang::analyze_format_string::OptionalAmount;
+using clang::analyze_format_string::PositionContext;
+using clang::analyze_format_string::ConversionSpecifier;
+using namespace clang;
+
+// Key function to FormatStringHandler.
+FormatStringHandler::~FormatStringHandler() {}
+
+//===----------------------------------------------------------------------===//
+// Functions for parsing format strings components in both printf and
+// scanf format strings.
+//===----------------------------------------------------------------------===//
+
+OptionalAmount
+clang::analyze_format_string::ParseAmount(const char *&Beg, const char *E) {
+  const char *I = Beg;
+  UpdateOnReturn <const char*> UpdateBeg(Beg, I);
+
+  unsigned accumulator = 0;
+  bool hasDigits = false;
+
+  for ( ; I != E; ++I) {
+    char c = *I;
+    if (c >= '0' && c <= '9') {
+      hasDigits = true;
+      accumulator = (accumulator * 10) + (c - '0');
+      continue;
+    }
+
+    if (hasDigits)
+      return OptionalAmount(OptionalAmount::Constant, accumulator, Beg, I - Beg,
+          false);
+
+    break;
+  }
+
+  return OptionalAmount();
+}
+
+OptionalAmount
+clang::analyze_format_string::ParseNonPositionAmount(const char *&Beg,
+                                                     const char *E,
+                                                     unsigned &argIndex) {
+  if (*Beg == '*') {
+    ++Beg;
+    return OptionalAmount(OptionalAmount::Arg, argIndex++, Beg, 0, false);
+  }
+
+  return ParseAmount(Beg, E);
+}
+
+OptionalAmount
+clang::analyze_format_string::ParsePositionAmount(FormatStringHandler &H,
+                                                  const char *Start,
+                                                  const char *&Beg,
+                                                  const char *E,
+                                                  PositionContext p) {
+  if (*Beg == '*') {
+    const char *I = Beg + 1;
+    const OptionalAmount &Amt = ParseAmount(I, E);
+
+    if (Amt.getHowSpecified() == OptionalAmount::NotSpecified) {
+      H.HandleInvalidPosition(Beg, I - Beg, p);
+      return OptionalAmount(false);
+    }
+
+    if (I == E) {
+      // No more characters left?
+      H.HandleIncompleteSpecifier(Start, E - Start);
+      return OptionalAmount(false);
+    }
+
+    assert(Amt.getHowSpecified() == OptionalAmount::Constant);
+
+    if (*I == '$') {
+      // Handle positional arguments
+
+      // Special case: '*0$', since this is an easy mistake.
+      if (Amt.getConstantAmount() == 0) {
+        H.HandleZeroPosition(Beg, I - Beg + 1);
+        return OptionalAmount(false);
+      }
+
+      const char *Tmp = Beg;
+      Beg = ++I;
+
+      return OptionalAmount(OptionalAmount::Arg, Amt.getConstantAmount() - 1,
+                            Tmp, 0, true);
+    }
+
+    H.HandleInvalidPosition(Beg, I - Beg, p);
+    return OptionalAmount(false);
+  }
+
+  return ParseAmount(Beg, E);
+}
+
+
+bool
+clang::analyze_format_string::ParseFieldWidth(FormatStringHandler &H,
+                                              FormatSpecifier &CS,
+                                              const char *Start,
+                                              const char *&Beg, const char *E,
+                                              unsigned *argIndex) {
+  // FIXME: Support negative field widths.
+  if (argIndex) {
+    CS.setFieldWidth(ParseNonPositionAmount(Beg, E, *argIndex));
+  }
+  else {
+    const OptionalAmount Amt =
+      ParsePositionAmount(H, Start, Beg, E,
+                          analyze_format_string::FieldWidthPos);
+
+    if (Amt.isInvalid())
+      return true;
+    CS.setFieldWidth(Amt);
+  }
+  return false;
+}
+
+bool
+clang::analyze_format_string::ParseArgPosition(FormatStringHandler &H,
+                                               FormatSpecifier &FS,
+                                               const char *Start,
+                                               const char *&Beg,
+                                               const char *E) {
+  const char *I = Beg;
+
+  const OptionalAmount &Amt = ParseAmount(I, E);
+
+  if (I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  if (Amt.getHowSpecified() == OptionalAmount::Constant && *(I++) == '$') {
+    // Warn that positional arguments are non-standard.
+    H.HandlePosition(Start, I - Start);
+
+    // Special case: '%0$', since this is an easy mistake.
+    if (Amt.getConstantAmount() == 0) {
+      H.HandleZeroPosition(Start, I - Start);
+      return true;
+    }
+
+    FS.setArgIndex(Amt.getConstantAmount() - 1);
+    FS.setUsesPositionalArg();
+    // Update the caller's pointer if we decided to consume
+    // these characters.
+    Beg = I;
+    return false;
+  }
+
+  return false;
+}
+
+bool
+clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
+                                                  const char *&I,
+                                                  const char *E,
+                                                  const LangOptions &LO,
+                                                  bool IsScanf) {
+  LengthModifier::Kind lmKind = LengthModifier::None;
+  const char *lmPosition = I;
+  switch (*I) {
+    default:
+      return false;
+    case 'h':
+      ++I;
+      lmKind = (I != E && *I == 'h') ? (++I, LengthModifier::AsChar)
+                                     : LengthModifier::AsShort;
+      break;
+    case 'l':
+      ++I;
+      lmKind = (I != E && *I == 'l') ? (++I, LengthModifier::AsLongLong)
+                                     : LengthModifier::AsLong;
+      break;
+    case 'j': lmKind = LengthModifier::AsIntMax;     ++I; break;
+    case 'z': lmKind = LengthModifier::AsSizeT;      ++I; break;
+    case 't': lmKind = LengthModifier::AsPtrDiff;    ++I; break;
+    case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
+    case 'q': lmKind = LengthModifier::AsQuad;       ++I; break;
+    case 'a':
+      if (IsScanf && !LO.C99 && !LO.CPlusPlus0x) {
+        // For scanf in C90, look at the next character to see if this should
+        // be parsed as the GNU extension 'a' length modifier. If not, this
+        // will be parsed as a conversion specifier.
+        ++I;
+        if (I != E && (*I == 's' || *I == 'S' || *I == '[')) {
+          lmKind = LengthModifier::AsAllocate;
+          break;
+        }
+        --I;
+      }
+      return false;
+    case 'm':
+      if (IsScanf) {
+        lmKind = LengthModifier::AsMAllocate;
+        ++I;
+        break;
+      }
+      return false;
+  }
+  LengthModifier lm(lmPosition, lmKind);
+  FS.setLengthModifier(lm);
+  return true;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on ArgTypeResult.
+//===----------------------------------------------------------------------===//
+
+bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
+  switch (K) {
+    case InvalidTy:
+      llvm_unreachable("ArgTypeResult must be valid");
+
+    case UnknownTy:
+      return true;
+      
+    case AnyCharTy: {
+      if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
+        switch (BT->getKind()) {
+          default:
+            break;
+          case BuiltinType::Char_S:
+          case BuiltinType::SChar:
+          case BuiltinType::UChar:
+          case BuiltinType::Char_U:
+            return true;            
+        }
+      return false;
+    }
+      
+    case SpecificTy: {
+      argTy = C.getCanonicalType(argTy).getUnqualifiedType();
+      if (T == argTy)
+        return true;
+      // Check for "compatible types".
+      if (const BuiltinType *BT = argTy->getAs<BuiltinType>())
+        switch (BT->getKind()) {
+          default:
+            break;
+          case BuiltinType::Char_S:
+          case BuiltinType::SChar:
+            return T == C.UnsignedCharTy;
+          case BuiltinType::Char_U:
+          case BuiltinType::UChar:                    
+            return T == C.SignedCharTy;
+          case BuiltinType::Short:
+            return T == C.UnsignedShortTy;
+          case BuiltinType::UShort:
+            return T == C.ShortTy;
+          case BuiltinType::Int:
+            return T == C.UnsignedIntTy;
+          case BuiltinType::UInt:
+            return T == C.IntTy;
+          case BuiltinType::Long:
+            return T == C.UnsignedLongTy;
+          case BuiltinType::ULong:
+            return T == C.LongTy;
+          case BuiltinType::LongLong:
+            return T == C.UnsignedLongLongTy;
+          case BuiltinType::ULongLong:
+            return T == C.LongLongTy;
+        }
+      return false;
+    }
+
+    case CStrTy: {
+      const PointerType *PT = argTy->getAs<PointerType>();
+      if (!PT)
+        return false;
+      QualType pointeeTy = PT->getPointeeType();
+      if (const BuiltinType *BT = pointeeTy->getAs<BuiltinType>())
+        switch (BT->getKind()) {
+          case BuiltinType::Void:
+          case BuiltinType::Char_U:
+          case BuiltinType::UChar:
+          case BuiltinType::Char_S:
+          case BuiltinType::SChar:
+            return true;
+          default:
+            break;
+        }
+
+      return false;
+    }
+
+    case WCStrTy: {
+      const PointerType *PT = argTy->getAs<PointerType>();
+      if (!PT)
+        return false;
+      QualType pointeeTy =
+        C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
+      return pointeeTy == C.getWCharType();
+    }
+    
+    case WIntTy: {
+      // Instead of doing a lookup for the definition of 'wint_t' (which
+      // is defined by the system headers) instead see if wchar_t and
+      // the argument type promote to the same type.
+      QualType PromoWChar =
+        C.getWCharType()->isPromotableIntegerType() 
+          ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
+      QualType PromoArg = 
+        argTy->isPromotableIntegerType()
+          ? C.getPromotedIntegerType(argTy) : argTy;
+      
+      PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
+      PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
+      
+      return PromoWChar == PromoArg;
+    }
+
+    case CPointerTy:
+      return argTy->isPointerType() || argTy->isObjCObjectPointerType() ||
+             argTy->isBlockPointerType() || argTy->isNullPtrType();
+
+    case ObjCPointerTy: {
+      if (argTy->getAs<ObjCObjectPointerType>() ||
+          argTy->getAs<BlockPointerType>())
+        return true;
+      
+      // Handle implicit toll-free bridging.
+      if (const PointerType *PT = argTy->getAs<PointerType>()) {
+        // Things such as CFTypeRef are really just opaque pointers
+        // to C structs representing CF types that can often be bridged
+        // to Objective-C objects.  Since the compiler doesn't know which
+        // structs can be toll-free bridged, we just accept them all.
+        QualType pointee = PT->getPointeeType();
+        if (pointee->getAsStructureType() || pointee->isVoidType())
+          return true;
+      }
+      return false;      
+    }
+  }
+
+  llvm_unreachable("Invalid ArgTypeResult Kind!");
+}
+
+QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
+  switch (K) {
+    case InvalidTy:
+      llvm_unreachable("No representative type for Invalid ArgTypeResult");
+    case UnknownTy:
+      return QualType();
+    case AnyCharTy:
+      return C.CharTy;
+    case SpecificTy:
+      return T;
+    case CStrTy:
+      return C.getPointerType(C.CharTy);
+    case WCStrTy:
+      return C.getPointerType(C.getWCharType());
+    case ObjCPointerTy:
+      return C.ObjCBuiltinIdTy;
+    case CPointerTy:
+      return C.VoidPtrTy;
+    case WIntTy: {
+      QualType WC = C.getWCharType();
+      return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
+    }
+  }
+
+  llvm_unreachable("Invalid ArgTypeResult Kind!");
+}
+
+std::string ArgTypeResult::getRepresentativeTypeName(ASTContext &C) const {
+  std::string S = getRepresentativeType(C).getAsString();
+  if (Name && S != Name)
+    return std::string("'") + Name + "' (aka '" + S + "')";
+  return std::string("'") + S + "'";
+}
+
+
+//===----------------------------------------------------------------------===//
+// Methods on OptionalAmount.
+//===----------------------------------------------------------------------===//
+
+ArgTypeResult
+analyze_format_string::OptionalAmount::getArgType(ASTContext &Ctx) const {
+  return Ctx.IntTy;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on LengthModifier.
+//===----------------------------------------------------------------------===//
+
+const char *
+analyze_format_string::LengthModifier::toString() const {
+  switch (kind) {
+  case AsChar:
+    return "hh";
+  case AsShort:
+    return "h";
+  case AsLong: // or AsWideChar
+    return "l";
+  case AsLongLong:
+    return "ll";
+  case AsQuad:
+    return "q";
+  case AsIntMax:
+    return "j";
+  case AsSizeT:
+    return "z";
+  case AsPtrDiff:
+    return "t";
+  case AsLongDouble:
+    return "L";
+  case AsAllocate:
+    return "a";
+  case AsMAllocate:
+    return "m";
+  case None:
+    return "";
+  }
+  return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on ConversionSpecifier.
+//===----------------------------------------------------------------------===//
+
+const char *ConversionSpecifier::toString() const {
+  switch (kind) {
+  case dArg: return "d";
+  case iArg: return "i";
+  case oArg: return "o";
+  case uArg: return "u";
+  case xArg: return "x";
+  case XArg: return "X";
+  case fArg: return "f";
+  case FArg: return "F";
+  case eArg: return "e";
+  case EArg: return "E";
+  case gArg: return "g";
+  case GArg: return "G";
+  case aArg: return "a";
+  case AArg: return "A";
+  case cArg: return "c";
+  case sArg: return "s";
+  case pArg: return "p";
+  case nArg: return "n";
+  case PercentArg:  return "%";
+  case ScanListArg: return "[";
+  case InvalidSpecifier: return NULL;
+
+  // MacOS X unicode extensions.
+  case CArg: return "C";
+  case SArg: return "S";
+
+  // Objective-C specific specifiers.
+  case ObjCObjArg: return "@";
+
+  // GlibC specific specifiers.
+  case PrintErrno: return "m";
+  }
+  return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on OptionalAmount.
+//===----------------------------------------------------------------------===//
+
+void OptionalAmount::toString(raw_ostream &os) const {
+  switch (hs) {
+  case Invalid:
+  case NotSpecified:
+    return;
+  case Arg:
+    if (UsesDotPrefix)
+        os << ".";
+    if (usesPositionalArg())
+      os << "*" << getPositionalArgIndex() << "$";
+    else
+      os << "*";
+    break;
+  case Constant:
+    if (UsesDotPrefix)
+        os << ".";
+    os << amt;
+    break;
+  }
+}
+
+bool FormatSpecifier::hasValidLengthModifier() const {
+  switch (LM.getKind()) {
+    case LengthModifier::None:
+      return true;
+      
+    // Handle most integer flags
+    case LengthModifier::AsChar:
+    case LengthModifier::AsShort:
+    case LengthModifier::AsLongLong:
+    case LengthModifier::AsQuad:
+    case LengthModifier::AsIntMax:
+    case LengthModifier::AsSizeT:
+    case LengthModifier::AsPtrDiff:
+      switch (CS.getKind()) {
+        case ConversionSpecifier::dArg:
+        case ConversionSpecifier::iArg:
+        case ConversionSpecifier::oArg:
+        case ConversionSpecifier::uArg:
+        case ConversionSpecifier::xArg:
+        case ConversionSpecifier::XArg:
+        case ConversionSpecifier::nArg:
+          return true;
+        default:
+          return false;
+      }
+      
+    // Handle 'l' flag
+    case LengthModifier::AsLong:
+      switch (CS.getKind()) {
+        case ConversionSpecifier::dArg:
+        case ConversionSpecifier::iArg:
+        case ConversionSpecifier::oArg:
+        case ConversionSpecifier::uArg:
+        case ConversionSpecifier::xArg:
+        case ConversionSpecifier::XArg:
+        case ConversionSpecifier::aArg:
+        case ConversionSpecifier::AArg:
+        case ConversionSpecifier::fArg:
+        case ConversionSpecifier::FArg:
+        case ConversionSpecifier::eArg:
+        case ConversionSpecifier::EArg:
+        case ConversionSpecifier::gArg:
+        case ConversionSpecifier::GArg:
+        case ConversionSpecifier::nArg:
+        case ConversionSpecifier::cArg:
+        case ConversionSpecifier::sArg:
+        case ConversionSpecifier::ScanListArg:
+          return true;
+        default:
+          return false;
+      }
+      
+    case LengthModifier::AsLongDouble:
+      switch (CS.getKind()) {
+        case ConversionSpecifier::aArg:
+        case ConversionSpecifier::AArg:
+        case ConversionSpecifier::fArg:
+        case ConversionSpecifier::FArg:
+        case ConversionSpecifier::eArg:
+        case ConversionSpecifier::EArg:
+        case ConversionSpecifier::gArg:
+        case ConversionSpecifier::GArg:
+          return true;
+        // GNU extension.
+        case ConversionSpecifier::dArg:
+        case ConversionSpecifier::iArg:
+        case ConversionSpecifier::oArg:
+        case ConversionSpecifier::uArg:
+        case ConversionSpecifier::xArg:
+        case ConversionSpecifier::XArg:
+          return true;
+        default:
+          return false;
+      }
+
+    case LengthModifier::AsAllocate:
+      switch (CS.getKind()) {
+        case ConversionSpecifier::sArg:
+        case ConversionSpecifier::SArg:
+        case ConversionSpecifier::ScanListArg:
+          return true;
+        default:
+          return false;
+      }
+
+    case LengthModifier::AsMAllocate:
+      switch (CS.getKind()) {
+        case ConversionSpecifier::cArg:
+        case ConversionSpecifier::CArg:
+        case ConversionSpecifier::sArg:
+        case ConversionSpecifier::SArg:
+        case ConversionSpecifier::ScanListArg:
+          return true;
+        default:
+          return false;
+      }
+  }
+  llvm_unreachable("Invalid LengthModifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardLengthModifier() const {
+  switch (LM.getKind()) {
+    case LengthModifier::None:
+    case LengthModifier::AsChar:
+    case LengthModifier::AsShort:
+    case LengthModifier::AsLong:
+    case LengthModifier::AsLongLong:
+    case LengthModifier::AsIntMax:
+    case LengthModifier::AsSizeT:
+    case LengthModifier::AsPtrDiff:
+    case LengthModifier::AsLongDouble:
+      return true;
+    case LengthModifier::AsAllocate:
+    case LengthModifier::AsMAllocate:
+    case LengthModifier::AsQuad:
+      return false;
+  }
+  llvm_unreachable("Invalid LengthModifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardConversionSpecifier(const LangOptions &LangOpt) const {
+  switch (CS.getKind()) {
+    case ConversionSpecifier::cArg:
+    case ConversionSpecifier::dArg:
+    case ConversionSpecifier::iArg:
+    case ConversionSpecifier::oArg:
+    case ConversionSpecifier::uArg:
+    case ConversionSpecifier::xArg:
+    case ConversionSpecifier::XArg:
+    case ConversionSpecifier::fArg:
+    case ConversionSpecifier::FArg:
+    case ConversionSpecifier::eArg:
+    case ConversionSpecifier::EArg:
+    case ConversionSpecifier::gArg:
+    case ConversionSpecifier::GArg:
+    case ConversionSpecifier::aArg:
+    case ConversionSpecifier::AArg:
+    case ConversionSpecifier::sArg:
+    case ConversionSpecifier::pArg:
+    case ConversionSpecifier::nArg:
+    case ConversionSpecifier::ObjCObjArg:
+    case ConversionSpecifier::ScanListArg:
+    case ConversionSpecifier::PercentArg:
+      return true;
+    case ConversionSpecifier::CArg:
+    case ConversionSpecifier::SArg:
+      return LangOpt.ObjC1 || LangOpt.ObjC2;
+    case ConversionSpecifier::InvalidSpecifier:
+    case ConversionSpecifier::PrintErrno:
+      return false;
+  }
+  llvm_unreachable("Invalid ConversionSpecifier Kind!");
+}
+
+bool FormatSpecifier::hasStandardLengthConversionCombination() const {
+  if (LM.getKind() == LengthModifier::AsLongDouble) {
+    switch(CS.getKind()) {
+        case ConversionSpecifier::dArg:
+        case ConversionSpecifier::iArg:
+        case ConversionSpecifier::oArg:
+        case ConversionSpecifier::uArg:
+        case ConversionSpecifier::xArg:
+        case ConversionSpecifier::XArg:
+          return false;
+        default:
+          return true;
+    }
+  }
+  return true;
+}
diff --git a/clang/lib/Analysis/FormatStringParsing.h b/clang/lib/Analysis/FormatStringParsing.h
new file mode 100644
index 0000000..f483ec6
--- /dev/null
+++ b/clang/lib/Analysis/FormatStringParsing.h
@@ -0,0 +1,74 @@
+#ifndef LLVM_CLANG_FORMAT_PARSING_H
+#define LLVM_CLANG_FORMAT_PARSING_H
+
+#include "clang/Analysis/Analyses/FormatString.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Type.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace clang {
+
+class LangOptions;
+
+template <typename T>
+class UpdateOnReturn {
+  T &ValueToUpdate;
+  const T &ValueToCopy;
+public:
+  UpdateOnReturn(T &valueToUpdate, const T &valueToCopy)
+    : ValueToUpdate(valueToUpdate), ValueToCopy(valueToCopy) {}
+
+  ~UpdateOnReturn() {
+    ValueToUpdate = ValueToCopy;
+  }
+};
+
+namespace analyze_format_string {
+  
+OptionalAmount ParseAmount(const char *&Beg, const char *E);
+OptionalAmount ParseNonPositionAmount(const char *&Beg, const char *E,
+                                      unsigned &argIndex);
+
+OptionalAmount ParsePositionAmount(FormatStringHandler &H,
+                                   const char *Start, const char *&Beg,
+                                   const char *E, PositionContext p);
+  
+bool ParseFieldWidth(FormatStringHandler &H,
+                     FormatSpecifier &CS,
+                     const char *Start, const char *&Beg, const char *E,
+                     unsigned *argIndex);
+    
+bool ParseArgPosition(FormatStringHandler &H,
+                      FormatSpecifier &CS, const char *Start,
+                      const char *&Beg, const char *E);
+
+/// Returns true if a LengthModifier was parsed and installed in the
+/// FormatSpecifier& argument, and false otherwise.
+bool ParseLengthModifier(FormatSpecifier &FS, const char *&Beg, const char *E,
+                         const LangOptions &LO, bool IsScanf = false);
+  
+template <typename T> class SpecifierResult {
+  T FS;
+  const char *Start;
+  bool Stop;
+public:
+  SpecifierResult(bool stop = false)
+  : Start(0), Stop(stop) {}
+  SpecifierResult(const char *start,
+                  const T &fs)
+  : FS(fs), Start(start), Stop(false) {}
+  
+  const char *getStart() const { return Start; }
+  bool shouldStop() const { return Stop; }
+  bool hasValue() const { return Start != 0; }
+  const T &getValue() const {
+    assert(hasValue());
+    return FS;
+  }
+  const T &getValue() { return FS; }
+};
+  
+} // end analyze_format_string namespace
+} // end clang namespace
+
+#endif
diff --git a/clang/lib/Analysis/Interval.cpp b/clang/lib/Analysis/Interval.cpp
new file mode 100644
index 0000000..bfa1ccf
--- /dev/null
+++ b/clang/lib/Analysis/Interval.cpp
@@ -0,0 +1,230 @@
+#include "clang/Analysis/Analyses/Interval.h"
+#include "clang/AST/Stmt.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/AST/StmtVisitor.h"
+
+#include "clang/Analysis/Analyses/IntervalSolver/Log.hpp"
+#include "clang/Analysis/Analyses/IntervalSolver/Complete.hpp"
+#include "clang/Analysis/Analyses/IntervalSolver/VariableAssignment.hpp"
+#include "clang/Analysis/Analyses/IntervalSolver/EquationSystem.hpp"
+  
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/Process.h"
+  
+#include <deque>
+#include <algorithm>
+#include <vector>
+#include <map>
+
+using namespace clang;
+
+typedef EquationSystem<Complete<int> > EqnSys;
+typedef Expression<Complete<int> > EqnExpr;
+
+#include <sstream>
+template<typename T>
+std::string toString(const T& obj) {
+  std::stringstream stream;
+  stream << obj;
+  return stream.str();
+}
+
+IntervalAnalysis :: IntervalAnalysis(AnalysisDeclContext &context)
+  : context(&context) {
+}
+
+IntervalAnalysis :: ~IntervalAnalysis() {
+}
+
+// Two pieces of state:
+//  -> condition protecting a node
+//  -> node's expression itself
+// We can then combine these in a straightforward way to
+// get out equation system, whereupon we can solve for what
+// we want to know. Then we can have program invariants!
+//
+// Hooray!
