Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 1564 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
new file mode 100644
index 0000000..6447779
--- /dev/null
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -0,0 +1,1564 @@
+//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code to emit Decl nodes as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGDebugInfo.h"
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "CGOpenCLRuntime.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/CharUnits.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Frontend/CodeGenOptions.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Type.h"
+using namespace clang;
+using namespace CodeGen;
+
+
+void CodeGenFunction::EmitDecl(const Decl &D) {
+  switch (D.getKind()) {
+  case Decl::TranslationUnit:
+  case Decl::Namespace:
+  case Decl::UnresolvedUsingTypename:
+  case Decl::ClassTemplateSpecialization:
+  case Decl::ClassTemplatePartialSpecialization:
+  case Decl::TemplateTypeParm:
+  case Decl::UnresolvedUsingValue:
+  case Decl::NonTypeTemplateParm:
+  case Decl::CXXMethod:
+  case Decl::CXXConstructor:
+  case Decl::CXXDestructor:
+  case Decl::CXXConversion:
+  case Decl::Field:
+  case Decl::IndirectField:
+  case Decl::ObjCIvar:
+  case Decl::ObjCAtDefsField:
+  case Decl::ParmVar:
+  case Decl::ImplicitParam:
+  case Decl::ClassTemplate:
+  case Decl::FunctionTemplate:
+  case Decl::TypeAliasTemplate:
+  case Decl::TemplateTemplateParm:
+  case Decl::ObjCMethod:
+  case Decl::ObjCCategory:
+  case Decl::ObjCProtocol:
+  case Decl::ObjCInterface:
+  case Decl::ObjCCategoryImpl:
+  case Decl::ObjCImplementation:
+  case Decl::ObjCProperty:
+  case Decl::ObjCCompatibleAlias:
+  case Decl::AccessSpec:
+  case Decl::LinkageSpec:
+  case Decl::ObjCPropertyImpl:
+  case Decl::FileScopeAsm:
+  case Decl::Friend:
+  case Decl::FriendTemplate:
+  case Decl::Block:
+  case Decl::ClassScopeFunctionSpecialization:
+    llvm_unreachable("Declaration should not be in declstmts!");
+  case Decl::Function:  // void X();
+  case Decl::Record:    // struct/union/class X;
+  case Decl::Enum:      // enum X;
+  case Decl::EnumConstant: // enum ? { X = ? }
+  case Decl::CXXRecord: // struct/union/class X; [C++]
+  case Decl::Using:          // using X; [C++]
+  case Decl::UsingShadow:
+  case Decl::UsingDirective: // using namespace X; [C++]
+  case Decl::NamespaceAlias:
+  case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
+  case Decl::Label:        // __label__ x;
+  case Decl::Import:
+    // None of these decls require codegen support.
+    return;
+
+  case Decl::Var: {
+    const VarDecl &VD = cast<VarDecl>(D);
+    assert(VD.isLocalVarDecl() &&
+           "Should not see file-scope variables inside a function!");
+    return EmitVarDecl(VD);
+  }
+
+  case Decl::Typedef:      // typedef int X;
+  case Decl::TypeAlias: {  // using X = int; [C++0x]
+    const TypedefNameDecl &TD = cast<TypedefNameDecl>(D);
+    QualType Ty = TD.getUnderlyingType();
+
+    if (Ty->isVariablyModifiedType())
+      EmitVariablyModifiedType(Ty);
+  }
+  }
+}
+
+/// EmitVarDecl - This method handles emission of any variable declaration
+/// inside a function, including static vars etc.
+void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
+  switch (D.getStorageClass()) {
+  case SC_None:
+  case SC_Auto:
+  case SC_Register:
+    return EmitAutoVarDecl(D);
+  case SC_Static: {
+    llvm::GlobalValue::LinkageTypes Linkage =
+      llvm::GlobalValue::InternalLinkage;
+
+    // If the function definition has some sort of weak linkage, its
+    // static variables should also be weak so that they get properly
+    // uniqued.  We can't do this in C, though, because there's no
+    // standard way to agree on which variables are the same (i.e.
+    // there's no mangling).
+    if (getContext().getLangOpts().CPlusPlus)
+      if (llvm::GlobalValue::isWeakForLinker(CurFn->getLinkage()))
+        Linkage = CurFn->getLinkage();
+
+    return EmitStaticVarDecl(D, Linkage);
+  }
+  case SC_Extern:
+  case SC_PrivateExtern:
+    // Don't emit it now, allow it to be emitted lazily on its first use.
+    return;
+  case SC_OpenCLWorkGroupLocal:
+    return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D);
+  }
+
+  llvm_unreachable("Unknown storage class");
+}
+
+static std::string GetStaticDeclName(CodeGenFunction &CGF, const VarDecl &D,
+                                     const char *Separator) {
+  CodeGenModule &CGM = CGF.CGM;
+  if (CGF.getContext().getLangOpts().CPlusPlus) {
+    StringRef Name = CGM.getMangledName(&D);
+    return Name.str();
+  }
+
+  std::string ContextName;
+  if (!CGF.CurFuncDecl) {
+    // Better be in a block declared in global scope.
+    const NamedDecl *ND = cast<NamedDecl>(&D);
+    const DeclContext *DC = ND->getDeclContext();
+    if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) {
+      MangleBuffer Name;
+      CGM.getBlockMangledName(GlobalDecl(), Name, BD);
+      ContextName = Name.getString();
+    }
+    else
+      llvm_unreachable("Unknown context for block static var decl");
+  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CGF.CurFuncDecl)) {
+    StringRef Name = CGM.getMangledName(FD);
+    ContextName = Name.str();
+  } else if (isa<ObjCMethodDecl>(CGF.CurFuncDecl))
+    ContextName = CGF.CurFn->getName();
+  else
+    llvm_unreachable("Unknown context for static var decl");
+
+  return ContextName + Separator + D.getNameAsString();
+}
+
+llvm::GlobalVariable *
+CodeGenFunction::CreateStaticVarDecl(const VarDecl &D,
+                                     const char *Separator,
+                                     llvm::GlobalValue::LinkageTypes Linkage) {
+  QualType Ty = D.getType();
+  assert(Ty->isConstantSizeType() && "VLAs can't be static");
+
+  // Use the label if the variable is renamed with the asm-label extension.
+  std::string Name;
+  if (D.hasAttr<AsmLabelAttr>())
+    Name = CGM.getMangledName(&D);
+  else
+    Name = GetStaticDeclName(*this, D, Separator);
+
+  llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
+  llvm::GlobalVariable *GV =
+    new llvm::GlobalVariable(CGM.getModule(), LTy,
+                             Ty.isConstant(getContext()), Linkage,
+                             CGM.EmitNullConstant(D.getType()), Name, 0,
+                             D.isThreadSpecified(),
+                             CGM.getContext().getTargetAddressSpace(Ty));
+  GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
+  if (Linkage != llvm::GlobalValue::InternalLinkage)
+    GV->setVisibility(CurFn->getVisibility());
+  return GV;
+}
+
+/// hasNontrivialDestruction - Determine whether a type's destruction is
+/// non-trivial. If so, and the variable uses static initialization, we must
+/// register its destructor to run on exit.
