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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 "CGDebugInfo.h"
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Intrinsics.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/Verifier.h"
#include <algorithm>
using namespace clang;
using namespace CodeGen;
CodeGenModule::CodeGenModule(ASTContext &C, const LangOptions &LO,
llvm::Module &M, const llvm::TargetData &TD,
Diagnostic &diags, bool GenerateDebugInfo)
: Context(C), Features(LO), TheModule(M), TheTargetData(TD), Diags(diags),
Types(C, M, TD), MemCpyFn(0), MemMoveFn(0), MemSetFn(0),
CFConstantStringClassRef(0) {
//TODO: Make this selectable at runtime
Runtime = CreateObjCRuntime(*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() {
EmitStatics();
llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction();
if (ObjCInitFunction)
AddGlobalCtor(ObjCInitFunction);
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
EmitAnnotations();
// Run the verifier to check that the generated code is consistent.
assert(!verifyModule(TheModule));
}
/// WarnUnsupported - Print out a warning that codegen doesn't support the
/// specified stmt yet.
void CodeGenModule::WarnUnsupported(const Stmt *S, const char *Type) {
unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Warning,
"cannot codegen this %0 yet");
SourceRange Range = S->getSourceRange();
std::string Msg = Type;
getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID,
&Msg, 1, &Range, 1);
}
/// WarnUnsupported - Print out a warning that codegen doesn't support the
/// specified decl yet.
void CodeGenModule::WarnUnsupported(const Decl *D, const char *Type) {
unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Warning,
"cannot codegen this %0 yet");
std::string Msg = Type;
getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID,
&Msg, 1);
}
/// setVisibility - Set the visibility for the given LLVM GlobalValue
/// according to the given clang AST visibility value.
void CodeGenModule::setVisibility(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;
}
}
/// AddGlobalCtor - Add a function to the list that will be called before
/// main() runs.
void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
// TODO: 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) {
// TODO: 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");
}
bool hasAggregateLLVMType(QualType T) {
return !T->isRealType() && !T->isPointerLikeType() &&
!T->isVoidType() && !T->isVectorType() && !T->isFunctionType();
}
void CodeGenModule::SetGlobalValueAttributes(const FunctionDecl *FD,
llvm::GlobalValue *GV) {
// TODO: Set up linkage and many other things. Note, this is a simple
// approximation of what we really want.
if (FD->getStorageClass() == FunctionDecl::Static)
GV->setLinkage(llvm::Function::InternalLinkage);
else if (FD->getAttr<DLLImportAttr>())
GV->setLinkage(llvm::Function::DLLImportLinkage);
else if (FD->getAttr<DLLExportAttr>())
GV->setLinkage(llvm::Function::DLLExportLinkage);
else if (FD->getAttr<WeakAttr>() || FD->isInline())
GV->setLinkage(llvm::Function::WeakLinkage);
if (const VisibilityAttr *attr = FD->getAttr<VisibilityAttr>())
CodeGenModule::setVisibility(GV, attr->getVisibility());
// FIXME: else handle -fvisibility
if (const AsmLabelAttr *ALA = FD->getAttr<AsmLabelAttr>()) {
// Prefaced with special LLVM marker to indicate that the name
// should not be munged.
GV->setName("\01" + ALA->getLabel());
}
}
void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
llvm::Function *F,
const llvm::FunctionType *FTy) {
unsigned FuncAttrs = 0;
if (FD->getAttr<NoThrowAttr>())
FuncAttrs |= llvm::ParamAttr::NoUnwind;
if (FD->getAttr<NoReturnAttr>())
FuncAttrs |= llvm::ParamAttr::NoReturn;
llvm::SmallVector<llvm::ParamAttrsWithIndex, 8> ParamAttrList;
if (FuncAttrs)
ParamAttrList.push_back(llvm::ParamAttrsWithIndex::get(0, FuncAttrs));
// Note that there is parallel code in CodeGenFunction::EmitCallExpr
bool AggregateReturn = hasAggregateLLVMType(FD->getResultType());
if (AggregateReturn)
ParamAttrList.push_back(
llvm::ParamAttrsWithIndex::get(1, llvm::ParamAttr::StructRet));
unsigned increment = AggregateReturn ? 2 : 1;
const FunctionTypeProto* FTP = dyn_cast<FunctionTypeProto>(FD->getType());
if (FTP) {
for (unsigned i = 0; i < FTP->getNumArgs(); i++) {
QualType ParamType = FTP->getArgType(i);
unsigned ParamAttrs = 0;
if (ParamType->isRecordType())
ParamAttrs |= llvm::ParamAttr::ByVal;
if (ParamType->isSignedIntegerType() &&
ParamType->isPromotableIntegerType())
ParamAttrs |= llvm::ParamAttr::SExt;
if (ParamType->isUnsignedIntegerType() &&
ParamType->isPromotableIntegerType())
ParamAttrs |= llvm::ParamAttr::ZExt;
if (ParamAttrs)
ParamAttrList.push_back(llvm::ParamAttrsWithIndex::get(i + increment,
ParamAttrs));
}
}
F->setParamAttrs(llvm::PAListPtr::get(ParamAttrList.begin(),
ParamAttrList.size()));
// Set the appropriate calling convention for the Function.