+
+EqnExpr* fromStmt(const Stmt*, EqnSys&);
+
+EqnExpr* fromInteger(const IntegerLiteral* expr, EqnSys& system) {
+  return &system.constant(*expr->getValue().getRawData());
+}
+
+EqnExpr* fromDeclExpr(const DeclRefExpr* expr, EqnSys& system) {
+  return &system.variable(expr->getNameInfo().getAsString());
+}
+
+EqnExpr* fromUnary(const UnaryOperator* op, EqnSys& system) {
+  switch (op->getOpcode()) {
+  case UO_PreInc:
+    break;
+  case UO_PostInc:
+    break;
+  }
+  return NULL;
+}
+
+
+Addition<Complete<int> >* add = new Addition<Complete<int> >();
+Subtraction<Complete<int> >* sub = new Subtraction<Complete<int> >();
+Multiplication<Complete<int> >* mul = new Multiplication<Complete<int> >();
+
+EqnExpr* fromBinary(const BinaryOperator* op, EqnSys& system) {
+  EqnExpr* left = fromStmt(op->getLHS()->IgnoreParenCasts(), system);
+  EqnExpr* right = fromStmt(op->getRHS()->IgnoreParenCasts(), system);
+  
+  std::vector<EqnExpr*> args;
+  args.push_back(left);
+  args.push_back(right);
+  
+  switch (op->getOpcode()) {
+  case BO_Add:
+    return &system.expression(add, args);
+  case BO_Sub:
+    return &system.expression(sub, args);
+  case BO_Mul:
+    return &system.expression(mul, args);
+  case BO_LT:
+  case BO_LE:
+  case BO_GT:
+  case BO_GE:
+    break;
+  } 
+  return NULL;
+}
+
+EqnExpr* fromDeclStmt(const DeclStmt* stmt, EqnSys& system) {
+  for (DeclStmt::const_decl_iterator it = stmt->decl_begin(),
+                                     ei = stmt->decl_end();
+       it != ei;
+       ++it) {
+    if ((*it)->getKind() == Decl::Var) {
+      const VarDecl* decl = static_cast<const VarDecl*>(*it);
+      Variable<Complete<int> > var = system.variable(decl->getNameAsString());
+      std::vector<EqnExpr*> args;
+      args.push_back(&system.constant(-infinity<Complete<int> >()));
+      args.push_back(fromStmt(decl->getInit(), system));
+      system[var] = &system.maxExpression(args);
+    }
+  }
+  return NULL;
+}
+
+EqnExpr* fromAssignment(const BinaryOperator* op, EqnSys& system) {
+  EqnExpr* left = fromStmt(op->getLHS()->IgnoreParenCasts(), system);
+  EqnExpr* right = fromStmt(op->getRHS()->IgnoreParenCasts(), system);
+  Variable<Complete<int> >* var = static_cast<Variable<Complete<int> >*>(left);
+
+  std::vector<EqnExpr*> args;
+  args.push_back(&system.constant(-infinity<Complete<int> >()));
+  args.push_back(right);
+  if (system[*var] != NULL)
+    args.push_back(system[*var]);
+  system[*var] = &system.maxExpression(args);
+
+  return NULL;
+}
+
+EqnExpr* fromStmt(const Stmt* stmt, EqnSys& system) {
+  if (!stmt)
+    return NULL;
+  switch (stmt->getStmtClass()) {
+  case Stmt::IntegerLiteralClass:
+    return fromInteger(static_cast<const IntegerLiteral*>(stmt), system);
+  case Stmt::DeclRefExprClass:
+    return fromDeclExpr(static_cast<const DeclRefExpr*>(stmt), system);
+  case Stmt::UnaryOperatorClass:
+    return fromUnary(static_cast<const UnaryOperator*>(stmt), system);
+  case Stmt::DeclStmtClass:
+    return fromDeclStmt(static_cast<const DeclStmt*>(stmt), system);
+  case Stmt::BinaryOperatorClass:
+    {
+      const BinaryOperator* binop = static_cast<const BinaryOperator*>(stmt);
+      if (binop->isAssignmentOp())
+        return fromAssignment(binop, system);
+      else
+        return fromBinary(binop, system);
+    }
+  }
+  return NULL;
+}
+
+void runOnBlock(std::string id, const CFGBlock* block, EqnSys& system) {
+  for (CFGBlock::const_iterator it = block->begin(),
+                                ei = block->end();
+       it != ei;
+       ++it) {
+    const CFGStmt* cfg_stmt = it->getAs<CFGStmt>();
+    const Stmt* stmt = static_cast<const Stmt*>(cfg_stmt->getStmt());
+    EqnExpr* expr = fromStmt(stmt, system);
+  }
+  fromStmt(block->getTerminatorCondition(), system);
+
+  /*if (terminator.getStmt() != NULL) {
+    if (terminator.getStmt()->getStmtClass() == Stmt::IfStmtClass) {
+      const IfStmt* if_stmt = static_cast<const IfStmt*>(terminator.getStmt());
+      llvm::errs() << "If: \n";
+      if_stmt->dump();
+    } else {
+      llvm::errs() << "\n";
+      terminator.getStmt()->dump();
+    }
+    }*/
+  return; // TODO: return a generated expression
+}
+
+void IntervalAnalysis::runOnAllBlocks() {
+  llvm::errs() << "Enter run on all blocks\n";
+
+  const CFG *cfg = this->context->getCFG();
+
+  EqnSys system;
+
+  std::set<const CFGBlock*> seen;
+  std::deque<const CFGBlock*> todo;
+  todo.push_back(&cfg->getEntry());
+
+  while (!todo.empty()) {
+    const CFGBlock* block = todo.front();
+    if (seen.find(todo.front()) != seen.end()) {
+      todo.pop_front();
+      continue;
+    }
+    llvm::errs() << (void*)block << "\n";
+    seen.insert(block);
+    todo.pop_front();
+    runOnBlock(toString(block), block, system);
+    llvm::errs() << "-> ";
+    for (CFGBlock::const_succ_iterator it = block->succ_begin(),
+                                       ei = block->succ_end();
+         it != ei;
+         it++ ) {
+      llvm::errs() << (void*) *it << ", ";
+      todo.push_back(*it);
+    }
+    llvm::errs() << "\n\n";
+  }
+
+  llvm::errs() << "Exit run on all blocks\n";
+
+  llvm::errs() << toString(system) << "\n";
+
+  system.indexMaxExpressions();
+  DynamicMaxStrategy<Complete<int> > strategy(system);
+  DynamicVariableAssignment<Complete<int> > rho(system, strategy);
+  strategy.setRho(rho);
+
+  for (unsigned int i = 0, size = system.variableCount(); i < size; ++i) {
+    Variable<Complete<int> >& var = system.variable(i);
+    llvm::errs() << toString(var.name()) << " = " << toString(rho[var]) << "\n";
+  }
+
+  //  cfg->dump(context->getASTContext().getLangOpts(),
+  //            llvm::sys::Process::StandardErrHasColors());
+}
+
+
+const void *IntervalAnalysis::getTag() { static int x; return &x; }
diff --git a/clang/lib/Analysis/LiveVariables.cpp b/clang/lib/Analysis/LiveVariables.cpp
new file mode 100644
index 0000000..ff6607d
--- /dev/null
+++ b/clang/lib/Analysis/LiveVariables.cpp
@@ -0,0 +1,607 @@
+#include "clang/Analysis/Analyses/LiveVariables.h"
+#include "clang/Analysis/Analyses/PostOrderCFGView.h"
+
+#include "clang/AST/Stmt.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/AST/StmtVisitor.h"
+
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/DenseMap.h"
+
+#include <deque>
+#include <algorithm>
+#include <vector>
+
+using namespace clang;
+
+namespace {
+
+class DataflowWorklist {
+  SmallVector<const CFGBlock *, 20> worklist;
+  llvm::BitVector enqueuedBlocks;
+  PostOrderCFGView *POV;
+public:
+  DataflowWorklist(const CFG &cfg, AnalysisDeclContext &Ctx)
+    : enqueuedBlocks(cfg.getNumBlockIDs()),
+      POV(Ctx.getAnalysis<PostOrderCFGView>()) {}
+  
+  void enqueueBlock(const CFGBlock *block);
+  void enqueueSuccessors(const CFGBlock *block);
+  void enqueuePredecessors(const CFGBlock *block);
+
+  const CFGBlock *dequeue();
+
+  void sortWorklist();
+};
+
+}
+
+void DataflowWorklist::enqueueBlock(const clang::CFGBlock *block) {
+  if (block && !enqueuedBlocks[block->getBlockID()]) {
+    enqueuedBlocks[block->getBlockID()] = true;
+    worklist.push_back(block);
+  }
+}
+  
+void DataflowWorklist::enqueueSuccessors(const clang::CFGBlock *block) {
+  const unsigned OldWorklistSize = worklist.size();
+  for (CFGBlock::const_succ_iterator I = block->succ_begin(),
+       E = block->succ_end(); I != E; ++I) {
+    enqueueBlock(*I);
+  }
+
+  if (OldWorklistSize == 0 || OldWorklistSize == worklist.size())
+    return;
+
+  sortWorklist();
+}
+
+void DataflowWorklist::enqueuePredecessors(const clang::CFGBlock *block) {
+  const unsigned OldWorklistSize = worklist.size();
+  for (CFGBlock::const_pred_iterator I = block->pred_begin(),
+       E = block->pred_end(); I != E; ++I) {
+    enqueueBlock(*I);
+  }
+  
+  if (OldWorklistSize == 0 || OldWorklistSize == worklist.size())
+    return;
+
+  sortWorklist();
+}
+
+void DataflowWorklist::sortWorklist() {
+  std::sort(worklist.begin(), worklist.end(), POV->getComparator());
+}
+
+const CFGBlock *DataflowWorklist::dequeue() {
+  if (worklist.empty())
+    return 0;
+  const CFGBlock *b = worklist.back();
+  worklist.pop_back();
+  enqueuedBlocks[b->getBlockID()] = false;
+  return b;
+}
+
+namespace {
+class LiveVariablesImpl {
+public:  
+  AnalysisDeclContext &analysisContext;
+  std::vector<LiveVariables::LivenessValues> cfgBlockValues;
+  llvm::ImmutableSet<const Stmt *>::Factory SSetFact;
+  llvm::ImmutableSet<const VarDecl *>::Factory DSetFact;
+  llvm::DenseMap<const CFGBlock *, LiveVariables::LivenessValues> blocksEndToLiveness;
+  llvm::DenseMap<const CFGBlock *, LiveVariables::LivenessValues> blocksBeginToLiveness;
+  llvm::DenseMap<const Stmt *, LiveVariables::LivenessValues> stmtsToLiveness;
+  llvm::DenseMap<const DeclRefExpr *, unsigned> inAssignment;
+  const bool killAtAssign;
+  
+  LiveVariables::LivenessValues
+  merge(LiveVariables::LivenessValues valsA,
+        LiveVariables::LivenessValues valsB);
+      
+  LiveVariables::LivenessValues runOnBlock(const CFGBlock *block,
+                                           LiveVariables::LivenessValues val,
+                                           LiveVariables::Observer *obs = 0);
+
+  void dumpBlockLiveness(const SourceManager& M);
+
+  LiveVariablesImpl(AnalysisDeclContext &ac, bool KillAtAssign)
+    : analysisContext(ac),
+      SSetFact(false), // Do not canonicalize ImmutableSets by default.
+      DSetFact(false), // This is a *major* performance win.
+      killAtAssign(KillAtAssign) {}
+};
+}
+
+static LiveVariablesImpl &getImpl(void *x) {
+  return *((LiveVariablesImpl *) x);
+}
+
+//===----------------------------------------------------------------------===//
+// Operations and queries on LivenessValues.
+//===----------------------------------------------------------------------===//
+
+bool LiveVariables::LivenessValues::isLive(const Stmt *S) const {
+  return liveStmts.contains(S);
+}
+
+bool LiveVariables::LivenessValues::isLive(const VarDecl *D) const {
+  return liveDecls.contains(D);
+}
+
+namespace {
+  template <typename SET>
+  SET mergeSets(SET A, SET B) {
+    if (A.isEmpty())
+      return B;
+    
+    for (typename SET::iterator it = B.begin(), ei = B.end(); it != ei; ++it) {
+      A = A.add(*it);
+    }
+    return A;
+  }
+}
+
+void LiveVariables::Observer::anchor() { }
+
+LiveVariables::LivenessValues
+LiveVariablesImpl::merge(LiveVariables::LivenessValues valsA,
+                         LiveVariables::LivenessValues valsB) {  
+  
+  llvm::ImmutableSetRef<const Stmt *>
+    SSetRefA(valsA.liveStmts.getRootWithoutRetain(), SSetFact.getTreeFactory()),
+    SSetRefB(valsB.liveStmts.getRootWithoutRetain(), SSetFact.getTreeFactory());
+                                                
+  
+  llvm::ImmutableSetRef<const VarDecl *>
+    DSetRefA(valsA.liveDecls.getRootWithoutRetain(), DSetFact.getTreeFactory()),
+    DSetRefB(valsB.liveDecls.getRootWithoutRetain(), DSetFact.getTreeFactory());
+  
+
+  SSetRefA = mergeSets(SSetRefA, SSetRefB);
+  DSetRefA = mergeSets(DSetRefA, DSetRefB);
+  
+  // asImmutableSet() canonicalizes the tree, allowing us to do an easy
+  // comparison afterwards.
+  return LiveVariables::LivenessValues(SSetRefA.asImmutableSet(),
+                                       DSetRefA.asImmutableSet());  
+}
+
+bool LiveVariables::LivenessValues::equals(const LivenessValues &V) const {
+  return liveStmts == V.liveStmts && liveDecls == V.liveDecls;
+}
+
+//===----------------------------------------------------------------------===//
+// Query methods.
+//===----------------------------------------------------------------------===//
+
+static bool isAlwaysAlive(const VarDecl *D) {
+  return D->hasGlobalStorage();
+}
+
+bool LiveVariables::isLive(const CFGBlock *B, const VarDecl *D) {
+  return isAlwaysAlive(D) || getImpl(impl).blocksEndToLiveness[B].isLive(D);
+}
+
+bool LiveVariables::isLive(const Stmt *S, const VarDecl *D) {
+  return isAlwaysAlive(D) || getImpl(impl).stmtsToLiveness[S].isLive(D);
+}
+
+bool LiveVariables::isLive(const Stmt *Loc, const Stmt *S) {
+  return getImpl(impl).stmtsToLiveness[Loc].isLive(S);
+}
+
+//===----------------------------------------------------------------------===//
+// Dataflow computation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class TransferFunctions : public StmtVisitor<TransferFunctions> {
+  LiveVariablesImpl &LV;
+  LiveVariables::LivenessValues &val;
+  LiveVariables::Observer *observer;
+  const CFGBlock *currentBlock;
+public:
+  TransferFunctions(LiveVariablesImpl &im,
+                    LiveVariables::LivenessValues &Val,
+                    LiveVariables::Observer *Observer,
+                    const CFGBlock *CurrentBlock)
+  : LV(im), val(Val), observer(Observer), currentBlock(CurrentBlock) {}
+
+  void VisitBinaryOperator(BinaryOperator *BO);
+  void VisitBlockExpr(BlockExpr *BE);
+  void VisitDeclRefExpr(DeclRefExpr *DR);  
+  void VisitDeclStmt(DeclStmt *DS);
+  void VisitObjCForCollectionStmt(ObjCForCollectionStmt *OS);
+  void VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *UE);
+  void VisitUnaryOperator(UnaryOperator *UO);
+  void Visit(Stmt *S);
+};
+}
+
+static const VariableArrayType *FindVA(QualType Ty) {
+  const Type *ty = Ty.getTypePtr();
+  while (const ArrayType *VT = dyn_cast<ArrayType>(ty)) {
+    if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(VT))
+      if (VAT->getSizeExpr())
+        return VAT;
+    
+    ty = VT->getElementType().getTypePtr();
+  }
+  
+  return 0;
+}
+
+static const Stmt *LookThroughStmt(const Stmt *S) {
+  while (S) {
+    if (const Expr *Ex = dyn_cast<Expr>(S))
+      S = Ex->IgnoreParens();    
+    if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(S)) {
+      S = EWC->getSubExpr();
+      continue;
+    }
+    if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(S)) {
+      S = OVE->getSourceExpr();
+      continue;
+    }
+    break;
+  }
+  return S;
+}
+
+static void AddLiveStmt(llvm::ImmutableSet<const Stmt *> &Set,
+                        llvm::ImmutableSet<const Stmt *>::Factory &F,
+                        const Stmt *S) {
+  Set = F.add(Set, LookThroughStmt(S));
+}
+
+void TransferFunctions::Visit(Stmt *S) {
+  if (observer)
+    observer->observeStmt(S, currentBlock, val);
+  
+  StmtVisitor<TransferFunctions>::Visit(S);
+  
+  if (isa<Expr>(S)) {
+    val.liveStmts = LV.SSetFact.remove(val.liveStmts, S);
+  }
+
+  // Mark all children expressions live.
+  
+  switch (S->getStmtClass()) {
+    default:
+      break;
+    case Stmt::StmtExprClass: {
+      // For statement expressions, look through the compound statement.
+      S = cast<StmtExpr>(S)->getSubStmt();
+      break;
+    }
+    case Stmt::CXXMemberCallExprClass: {
+      // Include the implicit "this" pointer as being live.
+      CXXMemberCallExpr *CE = cast<CXXMemberCallExpr>(S);
+      if (Expr *ImplicitObj = CE->getImplicitObjectArgument()) {
+        AddLiveStmt(val.liveStmts, LV.SSetFact, ImplicitObj);
+      }
+      break;
+    }
+    case Stmt::DeclStmtClass: {
+      const DeclStmt *DS = cast<DeclStmt>(S);
+      if (const VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl())) {
+        for (const VariableArrayType* VA = FindVA(VD->getType());
+             VA != 0; VA = FindVA(VA->getElementType())) {
+          AddLiveStmt(val.liveStmts, LV.SSetFact, VA->getSizeExpr());
+        }
+      }
+      break;
+    }
+    case Stmt::PseudoObjectExprClass: {
+      // A pseudo-object operation only directly consumes its result
+      // expression.
+      Expr *child = cast<PseudoObjectExpr>(S)->getResultExpr();
+      if (!child) return;
+      if (OpaqueValueExpr *OV = dyn_cast<OpaqueValueExpr>(child))
+        child = OV->getSourceExpr();
+      child = child->IgnoreParens();
+      val.liveStmts = LV.SSetFact.add(val.liveStmts, child);
+      return;
+    }
+
+    // FIXME: These cases eventually shouldn't be needed.
+    case Stmt::ExprWithCleanupsClass: {
+      S = cast<ExprWithCleanups>(S)->getSubExpr();
+      break;
+    }
+    case Stmt::CXXBindTemporaryExprClass: {
+      S = cast<CXXBindTemporaryExpr>(S)->getSubExpr();
+      break;
+    }
+    case Stmt::UnaryExprOrTypeTraitExprClass: {
+      // No need to unconditionally visit subexpressions.
+      return;
+    }
+  }
+  
+  for (Stmt::child_iterator it = S->child_begin(), ei = S->child_end();
+       it != ei; ++it) {
+    if (Stmt *child = *it)
+      AddLiveStmt(val.liveStmts, LV.SSetFact, child);
+  }
+}
+
+void TransferFunctions::VisitBinaryOperator(BinaryOperator *B) {
+  if (B->isAssignmentOp()) {
+    if (!LV.killAtAssign)
+      return;
+    
+    // Assigning to a variable?
+    Expr *LHS = B->getLHS()->IgnoreParens();
+    
+    if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS))
+      if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+        // Assignments to references don't kill the ref's address
+        if (VD->getType()->isReferenceType())
+          return;
+
+        if (!isAlwaysAlive(VD)) {
+          // The variable is now dead.
+          val.liveDecls = LV.DSetFact.remove(val.liveDecls, VD);
+        }
+
+        if (observer)
+          observer->observerKill(DR);
+      }
+  }
+}
+
+void TransferFunctions::VisitBlockExpr(BlockExpr *BE) {
+  AnalysisDeclContext::referenced_decls_iterator I, E;
+  llvm::tie(I, E) =
+    LV.analysisContext.getReferencedBlockVars(BE->getBlockDecl());
+  for ( ; I != E ; ++I) {
+    const VarDecl *VD = *I;
+    if (isAlwaysAlive(VD))
+      continue;
+    val.liveDecls = LV.DSetFact.add(val.liveDecls, VD);
+  }
+}
+
+void TransferFunctions::VisitDeclRefExpr(DeclRefExpr *DR) {
+  if (const VarDecl *D = dyn_cast<VarDecl>(DR->getDecl()))
+    if (!isAlwaysAlive(D) && LV.inAssignment.find(DR) == LV.inAssignment.end())
+      val.liveDecls = LV.DSetFact.add(val.liveDecls, D);
+}
+
+void TransferFunctions::VisitDeclStmt(DeclStmt *DS) {
+  for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE = DS->decl_end();
+       DI != DE; ++DI)
+    if (VarDecl *VD = dyn_cast<VarDecl>(*DI)) {
+      if (!isAlwaysAlive(VD))
+        val.liveDecls = LV.DSetFact.remove(val.liveDecls, VD);
+    }
+}
+
+void TransferFunctions::VisitObjCForCollectionStmt(ObjCForCollectionStmt *OS) {
+  // Kill the iteration variable.
+  DeclRefExpr *DR = 0;
+  const VarDecl *VD = 0;
+
+  Stmt *element = OS->getElement();
+  if (DeclStmt *DS = dyn_cast<DeclStmt>(element)) {
+    VD = cast<VarDecl>(DS->getSingleDecl());
+  }
+  else if ((DR = dyn_cast<DeclRefExpr>(cast<Expr>(element)->IgnoreParens()))) {
+    VD = cast<VarDecl>(DR->getDecl());
+  }
+  
+  if (VD) {
+    val.liveDecls = LV.DSetFact.remove(val.liveDecls, VD);
+    if (observer && DR)
+      observer->observerKill(DR);
+  }
+}
+
+void TransferFunctions::
+VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *UE)
+{
+  // While sizeof(var) doesn't technically extend the liveness of 'var', it
+  // does extent the liveness of metadata if 'var' is a VariableArrayType.
+  // We handle that special case here.
+  if (UE->getKind() != UETT_SizeOf || UE->isArgumentType())
+    return;
+
+  const Expr *subEx = UE->getArgumentExpr();
+  if (subEx->getType()->isVariableArrayType()) {
+    assert(subEx->isLValue());
+    val.liveStmts = LV.SSetFact.add(val.liveStmts, subEx->IgnoreParens());
+  }
+}
+
+void TransferFunctions::VisitUnaryOperator(UnaryOperator *UO) {
+  // Treat ++/-- as a kill.
+  // Note we don't actually have to do anything if we don't have an observer,
+  // since a ++/-- acts as both a kill and a "use".
+  if (!observer)
+    return;
+  
+  switch (UO->getOpcode()) {
+  default:
+    return;
+  case UO_PostInc:
+  case UO_PostDec:    
+  case UO_PreInc:
+  case UO_PreDec:
+    break;
+  }
+  
+  if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(UO->getSubExpr()->IgnoreParens()))
+    if (isa<VarDecl>(DR->getDecl())) {
+      // Treat ++/-- as a kill.
+      observer->observerKill(DR);
+    }
+}
+
+LiveVariables::LivenessValues
+LiveVariablesImpl::runOnBlock(const CFGBlock *block,
+                              LiveVariables::LivenessValues val,
+                              LiveVariables::Observer *obs) {
+
+  TransferFunctions TF(*this, val, obs, block);
+  
+  // Visit the terminator (if any).
+  if (const Stmt *term = block->getTerminator())
+    TF.Visit(const_cast<Stmt*>(term));
+  
+  // Apply the transfer function for all Stmts in the block.
+  for (CFGBlock::const_reverse_iterator it = block->rbegin(),
+       ei = block->rend(); it != ei; ++it) {
+    const CFGElement &elem = *it;
+    if (!isa<CFGStmt>(elem))
+      continue;
+    
+    const Stmt *S = cast<CFGStmt>(elem).getStmt();
+    TF.Visit(const_cast<Stmt*>(S));
+    stmtsToLiveness[S] = val;
+  }
+  return val;
+}
+
+void LiveVariables::runOnAllBlocks(LiveVariables::Observer &obs) {
+  const CFG *cfg = getImpl(impl).analysisContext.getCFG();
+  for (CFG::const_iterator it = cfg->begin(), ei = cfg->end(); it != ei; ++it)
+    getImpl(impl).runOnBlock(*it, getImpl(impl).blocksEndToLiveness[*it], &obs);    
+}
+
+LiveVariables::LiveVariables(void *im) : impl(im) {} 
+
+LiveVariables::~LiveVariables() {
+  delete (LiveVariablesImpl*) impl;
+}
+
+LiveVariables *
+LiveVariables::computeLiveness(AnalysisDeclContext &AC,
+                                 bool killAtAssign) {
+
+  // No CFG?  Bail out.
+  CFG *cfg = AC.getCFG();
+  if (!cfg)
+    return 0;
+
+  LiveVariablesImpl *LV = new LiveVariablesImpl(AC, killAtAssign);
+
+  // Construct the dataflow worklist.  Enqueue the exit block as the
+  // start of the analysis.
+  DataflowWorklist worklist(*cfg, AC);
+  llvm::BitVector everAnalyzedBlock(cfg->getNumBlockIDs());
+
+  // FIXME: we should enqueue using post order.
+  for (CFG::const_iterator it = cfg->begin(), ei = cfg->end(); it != ei; ++it) {
+    const CFGBlock *block = *it;
+    worklist.enqueueBlock(block);
+    
+    // FIXME: Scan for DeclRefExprs using in the LHS of an assignment.
+    // We need to do this because we lack context in the reverse analysis
+    // to determine if a DeclRefExpr appears in such a context, and thus
+    // doesn't constitute a "use".
+    if (killAtAssign)
+      for (CFGBlock::const_iterator bi = block->begin(), be = block->end();
+           bi != be; ++bi) {
+        if (const CFGStmt *cs = bi->getAs<CFGStmt>()) {
+          if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(cs->getStmt())) {
+            if (BO->getOpcode() == BO_Assign) {
+              if (const DeclRefExpr *DR =
+                    dyn_cast<DeclRefExpr>(BO->getLHS()->IgnoreParens())) {
+                LV->inAssignment[DR] = 1;
+              }
+            }
+          }
+        }
+      }
+  }
+  
+  worklist.sortWorklist();
+  
+  while (const CFGBlock *block = worklist.dequeue()) {
+    // Determine if the block's end value has changed.  If not, we
+    // have nothing left to do for this block.
+    LivenessValues &prevVal = LV->blocksEndToLiveness[block];
+    
+    // Merge the values of all successor blocks.
+    LivenessValues val;
+    for (CFGBlock::const_succ_iterator it = block->succ_begin(),
+                                       ei = block->succ_end(); it != ei; ++it) {
+      if (const CFGBlock *succ = *it) {     
+        val = LV->merge(val, LV->blocksBeginToLiveness[succ]);
+      }
+    }
+    
+    if (!everAnalyzedBlock[block->getBlockID()])
+      everAnalyzedBlock[block->getBlockID()] = true;
+    else if (prevVal.equals(val))
+      continue;
+
+    prevVal = val;
+    
+    // Update the dataflow value for the start of this block.
+    LV->blocksBeginToLiveness[block] = LV->runOnBlock(block, val);
+    
+    // Enqueue the value to the predecessors.
+    worklist.enqueuePredecessors(block);
+  }
+  
+  return new LiveVariables(LV);
+}
+
+static bool compare_entries(const CFGBlock *A, const CFGBlock *B) {
+  return A->getBlockID() < B->getBlockID();
+}
+
+static bool compare_vd_entries(const Decl *A, const Decl *B) {
+  SourceLocation ALoc = A->getLocStart();
+  SourceLocation BLoc = B->getLocStart();
+  return ALoc.getRawEncoding() < BLoc.getRawEncoding();
+}
+
+void LiveVariables::dumpBlockLiveness(const SourceManager &M) {
+  getImpl(impl).dumpBlockLiveness(M);
+}
+
+void LiveVariablesImpl::dumpBlockLiveness(const SourceManager &M) {
+  std::vector<const CFGBlock *> vec;
+  for (llvm::DenseMap<const CFGBlock *, LiveVariables::LivenessValues>::iterator
+       it = blocksEndToLiveness.begin(), ei = blocksEndToLiveness.end();
+       it != ei; ++it) {
+    vec.push_back(it->first);    
+  }
+  std::sort(vec.begin(), vec.end(), compare_entries);
+
+  std::vector<const VarDecl*> declVec;
+
+  for (std::vector<const CFGBlock *>::iterator
+        it = vec.begin(), ei = vec.end(); it != ei; ++it) {
+    llvm::errs() << "\n[ B" << (*it)->getBlockID()
+                 << " (live variables at block exit) ]\n";
+    
+    LiveVariables::LivenessValues vals = blocksEndToLiveness[*it];
+    declVec.clear();
+    
+    for (llvm::ImmutableSet<const VarDecl *>::iterator si =
+          vals.liveDecls.begin(),
+          se = vals.liveDecls.end(); si != se; ++si) {
+      declVec.push_back(*si);      
+    }
+    
+    std::sort(declVec.begin(), declVec.end(), compare_vd_entries);
+    
+    for (std::vector<const VarDecl*>::iterator di = declVec.begin(),
+         de = declVec.end(); di != de; ++di) {
+      llvm::errs() << " " << (*di)->getDeclName().getAsString()
+                   << " <";
+      (*di)->getLocation().dump(M);
+      llvm::errs() << ">\n";
+    }
+  }
+  llvm::errs() << "\n";  
+}
+
+const void *LiveVariables::getTag() { static int x; return &x; }
+const void *RelaxedLiveVariables::getTag() { static int x; return &x; }
diff --git a/clang/lib/Analysis/Makefile b/clang/lib/Analysis/Makefile
new file mode 100644
index 0000000..fbbb83d
--- /dev/null
+++ b/clang/lib/Analysis/Makefile
@@ -0,0 +1,18 @@
+##===- clang/lib/Analysis/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+#
+# This implements analyses built on top of source-level CFGs. 
