Import Clang, at r72732.

1 files changed, 1543 insertions, 0 deletions

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
new file mode 100644
index 0000000..b69301e
--- /dev/null
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -0,0 +1,1543 @@
+//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This coordinates the per-module state used while generating code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenModule.h"
+#include "CGDebugInfo.h"
+#include "CodeGenFunction.h"
+#include "CGCall.h"
+#include "CGObjCRuntime.h"
+#include "Mangle.h"
+#include "clang/Frontend/CompileOptions.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/ConvertUTF.h"
+#include "llvm/CallingConv.h"
+#include "llvm/Module.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Target/TargetData.h"
+using namespace clang;
+using namespace CodeGen;
+
+
+CodeGenModule::CodeGenModule(ASTContext &C, const CompileOptions &compileOpts,
+                             llvm::Module &M, const llvm::TargetData &TD,
+                             Diagnostic &diags)
+  : BlockModule(C, M, TD, Types, *this), Context(C),
+    Features(C.getLangOptions()), CompileOpts(compileOpts), TheModule(M),
+    TheTargetData(TD), Diags(diags), Types(C, M, TD), Runtime(0),
+    MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0) {
+
+  if (!Features.ObjC1)
+    Runtime = 0;
+  else if (!Features.NeXTRuntime)
+    Runtime = CreateGNUObjCRuntime(*this);
+  else if (Features.ObjCNonFragileABI)
+    Runtime = CreateMacNonFragileABIObjCRuntime(*this);
+  else
+    Runtime = CreateMacObjCRuntime(*this);
+
+  // If debug info generation is enabled, create the CGDebugInfo object.
+  DebugInfo = CompileOpts.DebugInfo ? new CGDebugInfo(this) : 0;
+}
+
+CodeGenModule::~CodeGenModule() {
+  delete Runtime;
+  delete DebugInfo;
+}
+
+void CodeGenModule::Release() {
+  EmitDeferred();
+  if (Runtime)
+    if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction())
+      AddGlobalCtor(ObjCInitFunction);
+  EmitCtorList(GlobalCtors, "llvm.global_ctors");
+  EmitCtorList(GlobalDtors, "llvm.global_dtors");
+  EmitAnnotations();
+  EmitLLVMUsed();
+}
+
+/// ErrorUnsupported - Print out an error that codegen doesn't support the
+/// specified stmt yet.
+void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type,
+                                     bool OmitOnError) {
+  if (OmitOnError && getDiags().hasErrorOccurred())
+    return;
+  unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 
+                                               "cannot compile this %0 yet");
+  std::string Msg = Type;
+  getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
+    << Msg << S->getSourceRange();
+}
+
+/// ErrorUnsupported - Print out an error that codegen doesn't support the
+/// specified decl yet.
+void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type,
+                                     bool OmitOnError) {
+  if (OmitOnError && getDiags().hasErrorOccurred())
+    return;
+  unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 
+                                               "cannot compile this %0 yet");
+  std::string Msg = Type;
+  getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
+}
+
+LangOptions::VisibilityMode 
+CodeGenModule::getDeclVisibilityMode(const Decl *D) const {
+  if (const VarDecl *VD = dyn_cast<VarDecl>(D))
+    if (VD->getStorageClass() == VarDecl::PrivateExtern)
+      return LangOptions::Hidden;
+
+  if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) {
+    switch (attr->getVisibility()) {
+    default: assert(0 && "Unknown visibility!");
+    case VisibilityAttr::DefaultVisibility: 
+      return LangOptions::Default;
+    case VisibilityAttr::HiddenVisibility:
+      return LangOptions::Hidden;
+    case VisibilityAttr::ProtectedVisibility:
+      return LangOptions::Protected;
+    }
+  }
+
+  return getLangOptions().getVisibilityMode();
+}
+
+void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 
+                                        const Decl *D) const {
+  // Internal definitions always have default visibility.
+  if (GV->hasLocalLinkage()) {
+    GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
+    return;
+  }
+
+  switch (getDeclVisibilityMode(D)) {
+  default: assert(0 && "Unknown visibility!");
+  case LangOptions::Default:
+    return GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
+  case LangOptions::Hidden:
+    return GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
+  case LangOptions::Protected:
+    return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
+  }
+}
+
+const char *CodeGenModule::getMangledName(const GlobalDecl &GD) {
+  const NamedDecl *ND = GD.getDecl();
+  
+  if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
+    return getMangledCXXCtorName(D, GD.getCtorType());
+  if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
+    return getMangledCXXDtorName(D, GD.getDtorType());
+  
+  return getMangledName(ND);
+}
+
+/// \brief Retrieves the mangled name for the given declaration.
+///
+/// If the given declaration requires a mangled name, returns an
+/// const char* containing the mangled name.  Otherwise, returns
+/// the unmangled name.
+///
+const char *CodeGenModule::getMangledName(const NamedDecl *ND) {
+  // In C, functions with no attributes never need to be mangled. Fastpath them.
+  if (!getLangOptions().CPlusPlus && !ND->hasAttrs()) {
+    assert(ND->getIdentifier() && "Attempt to mangle unnamed decl.");
+    return ND->getNameAsCString();
+  }
+    
+  llvm::SmallString<256> Name;
+  llvm::raw_svector_ostream Out(Name);
+  if (!mangleName(ND, Context, Out)) {
+    assert(ND->getIdentifier() && "Attempt to mangle unnamed decl.");
+    return ND->getNameAsCString();
+  }
+
+  Name += '\0';
+  return UniqueMangledName(Name.begin(), Name.end());
+}
+
+const char *CodeGenModule::UniqueMangledName(const char *NameStart,
+                                             const char *NameEnd) {
+  assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!");
+  
+  return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData();
+}
+
+/// AddGlobalCtor - Add a function to the list that will be called before
+/// main() runs.
+void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
+  // FIXME: Type coercion of void()* types.
+  GlobalCtors.push_back(std::make_pair(Ctor, Priority));
+}
+
+/// AddGlobalDtor - Add a function to the list that will be called
+/// when the module is unloaded.
+void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
+  // FIXME: Type coercion of void()* types.
+  GlobalDtors.push_back(std::make_pair(Dtor, Priority));
+}
+
+void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
+  // Ctor function type is void()*.
+  llvm::FunctionType* CtorFTy =
+    llvm::FunctionType::get(llvm::Type::VoidTy, 
+                            std::vector<const llvm::Type*>(),
+                            false);
+  llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
+
+  // Get the type of a ctor entry, { i32, void ()* }.
+  llvm::StructType* CtorStructTy = 
+    llvm::StructType::get(llvm::Type::Int32Ty, 
+                          llvm::PointerType::getUnqual(CtorFTy), NULL);
+
+  // Construct the constructor and destructor arrays.
