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gerrit-public.fairphone.software / platform / external / clang / b681b8ffab2aa016b3897916d5110927c34a584b / . / 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 "CGDebugInfo.h"
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "CGCall.h"
#include "CGObjCRuntime.h"
#include "Mangle.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 "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 LangOptions &LO,
llvm::Module &M, const llvm::TargetData &TD,
Diagnostic &diags, bool GenerateDebugInfo)
: BlockModule(C, M, TD, Types, *this), Context(C), Features(LO), TheModule(M),
TheTargetData(TD), Diags(diags), Types(C, M, TD), Runtime(0),
MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0) {
if (Features.ObjC1) {
if (Features.NeXTRuntime) {
Runtime = Features.ObjCNonFragileABI ? CreateMacNonFragileABIObjCRuntime(*this)
: CreateMacObjCRuntime(*this);
} else {
Runtime = CreateGNUObjCRuntime(*this);
}
}
// If debug info generation is enabled, create the CGDebugInfo object.
DebugInfo = GenerateDebugInfo ? new CGDebugInfo(this) : 0;
}
CodeGenModule::~CodeGenModule() {
delete Runtime;
delete DebugInfo;
}
void CodeGenModule::Release() {
EmitDeferred();
EmitAliases();
if (Runtime)
if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction())
AddGlobalCtor(ObjCInitFunction);
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
EmitAnnotations();
EmitLLVMUsed();
BindRuntimeGlobals();
}
void CodeGenModule::BindRuntimeGlobals() {
// Deal with protecting runtime function names.
for (unsigned i = 0, e = RuntimeGlobals.size(); i < e; ++i) {
llvm::GlobalValue *GV = RuntimeGlobals[i].first;
const std::string &Name = RuntimeGlobals[i].second;
// Discard unused runtime declarations.
if (GV->isDeclaration() && GV->use_empty()) {
GV->eraseFromParent();
continue;
}
// See if there is a conflict against a function.
llvm::GlobalValue *Conflict = TheModule.getNamedValue(Name);
if (Conflict) {
// Decide which version to take. If the conflict is a definition
// we are forced to take that, otherwise assume the runtime
// knows best.
// FIXME: This will fail phenomenally when the conflict is the
// wrong type of value. Just bail on it for now. This should
// really reuse something inside the LLVM Linker code.
assert(GV->getValueID() == Conflict->getValueID() &&
"Unable to resolve conflict between globals of different types.");
if (!Conflict->isDeclaration()) {
llvm::Value *Casted =
llvm::ConstantExpr::getBitCast(Conflict, GV->getType());
GV->replaceAllUsesWith(Casted);
GV->eraseFromParent();
} else {
GV->takeName(Conflict);
llvm::Value *Casted =
llvm::ConstantExpr::getBitCast(GV, Conflict->getType());
Conflict->replaceAllUsesWith(Casted);
Conflict->eraseFromParent();
}
} else
GV->setName(Name);
}
}
/// 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;
}
/// setGlobalVisibility - Set the visibility for the given LLVM
/// GlobalValue according to the given clang AST visibility value.
static void setGlobalVisibility(llvm::GlobalValue *GV,
VisibilityAttr::VisibilityTypes Vis) {
switch (Vis) {
default: assert(0 && "Unknown visibility!");
case VisibilityAttr::DefaultVisibility:
GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
break;
case VisibilityAttr::HiddenVisibility:
GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
break;
case VisibilityAttr::ProtectedVisibility:
GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
break;
}
}
/// \brief Retrieves the mangled name for the given declaration.
///
/// If the given declaration requires a mangled name, returns an
/// IdentifierInfo* containing the mangled name. Otherwise, returns
/// the name of the declaration as an identifier.
///
/// FIXME: Returning an IdentifierInfo* here is a total hack. We
/// really need some kind of string abstraction that either stores a
/// mangled name or stores an IdentifierInfo*. This will require
/// changes to the GlobalDeclMap, too. (I disagree, I think what we
/// actually need is for Sema to provide some notion of which Decls
/// refer to the same semantic decl. We shouldn't need to mangle the
/// names and see what comes out the same to figure this out. - DWD)
///
/// FIXME: Performance here is going to be terribly until we start
/// caching mangled names. However, we should fix the problem above
/// first.