+#
+##===----------------------------------------------------------------------===##
+
+CLANG_LEVEL := ../..
+LIBRARYNAME := clangAnalysis
+
+include $(CLANG_LEVEL)/Makefile
+
diff --git a/clang/lib/Analysis/PostOrderCFGView.cpp b/clang/lib/Analysis/PostOrderCFGView.cpp
new file mode 100644
index 0000000..cfd66f7
--- /dev/null
+++ b/clang/lib/Analysis/PostOrderCFGView.cpp
@@ -0,0 +1,49 @@
+//===- PostOrderCFGView.cpp - Post order view of CFG blocks -------*- C++ --*-//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements post order view of the blocks in a CFG.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/PostOrderCFGView.h"
+
+using namespace clang;
+
+void PostOrderCFGView::anchor() { }
+
+PostOrderCFGView::PostOrderCFGView(const CFG *cfg) {
+  Blocks.reserve(cfg->getNumBlockIDs());
+  CFGBlockSet BSet(cfg);
+    
+  for (po_iterator I = po_iterator::begin(cfg, BSet),
+                   E = po_iterator::end(cfg, BSet); I != E; ++I) {
+    BlockOrder[*I] = Blocks.size() + 1;
+    Blocks.push_back(*I);      
+  }
+}
+
+PostOrderCFGView *PostOrderCFGView::create(AnalysisDeclContext &ctx) {
+  const CFG *cfg = ctx.getCFG();
+  if (!cfg)
+    return 0;
+  return new PostOrderCFGView(cfg);
+}
+
+const void *PostOrderCFGView::getTag() { static int x; return &x; }
+
+bool PostOrderCFGView::BlockOrderCompare::operator()(const CFGBlock *b1,
+                                                     const CFGBlock *b2) const {
+  PostOrderCFGView::BlockOrderTy::const_iterator b1It = POV.BlockOrder.find(b1);
+  PostOrderCFGView::BlockOrderTy::const_iterator b2It = POV.BlockOrder.find(b2);
+    
+  unsigned b1V = (b1It == POV.BlockOrder.end()) ? 0 : b1It->second;
+  unsigned b2V = (b2It == POV.BlockOrder.end()) ? 0 : b2It->second;
+  return b1V > b2V;
+}
+
diff --git a/clang/lib/Analysis/PrintfFormatString.cpp b/clang/lib/Analysis/PrintfFormatString.cpp
new file mode 100644
index 0000000..e1049b3
--- /dev/null
+++ b/clang/lib/Analysis/PrintfFormatString.cpp
@@ -0,0 +1,669 @@
+//== PrintfFormatString.cpp - Analysis of printf format strings --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Handling of format string in printf and friends.  The structure of format
+// strings for fprintf() are described in C99 7.19.6.1.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/FormatString.h"
+#include "FormatStringParsing.h"
+
+using clang::analyze_format_string::ArgTypeResult;
+using clang::analyze_format_string::FormatStringHandler;
+using clang::analyze_format_string::LengthModifier;
+using clang::analyze_format_string::OptionalAmount;
+using clang::analyze_format_string::ConversionSpecifier;
+using clang::analyze_printf::PrintfSpecifier;
+
+using namespace clang;
+
+typedef clang::analyze_format_string::SpecifierResult<PrintfSpecifier>
+        PrintfSpecifierResult;
+
+//===----------------------------------------------------------------------===//
+// Methods for parsing format strings.
+//===----------------------------------------------------------------------===//
+
+using analyze_format_string::ParseNonPositionAmount;
+
+static bool ParsePrecision(FormatStringHandler &H, PrintfSpecifier &FS,
+                           const char *Start, const char *&Beg, const char *E,
+                           unsigned *argIndex) {
+  if (argIndex) {
+    FS.setPrecision(ParseNonPositionAmount(Beg, E, *argIndex));
+  } else {
+    const OptionalAmount Amt = ParsePositionAmount(H, Start, Beg, E,
+                                           analyze_format_string::PrecisionPos);
+    if (Amt.isInvalid())
+      return true;
+    FS.setPrecision(Amt);
+  }
+  return false;
+}
+
+static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
+                                                  const char *&Beg,
+                                                  const char *E,
+                                                  unsigned &argIndex,
+                                                  const LangOptions &LO) {
+
+  using namespace clang::analyze_format_string;
+  using namespace clang::analyze_printf;
+
+  const char *I = Beg;
+  const char *Start = 0;
+  UpdateOnReturn <const char*> UpdateBeg(Beg, I);
+
+  // Look for a '%' character that indicates the start of a format specifier.
+  for ( ; I != E ; ++I) {
+    char c = *I;
+    if (c == '\0') {
+      // Detect spurious null characters, which are likely errors.
+      H.HandleNullChar(I);
+      return true;
+    }
+    if (c == '%') {
+      Start = I++;  // Record the start of the format specifier.
+      break;
+    }
+  }
+
+  // No format specifier found?
+  if (!Start)
+    return false;
+
+  if (I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  PrintfSpecifier FS;
+  if (ParseArgPosition(H, FS, Start, I, E))
+    return true;
+
+  if (I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  // Look for flags (if any).
+  bool hasMore = true;
+  for ( ; I != E; ++I) {
+    switch (*I) {
+      default: hasMore = false; break;
+      case '\'':
+        // FIXME: POSIX specific.  Always accept?
+        FS.setHasThousandsGrouping(I);
+        break;
+      case '-': FS.setIsLeftJustified(I); break;
+      case '+': FS.setHasPlusPrefix(I); break;
+      case ' ': FS.setHasSpacePrefix(I); break;
+      case '#': FS.setHasAlternativeForm(I); break;
+      case '0': FS.setHasLeadingZeros(I); break;
+    }
+    if (!hasMore)
+      break;
+  }
+
+  if (I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  // Look for the field width (if any).
+  if (ParseFieldWidth(H, FS, Start, I, E,
+                      FS.usesPositionalArg() ? 0 : &argIndex))
+    return true;
+
+  if (I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  // Look for the precision (if any).
+  if (*I == '.') {
+    ++I;
+    if (I == E) {
+      H.HandleIncompleteSpecifier(Start, E - Start);
+      return true;
+    }
+
+    if (ParsePrecision(H, FS, Start, I, E,
+                       FS.usesPositionalArg() ? 0 : &argIndex))
+      return true;
+
+    if (I == E) {
+      // No more characters left?
+      H.HandleIncompleteSpecifier(Start, E - Start);
+      return true;
+    }
+  }
+
+  // Look for the length modifier.
+  if (ParseLengthModifier(FS, I, E, LO) && I == E) {
+    // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+
+  if (*I == '\0') {
+    // Detect spurious null characters, which are likely errors.
+    H.HandleNullChar(I);
+    return true;
+  }
+
+  // Finally, look for the conversion specifier.
+  const char *conversionPosition = I++;
+  ConversionSpecifier::Kind k = ConversionSpecifier::InvalidSpecifier;
+  switch (*conversionPosition) {
+    default:
+      break;
+    // C99: 7.19.6.1 (section 8).
+    case '%': k = ConversionSpecifier::PercentArg;   break;
+    case 'A': k = ConversionSpecifier::AArg; break;
+    case 'E': k = ConversionSpecifier::EArg; break;
+    case 'F': k = ConversionSpecifier::FArg; break;
+    case 'G': k = ConversionSpecifier::GArg; break;
+    case 'X': k = ConversionSpecifier::XArg; break;
+    case 'a': k = ConversionSpecifier::aArg; break;
+    case 'c': k = ConversionSpecifier::cArg; break;
+    case 'd': k = ConversionSpecifier::dArg; break;
+    case 'e': k = ConversionSpecifier::eArg; break;
+    case 'f': k = ConversionSpecifier::fArg; break;
+    case 'g': k = ConversionSpecifier::gArg; break;
+    case 'i': k = ConversionSpecifier::iArg; break;
+    case 'n': k = ConversionSpecifier::nArg; break;
+    case 'o': k = ConversionSpecifier::oArg; break;
+    case 'p': k = ConversionSpecifier::pArg;   break;
+    case 's': k = ConversionSpecifier::sArg;      break;
+    case 'u': k = ConversionSpecifier::uArg; break;
+    case 'x': k = ConversionSpecifier::xArg; break;
+    // POSIX specific.
+    case 'C': k = ConversionSpecifier::CArg; break;
+    case 'S': k = ConversionSpecifier::SArg; break;
+    // Objective-C.
+    case '@': k = ConversionSpecifier::ObjCObjArg; break;
+    // Glibc specific.
+    case 'm': k = ConversionSpecifier::PrintErrno; break;
+  }
+  PrintfConversionSpecifier CS(conversionPosition, k);
+  FS.setConversionSpecifier(CS);
+  if (CS.consumesDataArgument() && !FS.usesPositionalArg())
+    FS.setArgIndex(argIndex++);
+
+  if (k == ConversionSpecifier::InvalidSpecifier) {
+    // Assume the conversion takes one argument.
+    return !H.HandleInvalidPrintfConversionSpecifier(FS, Start, I - Start);
+  }
+  return PrintfSpecifierResult(Start, FS);
+}
+
+bool clang::analyze_format_string::ParsePrintfString(FormatStringHandler &H,
+                                                     const char *I,
+                                                     const char *E,
+                                                     const LangOptions &LO) {
+
+  unsigned argIndex = 0;
+
+  // Keep looking for a format specifier until we have exhausted the string.
+  while (I != E) {
+    const PrintfSpecifierResult &FSR = ParsePrintfSpecifier(H, I, E, argIndex,
+                                                            LO);
+    // Did a fail-stop error of any kind occur when parsing the specifier?
+    // If so, don't do any more processing.
+    if (FSR.shouldStop())
+      return true;;
+    // Did we exhaust the string or encounter an error that
+    // we can recover from?
+    if (!FSR.hasValue())
+      continue;
+    // We have a format specifier.  Pass it to the callback.
+    if (!H.HandlePrintfSpecifier(FSR.getValue(), FSR.getStart(),
+                                 I - FSR.getStart()))
+      return true;
+  }
+  assert(I == E && "Format string not exhausted");
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// Methods on PrintfSpecifier.
+//===----------------------------------------------------------------------===//
+
+ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx,
+                                          bool IsObjCLiteral) const {
+  const PrintfConversionSpecifier &CS = getConversionSpecifier();
+
+  if (!CS.consumesDataArgument())
+    return ArgTypeResult::Invalid();
+
+  if (CS.getKind() == ConversionSpecifier::cArg)
+    switch (LM.getKind()) {
+      case LengthModifier::None: return Ctx.IntTy;
+      case LengthModifier::AsLong:
+        return ArgTypeResult(ArgTypeResult::WIntTy, "wint_t");
+      default:
+        return ArgTypeResult::Invalid();
+    }
+
+  if (CS.isIntArg())
+    switch (LM.getKind()) {
+      case LengthModifier::AsLongDouble:
+        // GNU extension.
+        return Ctx.LongLongTy;
+      case LengthModifier::None: return Ctx.IntTy;
+      case LengthModifier::AsChar: return ArgTypeResult::AnyCharTy;
+      case LengthModifier::AsShort: return Ctx.ShortTy;
+      case LengthModifier::AsLong: return Ctx.LongTy;
+      case LengthModifier::AsLongLong:
+      case LengthModifier::AsQuad:
+        return Ctx.LongLongTy;
+      case LengthModifier::AsIntMax:
+        return ArgTypeResult(Ctx.getIntMaxType(), "intmax_t");
+      case LengthModifier::AsSizeT:
+        // FIXME: How to get the corresponding signed version of size_t?
+        return ArgTypeResult();
+      case LengthModifier::AsPtrDiff:
+        return ArgTypeResult(Ctx.getPointerDiffType(), "ptrdiff_t");
+      case LengthModifier::AsAllocate:
+      case LengthModifier::AsMAllocate:
+        return ArgTypeResult::Invalid();
+    }
+
+  if (CS.isUIntArg())
+    switch (LM.getKind()) {
+      case LengthModifier::AsLongDouble:
+        // GNU extension.
+        return Ctx.UnsignedLongLongTy;
+      case LengthModifier::None: return Ctx.UnsignedIntTy;
+      case LengthModifier::AsChar: return Ctx.UnsignedCharTy;
+      case LengthModifier::AsShort: return Ctx.UnsignedShortTy;
+      case LengthModifier::AsLong: return Ctx.UnsignedLongTy;
+      case LengthModifier::AsLongLong:
+      case LengthModifier::AsQuad:
+        return Ctx.UnsignedLongLongTy;
+      case LengthModifier::AsIntMax:
+        return ArgTypeResult(Ctx.getUIntMaxType(), "uintmax_t");
+      case LengthModifier::AsSizeT:
+        return ArgTypeResult(Ctx.getSizeType(), "size_t");
+      case LengthModifier::AsPtrDiff:
+        // FIXME: How to get the corresponding unsigned
+        // version of ptrdiff_t?
+        return ArgTypeResult();
+      case LengthModifier::AsAllocate:
+      case LengthModifier::AsMAllocate:
+        return ArgTypeResult::Invalid();
+    }
+
+  if (CS.isDoubleArg()) {
+    if (LM.getKind() == LengthModifier::AsLongDouble)
+      return Ctx.LongDoubleTy;
+    return Ctx.DoubleTy;
+  }
+
+  switch (CS.getKind()) {
+    case ConversionSpecifier::sArg:
+      if (LM.getKind() == LengthModifier::AsWideChar) {
+        if (IsObjCLiteral)
+          return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst());
+        return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *");
+      }
+      return ArgTypeResult::CStrTy;
+    case ConversionSpecifier::SArg:
+      if (IsObjCLiteral)
+        return Ctx.getPointerType(Ctx.UnsignedShortTy.withConst());
+      return ArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t *");
+    case ConversionSpecifier::CArg:
+      if (IsObjCLiteral)
+        return Ctx.UnsignedShortTy;
+      return ArgTypeResult(Ctx.WCharTy, "wchar_t");
+    case ConversionSpecifier::pArg:
+      return ArgTypeResult::CPointerTy;
+    case ConversionSpecifier::ObjCObjArg:
+      return ArgTypeResult::ObjCPointerTy;
+    default:
+      break;
+  }
+
+  // FIXME: Handle other cases.
+  return ArgTypeResult();
+}
+
+bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
+                              ASTContext &Ctx, bool IsObjCLiteral) {
+  // Handle strings first (char *, wchar_t *)
+  if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) {
+    CS.setKind(ConversionSpecifier::sArg);
+
+    // Disable irrelevant flags
+    HasAlternativeForm = 0;
+    HasLeadingZeroes = 0;
+
+    // Set the long length modifier for wide characters
+    if (QT->getPointeeType()->isWideCharType())
+      LM.setKind(LengthModifier::AsWideChar);
+    else
+      LM.setKind(LengthModifier::None);
+
+    return true;
+  }
+
+  // We can only work with builtin types.
+  const BuiltinType *BT = QT->getAs<BuiltinType>();
+  if (!BT)
+    return false;
+
+  // Set length modifier
+  switch (BT->getKind()) {
+  case BuiltinType::Bool:
+  case BuiltinType::WChar_U:
+  case BuiltinType::WChar_S:
+  case BuiltinType::Char16:
+  case BuiltinType::Char32:
+  case BuiltinType::UInt128:
+  case BuiltinType::Int128:
+  case BuiltinType::Half:
+    // Various types which are non-trivial to correct.
+    return false;
+
+#define SIGNED_TYPE(Id, SingletonId)
+#define UNSIGNED_TYPE(Id, SingletonId)
+#define FLOATING_TYPE(Id, SingletonId)
+#define BUILTIN_TYPE(Id, SingletonId) \
+  case BuiltinType::Id:
+#include "clang/AST/BuiltinTypes.def"
+    // Misc other stuff which doesn't make sense here.
+    return false;
+
+  case BuiltinType::UInt:
+  case BuiltinType::Int:
+  case BuiltinType::Float:
+  case BuiltinType::Double:
+    LM.setKind(LengthModifier::None);
+    break;
+
+  case BuiltinType::Char_U:
+  case BuiltinType::UChar:
+  case BuiltinType::Char_S:
+  case BuiltinType::SChar:
+    LM.setKind(LengthModifier::AsChar);
+    break;
+
+  case BuiltinType::Short:
+  case BuiltinType::UShort:
+    LM.setKind(LengthModifier::AsShort);
+    break;
+
+  case BuiltinType::Long:
+  case BuiltinType::ULong:
+    LM.setKind(LengthModifier::AsLong);
+    break;
+
+  case BuiltinType::LongLong:
+  case BuiltinType::ULongLong:
+    LM.setKind(LengthModifier::AsLongLong);
+    break;
+
+  case BuiltinType::LongDouble:
+    LM.setKind(LengthModifier::AsLongDouble);
+    break;
+  }
+
+  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.
+  if (isa<TypedefType>(QT) && (LangOpt.C99 || LangOpt.CPlusPlus0x)) {
+    const IdentifierInfo *Identifier = QT.getBaseTypeIdentifier();
+    if (Identifier->getName() == "size_t") {
+      LM.setKind(LengthModifier::AsSizeT);
+    } else if (Identifier->getName() == "ssize_t") {
+      // Not C99, but common in Unix.
+      LM.setKind(LengthModifier::AsSizeT);
+    } else if (Identifier->getName() == "intmax_t") {
+      LM.setKind(LengthModifier::AsIntMax);
+    } else if (Identifier->getName() == "uintmax_t") {
+      LM.setKind(LengthModifier::AsIntMax);
+    } else if (Identifier->getName() == "ptrdiff_t") {
+      LM.setKind(LengthModifier::AsPtrDiff);
+    }
+  }
+
+  // If fixing the length modifier was enough, we are done.
+  const analyze_printf::ArgTypeResult &ATR = getArgType(Ctx, IsObjCLiteral);
+  if (hasValidLengthModifier() && ATR.isValid() && ATR.matchesType(Ctx, QT))
+    return true;
+
+  // Set conversion specifier and disable any flags which do not apply to it.
+  // Let typedefs to char fall through to int, as %c is silly for uint8_t.
+  if (isa<TypedefType>(QT) && QT->isAnyCharacterType()) {
+    CS.setKind(ConversionSpecifier::cArg);
+    LM.setKind(LengthModifier::None);
+    Precision.setHowSpecified(OptionalAmount::NotSpecified);
+    HasAlternativeForm = 0;
+    HasLeadingZeroes = 0;
+    HasPlusPrefix = 0;
+  }
+  // Test for Floating type first as LongDouble can pass isUnsignedIntegerType
+  else if (QT->isRealFloatingType()) {
+    CS.setKind(ConversionSpecifier::fArg);
+  }
+  else if (QT->isSignedIntegerType()) {
+    CS.setKind(ConversionSpecifier::dArg);
+    HasAlternativeForm = 0;
+  }
+  else if (QT->isUnsignedIntegerType()) {
+    CS.setKind(ConversionSpecifier::uArg);
+    HasAlternativeForm = 0;
+    HasPlusPrefix = 0;
+  } else {
+    llvm_unreachable("Unexpected type");
+  }
+
+  return true;
+}
+
+void PrintfSpecifier::toString(raw_ostream &os) const {
+  // Whilst some features have no defined order, we are using the order
+  // appearing in the C99 standard (ISO/IEC 9899:1999 (E) 7.19.6.1)
+  os << "%";
+
+  // Positional args
+  if (usesPositionalArg()) {
+    os << getPositionalArgIndex() << "$";
+  }
+
+  // Conversion flags
+  if (IsLeftJustified)    os << "-";
+  if (HasPlusPrefix)      os << "+";
+  if (HasSpacePrefix)     os << " ";
+  if (HasAlternativeForm) os << "#";
+  if (HasLeadingZeroes)   os << "0";
+
+  // Minimum field width
+  FieldWidth.toString(os);
+  // Precision
+  Precision.toString(os);
+  // Length modifier
+  os << LM.toString();
+  // Conversion specifier
+  os << CS.toString();
+}
+
+bool PrintfSpecifier::hasValidPlusPrefix() const {
+  if (!HasPlusPrefix)
+    return true;
+
+  // The plus prefix only makes sense for signed conversions
+  switch (CS.getKind()) {
+  case ConversionSpecifier::dArg:
+  case ConversionSpecifier::iArg:
+  case ConversionSpecifier::fArg:
+  case ConversionSpecifier::FArg:
+  case ConversionSpecifier::eArg:
+  case ConversionSpecifier::EArg:
+  case ConversionSpecifier::gArg:
+  case ConversionSpecifier::GArg:
+  case ConversionSpecifier::aArg:
+  case ConversionSpecifier::AArg:
+    return true;
+
+  default:
+    return false;
+  }
+}
+
+bool PrintfSpecifier::hasValidAlternativeForm() const {
+  if (!HasAlternativeForm)
+    return true;
+
+  // Alternate form flag only valid with the oxXaAeEfFgG conversions
+  switch (CS.getKind()) {
+  case ConversionSpecifier::oArg:
+  case ConversionSpecifier::xArg:
+  case ConversionSpecifier::XArg:
+  case ConversionSpecifier::aArg:
+  case ConversionSpecifier::AArg:
+  case ConversionSpecifier::eArg:
+  case ConversionSpecifier::EArg:
+  case ConversionSpecifier::fArg:
+  case ConversionSpecifier::FArg:
+  case ConversionSpecifier::gArg:
+  case ConversionSpecifier::GArg:
+    return true;
+
+  default:
+    return false;
+  }
+}
+
+bool PrintfSpecifier::hasValidLeadingZeros() const {
+  if (!HasLeadingZeroes)
+    return true;
+
+  // Leading zeroes flag only valid with the diouxXaAeEfFgG conversions
+  switch (CS.getKind()) {
+  case ConversionSpecifier::dArg:
+  case ConversionSpecifier::iArg:
+  case ConversionSpecifier::oArg:
+  case ConversionSpecifier::uArg:
+  case ConversionSpecifier::xArg:
+  case ConversionSpecifier::XArg:
+  case ConversionSpecifier::aArg:
+  case ConversionSpecifier::AArg:
+  case ConversionSpecifier::eArg:
+  case ConversionSpecifier::EArg:
+  case ConversionSpecifier::fArg:
+  case ConversionSpecifier::FArg:
+  case ConversionSpecifier::gArg:
+  case ConversionSpecifier::GArg:
+    return true;
+
+  default:
+    return false;
+  }
+}
+
+bool PrintfSpecifier::hasValidSpacePrefix() const {
+  if (!HasSpacePrefix)
+    return true;
+
+  // The space prefix only makes sense for signed conversions
+  switch (CS.getKind()) {
+  case ConversionSpecifier::dArg:
+  case ConversionSpecifier::iArg:
+  case ConversionSpecifier::fArg:
+  case ConversionSpecifier::FArg:
+  case ConversionSpecifier::eArg:
+  case ConversionSpecifier::EArg:
+  case ConversionSpecifier::gArg:
+  case ConversionSpecifier::GArg:
+  case ConversionSpecifier::aArg:
+  case ConversionSpecifier::AArg:
+    return true;
+
+  default:
+    return false;
+  }
+}
+
+bool PrintfSpecifier::hasValidLeftJustified() const {
+  if (!IsLeftJustified)
+    return true;
+
+  // The left justified flag is valid for all conversions except n
+  switch (CS.getKind()) {
+  case ConversionSpecifier::nArg:
+    return false;
+
+  default:
+    return true;
+  }
+}
+
+bool PrintfSpecifier::hasValidThousandsGroupingPrefix() const {
+  if (!HasThousandsGrouping)
+    return true;
+
+  switch (CS.getKind()) {
+    case ConversionSpecifier::dArg:
+    case ConversionSpecifier::iArg:
+    case ConversionSpecifier::uArg:
+    case ConversionSpecifier::fArg:
+    case ConversionSpecifier::FArg:
+    case ConversionSpecifier::gArg:
+    case ConversionSpecifier::GArg:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool PrintfSpecifier::hasValidPrecision() const {
+  if (Precision.getHowSpecified() == OptionalAmount::NotSpecified)
+    return true;
+
+  // Precision is only valid with the diouxXaAeEfFgGs conversions
+  switch (CS.getKind()) {
+  case ConversionSpecifier::dArg:
+  case ConversionSpecifier::iArg:
+  case ConversionSpecifier::oArg:
+  case ConversionSpecifier::uArg:
+  case ConversionSpecifier::xArg:
+  case ConversionSpecifier::XArg:
+  case ConversionSpecifier::aArg:
+  case ConversionSpecifier::AArg:
+  case ConversionSpecifier::eArg:
+  case ConversionSpecifier::EArg:
+  case ConversionSpecifier::fArg:
+  case ConversionSpecifier::FArg:
+  case ConversionSpecifier::gArg:
+  case ConversionSpecifier::GArg:
+  case ConversionSpecifier::sArg:
+    return true;
+
+  default:
+    return false;
+  }
+}
+bool PrintfSpecifier::hasValidFieldWidth() const {
+  if (FieldWidth.getHowSpecified() == OptionalAmount::NotSpecified)
+      return true;
+
+  // The field width is valid for all conversions except n
+  switch (CS.getKind()) {
+  case ConversionSpecifier::nArg:
+    return false;
+
+  default:
+    return true;
+  }
+}
diff --git a/clang/lib/Analysis/ProgramPoint.cpp b/clang/lib/Analysis/ProgramPoint.cpp
new file mode 100644
index 0000000..3f711b4
--- /dev/null
+++ b/clang/lib/Analysis/ProgramPoint.cpp
@@ -0,0 +1,49 @@
+//==- ProgramPoint.cpp - Program Points for Path-Sensitive Analysis -*- C++ -*-/
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the interface ProgramPoint, which identifies a
+//  distinct location in a function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/ProgramPoint.h"
+
+using namespace clang;
+
+ProgramPointTag::~ProgramPointTag() {}
+
+ProgramPoint ProgramPoint::getProgramPoint(const Stmt *S, ProgramPoint::Kind K,
+                                           const LocationContext *LC,
+                                           const ProgramPointTag *tag){
+  switch (K) {
+    default:
+      llvm_unreachable("Unhandled ProgramPoint kind");
+    case ProgramPoint::PreStmtKind:
+      return PreStmt(S, LC, tag);
+    case ProgramPoint::PostStmtKind:
+      return PostStmt(S, LC, tag);
+    case ProgramPoint::PreLoadKind:
+      return PreLoad(S, LC, tag);
+    case ProgramPoint::PostLoadKind:
+      return PostLoad(S, LC, tag);
+    case ProgramPoint::PreStoreKind:
+      return PreStore(S, LC, tag);
+    case ProgramPoint::PostLValueKind:
+      return PostLValue(S, LC, tag);
+    case ProgramPoint::PostPurgeDeadSymbolsKind:
+      return PostPurgeDeadSymbols(S, LC, tag);
+  }
+}
+
+SimpleProgramPointTag::SimpleProgramPointTag(StringRef description)
+  : desc(description) {}
+
+StringRef SimpleProgramPointTag::getTagDescription() const {
+  return desc;
+}
diff --git a/clang/lib/Analysis/PseudoConstantAnalysis.cpp b/clang/lib/Analysis/PseudoConstantAnalysis.cpp
new file mode 100644
index 0000000..c8b491a
--- /dev/null
+++ b/clang/lib/Analysis/PseudoConstantAnalysis.cpp
@@ -0,0 +1,227 @@
+//== PseudoConstantAnalysis.cpp - Find Pseudoconstants in the AST-*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file tracks the usage of variables in a Decl body to see if they are
+// never written to, implying that they constant. This is useful in static
+// analysis to see if a developer might have intended a variable to be const.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/PseudoConstantAnalysis.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/Stmt.h"
+#include <deque>
+
+using namespace clang;
+
+// The number of ValueDecls we want to keep track of by default (per-function)
+#define VARDECL_SET_SIZE 256
+typedef llvm::SmallPtrSet<const VarDecl*, VARDECL_SET_SIZE> VarDeclSet;
+
+PseudoConstantAnalysis::PseudoConstantAnalysis(const Stmt *DeclBody) :
+      DeclBody(DeclBody), Analyzed(false) {
+  NonConstantsImpl = new VarDeclSet;
+  UsedVarsImpl = new VarDeclSet;
+}
+
+PseudoConstantAnalysis::~PseudoConstantAnalysis() {
+  delete (VarDeclSet*)NonConstantsImpl;
+  delete (VarDeclSet*)UsedVarsImpl;
+}
+
+// Returns true if the given ValueDecl is never written to in the given DeclBody
+bool PseudoConstantAnalysis::isPseudoConstant(const VarDecl *VD) {
+  // Only local and static variables can be pseudoconstants
+  if (!VD->hasLocalStorage() && !VD->isStaticLocal())
+    return false;
+
+  if (!Analyzed) {
+    RunAnalysis();
+    Analyzed = true;
+  }
+
+  VarDeclSet *NonConstants = (VarDeclSet*)NonConstantsImpl;
+
+  return !NonConstants->count(VD);
+}
+
+// Returns true if the variable was used (self assignments don't count)
+bool PseudoConstantAnalysis::wasReferenced(const VarDecl *VD) {
+  if (!Analyzed) {
+    RunAnalysis();
+    Analyzed = true;
+  }
+
+  VarDeclSet *UsedVars = (VarDeclSet*)UsedVarsImpl;
+
+  return UsedVars->count(VD);
+}
+
+// Returns a Decl from a (Block)DeclRefExpr (if any)
+const Decl *PseudoConstantAnalysis::getDecl(const Expr *E) {
+  if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E))
+    return DR->getDecl();
+  else
+    return 0;
+}
+
+void PseudoConstantAnalysis::RunAnalysis() {
+  std::deque<const Stmt *> WorkList;
+  VarDeclSet *NonConstants = (VarDeclSet*)NonConstantsImpl;
+  VarDeclSet *UsedVars = (VarDeclSet*)UsedVarsImpl;
+
+  // Start with the top level statement of the function
+  WorkList.push_back(DeclBody);
+
+  while (!WorkList.empty()) {
+    const Stmt *Head = WorkList.front();
+    WorkList.pop_front();
+
+    if (const Expr *Ex = dyn_cast<Expr>(Head))
+      Head = Ex->IgnoreParenCasts();
+
+    switch (Head->getStmtClass()) {
+    // Case 1: Assignment operators modifying VarDecls
+    case Stmt::BinaryOperatorClass: {
+      const BinaryOperator *BO = cast<BinaryOperator>(Head);
+      // Look for a Decl on the LHS
+      const Decl *LHSDecl = getDecl(BO->getLHS()->IgnoreParenCasts());
+      if (!LHSDecl)
+        break;
+
+      // We found a binary operator with a DeclRefExpr on the LHS. We now check
+      // for any of the assignment operators, implying that this Decl is being
+      // written to.