+static bool hasNontrivialDestruction(QualType T) {
+  CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
+  return RD && !RD->hasTrivialDestructor();
+}
+
+/// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
+/// global variable that has already been created for it.  If the initializer
+/// has a different type than GV does, this may free GV and return a different
+/// one.  Otherwise it just returns GV.
+llvm::GlobalVariable *
+CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
+                                               llvm::GlobalVariable *GV) {
+  llvm::Constant *Init = CGM.EmitConstantInit(D, this);
+
+  // If constant emission failed, then this should be a C++ static
+  // initializer.
+  if (!Init) {
+    if (!getContext().getLangOpts().CPlusPlus)
+      CGM.ErrorUnsupported(D.getInit(), "constant l-value expression");
+    else if (Builder.GetInsertBlock()) {
+      // Since we have a static initializer, this global variable can't
+      // be constant.
+      GV->setConstant(false);
+
+      EmitCXXGuardedInit(D, GV, /*PerformInit*/true);
+    }
+    return GV;
+  }
+
+  // The initializer may differ in type from the global. Rewrite
+  // the global to match the initializer.  (We have to do this
+  // because some types, like unions, can't be completely represented
+  // in the LLVM type system.)
+  if (GV->getType()->getElementType() != Init->getType()) {
+    llvm::GlobalVariable *OldGV = GV;
+
+    GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
+                                  OldGV->isConstant(),
+                                  OldGV->getLinkage(), Init, "",
+                                  /*InsertBefore*/ OldGV,
+                                  D.isThreadSpecified(),
+                           CGM.getContext().getTargetAddressSpace(D.getType()));
+    GV->setVisibility(OldGV->getVisibility());
+
+    // Steal the name of the old global
+    GV->takeName(OldGV);
+
+    // Replace all uses of the old global with the new global
+    llvm::Constant *NewPtrForOldDecl =
+    llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
+    OldGV->replaceAllUsesWith(NewPtrForOldDecl);
+
+    // Erase the old global, since it is no longer used.
+    OldGV->eraseFromParent();
+  }
+
+  GV->setConstant(CGM.isTypeConstant(D.getType(), true));
+  GV->setInitializer(Init);
+
+  if (hasNontrivialDestruction(D.getType())) {
+    // We have a constant initializer, but a nontrivial destructor. We still
+    // need to perform a guarded "initialization" in order to register the
+    // destructor.
+    EmitCXXGuardedInit(D, GV, /*PerformInit*/false);
+  }
+
+  return GV;
+}
+
+void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
+                                      llvm::GlobalValue::LinkageTypes Linkage) {
+  llvm::Value *&DMEntry = LocalDeclMap[&D];
+  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
+
+  // Check to see if we already have a global variable for this
+  // declaration.  This can happen when double-emitting function
+  // bodies, e.g. with complete and base constructors.
+  llvm::Constant *addr =
+    CGM.getStaticLocalDeclAddress(&D);
+
+  llvm::GlobalVariable *var;
+  if (addr) {
+    var = cast<llvm::GlobalVariable>(addr->stripPointerCasts());
+  } else {
+    addr = var = CreateStaticVarDecl(D, ".", Linkage);
+  }
+
+  // Store into LocalDeclMap before generating initializer to handle
+  // circular references.
+  DMEntry = addr;
+  CGM.setStaticLocalDeclAddress(&D, addr);
+
+  // We can't have a VLA here, but we can have a pointer to a VLA,
+  // even though that doesn't really make any sense.
+  // Make sure to evaluate VLA bounds now so that we have them for later.
+  if (D.getType()->isVariablyModifiedType())
+    EmitVariablyModifiedType(D.getType());
+
+  // Save the type in case adding the initializer forces a type change.
+  llvm::Type *expectedType = addr->getType();
+
+  // If this value has an initializer, emit it.
+  if (D.getInit())
+    var = AddInitializerToStaticVarDecl(D, var);
+
+  var->setAlignment(getContext().getDeclAlign(&D).getQuantity());
+
+  if (D.hasAttr<AnnotateAttr>())
+    CGM.AddGlobalAnnotations(&D, var);
+
+  if (const SectionAttr *SA = D.getAttr<SectionAttr>())
+    var->setSection(SA->getName());
+
+  if (D.hasAttr<UsedAttr>())
+    CGM.AddUsedGlobal(var);
+
+  // We may have to cast the constant because of the initializer
+  // mismatch above.
+  //
+  // FIXME: It is really dangerous to store this in the map; if anyone
+  // RAUW's the GV uses of this constant will be invalid.
+  llvm::Constant *castedAddr = llvm::ConstantExpr::getBitCast(var, expectedType);
+  DMEntry = castedAddr;
+  CGM.setStaticLocalDeclAddress(&D, castedAddr);
+
+  // Emit global variable debug descriptor for static vars.
+  CGDebugInfo *DI = getDebugInfo();
+  if (DI) {
+    DI->setLocation(D.getLocation());
+    DI->EmitGlobalVariable(var, &D);
+  }
+}
+
+namespace {
+  struct DestroyObject : EHScopeStack::Cleanup {
+    DestroyObject(llvm::Value *addr, QualType type,
+                  CodeGenFunction::Destroyer *destroyer,
+                  bool useEHCleanupForArray)
+      : addr(addr), type(type), destroyer(destroyer),
+        useEHCleanupForArray(useEHCleanupForArray) {}
+
+    llvm::Value *addr;
+    QualType type;
+    CodeGenFunction::Destroyer *destroyer;
+    bool useEHCleanupForArray;
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      // Don't use an EH cleanup recursively from an EH cleanup.
+      bool useEHCleanupForArray =
+        flags.isForNormalCleanup() && this->useEHCleanupForArray;
+
+      CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
+    }
+  };
+
+  struct DestroyNRVOVariable : EHScopeStack::Cleanup {
+    DestroyNRVOVariable(llvm::Value *addr,
+                        const CXXDestructorDecl *Dtor,
+                        llvm::Value *NRVOFlag)
+      : Dtor(Dtor), NRVOFlag(NRVOFlag), Loc(addr) {}
+
+    const CXXDestructorDecl *Dtor;
+    llvm::Value *NRVOFlag;
+    llvm::Value *Loc;
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      // Along the exceptions path we always execute the dtor.
+      bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
+
+      llvm::BasicBlock *SkipDtorBB = 0;
+      if (NRVO) {
+        // If we exited via NRVO, we skip the destructor call.
+        llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused");
+        SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor");
+        llvm::Value *DidNRVO = CGF.Builder.CreateLoad(NRVOFlag, "nrvo.val");
+        CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB);
+        CGF.EmitBlock(RunDtorBB);
+      }
+
+      CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
+                                /*ForVirtualBase=*/false, Loc);
+
+      if (NRVO) CGF.EmitBlock(SkipDtorBB);
+    }
+  };
+
+  struct CallStackRestore : EHScopeStack::Cleanup {
+    llvm::Value *Stack;
+    CallStackRestore(llvm::Value *Stack) : Stack(Stack) {}
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      llvm::Value *V = CGF.Builder.CreateLoad(Stack);
+      llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
+      CGF.Builder.CreateCall(F, V);
+    }
+  };
+
+  struct ExtendGCLifetime : EHScopeStack::Cleanup {
+    const VarDecl &Var;
+    ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      // Compute the address of the local variable, in case it's a
+      // byref or something.