const char *CodeGenModule::getMangledName(const NamedDecl *ND) {
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->getIdentifier()->getName();
}
Name += '\0';
return MangledNames.GetOrCreateValue(Name.begin(), Name.end())
.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");
}
void CodeGenModule::SetGlobalValueAttributes(const Decl *D,
bool IsInternal,
bool IsInline,
llvm::GlobalValue *GV,
bool ForDefinition) {
// FIXME: Set up linkage and many other things. Note, this is a simple
// approximation of what we really want.
if (!ForDefinition) {
// Only a few attributes are set on declarations.
if (D->getAttr<DLLImportAttr>()) {
// The dllimport attribute is overridden by a subsequent declaration as
// dllexport.
if (!D->getAttr<DLLExportAttr>()) {
// dllimport attribute can be applied only to function decls, not to
// definitions.
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (!FD->getBody())
GV->setLinkage(llvm::Function::DLLImportLinkage);
} else
GV->setLinkage(llvm::Function::DLLImportLinkage);
}
} else if (D->getAttr<WeakAttr>() ||
D->getAttr<WeakImportAttr>()) {
// "extern_weak" is overloaded in LLVM; we probably should have
// separate linkage types for this.
GV->setLinkage(llvm::Function::ExternalWeakLinkage);
}
} else {
if (IsInternal) {
GV->setLinkage(llvm::Function::InternalLinkage);
} else {
if (D->getAttr<DLLExportAttr>()) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
// The dllexport attribute is ignored for undefined symbols.
if (FD->getBody())
GV->setLinkage(llvm::Function::DLLExportLinkage);
} else
GV->setLinkage(llvm::Function::DLLExportLinkage);
} else if (D->getAttr<WeakAttr>() || D->getAttr<WeakImportAttr>() ||
IsInline)
GV->setLinkage(llvm::Function::WeakLinkage);
}
}
// FIXME: Figure out the relative priority of the attribute,
// -fvisibility, and private_extern.
if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>())
setGlobalVisibility(GV, attr->getVisibility());
// FIXME: else handle -fvisibility
// Prefaced with special LLVM marker to indicate that the name
// should not be munged.
if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>())
GV->setName("\01" + ALA->getLabel());
if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GV->setSection(SA->getName());
// Only add to llvm.used when we see a definition, otherwise we
// might add multiple times or risk the value being replaced by a
// subsequent RAUW.
if (ForDefinition) {
if (D->getAttr<UsedAttr>())
AddUsedGlobal(GV);
}
}
void CodeGenModule::SetFunctionAttributes(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->getAttr<FastCallAttr>())
F->setCallingConv(llvm::CallingConv::X86_FastCall);
if (D->getAttr<StdCallAttr>())
F->setCallingConv(llvm::CallingConv::X86_StdCall);
}
/// SetFunctionAttributesForDefinition - Set function attributes
/// specific to a function definition.
void CodeGenModule::SetFunctionAttributesForDefinition(const Decl *D,
llvm::Function *F) {
if (isa<ObjCMethodDecl>(D)) {
SetGlobalValueAttributes(D, true, false, F, true);
} else {
const FunctionDecl *FD = cast<FunctionDecl>(D);
SetGlobalValueAttributes(FD, FD->getStorageClass() == FunctionDecl::Static,
FD->isInline(), F, true);
}
if (!Features.Exceptions && !Features.ObjCNonFragileABI)
F->addFnAttr(llvm::Attribute::NoUnwind);
if (D->getAttr<AlwaysInlineAttr>())
F->addFnAttr(llvm::Attribute::AlwaysInline);
if (D->getAttr<NoinlineAttr>())
F->addFnAttr(llvm::Attribute::NoInline);
}
void CodeGenModule::SetMethodAttributes(const ObjCMethodDecl *MD,
llvm::Function *F) {
SetFunctionAttributes(MD, getTypes().getFunctionInfo(MD), F);
SetFunctionAttributesForDefinition(MD, F);
}
void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
llvm::Function *F) {
SetFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F);
SetGlobalValueAttributes(FD, FD->getStorageClass() == FunctionDecl::Static,
FD->isInline(), F, false);
}
void CodeGenModule::EmitAliases() {
for (unsigned i = 0, e = Aliases.size(); i != e; ++i) {
const FunctionDecl *D = Aliases[i];
const AliasAttr *AA = D->getAttr<AliasAttr>();
// This is something of a hack, if the FunctionDecl got overridden
// then its attributes will be moved to the new declaration. In
// this case the current decl has no alias attribute, but we will
// eventually see it.
if (!AA)
continue;
const std::string& aliaseeName = AA->getAliasee();
llvm::Function *aliasee = getModule().getFunction(aliaseeName);
if (!aliasee) {
// FIXME: This isn't unsupported, this is just an error, which
// sema should catch, but...