+      switch (BO->getOpcode()) {
+      // Self-assignments don't count as use of a variable
+      case BO_Assign: {
+        // Look for a DeclRef on the RHS
+        const Decl *RHSDecl = getDecl(BO->getRHS()->IgnoreParenCasts());
+
+        // If the Decls match, we have self-assignment
+        if (LHSDecl == RHSDecl)
+          // Do not visit the children
+          continue;
+
+      }
+      case BO_AddAssign:
+      case BO_SubAssign:
+      case BO_MulAssign:
+      case BO_DivAssign:
+      case BO_AndAssign:
+      case BO_OrAssign:
+      case BO_XorAssign:
+      case BO_ShlAssign:
+      case BO_ShrAssign: {
+        const VarDecl *VD = dyn_cast<VarDecl>(LHSDecl);
+        // The DeclRefExpr is being assigned to - mark it as non-constant
+        if (VD)
+          NonConstants->insert(VD);
+        break;
+      }
+
+      default:
+        break;
+      }
+      break;
+    }
+
+    // Case 2: Pre/post increment/decrement and address of
+    case Stmt::UnaryOperatorClass: {
+      const UnaryOperator *UO = cast<UnaryOperator>(Head);
+
+      // Look for a DeclRef in the subexpression
+      const Decl *D = getDecl(UO->getSubExpr()->IgnoreParenCasts());
+      if (!D)
+        break;
+
+      // We found a unary operator with a DeclRef as a subexpression. We now
+      // check for any of the increment/decrement operators, as well as
+      // addressOf.
+      switch (UO->getOpcode()) {
+      case UO_PostDec:
+      case UO_PostInc:
+      case UO_PreDec:
+      case UO_PreInc:
+        // The DeclRef is being changed - mark it as non-constant
+      case UO_AddrOf: {
+        // If we are taking the address of the DeclRefExpr, assume it is
+        // non-constant.
+        const VarDecl *VD = dyn_cast<VarDecl>(D);
+        if (VD)
+          NonConstants->insert(VD);
+        break;
+      }
+
+      default:
+        break;
+      }
+      break;
+    }
+
+    // Case 3: Reference Declarations
+    case Stmt::DeclStmtClass: {
+      const DeclStmt *DS = cast<DeclStmt>(Head);
+      // Iterate over each decl and see if any of them contain reference decls
+      for (DeclStmt::const_decl_iterator I = DS->decl_begin(),
+          E = DS->decl_end(); I != E; ++I) {
+        // We only care about VarDecls
+        const VarDecl *VD = dyn_cast<VarDecl>(*I);
+        if (!VD)
+          continue;
+
+        // We found a VarDecl; make sure it is a reference type
+        if (!VD->getType().getTypePtr()->isReferenceType())
+          continue;
+
+        // Try to find a Decl in the initializer
+        const Decl *D = getDecl(VD->getInit()->IgnoreParenCasts());
+        if (!D)
+          break;
+
+        // If the reference is to another var, add the var to the non-constant
+        // list
+        if (const VarDecl *RefVD = dyn_cast<VarDecl>(D)) {
+          NonConstants->insert(RefVD);
+          continue;
+        }
+      }
+      break;
+    }
+
+    // Case 4: Variable references
+    case Stmt::DeclRefExprClass: {
+      const DeclRefExpr *DR = cast<DeclRefExpr>(Head);
+      if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+        // Add the Decl to the used list
+        UsedVars->insert(VD);
+        continue;
+      }
+      break;
+    }
+
+    // Case 5: Block expressions
+    case Stmt::BlockExprClass: {
+      const BlockExpr *B = cast<BlockExpr>(Head);
+      // Add the body of the block to the list
+      WorkList.push_back(B->getBody());
+      continue;
+    }
+
+    default:
+      break;
+    } // switch (head->getStmtClass())
+
+    // Add all substatements to the worklist
+    for (Stmt::const_child_range I = Head->children(); I; ++I)
+      if (*I)
+        WorkList.push_back(*I);
+  } // while (!WorkList.empty())
+}
diff --git a/clang/lib/Analysis/ReachableCode.cpp b/clang/lib/Analysis/ReachableCode.cpp
new file mode 100644
index 0000000..bb63e2c
--- /dev/null
+++ b/clang/lib/Analysis/ReachableCode.cpp
@@ -0,0 +1,331 @@
+//=- ReachableCodePathInsensitive.cpp ---------------------------*- C++ --*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a flow-sensitive, path-insensitive analysis of
+// determining reachable blocks within a CFG.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallVector.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/Analysis/Analyses/ReachableCode.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Basic/SourceManager.h"
+
+using namespace clang;
+
+namespace {
+class DeadCodeScan {
+  llvm::BitVector Visited;
+  llvm::BitVector &Reachable;
+  llvm::SmallVector<const CFGBlock *, 10> WorkList;
+  
+  typedef llvm::SmallVector<std::pair<const CFGBlock *, const Stmt *>, 12>
+      DeferredLocsTy;
+  
+  DeferredLocsTy DeferredLocs;
+  
+public:
+  DeadCodeScan(llvm::BitVector &reachable)
+    : Visited(reachable.size()),
+      Reachable(reachable) {}
+  
+  void enqueue(const CFGBlock *block);  
+  unsigned scanBackwards(const CFGBlock *Start,
+                         clang::reachable_code::Callback &CB);
+  
+  bool isDeadCodeRoot(const CFGBlock *Block);
+  
+  const Stmt *findDeadCode(const CFGBlock *Block);
+  
+  void reportDeadCode(const Stmt *S,
+                      clang::reachable_code::Callback &CB);
+};
+}
+
+void DeadCodeScan::enqueue(const CFGBlock *block) {  
+  unsigned blockID = block->getBlockID();
+  if (Reachable[blockID] || Visited[blockID])
+    return;
+  Visited[blockID] = true;
+  WorkList.push_back(block);
+}
+
+bool DeadCodeScan::isDeadCodeRoot(const clang::CFGBlock *Block) {
+  bool isDeadRoot = true;
+  
+  for (CFGBlock::const_pred_iterator I = Block->pred_begin(),
+        E = Block->pred_end(); I != E; ++I) {
+    if (const CFGBlock *PredBlock = *I) {
+      unsigned blockID = PredBlock->getBlockID();
+      if (Visited[blockID]) {
+        isDeadRoot = false;
+        continue;
+      }
+      if (!Reachable[blockID]) {
+        isDeadRoot = false;
+        Visited[blockID] = true;
+        WorkList.push_back(PredBlock);
+        continue;
+      }
+    }
+  }
+  
+  return isDeadRoot;
+}
+
+static bool isValidDeadStmt(const Stmt *S) {
+  if (S->getLocStart().isInvalid())
+    return false;
+  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(S))
+    return BO->getOpcode() != BO_Comma;
+  return true;
+}
+
+const Stmt *DeadCodeScan::findDeadCode(const clang::CFGBlock *Block) {
+  for (CFGBlock::const_iterator I = Block->begin(), E = Block->end(); I!=E; ++I)
+    if (const CFGStmt *CS = I->getAs<CFGStmt>()) {
+      const Stmt *S = CS->getStmt();
+      if (isValidDeadStmt(S))
+        return S;
+    }
+  
+  if (CFGTerminator T = Block->getTerminator()) {
+    const Stmt *S = T.getStmt();
+    if (isValidDeadStmt(S))
+      return S;    
+  }
+
+  return 0;
+}
+
+static int SrcCmp(const void *p1, const void *p2) {
+  return
+    ((std::pair<const CFGBlock *, const Stmt *>*) p2)->second->getLocStart() <
+    ((std::pair<const CFGBlock *, const Stmt *>*) p1)->second->getLocStart();
+}
+
+unsigned DeadCodeScan::scanBackwards(const clang::CFGBlock *Start,
+                                     clang::reachable_code::Callback &CB) {
+
+  unsigned count = 0;
+  enqueue(Start);
+  
+  while (!WorkList.empty()) {
+    const CFGBlock *Block = WorkList.pop_back_val();
+
+    // It is possible that this block has been marked reachable after
+    // it was enqueued.
+    if (Reachable[Block->getBlockID()])
+      continue;
+
+    // Look for any dead code within the block.
+    const Stmt *S = findDeadCode(Block);
+    
+    if (!S) {
+      // No dead code.  Possibly an empty block.  Look at dead predecessors.
+      for (CFGBlock::const_pred_iterator I = Block->pred_begin(),
+           E = Block->pred_end(); I != E; ++I) {
+        if (const CFGBlock *predBlock = *I)
+          enqueue(predBlock);
+      }
+      continue;
+    }
+    
+    // Specially handle macro-expanded code.
+    if (S->getLocStart().isMacroID()) {
+      count += clang::reachable_code::ScanReachableFromBlock(Block, Reachable);
+      continue;
+    }
+
+    if (isDeadCodeRoot(Block)) {
+      reportDeadCode(S, CB);
+      count += clang::reachable_code::ScanReachableFromBlock(Block, Reachable);
+    }
+    else {
+      // Record this statement as the possibly best location in a
+      // strongly-connected component of dead code for emitting a
+      // warning.
+      DeferredLocs.push_back(std::make_pair(Block, S));
+    }
+  }
+
+  // If we didn't find a dead root, then report the dead code with the
+  // earliest location.
+  if (!DeferredLocs.empty()) {
+    llvm::array_pod_sort(DeferredLocs.begin(), DeferredLocs.end(), SrcCmp);
+    for (DeferredLocsTy::iterator I = DeferredLocs.begin(),
+          E = DeferredLocs.end(); I != E; ++I) {
+      const CFGBlock *block = I->first;
+      if (Reachable[block->getBlockID()])
+        continue;
+      reportDeadCode(I->second, CB);
+      count += clang::reachable_code::ScanReachableFromBlock(block, Reachable);
+    }
+  }
+    
+  return count;
+}
+
+static SourceLocation GetUnreachableLoc(const Stmt *S,
+                                        SourceRange &R1,
+                                        SourceRange &R2) {
+  R1 = R2 = SourceRange();
+
+  if (const Expr *Ex = dyn_cast<Expr>(S))
+    S = Ex->IgnoreParenImpCasts();
+
+  switch (S->getStmtClass()) {
+    case Expr::BinaryOperatorClass: {
+      const BinaryOperator *BO = cast<BinaryOperator>(S);
+      return BO->getOperatorLoc();
+    }
+    case Expr::UnaryOperatorClass: {
+      const UnaryOperator *UO = cast<UnaryOperator>(S);
+      R1 = UO->getSubExpr()->getSourceRange();
+      return UO->getOperatorLoc();
+    }
+    case Expr::CompoundAssignOperatorClass: {
+      const CompoundAssignOperator *CAO = cast<CompoundAssignOperator>(S);
+      R1 = CAO->getLHS()->getSourceRange();
+      R2 = CAO->getRHS()->getSourceRange();
+      return CAO->getOperatorLoc();
+    }
+    case Expr::BinaryConditionalOperatorClass:
+    case Expr::ConditionalOperatorClass: {
+      const AbstractConditionalOperator *CO =
+        cast<AbstractConditionalOperator>(S);
+      return CO->getQuestionLoc();
+    }
+    case Expr::MemberExprClass: {
+      const MemberExpr *ME = cast<MemberExpr>(S);
+      R1 = ME->getSourceRange();
+      return ME->getMemberLoc();
+    }
+    case Expr::ArraySubscriptExprClass: {
+      const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(S);
+      R1 = ASE->getLHS()->getSourceRange();
+      R2 = ASE->getRHS()->getSourceRange();
+      return ASE->getRBracketLoc();
+    }
+    case Expr::CStyleCastExprClass: {
+      const CStyleCastExpr *CSC = cast<CStyleCastExpr>(S);
+      R1 = CSC->getSubExpr()->getSourceRange();
+      return CSC->getLParenLoc();
+    }
+    case Expr::CXXFunctionalCastExprClass: {
+      const CXXFunctionalCastExpr *CE = cast <CXXFunctionalCastExpr>(S);
+      R1 = CE->getSubExpr()->getSourceRange();
+      return CE->getTypeBeginLoc();
+    }
+    case Stmt::CXXTryStmtClass: {
+      return cast<CXXTryStmt>(S)->getHandler(0)->getCatchLoc();
+    }
+    case Expr::ObjCBridgedCastExprClass: {
+      const ObjCBridgedCastExpr *CSC = cast<ObjCBridgedCastExpr>(S);
+      R1 = CSC->getSubExpr()->getSourceRange();
+      return CSC->getLParenLoc();
+    }
+    default: ;
+  }
+  R1 = S->getSourceRange();
+  return S->getLocStart();
+}
+
+void DeadCodeScan::reportDeadCode(const Stmt *S,
+                                  clang::reachable_code::Callback &CB) {
+  SourceRange R1, R2;
+  SourceLocation Loc = GetUnreachableLoc(S, R1, R2);
+  CB.HandleUnreachable(Loc, R1, R2);
+}
+
+namespace clang { namespace reachable_code {
+
+void Callback::anchor() { }  
+
+unsigned ScanReachableFromBlock(const CFGBlock *Start,
+                                llvm::BitVector &Reachable) {
+  unsigned count = 0;
+  
+  // Prep work queue
+  SmallVector<const CFGBlock*, 32> WL;
+  
+  // The entry block may have already been marked reachable
+  // by the caller.
+  if (!Reachable[Start->getBlockID()]) {
+    ++count;
+    Reachable[Start->getBlockID()] = true;
+  }
+  
+  WL.push_back(Start);
+  
+  // Find the reachable blocks from 'Start'.
+  while (!WL.empty()) {
+    const CFGBlock *item = WL.pop_back_val();
+    
+    // Look at the successors and mark then reachable.
+    for (CFGBlock::const_succ_iterator I = item->succ_begin(), 
+         E = item->succ_end(); I != E; ++I)
+      if (const CFGBlock *B = *I) {
+        unsigned blockID = B->getBlockID();
+        if (!Reachable[blockID]) {
+          Reachable.set(blockID);
+          WL.push_back(B);
+          ++count;
+        }
+      }
+  }
+  return count;
+}
+  
+void FindUnreachableCode(AnalysisDeclContext &AC, Callback &CB) {
+  CFG *cfg = AC.getCFG();
+  if (!cfg)
+    return;
+
+  // Scan for reachable blocks from the entrance of the CFG.  
+  // If there are no unreachable blocks, we're done.
+  llvm::BitVector reachable(cfg->getNumBlockIDs());
+  unsigned numReachable = ScanReachableFromBlock(&cfg->getEntry(), reachable);
+  if (numReachable == cfg->getNumBlockIDs())
+    return;
+  
+  // If there aren't explicit EH edges, we should include the 'try' dispatch
+  // blocks as roots.
+  if (!AC.getCFGBuildOptions().AddEHEdges) {
+    for (CFG::try_block_iterator I = cfg->try_blocks_begin(),
+         E = cfg->try_blocks_end() ; I != E; ++I) {
+      numReachable += ScanReachableFromBlock(*I, reachable);
+    }
+    if (numReachable == cfg->getNumBlockIDs())
+      return;
+  }
+
+  // There are some unreachable blocks.  We need to find the root blocks that
+  // contain code that should be considered unreachable.  
+  for (CFG::iterator I = cfg->begin(), E = cfg->end(); I != E; ++I) {
+    const CFGBlock *block = *I;
+    // A block may have been marked reachable during this loop.
+    if (reachable[block->getBlockID()])
+      continue;
+    
+    DeadCodeScan DS(reachable);
+    numReachable += DS.scanBackwards(block, CB);
+    
+    if (numReachable == cfg->getNumBlockIDs())
+      return;
+  }
+}
+
+}} // end namespace clang::reachable_code
diff --git a/clang/lib/Analysis/ScanfFormatString.cpp b/clang/lib/Analysis/ScanfFormatString.cpp
new file mode 100644
index 0000000..6bc4adb
--- /dev/null
+++ b/clang/lib/Analysis/ScanfFormatString.cpp
@@ -0,0 +1,499 @@
+//= ScanfFormatString.cpp - Analysis of printf format strings --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Handling of format string in scanf and friends.  The structure of format
+// strings for fscanf() are described in C99 7.19.6.2.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/FormatString.h"
+#include "FormatStringParsing.h"
+
+using clang::analyze_format_string::ArgTypeResult;
+using clang::analyze_format_string::FormatStringHandler;
+using clang::analyze_format_string::LengthModifier;
+using clang::analyze_format_string::OptionalAmount;
+using clang::analyze_format_string::ConversionSpecifier;
+using clang::analyze_scanf::ScanfArgTypeResult;
+using clang::analyze_scanf::ScanfConversionSpecifier;
+using clang::analyze_scanf::ScanfSpecifier;
+using clang::UpdateOnReturn;
+using namespace clang;
+
+typedef clang::analyze_format_string::SpecifierResult<ScanfSpecifier>
+        ScanfSpecifierResult;
+
+static bool ParseScanList(FormatStringHandler &H,
+                          ScanfConversionSpecifier &CS,
+                          const char *&Beg, const char *E) {
+  const char *I = Beg;
+  const char *start = I - 1;
+  UpdateOnReturn <const char*> UpdateBeg(Beg, I);
+
+  // No more characters?
+  if (I == E) {
+    H.HandleIncompleteScanList(start, I);
+    return true;
+  }
+  
+  // Special case: ']' is the first character.
+  if (*I == ']') {
+    if (++I == E) {
+      H.HandleIncompleteScanList(start, I - 1);
+      return true;
+    }
+  }
+
+  // Look for a ']' character which denotes the end of the scan list.
+  while (*I != ']') {
+    if (++I == E) {
+      H.HandleIncompleteScanList(start, I - 1);
+      return true;
+    }
+  }    
+
+  CS.setEndScanList(I);
+  return false;
+}
+
+// FIXME: Much of this is copy-paste from ParsePrintfSpecifier.
+// We can possibly refactor.
+static ScanfSpecifierResult ParseScanfSpecifier(FormatStringHandler &H,
+                                                const char *&Beg,
+                                                const char *E,
+                                                unsigned &argIndex,
+                                                const LangOptions &LO) {
+  
+  using namespace clang::analyze_scanf;
+  const char *I = Beg;
+  const char *Start = 0;
+  UpdateOnReturn <const char*> UpdateBeg(Beg, I);
+
+    // Look for a '%' character that indicates the start of a format specifier.
+  for ( ; I != E ; ++I) {
+    char c = *I;
+    if (c == '\0') {
+        // Detect spurious null characters, which are likely errors.
+      H.HandleNullChar(I);
+      return true;
+    }
+    if (c == '%') {
+      Start = I++;  // Record the start of the format specifier.
+      break;
+    }
+  }
+  
+    // No format specifier found?
+  if (!Start)
+    return false;
+  
+  if (I == E) {
+      // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+  
+  ScanfSpecifier FS;
+  if (ParseArgPosition(H, FS, Start, I, E))
+    return true;
+
+  if (I == E) {
+      // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+  
+  // Look for '*' flag if it is present.
+  if (*I == '*') {
+    FS.setSuppressAssignment(I);
+    if (++I == E) {
+      H.HandleIncompleteSpecifier(Start, E - Start);
+      return true;
+    }
+  }
+  
+  // Look for the field width (if any).  Unlike printf, this is either
+  // a fixed integer or isn't present.
+  const OptionalAmount &Amt = clang::analyze_format_string::ParseAmount(I, E);
+  if (Amt.getHowSpecified() != OptionalAmount::NotSpecified) {
+    assert(Amt.getHowSpecified() == OptionalAmount::Constant);
+    FS.setFieldWidth(Amt);
+
+    if (I == E) {
+      // No more characters left?
+      H.HandleIncompleteSpecifier(Start, E - Start);
+      return true;
+    }
+  }
+  
+  // Look for the length modifier.
+  if (ParseLengthModifier(FS, I, E, LO, /*scanf=*/true) && I == E) {
+      // No more characters left?
+    H.HandleIncompleteSpecifier(Start, E - Start);
+    return true;
+  }
+  
+  // Detect spurious null characters, which are likely errors.
+  if (*I == '\0') {
+    H.HandleNullChar(I);
+    return true;
+  }
+  
+  // Finally, look for the conversion specifier.
+  const char *conversionPosition = I++;
+  ScanfConversionSpecifier::Kind k = ScanfConversionSpecifier::InvalidSpecifier;
+  switch (*conversionPosition) {
+    default:
+      break;
+    case '%': k = ConversionSpecifier::PercentArg;   break;
+    case 'A': k = ConversionSpecifier::AArg; break;
+    case 'E': k = ConversionSpecifier::EArg; break;
+    case 'F': k = ConversionSpecifier::FArg; break;
+    case 'G': k = ConversionSpecifier::GArg; break;
+    case 'X': k = ConversionSpecifier::XArg; break;
+    case 'a': k = ConversionSpecifier::aArg; break;
+    case 'd': k = ConversionSpecifier::dArg; break;
+    case 'e': k = ConversionSpecifier::eArg; break;
+    case 'f': k = ConversionSpecifier::fArg; break;
+    case 'g': k = ConversionSpecifier::gArg; break;
+    case 'i': k = ConversionSpecifier::iArg; break;
+    case 'n': k = ConversionSpecifier::nArg; break;
+    case 'c': k = ConversionSpecifier::cArg; break;
+    case 'C': k = ConversionSpecifier::CArg; break;
+    case 'S': k = ConversionSpecifier::SArg; break;
+    case '[': k = ConversionSpecifier::ScanListArg; break;
+    case 'u': k = ConversionSpecifier::uArg; break;
+    case 'x': k = ConversionSpecifier::xArg; break;
+    case 'o': k = ConversionSpecifier::oArg; break;
+    case 's': k = ConversionSpecifier::sArg; break;
+    case 'p': k = ConversionSpecifier::pArg; break;
+  }
+  ScanfConversionSpecifier CS(conversionPosition, k);
+  if (k == ScanfConversionSpecifier::ScanListArg) {
+    if (ParseScanList(H, CS, I, E))
+      return true;
+  }
+  FS.setConversionSpecifier(CS);
+  if (CS.consumesDataArgument() && !FS.getSuppressAssignment()
+      && !FS.usesPositionalArg())
+    FS.setArgIndex(argIndex++);
+  
+  // FIXME: '%' and '*' doesn't make sense.  Issue a warning.
+  // FIXME: 'ConsumedSoFar' and '*' doesn't make sense.
+  
+  if (k == ScanfConversionSpecifier::InvalidSpecifier) {
+    // Assume the conversion takes one argument.
+    return !H.HandleInvalidScanfConversionSpecifier(FS, Beg, I - Beg);
+  }
+  return ScanfSpecifierResult(Start, FS);
+}
+
+ScanfArgTypeResult ScanfSpecifier::getArgType(ASTContext &Ctx) const {
+  const ScanfConversionSpecifier &CS = getConversionSpecifier();
+
+  if (!CS.consumesDataArgument())
+    return ScanfArgTypeResult::Invalid();
+
+  switch(CS.getKind()) {
+    // Signed int.
+    case ConversionSpecifier::dArg:
+    case ConversionSpecifier::iArg:
+      switch (LM.getKind()) {
+        case LengthModifier::None: return ArgTypeResult(Ctx.IntTy);
+        case LengthModifier::AsChar:
+          return ArgTypeResult(ArgTypeResult::AnyCharTy);
+        case LengthModifier::AsShort: return ArgTypeResult(Ctx.ShortTy);
+        case LengthModifier::AsLong: return ArgTypeResult(Ctx.LongTy);
+        case LengthModifier::AsLongLong:
+        case LengthModifier::AsQuad:
+          return ArgTypeResult(Ctx.LongLongTy);
+        case LengthModifier::AsIntMax:
+          return ScanfArgTypeResult(Ctx.getIntMaxType(), "intmax_t *");
+        case LengthModifier::AsSizeT:
+          // FIXME: ssize_t.