+  std::vector<llvm::Constant*> Ctors;
+  for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
+    std::vector<llvm::Constant*> S;
+    S.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, I->second, false));
+    S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy));
+    Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
+  }
+
+  if (!Ctors.empty()) {
+    llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
+    new llvm::GlobalVariable(AT, false,
+                             llvm::GlobalValue::AppendingLinkage,
+                             llvm::ConstantArray::get(AT, Ctors),
+                             GlobalName, 
+                             &TheModule);
+  }
+}
+
+void CodeGenModule::EmitAnnotations() {
+  if (Annotations.empty())
+    return;
+
+  // Create a new global variable for the ConstantStruct in the Module.
+  llvm::Constant *Array =
+  llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(),
+                                                Annotations.size()),
+                           Annotations);
+  llvm::GlobalValue *gv = 
+  new llvm::GlobalVariable(Array->getType(), false,  
+                           llvm::GlobalValue::AppendingLinkage, Array, 
+                           "llvm.global.annotations", &TheModule);
+  gv->setSection("llvm.metadata");
+}
+
+static CodeGenModule::GVALinkage
+GetLinkageForFunction(const FunctionDecl *FD, const LangOptions &Features) {
+  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
+    // C++ member functions defined inside the class are always inline.
+    if (MD->isInline() || !MD->isOutOfLineDefinition())
+      return CodeGenModule::GVA_CXXInline;
+    
+    return CodeGenModule::GVA_StrongExternal;
+  }
+  
+  // "static" functions get internal linkage.
+  if (FD->getStorageClass() == FunctionDecl::Static)
+    return CodeGenModule::GVA_Internal;
+
+  if (!FD->isInline())
+    return CodeGenModule::GVA_StrongExternal;
+  
+  // If the inline function explicitly has the GNU inline attribute on it, or if
+  // this is C89 mode, we use to GNU semantics.
+  if (!Features.C99 && !Features.CPlusPlus) {
+    // extern inline in GNU mode is like C99 inline.
+    if (FD->getStorageClass() == FunctionDecl::Extern)
+      return CodeGenModule::GVA_C99Inline;
+    // Normal inline is a strong symbol.
+    return CodeGenModule::GVA_StrongExternal;
+  } else if (FD->hasActiveGNUInlineAttribute()) {
+    // GCC in C99 mode seems to use a different decision-making
+    // process for extern inline, which factors in previous
+    // declarations.
+    if (FD->isExternGNUInline())
+      return CodeGenModule::GVA_C99Inline;
+    // Normal inline is a strong symbol.
+    return CodeGenModule::GVA_StrongExternal;
+  }
+
+  // The definition of inline changes based on the language.  Note that we
+  // have already handled "static inline" above, with the GVA_Internal case.
+  if (Features.CPlusPlus)  // inline and extern inline.
+    return CodeGenModule::GVA_CXXInline;
+  
+  assert(Features.C99 && "Must be in C99 mode if not in C89 or C++ mode");
+  if (FD->isC99InlineDefinition())
+    return CodeGenModule::GVA_C99Inline;
+
+  return CodeGenModule::GVA_StrongExternal;
+}
+
+/// SetFunctionDefinitionAttributes - Set attributes for a global.
+///
+/// FIXME: This is currently only done for aliases and functions, but not for
+/// variables (these details are set in EmitGlobalVarDefinition for variables).
+void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
+                                                    llvm::GlobalValue *GV) {
+  GVALinkage Linkage = GetLinkageForFunction(D, Features);
+
+  if (Linkage == GVA_Internal) {
+    GV->setLinkage(llvm::Function::InternalLinkage);
+  } else if (D->hasAttr<DLLExportAttr>()) {
+    GV->setLinkage(llvm::Function::DLLExportLinkage);
+  } else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) {
+    GV->setLinkage(llvm::Function::WeakAnyLinkage);
+  } else if (Linkage == GVA_C99Inline) {
+    // In C99 mode, 'inline' functions are guaranteed to have a strong
+    // definition somewhere else, so we can use available_externally linkage.
+    GV->setLinkage(llvm::Function::AvailableExternallyLinkage);
+  } else if (Linkage == GVA_CXXInline) {
+    // In C++, the compiler has to emit a definition in every translation unit
+    // that references the function.  We should use linkonce_odr because
+    // a) if all references in this translation unit are optimized away, we
+    // don't need to codegen it.  b) if the function persists, it needs to be
+    // merged with other definitions. c) C++ has the ODR, so we know the
+    // definition is dependable.
+    GV->setLinkage(llvm::Function::LinkOnceODRLinkage);
+  } else {
+    assert(Linkage == GVA_StrongExternal);
+    // Otherwise, we have strong external linkage.
+    GV->setLinkage(llvm::Function::ExternalLinkage);
+  }
+
+  SetCommonAttributes(D, GV);
+}
+
+void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
+                                              const CGFunctionInfo &Info, 
+                                              llvm::Function *F) {
+  AttributeListType AttributeList;
+  ConstructAttributeList(Info, D, AttributeList);
+
+  F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(),
+                                        AttributeList.size()));
+
+  // Set the appropriate calling convention for the Function.
+  if (D->hasAttr<FastCallAttr>())
+    F->setCallingConv(llvm::CallingConv::X86_FastCall);
+
+  if (D->hasAttr<StdCallAttr>())
+    F->setCallingConv(llvm::CallingConv::X86_StdCall);
+}
+
+void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
+                                                           llvm::Function *F) {
+  if (!Features.Exceptions && !Features.ObjCNonFragileABI)
+    F->addFnAttr(llvm::Attribute::NoUnwind);  
+
+  if (D->hasAttr<AlwaysInlineAttr>())
+    F->addFnAttr(llvm::Attribute::AlwaysInline);
+  
+  if (D->hasAttr<NoinlineAttr>())
+    F->addFnAttr(llvm::Attribute::NoInline);
+}
+
+void CodeGenModule::SetCommonAttributes(const Decl *D, 
+                                        llvm::GlobalValue *GV) {
+  setGlobalVisibility(GV, D);
+
+  if (D->hasAttr<UsedAttr>())
+    AddUsedGlobal(GV);
+
+  if (const SectionAttr *SA = D->getAttr<SectionAttr>())
+    GV->setSection(SA->getName());
+}
+
+void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
+                                                  llvm::Function *F,
+                                                  const CGFunctionInfo &FI) {
+  SetLLVMFunctionAttributes(D, FI, F);
+  SetLLVMFunctionAttributesForDefinition(D, F);
+
+  F->setLinkage(llvm::Function::InternalLinkage);
+
+  SetCommonAttributes(D, F);
+}
+
+void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
+                                          llvm::Function *F,
+                                          bool IsIncompleteFunction) {
+  if (!IsIncompleteFunction)
+    SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F);
+  
+  // Only a few attributes are set on declarations; these may later be
+  // overridden by a definition.
+  
+  if (FD->hasAttr<DLLImportAttr>()) {
+    F->setLinkage(llvm::Function::DLLImportLinkage);
+  } else if (FD->hasAttr<WeakAttr>() || FD->hasAttr<WeakImportAttr>()) {
+    // "extern_weak" is overloaded in LLVM; we probably should have
+    // separate linkage types for this. 
