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

1 files changed, 295 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/Environment.cpp b/clang/lib/StaticAnalyzer/Core/Environment.cpp
new file mode 100644
index 0000000..b5ea3db
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Core/Environment.cpp
@@ -0,0 +1,295 @@
+//== Environment.cpp - Map from Stmt* to Locations/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 defined the Environment and EnvironmentManager classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+
+using namespace clang;
+using namespace ento;
+
+SVal Environment::lookupExpr(const EnvironmentEntry &E) const {
+  const SVal* X = ExprBindings.lookup(E);
+  if (X) {
+    SVal V = *X;
+    return V;
+  }
+  return UnknownVal();
+}
+
+SVal Environment::getSVal(const EnvironmentEntry &Entry,
+                          SValBuilder& svalBuilder,
+                          bool useOnlyDirectBindings) const {
+
+  if (useOnlyDirectBindings) {
+    // This branch is rarely taken, but can be exercised by
+    // checkers that explicitly bind values to arbitrary
+    // expressions.  It is crucial that we do not ignore any
+    // expression here, and do a direct lookup.
+    return lookupExpr(Entry);
+  }
+
+  const Stmt *E = Entry.getStmt();
+  const LocationContext *LCtx = Entry.getLocationContext();
+  
+  for (;;) {
+    if (const Expr *Ex = dyn_cast<Expr>(E))
+      E = Ex->IgnoreParens();
+
+    switch (E->getStmtClass()) {
+      case Stmt::AddrLabelExprClass:
+        return svalBuilder.makeLoc(cast<AddrLabelExpr>(E));
+      case Stmt::OpaqueValueExprClass: {
+        const OpaqueValueExpr *ope = cast<OpaqueValueExpr>(E);
+        E = ope->getSourceExpr();
+        continue;        
+      }        
+      case Stmt::ParenExprClass:
+      case Stmt::GenericSelectionExprClass:
+        llvm_unreachable("ParenExprs and GenericSelectionExprs should "
+                         "have been handled by IgnoreParens()");
+      case Stmt::CharacterLiteralClass: {
+        const CharacterLiteral* C = cast<CharacterLiteral>(E);
+        return svalBuilder.makeIntVal(C->getValue(), C->getType());
+      }
+      case Stmt::CXXBoolLiteralExprClass: {
+        const SVal *X = ExprBindings.lookup(EnvironmentEntry(E, LCtx));
+        if (X) 
+          return *X;
+        else 
+          return svalBuilder.makeBoolVal(cast<CXXBoolLiteralExpr>(E));
+      }
+      case Stmt::IntegerLiteralClass: {
+        // In C++, this expression may have been bound to a temporary object.
+        SVal const *X = ExprBindings.lookup(EnvironmentEntry(E, LCtx));
+        if (X)
+          return *X;
+        else
+          return svalBuilder.makeIntVal(cast<IntegerLiteral>(E));
+      }
+      case Stmt::ObjCBoolLiteralExprClass:
+        return svalBuilder.makeBoolVal(cast<ObjCBoolLiteralExpr>(E));
+
+      // For special C0xx nullptr case, make a null pointer SVal.
+      case Stmt::CXXNullPtrLiteralExprClass:
+        return svalBuilder.makeNull();
+      case Stmt::ExprWithCleanupsClass:
+        E = cast<ExprWithCleanups>(E)->getSubExpr();
+        continue;
+      case Stmt::CXXBindTemporaryExprClass:
+        E = cast<CXXBindTemporaryExpr>(E)->getSubExpr();
+        continue;
+      case Stmt::ObjCPropertyRefExprClass:
+        return loc::ObjCPropRef(cast<ObjCPropertyRefExpr>(E));
+      case Stmt::ObjCStringLiteralClass: {
+        MemRegionManager &MRMgr = svalBuilder.getRegionManager();
+        const ObjCStringLiteral *SL = cast<ObjCStringLiteral>(E);
+        return svalBuilder.makeLoc(MRMgr.getObjCStringRegion(SL));
+      }
+      case Stmt::StringLiteralClass: {
+        MemRegionManager &MRMgr = svalBuilder.getRegionManager();
+        const StringLiteral *SL = cast<StringLiteral>(E);
+        return svalBuilder.makeLoc(MRMgr.getStringRegion(SL));
+      }
+      case Stmt::ReturnStmtClass: {
+        const ReturnStmt *RS = cast<ReturnStmt>(E);
+        if (const Expr *RE = RS->getRetValue()) {
+          E = RE;
+          continue;
+        }
+        return UndefinedVal();        
+      }
+        
+      // Handle all other Stmt* using a lookup.
+      default:
+        break;
+    };
+    break;
+  }
+  return lookupExpr(EnvironmentEntry(E, LCtx));
+}
+
+Environment EnvironmentManager::bindExpr(Environment Env,
+                                         const EnvironmentEntry &E,
+                                         SVal V,
+                                         bool Invalidate) {
+  if (V.isUnknown()) {
+    if (Invalidate)
+      return Environment(F.remove(Env.ExprBindings, E));
+    else
+      return Env;
+  }
+  return Environment(F.add(Env.ExprBindings, E, V));
+}
+
+static inline EnvironmentEntry MakeLocation(const EnvironmentEntry &E) {
+  const Stmt *S = E.getStmt();
+  S = (const Stmt*) (((uintptr_t) S) | 0x1);
+  return EnvironmentEntry(S, E.getLocationContext());
+}
+
+Environment EnvironmentManager::bindExprAndLocation(Environment Env,
+                                                    const EnvironmentEntry &E,
+                                                    SVal location, SVal V) {
+  return Environment(F.add(F.add(Env.ExprBindings, MakeLocation(E), location),
+                           E, V));
+}
+
+namespace {
+class MarkLiveCallback : public SymbolVisitor {
+  SymbolReaper &SymReaper;
+public:
+  MarkLiveCallback(SymbolReaper &symreaper) : SymReaper(symreaper) {}
+  bool VisitSymbol(SymbolRef sym) {
+    SymReaper.markLive(sym);
+    return true;
+  }
+  bool VisitMemRegion(const MemRegion *R) {
+    SymReaper.markLive(R);
+    return true;
+  }
+};
+} // end anonymous namespace
+
+// In addition to mapping from EnvironmentEntry - > SVals in the Environment,
+// we also maintain a mapping from EnvironmentEntry -> SVals (locations)
+// that were used during a load and store.