+          return ScanfArgTypeResult();
+        case LengthModifier::AsPtrDiff:
+          return ScanfArgTypeResult(Ctx.getPointerDiffType(), "ptrdiff_t *");
+        case LengthModifier::AsLongDouble:
+          // GNU extension.
+          return ArgTypeResult(Ctx.LongLongTy);
+        case LengthModifier::AsAllocate: return ScanfArgTypeResult::Invalid();
+        case LengthModifier::AsMAllocate: return ScanfArgTypeResult::Invalid();
+      }
+
+    // Unsigned int.
+    case ConversionSpecifier::oArg:
+    case ConversionSpecifier::uArg:
+    case ConversionSpecifier::xArg:
+    case ConversionSpecifier::XArg:
+      switch (LM.getKind()) {
+        case LengthModifier::None: return ArgTypeResult(Ctx.UnsignedIntTy);
+        case LengthModifier::AsChar: return ArgTypeResult(Ctx.UnsignedCharTy);
+        case LengthModifier::AsShort: return ArgTypeResult(Ctx.UnsignedShortTy);
+        case LengthModifier::AsLong: return ArgTypeResult(Ctx.UnsignedLongTy);
+        case LengthModifier::AsLongLong:
+        case LengthModifier::AsQuad:
+          return ArgTypeResult(Ctx.UnsignedLongLongTy);
+        case LengthModifier::AsIntMax:
+          return ScanfArgTypeResult(Ctx.getUIntMaxType(), "uintmax_t *");
+        case LengthModifier::AsSizeT:
+          return ScanfArgTypeResult(Ctx.getSizeType(), "size_t *");
+        case LengthModifier::AsPtrDiff:
+          // FIXME: Unsigned version of ptrdiff_t?
+          return ScanfArgTypeResult();
+        case LengthModifier::AsLongDouble:
+          // GNU extension.
+          return ArgTypeResult(Ctx.UnsignedLongLongTy);
+        case LengthModifier::AsAllocate: return ScanfArgTypeResult::Invalid();
+        case LengthModifier::AsMAllocate: return ScanfArgTypeResult::Invalid();
+      }
+
+    // Float.
+    case ConversionSpecifier::aArg:
+    case ConversionSpecifier::AArg:
+    case ConversionSpecifier::eArg:
+    case ConversionSpecifier::EArg:
+    case ConversionSpecifier::fArg:
+    case ConversionSpecifier::FArg:
+    case ConversionSpecifier::gArg:
+    case ConversionSpecifier::GArg:
+      switch (LM.getKind()) {
+        case LengthModifier::None: return ArgTypeResult(Ctx.FloatTy);
+        case LengthModifier::AsLong: return ArgTypeResult(Ctx.DoubleTy);
+        case LengthModifier::AsLongDouble:
+          return ArgTypeResult(Ctx.LongDoubleTy);
+        default:
+          return ScanfArgTypeResult::Invalid();
+      }
+
+    // Char, string and scanlist.
+    case ConversionSpecifier::cArg:
+    case ConversionSpecifier::sArg:
+    case ConversionSpecifier::ScanListArg:
+      switch (LM.getKind()) {
+        case LengthModifier::None: return ScanfArgTypeResult::CStrTy;
+        case LengthModifier::AsLong:
+          return ScanfArgTypeResult(ScanfArgTypeResult::WCStrTy, "wchar_t *");
+        case LengthModifier::AsAllocate:
+        case LengthModifier::AsMAllocate:
+          return ScanfArgTypeResult(ArgTypeResult::CStrTy);
+        default:
+          return ScanfArgTypeResult::Invalid();
+      }
+    case ConversionSpecifier::CArg:
+    case ConversionSpecifier::SArg:
+      // FIXME: Mac OS X specific?
+      switch (LM.getKind()) {
+        case LengthModifier::None:
+          return ScanfArgTypeResult(ScanfArgTypeResult::WCStrTy, "wchar_t *");
+        case LengthModifier::AsAllocate:
+        case LengthModifier::AsMAllocate:
+          return ScanfArgTypeResult(ArgTypeResult::WCStrTy, "wchar_t **");
+        default:
+          return ScanfArgTypeResult::Invalid();
+      }
+
+    // Pointer.
+    case ConversionSpecifier::pArg:
+      return ScanfArgTypeResult(ArgTypeResult(ArgTypeResult::CPointerTy));
+
+    default:
+      break;
+  }
+
+  return ScanfArgTypeResult();
+}
+
+bool ScanfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
+                             ASTContext &Ctx) {
+  if (!QT->isPointerType())
+    return false;
+
+  QualType PT = QT->getPointeeType();
+  const BuiltinType *BT = PT->getAs<BuiltinType>();
+  if (!BT)
+    return false;
+
+  // Pointer to a character.
+  if (PT->isAnyCharacterType()) {
+    CS.setKind(ConversionSpecifier::sArg);
+    if (PT->isWideCharType())
+      LM.setKind(LengthModifier::AsWideChar);
+    else
+      LM.setKind(LengthModifier::None);
+    return true;
+  }
+
+  // Figure out the length modifier.
+  switch (BT->getKind()) {
+    // no modifier
+    case BuiltinType::UInt:
+    case BuiltinType::Int:
+    case BuiltinType::Float:
+      LM.setKind(LengthModifier::None);
+      break;
+
+    // hh
+    case BuiltinType::Char_U:
+    case BuiltinType::UChar:
+    case BuiltinType::Char_S:
+    case BuiltinType::SChar:
+      LM.setKind(LengthModifier::AsChar);
+      break;
+
+    // h
+    case BuiltinType::Short:
+    case BuiltinType::UShort:
+      LM.setKind(LengthModifier::AsShort);
+      break;
+
+    // l
+    case BuiltinType::Long:
+    case BuiltinType::ULong:
+    case BuiltinType::Double:
+      LM.setKind(LengthModifier::AsLong);
+      break;
+
+    // ll
+    case BuiltinType::LongLong:
+    case BuiltinType::ULongLong:
+      LM.setKind(LengthModifier::AsLongLong);
+      break;
+
+    // L
+    case BuiltinType::LongDouble:
+      LM.setKind(LengthModifier::AsLongDouble);
+      break;
+
+    // Don't know.
+    default:
+      return false;
+  }
+
+  // Handle size_t, ptrdiff_t, etc. that have dedicated length modifiers in C99.
+  if (isa<TypedefType>(PT) && (LangOpt.C99 || LangOpt.CPlusPlus0x)) {
+    const IdentifierInfo *Identifier = QT.getBaseTypeIdentifier();
+    if (Identifier->getName() == "size_t") {
+      LM.setKind(LengthModifier::AsSizeT);
+    } else if (Identifier->getName() == "ssize_t") {
+      // Not C99, but common in Unix.
+      LM.setKind(LengthModifier::AsSizeT);
+    } else if (Identifier->getName() == "intmax_t") {
+      LM.setKind(LengthModifier::AsIntMax);
+    } else if (Identifier->getName() == "uintmax_t") {
+      LM.setKind(LengthModifier::AsIntMax);
+    } else if (Identifier->getName() == "ptrdiff_t") {
+      LM.setKind(LengthModifier::AsPtrDiff);
+    }
+  }
+
+  // If fixing the length modifier was enough, we are done.
+  const analyze_scanf::ScanfArgTypeResult &ATR = getArgType(Ctx);
+  if (hasValidLengthModifier() && ATR.isValid() && ATR.matchesType(Ctx, QT))
+    return true;
+
+  // Figure out the conversion specifier.
+  if (PT->isRealFloatingType())
+    CS.setKind(ConversionSpecifier::fArg);
+  else if (PT->isSignedIntegerType())
+    CS.setKind(ConversionSpecifier::dArg);
+  else if (PT->isUnsignedIntegerType())
+    CS.setKind(ConversionSpecifier::uArg);
+  else
+    llvm_unreachable("Unexpected type");
+
+  return true;
+}
+
+void ScanfSpecifier::toString(raw_ostream &os) const {
+  os << "%";
+
+  if (usesPositionalArg())
+    os << getPositionalArgIndex() << "$";
+  if (SuppressAssignment)
+    os << "*";
+
+  FieldWidth.toString(os);
+  os << LM.toString();
+  os << CS.toString();
+}
+
+bool clang::analyze_format_string::ParseScanfString(FormatStringHandler &H,
+                                                    const char *I,
+                                                    const char *E,
+                                                    const LangOptions &LO) {
+  
+  unsigned argIndex = 0;
+  
+  // Keep looking for a format specifier until we have exhausted the string.
+  while (I != E) {
+    const ScanfSpecifierResult &FSR = ParseScanfSpecifier(H, I, E, argIndex,
+                                                          LO);
+    // Did a fail-stop error of any kind occur when parsing the specifier?
+    // If so, don't do any more processing.
+    if (FSR.shouldStop())
+      return true;;
+      // Did we exhaust the string or encounter an error that
+      // we can recover from?
+    if (!FSR.hasValue())
+      continue;
+      // We have a format specifier.  Pass it to the callback.
+    if (!H.HandleScanfSpecifier(FSR.getValue(), FSR.getStart(),
+                                I - FSR.getStart())) {
+      return true;
+    }
+  }
+  assert(I == E && "Format string not exhausted");
+  return false;
+}
+
+bool ScanfArgTypeResult::matchesType(ASTContext& C, QualType argTy) const {
+  switch (K) {
+    case InvalidTy:
+      llvm_unreachable("ArgTypeResult must be valid");
+    case UnknownTy:
+      return true;
+    case CStrTy:
+      return ArgTypeResult(ArgTypeResult::CStrTy).matchesType(C, argTy);
+    case WCStrTy:
+      return ArgTypeResult(ArgTypeResult::WCStrTy).matchesType(C, argTy);
+    case PtrToArgTypeResultTy: {
+      const PointerType *PT = argTy->getAs<PointerType>();
+      if (!PT)
+        return false;
+      return A.matchesType(C, PT->getPointeeType());
+    }
+  }
+
+  llvm_unreachable("Invalid ScanfArgTypeResult Kind!");
+}
+
+QualType ScanfArgTypeResult::getRepresentativeType(ASTContext &C) const {
+  switch (K) {
+    case InvalidTy:
+      llvm_unreachable("No representative type for Invalid ArgTypeResult");
+    case UnknownTy:
+      return QualType();
+    case CStrTy:
+      return C.getPointerType(C.CharTy);
+    case WCStrTy:
+      return C.getPointerType(C.getWCharType());
+    case PtrToArgTypeResultTy:
+      return C.getPointerType(A.getRepresentativeType(C));
+  }
+
+  llvm_unreachable("Invalid ScanfArgTypeResult Kind!");
+}
+
+std::string ScanfArgTypeResult::getRepresentativeTypeName(ASTContext& C) const {
+  std::string S = getRepresentativeType(C).getAsString();
+  if (!Name)
+    return std::string("'") + S + "'";
+  return std::string("'") + Name + "' (aka '" + S + "')";
+}
diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
new file mode 100644
index 0000000..2f7e794
--- /dev/null
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -0,0 +1,1726 @@
+//===- ThreadSafety.cpp ----------------------------------------*- C++ --*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// A intra-procedural analysis for thread safety (e.g. deadlocks and race
+// conditions), based off of an annotation system.
+//
+// See http://clang.llvm.org/docs/LanguageExtensions.html#threadsafety for more
+// information.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/ThreadSafety.h"
+#include "clang/Analysis/Analyses/PostOrderCFGView.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/CFGStmtMap.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/ImmutableMap.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <utility>
+#include <vector>
+
+using namespace clang;
+using namespace thread_safety;
+
+// Key method definition
+ThreadSafetyHandler::~ThreadSafetyHandler() {}
+
+namespace {
+
+/// \brief A MutexID object uniquely identifies a particular mutex, and
+/// is built from an Expr* (i.e. calling a lock function).
+///
+/// Thread-safety analysis works by comparing lock expressions.  Within the
+/// body of a function, an expression such as "x->foo->bar.mu" will resolve to
+/// a particular mutex object at run-time.  Subsequent occurrences of the same
+/// expression (where "same" means syntactic equality) will refer to the same
+/// run-time object if three conditions hold:
+/// (1) Local variables in the expression, such as "x" have not changed.
+/// (2) Values on the heap that affect the expression have not changed.
+/// (3) The expression involves only pure function calls.
+///
+/// The current implementation assumes, but does not verify, that multiple uses
+/// of the same lock expression satisfies these criteria.
+///
+/// Clang introduces an additional wrinkle, which is that it is difficult to
+/// derive canonical expressions, or compare expressions directly for equality.
+/// Thus, we identify a mutex not by an Expr, but by the list of named
+/// declarations that are referenced by the Expr.  In other words,
+/// x->foo->bar.mu will be a four element vector with the Decls for
+/// mu, bar, and foo, and x.  The vector will uniquely identify the expression
+/// for all practical purposes.  Null is used to denote 'this'.
+///
+/// Note we will need to perform substitution on "this" and function parameter
+/// names when constructing a lock expression.
+///
+/// For example:
+/// class C { Mutex Mu;  void lock() EXCLUSIVE_LOCK_FUNCTION(this->Mu); };
+/// void myFunc(C *X) { ... X->lock() ... }
+/// The original expression for the mutex acquired by myFunc is "this->Mu", but
+/// "X" is substituted for "this" so we get X->Mu();
+///
+/// For another example:
+/// foo(MyList *L) EXCLUSIVE_LOCKS_REQUIRED(L->Mu) { ... }
+/// MyList *MyL;
+/// foo(MyL);  // requires lock MyL->Mu to be held
+class MutexID {
+  SmallVector<NamedDecl*, 2> DeclSeq;
+
+  /// Build a Decl sequence representing the lock from the given expression.
+  /// Recursive function that terminates on DeclRefExpr.
+  /// Note: this function merely creates a MutexID; it does not check to
+  /// ensure that the original expression is a valid mutex expression.
+  void buildMutexID(Expr *Exp, const NamedDecl *D, Expr *Parent,
+                    unsigned NumArgs, Expr **FunArgs) {
+    if (!Exp) {
+      DeclSeq.clear();
+      return;
+    }
+
+    if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Exp)) {
+      NamedDecl *ND = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
+      ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(ND);
+      if (PV) {
+        FunctionDecl *FD =
+          cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
+        unsigned i = PV->getFunctionScopeIndex();
+
+        if (FunArgs && FD == D->getCanonicalDecl()) {
+          // Substitute call arguments for references to function parameters
+          assert(i < NumArgs);
+          buildMutexID(FunArgs[i], D, 0, 0, 0);
+          return;
+        }
+        // Map the param back to the param of the original function declaration.
+        DeclSeq.push_back(FD->getParamDecl(i));
+        return;
+      }
+      // Not a function parameter -- just store the reference.
+      DeclSeq.push_back(ND);
+    } else if (MemberExpr *ME = dyn_cast<MemberExpr>(Exp)) {
+      NamedDecl *ND = ME->getMemberDecl();
+      DeclSeq.push_back(ND);
+      buildMutexID(ME->getBase(), D, Parent, NumArgs, FunArgs);
+    } else if (isa<CXXThisExpr>(Exp)) {
+      if (Parent)
+        buildMutexID(Parent, D, 0, 0, 0);
+      else {
+        DeclSeq.push_back(0);  // Use 0 to represent 'this'.
+        return;  // mutexID is still valid in this case
+      }
+    } else if (CXXMemberCallExpr *CMCE = dyn_cast<CXXMemberCallExpr>(Exp)) {
+      DeclSeq.push_back(CMCE->getMethodDecl()->getCanonicalDecl());
+      buildMutexID(CMCE->getImplicitObjectArgument(),
+                   D, Parent, NumArgs, FunArgs);
+      unsigned NumCallArgs = CMCE->getNumArgs();
+      Expr** CallArgs = CMCE->getArgs();
+      for (unsigned i = 0; i < NumCallArgs; ++i) {
+        buildMutexID(CallArgs[i], D, Parent, NumArgs, FunArgs);
+      }
+    } else if (CallExpr *CE = dyn_cast<CallExpr>(Exp)) {
+      buildMutexID(CE->getCallee(), D, Parent, NumArgs, FunArgs);
+      unsigned NumCallArgs = CE->getNumArgs();
+      Expr** CallArgs = CE->getArgs();
+      for (unsigned i = 0; i < NumCallArgs; ++i) {
+        buildMutexID(CallArgs[i], D, Parent, NumArgs, FunArgs);
+      }
+    } else if (BinaryOperator *BOE = dyn_cast<BinaryOperator>(Exp)) {
+      buildMutexID(BOE->getLHS(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(BOE->getRHS(), D, Parent, NumArgs, FunArgs);
+    } else if (UnaryOperator *UOE = dyn_cast<UnaryOperator>(Exp)) {
+      buildMutexID(UOE->getSubExpr(), D, Parent, NumArgs, FunArgs);
+    } else if (ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(Exp)) {
+      buildMutexID(ASE->getBase(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(ASE->getIdx(), D, Parent, NumArgs, FunArgs);
+    } else if (AbstractConditionalOperator *CE =
+                 dyn_cast<AbstractConditionalOperator>(Exp)) {
+      buildMutexID(CE->getCond(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(CE->getTrueExpr(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(CE->getFalseExpr(), D, Parent, NumArgs, FunArgs);
+    } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(Exp)) {
+      buildMutexID(CE->getCond(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(CE->getLHS(), D, Parent, NumArgs, FunArgs);
+      buildMutexID(CE->getRHS(), D, Parent, NumArgs, FunArgs);
+    } else if (CastExpr *CE = dyn_cast<CastExpr>(Exp)) {
+      buildMutexID(CE->getSubExpr(), D, Parent, NumArgs, FunArgs);
+    } else if (ParenExpr *PE = dyn_cast<ParenExpr>(Exp)) {
+      buildMutexID(PE->getSubExpr(), D, Parent, NumArgs, FunArgs);
+    } else if (isa<CharacterLiteral>(Exp) ||
+             isa<CXXNullPtrLiteralExpr>(Exp) ||
+             isa<GNUNullExpr>(Exp) ||
+             isa<CXXBoolLiteralExpr>(Exp) ||
+             isa<FloatingLiteral>(Exp) ||
+             isa<ImaginaryLiteral>(Exp) ||
+             isa<IntegerLiteral>(Exp) ||
+             isa<StringLiteral>(Exp) ||
+             isa<ObjCStringLiteral>(Exp)) {
+      return;  // FIXME: Ignore literals for now
+    } else {
+      // Ignore.  FIXME: mark as invalid expression?
+    }
+  }
+
+  /// \brief Construct a MutexID from an expression.
+  /// \param MutexExp The original mutex expression within an attribute
+  /// \param DeclExp An expression involving the Decl on which the attribute
+  ///        occurs.
+  /// \param D  The declaration to which the lock/unlock attribute is attached.
+  void buildMutexIDFromExp(Expr *MutexExp, Expr *DeclExp, const NamedDecl *D) {
+    Expr *Parent = 0;
+    unsigned NumArgs = 0;
+    Expr **FunArgs = 0;
+
+    // If we are processing a raw attribute expression, with no substitutions.
+    if (DeclExp == 0) {
+      buildMutexID(MutexExp, D, 0, 0, 0);
+      return;
+    }
+
+    // Examine DeclExp to find Parent and FunArgs, which are used to substitute
+    // for formal parameters when we call buildMutexID later.
+    if (MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
+      Parent = ME->getBase();
+    } else if (CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(DeclExp)) {
+      Parent = CE->getImplicitObjectArgument();
+      NumArgs = CE->getNumArgs();
+      FunArgs = CE->getArgs();
+    } else if (CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) {
+      NumArgs = CE->getNumArgs();
+      FunArgs = CE->getArgs();
+    } else if (CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(DeclExp)) {
+      Parent = 0;  // FIXME -- get the parent from DeclStmt
+      NumArgs = CE->getNumArgs();
+      FunArgs = CE->getArgs();
+    } else if (D && isa<CXXDestructorDecl>(D)) {
+      // There's no such thing as a "destructor call" in the AST.
+      Parent = DeclExp;
+    }
+
+    // If the attribute has no arguments, then assume the argument is "this".
+    if (MutexExp == 0) {
+      buildMutexID(Parent, D, 0, 0, 0);
+      return;
+    }
+
+    buildMutexID(MutexExp, D, Parent, NumArgs, FunArgs);
+  }
+
+public:
+  explicit MutexID(clang::Decl::EmptyShell e) {
+    DeclSeq.clear();
+  }
+
+  /// \param MutexExp The original mutex expression within an attribute
+  /// \param DeclExp An expression involving the Decl on which the attribute
+  ///        occurs.
+  /// \param D  The declaration to which the lock/unlock attribute is attached.
+  /// Caller must check isValid() after construction.
+  MutexID(Expr* MutexExp, Expr *DeclExp, const NamedDecl* D) {
+    buildMutexIDFromExp(MutexExp, DeclExp, D);
+  }
+
+  /// Return true if this is a valid decl sequence.
+  /// Caller must call this by hand after construction to handle errors.
+  bool isValid() const {
+    return !DeclSeq.empty();
+  }
+
+  /// Issue a warning about an invalid lock expression
+  static void warnInvalidLock(ThreadSafetyHandler &Handler, Expr* MutexExp,
+                              Expr *DeclExp, const NamedDecl* D) {
+    SourceLocation Loc;
+    if (DeclExp)
+      Loc = DeclExp->getExprLoc();
+
+    // FIXME: add a note about the attribute location in MutexExp or D
+    if (Loc.isValid())
+      Handler.handleInvalidLockExp(Loc);
+  }
+
+  bool operator==(const MutexID &other) const {
+    return DeclSeq == other.DeclSeq;
+  }
+
+  bool operator!=(const MutexID &other) const {
+    return !(*this == other);
+  }
+
+  // SmallVector overloads Operator< to do lexicographic ordering. Note that
+  // we use pointer equality (and <) to compare NamedDecls. This means the order
+  // of MutexIDs in a lockset is nondeterministic. In order to output
+  // diagnostics in a deterministic ordering, we must order all diagnostics to
+  // output by SourceLocation when iterating through this lockset.
+  bool operator<(const MutexID &other) const {
+    return DeclSeq < other.DeclSeq;
+  }
+
+  /// \brief Returns the name of the first Decl in the list for a given MutexID;
+  /// e.g. the lock expression foo.bar() has name "bar".
+  /// The caret will point unambiguously to the lock expression, so using this
+  /// name in diagnostics is a way to get simple, and consistent, mutex names.
+  /// We do not want to output the entire expression text for security reasons.
+  std::string getName() const {
+    assert(isValid());
+    if (!DeclSeq.front())
+      return "this";  // Use 0 to represent 'this'.
+    return DeclSeq.front()->getNameAsString();
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    for (SmallVectorImpl<NamedDecl*>::const_iterator I = DeclSeq.begin(),
+         E = DeclSeq.end(); I != E; ++I) {
+      ID.AddPointer(*I);
+    }
+  }
+};
+
+
+/// \brief This is a helper class that stores info about the most recent
+/// accquire of a Lock.
+///
+/// The main body of the analysis maps MutexIDs to LockDatas.
+struct LockData {
+  SourceLocation AcquireLoc;
+
+  /// \brief LKind stores whether a lock is held shared or exclusively.
+  /// Note that this analysis does not currently support either re-entrant
+  /// locking or lock "upgrading" and "downgrading" between exclusive and
+  /// shared.
+  ///
+  /// FIXME: add support for re-entrant locking and lock up/downgrading
+  LockKind LKind;
+  MutexID UnderlyingMutex;  // for ScopedLockable objects
+
+  LockData(SourceLocation AcquireLoc, LockKind LKind)
+    : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Decl::EmptyShell())
+  {}
+
+  LockData(SourceLocation AcquireLoc, LockKind LKind, const MutexID &Mu)
+    : AcquireLoc(AcquireLoc), LKind(LKind), UnderlyingMutex(Mu) {}
+
+  bool operator==(const LockData &other) const {
+    return AcquireLoc == other.AcquireLoc && LKind == other.LKind;
+  }
+
+  bool operator!=(const LockData &other) const {
+    return !(*this == other);
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    ID.AddInteger(AcquireLoc.getRawEncoding());
+    ID.AddInteger(LKind);
+  }
+};
+
+
+/// A Lockset maps each MutexID (defined above) to information about how it has
+/// been locked.
+typedef llvm::ImmutableMap<MutexID, LockData> Lockset;
+typedef llvm::ImmutableMap<NamedDecl*, unsigned> LocalVarContext;
+
+class LocalVariableMap;
+
+/// A side (entry or exit) of a CFG node.
+enum CFGBlockSide { CBS_Entry, CBS_Exit };
+
+/// CFGBlockInfo is a struct which contains all the information that is
+/// maintained for each block in the CFG.  See LocalVariableMap for more
+/// information about the contexts.
+struct CFGBlockInfo {
+  Lockset EntrySet;             // Lockset held at entry to block
+  Lockset ExitSet;              // Lockset held at exit from block
+  LocalVarContext EntryContext; // Context held at entry to block
+  LocalVarContext ExitContext;  // Context held at exit from block
+  SourceLocation EntryLoc;      // Location of first statement in block
+  SourceLocation ExitLoc;       // Location of last statement in block.
+  unsigned EntryIndex;          // Used to replay contexts later
+
+  const Lockset &getSet(CFGBlockSide Side) const {
+    return Side == CBS_Entry ? EntrySet : ExitSet;
+  }
+  SourceLocation getLocation(CFGBlockSide Side) const {
+    return Side == CBS_Entry ? EntryLoc : ExitLoc;
+  }
+
+private:
+  CFGBlockInfo(Lockset EmptySet, LocalVarContext EmptyCtx)
+    : EntrySet(EmptySet), ExitSet(EmptySet),
+      EntryContext(EmptyCtx), ExitContext(EmptyCtx)
+  { }
+
+public:
+  static CFGBlockInfo getEmptyBlockInfo(Lockset::Factory &F,
+                                        LocalVariableMap &M);
+};
+
+
+
+// A LocalVariableMap maintains a map from local variables to their currently
+// valid definitions.  It provides SSA-like functionality when traversing the
+// CFG.  Like SSA, each definition or assignment to a variable is assigned a
+// unique name (an integer), which acts as the SSA name for that definition.
+// The total set of names is shared among all CFG basic blocks.
+// Unlike SSA, we do not rewrite expressions to replace local variables declrefs
+// with their SSA-names.  Instead, we compute a Context for each point in the
+// code, which maps local variables to the appropriate SSA-name.  This map
+// changes with each assignment.
+//
+// The map is computed in a single pass over the CFG.  Subsequent analyses can
+// then query the map to find the appropriate Context for a statement, and use
+// that Context to look up the definitions of variables.
+class LocalVariableMap {
+public:
+  typedef LocalVarContext Context;
+
+  /// A VarDefinition consists of an expression, representing the value of the
+  /// variable, along with the context in which that expression should be
+  /// interpreted.  A reference VarDefinition does not itself contain this
+  /// information, but instead contains a pointer to a previous VarDefinition.
+  struct VarDefinition {
+  public:
+    friend class LocalVariableMap;
+
+    NamedDecl *Dec;       // The original declaration for this variable.
+    Expr *Exp;            // The expression for this variable, OR
+    unsigned Ref;         // Reference to another VarDefinition
+    Context Ctx;          // The map with which Exp should be interpreted.