+      DeclRefExpr DRE(const_cast<VarDecl*>(&Var), false,
+                      Var.getType(), VK_LValue, SourceLocation());
+      llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE));
+      CGF.EmitExtendGCLifetime(value);
+    }
+  };
+
+  struct CallCleanupFunction : EHScopeStack::Cleanup {
+    llvm::Constant *CleanupFn;
+    const CGFunctionInfo &FnInfo;
+    const VarDecl &Var;
+
+    CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
+                        const VarDecl *Var)
+      : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      DeclRefExpr DRE(const_cast<VarDecl*>(&Var), false,
+                      Var.getType(), VK_LValue, SourceLocation());
+      // Compute the address of the local variable, in case it's a byref
+      // or something.
+      llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getAddress();
+
+      // In some cases, the type of the function argument will be different from
+      // the type of the pointer. An example of this is
+      // void f(void* arg);
+      // __attribute__((cleanup(f))) void *g;
+      //
+      // To fix this we insert a bitcast here.
+      QualType ArgTy = FnInfo.arg_begin()->type;
+      llvm::Value *Arg =
+        CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy));
+
+      CallArgList Args;
+      Args.add(RValue::get(Arg),
+               CGF.getContext().getPointerType(Var.getType()));
+      CGF.EmitCall(FnInfo, CleanupFn, ReturnValueSlot(), Args);
+    }
+  };
+}
+
+/// EmitAutoVarWithLifetime - Does the setup required for an automatic
+/// variable with lifetime.
+static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
+                                    llvm::Value *addr,
+                                    Qualifiers::ObjCLifetime lifetime) {
+  switch (lifetime) {
+  case Qualifiers::OCL_None:
+    llvm_unreachable("present but none");
+
+  case Qualifiers::OCL_ExplicitNone:
+    // nothing to do
+    break;
+
+  case Qualifiers::OCL_Strong: {
+    CodeGenFunction::Destroyer *destroyer =
+      (var.hasAttr<ObjCPreciseLifetimeAttr>()
+       ? CodeGenFunction::destroyARCStrongPrecise
+       : CodeGenFunction::destroyARCStrongImprecise);
+
+    CleanupKind cleanupKind = CGF.getARCCleanupKind();
+    CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer,
+                    cleanupKind & EHCleanup);
+    break;
+  }
+  case Qualifiers::OCL_Autoreleasing:
+    // nothing to do
+    break;
+
+  case Qualifiers::OCL_Weak:
+    // __weak objects always get EH cleanups; otherwise, exceptions
+    // could cause really nasty crashes instead of mere leaks.
+    CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(),
+                    CodeGenFunction::destroyARCWeak,
+                    /*useEHCleanup*/ true);
+    break;
+  }
+}
+
+static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
+  if (const Expr *e = dyn_cast<Expr>(s)) {
+    // Skip the most common kinds of expressions that make
+    // hierarchy-walking expensive.
+    s = e = e->IgnoreParenCasts();
+
+    if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e))
+      return (ref->getDecl() == &var);
+  }
+
+  for (Stmt::const_child_range children = s->children(); children; ++children)
+    // children might be null; as in missing decl or conditional of an if-stmt.
+    if ((*children) && isAccessedBy(var, *children))
+      return true;
+
+  return false;
+}
+
+static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
+  if (!decl) return false;
+  if (!isa<VarDecl>(decl)) return false;
+  const VarDecl *var = cast<VarDecl>(decl);
+  return isAccessedBy(*var, e);
+}
+
+static void drillIntoBlockVariable(CodeGenFunction &CGF,
+                                   LValue &lvalue,
+                                   const VarDecl *var) {
+  lvalue.setAddress(CGF.BuildBlockByrefAddress(lvalue.getAddress(), var));
+}
+
+void CodeGenFunction::EmitScalarInit(const Expr *init,
+                                     const ValueDecl *D,
+                                     LValue lvalue,
+                                     bool capturedByInit) {
+  Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
+  if (!lifetime) {
+    llvm::Value *value = EmitScalarExpr(init);
+    if (capturedByInit)
+      drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
+    EmitStoreThroughLValue(RValue::get(value), lvalue, true);
+    return;
+  }
+
+  // If we're emitting a value with lifetime, we have to do the
+  // initialization *before* we leave the cleanup scopes.
+  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(init)) {
+    enterFullExpression(ewc);
+    init = ewc->getSubExpr();
+  }
+  CodeGenFunction::RunCleanupsScope Scope(*this);
+
+  // We have to maintain the illusion that the variable is
+  // zero-initialized.  If the variable might be accessed in its
+  // initializer, zero-initialize before running the initializer, then
+  // actually perform the initialization with an assign.
+  bool accessedByInit = false;
+  if (lifetime != Qualifiers::OCL_ExplicitNone)
+    accessedByInit = (capturedByInit || isAccessedBy(D, init));
+  if (accessedByInit) {
+    LValue tempLV = lvalue;
+    // Drill down to the __block object if necessary.
+    if (capturedByInit) {
+      // We can use a simple GEP for this because it can't have been
+      // moved yet.
+      tempLV.setAddress(Builder.CreateStructGEP(tempLV.getAddress(),
+                                   getByRefValueLLVMField(cast<VarDecl>(D))));
+    }
+
+    llvm::PointerType *ty
+      = cast<llvm::PointerType>(tempLV.getAddress()->getType());
+    ty = cast<llvm::PointerType>(ty->getElementType());
+
+    llvm::Value *zero = llvm::ConstantPointerNull::get(ty);
+
+    // If __weak, we want to use a barrier under certain conditions.
+    if (lifetime == Qualifiers::OCL_Weak)
+      EmitARCInitWeak(tempLV.getAddress(), zero);
+
+    // Otherwise just do a simple store.
+    else
+      EmitStoreOfScalar(zero, tempLV, /* isInitialization */ true);
+  }
+
+  // Emit the initializer.
+  llvm::Value *value = 0;
+
+  switch (lifetime) {
+  case Qualifiers::OCL_None:
+    llvm_unreachable("present but none");
+
+  case Qualifiers::OCL_ExplicitNone:
+    // nothing to do
+    value = EmitScalarExpr(init);
+    break;
+
+  case Qualifiers::OCL_Strong: {
+    value = EmitARCRetainScalarExpr(init);
+    break;
+  }
+
+  case Qualifiers::OCL_Weak: {
+    // No way to optimize a producing initializer into this.  It's not
+    // worth optimizing for, because the value will immediately
+    // disappear in the common case.