ErrorUnsupported(D, "alias referencing a missing function");
continue;
}
llvm::GlobalValue *GA =
new llvm::GlobalAlias(aliasee->getType(),
llvm::Function::ExternalLinkage,
getMangledName(D), aliasee,
&getModule());
llvm::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
if (Entry) {
// If we created a dummy function for this then replace it.
GA->takeName(Entry);
llvm::Value *Casted =
llvm::ConstantExpr::getBitCast(GA, Entry->getType());
Entry->replaceAllUsesWith(Casted);
Entry->eraseFromParent();
Entry = GA;
}
// Alias should never be internal or inline.
SetGlobalValueAttributes(D, false, false, GA, true);
}
}
void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
assert(!GV->isDeclaration() &&
"Only globals with definition can force usage.");
llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
LLVMUsed.push_back(llvm::ConstantExpr::getBitCast(GV, i8PTy));
}
void CodeGenModule::EmitLLVMUsed() {
// Don't create llvm.used if there is no need.
if (LLVMUsed.empty())
return;
llvm::ArrayType *ATy = llvm::ArrayType::get(LLVMUsed[0]->getType(),
LLVMUsed.size());
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(ATy, false,
llvm::GlobalValue::AppendingLinkage,
llvm::ConstantArray::get(ATy, LLVMUsed),
"llvm.used", &getModule());
GV->setSection("llvm.metadata");
}
void CodeGenModule::EmitDeferred() {
// Emit code for any deferred decl which was used. Since a
// previously unused static decl may become used during the
// generation of code for a static function, iterate until no
// changes are made.
bool Changed;
do {
Changed = false;
for (std::list<const ValueDecl*>::iterator i = DeferredDecls.begin(),
e = DeferredDecls.end(); i != e; ) {
const ValueDecl *D = *i;
// Check if we have used a decl with the same name
// FIXME: The AST should have some sort of aggregate decls or
// global symbol map.
// FIXME: This is missing some important cases. For example, we
// need to check for uses in an alias.
if (!GlobalDeclMap.count(getMangledName(D))) {
++i;
continue;
}
// Emit the definition.
EmitGlobalDefinition(D);
// Erase the used decl from the list.
i = DeferredDecls.erase(i);
// Remember that we made a change.
Changed = true;
}
} while (Changed);
}
/// 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.
llvm::GlobalValue *annoGV =
new llvm::GlobalVariable(anno->getType(), false,
llvm::GlobalValue::InternalLinkage, anno,
GV->getName() + ".str", M);
// translation unit name string, emitted into the llvm.metadata section.
llvm::GlobalValue *unitGV =
new llvm::GlobalVariable(unit->getType(), false,
llvm::GlobalValue::InternalLinkage, unit, ".str", M);
// Create the ConstantStruct that is the global annotion.
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->getAttr<UsedAttr>())
return false;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
// Constructors and destructors should never be deferred.
if (FD->getAttr<ConstructorAttr>() || FD->getAttr<DestructorAttr>())
return false;
if (FD->getStorageClass() != FunctionDecl::Static)
return false;
} else {
const VarDecl *VD = cast<VarDecl>(Global);
assert(VD->isFileVarDecl() && "Invalid decl.");
if (VD->getStorageClass() != VarDecl::Static)
return false;
}
return true;
}
void CodeGenModule::EmitGlobal(const ValueDecl *Global) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
// Aliases are deferred until code for everything else has been
// emitted.
if (FD->getAttr<AliasAttr>()) {
assert(!FD->isThisDeclarationADefinition() &&
"Function alias cannot have a definition!");
Aliases.push_back(FD);
return;
}
// 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.");
// Forward declarations are emitted lazily on first use.
if (!VD->getInit() && VD->hasExternalStorage())
return;
}
// Defer code generation when possible.
if (MayDeferGeneration(Global)) {
DeferredDecls.push_back(Global);
return;
}
// Otherwise emit the definition.