+
+    bool isReference() { return !Exp; }
+
+  private:
+    // Create ordinary variable definition
+    VarDefinition(NamedDecl *D, Expr *E, Context C)
+      : Dec(D), Exp(E), Ref(0), Ctx(C)
+    { }
+
+    // Create reference to previous definition
+    VarDefinition(NamedDecl *D, unsigned R, Context C)
+      : Dec(D), Exp(0), Ref(R), Ctx(C)
+    { }
+  };
+
+private:
+  Context::Factory ContextFactory;
+  std::vector<VarDefinition> VarDefinitions;
+  std::vector<unsigned> CtxIndices;
+  std::vector<std::pair<Stmt*, Context> > SavedContexts;
+
+public:
+  LocalVariableMap() {
+    // index 0 is a placeholder for undefined variables (aka phi-nodes).
+    VarDefinitions.push_back(VarDefinition(0, 0u, getEmptyContext()));
+  }
+
+  /// Look up a definition, within the given context.
+  const VarDefinition* lookup(NamedDecl *D, Context Ctx) {
+    const unsigned *i = Ctx.lookup(D);
+    if (!i)
+      return 0;
+    assert(*i < VarDefinitions.size());
+    return &VarDefinitions[*i];
+  }
+
+  /// Look up the definition for D within the given context.  Returns
+  /// NULL if the expression is not statically known.  If successful, also
+  /// modifies Ctx to hold the context of the return Expr.
+  Expr* lookupExpr(NamedDecl *D, Context &Ctx) {
+    const unsigned *P = Ctx.lookup(D);
+    if (!P)
+      return 0;
+
+    unsigned i = *P;
+    while (i > 0) {
+      if (VarDefinitions[i].Exp) {
+        Ctx = VarDefinitions[i].Ctx;
+        return VarDefinitions[i].Exp;
+      }
+      i = VarDefinitions[i].Ref;
+    }
+    return 0;
+  }
+
+  Context getEmptyContext() { return ContextFactory.getEmptyMap(); }
+
+  /// Return the next context after processing S.  This function is used by
+  /// clients of the class to get the appropriate context when traversing the
+  /// CFG.  It must be called for every assignment or DeclStmt.
+  Context getNextContext(unsigned &CtxIndex, Stmt *S, Context C) {
+    if (SavedContexts[CtxIndex+1].first == S) {
+      CtxIndex++;
+      Context Result = SavedContexts[CtxIndex].second;
+      return Result;
+    }
+    return C;
+  }
+
+  void dumpVarDefinitionName(unsigned i) {
+    if (i == 0) {
+      llvm::errs() << "Undefined";
+      return;
+    }
+    NamedDecl *Dec = VarDefinitions[i].Dec;
+    if (!Dec) {
+      llvm::errs() << "<<NULL>>";
+      return;
+    }
+    Dec->printName(llvm::errs());
+    llvm::errs() << "." << i << " " << ((void*) Dec);
+  }
+
+  /// Dumps an ASCII representation of the variable map to llvm::errs()
+  void dump() {
+    for (unsigned i = 1, e = VarDefinitions.size(); i < e; ++i) {
+      Expr *Exp = VarDefinitions[i].Exp;
+      unsigned Ref = VarDefinitions[i].Ref;
+
+      dumpVarDefinitionName(i);
+      llvm::errs() << " = ";
+      if (Exp) Exp->dump();
+      else {
+        dumpVarDefinitionName(Ref);
+        llvm::errs() << "\n";
+      }
+    }
+  }
+
+  /// Dumps an ASCII representation of a Context to llvm::errs()
+  void dumpContext(Context C) {
+    for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) {
+      NamedDecl *D = I.getKey();
+      D->printName(llvm::errs());
+      const unsigned *i = C.lookup(D);
+      llvm::errs() << " -> ";
+      dumpVarDefinitionName(*i);
+      llvm::errs() << "\n";
+    }
+  }
+
+  /// Builds the variable map.
+  void traverseCFG(CFG *CFGraph, PostOrderCFGView *SortedGraph,
+                     std::vector<CFGBlockInfo> &BlockInfo);
+
+protected:
+  // Get the current context index
+  unsigned getContextIndex() { return SavedContexts.size()-1; }
+
+  // Save the current context for later replay
+  void saveContext(Stmt *S, Context C) {
+    SavedContexts.push_back(std::make_pair(S,C));
+  }
+
+  // Adds a new definition to the given context, and returns a new context.
+  // This method should be called when declaring a new variable.
+  Context addDefinition(NamedDecl *D, Expr *Exp, Context Ctx) {
+    assert(!Ctx.contains(D));
+    unsigned newID = VarDefinitions.size();
+    Context NewCtx = ContextFactory.add(Ctx, D, newID);
+    VarDefinitions.push_back(VarDefinition(D, Exp, Ctx));
+    return NewCtx;
+  }
+
+  // Add a new reference to an existing definition.
+  Context addReference(NamedDecl *D, unsigned i, Context Ctx) {
+    unsigned newID = VarDefinitions.size();
+    Context NewCtx = ContextFactory.add(Ctx, D, newID);
+    VarDefinitions.push_back(VarDefinition(D, i, Ctx));
+    return NewCtx;
+  }
+
+  // Updates a definition only if that definition is already in the map.
+  // This method should be called when assigning to an existing variable.
+  Context updateDefinition(NamedDecl *D, Expr *Exp, Context Ctx) {
+    if (Ctx.contains(D)) {
+      unsigned newID = VarDefinitions.size();
+      Context NewCtx = ContextFactory.remove(Ctx, D);
+      NewCtx = ContextFactory.add(NewCtx, D, newID);
+      VarDefinitions.push_back(VarDefinition(D, Exp, Ctx));
+      return NewCtx;
+    }
+    return Ctx;
+  }
+
+  // Removes a definition from the context, but keeps the variable name
+  // as a valid variable.  The index 0 is a placeholder for cleared definitions.
+  Context clearDefinition(NamedDecl *D, Context Ctx) {
+    Context NewCtx = Ctx;
+    if (NewCtx.contains(D)) {
+      NewCtx = ContextFactory.remove(NewCtx, D);
+      NewCtx = ContextFactory.add(NewCtx, D, 0);
+    }
+    return NewCtx;
+  }
+
+  // Remove a definition entirely frmo the context.
+  Context removeDefinition(NamedDecl *D, Context Ctx) {
+    Context NewCtx = Ctx;
+    if (NewCtx.contains(D)) {
+      NewCtx = ContextFactory.remove(NewCtx, D);
+    }
+    return NewCtx;
+  }
+
+  Context intersectContexts(Context C1, Context C2);
+  Context createReferenceContext(Context C);
+  void intersectBackEdge(Context C1, Context C2);
+
+  friend class VarMapBuilder;
+};
+
+
+// This has to be defined after LocalVariableMap.
+CFGBlockInfo CFGBlockInfo::getEmptyBlockInfo(Lockset::Factory &F,
+                                             LocalVariableMap &M) {
+  return CFGBlockInfo(F.getEmptyMap(), M.getEmptyContext());
+}
+
+
+/// Visitor which builds a LocalVariableMap
+class VarMapBuilder : public StmtVisitor<VarMapBuilder> {
+public:
+  LocalVariableMap* VMap;
+  LocalVariableMap::Context Ctx;
+
+  VarMapBuilder(LocalVariableMap *VM, LocalVariableMap::Context C)
+    : VMap(VM), Ctx(C) {}
+
+  void VisitDeclStmt(DeclStmt *S);
+  void VisitBinaryOperator(BinaryOperator *BO);
+};
+
+
+// Add new local variables to the variable map
+void VarMapBuilder::VisitDeclStmt(DeclStmt *S) {
+  bool modifiedCtx = false;
+  DeclGroupRef DGrp = S->getDeclGroup();
+  for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) {
+    if (VarDecl *VD = dyn_cast_or_null<VarDecl>(*I)) {
+      Expr *E = VD->getInit();
+
+      // Add local variables with trivial type to the variable map
+      QualType T = VD->getType();
+      if (T.isTrivialType(VD->getASTContext())) {
+        Ctx = VMap->addDefinition(VD, E, Ctx);
+        modifiedCtx = true;
+      }
+    }
+  }
+  if (modifiedCtx)
+    VMap->saveContext(S, Ctx);
+}
+
+// Update local variable definitions in variable map
+void VarMapBuilder::VisitBinaryOperator(BinaryOperator *BO) {
+  if (!BO->isAssignmentOp())
+    return;
+
+  Expr *LHSExp = BO->getLHS()->IgnoreParenCasts();
+
+  // Update the variable map and current context.
+  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LHSExp)) {
+    ValueDecl *VDec = DRE->getDecl();
+    if (Ctx.lookup(VDec)) {
+      if (BO->getOpcode() == BO_Assign)
+        Ctx = VMap->updateDefinition(VDec, BO->getRHS(), Ctx);
+      else
+        // FIXME -- handle compound assignment operators
+        Ctx = VMap->clearDefinition(VDec, Ctx);
+      VMap->saveContext(BO, Ctx);
+    }
+  }
+}
+
+
+// Computes the intersection of two contexts.  The intersection is the
+// set of variables which have the same definition in both contexts;
+// variables with different definitions are discarded.
+LocalVariableMap::Context
+LocalVariableMap::intersectContexts(Context C1, Context C2) {
+  Context Result = C1;
+  for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) {
+    NamedDecl *Dec = I.getKey();
+    unsigned i1 = I.getData();
+    const unsigned *i2 = C2.lookup(Dec);
+    if (!i2)             // variable doesn't exist on second path
+      Result = removeDefinition(Dec, Result);
+    else if (*i2 != i1)  // variable exists, but has different definition
+      Result = clearDefinition(Dec, Result);
+  }
+  return Result;
+}
+
+// For every variable in C, create a new variable that refers to the
+// definition in C.  Return a new context that contains these new variables.
+// (We use this for a naive implementation of SSA on loop back-edges.)
+LocalVariableMap::Context LocalVariableMap::createReferenceContext(Context C) {
+  Context Result = getEmptyContext();
+  for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) {
+    NamedDecl *Dec = I.getKey();
+    unsigned i = I.getData();
+    Result = addReference(Dec, i, Result);
+  }
+  return Result;
+}
+
+// This routine also takes the intersection of C1 and C2, but it does so by
+// altering the VarDefinitions.  C1 must be the result of an earlier call to
+// createReferenceContext.
+void LocalVariableMap::intersectBackEdge(Context C1, Context C2) {
+  for (Context::iterator I = C1.begin(), E = C1.end(); I != E; ++I) {
+    NamedDecl *Dec = I.getKey();
+    unsigned i1 = I.getData();
+    VarDefinition *VDef = &VarDefinitions[i1];
+    assert(VDef->isReference());
+
+    const unsigned *i2 = C2.lookup(Dec);
+    if (!i2 || (*i2 != i1))
+      VDef->Ref = 0;    // Mark this variable as undefined
+  }
+}
+
+
+// Traverse the CFG in topological order, so all predecessors of a block
+// (excluding back-edges) are visited before the block itself.  At
+// each point in the code, we calculate a Context, which holds the set of
+// variable definitions which are visible at that point in execution.
+// Visible variables are mapped to their definitions using an array that
+// contains all definitions.
+//
+// At join points in the CFG, the set is computed as the intersection of
+// the incoming sets along each edge, E.g.
+//
+//                       { Context                 | VarDefinitions }
+//   int x = 0;          { x -> x1                 | x1 = 0 }
+//   int y = 0;          { x -> x1, y -> y1        | y1 = 0, x1 = 0 }
+//   if (b) x = 1;       { x -> x2, y -> y1        | x2 = 1, y1 = 0, ... }
+//   else   x = 2;       { x -> x3, y -> y1        | x3 = 2, x2 = 1, ... }
+//   ...                 { y -> y1  (x is unknown) | x3 = 2, x2 = 1, ... }
+//
+// This is essentially a simpler and more naive version of the standard SSA
+// algorithm.  Those definitions that remain in the intersection are from blocks
+// that strictly dominate the current block.  We do not bother to insert proper
+// phi nodes, because they are not used in our analysis; instead, wherever
+// a phi node would be required, we simply remove that definition from the
+// context (E.g. x above).
+//
+// The initial traversal does not capture back-edges, so those need to be
+// handled on a separate pass.  Whenever the first pass encounters an
+// incoming back edge, it duplicates the context, creating new definitions
+// that refer back to the originals.  (These correspond to places where SSA
+// might have to insert a phi node.)  On the second pass, these definitions are
+// set to NULL if the the variable has changed on the back-edge (i.e. a phi
+// node was actually required.)  E.g.
+//
+//                       { Context           | VarDefinitions }
+//   int x = 0, y = 0;   { x -> x1, y -> y1  | y1 = 0, x1 = 0 }
+//   while (b)           { x -> x2, y -> y1  | [1st:] x2=x1; [2nd:] x2=NULL; }
+//     x = x+1;          { x -> x3, y -> y1  | x3 = x2 + 1, ... }
+//   ...                 { y -> y1           | x3 = 2, x2 = 1, ... }
+//
+void LocalVariableMap::traverseCFG(CFG *CFGraph,
+                                   PostOrderCFGView *SortedGraph,
+                                   std::vector<CFGBlockInfo> &BlockInfo) {
+  PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph);
+
+  CtxIndices.resize(CFGraph->getNumBlockIDs());
+
+  for (PostOrderCFGView::iterator I = SortedGraph->begin(),
+       E = SortedGraph->end(); I!= E; ++I) {
+    const CFGBlock *CurrBlock = *I;
+    int CurrBlockID = CurrBlock->getBlockID();
+    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID];
+
+    VisitedBlocks.insert(CurrBlock);
+
+    // Calculate the entry context for the current block
+    bool HasBackEdges = false;
+    bool CtxInit = true;
+    for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
+         PE  = CurrBlock->pred_end(); PI != PE; ++PI) {
+      // if *PI -> CurrBlock is a back edge, so skip it
+      if (*PI == 0 || !VisitedBlocks.alreadySet(*PI)) {
+        HasBackEdges = true;
+        continue;
+      }
+
+      int PrevBlockID = (*PI)->getBlockID();
+      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
+
+      if (CtxInit) {
+        CurrBlockInfo->EntryContext = PrevBlockInfo->ExitContext;
+        CtxInit = false;
+      }
+      else {
+        CurrBlockInfo->EntryContext =
+          intersectContexts(CurrBlockInfo->EntryContext,
+                            PrevBlockInfo->ExitContext);
+      }
+    }
+
+    // Duplicate the context if we have back-edges, so we can call
+    // intersectBackEdges later.
+    if (HasBackEdges)
+      CurrBlockInfo->EntryContext =
+        createReferenceContext(CurrBlockInfo->EntryContext);
+
+    // Create a starting context index for the current block
+    saveContext(0, CurrBlockInfo->EntryContext);
+    CurrBlockInfo->EntryIndex = getContextIndex();
+
+    // Visit all the statements in the basic block.
+    VarMapBuilder VMapBuilder(this, CurrBlockInfo->EntryContext);
+    for (CFGBlock::const_iterator BI = CurrBlock->begin(),
+         BE = CurrBlock->end(); BI != BE; ++BI) {
+      switch (BI->getKind()) {
+        case CFGElement::Statement: {
+          const CFGStmt *CS = cast<CFGStmt>(&*BI);
+          VMapBuilder.Visit(const_cast<Stmt*>(CS->getStmt()));
+          break;
+        }
+        default:
+          break;
+      }
+    }
+    CurrBlockInfo->ExitContext = VMapBuilder.Ctx;
+
+    // Mark variables on back edges as "unknown" if they've been changed.
+    for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
+         SE  = CurrBlock->succ_end(); SI != SE; ++SI) {
+      // if CurrBlock -> *SI is *not* a back edge
+      if (*SI == 0 || !VisitedBlocks.alreadySet(*SI))
+        continue;
+
+      CFGBlock *FirstLoopBlock = *SI;
+      Context LoopBegin = BlockInfo[FirstLoopBlock->getBlockID()].EntryContext;
+      Context LoopEnd   = CurrBlockInfo->ExitContext;
+      intersectBackEdge(LoopBegin, LoopEnd);
+    }
+  }
+
+  // Put an extra entry at the end of the indexed context array
+  unsigned exitID = CFGraph->getExit().getBlockID();
+  saveContext(0, BlockInfo[exitID].ExitContext);
+}
+
+/// Find the appropriate source locations to use when producing diagnostics for
+/// each block in the CFG.
+static void findBlockLocations(CFG *CFGraph,
+                               PostOrderCFGView *SortedGraph,
+                               std::vector<CFGBlockInfo> &BlockInfo) {
+  for (PostOrderCFGView::iterator I = SortedGraph->begin(),
+       E = SortedGraph->end(); I!= E; ++I) {
+    const CFGBlock *CurrBlock = *I;
+    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlock->getBlockID()];
+
+    // Find the source location of the last statement in the block, if the
+    // block is not empty.
+    if (const Stmt *S = CurrBlock->getTerminator()) {
+      CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc = S->getLocStart();
+    } else {
+      for (CFGBlock::const_reverse_iterator BI = CurrBlock->rbegin(),
+           BE = CurrBlock->rend(); BI != BE; ++BI) {
+        // FIXME: Handle other CFGElement kinds.
+        if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) {
+          CurrBlockInfo->ExitLoc = CS->getStmt()->getLocStart();
+          break;
+        }
+      }
+    }
+
+    if (!CurrBlockInfo->ExitLoc.isInvalid()) {
+      // This block contains at least one statement. Find the source location
+      // of the first statement in the block.
+      for (CFGBlock::const_iterator BI = CurrBlock->begin(),
+           BE = CurrBlock->end(); BI != BE; ++BI) {
+        // FIXME: Handle other CFGElement kinds.
+        if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) {
+          CurrBlockInfo->EntryLoc = CS->getStmt()->getLocStart();
+          break;
+        }
+      }
+    } else if (CurrBlock->pred_size() == 1 && *CurrBlock->pred_begin() &&
+               CurrBlock != &CFGraph->getExit()) {
+      // The block is empty, and has a single predecessor. Use its exit
+      // location.
+      CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc =
+          BlockInfo[(*CurrBlock->pred_begin())->getBlockID()].ExitLoc;
+    }
+  }
+}
+
+/// \brief Class which implements the core thread safety analysis routines.
+class ThreadSafetyAnalyzer {
+  friend class BuildLockset;
+
+  ThreadSafetyHandler &Handler;
+  Lockset::Factory    LocksetFactory;
+  LocalVariableMap    LocalVarMap;
+
+public:
+  ThreadSafetyAnalyzer(ThreadSafetyHandler &H) : Handler(H) {}
+
+  Lockset intersectAndWarn(const CFGBlockInfo &Block1, CFGBlockSide Side1,
+                           const CFGBlockInfo &Block2, CFGBlockSide Side2,
+                           LockErrorKind LEK);
+
+  Lockset addLock(Lockset &LSet, Expr *MutexExp, const NamedDecl *D,
+                  LockKind LK, SourceLocation Loc);
+
+  void runAnalysis(AnalysisDeclContext &AC);
+};
+
+
+/// \brief We use this class to visit different types of expressions in
+/// CFGBlocks, and build up the lockset.
+/// An expression may cause us to add or remove locks from the lockset, or else
+/// output error messages related to missing locks.
+/// FIXME: In future, we may be able to not inherit from a visitor.
+class BuildLockset : public StmtVisitor<BuildLockset> {
+  friend class ThreadSafetyAnalyzer;
+
+  ThreadSafetyHandler &Handler;
+  Lockset::Factory &LocksetFactory;
+  LocalVariableMap &LocalVarMap;
+
+  Lockset LSet;
+  LocalVariableMap::Context LVarCtx;
+  unsigned CtxIndex;
+
+  // Helper functions
+  void addLock(const MutexID &Mutex, const LockData &LDat);
+  void removeLock(const MutexID &Mutex, SourceLocation UnlockLoc);
+
+  template <class AttrType>
+  void addLocksToSet(LockKind LK, AttrType *Attr,
+                     Expr *Exp, NamedDecl *D, VarDecl *VD = 0);
+  void removeLocksFromSet(UnlockFunctionAttr *Attr,
+                          Expr *Exp, NamedDecl* FunDecl);
+
+  const ValueDecl *getValueDecl(Expr *Exp);
+  void warnIfMutexNotHeld (const NamedDecl *D, Expr *Exp, AccessKind AK,
+                           Expr *MutexExp, ProtectedOperationKind POK);
+  void checkAccess(Expr *Exp, AccessKind AK);
+  void checkDereference(Expr *Exp, AccessKind AK);
+  void handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD = 0);
+
+  template <class AttrType>
+  void addTrylock(LockKind LK, AttrType *Attr, Expr *Exp, NamedDecl *FunDecl,
+                  const CFGBlock* PredBlock, const CFGBlock *CurrBlock,
+                  Expr *BrE, bool Neg);
+  CallExpr* getTrylockCallExpr(Stmt *Cond, LocalVariableMap::Context C,
+                               bool &Negate);
+  void handleTrylock(Stmt *Cond, const CFGBlock* PredBlock,
+                     const CFGBlock *CurrBlock);
+
+  /// \brief Returns true if the lockset contains a lock, regardless of whether
+  /// the lock is held exclusively or shared.
+  bool locksetContains(const MutexID &Lock) const {
+    return LSet.lookup(Lock);
+  }
+
+  /// \brief Returns true if the lockset contains a lock with the passed in
+  /// locktype.
+  bool locksetContains(const MutexID &Lock, LockKind KindRequested) const {
+    const LockData *LockHeld = LSet.lookup(Lock);
+    return (LockHeld && KindRequested == LockHeld->LKind);
+  }
+
+  /// \brief Returns true if the lockset contains a lock with at least the
+  /// passed in locktype. So for example, if we pass in LK_Shared, this function
+  /// returns true if the lock is held LK_Shared or LK_Exclusive. If we pass in
+  /// LK_Exclusive, this function returns true if the lock is held LK_Exclusive.
+  bool locksetContainsAtLeast(const MutexID &Lock,
+                              LockKind KindRequested) const {
+    switch (KindRequested) {
+      case LK_Shared:
+        return locksetContains(Lock);
+      case LK_Exclusive:
+        return locksetContains(Lock, KindRequested);
+    }
+    llvm_unreachable("Unknown LockKind");
+  }
+
+public:
+  BuildLockset(ThreadSafetyAnalyzer *analyzer, CFGBlockInfo &Info)
+    : StmtVisitor<BuildLockset>(),
+      Handler(analyzer->Handler),
+      LocksetFactory(analyzer->LocksetFactory),
+      LocalVarMap(analyzer->LocalVarMap),
+      LSet(Info.EntrySet),
+      LVarCtx(Info.EntryContext),
+      CtxIndex(Info.EntryIndex)
+  {}
+
+  void VisitUnaryOperator(UnaryOperator *UO);
+  void VisitBinaryOperator(BinaryOperator *BO);
+  void VisitCastExpr(CastExpr *CE);
+  void VisitCallExpr(CallExpr *Exp);
+  void VisitCXXConstructExpr(CXXConstructExpr *Exp);
+  void VisitDeclStmt(DeclStmt *S);
+};
+
+/// \brief Add a new lock to the lockset, warning if the lock is already there.
+/// \param Mutex -- the Mutex expression for the lock
+/// \param LDat  -- the LockData for the lock
+void BuildLockset::addLock(const MutexID &Mutex, const LockData& LDat) {
+  // FIXME: deal with acquired before/after annotations.
+  // FIXME: Don't always warn when we have support for reentrant locks.
+  if (locksetContains(Mutex))
+    Handler.handleDoubleLock(Mutex.getName(), LDat.AcquireLoc);
+  else
+    LSet = LocksetFactory.add(LSet, Mutex, LDat);
+}
+
+/// \brief Remove a lock from the lockset, warning if the lock is not there.
+/// \param LockExp The lock expression corresponding to the lock to be removed
+/// \param UnlockLoc The source location of the unlock (only used in error msg)
+void BuildLockset::removeLock(const MutexID &Mutex, SourceLocation UnlockLoc) {
+  const LockData *LDat = LSet.lookup(Mutex);
+  if (!LDat)
+    Handler.handleUnmatchedUnlock(Mutex.getName(), UnlockLoc);
+  else {
+    // For scoped-lockable vars, remove the mutex associated with this var.
+    if (LDat->UnderlyingMutex.isValid())
+      removeLock(LDat->UnderlyingMutex, UnlockLoc);
+    LSet = LocksetFactory.remove(LSet, Mutex);
+  }
+}
+
+/// \brief This function, parameterized by an attribute type, is used to add a
+/// set of locks specified as attribute arguments to the lockset.
+template <typename AttrType>
+void BuildLockset::addLocksToSet(LockKind LK, AttrType *Attr,
+                                 Expr *Exp, NamedDecl* FunDecl, VarDecl *VD) {
+  typedef typename AttrType::args_iterator iterator_type;
+
+  SourceLocation ExpLocation = Exp->getExprLoc();
+
+  // Figure out if we're calling the constructor of scoped lockable class
+  bool isScopedVar = false;
+  if (VD) {
+    if (CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FunDecl)) {
+      CXXRecordDecl* PD = CD->getParent();
+      if (PD && PD->getAttr<ScopedLockableAttr>())
+        isScopedVar = true;
+    }
+  }
+
+  if (Attr->args_size() == 0) {
+    // The mutex held is the "this" object.
+    MutexID Mutex(0, Exp, FunDecl);
+    if (!Mutex.isValid())
+      MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl);
+    else
+      addLock(Mutex, LockData(ExpLocation, LK));
+    return;
+  }
+
+  for (iterator_type I=Attr->args_begin(), E=Attr->args_end(); I != E; ++I) {
+    MutexID Mutex(*I, Exp, FunDecl);
+    if (!Mutex.isValid())
+      MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl);
+    else {
+      addLock(Mutex, LockData(ExpLocation, LK));
+      if (isScopedVar) {
+        // For scoped lockable vars, map this var to its underlying mutex.
+        DeclRefExpr DRE(VD, false, VD->getType(), VK_LValue, VD->getLocation());
+        MutexID SMutex(&DRE, 0, 0);
+        addLock(SMutex, LockData(VD->getLocation(), LK, Mutex));
+      }
+    }
+  }
+}
+
+/// \brief This function removes a set of locks specified as attribute
+/// arguments from the lockset.
+void BuildLockset::removeLocksFromSet(UnlockFunctionAttr *Attr,
+                                      Expr *Exp, NamedDecl* FunDecl) {
+  SourceLocation ExpLocation;
+  if (Exp) ExpLocation = Exp->getExprLoc();
+
+  if (Attr->args_size() == 0) {
+    // The mutex held is the "this" object.
+    MutexID Mu(0, Exp, FunDecl);
+    if (!Mu.isValid())
+      MutexID::warnInvalidLock(Handler, 0, Exp, FunDecl);
+    else
+      removeLock(Mu, ExpLocation);
+    return;
+  }
+
+  for (UnlockFunctionAttr::args_iterator I = Attr->args_begin(),
+       E = Attr->args_end(); I != E; ++I) {
+    MutexID Mutex(*I, Exp, FunDecl);
+    if (!Mutex.isValid())
+      MutexID::warnInvalidLock(Handler, *I, Exp, FunDecl);
+    else
+      removeLock(Mutex, ExpLocation);
+  }
+}
+
+/// \brief Gets the value decl pointer from DeclRefExprs or MemberExprs
+const ValueDecl *BuildLockset::getValueDecl(Expr *Exp) {
+  if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Exp))
+    return DR->getDecl();
+
+  if (const MemberExpr *ME = dyn_cast<MemberExpr>(Exp))
+    return ME->getMemberDecl();
+
+  return 0;
+}
+
+/// \brief Warn if the LSet does not contain a lock sufficient to protect access
+/// of at least the passed in AccessKind.