+    F->setLinkage(llvm::Function::ExternalWeakLinkage);
+  } else {
+    F->setLinkage(llvm::Function::ExternalLinkage); 
+  }
+
+  if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
+    F->setSection(SA->getName());
+}
+
+void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
+  assert(!GV->isDeclaration() && 
+         "Only globals with definition can force usage.");
+  LLVMUsed.push_back(GV);
+}
+
+void CodeGenModule::EmitLLVMUsed() {
+  // Don't create llvm.used if there is no need.
+  if (LLVMUsed.empty())
+    return;
+
+  llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+  llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, LLVMUsed.size());
+  
+  // Convert LLVMUsed to what ConstantArray needs.
+  std::vector<llvm::Constant*> UsedArray;
+  UsedArray.resize(LLVMUsed.size());
+  for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) {
+    UsedArray[i] = 
+     llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), i8PTy);
+  }
+  
+  llvm::GlobalVariable *GV = 
+    new llvm::GlobalVariable(ATy, false, 
+                             llvm::GlobalValue::AppendingLinkage,
+                             llvm::ConstantArray::get(ATy, UsedArray),
+                             "llvm.used", &getModule());
+
+  GV->setSection("llvm.metadata");
+}
+
+void CodeGenModule::EmitDeferred() {
+  // Emit code for any potentially referenced deferred decls.  Since a
+  // previously unused static decl may become used during the generation of code
+  // for a static function, iterate until no  changes are made.
+  while (!DeferredDeclsToEmit.empty()) {
+    GlobalDecl D = DeferredDeclsToEmit.back();
+    DeferredDeclsToEmit.pop_back();
+
+    // The mangled name for the decl must have been emitted in GlobalDeclMap.
+    // Look it up to see if it was defined with a stronger definition (e.g. an
+    // extern inline function with a strong function redefinition).  If so,
+    // just ignore the deferred decl.
+    llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)];
+    assert(CGRef && "Deferred decl wasn't referenced?");
+    
+    if (!CGRef->isDeclaration())
+      continue;
+    
+    // Otherwise, emit the definition and move on to the next one.
+    EmitGlobalDefinition(D);
+  }
+}
+
+/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 
+/// annotation information for a given GlobalValue.  The annotation struct is
+/// {i8 *, i8 *, i8 *, i32}.  The first field is a constant expression, the 
+/// GlobalValue being annotated.  The second field is the constant string 
+/// created from the AnnotateAttr's annotation.  The third field is a constant 
+/// string containing the name of the translation unit.  The fourth field is
+/// the line number in the file of the annotated value declaration.
+///
+/// FIXME: this does not unique the annotation string constants, as llvm-gcc
+///        appears to.
+///
+llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 
+                                                const AnnotateAttr *AA,
+                                                unsigned LineNo) {
+  llvm::Module *M = &getModule();
+
+  // get [N x i8] constants for the annotation string, and the filename string
+  // which are the 2nd and 3rd elements of the global annotation structure.
+  const llvm::Type *SBP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+  llvm::Constant *anno = llvm::ConstantArray::get(AA->getAnnotation(), true);
+  llvm::Constant *unit = llvm::ConstantArray::get(M->getModuleIdentifier(),
+                                                  true);
+
+  // Get the two global values corresponding to the ConstantArrays we just
+  // created to hold the bytes of the strings.
+  const char *StringPrefix = getContext().Target.getStringSymbolPrefix(true);
+  llvm::GlobalValue *annoGV = 
+  new llvm::GlobalVariable(anno->getType(), false,
+                           llvm::GlobalValue::InternalLinkage, anno,
+                           GV->getName() + StringPrefix, M);
+  // translation unit name string, emitted into the llvm.metadata section.
+  llvm::GlobalValue *unitGV =
+  new llvm::GlobalVariable(unit->getType(), false,
+                           llvm::GlobalValue::InternalLinkage, unit, 
+                           StringPrefix, M);
+
+  // Create the ConstantStruct for the global annotation.
+  llvm::Constant *Fields[4] = {
+    llvm::ConstantExpr::getBitCast(GV, SBP),
+    llvm::ConstantExpr::getBitCast(annoGV, SBP),
+    llvm::ConstantExpr::getBitCast(unitGV, SBP),
+    llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo)
+  };
+  return llvm::ConstantStruct::get(Fields, 4, false);
+}
+
+bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
+  // Never defer when EmitAllDecls is specified or the decl has
+  // attribute used.
+  if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>())
+    return false;
+
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
+    // Constructors and destructors should never be deferred.
+    if (FD->hasAttr<ConstructorAttr>() || FD->hasAttr<DestructorAttr>())
+      return false;
+
+    GVALinkage Linkage = GetLinkageForFunction(FD, Features);
+    
+    // static, static inline, always_inline, and extern inline functions can
+    // always be deferred.  Normal inline functions can be deferred in C99/C++.
+    if (Linkage == GVA_Internal || Linkage == GVA_C99Inline ||
+        Linkage == GVA_CXXInline)
+      return true;
+    return false;
+  }
+  
+  const VarDecl *VD = cast<VarDecl>(Global);
+  assert(VD->isFileVarDecl() && "Invalid decl");
+
+  return VD->getStorageClass() == VarDecl::Static;
+}
+
+void CodeGenModule::EmitGlobal(GlobalDecl GD) {
+  const ValueDecl *Global = GD.getDecl();
+  
+  // If this is an alias definition (which otherwise looks like a declaration)
+  // emit it now.
+  if (Global->hasAttr<AliasAttr>())
+    return EmitAliasDefinition(Global);
+
+  // Ignore declarations, they will be emitted on their first use.
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
+    // Forward declarations are emitted lazily on first use.
+    if (!FD->isThisDeclarationADefinition())
+      return;
+  } else {
+    const VarDecl *VD = cast<VarDecl>(Global);
+    assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
+
+    // In C++, if this is marked "extern", defer code generation.
+    if (getLangOptions().CPlusPlus && !VD->getInit() &&
+        (VD->getStorageClass() == VarDecl::Extern || 
+         VD->isExternC(getContext())))
+      return;
+
+    // In C, if this isn't a definition, defer code generation.
+    if (!getLangOptions().CPlusPlus && !VD->getInit())
+      return;
+  }
+
+  // Defer code generation when possible if this is a static definition, inline
+  // function etc.  These we only want to emit if they are used.
+  if (MayDeferGeneration(Global)) {
+    // If the value has already been used, add it directly to the
+    // DeferredDeclsToEmit list.
+    const char *MangledName = getMangledName(GD);
+    if (GlobalDeclMap.count(MangledName))
+      DeferredDeclsToEmit.push_back(GD);
+    else {
+      // Otherwise, remember that we saw a deferred decl with this name.  The
+      // first use of the mangled name will cause it to move into
+      // DeferredDeclsToEmit.
+      DeferredDecls[MangledName] = GD;
+    }
+    return;
+  }
+
+  // Otherwise emit the definition.