EmitGlobalDefinition(Global);
}
void CodeGenModule::EmitGlobalDefinition(const ValueDecl *D) {
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()");
}
}
llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D) {
assert(D->hasGlobalStorage() && "Not a global variable");
QualType ASTTy = D->getType();
const llvm::Type *Ty = getTypes().ConvertTypeForMem(ASTTy);
const llvm::Type *PTy = llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
if (!Entry) {
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(Ty, false,
llvm::GlobalValue::ExternalLinkage,
0, getMangledName(D), &getModule(),
0, ASTTy.getAddressSpace());
Entry = GV;
// Handle things which are present even on external declarations.
// 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)
setGlobalVisibility(GV, VisibilityAttr::HiddenVisibility);
if (D->getAttr<WeakAttr>() || D->getAttr<WeakImportAttr>())
GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
// Prefaced with special LLVM marker to indicate that the name
// should not be munged.
GV->setName("\01" + ALA->getLabel());
}
}
// Make sure the result is of the correct type.
return llvm::ConstantExpr::getBitCast(Entry, PTy);
}
void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
llvm::Constant *Init = 0;
QualType ASTTy = D->getType();
const llvm::Type *VarTy = getTypes().ConvertTypeForMem(ASTTy);
if (D->getInit() == 0) {
// This is a tentative definition; tentative definitions are
// implicitly initialized with { 0 }
const llvm::Type* InitTy;
if (ASTTy->isIncompleteArrayType()) {
// An incomplete array is normally [ TYPE x 0 ], but we need
// to fix it to [ TYPE x 1 ].
const llvm::ArrayType* ATy = cast<llvm::ArrayType>(VarTy);
InitTy = llvm::ArrayType::get(ATy->getElementType(), 1);
} else {
InitTy = VarTy;
}
Init = llvm::Constant::getNullValue(InitTy);
} else {
Init = EmitConstantExpr(D->getInit());
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::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
llvm::GlobalVariable *GV = cast_or_null<llvm::GlobalVariable>(Entry);
if (!GV) {
GV = new llvm::GlobalVariable(InitType, false,
llvm::GlobalValue::ExternalLinkage,
0, getMangledName(D),
&getModule(), 0, ASTTy.getAddressSpace());
} else if (GV->hasInitializer() && !GV->getInitializer()->isNullValue()) {
// If we already have this global and it has an initializer, then
// we are in the rare situation where we emitted the defining
// declaration of the global and are now being asked to emit a
// definition which would be common. This occurs, for example, in
// the following situation because statics can be emitted out of
// order:
//
// static int x;
// static int *y = &x;
// static int x = 10;
// int **z = &y;
//
// Bail here so we don't blow away the definition. Note that if we
// can't distinguish here if we emitted a definition with a null
// initializer, but this case is safe.
assert(!D->getInit() && "Emitting multiple definitions of a decl!");
return;
} else if (GV->getType() !=
llvm::PointerType::get(InitType, ASTTy.getAddressSpace())) {
// We have a definition after a prototype 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).
//
// FIXME: This also ends up happening if there's a definition followed by
// a tentative definition! (Although Sema rejects that construct
// at the moment.)
// Save the old global
llvm::GlobalVariable *OldGV = GV;
// Make a new global with the correct type
GV = new llvm::GlobalVariable(InitType, false,
llvm::GlobalValue::ExternalLinkage,
0, getMangledName(D),
&getModule(), 0, ASTTy.getAddressSpace());
// Steal the name of the old global
GV->takeName(OldGV);
// Replace all uses of the old global with the new global
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
OldGV->replaceAllUsesWith(NewPtrForOldDecl);
// Erase the old global, since it is no longer used.
OldGV->eraseFromParent();
}
Entry = GV;
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));
if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>())
setGlobalVisibility(GV, attr->getVisibility());
// FIXME: else handle -fvisibility
if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
// Prefaced with special LLVM marker to indicate that the name
// should not be munged.