+static inline bool IsLocation(const EnvironmentEntry &E) {
+  const Stmt *S = E.getStmt();
+  return (bool) (((uintptr_t) S) & 0x1);
+}
+
+// removeDeadBindings:
+//  - Remove subexpression bindings.
+//  - Remove dead block expression bindings.
+//  - Keep live block expression bindings:
+//   - Mark their reachable symbols live in SymbolReaper,
+//     see ScanReachableSymbols.
+//   - Mark the region in DRoots if the binding is a loc::MemRegionVal.
+Environment
+EnvironmentManager::removeDeadBindings(Environment Env,
+                                       SymbolReaper &SymReaper,
+                                       ProgramStateRef ST) {
+
+  // We construct a new Environment object entirely, as this is cheaper than
+  // individually removing all the subexpression bindings (which will greatly
+  // outnumber block-level expression bindings).
+  Environment NewEnv = getInitialEnvironment();
+  
+  SmallVector<std::pair<EnvironmentEntry, SVal>, 10> deferredLocations;
+
+  MarkLiveCallback CB(SymReaper);
+  ScanReachableSymbols RSScaner(ST, CB);
+
+  llvm::ImmutableMapRef<EnvironmentEntry,SVal>
+    EBMapRef(NewEnv.ExprBindings.getRootWithoutRetain(),
+             F.getTreeFactory());
+
+  // Iterate over the block-expr bindings.
+  for (Environment::iterator I = Env.begin(), E = Env.end();
+       I != E; ++I) {
+
+    const EnvironmentEntry &BlkExpr = I.getKey();
+    // For recorded locations (used when evaluating loads and stores), we
+    // consider them live only when their associated normal expression is
+    // also live.
+    // NOTE: This assumes that loads/stores that evaluated to UnknownVal
+    // still have an entry in the map.
+    if (IsLocation(BlkExpr)) {
+      deferredLocations.push_back(std::make_pair(BlkExpr, I.getData()));
+      continue;
+    }
+    const SVal &X = I.getData();
+
+    if (SymReaper.isLive(BlkExpr.getStmt(), BlkExpr.getLocationContext())) {
+      // Copy the binding to the new map.
+      EBMapRef = EBMapRef.add(BlkExpr, X);
+
+      // If the block expr's value is a memory region, then mark that region.
+      if (isa<loc::MemRegionVal>(X)) {
+        const MemRegion *R = cast<loc::MemRegionVal>(X).getRegion();
+        SymReaper.markLive(R);
+      }
+
+      // Mark all symbols in the block expr's value live.
+      RSScaner.scan(X);
+      continue;
+    }
+
+    // Otherwise the expression is dead with a couple exceptions.
+    // Do not misclean LogicalExpr or ConditionalOperator.  It is dead at the
+    // beginning of itself, but we need its UndefinedVal to determine its
+    // SVal.
+    if (X.isUndef() && cast<UndefinedVal>(X).getData())
+      EBMapRef = EBMapRef.add(BlkExpr, X);
+  }
+  
+  // Go through he deferred locations and add them to the new environment if
+  // the correspond Stmt* is in the map as well.
+  for (SmallVectorImpl<std::pair<EnvironmentEntry, SVal> >::iterator
+      I = deferredLocations.begin(), E = deferredLocations.end(); I != E; ++I) {
+    const EnvironmentEntry &En = I->first;
+    const Stmt *S = (Stmt*) (((uintptr_t) En.getStmt()) & (uintptr_t) ~0x1);
+    if (EBMapRef.lookup(EnvironmentEntry(S, En.getLocationContext())))
+      EBMapRef = EBMapRef.add(En, I->second);
+  }
+
+  NewEnv.ExprBindings = EBMapRef.asImmutableMap();
+  return NewEnv;
+}
+
+void Environment::print(raw_ostream &Out, const char *NL,
+                        const char *Sep) const {
+  printAux(Out, false, NL, Sep);
+  printAux(Out, true, NL, Sep);
+}
+  
+void Environment::printAux(raw_ostream &Out, bool printLocations,
+                           const char *NL,
+                           const char *Sep) const{
+
+  bool isFirst = true;
+
+  for (Environment::iterator I = begin(), E = end(); I != E; ++I) {
+    const EnvironmentEntry &En = I.getKey();
+    if (IsLocation(En)) {
+      if (!printLocations)
+        continue;
+    }
+    else {
+      if (printLocations)
+        continue;
+    }
+    
+    if (isFirst) {
+      Out << NL << NL
+          << (printLocations ? "Load/Store locations:" : "Expressions:")
+          << NL;      
+      isFirst = false;
+    } else {
+      Out << NL;
+    }
+    
+    const Stmt *S = En.getStmt();
+    if (printLocations) {
+      S = (Stmt*) (((uintptr_t) S) & ((uintptr_t) ~0x1));
+    }
+    
+    Out << " (" << (void*) En.getLocationContext() << ',' << (void*) S << ") ";
+    LangOptions LO; // FIXME.
+    S->printPretty(Out, 0, PrintingPolicy(LO));
+    Out << " : " << I.getData();
+  }
+}