+    value = EmitScalarExpr(init);
+
+    if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
+    if (accessedByInit)
+      EmitARCStoreWeak(lvalue.getAddress(), value, /*ignored*/ true);
+    else
+      EmitARCInitWeak(lvalue.getAddress(), value);
+    return;
+  }
+
+  case Qualifiers::OCL_Autoreleasing:
+    value = EmitARCRetainAutoreleaseScalarExpr(init);
+    break;
+  }
+
+  if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
+
+  // If the variable might have been accessed by its initializer, we
+  // might have to initialize with a barrier.  We have to do this for
+  // both __weak and __strong, but __weak got filtered out above.
+  if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
+    llvm::Value *oldValue = EmitLoadOfScalar(lvalue);
+    EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
+    EmitARCRelease(oldValue, /*precise*/ false);
+    return;
+  }
+
+  EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
+}
+
+/// EmitScalarInit - Initialize the given lvalue with the given object.
+void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
+  Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
+  if (!lifetime)
+    return EmitStoreThroughLValue(RValue::get(init), lvalue, true);
+
+  switch (lifetime) {
+  case Qualifiers::OCL_None:
+    llvm_unreachable("present but none");
+
+  case Qualifiers::OCL_ExplicitNone:
+    // nothing to do
+    break;
+
+  case Qualifiers::OCL_Strong:
+    init = EmitARCRetain(lvalue.getType(), init);
+    break;
+
+  case Qualifiers::OCL_Weak:
+    // Initialize and then skip the primitive store.
+    EmitARCInitWeak(lvalue.getAddress(), init);
+    return;
+
+  case Qualifiers::OCL_Autoreleasing:
+    init = EmitARCRetainAutorelease(lvalue.getType(), init);
+    break;
+  }
+
+  EmitStoreOfScalar(init, lvalue, /* isInitialization */ true);
+}
+
+/// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the
+/// non-zero parts of the specified initializer with equal or fewer than
+/// NumStores scalar stores.
+static bool canEmitInitWithFewStoresAfterMemset(llvm::Constant *Init,
+                                                unsigned &NumStores) {
+  // Zero and Undef never requires any extra stores.
+  if (isa<llvm::ConstantAggregateZero>(Init) ||
+      isa<llvm::ConstantPointerNull>(Init) ||
+      isa<llvm::UndefValue>(Init))
+    return true;
+  if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
+      isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
+      isa<llvm::ConstantExpr>(Init))
+    return Init->isNullValue() || NumStores--;
+
+  // See if we can emit each element.
+  if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) {
+    for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
+      llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
+      if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores))
+        return false;
+    }
+    return true;
+  }
+  
+  if (llvm::ConstantDataSequential *CDS =
+        dyn_cast<llvm::ConstantDataSequential>(Init)) {
+    for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
+      llvm::Constant *Elt = CDS->getElementAsConstant(i);
+      if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores))
+        return false;
+    }
+    return true;
+  }
+
+  // Anything else is hard and scary.
+  return false;
+}
+
+/// emitStoresForInitAfterMemset - For inits that
+/// canEmitInitWithFewStoresAfterMemset returned true for, emit the scalar
+/// stores that would be required.
+static void emitStoresForInitAfterMemset(llvm::Constant *Init, llvm::Value *Loc,
+                                         bool isVolatile, CGBuilderTy &Builder) {
+  // Zero doesn't require a store.
+  if (Init->isNullValue() || isa<llvm::UndefValue>(Init))
+    return;
+
+  if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
+      isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
+      isa<llvm::ConstantExpr>(Init)) {
+    Builder.CreateStore(Init, Loc, isVolatile);
+    return;
+  }
+  
+  if (llvm::ConstantDataSequential *CDS = 
+        dyn_cast<llvm::ConstantDataSequential>(Init)) {
+    for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
+      llvm::Constant *Elt = CDS->getElementAsConstant(i);
+      
+      // Get a pointer to the element and emit it.
+      emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i),
+                                   isVolatile, Builder);
+    }
+    return;
+  }
+
+  assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
+         "Unknown value type!");
+
+  for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
+    llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
+    // Get a pointer to the element and emit it.
+    emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i),
+                                 isVolatile, Builder);
+  }
+}
+
+
+/// shouldUseMemSetPlusStoresToInitialize - Decide whether we should use memset
+/// plus some stores to initialize a local variable instead of using a memcpy
+/// from a constant global.  It is beneficial to use memset if the global is all
+/// zeros, or mostly zeros and large.
+static bool shouldUseMemSetPlusStoresToInitialize(llvm::Constant *Init,
+                                                  uint64_t GlobalSize) {
+  // If a global is all zeros, always use a memset.
+  if (isa<llvm::ConstantAggregateZero>(Init)) return true;
+
+
+  // If a non-zero global is <= 32 bytes, always use a memcpy.  If it is large,
+  // do it if it will require 6 or fewer scalar stores.
+  // TODO: Should budget depends on the size?  Avoiding a large global warrants
+  // plopping in more stores.
+  unsigned StoreBudget = 6;
+  uint64_t SizeLimit = 32;
+
+  return GlobalSize > SizeLimit &&
+         canEmitInitWithFewStoresAfterMemset(Init, StoreBudget);
+}
+
+
+/// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
+/// variable declaration with auto, register, or no storage class specifier.
+/// These turn into simple stack objects, or GlobalValues depending on target.
+void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
+  AutoVarEmission emission = EmitAutoVarAlloca(D);
+  EmitAutoVarInit(emission);
+  EmitAutoVarCleanups(emission);
+}
+
+/// EmitAutoVarAlloca - Emit the alloca and debug information for a
+/// local variable.  Does not emit initalization or destruction.
+CodeGenFunction::AutoVarEmission
+CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
+  QualType Ty = D.getType();
+
+  AutoVarEmission emission(D);
+
+  bool isByRef = D.hasAttr<BlocksAttr>();
+  emission.IsByRef = isByRef;
+
+  CharUnits alignment = getContext().getDeclAlign(&D);
+  emission.Alignment = alignment;
+
+  // If the type is variably-modified, emit all the VLA sizes for it.
+  if (Ty->isVariablyModifiedType())
+    EmitVariablyModifiedType(Ty);
+
+  llvm::Value *DeclPtr;
+  if (Ty->isConstantSizeType()) {
+    if (!Target.useGlobalsForAutomaticVariables()) {
+      bool NRVO = getContext().getLangOpts().ElideConstructors &&
+                  D.isNRVOVariable();
+
+      // If this value is a POD array or struct with a statically
+      // determinable constant initializer, there are optimizations we can do.
+      //
+      // TODO: We should constant-evaluate the initializer of any variable,
+      // as long as it is initialized by a constant expression. Currently,
+      // isConstantInitializer produces wrong answers for structs with
+      // reference or bitfield members, and a few other cases, and checking
+      // for POD-ness protects us from some of these.
+      if (D.getInit() &&
+          (Ty->isArrayType() || Ty->isRecordType()) &&
+          (Ty.isPODType(getContext()) ||
+           getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) &&
+          D.getInit()->isConstantInitializer(getContext(), false)) {
+
+        // If the variable's a const type, and it's neither an NRVO
+        // candidate nor a __block variable and has no mutable members,
+        // emit it as a global instead.