GV->setName("\01" + ALA->getLabel());
}
// Set the llvm linkage type as appropriate.
if (D->getStorageClass() == VarDecl::Static)
GV->setLinkage(llvm::Function::InternalLinkage);
else if (D->getAttr<DLLImportAttr>())
GV->setLinkage(llvm::Function::DLLImportLinkage);
else if (D->getAttr<DLLExportAttr>())
GV->setLinkage(llvm::Function::DLLExportLinkage);
else if (D->getAttr<WeakAttr>() || D->getAttr<WeakImportAttr>())
GV->setLinkage(llvm::GlobalVariable::WeakLinkage);
else {
// FIXME: This isn't right. This should handle common linkage and other
// stuff.
switch (D->getStorageClass()) {
case VarDecl::Static: assert(0 && "This case handled above");
case VarDecl::Auto:
case VarDecl::Register:
assert(0 && "Can't have auto or register globals");
case VarDecl::None:
if (!D->getInit())
GV->setLinkage(llvm::GlobalVariable::CommonLinkage);
else
GV->setLinkage(llvm::GlobalVariable::ExternalLinkage);
break;
case VarDecl::Extern:
// FIXME: common
break;
case VarDecl::PrivateExtern:
GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
// FIXME: common
break;
}
}
if (const SectionAttr *SA = D->getAttr<SectionAttr>())
GV->setSection(SA->getName());
if (D->getAttr<UsedAttr>())
AddUsedGlobal(GV);
// Emit global variable debug information.
CGDebugInfo *DI = getDebugInfo();
if(DI) {
DI->setLocation(D->getLocation());
DI->EmitGlobalVariable(GV, D);
}
}
llvm::GlobalValue *
CodeGenModule::EmitForwardFunctionDefinition(const FunctionDecl *D,
const llvm::Type *Ty) {
bool DoSetAttributes = true;
if (!Ty) {
Ty = getTypes().ConvertType(D->getType());
if (!isa<llvm::FunctionType>(Ty)) {
// 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.
Ty = llvm::FunctionType::get(llvm::Type::VoidTy,
std::vector<const llvm::Type*>(), false);
DoSetAttributes = false;
}
}
llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty),
llvm::Function::ExternalLinkage,
getMangledName(D),
&getModule());
if (DoSetAttributes)
SetFunctionAttributes(D, F);
return F;
}
llvm::Constant *CodeGenModule::GetAddrOfFunction(const FunctionDecl *D) {
QualType ASTTy = D->getType();
const llvm::Type *Ty = getTypes().ConvertTypeForMem(ASTTy);
const llvm::Type *PTy = llvm::PointerType::get(Ty, ASTTy.getAddressSpace());
// Lookup the entry, lazily creating it if necessary.
llvm::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
if (!Entry)
Entry = EmitForwardFunctionDefinition(D, 0);
return llvm::ConstantExpr::getBitCast(Entry, PTy);
}
void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
const llvm::FunctionType *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 (Ty->isVarArg() && Ty->getNumParams() == 0 && Ty->isVarArg())
Ty = llvm::FunctionType::get(Ty->getReturnType(),
std::vector<const llvm::Type*>(),
false);
llvm::GlobalValue *&Entry = GlobalDeclMap[getMangledName(D)];
if (!Entry) {
Entry = EmitForwardFunctionDefinition(D, Ty);
} else {
// If the types mismatch then we have to rewrite the definition.
if (Entry->getType() != llvm::PointerType::getUnqual(Ty)) {
// Otherwise, we have a definition after a prototype with the
// wrong type. 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.
llvm::GlobalValue *NewFn = EmitForwardFunctionDefinition(D, Ty);
NewFn->takeName(Entry);
// Replace uses of F with the Function we will endow with a body.
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
Entry->replaceAllUsesWith(NewPtrForOldDecl);
// Ok, delete the old function now, which is dead.
assert(Entry->isDeclaration() && "Shouldn't replace non-declaration");
Entry->eraseFromParent();
Entry = NewFn;
}
}
llvm::Function *Fn = cast<llvm::Function>(Entry);
CodeGenFunction(*this).GenerateCode(D, Fn);
SetFunctionAttributesForDefinition(D, Fn);
if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) {
AddGlobalCtor(Fn, CA->getPriority());
} else if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) {
AddGlobalDtor(Fn, DA->getPriority());
}
}
llvm::Function *
CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy,
const std::string &Name) {
llvm::Function *Fn = llvm::Function::Create(FTy,
llvm::Function::ExternalLinkage,
"", &TheModule);
RuntimeGlobals.push_back(std::make_pair(Fn, Name));
return Fn;
}
llvm::GlobalVariable *
CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty,
const std::string &Name) {
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(Ty, /*Constant=*/false,
llvm::GlobalValue::ExternalLinkage,
0, "", &TheModule);
RuntimeGlobals.push_back(std::make_pair(GV, Name));
return GV;
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);
}
/// getBuiltinLibFunction
llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) {
if (BuiltinID > BuiltinFunctions.size())
BuiltinFunctions.resize(BuiltinID);
// Cache looked up functions. Since builtin id #0 is invalid we don't reserve
// a slot for it.