+void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, Expr *Exp,
+                                      AccessKind AK, Expr *MutexExp,
+                                      ProtectedOperationKind POK) {
+  LockKind LK = getLockKindFromAccessKind(AK);
+
+  MutexID Mutex(MutexExp, Exp, D);
+  if (!Mutex.isValid())
+    MutexID::warnInvalidLock(Handler, MutexExp, Exp, D);
+  else if (!locksetContainsAtLeast(Mutex, LK))
+    Handler.handleMutexNotHeld(D, POK, Mutex.getName(), LK, Exp->getExprLoc());
+}
+
+/// \brief This method identifies variable dereferences and checks pt_guarded_by
+/// and pt_guarded_var annotations. Note that we only check these annotations
+/// at the time a pointer is dereferenced.
+/// FIXME: We need to check for other types of pointer dereferences
+/// (e.g. [], ->) and deal with them here.
+/// \param Exp An expression that has been read or written.
+void BuildLockset::checkDereference(Expr *Exp, AccessKind AK) {
+  UnaryOperator *UO = dyn_cast<UnaryOperator>(Exp);
+  if (!UO || UO->getOpcode() != clang::UO_Deref)
+    return;
+  Exp = UO->getSubExpr()->IgnoreParenCasts();
+
+  const ValueDecl *D = getValueDecl(Exp);
+  if(!D || !D->hasAttrs())
+    return;
+
+  if (D->getAttr<PtGuardedVarAttr>() && LSet.isEmpty())
+    Handler.handleNoMutexHeld(D, POK_VarDereference, AK, Exp->getExprLoc());
+
+  const AttrVec &ArgAttrs = D->getAttrs();
+  for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
+    if (PtGuardedByAttr *PGBAttr = dyn_cast<PtGuardedByAttr>(ArgAttrs[i]))
+      warnIfMutexNotHeld(D, Exp, AK, PGBAttr->getArg(), POK_VarDereference);
+}
+
+/// \brief Checks guarded_by and guarded_var attributes.
+/// Whenever we identify an access (read or write) of a DeclRefExpr or
+/// MemberExpr, we need to check whether there are any guarded_by or
+/// guarded_var attributes, and make sure we hold the appropriate mutexes.
+void BuildLockset::checkAccess(Expr *Exp, AccessKind AK) {
+  const ValueDecl *D = getValueDecl(Exp);
+  if(!D || !D->hasAttrs())
+    return;
+
+  if (D->getAttr<GuardedVarAttr>() && LSet.isEmpty())
+    Handler.handleNoMutexHeld(D, POK_VarAccess, AK, Exp->getExprLoc());
+
+  const AttrVec &ArgAttrs = D->getAttrs();
+  for(unsigned i = 0, Size = ArgAttrs.size(); i < Size; ++i)
+    if (GuardedByAttr *GBAttr = dyn_cast<GuardedByAttr>(ArgAttrs[i]))
+      warnIfMutexNotHeld(D, Exp, AK, GBAttr->getArg(), POK_VarAccess);
+}
+
+/// \brief Process a function call, method call, constructor call,
+/// or destructor call.  This involves looking at the attributes on the
+/// corresponding function/method/constructor/destructor, issuing warnings,
+/// and updating the locksets accordingly.
+///
+/// FIXME: For classes annotated with one of the guarded annotations, we need
+/// to treat const method calls as reads and non-const method calls as writes,
+/// and check that the appropriate locks are held. Non-const method calls with
+/// the same signature as const method calls can be also treated as reads.
+///
+/// FIXME: We need to also visit CallExprs to catch/check global functions.
+///
+/// FIXME: Do not flag an error for member variables accessed in constructors/
+/// destructors
+void BuildLockset::handleCall(Expr *Exp, NamedDecl *D, VarDecl *VD) {
+  AttrVec &ArgAttrs = D->getAttrs();
+  for(unsigned i = 0; i < ArgAttrs.size(); ++i) {
+    Attr *Attr = ArgAttrs[i];
+    switch (Attr->getKind()) {
+      // When we encounter an exclusive lock function, we need to add the lock
+      // to our lockset with kind exclusive.
+      case attr::ExclusiveLockFunction: {
+        ExclusiveLockFunctionAttr *A = cast<ExclusiveLockFunctionAttr>(Attr);
+        addLocksToSet(LK_Exclusive, A, Exp, D, VD);
+        break;
+      }
+
+      // When we encounter a shared lock function, we need to add the lock
+      // to our lockset with kind shared.
+      case attr::SharedLockFunction: {
+        SharedLockFunctionAttr *A = cast<SharedLockFunctionAttr>(Attr);
+        addLocksToSet(LK_Shared, A, Exp, D, VD);
+        break;
+      }
+
+      // When we encounter an unlock function, we need to remove unlocked
+      // mutexes from the lockset, and flag a warning if they are not there.
+      case attr::UnlockFunction: {
+        UnlockFunctionAttr *UFAttr = cast<UnlockFunctionAttr>(Attr);
+        removeLocksFromSet(UFAttr, Exp, D);
+        break;
+      }
+
+      case attr::ExclusiveLocksRequired: {
+        ExclusiveLocksRequiredAttr *ELRAttr =
+            cast<ExclusiveLocksRequiredAttr>(Attr);
+
+        for (ExclusiveLocksRequiredAttr::args_iterator
+             I = ELRAttr->args_begin(), E = ELRAttr->args_end(); I != E; ++I)
+          warnIfMutexNotHeld(D, Exp, AK_Written, *I, POK_FunctionCall);
+        break;
+      }
+
+      case attr::SharedLocksRequired: {
+        SharedLocksRequiredAttr *SLRAttr = cast<SharedLocksRequiredAttr>(Attr);
+
+        for (SharedLocksRequiredAttr::args_iterator I = SLRAttr->args_begin(),
+             E = SLRAttr->args_end(); I != E; ++I)
+          warnIfMutexNotHeld(D, Exp, AK_Read, *I, POK_FunctionCall);
+        break;
+      }
+
+      case attr::LocksExcluded: {
+        LocksExcludedAttr *LEAttr = cast<LocksExcludedAttr>(Attr);
+        for (LocksExcludedAttr::args_iterator I = LEAttr->args_begin(),
+            E = LEAttr->args_end(); I != E; ++I) {
+          MutexID Mutex(*I, Exp, D);
+          if (!Mutex.isValid())
+            MutexID::warnInvalidLock(Handler, *I, Exp, D);
+          else if (locksetContains(Mutex))
+            Handler.handleFunExcludesLock(D->getName(), Mutex.getName(),
+                                          Exp->getExprLoc());
+        }
+        break;
+      }
+
+      // Ignore other (non thread-safety) attributes
+      default:
+        break;
+    }
+  }
+}
+
+
+/// \brief Add lock to set, if the current block is in the taken branch of a
+/// trylock.
+template <class AttrType>
+void BuildLockset::addTrylock(LockKind LK, AttrType *Attr, Expr *Exp,
+                              NamedDecl *FunDecl, const CFGBlock *PredBlock,
+                              const CFGBlock *CurrBlock, Expr *BrE, bool Neg) {
+  // Find out which branch has the lock
+  bool branch = 0;
+  if (CXXBoolLiteralExpr *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE)) {
+    branch = BLE->getValue();
+  }
+  else if (IntegerLiteral *ILE = dyn_cast_or_null<IntegerLiteral>(BrE)) {
+    branch = ILE->getValue().getBoolValue();
+  }
+  int branchnum = branch ? 0 : 1;
+  if (Neg) branchnum = !branchnum;
+
+  // If we've taken the trylock branch, then add the lock
+  int i = 0;
+  for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(),
+       SE = PredBlock->succ_end(); SI != SE && i < 2; ++SI, ++i) {
+    if (*SI == CurrBlock && i == branchnum) {
+      addLocksToSet(LK, Attr, Exp, FunDecl, 0);
+    }
+  }
+}
+
+
+// If Cond can be traced back to a function call, return the call expression.
+// The negate variable should be called with false, and will be set to true
+// if the function call is negated, e.g. if (!mu.tryLock(...))
+CallExpr* BuildLockset::getTrylockCallExpr(Stmt *Cond,
+                               LocalVariableMap::Context C,
+                               bool &Negate) {
+  if (!Cond)
+    return 0;
+
+  if (CallExpr *CallExp = dyn_cast<CallExpr>(Cond)) {
+    return CallExp;
+  }
+  else if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(Cond)) {
+    return getTrylockCallExpr(CE->getSubExpr(), C, Negate);
+  }
+  else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Cond)) {
+    Expr *E = LocalVarMap.lookupExpr(DRE->getDecl(), C);
+    return getTrylockCallExpr(E, C, Negate);
+  }
+  else if (UnaryOperator *UOP = dyn_cast<UnaryOperator>(Cond)) {
+    if (UOP->getOpcode() == UO_LNot) {
+      Negate = !Negate;
+      return getTrylockCallExpr(UOP->getSubExpr(), C, Negate);
+    }
+  }
+  // FIXME -- handle && and || as well.
+  return NULL;
+}
+
+
+/// \brief Process a conditional branch from a previous block to the current
+/// block, looking for trylock calls.
+void BuildLockset::handleTrylock(Stmt *Cond, const CFGBlock *PredBlock,
+                                 const CFGBlock *CurrBlock) {
+  bool Negate = false;
+  CallExpr *Exp = getTrylockCallExpr(Cond, LVarCtx, Negate);
+  if (!Exp)
+    return;
+
+  NamedDecl *FunDecl = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl());
+  if(!FunDecl || !FunDecl->hasAttrs())
+    return;
+
+  // If the condition is a call to a Trylock function, then grab the attributes
+  AttrVec &ArgAttrs = FunDecl->getAttrs();
+  for (unsigned i = 0; i < ArgAttrs.size(); ++i) {
+    Attr *Attr = ArgAttrs[i];
+    switch (Attr->getKind()) {
+      case attr::ExclusiveTrylockFunction: {
+        ExclusiveTrylockFunctionAttr *A =
+          cast<ExclusiveTrylockFunctionAttr>(Attr);
+        addTrylock(LK_Exclusive, A, Exp, FunDecl, PredBlock, CurrBlock,
+                   A->getSuccessValue(), Negate);
+        break;
+      }
+      case attr::SharedTrylockFunction: {
+        SharedTrylockFunctionAttr *A =
+          cast<SharedTrylockFunctionAttr>(Attr);
+        addTrylock(LK_Shared, A, Exp, FunDecl, PredBlock, CurrBlock,
+                   A->getSuccessValue(), Negate);
+        break;
+      }
+      default:
+        break;
+    }
+  }
+}
+
+
+/// \brief For unary operations which read and write a variable, we need to
+/// check whether we hold any required mutexes. Reads are checked in
+/// VisitCastExpr.
+void BuildLockset::VisitUnaryOperator(UnaryOperator *UO) {
+  switch (UO->getOpcode()) {
+    case clang::UO_PostDec:
+    case clang::UO_PostInc:
+    case clang::UO_PreDec:
+    case clang::UO_PreInc: {
+      Expr *SubExp = UO->getSubExpr()->IgnoreParenCasts();
+      checkAccess(SubExp, AK_Written);
+      checkDereference(SubExp, AK_Written);
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+/// For binary operations which assign to a variable (writes), we need to check
+/// whether we hold any required mutexes.
+/// FIXME: Deal with non-primitive types.
+void BuildLockset::VisitBinaryOperator(BinaryOperator *BO) {
+  if (!BO->isAssignmentOp())
+    return;
+
+  // adjust the context
+  LVarCtx = LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx);
+
+  Expr *LHSExp = BO->getLHS()->IgnoreParenCasts();
+  checkAccess(LHSExp, AK_Written);
+  checkDereference(LHSExp, AK_Written);
+}
+
+/// Whenever we do an LValue to Rvalue cast, we are reading a variable and
+/// need to ensure we hold any required mutexes.
+/// FIXME: Deal with non-primitive types.
+void BuildLockset::VisitCastExpr(CastExpr *CE) {
+  if (CE->getCastKind() != CK_LValueToRValue)
+    return;
+  Expr *SubExp = CE->getSubExpr()->IgnoreParenCasts();
+  checkAccess(SubExp, AK_Read);
+  checkDereference(SubExp, AK_Read);
+}
+
+
+void BuildLockset::VisitCallExpr(CallExpr *Exp) {
+  NamedDecl *D = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl());
+  if(!D || !D->hasAttrs())
+    return;
+  handleCall(Exp, D);
+}
+
+void BuildLockset::VisitCXXConstructExpr(CXXConstructExpr *Exp) {
+  // FIXME -- only handles constructors in DeclStmt below.
+}
+
+void BuildLockset::VisitDeclStmt(DeclStmt *S) {
+  // adjust the context
+  LVarCtx = LocalVarMap.getNextContext(CtxIndex, S, LVarCtx);
+
+  DeclGroupRef DGrp = S->getDeclGroup();
+  for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) {
+    Decl *D = *I;
+    if (VarDecl *VD = dyn_cast_or_null<VarDecl>(D)) {
+      Expr *E = VD->getInit();
+      if (CXXConstructExpr *CE = dyn_cast_or_null<CXXConstructExpr>(E)) {
+        NamedDecl *CtorD = dyn_cast_or_null<NamedDecl>(CE->getConstructor());
+        if (!CtorD || !CtorD->hasAttrs())
+          return;
+        handleCall(CE, CtorD, VD);
+      }
+    }
+  }
+}
+
+
+/// \brief Compute the intersection of two locksets and issue warnings for any
+/// locks in the symmetric difference.
+///
+/// This function is used at a merge point in the CFG when comparing the lockset
+/// of each branch being merged. For example, given the following sequence:
+/// A; if () then B; else C; D; we need to check that the lockset after B and C
+/// are the same. In the event of a difference, we use the intersection of these
+/// two locksets at the start of D.
+Lockset ThreadSafetyAnalyzer::intersectAndWarn(const CFGBlockInfo &Block1,
+                                               CFGBlockSide Side1,
+                                               const CFGBlockInfo &Block2,
+                                               CFGBlockSide Side2,
+                                               LockErrorKind LEK) {
+  Lockset LSet1 = Block1.getSet(Side1);
+  Lockset LSet2 = Block2.getSet(Side2);
+
+  Lockset Intersection = LSet1;
+  for (Lockset::iterator I = LSet2.begin(), E = LSet2.end(); I != E; ++I) {
+    const MutexID &LSet2Mutex = I.getKey();
+    const LockData &LSet2LockData = I.getData();
+    if (const LockData *LD = LSet1.lookup(LSet2Mutex)) {
+      if (LD->LKind != LSet2LockData.LKind) {
+        Handler.handleExclusiveAndShared(LSet2Mutex.getName(),
+                                         LSet2LockData.AcquireLoc,
+                                         LD->AcquireLoc);
+        if (LD->LKind != LK_Exclusive)
+          Intersection = LocksetFactory.add(Intersection, LSet2Mutex,
+                                            LSet2LockData);
+      }
+    } else {
+      Handler.handleMutexHeldEndOfScope(LSet2Mutex.getName(),
+                                        LSet2LockData.AcquireLoc,
+                                        Block1.getLocation(Side1), LEK);
+    }
+  }
+
+  for (Lockset::iterator I = LSet1.begin(), E = LSet1.end(); I != E; ++I) {
+    if (!LSet2.contains(I.getKey())) {
+      const MutexID &Mutex = I.getKey();
+      const LockData &MissingLock = I.getData();
+      Handler.handleMutexHeldEndOfScope(Mutex.getName(),
+                                        MissingLock.AcquireLoc,
+                                        Block2.getLocation(Side2), LEK);
+      Intersection = LocksetFactory.remove(Intersection, Mutex);
+    }
+  }
+  return Intersection;
+}
+
+Lockset ThreadSafetyAnalyzer::addLock(Lockset &LSet, Expr *MutexExp,
+                                      const NamedDecl *D,
+                                      LockKind LK, SourceLocation Loc) {
+  MutexID Mutex(MutexExp, 0, D);
+  if (!Mutex.isValid()) {
+    MutexID::warnInvalidLock(Handler, MutexExp, 0, D);
+    return LSet;
+  }
+  LockData NewLock(Loc, LK);
+  return LocksetFactory.add(LSet, Mutex, NewLock);
+}
+
+/// \brief Check a function's CFG for thread-safety violations.
+///
+/// We traverse the blocks in the CFG, compute the set of mutexes that are held
+/// at the end of each block, and issue warnings for thread safety violations.
+/// Each block in the CFG is traversed exactly once.
+void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) {
+  CFG *CFGraph = AC.getCFG();
+  if (!CFGraph) return;
+  const NamedDecl *D = dyn_cast_or_null<NamedDecl>(AC.getDecl());
+
+  if (!D)
+    return;  // Ignore anonymous functions for now.
+  if (D->getAttr<NoThreadSafetyAnalysisAttr>())
+    return;
+  // FIXME: Do something a bit more intelligent inside constructor and
+  // destructor code.  Constructors and destructors must assume unique access
+  // to 'this', so checks on member variable access is disabled, but we should
+  // still enable checks on other objects.
+  if (isa<CXXConstructorDecl>(D))
+    return;  // Don't check inside constructors.
+  if (isa<CXXDestructorDecl>(D))
+    return;  // Don't check inside destructors.
+
+  std::vector<CFGBlockInfo> BlockInfo(CFGraph->getNumBlockIDs(),
+    CFGBlockInfo::getEmptyBlockInfo(LocksetFactory, LocalVarMap));
+
+  // We need to explore the CFG via a "topological" ordering.
+  // That way, we will be guaranteed to have information about required
+  // predecessor locksets when exploring a new block.
+  PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>();
+  PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph);
+
+  // Compute SSA names for local variables
+  LocalVarMap.traverseCFG(CFGraph, SortedGraph, BlockInfo);
+
+  // Fill in source locations for all CFGBlocks.
+  findBlockLocations(CFGraph, SortedGraph, BlockInfo);
+
+  // Add locks from exclusive_locks_required and shared_locks_required
+  // to initial lockset. Also turn off checking for lock and unlock functions.
+  // FIXME: is there a more intelligent way to check lock/unlock functions?
+  if (!SortedGraph->empty() && D->hasAttrs()) {
+    const CFGBlock *FirstBlock = *SortedGraph->begin();
+    Lockset &InitialLockset = BlockInfo[FirstBlock->getBlockID()].EntrySet;
+    const AttrVec &ArgAttrs = D->getAttrs();
+    for (unsigned i = 0; i < ArgAttrs.size(); ++i) {
+      Attr *Attr = ArgAttrs[i];
+      SourceLocation AttrLoc = Attr->getLocation();
+      if (SharedLocksRequiredAttr *SLRAttr
+            = dyn_cast<SharedLocksRequiredAttr>(Attr)) {
+        for (SharedLocksRequiredAttr::args_iterator
+             SLRIter = SLRAttr->args_begin(),
+             SLREnd = SLRAttr->args_end(); SLRIter != SLREnd; ++SLRIter)
+          InitialLockset = addLock(InitialLockset,
+                                   *SLRIter, D, LK_Shared,
+                                   AttrLoc);
+      } else if (ExclusiveLocksRequiredAttr *ELRAttr
+                   = dyn_cast<ExclusiveLocksRequiredAttr>(Attr)) {
+        for (ExclusiveLocksRequiredAttr::args_iterator
+             ELRIter = ELRAttr->args_begin(),
+             ELREnd = ELRAttr->args_end(); ELRIter != ELREnd; ++ELRIter)
+          InitialLockset = addLock(InitialLockset,
+                                   *ELRIter, D, LK_Exclusive,
+                                   AttrLoc);
+      } else if (isa<UnlockFunctionAttr>(Attr)) {
+        // Don't try to check unlock functions for now
+        return;
+      } else if (isa<ExclusiveLockFunctionAttr>(Attr)) {
+        // Don't try to check lock functions for now
+        return;
+      } else if (isa<SharedLockFunctionAttr>(Attr)) {
+        // Don't try to check lock functions for now
+        return;
+      }
+    }
+  }
+
+  for (PostOrderCFGView::iterator I = SortedGraph->begin(),
+       E = SortedGraph->end(); I!= E; ++I) {
+    const CFGBlock *CurrBlock = *I;
+    int CurrBlockID = CurrBlock->getBlockID();
+    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID];
+
+    // Use the default initial lockset in case there are no predecessors.
+    VisitedBlocks.insert(CurrBlock);
+
+    // Iterate through the predecessor blocks and warn if the lockset for all
+    // predecessors is not the same. We take the entry lockset of the current
+    // block to be the intersection of all previous locksets.
+    // FIXME: By keeping the intersection, we may output more errors in future
+    // for a lock which is not in the intersection, but was in the union. We
+    // may want to also keep the union in future. As an example, let's say
+    // the intersection contains Mutex L, and the union contains L and M.
+    // Later we unlock M. At this point, we would output an error because we
+    // never locked M; although the real error is probably that we forgot to
+    // lock M on all code paths. Conversely, let's say that later we lock M.
+    // In this case, we should compare against the intersection instead of the
+    // union because the real error is probably that we forgot to unlock M on
+    // all code paths.
+    bool LocksetInitialized = false;
+    llvm::SmallVector<CFGBlock*, 8> SpecialBlocks;
+    for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
+         PE  = CurrBlock->pred_end(); PI != PE; ++PI) {
+
+      // if *PI -> CurrBlock is a back edge
+      if (*PI == 0 || !VisitedBlocks.alreadySet(*PI))
+        continue;
+
+      // Ignore edges from blocks that can't return.
+      if ((*PI)->hasNoReturnElement())
+        continue;
+
+      // If the previous block ended in a 'continue' or 'break' statement, then
+      // a difference in locksets is probably due to a bug in that block, rather
+      // than in some other predecessor. In that case, keep the other
+      // predecessor's lockset.
+      if (const Stmt *Terminator = (*PI)->getTerminator()) {
+        if (isa<ContinueStmt>(Terminator) || isa<BreakStmt>(Terminator)) {
+          SpecialBlocks.push_back(*PI);
+          continue;
+        }
+      }
+
+      int PrevBlockID = (*PI)->getBlockID();
+      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
+
+      if (!LocksetInitialized) {
+        CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet;
+        LocksetInitialized = true;
+      } else {
+        CurrBlockInfo->EntrySet =
+          intersectAndWarn(*CurrBlockInfo, CBS_Entry,
+                           *PrevBlockInfo, CBS_Exit,
+                           LEK_LockedSomePredecessors);
+      }
+    }
+
+    // Process continue and break blocks. Assume that the lockset for the
+    // resulting block is unaffected by any discrepancies in them.
+    for (unsigned SpecialI = 0, SpecialN = SpecialBlocks.size();
+         SpecialI < SpecialN; ++SpecialI) {
+      CFGBlock *PrevBlock = SpecialBlocks[SpecialI];
+      int PrevBlockID = PrevBlock->getBlockID();
+      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
+
+      if (!LocksetInitialized) {
+        CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet;
+        LocksetInitialized = true;
+      } else {
+        // Determine whether this edge is a loop terminator for diagnostic
+        // purposes. FIXME: A 'break' statement might be a loop terminator, but
+        // it might also be part of a switch. Also, a subsequent destructor
+        // might add to the lockset, in which case the real issue might be a
+        // double lock on the other path.
+        const Stmt *Terminator = PrevBlock->getTerminator();
+        bool IsLoop = Terminator && isa<ContinueStmt>(Terminator);
+
+        // Do not update EntrySet.
+        intersectAndWarn(*CurrBlockInfo, CBS_Entry, *PrevBlockInfo, CBS_Exit,
+                         IsLoop ? LEK_LockedSomeLoopIterations
+                                : LEK_LockedSomePredecessors);
+      }
+    }
+
+    BuildLockset LocksetBuilder(this, *CurrBlockInfo);
+    CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
+                                  PE = CurrBlock->pred_end();
+    if (PI != PE) {
+      // If the predecessor ended in a branch, then process any trylocks.
+      // FIXME -- check to make sure there's only one predecessor.
+      if (Stmt *TCE = (*PI)->getTerminatorCondition()) {
+        LocksetBuilder.handleTrylock(TCE, *PI, CurrBlock);
+      }
+    }
+
+    // Visit all the statements in the basic block.
+    for (CFGBlock::const_iterator BI = CurrBlock->begin(),
+         BE = CurrBlock->end(); BI != BE; ++BI) {
+      switch (BI->getKind()) {
+        case CFGElement::Statement: {
+          const CFGStmt *CS = cast<CFGStmt>(&*BI);
+          LocksetBuilder.Visit(const_cast<Stmt*>(CS->getStmt()));
+          break;
+        }
+        // Ignore BaseDtor, MemberDtor, and TemporaryDtor for now.
+        case CFGElement::AutomaticObjectDtor: {
+          const CFGAutomaticObjDtor *AD = cast<CFGAutomaticObjDtor>(&*BI);
+          CXXDestructorDecl *DD = const_cast<CXXDestructorDecl*>(
+            AD->getDestructorDecl(AC.getASTContext()));
+          if (!DD->hasAttrs())
+            break;
+
+          // Create a dummy expression,
+          VarDecl *VD = const_cast<VarDecl*>(AD->getVarDecl());
+          DeclRefExpr DRE(VD, false, VD->getType(), VK_LValue,
+                          AD->getTriggerStmt()->getLocEnd());
+          LocksetBuilder.handleCall(&DRE, DD);
+          break;
+        }
+        default:
+          break;
+      }
+    }
+    CurrBlockInfo->ExitSet = LocksetBuilder.LSet;
+
+    // For every back edge from CurrBlock (the end of the loop) to another block
+    // (FirstLoopBlock) we need to check that the Lockset of Block is equal to
+    // the one held at the beginning of FirstLoopBlock. We can look up the
+    // Lockset held at the beginning of FirstLoopBlock in the EntryLockSets map.
+    for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
+         SE  = CurrBlock->succ_end(); SI != SE; ++SI) {
+
+      // if CurrBlock -> *SI is *not* a back edge
+      if (*SI == 0 || !VisitedBlocks.alreadySet(*SI))
+        continue;
+
+      CFGBlock *FirstLoopBlock = *SI;
+      CFGBlockInfo &PreLoop = BlockInfo[FirstLoopBlock->getBlockID()];
+      CFGBlockInfo &LoopEnd = BlockInfo[CurrBlockID];
+      intersectAndWarn(LoopEnd, CBS_Exit, PreLoop, CBS_Entry,
+                       LEK_LockedSomeLoopIterations);
+    }
+  }
+
+  CFGBlockInfo &Initial = BlockInfo[CFGraph->getEntry().getBlockID()];
+  CFGBlockInfo &Final = BlockInfo[CFGraph->getExit().getBlockID()];
+
+  // FIXME: Should we call this function for all blocks which exit the function?
+  intersectAndWarn(Initial, CBS_Entry, Final, CBS_Exit,
+                   LEK_LockedAtEndOfFunction);
+}
+
+} // end anonymous namespace
+
+
+namespace clang {
+namespace thread_safety {
+
+/// \brief Check a function's CFG for thread-safety violations.
+///
+/// We traverse the blocks in the CFG, compute the set of mutexes that are held
+/// at the end of each block, and issue warnings for thread safety violations.