+        if (CGM.getCodeGenOpts().MergeAllConstants && !NRVO && !isByRef &&
+            CGM.isTypeConstant(Ty, true)) {
+          EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage);
+
+          emission.Address = 0; // signal this condition to later callbacks
+          assert(emission.wasEmittedAsGlobal());
+          return emission;
+        }
+
+        // Otherwise, tell the initialization code that we're in this case.
+        emission.IsConstantAggregate = true;
+      }
+
+      // A normal fixed sized variable becomes an alloca in the entry block,
+      // unless it's an NRVO variable.
+      llvm::Type *LTy = ConvertTypeForMem(Ty);
+
+      if (NRVO) {
+        // The named return value optimization: allocate this variable in the
+        // return slot, so that we can elide the copy when returning this
+        // variable (C++0x [class.copy]p34).
+        DeclPtr = ReturnValue;
+
+        if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
+          if (!cast<CXXRecordDecl>(RecordTy->getDecl())->hasTrivialDestructor()) {
+            // Create a flag that is used to indicate when the NRVO was applied
+            // to this variable. Set it to zero to indicate that NRVO was not
+            // applied.
+            llvm::Value *Zero = Builder.getFalse();
+            llvm::Value *NRVOFlag = CreateTempAlloca(Zero->getType(), "nrvo");
+            EnsureInsertPoint();
+            Builder.CreateStore(Zero, NRVOFlag);
+
+            // Record the NRVO flag for this variable.
+            NRVOFlags[&D] = NRVOFlag;
+            emission.NRVOFlag = NRVOFlag;
+          }
+        }
+      } else {
+        if (isByRef)
+          LTy = BuildByRefType(&D);
+
+        llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
+        Alloc->setName(D.getName());
+
+        CharUnits allocaAlignment = alignment;
+        if (isByRef)
+          allocaAlignment = std::max(allocaAlignment,
+              getContext().toCharUnitsFromBits(Target.getPointerAlign(0)));
+        Alloc->setAlignment(allocaAlignment.getQuantity());
+        DeclPtr = Alloc;
+      }
+    } else {
+      // Targets that don't support recursion emit locals as globals.
+      const char *Class =
+        D.getStorageClass() == SC_Register ? ".reg." : ".auto.";
+      DeclPtr = CreateStaticVarDecl(D, Class,
+                                    llvm::GlobalValue::InternalLinkage);
+    }
+  } else {
+    EnsureInsertPoint();
+
+    if (!DidCallStackSave) {
+      // Save the stack.
+      llvm::Value *Stack = CreateTempAlloca(Int8PtrTy, "saved_stack");
+
+      llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
+      llvm::Value *V = Builder.CreateCall(F);
+
+      Builder.CreateStore(V, Stack);
+
+      DidCallStackSave = true;
+
+      // Push a cleanup block and restore the stack there.
+      // FIXME: in general circumstances, this should be an EH cleanup.
+      EHStack.pushCleanup<CallStackRestore>(NormalCleanup, Stack);
+    }
+
+    llvm::Value *elementCount;
+    QualType elementType;
+    llvm::tie(elementCount, elementType) = getVLASize(Ty);
+
+    llvm::Type *llvmTy = ConvertTypeForMem(elementType);
+
+    // Allocate memory for the array.
+    llvm::AllocaInst *vla = Builder.CreateAlloca(llvmTy, elementCount, "vla");
+    vla->setAlignment(alignment.getQuantity());
+
+    DeclPtr = vla;
+  }
+
+  llvm::Value *&DMEntry = LocalDeclMap[&D];
+  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
+  DMEntry = DeclPtr;
+  emission.Address = DeclPtr;
+
+  // Emit debug info for local var declaration.
+  if (HaveInsertPoint())
+    if (CGDebugInfo *DI = getDebugInfo()) {
+      DI->setLocation(D.getLocation());
+      if (Target.useGlobalsForAutomaticVariables()) {
+        DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
+      } else
+        DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
+    }
+
+  if (D.hasAttr<AnnotateAttr>())
+      EmitVarAnnotations(&D, emission.Address);
+
+  return emission;
+}
+
+/// Determines whether the given __block variable is potentially
+/// captured by the given expression.
+static bool isCapturedBy(const VarDecl &var, const Expr *e) {
+  // Skip the most common kinds of expressions that make
+  // hierarchy-walking expensive.
+  e = e->IgnoreParenCasts();
+
+  if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) {
+    const BlockDecl *block = be->getBlockDecl();
+    for (BlockDecl::capture_const_iterator i = block->capture_begin(),
+           e = block->capture_end(); i != e; ++i) {
+      if (i->getVariable() == &var)
+        return true;
+    }
+
+    // No need to walk into the subexpressions.
+    return false;
+  }
+
+  if (const StmtExpr *SE = dyn_cast<StmtExpr>(e)) {
+    const CompoundStmt *CS = SE->getSubStmt();
+    for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
+	   BE = CS->body_end(); BI != BE; ++BI)
+      if (Expr *E = dyn_cast<Expr>((*BI))) {
+        if (isCapturedBy(var, E))
+            return true;
+      }
+      else if (DeclStmt *DS = dyn_cast<DeclStmt>((*BI))) {
+          // special case declarations
+          for (DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
+               I != E; ++I) {
+              if (VarDecl *VD = dyn_cast<VarDecl>((*I))) {
+                Expr *Init = VD->getInit();
+                if (Init && isCapturedBy(var, Init))
+                  return true;
+              }
+          }
+      }
+      else
+        // FIXME. Make safe assumption assuming arbitrary statements cause capturing.
+        // Later, provide code to poke into statements for capture analysis.
+        return true;
+    return false;
+  }
+
+  for (Stmt::const_child_range children = e->children(); children; ++children)
+    if (isCapturedBy(var, cast<Expr>(*children)))
+      return true;
+
+  return false;
+}
+
+/// \brief Determine whether the given initializer is trivial in the sense
+/// that it requires no code to be generated.
+static bool isTrivialInitializer(const Expr *Init) {
+  if (!Init)
+    return true;
+
+  if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
+    if (CXXConstructorDecl *Constructor = Construct->getConstructor())
+      if (Constructor->isTrivial() &&
+          Constructor->isDefaultConstructor() &&
+          !Construct->requiresZeroInitialization())
+        return true;
+
+  return false;
+}
+void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
+  assert(emission.Variable && "emission was not valid!");
+
+  // If this was emitted as a global constant, we're done.
+  if (emission.wasEmittedAsGlobal()) return;
+
+  const VarDecl &D = *emission.Variable;
+  QualType type = D.getType();
+
+  // If this local has an initializer, emit it now.
+  const Expr *Init = D.getInit();
+
+  // If we are at an unreachable point, we don't need to emit the initializer
+  // unless it contains a label.
+  if (!HaveInsertPoint()) {
+    if (!Init || !ContainsLabel(Init)) return;
+    EnsureInsertPoint();
+  }
+
+  // Initialize the structure of a __block variable.