+  EmitGlobalDefinition(GD);
+}
+
+void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
+  const ValueDecl *D = GD.getDecl();
+  
+  if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
+    EmitCXXConstructor(CD, GD.getCtorType());
+  else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D))
+    EmitCXXDestructor(DD, GD.getDtorType());
+  else if (isa<FunctionDecl>(D))
+    EmitGlobalFunctionDefinition(GD);
+  else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
+    EmitGlobalVarDefinition(VD);
+  else {
+    assert(0 && "Invalid argument to EmitGlobalDefinition()");
+  }
+}
+
+/// GetOrCreateLLVMFunction - If the specified mangled name is not in the
+/// module, create and return an llvm Function with the specified type. If there
+/// is something in the module with the specified name, return it potentially
+/// bitcasted to the right type.
+///
+/// If D is non-null, it specifies a decl that correspond to this.  This is used
+/// to set the attributes on the function when it is first created.
+llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName,
+                                                       const llvm::Type *Ty,
+                                                       GlobalDecl D) {
+  // Lookup the entry, lazily creating it if necessary.
+  llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
+  if (Entry) {
+    if (Entry->getType()->getElementType() == Ty)
+      return Entry;
+    
+    // Make sure the result is of the correct type.
+    const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
+    return llvm::ConstantExpr::getBitCast(Entry, PTy);
+  }
+  
+  // This is the first use or definition of a mangled name.  If there is a
+  // deferred decl with this name, remember that we need to emit it at the end
+  // of the file.
+  llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 
+    DeferredDecls.find(MangledName);
+  if (DDI != DeferredDecls.end()) {
+    // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
+    // list, and remove it from DeferredDecls (since we don't need it anymore).
+    DeferredDeclsToEmit.push_back(DDI->second);
+    DeferredDecls.erase(DDI);
+  } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) {
+    // If this the first reference to a C++ inline function in a class, queue up
+    // the deferred function body for emission.  These are not seen as
+    // top-level declarations.
+    if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD))
+      DeferredDeclsToEmit.push_back(D);
+  }
+  
+  // This function doesn't have a complete type (for example, the return
+  // type is an incomplete struct). Use a fake type instead, and make
+  // sure not to try to set attributes.
+  bool IsIncompleteFunction = false;
+  if (!isa<llvm::FunctionType>(Ty)) {
+    Ty = llvm::FunctionType::get(llvm::Type::VoidTy,
+                                 std::vector<const llvm::Type*>(), false);
+    IsIncompleteFunction = true;
+  }
+  llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 
+                                             llvm::Function::ExternalLinkage,
+                                             "", &getModule());
+  F->setName(MangledName);
+  if (D.getDecl())
+    SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F,
+                          IsIncompleteFunction);
+  Entry = F;
+  return F;
+}
+
+/// GetAddrOfFunction - Return the address of the given function.  If Ty is
+/// non-null, then this function will use the specified type if it has to
+/// create it (this occurs when we see a definition of the function).
+llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
+                                                 const llvm::Type *Ty) {
+  // If there was no specific requested type, just convert it now.
+  if (!Ty)
+    Ty = getTypes().ConvertType(GD.getDecl()->getType());
+  return GetOrCreateLLVMFunction(getMangledName(GD.getDecl()), Ty, GD);
+}
+
+/// CreateRuntimeFunction - Create a new runtime function with the specified
+/// type and name.
+llvm::Constant *
+CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy,
+                                     const char *Name) {
+  // Convert Name to be a uniqued string from the IdentifierInfo table.
+  Name = getContext().Idents.get(Name).getName();
+  return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl());
+}
+
+/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
+/// create and return an llvm GlobalVariable with the specified type.  If there
+/// is something in the module with the specified name, return it potentially
+/// bitcasted to the right type.
+///
+/// If D is non-null, it specifies a decl that correspond to this.  This is used
+/// to set the attributes on the global when it is first created.
+llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
+                                                     const llvm::PointerType*Ty,
+                                                     const VarDecl *D) {
+  // Lookup the entry, lazily creating it if necessary.
+  llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
+  if (Entry) {
+    if (Entry->getType() == Ty)
+      return Entry;
+        
+    // Make sure the result is of the correct type.
+    return llvm::ConstantExpr::getBitCast(Entry, Ty);
+  }
+  
+  // This is the first use or definition of a mangled name.  If there is a
+  // deferred decl with this name, remember that we need to emit it at the end
+  // of the file.
+  llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 
+    DeferredDecls.find(MangledName);
+  if (DDI != DeferredDecls.end()) {
+    // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
+    // list, and remove it from DeferredDecls (since we don't need it anymore).
+    DeferredDeclsToEmit.push_back(DDI->second);
+    DeferredDecls.erase(DDI);
+  }
+  
+  llvm::GlobalVariable *GV = 
+    new llvm::GlobalVariable(Ty->getElementType(), false, 
+                             llvm::GlobalValue::ExternalLinkage,
+                             0, "", &getModule(), 
+                             false, Ty->getAddressSpace());
+  GV->setName(MangledName);
+
+  // Handle things which are present even on external declarations.
+  if (D) {
+    // FIXME: This code is overly simple and should be merged with other global
+    // handling.
+    GV->setConstant(D->getType().isConstant(Context));
+
+    // FIXME: Merge with other attribute handling code.
+    if (D->getStorageClass() == VarDecl::PrivateExtern)
+      GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
+
+    if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>())
+      GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+
+    GV->setThreadLocal(D->isThreadSpecified());
+  }
+  
+  return Entry = GV;
+}
+
+
+/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
+/// given global variable.  If Ty is non-null and if the global doesn't exist,
+/// then it will be greated with the specified type instead of whatever the
+/// normal requested type would be.
+llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
+                                                  const llvm::Type *Ty) {
+  assert(D->hasGlobalStorage() && "Not a global variable");
+  QualType ASTTy = D->getType();
+  if (Ty == 0)
+    Ty = getTypes().ConvertTypeForMem(ASTTy);
+  
+  const llvm::PointerType *PTy = 
+    llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
+  return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D);
+}
+
+/// CreateRuntimeVariable - Create a new runtime global variable with the
+/// specified type and name.
+llvm::Constant *
+CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty,
+                                     const char *Name) {
+  // Convert Name to be a uniqued string from the IdentifierInfo table.
+  Name = getContext().Idents.get(Name).getName();
+  return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0);
+}
+
+void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
+  assert(!D->getInit() && "Cannot emit definite definitions here!");
+
+  if (MayDeferGeneration(D)) {
+    // If we have not seen a reference to this variable yet, place it
+    // into the deferred declarations table to be emitted if needed
+    // later.
+    const char *MangledName = getMangledName(D);
+    if (GlobalDeclMap.count(MangledName) == 0) {
+      DeferredDecls[MangledName] = GlobalDecl(D);
+      return;
+    }
+  }
+
+  // The tentative definition is the only definition.
+  EmitGlobalVarDefinition(D);
+}
+
+void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
+  llvm::Constant *Init = 0;
+  QualType ASTTy = D->getType();
+  
+  if (D->getInit() == 0) {
+    // This is a tentative definition; tentative definitions are
+    // implicitly initialized with { 0 }.