assert(BuiltinID && "Invalid Builtin ID");
llvm::Value *&FunctionSlot = BuiltinFunctions[BuiltinID-1];
if (FunctionSlot)
return FunctionSlot;
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));
// FIXME: This has a serious problem with code like this:
// void abs() {}
// ... __builtin_abs(x);
// The two versions of abs will collide. The fix is for the builtin to win,
// and for the existing one to be turned into a constantexpr cast of the
// builtin. In the case where the existing one is a static function, it
// should just be renamed.
if (llvm::Function *Existing = getModule().getFunction(Name)) {
if (Existing->getFunctionType() == Ty && Existing->hasExternalLinkage())
return FunctionSlot = Existing;
assert(Existing == 0 && "FIXME: Name collision");
}
llvm::GlobalValue *&ExistingFn =
GlobalDeclMap[getContext().Idents.get(Name).getName()];
if (ExistingFn)
return FunctionSlot = llvm::ConstantExpr::getBitCast(ExistingFn, Ty);
// FIXME: param attributes for sext/zext etc.
return FunctionSlot = ExistingFn =
llvm::Function::Create(Ty, llvm::Function::ExternalLinkage, Name,
&getModule());
}
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);
}
}
// We still need to work out the details of handling UTF-16.
// See: <rdr://2996215>
llvm::Constant *CodeGenModule::
GetAddrOfConstantCFString(const std::string &str) {
llvm::StringMapEntry<llvm::Constant *> &Entry =
CFConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]);
if (Entry.getValue())
return Entry.getValue();
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();
// 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,
llvm::ConstantInt::get(Ty, 0x07C8), CFRD, STy);
// String pointer.
CurField = NextField;
NextField = *Field++;
llvm::Constant *C = llvm::ConstantArray::get(str);
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, ".str", &getModule());
appendFieldAndPadding(*this, Fields, CurField, NextField,
llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2),
CFRD, STy);
// String length.
CurField = NextField;
NextField = 0;
Ty = getTypes().ConvertType(getContext().LongTy);
appendFieldAndPadding(*this, Fields, CurField, NextField,
llvm::ConstantInt::get(Ty, str.length()), CFRD, STy);
// The struct.
C = llvm::ConstantStruct::get(STy, Fields);
llvm::GlobalVariable *GV =
new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalVariable::InternalLinkage,
C, "", &getModule());
GV->setSection("__DATA,__cfstring");
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);
llvm::Constant *C = llvm::ConstantArray::get(Str);
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, ".str", &getModule());
return C;
}
/// 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 ? GlobalName : ".str",
&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) {
// Don't share any string literals if writable-strings is turned on.
if (Features.WritableStrings)
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(),
e = D->propimpl_end(); 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(PD->getGetterName()))
CodeGenFunction(*this).GenerateObjCGetter(
const_cast<ObjCImplementationDecl *>(D), PID);
if (!PD->isReadOnly() &&
!D->getInstanceMethod(PD->getSetterName()))
CodeGenFunction(*this).GenerateObjCSetter(
const_cast<ObjCImplementationDecl *>(D), PID);
}
}
}
/// 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::Function:
case Decl::Var:
EmitGlobal(cast<ValueDecl>(D));
break;
case Decl::Namespace:
ErrorUnsupported(D, "namespace");
break;
// Objective-C Decls
// Forward declarations, no (immediate) code generation.
case Decl::ObjCClass:
case Decl::ObjCCategory:
case Decl::ObjCForwardProtocol:
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())
CodeGenFunction(*this).GenerateObjCMethod(OMD);
break;
}
case Decl::ObjCCompatibleAlias:
// compatibility-alias is a directive and has no code gen.
break;
case Decl::LinkageSpec: {
LinkageSpecDecl *LSD = cast<LinkageSpecDecl>(D);
if (LSD->getLanguage() == LinkageSpecDecl::lang_cxx)
ErrorUnsupported(LSD, "linkage spec");
// FIXME: implement C++ linkage, C linkage works mostly by C
// language reuse already.
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");
}
}