+  if (emission.IsByRef)
+    emitByrefStructureInit(emission);
+
+  if (isTrivialInitializer(Init))
+    return;
+
+  CharUnits alignment = emission.Alignment;
+
+  // Check whether this is a byref variable that's potentially
+  // captured and moved by its own initializer.  If so, we'll need to
+  // emit the initializer first, then copy into the variable.
+  bool capturedByInit = emission.IsByRef && isCapturedBy(D, Init);
+
+  llvm::Value *Loc =
+    capturedByInit ? emission.Address : emission.getObjectAddress(*this);
+
+  llvm::Constant *constant = 0;
+  if (emission.IsConstantAggregate) {
+    assert(!capturedByInit && "constant init contains a capturing block?");
+    constant = CGM.EmitConstantInit(D, this);
+  }
+
+  if (!constant) {
+    LValue lv = MakeAddrLValue(Loc, type, alignment);
+    lv.setNonGC(true);
+    return EmitExprAsInit(Init, &D, lv, capturedByInit);
+  }
+
+  // If this is a simple aggregate initialization, we can optimize it
+  // in various ways.
+  bool isVolatile = type.isVolatileQualified();
+
+  llvm::Value *SizeVal =
+    llvm::ConstantInt::get(IntPtrTy,
+                           getContext().getTypeSizeInChars(type).getQuantity());
+
+  llvm::Type *BP = Int8PtrTy;
+  if (Loc->getType() != BP)
+    Loc = Builder.CreateBitCast(Loc, BP);
+
+  // If the initializer is all or mostly zeros, codegen with memset then do
+  // a few stores afterward.
+  if (shouldUseMemSetPlusStoresToInitialize(constant,
+                CGM.getTargetData().getTypeAllocSize(constant->getType()))) {
+    Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), SizeVal,
+                         alignment.getQuantity(), isVolatile);
+    if (!constant->isNullValue()) {
+      Loc = Builder.CreateBitCast(Loc, constant->getType()->getPointerTo());
+      emitStoresForInitAfterMemset(constant, Loc, isVolatile, Builder);
+    }
+  } else {
+    // Otherwise, create a temporary global with the initializer then
+    // memcpy from the global to the alloca.
+    std::string Name = GetStaticDeclName(*this, D, ".");
+    llvm::GlobalVariable *GV =
+      new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true,
+                               llvm::GlobalValue::PrivateLinkage,
+                               constant, Name, 0, false, 0);
+    GV->setAlignment(alignment.getQuantity());
+    GV->setUnnamedAddr(true);
+
+    llvm::Value *SrcPtr = GV;
+    if (SrcPtr->getType() != BP)
+      SrcPtr = Builder.CreateBitCast(SrcPtr, BP);
+
+    Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, alignment.getQuantity(),
+                         isVolatile);
+  }
+}
+
+/// Emit an expression as an initializer for a variable at the given
+/// location.  The expression is not necessarily the normal
+/// initializer for the variable, and the address is not necessarily
+/// its normal location.
+///
+/// \param init the initializing expression
+/// \param var the variable to act as if we're initializing
+/// \param loc the address to initialize; its type is a pointer
+///   to the LLVM mapping of the variable's type
+/// \param alignment the alignment of the address
+/// \param capturedByInit true if the variable is a __block variable
+///   whose address is potentially changed by the initializer
+void CodeGenFunction::EmitExprAsInit(const Expr *init,
+                                     const ValueDecl *D,
+                                     LValue lvalue,
+                                     bool capturedByInit) {
+  QualType type = D->getType();
+
+  if (type->isReferenceType()) {
+    RValue rvalue = EmitReferenceBindingToExpr(init, D);
+    if (capturedByInit)
+      drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
+    EmitStoreThroughLValue(rvalue, lvalue, true);
+  } else if (!hasAggregateLLVMType(type)) {
+    EmitScalarInit(init, D, lvalue, capturedByInit);
+  } else if (type->isAnyComplexType()) {
+    ComplexPairTy complex = EmitComplexExpr(init);
+    if (capturedByInit)
+      drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
+    StoreComplexToAddr(complex, lvalue.getAddress(), lvalue.isVolatile());
+  } else {
+    // TODO: how can we delay here if D is captured by its initializer?
+    EmitAggExpr(init, AggValueSlot::forLValue(lvalue,
+                                              AggValueSlot::IsDestructed,
+                                         AggValueSlot::DoesNotNeedGCBarriers,
+                                              AggValueSlot::IsNotAliased));
+    MaybeEmitStdInitializerListCleanup(lvalue.getAddress(), init);
+  }
+}
+
+/// Enter a destroy cleanup for the given local variable.
+void CodeGenFunction::emitAutoVarTypeCleanup(
+                            const CodeGenFunction::AutoVarEmission &emission,
+                            QualType::DestructionKind dtorKind) {
+  assert(dtorKind != QualType::DK_none);
+
+  // Note that for __block variables, we want to destroy the
+  // original stack object, not the possibly forwarded object.
+  llvm::Value *addr = emission.getObjectAddress(*this);
+
+  const VarDecl *var = emission.Variable;
+  QualType type = var->getType();
+
+  CleanupKind cleanupKind = NormalAndEHCleanup;
+  CodeGenFunction::Destroyer *destroyer = 0;
+
+  switch (dtorKind) {
+  case QualType::DK_none:
+    llvm_unreachable("no cleanup for trivially-destructible variable");
+
+  case QualType::DK_cxx_destructor:
+    // If there's an NRVO flag on the emission, we need a different
+    // cleanup.
+    if (emission.NRVOFlag) {
+      assert(!type->isArrayType());
+      CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
+      EHStack.pushCleanup<DestroyNRVOVariable>(cleanupKind, addr, dtor,
+                                               emission.NRVOFlag);
+      return;
+    }
+    break;
+
+  case QualType::DK_objc_strong_lifetime:
+    // Suppress cleanups for pseudo-strong variables.
+    if (var->isARCPseudoStrong()) return;
+
+    // Otherwise, consider whether to use an EH cleanup or not.
+    cleanupKind = getARCCleanupKind();
+
+    // Use the imprecise destroyer by default.
+    if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
+      destroyer = CodeGenFunction::destroyARCStrongImprecise;
+    break;
+
+  case QualType::DK_objc_weak_lifetime:
+    break;
+  }
+
+  // If we haven't chosen a more specific destroyer, use the default.
+  if (!destroyer) destroyer = getDestroyer(dtorKind);
+
+  // Use an EH cleanup in array destructors iff the destructor itself
+  // is being pushed as an EH cleanup.
+  bool useEHCleanup = (cleanupKind & EHCleanup);
+  EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer,
+                                     useEHCleanup);
+}
+
+void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
+  assert(emission.Variable && "emission was not valid!");
+
+  // If this was emitted as a global constant, we're done.
+  if (emission.wasEmittedAsGlobal()) return;
+
+  // If we don't have an insertion point, we're done.  Sema prevents
+  // us from jumping into any of these scopes anyway.