+    //
+    // Note that tentative definitions are only emitted at the end of
+    // a translation unit, so they should never have incomplete
+    // type. In addition, EmitTentativeDefinition makes sure that we
+    // never attempt to emit a tentative definition if a real one
+    // exists. A use may still exists, however, so we still may need
+    // to do a RAUW.
+    assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
+    Init = llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(ASTTy));
+  } else {
+    Init = EmitConstantExpr(D->getInit(), D->getType());
+    if (!Init) {
+      ErrorUnsupported(D, "static initializer");
+      QualType T = D->getInit()->getType();
+      Init = llvm::UndefValue::get(getTypes().ConvertType(T));
+    }
+  }
+
+  const llvm::Type* InitType = Init->getType();
+  llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
+  
+  // Strip off a bitcast if we got one back.
+  if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
+    assert(CE->getOpcode() == llvm::Instruction::BitCast);
+    Entry = CE->getOperand(0);
+  }
+  
+  // Entry is now either a Function or GlobalVariable.
+  llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry);
+  
+  // We have a definition after a declaration with the wrong type.
+  // We must make a new GlobalVariable* and update everything that used OldGV
+  // (a declaration or tentative definition) with the new GlobalVariable*
+  // (which will be a definition).
+  //
+  // This happens if there is a prototype for a global (e.g.
+  // "extern int x[];") and then a definition of a different type (e.g.
+  // "int x[10];"). This also happens when an initializer has a different type
+  // from the type of the global (this happens with unions).
+  if (GV == 0 ||
+      GV->getType()->getElementType() != InitType ||
+      GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) {
+    
+    // Remove the old entry from GlobalDeclMap so that we'll create a new one.
+    GlobalDeclMap.erase(getMangledName(D));
+
+    // Make a new global with the correct type, this is now guaranteed to work.
+    GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
+    GV->takeName(cast<llvm::GlobalValue>(Entry));
+
+    // Replace all uses of the old global with the new global
+    llvm::Constant *NewPtrForOldDecl = 
+        llvm::ConstantExpr::getBitCast(GV, Entry->getType());
+    Entry->replaceAllUsesWith(NewPtrForOldDecl);
+
+    // Erase the old global, since it is no longer used.
+    cast<llvm::GlobalValue>(Entry)->eraseFromParent();
+  }
+
+  if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) {
+    SourceManager &SM = Context.getSourceManager();
+    AddAnnotation(EmitAnnotateAttr(GV, AA,
+                              SM.getInstantiationLineNumber(D->getLocation())));
+  }
+
+  GV->setInitializer(Init);
+  GV->setConstant(D->getType().isConstant(Context));
+  GV->setAlignment(getContext().getDeclAlignInBytes(D));
+
+  // Set the llvm linkage type as appropriate.
+  if (D->getStorageClass() == VarDecl::Static)
+    GV->setLinkage(llvm::Function::InternalLinkage);
+  else if (D->hasAttr<DLLImportAttr>())
+    GV->setLinkage(llvm::Function::DLLImportLinkage);
+  else if (D->hasAttr<DLLExportAttr>())
+    GV->setLinkage(llvm::Function::DLLExportLinkage);
+  else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>())
+    GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
+  else if (!CompileOpts.NoCommon &&
+           (!D->hasExternalStorage() && !D->getInit()))
+    GV->setLinkage(llvm::GlobalVariable::CommonLinkage);
+  else
+    GV->setLinkage(llvm::GlobalVariable::ExternalLinkage);
+
+  SetCommonAttributes(D, GV);
+
+  // Emit global variable debug information.
+  if (CGDebugInfo *DI = getDebugInfo()) {
+    DI->setLocation(D->getLocation());
+    DI->EmitGlobalVariable(GV, D);
+  }
+}
+
+/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
+/// implement a function with no prototype, e.g. "int foo() {}".  If there are
+/// existing call uses of the old function in the module, this adjusts them to
+/// call the new function directly.
+///
+/// This is not just a cleanup: the always_inline pass requires direct calls to
+/// functions to be able to inline them.  If there is a bitcast in the way, it
+/// won't inline them.  Instcombine normally deletes these calls, but it isn't
+/// run at -O0.
+static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
+                                                      llvm::Function *NewFn) {
+  // If we're redefining a global as a function, don't transform it.
+  llvm::Function *OldFn = dyn_cast<llvm::Function>(Old);
+  if (OldFn == 0) return;
+  
+  const llvm::Type *NewRetTy = NewFn->getReturnType();
+  llvm::SmallVector<llvm::Value*, 4> ArgList;
+
+  for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end();
+       UI != E; ) {
+    // TODO: Do invokes ever occur in C code?  If so, we should handle them too.
+    llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++);
+    if (!CI) continue;
+    
+    // If the return types don't match exactly, and if the call isn't dead, then
+    // we can't transform this call.
+    if (CI->getType() != NewRetTy && !CI->use_empty())
+      continue;
+
+    // If the function was passed too few arguments, don't transform.  If extra
+    // arguments were passed, we silently drop them.  If any of the types
+    // mismatch, we don't transform.
+    unsigned ArgNo = 0;
+    bool DontTransform = false;
+    for (llvm::Function::arg_iterator AI = NewFn->arg_begin(),
+         E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) {
+      if (CI->getNumOperands()-1 == ArgNo ||
+          CI->getOperand(ArgNo+1)->getType() != AI->getType()) {
+        DontTransform = true;
+        break;
+      }
+    }
+    if (DontTransform)
+      continue;
+    
+    // Okay, we can transform this.  Create the new call instruction and copy
+    // over the required information.
+    ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo);
+    llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(),
+                                                     ArgList.end(), "", CI);
+    ArgList.clear();
+    if (NewCall->getType() != llvm::Type::VoidTy)
+      NewCall->takeName(CI);
+    NewCall->setCallingConv(CI->getCallingConv());
+    NewCall->setAttributes(CI->getAttributes());
+
+    // Finally, remove the old call, replacing any uses with the new one.
+    if (!CI->use_empty())
+      CI->replaceAllUsesWith(NewCall);
+    CI->eraseFromParent();
+  }
+}
+
+
+void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
+  const llvm::FunctionType *Ty;
+  const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl());
+  
+  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
+    bool isVariadic = D->getType()->getAsFunctionProtoType()->isVariadic();
+    
+    Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic);
+  } else {
+    Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType()));
+    
+    // As a special case, make sure that definitions of K&R function
+    // "type foo()" aren't declared as varargs (which forces the backend
+    // to do unnecessary work).
+    if (D->getType()->isFunctionNoProtoType()) {
+      assert(Ty->isVarArg() && "Didn't lower type as expected");
+      // Due to stret, the lowered function could have arguments. 
+      // Just create the same type as was lowered by ConvertType 
+      // but strip off the varargs bit.
+      std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end());
+      Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false);
+    }
+  }
+
+  // Get or create the prototype for the function.
+  llvm::Constant *Entry = GetAddrOfFunction(GD, Ty);
+  
+  // Strip off a bitcast if we got one back.
+  if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
+    assert(CE->getOpcode() == llvm::Instruction::BitCast);
+    Entry = CE->getOperand(0);
+  }
+  
+  
+  if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) {
+    llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry);
+    
+    // If the types mismatch then we have to rewrite the definition.
