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llvm-project/clang/lib/CodeGen/CodeGenModule.cpp

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//===--- 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) {
// "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) {
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(const 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->getStorageClass() == VarDecl::Extern && !VD->getInit())
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(const GlobalDecl &GD) {
const ValueDecl *D = GD.getDecl();
if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
EmitCXXConstructor(CD, GD.getCtorType());
else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
EmitGlobalFunctionDefinition(FD);
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,
const FunctionDecl *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);
}
// 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 ShouldSetAttributes = true;
if (!isa<llvm::FunctionType>(Ty)) {
Ty = llvm::FunctionType::get(llvm::Type::VoidTy,
std::vector<const llvm::Type*>(), false);
ShouldSetAttributes = false;
}
llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty),
llvm::Function::ExternalLinkage,
"", &getModule());
F->setName(MangledName);
if (D && ShouldSetAttributes)
SetFunctionAttributes(D, F);
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(const FunctionDecl *D,
const llvm::Type *Ty) {
// If there was no specific requested type, just convert it now.
if (!Ty)
Ty = getTypes().ConvertType(D->getType());
return GetOrCreateLLVMFunction(getMangledName(D), Ty, D);
}
/// 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, 0);
}
/// 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(const FunctionDecl *D) {
const llvm::FunctionType *Ty;
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(D, 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(D, 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, 0);
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, 0);
}
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");
}
}
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