+  if (!HaveInsertPoint()) return;
+
+  const VarDecl &D = *emission.Variable;
+
+  // Check the type for a cleanup.
+  if (QualType::DestructionKind dtorKind = D.getType().isDestructedType())
+    emitAutoVarTypeCleanup(emission, dtorKind);
+
+  // In GC mode, honor objc_precise_lifetime.
+  if (getLangOpts().getGC() != LangOptions::NonGC &&
+      D.hasAttr<ObjCPreciseLifetimeAttr>()) {
+    EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D);
+  }
+
+  // Handle the cleanup attribute.
+  if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
+    const FunctionDecl *FD = CA->getFunctionDecl();
+
+    llvm::Constant *F = CGM.GetAddrOfFunction(FD);
+    assert(F && "Could not find function!");
+
+    const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(FD);
+    EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D);
+  }
+
+  // If this is a block variable, call _Block_object_destroy
+  // (on the unforwarded address).
+  if (emission.IsByRef)
+    enterByrefCleanup(emission);
+}
+
+CodeGenFunction::Destroyer *
+CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
+  switch (kind) {
+  case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
+  case QualType::DK_cxx_destructor:
+    return destroyCXXObject;
+  case QualType::DK_objc_strong_lifetime:
+    return destroyARCStrongPrecise;
+  case QualType::DK_objc_weak_lifetime:
+    return destroyARCWeak;
+  }
+  llvm_unreachable("Unknown DestructionKind");
+}
+
+/// pushDestroy - Push the standard destructor for the given type.
+void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
+                                  llvm::Value *addr, QualType type) {
+  assert(dtorKind && "cannot push destructor for trivial type");
+
+  CleanupKind cleanupKind = getCleanupKind(dtorKind);
+  pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind),
+              cleanupKind & EHCleanup);
+}
+
+void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, llvm::Value *addr,
+                                  QualType type, Destroyer *destroyer,
+                                  bool useEHCleanupForArray) {
+  pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type,
+                                     destroyer, useEHCleanupForArray);
+}
+
+/// emitDestroy - Immediately perform the destruction of the given
+/// object.
+///
+/// \param addr - the address of the object; a type*
+/// \param type - the type of the object; if an array type, all
+///   objects are destroyed in reverse order
+/// \param destroyer - the function to call to destroy individual
+///   elements
+/// \param useEHCleanupForArray - whether an EH cleanup should be
+///   used when destroying array elements, in case one of the
+///   destructions throws an exception
+void CodeGenFunction::emitDestroy(llvm::Value *addr, QualType type,
+                                  Destroyer *destroyer,
+                                  bool useEHCleanupForArray) {
+  const ArrayType *arrayType = getContext().getAsArrayType(type);
+  if (!arrayType)
+    return destroyer(*this, addr, type);
+
+  llvm::Value *begin = addr;
+  llvm::Value *length = emitArrayLength(arrayType, type, begin);
+
+  // Normally we have to check whether the array is zero-length.
+  bool checkZeroLength = true;
+
+  // But if the array length is constant, we can suppress that.
+  if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) {
+    // ...and if it's constant zero, we can just skip the entire thing.
+    if (constLength->isZero()) return;
+    checkZeroLength = false;
+  }
+
+  llvm::Value *end = Builder.CreateInBoundsGEP(begin, length);
+  emitArrayDestroy(begin, end, type, destroyer,
+                   checkZeroLength, useEHCleanupForArray);
+}
+
+/// emitArrayDestroy - Destroys all the elements of the given array,
+/// beginning from last to first.  The array cannot be zero-length.
+///
+/// \param begin - a type* denoting the first element of the array
+/// \param end - a type* denoting one past the end of the array
+/// \param type - the element type of the array
+/// \param destroyer - the function to call to destroy elements
+/// \param useEHCleanup - whether to push an EH cleanup to destroy
+///   the remaining elements in case the destruction of a single
+///   element throws
+void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
+                                       llvm::Value *end,
+                                       QualType type,
+                                       Destroyer *destroyer,
+                                       bool checkZeroLength,
+                                       bool useEHCleanup) {
+  assert(!type->isArrayType());
+
+  // The basic structure here is a do-while loop, because we don't
+  // need to check for the zero-element case.
+  llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body");
+  llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done");
+
+  if (checkZeroLength) {
+    llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end,
+                                                "arraydestroy.isempty");
+    Builder.CreateCondBr(isEmpty, doneBB, bodyBB);
+  }
+
+  // Enter the loop body, making that address the current address.
+  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
+  EmitBlock(bodyBB);
+  llvm::PHINode *elementPast =
+    Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast");
+  elementPast->addIncoming(end, entryBB);
+
+  // Shift the address back by one element.
+  llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true);
+  llvm::Value *element = Builder.CreateInBoundsGEP(elementPast, negativeOne,
+                                                   "arraydestroy.element");
+
+  if (useEHCleanup)
+    pushRegularPartialArrayCleanup(begin, element, type, destroyer);
+
+  // Perform the actual destruction there.
+  destroyer(*this, element, type);
+
+  if (useEHCleanup)
+    PopCleanupBlock();
+
+  // Check whether we've reached the end.
+  llvm::Value *done = Builder.CreateICmpEQ(element, begin, "arraydestroy.done");
+  Builder.CreateCondBr(done, doneBB, bodyBB);
+  elementPast->addIncoming(element, Builder.GetInsertBlock());
+
+  // Done.
+  EmitBlock(doneBB);
+}
+
+/// Perform partial array destruction as if in an EH cleanup.  Unlike
+/// emitArrayDestroy, the element type here may still be an array type.
+static void emitPartialArrayDestroy(CodeGenFunction &CGF,
+                                    llvm::Value *begin, llvm::Value *end,
+                                    QualType type,
+                                    CodeGenFunction::Destroyer *destroyer) {
+  // If the element type is itself an array, drill down.
+  unsigned arrayDepth = 0;
+  while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(type)) {
+    // VLAs don't require a GEP index to walk into.
+    if (!isa<VariableArrayType>(arrayType))
+      arrayDepth++;
+    type = arrayType->getElementType();
+  }
+
+  if (arrayDepth) {
+    llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, arrayDepth+1);
+
+    SmallVector<llvm::Value*,4> gepIndices(arrayDepth, zero);
+    begin = CGF.Builder.CreateInBoundsGEP(begin, gepIndices, "pad.arraybegin");
+    end = CGF.Builder.CreateInBoundsGEP(end, gepIndices, "pad.arrayend");
+  }
+
+  // Destroy the array.  We don't ever need an EH cleanup because we
+  // assume that we're in an EH cleanup ourselves, so a throwing
+  // destructor causes an immediate terminate.
+  CGF.emitArrayDestroy(begin, end, type, destroyer,
+                       /*checkZeroLength*/ true, /*useEHCleanup*/ false);
+}
+
+namespace {
+  /// RegularPartialArrayDestroy - a cleanup which performs a partial
+  /// array destroy where the end pointer is regularly determined and
+  /// does not need to be loaded from a local.