+    assert(OldFn->isDeclaration() &&
+           "Shouldn't replace non-declaration");
+
+    // F is the Function* for the one with the wrong type, we must make a new
+    // Function* and update everything that used F (a declaration) with the new
+    // Function* (which will be a definition).
+    //
+    // This happens if there is a prototype for a function
+    // (e.g. "int f()") and then a definition of a different type
+    // (e.g. "int f(int x)").  Start by making a new function of the
+    // correct type, RAUW, then steal the name.
+    GlobalDeclMap.erase(getMangledName(D));
+    llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
+    NewFn->takeName(OldFn);
+    
+    // If this is an implementation of a function without a prototype, try to
+    // replace any existing uses of the function (which may be calls) with uses
+    // of the new function
+    if (D->getType()->isFunctionNoProtoType()) {
+      ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn);
+      OldFn->removeDeadConstantUsers();
+    }
+    
+    // Replace uses of F with the Function we will endow with a body.
+    if (!Entry->use_empty()) {
+      llvm::Constant *NewPtrForOldDecl = 
+        llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
+      Entry->replaceAllUsesWith(NewPtrForOldDecl);
+    }
+    
+    // Ok, delete the old function now, which is dead.
+    OldFn->eraseFromParent();
+    
+    Entry = NewFn;
+  }
+  
+  llvm::Function *Fn = cast<llvm::Function>(Entry);
+
+  CodeGenFunction(*this).GenerateCode(D, Fn);
+
+  SetFunctionDefinitionAttributes(D, Fn);
+  SetLLVMFunctionAttributesForDefinition(D, Fn);
+  
+  if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
+    AddGlobalCtor(Fn, CA->getPriority());
+  if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
+    AddGlobalDtor(Fn, DA->getPriority());
+}
+
+void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) {
+  const AliasAttr *AA = D->getAttr<AliasAttr>();
+  assert(AA && "Not an alias?");
+
+  const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
+  
+  // Unique the name through the identifier table.
+  const char *AliaseeName = AA->getAliasee().c_str();
+  AliaseeName = getContext().Idents.get(AliaseeName).getName();
+
+  // Create a reference to the named value.  This ensures that it is emitted
+  // if a deferred decl.
+  llvm::Constant *Aliasee;
+  if (isa<llvm::FunctionType>(DeclTy))
+    Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl());
+  else
+    Aliasee = GetOrCreateLLVMGlobal(AliaseeName,
+                                    llvm::PointerType::getUnqual(DeclTy), 0);
+
+  // Create the new alias itself, but don't set a name yet.
+  llvm::GlobalValue *GA = 
+    new llvm::GlobalAlias(Aliasee->getType(),
+                          llvm::Function::ExternalLinkage,
+                          "", Aliasee, &getModule());
+  
+  // See if there is already something with the alias' name in the module.
+  const char *MangledName = getMangledName(D);
+  llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
+  
+  if (Entry && !Entry->isDeclaration()) {
+    // If there is a definition in the module, then it wins over the alias.
+    // This is dubious, but allow it to be safe.  Just ignore the alias.
+    GA->eraseFromParent();
+    return;
+  }
+  
+  if (Entry) {
+    // If there is a declaration in the module, then we had an extern followed
+    // by the alias, as in:
+    //   extern int test6();
+    //   ...
+    //   int test6() __attribute__((alias("test7")));
+    //
+    // Remove it and replace uses of it with the alias.
+    
+    Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
+                                                          Entry->getType()));
+    Entry->eraseFromParent();
+  }
+  
+  // Now we know that there is no conflict, set the name.
+  Entry = GA;
+  GA->setName(MangledName);
+
+  // Set attributes which are particular to an alias; this is a
+  // specialization of the attributes which may be set on a global
+  // variable/function.
+  if (D->hasAttr<DLLExportAttr>()) {
+    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+      // The dllexport attribute is ignored for undefined symbols.
+      if (FD->getBody(getContext()))
+        GA->setLinkage(llvm::Function::DLLExportLinkage);
+    } else {
+      GA->setLinkage(llvm::Function::DLLExportLinkage);
+    }
+  } else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) {
+    GA->setLinkage(llvm::Function::WeakAnyLinkage);
+  }
+
+  SetCommonAttributes(D, GA);
+}
+
+/// getBuiltinLibFunction - Given a builtin id for a function like
+/// "__builtin_fabsf", return a Function* for "fabsf".
+llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) {
+  assert((Context.BuiltinInfo.isLibFunction(BuiltinID) ||
+          Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 
+         "isn't a lib fn");
+  
+  // Get the name, skip over the __builtin_ prefix (if necessary).
+  const char *Name = Context.BuiltinInfo.GetName(BuiltinID);
+  if (Context.BuiltinInfo.isLibFunction(BuiltinID))
+    Name += 10;
+  
+  // Get the type for the builtin.
+  Builtin::Context::GetBuiltinTypeError Error;
+  QualType Type = Context.BuiltinInfo.GetBuiltinType(BuiltinID, Context, Error);
+  assert(Error == Builtin::Context::GE_None && "Can't get builtin type");
+
+  const llvm::FunctionType *Ty = 
+    cast<llvm::FunctionType>(getTypes().ConvertType(Type));
+
+  // Unique the name through the identifier table.
+  Name = getContext().Idents.get(Name).getName();
+  // FIXME: param attributes for sext/zext etc.
+  return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
+}
+
+llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys,
+                                            unsigned NumTys) {
+  return llvm::Intrinsic::getDeclaration(&getModule(),
+                                         (llvm::Intrinsic::ID)IID, Tys, NumTys);
+}
+
+llvm::Function *CodeGenModule::getMemCpyFn() {
+  if (MemCpyFn) return MemCpyFn;
+  const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
+  return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1);
+}
+
+llvm::Function *CodeGenModule::getMemMoveFn() {
+  if (MemMoveFn) return MemMoveFn;
+  const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
+  return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1);
+}
+
+llvm::Function *CodeGenModule::getMemSetFn() {
+  if (MemSetFn) return MemSetFn;
+  const llvm::Type *IntPtr = TheTargetData.getIntPtrType();
+  return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1);
+}
+
+static void appendFieldAndPadding(CodeGenModule &CGM,
+                                  std::vector<llvm::Constant*>& Fields,
+                                  FieldDecl *FieldD, FieldDecl *NextFieldD,
+                                  llvm::Constant* Field,
+                                  RecordDecl* RD, const llvm::StructType *STy) {
+  // Append the field.