+/// Each block in the CFG is traversed exactly once.
+void runThreadSafetyAnalysis(AnalysisDeclContext &AC,
+                             ThreadSafetyHandler &Handler) {
+  ThreadSafetyAnalyzer Analyzer(Handler);
+  Analyzer.runAnalysis(AC);
+}
+
+/// \brief Helper function that returns a LockKind required for the given level
+/// of access.
+LockKind getLockKindFromAccessKind(AccessKind AK) {
+  switch (AK) {
+    case AK_Read :
+      return LK_Shared;
+    case AK_Written :
+      return LK_Exclusive;
+  }
+  llvm_unreachable("Unknown AccessKind");
+}
+
+}} // end namespace clang::thread_safety
diff --git a/clang/lib/Analysis/UninitializedValues.cpp b/clang/lib/Analysis/UninitializedValues.cpp
new file mode 100644
index 0000000..1c7e6b6
--- /dev/null
+++ b/clang/lib/Analysis/UninitializedValues.cpp
@@ -0,0 +1,725 @@
+//==- UninitializedValues.cpp - Find Uninitialized Values -------*- C++ --*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements uninitialized values analysis for source-level CFGs.
+//
+//===----------------------------------------------------------------------===//
+
+#include <utility>
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/PackedVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "clang/AST/Decl.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/Visitors/CFGRecStmtDeclVisitor.h"
+#include "clang/Analysis/Analyses/UninitializedValues.h"
+#include "llvm/Support/SaveAndRestore.h"
+
+using namespace clang;
+
+static bool isTrackedVar(const VarDecl *vd, const DeclContext *dc) {
+  if (vd->isLocalVarDecl() && !vd->hasGlobalStorage() &&
+      !vd->isExceptionVariable() &&
+      vd->getDeclContext() == dc) {
+    QualType ty = vd->getType();
+    return ty->isScalarType() || ty->isVectorType();
+  }
+  return false;
+}
+
+//------------------------------------------------------------------------====//
+// DeclToIndex: a mapping from Decls we track to value indices.
+//====------------------------------------------------------------------------//
+
+namespace {
+class DeclToIndex {
+  llvm::DenseMap<const VarDecl *, unsigned> map;
+public:
+  DeclToIndex() {}
+  
+  /// Compute the actual mapping from declarations to bits.
+  void computeMap(const DeclContext &dc);
+  
+  /// Return the number of declarations in the map.
+  unsigned size() const { return map.size(); }
+  
+  /// Returns the bit vector index for a given declaration.
+  llvm::Optional<unsigned> getValueIndex(const VarDecl *d) const;
+};
+}
+
+void DeclToIndex::computeMap(const DeclContext &dc) {
+  unsigned count = 0;
+  DeclContext::specific_decl_iterator<VarDecl> I(dc.decls_begin()),
+                                               E(dc.decls_end());
+  for ( ; I != E; ++I) {
+    const VarDecl *vd = *I;
+    if (isTrackedVar(vd, &dc))
+      map[vd] = count++;
+  }
+}
+
+llvm::Optional<unsigned> DeclToIndex::getValueIndex(const VarDecl *d) const {
+  llvm::DenseMap<const VarDecl *, unsigned>::const_iterator I = map.find(d);
+  if (I == map.end())
+    return llvm::Optional<unsigned>();
+  return I->second;
+}
+
+//------------------------------------------------------------------------====//
+// CFGBlockValues: dataflow values for CFG blocks.
+//====------------------------------------------------------------------------//
+
+// These values are defined in such a way that a merge can be done using
+// a bitwise OR.
+enum Value { Unknown = 0x0,         /* 00 */
+             Initialized = 0x1,     /* 01 */
+             Uninitialized = 0x2,   /* 10 */
+             MayUninitialized = 0x3 /* 11 */ };
+
+static bool isUninitialized(const Value v) {
+  return v >= Uninitialized;
+}
+static bool isAlwaysUninit(const Value v) {
+  return v == Uninitialized;
+}
+
+namespace {
+
+typedef llvm::PackedVector<Value, 2> ValueVector;
+typedef std::pair<ValueVector *, ValueVector *> BVPair;
+
+class CFGBlockValues {
+  const CFG &cfg;
+  BVPair *vals;
+  ValueVector scratch;
+  DeclToIndex declToIndex;
+  
+  ValueVector &lazyCreate(ValueVector *&bv);
+public:
+  CFGBlockValues(const CFG &cfg);
+  ~CFGBlockValues();
+  
+  unsigned getNumEntries() const { return declToIndex.size(); }
+  
+  void computeSetOfDeclarations(const DeclContext &dc);  
+  ValueVector &getValueVector(const CFGBlock *block,
+                                const CFGBlock *dstBlock);
+
+  BVPair &getValueVectors(const CFGBlock *block, bool shouldLazyCreate);
+
+  void mergeIntoScratch(ValueVector const &source, bool isFirst);
+  bool updateValueVectorWithScratch(const CFGBlock *block);
+  bool updateValueVectors(const CFGBlock *block, const BVPair &newVals);
+  
+  bool hasNoDeclarations() const {
+    return declToIndex.size() == 0;
+  }
+
+  void resetScratch();
+  ValueVector &getScratch() { return scratch; }
+  
+  ValueVector::reference operator[](const VarDecl *vd);
+};  
+} // end anonymous namespace
+
+CFGBlockValues::CFGBlockValues(const CFG &c) : cfg(c), vals(0) {
+  unsigned n = cfg.getNumBlockIDs();
+  if (!n)
+    return;
+  vals = new std::pair<ValueVector*, ValueVector*>[n];
+  memset((void*)vals, 0, sizeof(*vals) * n);
+}
+
+CFGBlockValues::~CFGBlockValues() {
+  unsigned n = cfg.getNumBlockIDs();
+  if (n == 0)
+    return;
+  for (unsigned i = 0; i < n; ++i) {
+    delete vals[i].first;
+    delete vals[i].second;
+  }
+  delete [] vals;
+}
+
+void CFGBlockValues::computeSetOfDeclarations(const DeclContext &dc) {
+  declToIndex.computeMap(dc);
+  scratch.resize(declToIndex.size());
+}
+
+ValueVector &CFGBlockValues::lazyCreate(ValueVector *&bv) {
+  if (!bv)
+    bv = new ValueVector(declToIndex.size());
+  return *bv;
+}
+
+/// This function pattern matches for a '&&' or '||' that appears at
+/// the beginning of a CFGBlock that also (1) has a terminator and 
+/// (2) has no other elements.  If such an expression is found, it is returned.
+static const BinaryOperator *getLogicalOperatorInChain(const CFGBlock *block) {
+  if (block->empty())
+    return 0;
+
+  CFGElement front = block->front();
+  const CFGStmt *cstmt = front.getAs<CFGStmt>();
+  if (!cstmt)
+    return 0;
+
+  const BinaryOperator *b = dyn_cast_or_null<BinaryOperator>(cstmt->getStmt());
+  
+  if (!b || !b->isLogicalOp())
+    return 0;
+  
+  if (block->pred_size() == 2) {
+    if (block->getTerminatorCondition() == b) {
+      if (block->succ_size() == 2)
+      return b;
+    }
+    else if (block->size() == 1)
+      return b;
+  }
+
+  return 0;
+}
+
+ValueVector &CFGBlockValues::getValueVector(const CFGBlock *block,
+                                            const CFGBlock *dstBlock) {
+  unsigned idx = block->getBlockID();
+  if (dstBlock && getLogicalOperatorInChain(block)) {
+    if (*block->succ_begin() == dstBlock)
+      return lazyCreate(vals[idx].first);
+    assert(*(block->succ_begin()+1) == dstBlock);
+    return lazyCreate(vals[idx].second);
+  }
+
+  assert(vals[idx].second == 0);
+  return lazyCreate(vals[idx].first);
+}
+
+BVPair &CFGBlockValues::getValueVectors(const clang::CFGBlock *block,
+                                        bool shouldLazyCreate) {
+  unsigned idx = block->getBlockID();
+  lazyCreate(vals[idx].first);
+  if (shouldLazyCreate)
+    lazyCreate(vals[idx].second);
+  return vals[idx];
+}
+
+#if 0
+static void printVector(const CFGBlock *block, ValueVector &bv,
+                        unsigned num) {
+  
+  llvm::errs() << block->getBlockID() << " :";
+  for (unsigned i = 0; i < bv.size(); ++i) {
+    llvm::errs() << ' ' << bv[i];
+  }
+  llvm::errs() << " : " << num << '\n';
+}
+
+static void printVector(const char *name, ValueVector const &bv) {
+  llvm::errs() << name << " : ";
+  for (unsigned i = 0; i < bv.size(); ++i) {
+    llvm::errs() << ' ' << bv[i];
+  }
+  llvm::errs() << "\n";
+}
+#endif
+
+void CFGBlockValues::mergeIntoScratch(ValueVector const &source,
+                                      bool isFirst) {
+  if (isFirst)
+    scratch = source;
+  else
+    scratch |= source;
+}
+
+bool CFGBlockValues::updateValueVectorWithScratch(const CFGBlock *block) {
+  ValueVector &dst = getValueVector(block, 0);
+  bool changed = (dst != scratch);
+  if (changed)
+    dst = scratch;
+#if 0
+  printVector(block, scratch, 0);
+#endif
+  return changed;
+}
+
+bool CFGBlockValues::updateValueVectors(const CFGBlock *block,
+                                      const BVPair &newVals) {
+  BVPair &vals = getValueVectors(block, true);
+  bool changed = *newVals.first != *vals.first ||
+                 *newVals.second != *vals.second;
+  *vals.first = *newVals.first;
+  *vals.second = *newVals.second;
+#if 0
+  printVector(block, *vals.first, 1);
+  printVector(block, *vals.second, 2);
+#endif
+  return changed;
+}
+
+void CFGBlockValues::resetScratch() {
+  scratch.reset();
+}
+
+ValueVector::reference CFGBlockValues::operator[](const VarDecl *vd) {
+  const llvm::Optional<unsigned> &idx = declToIndex.getValueIndex(vd);
+  assert(idx.hasValue());
+  return scratch[idx.getValue()];
+}
+
+//------------------------------------------------------------------------====//
+// Worklist: worklist for dataflow analysis.
+//====------------------------------------------------------------------------//
+
+namespace {
+class DataflowWorklist {
+  SmallVector<const CFGBlock *, 20> worklist;
+  llvm::BitVector enqueuedBlocks;
+public:
+  DataflowWorklist(const CFG &cfg) : enqueuedBlocks(cfg.getNumBlockIDs()) {}
+  
+  void enqueueSuccessors(const CFGBlock *block);
+  const CFGBlock *dequeue();
+};
+}
+
+void DataflowWorklist::enqueueSuccessors(const clang::CFGBlock *block) {
+  unsigned OldWorklistSize = worklist.size();
+  for (CFGBlock::const_succ_iterator I = block->succ_begin(),
+       E = block->succ_end(); I != E; ++I) {
+    const CFGBlock *Successor = *I;
+    if (!Successor || enqueuedBlocks[Successor->getBlockID()])
+      continue;
+    worklist.push_back(Successor);
+    enqueuedBlocks[Successor->getBlockID()] = true;
+  }
+  if (OldWorklistSize == 0 || OldWorklistSize == worklist.size())
+    return;
+
+  // Rotate the newly added blocks to the start of the worklist so that it forms
+  // a proper queue when we pop off the end of the worklist.
+  std::rotate(worklist.begin(), worklist.begin() + OldWorklistSize,
+              worklist.end());
+}
+
+const CFGBlock *DataflowWorklist::dequeue() {
+  if (worklist.empty())
+    return 0;
+  const CFGBlock *b = worklist.back();
+  worklist.pop_back();
+  enqueuedBlocks[b->getBlockID()] = false;
+  return b;
+}
+
+//------------------------------------------------------------------------====//
+// Transfer function for uninitialized values analysis.
+//====------------------------------------------------------------------------//
+
+namespace {
+class FindVarResult {
+  const VarDecl *vd;
+  const DeclRefExpr *dr;
+public:
+  FindVarResult(VarDecl *vd, DeclRefExpr *dr) : vd(vd), dr(dr) {}
+  
+  const DeclRefExpr *getDeclRefExpr() const { return dr; }
+  const VarDecl *getDecl() const { return vd; }
+};
+  
+class TransferFunctions : public StmtVisitor<TransferFunctions> {
+  CFGBlockValues &vals;
+  const CFG &cfg;
+  AnalysisDeclContext &ac;
+  UninitVariablesHandler *handler;
+  
+  /// The last DeclRefExpr seen when analyzing a block.  Used to
+  /// cheat when detecting cases when the address of a variable is taken.
+  DeclRefExpr *lastDR;
+  
+  /// The last lvalue-to-rvalue conversion of a variable whose value
+  /// was uninitialized.  Normally this results in a warning, but it is
+  /// possible to either silence the warning in some cases, or we
+  /// propagate the uninitialized value.
+  CastExpr *lastLoad;
+  
+  /// For some expressions, we want to ignore any post-processing after
+  /// visitation.
+  bool skipProcessUses;
+  
+public:
+  TransferFunctions(CFGBlockValues &vals, const CFG &cfg,
+                    AnalysisDeclContext &ac,
+                    UninitVariablesHandler *handler)
+    : vals(vals), cfg(cfg), ac(ac), handler(handler),
+      lastDR(0), lastLoad(0),
+      skipProcessUses(false) {}
+  
+  void reportUninit(const DeclRefExpr *ex, const VarDecl *vd,
+                    bool isAlwaysUninit);
+
+  void VisitBlockExpr(BlockExpr *be);
+  void VisitDeclStmt(DeclStmt *ds);
+  void VisitDeclRefExpr(DeclRefExpr *dr);
+  void VisitUnaryOperator(UnaryOperator *uo);
+  void VisitBinaryOperator(BinaryOperator *bo);
+  void VisitCastExpr(CastExpr *ce);
+  void VisitObjCForCollectionStmt(ObjCForCollectionStmt *fs);
+  void Visit(Stmt *s);
+  
+  bool isTrackedVar(const VarDecl *vd) {
+    return ::isTrackedVar(vd, cast<DeclContext>(ac.getDecl()));
+  }
+  
+  FindVarResult findBlockVarDecl(Expr *ex);
+  
+  void ProcessUses(Stmt *s = 0);
+};
+}
+
+static const Expr *stripCasts(ASTContext &C, const Expr *Ex) {
+  while (Ex) {
+    Ex = Ex->IgnoreParenNoopCasts(C);
+    if (const CastExpr *CE = dyn_cast<CastExpr>(Ex)) {
+      if (CE->getCastKind() == CK_LValueBitCast) {
+        Ex = CE->getSubExpr();
+        continue;
+      }
+    }
+    break;
+  }
+  return Ex;
+}
+
+void TransferFunctions::reportUninit(const DeclRefExpr *ex,
+                                     const VarDecl *vd, bool isAlwaysUnit) {
+  if (handler) handler->handleUseOfUninitVariable(ex, vd, isAlwaysUnit);
+}
+
+FindVarResult TransferFunctions::findBlockVarDecl(Expr *ex) {
+  if (DeclRefExpr *dr = dyn_cast<DeclRefExpr>(ex->IgnoreParenCasts()))
+    if (VarDecl *vd = dyn_cast<VarDecl>(dr->getDecl()))
+      if (isTrackedVar(vd))
+        return FindVarResult(vd, dr);  
+  return FindVarResult(0, 0);
+}
+
+void TransferFunctions::VisitObjCForCollectionStmt(ObjCForCollectionStmt *fs) {
+  // This represents an initialization of the 'element' value.
+  Stmt *element = fs->getElement();
+  const VarDecl *vd = 0;
+  
+  if (DeclStmt *ds = dyn_cast<DeclStmt>(element)) {
+    vd = cast<VarDecl>(ds->getSingleDecl());
+    if (!isTrackedVar(vd))
+      vd = 0;
+  } else {
+    // Initialize the value of the reference variable.
+    const FindVarResult &res = findBlockVarDecl(cast<Expr>(element));
+    vd = res.getDecl();
+  }
+  
+  if (vd)
+    vals[vd] = Initialized;
+}
+
+void TransferFunctions::VisitBlockExpr(BlockExpr *be) {
+  const BlockDecl *bd = be->getBlockDecl();
+  for (BlockDecl::capture_const_iterator i = bd->capture_begin(),
+        e = bd->capture_end() ; i != e; ++i) {
+    const VarDecl *vd = i->getVariable();
+    if (!isTrackedVar(vd))
+      continue;
+    if (i->isByRef()) {
+      vals[vd] = Initialized;
+      continue;
+    }
+    Value v = vals[vd];
+    if (handler && isUninitialized(v))
+      handler->handleUseOfUninitVariable(be, vd, isAlwaysUninit(v));
+  }
+}
+
+void TransferFunctions::VisitDeclRefExpr(DeclRefExpr *dr) {
+  // Record the last DeclRefExpr seen.  This is an lvalue computation.
+  // We use this value to later detect if a variable "escapes" the analysis.
+  if (const VarDecl *vd = dyn_cast<VarDecl>(dr->getDecl()))
+    if (isTrackedVar(vd)) {
+      ProcessUses();
+      lastDR = dr;
+    }
+}
+
+void TransferFunctions::VisitDeclStmt(DeclStmt *ds) {
+  for (DeclStmt::decl_iterator DI = ds->decl_begin(), DE = ds->decl_end();
+       DI != DE; ++DI) {
+    if (VarDecl *vd = dyn_cast<VarDecl>(*DI)) {
+      if (isTrackedVar(vd)) {
+        if (Expr *init = vd->getInit()) {
+          // If the initializer consists solely of a reference to itself, we
+          // explicitly mark the variable as uninitialized. This allows code
+          // like the following:
+          //
+          //   int x = x;
+          //
+          // to deliberately leave a variable uninitialized. Different analysis
+          // clients can detect this pattern and adjust their reporting
+          // appropriately, but we need to continue to analyze subsequent uses
+          // of the variable.
+          if (init == lastLoad) {
+            const DeclRefExpr *DR
+              = cast<DeclRefExpr>(stripCasts(ac.getASTContext(),
+                                             lastLoad->getSubExpr()));
+            if (DR->getDecl() == vd) {
+              // int x = x;
+              // Propagate uninitialized value, but don't immediately report
+              // a problem.
+              vals[vd] = Uninitialized;
+              lastLoad = 0;
+              lastDR = 0;
+              if (handler)
+                handler->handleSelfInit(vd);
+              return;
+            }
+          }
+
+          // All other cases: treat the new variable as initialized.
+          // This is a minor optimization to reduce the propagation
+          // of the analysis, since we will have already reported
+          // the use of the uninitialized value (which visiting the
+          // initializer).
+          vals[vd] = Initialized;
+        }
+      }
+    }
+  }
+}
+
+void TransferFunctions::VisitBinaryOperator(clang::BinaryOperator *bo) {
+  if (bo->isAssignmentOp()) {
+    const FindVarResult &res = findBlockVarDecl(bo->getLHS());
+    if (const VarDecl *vd = res.getDecl()) {
+      ValueVector::reference val = vals[vd];
+      if (isUninitialized(val)) {
+        if (bo->getOpcode() != BO_Assign)
+          reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
+        else
+          val = Initialized;
+      }
+    }
+  }
+}
+
+void TransferFunctions::VisitUnaryOperator(clang::UnaryOperator *uo) {
+  switch (uo->getOpcode()) {
+    case clang::UO_PostDec:
+    case clang::UO_PostInc:
+    case clang::UO_PreDec:
+    case clang::UO_PreInc: {
+      const FindVarResult &res = findBlockVarDecl(uo->getSubExpr());
+      if (const VarDecl *vd = res.getDecl()) {
+        assert(res.getDeclRefExpr() == lastDR);
+        // We null out lastDR to indicate we have fully processed it
+        // and we don't want the auto-value setting in Visit().
+        lastDR = 0;
+
+        ValueVector::reference val = vals[vd];
+        if (isUninitialized(val))
+          reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
+      }
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+void TransferFunctions::VisitCastExpr(clang::CastExpr *ce) {
+  if (ce->getCastKind() == CK_LValueToRValue) {
+    const FindVarResult &res = findBlockVarDecl(ce->getSubExpr());
+    if (res.getDecl()) {
+      assert(res.getDeclRefExpr() == lastDR);
+      lastLoad = ce;
+    }
+  }
+  else if (ce->getCastKind() == CK_NoOp ||
+           ce->getCastKind() == CK_LValueBitCast) {
+    skipProcessUses = true;
+  }
+  else if (CStyleCastExpr *cse = dyn_cast<CStyleCastExpr>(ce)) {
+    if (cse->getType()->isVoidType()) {
+      // e.g. (void) x;
+      if (lastLoad == cse->getSubExpr()) {
+        // Squelch any detected load of an uninitialized value if
+        // we cast it to void.
+        lastLoad = 0;
+        lastDR = 0;
+      }
+    }
+  }
+}
+
+void TransferFunctions::Visit(clang::Stmt *s) {
+  skipProcessUses = false;
+  StmtVisitor<TransferFunctions>::Visit(s);
+  if (!skipProcessUses)
+    ProcessUses(s);
+}
+
+void TransferFunctions::ProcessUses(Stmt *s) {
+  // This method is typically called after visiting a CFGElement statement
+  // in the CFG.  We delay processing of reporting many loads of uninitialized
+  // values until here.
+  if (lastLoad) {
+    // If we just visited the lvalue-to-rvalue cast, there is nothing
+    // left to do.
+    if (lastLoad == s)
+      return;
+
+    const DeclRefExpr *DR =
+      cast<DeclRefExpr>(stripCasts(ac.getASTContext(),
+                                   lastLoad->getSubExpr()));
+    const VarDecl *VD = cast<VarDecl>(DR->getDecl());
+
+    // If we reach here, we may have seen a load of an uninitialized value
+    // and it hasn't been casted to void or otherwise handled.  In this
+    // situation, report the incident.
+    if (isUninitialized(vals[VD]))
+      reportUninit(DR, VD, isAlwaysUninit(vals[VD]));
+
+    lastLoad = 0;
+
+    if (DR == lastDR) {
+      lastDR = 0;
+      return;
+    }
+  }
+
+  // Any other uses of 'lastDR' involve taking an lvalue of variable.
+  // In this case, it "escapes" the analysis.
+  if (lastDR && lastDR != s) {
+    vals[cast<VarDecl>(lastDR->getDecl())] = Initialized;
+    lastDR = 0;
+  }
+}
+
+//------------------------------------------------------------------------====//
+// High-level "driver" logic for uninitialized values analysis.
+//====------------------------------------------------------------------------//
+
+static bool runOnBlock(const CFGBlock *block, const CFG &cfg,
+                       AnalysisDeclContext &ac, CFGBlockValues &vals,
+                       llvm::BitVector &wasAnalyzed,
+                       UninitVariablesHandler *handler = 0) {
+  
+  wasAnalyzed[block->getBlockID()] = true;
+  
+  if (const BinaryOperator *b = getLogicalOperatorInChain(block)) {
+    CFGBlock::const_pred_iterator itr = block->pred_begin();
+    BVPair vA = vals.getValueVectors(*itr, false);
+    ++itr;
+    BVPair vB = vals.getValueVectors(*itr, false);
+
+    BVPair valsAB;
+    
+    if (b->getOpcode() == BO_LAnd) {
+      // Merge the 'F' bits from the first and second.
+      vals.mergeIntoScratch(*(vA.second ? vA.second : vA.first), true);
+      vals.mergeIntoScratch(*(vB.second ? vB.second : vB.first), false);
+      valsAB.first = vA.first;
+      valsAB.second = &vals.getScratch();
+    } else {
+      // Merge the 'T' bits from the first and second.
+      assert(b->getOpcode() == BO_LOr);
+      vals.mergeIntoScratch(*vA.first, true);
+      vals.mergeIntoScratch(*vB.first, false);
+      valsAB.first = &vals.getScratch();
+      valsAB.second = vA.second ? vA.second : vA.first;
+    }
+    return vals.updateValueVectors(block, valsAB);
+  }
+
+  // Default behavior: merge in values of predecessor blocks.
+  vals.resetScratch();
+  bool isFirst = true;
+  for (CFGBlock::const_pred_iterator I = block->pred_begin(),
+       E = block->pred_end(); I != E; ++I) {
+    const CFGBlock *pred = *I;
+    if (wasAnalyzed[pred->getBlockID()]) {
+      vals.mergeIntoScratch(vals.getValueVector(pred, block), isFirst);
+      isFirst = false;
+    }
+  }
+  // Apply the transfer function.
+  TransferFunctions tf(vals, cfg, ac, handler);
+  for (CFGBlock::const_iterator I = block->begin(), E = block->end(); 
+       I != E; ++I) {
+    if (const CFGStmt *cs = dyn_cast<CFGStmt>(&*I)) {
+      tf.Visit(const_cast<Stmt*>(cs->getStmt()));
+    }
+  }
+  tf.ProcessUses();
+  return vals.updateValueVectorWithScratch(block);
+}
+
+void clang::runUninitializedVariablesAnalysis(
+    const DeclContext &dc,
+    const CFG &cfg,
+    AnalysisDeclContext &ac,
+    UninitVariablesHandler &handler,
+    UninitVariablesAnalysisStats &stats) {
+  CFGBlockValues vals(cfg);
+  vals.computeSetOfDeclarations(dc);
+  if (vals.hasNoDeclarations())
+    return;
+
+  stats.NumVariablesAnalyzed = vals.getNumEntries();
+
+  // Mark all variables uninitialized at the entry.
+  const CFGBlock &entry = cfg.getEntry();
+  for (CFGBlock::const_succ_iterator i = entry.succ_begin(), 
+        e = entry.succ_end(); i != e; ++i) {
+    if (const CFGBlock *succ = *i) {
+      ValueVector &vec = vals.getValueVector(&entry, succ);
+      const unsigned n = vals.getNumEntries();
+      for (unsigned j = 0; j < n ; ++j) {
+        vec[j] = Uninitialized;
+      }
+    }
+  }
+
+  // Proceed with the workist.
+  DataflowWorklist worklist(cfg);
+  llvm::BitVector previouslyVisited(cfg.getNumBlockIDs());
+  worklist.enqueueSuccessors(&cfg.getEntry());
+  llvm::BitVector wasAnalyzed(cfg.getNumBlockIDs(), false);
+  wasAnalyzed[cfg.getEntry().getBlockID()] = true;
+
+  while (const CFGBlock *block = worklist.dequeue()) {
+    // Did the block change?
+    bool changed = runOnBlock(block, cfg, ac, vals, wasAnalyzed);
+    ++stats.NumBlockVisits;
+    if (changed || !previouslyVisited[block->getBlockID()])
+      worklist.enqueueSuccessors(block);    
+    previouslyVisited[block->getBlockID()] = true;
+  }
+  
+  // Run through the blocks one more time, and report uninitialized variabes.
+  for (CFG::const_iterator BI = cfg.begin(), BE = cfg.end(); BI != BE; ++BI) {
+    const CFGBlock *block = *BI;
+    if (wasAnalyzed[block->getBlockID()]) {
+      runOnBlock(block, cfg, ac, vals, wasAnalyzed, &handler);
+      ++stats.NumBlockVisits;
+    }
+  }
+}
+
+UninitVariablesHandler::~UninitVariablesHandler() {}