+  class RegularPartialArrayDestroy : public EHScopeStack::Cleanup {
+    llvm::Value *ArrayBegin;
+    llvm::Value *ArrayEnd;
+    QualType ElementType;
+    CodeGenFunction::Destroyer *Destroyer;
+  public:
+    RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd,
+                               QualType elementType,
+                               CodeGenFunction::Destroyer *destroyer)
+      : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd),
+        ElementType(elementType), Destroyer(destroyer) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      emitPartialArrayDestroy(CGF, ArrayBegin, ArrayEnd,
+                              ElementType, Destroyer);
+    }
+  };
+
+  /// IrregularPartialArrayDestroy - a cleanup which performs a
+  /// partial array destroy where the end pointer is irregularly
+  /// determined and must be loaded from a local.
+  class IrregularPartialArrayDestroy : public EHScopeStack::Cleanup {
+    llvm::Value *ArrayBegin;
+    llvm::Value *ArrayEndPointer;
+    QualType ElementType;
+    CodeGenFunction::Destroyer *Destroyer;
+  public:
+    IrregularPartialArrayDestroy(llvm::Value *arrayBegin,
+                                 llvm::Value *arrayEndPointer,
+                                 QualType elementType,
+                                 CodeGenFunction::Destroyer *destroyer)
+      : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer),
+        ElementType(elementType), Destroyer(destroyer) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      llvm::Value *arrayEnd = CGF.Builder.CreateLoad(ArrayEndPointer);
+      emitPartialArrayDestroy(CGF, ArrayBegin, arrayEnd,
+                              ElementType, Destroyer);
+    }
+  };
+}
+
+/// pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy
+/// already-constructed elements of the given array.  The cleanup
+/// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
+///
+/// \param elementType - the immediate element type of the array;
+///   possibly still an array type
+/// \param array - a value of type elementType*
+/// \param destructionKind - the kind of destruction required
+/// \param initializedElementCount - a value of type size_t* holding
+///   the number of successfully-constructed elements
+void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
+                                                 llvm::Value *arrayEndPointer,
+                                                       QualType elementType,
+                                                       Destroyer *destroyer) {
+  pushFullExprCleanup<IrregularPartialArrayDestroy>(EHCleanup,
+                                                    arrayBegin, arrayEndPointer,
+                                                    elementType, destroyer);
+}
+
+/// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy
+/// already-constructed elements of the given array.  The cleanup
+/// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
+///
+/// \param elementType - the immediate element type of the array;
+///   possibly still an array type
+/// \param array - a value of type elementType*
+/// \param destructionKind - the kind of destruction required
+/// \param initializedElementCount - a value of type size_t* holding
+///   the number of successfully-constructed elements
+void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
+                                                     llvm::Value *arrayEnd,
+                                                     QualType elementType,
+                                                     Destroyer *destroyer) {
+  pushFullExprCleanup<RegularPartialArrayDestroy>(EHCleanup,
+                                                  arrayBegin, arrayEnd,
+                                                  elementType, destroyer);
+}
+
+namespace {
+  /// A cleanup to perform a release of an object at the end of a
+  /// function.  This is used to balance out the incoming +1 of a
+  /// ns_consumed argument when we can't reasonably do that just by
+  /// not doing the initial retain for a __block argument.
+  struct ConsumeARCParameter : EHScopeStack::Cleanup {
+    ConsumeARCParameter(llvm::Value *param) : Param(param) {}
+
+    llvm::Value *Param;
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      CGF.EmitARCRelease(Param, /*precise*/ false);
+    }
+  };
+}
+
+/// Emit an alloca (or GlobalValue depending on target)
+/// for the specified parameter and set up LocalDeclMap.
+void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
+                                   unsigned ArgNo) {
+  // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
+  assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
+         "Invalid argument to EmitParmDecl");
+
+  Arg->setName(D.getName());
+
+  // Use better IR generation for certain implicit parameters.
+  if (isa<ImplicitParamDecl>(D)) {
+    // The only implicit argument a block has is its literal.
+    if (BlockInfo) {
+      LocalDeclMap[&D] = Arg;
+
+      if (CGDebugInfo *DI = getDebugInfo()) {
+        DI->setLocation(D.getLocation());
+        DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, Builder);
+      }
+
+      return;
+    }
+  }
+
+  QualType Ty = D.getType();
+
+  llvm::Value *DeclPtr;
+  // If this is an aggregate or variable sized value, reuse the input pointer.
+  if (!Ty->isConstantSizeType() ||
+      CodeGenFunction::hasAggregateLLVMType(Ty)) {
+    DeclPtr = Arg;
+  } else {
+    // Otherwise, create a temporary to hold the value.
+    llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty),
+                                               D.getName() + ".addr");
+    Alloc->setAlignment(getContext().getDeclAlign(&D).getQuantity());
+    DeclPtr = Alloc;
+
+    bool doStore = true;
+
+    Qualifiers qs = Ty.getQualifiers();
+
+    if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) {
+      // We honor __attribute__((ns_consumed)) for types with lifetime.
+      // For __strong, it's handled by just skipping the initial retain;
+      // otherwise we have to balance out the initial +1 with an extra
+      // cleanup to do the release at the end of the function.
+      bool isConsumed = D.hasAttr<NSConsumedAttr>();
+
+      // 'self' is always formally __strong, but if this is not an
+      // init method then we don't want to retain it.
+      if (D.isARCPseudoStrong()) {
+        const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl);
+        assert(&D == method->getSelfDecl());
+        assert(lt == Qualifiers::OCL_Strong);
+        assert(qs.hasConst());
+        assert(method->getMethodFamily() != OMF_init);
+        (void) method;
+        lt = Qualifiers::OCL_ExplicitNone;
+      }
+
+      if (lt == Qualifiers::OCL_Strong) {
+        if (!isConsumed)
+          // Don't use objc_retainBlock for block pointers, because we
+          // don't want to Block_copy something just because we got it
+          // as a parameter.
+          Arg = EmitARCRetainNonBlock(Arg);
+      } else {
+        // Push the cleanup for a consumed parameter.
+        if (isConsumed)
+          EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), Arg);
+
+        if (lt == Qualifiers::OCL_Weak) {
+          EmitARCInitWeak(DeclPtr, Arg);
+          doStore = false; // The weak init is a store, no need to do two.
+        }
+      }
+
+      // Enter the cleanup scope.
+      EmitAutoVarWithLifetime(*this, D, DeclPtr, lt);
+    }
+
+    // Store the initial value into the alloca.
+    if (doStore) {
+      LValue lv = MakeAddrLValue(DeclPtr, Ty,
+                                 getContext().getDeclAlign(&D));
+      EmitStoreOfScalar(Arg, lv, /* isInitialization */ true);
+    }
+  }
+
+  llvm::Value *&DMEntry = LocalDeclMap[&D];
+  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
+  DMEntry = DeclPtr;
+
+  // Emit debug info for param declaration.
+  if (CGDebugInfo *DI = getDebugInfo())
+    DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);
+
+  if (D.hasAttr<AnnotateAttr>())
+      EmitVarAnnotations(&D, DeclPtr);
+}