+  Fields.push_back(Field);
+  
+  int StructFieldNo = CGM.getTypes().getLLVMFieldNo(FieldD);
+  
+  int NextStructFieldNo;
+  if (!NextFieldD) {
+    NextStructFieldNo = STy->getNumElements();
+  } else {
+    NextStructFieldNo = CGM.getTypes().getLLVMFieldNo(NextFieldD);
+  }
+  
+  // Append padding
+  for (int i = StructFieldNo + 1; i < NextStructFieldNo; i++) {
+    llvm::Constant *C = 
+      llvm::Constant::getNullValue(STy->getElementType(StructFieldNo + 1));
+    
+    Fields.push_back(C);
+  }
+}
+
+llvm::Constant *CodeGenModule::
+GetAddrOfConstantCFString(const StringLiteral *Literal) {
+  std::string str;
+  unsigned StringLength = 0;
+  
+  bool isUTF16 = false;
+  if (Literal->containsNonAsciiOrNull()) {
+    // Convert from UTF-8 to UTF-16.
+    llvm::SmallVector<UTF16, 128> ToBuf(Literal->getByteLength());
+    const UTF8 *FromPtr = (UTF8 *)Literal->getStrData();
+    UTF16 *ToPtr = &ToBuf[0];
+        
+    ConversionResult Result;
+    Result = ConvertUTF8toUTF16(&FromPtr, FromPtr+Literal->getByteLength(),
+                                &ToPtr, ToPtr+Literal->getByteLength(),
+                                strictConversion);
+    if (Result == conversionOK) {
+      // FIXME: Storing UTF-16 in a C string is a hack to test Unicode strings
+      // without doing more surgery to this routine. Since we aren't explicitly
+      // checking for endianness here, it's also a bug (when generating code for
+      // a target that doesn't match the host endianness). Modeling this as an
+      // i16 array is likely the cleanest solution.
+      StringLength = ToPtr-&ToBuf[0];
+      str.assign((char *)&ToBuf[0], StringLength*2);// Twice as many UTF8 chars.
+      isUTF16 = true;
+    } else if (Result == sourceIllegal) {
+      // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string.
+      str.assign(Literal->getStrData(), Literal->getByteLength());
+      StringLength = str.length();
+    } else
+      assert(Result == conversionOK && "UTF-8 to UTF-16 conversion failed");
+    
+  } else {
+    str.assign(Literal->getStrData(), Literal->getByteLength());
+    StringLength = str.length();
+  }
+  llvm::StringMapEntry<llvm::Constant *> &Entry = 
+    CFConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]);
+  
+  if (llvm::Constant *C = Entry.getValue())
+    return C;
+  
+  llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty);
+  llvm::Constant *Zeros[] = { Zero, Zero };
+  
+  if (!CFConstantStringClassRef) {
+    const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
+    Ty = llvm::ArrayType::get(Ty, 0);
+
+    // FIXME: This is fairly broken if __CFConstantStringClassReference is
+    // already defined, in that it will get renamed and the user will most
+    // likely see an opaque error message. This is a general issue with relying
+    // on particular names.
+    llvm::GlobalVariable *GV = 
+      new llvm::GlobalVariable(Ty, false,
+                               llvm::GlobalVariable::ExternalLinkage, 0, 
+                               "__CFConstantStringClassReference", 
+                               &getModule());
+    
+    // Decay array -> ptr
+    CFConstantStringClassRef =
+      llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2);
+  }
+  
+  QualType CFTy = getContext().getCFConstantStringType();
+  RecordDecl *CFRD = CFTy->getAsRecordType()->getDecl();
+
+  const llvm::StructType *STy = 
+    cast<llvm::StructType>(getTypes().ConvertType(CFTy));
+
+  std::vector<llvm::Constant*> Fields;
+  RecordDecl::field_iterator Field = CFRD->field_begin(getContext());
+
+  // Class pointer.
+  FieldDecl *CurField = *Field++;
+  FieldDecl *NextField = *Field++;
+  appendFieldAndPadding(*this, Fields, CurField, NextField,
+                        CFConstantStringClassRef, CFRD, STy);
+  
+  // Flags.
+  CurField = NextField;
+  NextField = *Field++;
+  const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
+  appendFieldAndPadding(*this, Fields, CurField, NextField,
+                        isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0)
+                                : llvm::ConstantInt::get(Ty, 0x07C8), 
+                        CFRD, STy);
+    
+  // String pointer.
+  CurField = NextField;
+  NextField = *Field++;
+  llvm::Constant *C = llvm::ConstantArray::get(str);
+
+  const char *Sect, *Prefix;
+  bool isConstant;
+  if (isUTF16) {
+    Prefix = getContext().Target.getUnicodeStringSymbolPrefix();
+    Sect = getContext().Target.getUnicodeStringSection();
+    // FIXME: Why does GCC not set constant here?
+    isConstant = false;
+  } else {
+    Prefix = getContext().Target.getStringSymbolPrefix(true);
+    Sect = getContext().Target.getCFStringDataSection();
+    // FIXME: -fwritable-strings should probably affect this, but we
+    // are following gcc here.
+    isConstant = true;
+  }
+  llvm::GlobalVariable *GV = 
+    new llvm::GlobalVariable(C->getType(), isConstant, 
+                             llvm::GlobalValue::InternalLinkage,
+                             C, Prefix, &getModule());
+  if (Sect)
+    GV->setSection(Sect);
+  if (isUTF16) {
+    unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8;
+    GV->setAlignment(Align); 
+  }
+  appendFieldAndPadding(*this, Fields, CurField, NextField,
+                        llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2),
+                        CFRD, STy);
+  
+  // String length.
+  CurField = NextField;
+  NextField = 0;
+  Ty = getTypes().ConvertType(getContext().LongTy);
+  appendFieldAndPadding(*this, Fields, CurField, NextField,
+                        llvm::ConstantInt::get(Ty, StringLength), CFRD, STy);
+  
+  // The struct.
+  C = llvm::ConstantStruct::get(STy, Fields);
+  GV = new llvm::GlobalVariable(C->getType(), true, 
+                                llvm::GlobalVariable::InternalLinkage, C, 
+                                getContext().Target.getCFStringSymbolPrefix(), 
+                                &getModule());
+  if (const char *Sect = getContext().Target.getCFStringSection())
+    GV->setSection(Sect);
+  Entry.setValue(GV);
+  
+  return GV;
+}
+
+/// GetStringForStringLiteral - Return the appropriate bytes for a
+/// string literal, properly padded to match the literal type.
+std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) {
+  const char *StrData = E->getStrData();
+  unsigned Len = E->getByteLength();
+
+  const ConstantArrayType *CAT =
+    getContext().getAsConstantArrayType(E->getType());
+  assert(CAT && "String isn't pointer or array!");
+  
+  // Resize the string to the right size.
+  std::string Str(StrData, StrData+Len);
+  uint64_t RealLen = CAT->getSize().getZExtValue();
+  
+  if (E->isWide())
+    RealLen *= getContext().Target.getWCharWidth()/8;
+  
+  Str.resize(RealLen, '\0');
+  
+  return Str;
+}
+
+/// GetAddrOfConstantStringFromLiteral - Return a pointer to a
+/// constant array for the given string literal.
+llvm::Constant *
+CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
+  // FIXME: This can be more efficient.
+  return GetAddrOfConstantString(GetStringForStringLiteral(S));
+}
+
+/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
+/// array for the given ObjCEncodeExpr node.
+llvm::Constant *
+CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
+  std::string Str;
+  getContext().getObjCEncodingForType(E->getEncodedType(), Str);
+
+  return GetAddrOfConstantCString(Str);
+}
+
+
+/// GenerateWritableString -- Creates storage for a string literal.
+static llvm::Constant *GenerateStringLiteral(const std::string &str, 
+                                             bool constant,
+                                             CodeGenModule &CGM,
+                                             const char *GlobalName) {
+  // Create Constant for this string literal. Don't add a '\0'.
+  llvm::Constant *C = llvm::ConstantArray::get(str, false);
+  
+  // Create a global variable for this string
+  return new llvm::GlobalVariable(C->getType(), constant, 
+                                  llvm::GlobalValue::InternalLinkage,
+                                  C, GlobalName, &CGM.getModule());
+}
+
+/// GetAddrOfConstantString - Returns a pointer to a character array
+/// containing the literal. This contents are exactly that of the
+/// given string, i.e. it will not be null terminated automatically;
+/// see GetAddrOfConstantCString. Note that whether the result is
+/// actually a pointer to an LLVM constant depends on
+/// Feature.WriteableStrings.
+///
+/// The result has pointer to array type.
+llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str,
+                                                       const char *GlobalName) {
+  bool IsConstant = !Features.WritableStrings;
+
+  // Get the default prefix if a name wasn't specified.
+  if (!GlobalName)
+    GlobalName = getContext().Target.getStringSymbolPrefix(IsConstant);
+
+  // Don't share any string literals if strings aren't constant.
+  if (!IsConstant)
+    return GenerateStringLiteral(str, false, *this, GlobalName);
+  
+  llvm::StringMapEntry<llvm::Constant *> &Entry = 
+  ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]);
+
+  if (Entry.getValue())
+    return Entry.getValue();
+
+  // Create a global variable for this.
+  llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName);
+  Entry.setValue(C);
+  return C;
+}
+
+/// GetAddrOfConstantCString - Returns a pointer to a character
+/// array containing the literal and a terminating '\-'
+/// character. The result has pointer to array type.
+llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str,
+                                                        const char *GlobalName){
+  return GetAddrOfConstantString(str + '\0', GlobalName);
+}
+
+/// EmitObjCPropertyImplementations - Emit information for synthesized
+/// properties for an implementation.
+void CodeGenModule::EmitObjCPropertyImplementations(const 
+                                                    ObjCImplementationDecl *D) {
+  for (ObjCImplementationDecl::propimpl_iterator 
+         i = D->propimpl_begin(getContext()),
+         e = D->propimpl_end(getContext()); i != e; ++i) {
+    ObjCPropertyImplDecl *PID = *i;
+    
+    // Dynamic is just for type-checking.
+    if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
+      ObjCPropertyDecl *PD = PID->getPropertyDecl();
+
+      // Determine which methods need to be implemented, some may have
+      // been overridden. Note that ::isSynthesized is not the method
+      // we want, that just indicates if the decl came from a
+      // property. What we want to know is if the method is defined in
+      // this implementation.
+      if (!D->getInstanceMethod(getContext(), PD->getGetterName()))
+        CodeGenFunction(*this).GenerateObjCGetter(
+                                 const_cast<ObjCImplementationDecl *>(D), PID);
+      if (!PD->isReadOnly() &&
+          !D->getInstanceMethod(getContext(), PD->getSetterName()))
+        CodeGenFunction(*this).GenerateObjCSetter(
+                                 const_cast<ObjCImplementationDecl *>(D), PID);
+    }
+  }
+}
+
+/// EmitNamespace - Emit all declarations in a namespace.
+void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
+  for (RecordDecl::decl_iterator I = ND->decls_begin(getContext()),
+         E = ND->decls_end(getContext());
+       I != E; ++I)
+    EmitTopLevelDecl(*I);
+}
+
+// EmitLinkageSpec - Emit all declarations in a linkage spec.
+void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
+  if (LSD->getLanguage() != LinkageSpecDecl::lang_c) {
+    ErrorUnsupported(LSD, "linkage spec");
+    return;
+  }
+
+  for (RecordDecl::decl_iterator I = LSD->decls_begin(getContext()),
+         E = LSD->decls_end(getContext());
+       I != E; ++I)
+    EmitTopLevelDecl(*I);
+}
+
+/// EmitTopLevelDecl - Emit code for a single top level declaration.
+void CodeGenModule::EmitTopLevelDecl(Decl *D) {
+  // If an error has occurred, stop code generation, but continue
+  // parsing and semantic analysis (to ensure all warnings and errors
+  // are emitted).
+  if (Diags.hasErrorOccurred())
+    return;
+
+  switch (D->getKind()) {
+  case Decl::CXXMethod:
+  case Decl::Function:
+  case Decl::Var:
+    EmitGlobal(GlobalDecl(cast<ValueDecl>(D)));
+    break;
+
+  // C++ Decls
+  case Decl::Namespace:
+    EmitNamespace(cast<NamespaceDecl>(D));
+    break;
+  case Decl::CXXConstructor:
+    EmitCXXConstructors(cast<CXXConstructorDecl>(D));
+    break;
+  case Decl::CXXDestructor:
+    EmitCXXDestructors(cast<CXXDestructorDecl>(D));
+    break;
+        
+  // Objective-C Decls
+    
+  // Forward declarations, no (immediate) code generation.
+  case Decl::ObjCClass:
+  case Decl::ObjCForwardProtocol:
+  case Decl::ObjCCategory:
+  case Decl::ObjCInterface:
+    break;
+
+  case Decl::ObjCProtocol:
+    Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D));
+    break;
+
+  case Decl::ObjCCategoryImpl:
+    // Categories have properties but don't support synthesize so we
+    // can ignore them here.
+    Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
+    break;
+
+  case Decl::ObjCImplementation: {
+    ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D);
+    EmitObjCPropertyImplementations(OMD);
+    Runtime->GenerateClass(OMD);
+    break;
+  } 
+  case Decl::ObjCMethod: {
+    ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D);
+    // If this is not a prototype, emit the body.
+    if (OMD->getBody(getContext()))
+      CodeGenFunction(*this).GenerateObjCMethod(OMD);
+    break;
+  }
+  case Decl::ObjCCompatibleAlias: 
+    // compatibility-alias is a directive and has no code gen.
+    break;
+
+  case Decl::LinkageSpec:
+    EmitLinkageSpec(cast<LinkageSpecDecl>(D));
+    break;
+
+  case Decl::FileScopeAsm: {
+    FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D);
+    std::string AsmString(AD->getAsmString()->getStrData(),
+                          AD->getAsmString()->getByteLength());
+    
+    const std::string &S = getModule().getModuleInlineAsm();
+    if (S.empty())
+      getModule().setModuleInlineAsm(AsmString);
+    else
+      getModule().setModuleInlineAsm(S + '\n' + AsmString);
+    break;
+  }
+   
+  default: 
+    // Make sure we handled everything we should, every other kind is a
+    // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
+    // function. Need to recode Decl::Kind to do that easily.
+    assert(isa<TypeDecl>(D) && "Unsupported decl kind");
+  }
+}