if (FD->getAttr<FastCallAttr>())
F->setCallingConv(llvm::CallingConv::Fast);
SetGlobalValueAttributes(FD, F);
}
void CodeGenModule::EmitObjCMethod(const ObjCMethodDecl *OMD) {
// If this is not a prototype, emit the body.
if (OMD->getBody())
CodeGenFunction(*this).GenerateObjCMethod(OMD);
}
void CodeGenModule::EmitObjCProtocolImplementation(const ObjCProtocolDecl *PD){
llvm::SmallVector<std::string, 16> Protocols;
for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(),
E = PD->protocol_end(); PI != E; ++PI)
Protocols.push_back((*PI)->getName());
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(),
E = PD->instmeth_end(); iter != E; iter++) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(*iter, TypeStr);
InstanceMethodNames.push_back(
GetAddrOfConstantString((*iter)->getSelector().getName()));
InstanceMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
// Collect information about class methods:
llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (ObjCProtocolDecl::classmeth_iterator iter = PD->classmeth_begin(),
endIter = PD->classmeth_end() ; iter != endIter ; iter++) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
ClassMethodNames.push_back(
GetAddrOfConstantString((*iter)->getSelector().getName()));
ClassMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
Runtime->GenerateProtocol(PD->getName(), Protocols, InstanceMethodNames,
InstanceMethodTypes, ClassMethodNames, ClassMethodTypes);
}
void CodeGenModule::EmitObjCCategoryImpl(const ObjCCategoryImplDecl *OCD) {
// Collect information about instance methods
llvm::SmallVector<Selector, 16> InstanceMethodSels;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (ObjCCategoryDecl::instmeth_iterator iter = OCD->instmeth_begin(),
endIter = OCD->instmeth_end() ; iter != endIter ; iter++) {
InstanceMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(*iter,TypeStr);
InstanceMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
// Collect information about class methods
llvm::SmallVector<Selector, 16> ClassMethodSels;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (ObjCCategoryDecl::classmeth_iterator iter = OCD->classmeth_begin(),
endIter = OCD->classmeth_end() ; iter != endIter ; iter++) {
ClassMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(*iter,TypeStr);
ClassMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
// Collect the names of referenced protocols
llvm::SmallVector<std::string, 16> Protocols;
const ObjCInterfaceDecl *ClassDecl = OCD->getClassInterface();
const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols();
for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
E = Protos.end(); I != E; ++I)
Protocols.push_back((*I)->getName());
// Generate the category
Runtime->GenerateCategory(OCD->getClassInterface()->getName(),
OCD->getName(), InstanceMethodSels, InstanceMethodTypes,
ClassMethodSels, ClassMethodTypes, Protocols);
}
void CodeGenModule::EmitObjCClassImplementation(
const ObjCImplementationDecl *OID) {
// Get the superclass name.
const ObjCInterfaceDecl * SCDecl = OID->getClassInterface()->getSuperClass();
const char * SCName = NULL;
if (SCDecl) {
SCName = SCDecl->getName();
}
// Get the class name
ObjCInterfaceDecl * ClassDecl = (ObjCInterfaceDecl*)OID->getClassInterface();
const char * ClassName = ClassDecl->getName();
// Get the size of instances. For runtimes that support late-bound instances
// this should probably be something different (size just of instance
// varaibles in this class, not superclasses?).
int instanceSize = 0;
const llvm::Type *ObjTy;
if (!Runtime->LateBoundIVars()) {
ObjTy = getTypes().ConvertType(Context.getObjCInterfaceType(ClassDecl));
instanceSize = TheTargetData.getABITypeSize(ObjTy);
}
// Collect information about instance variables.
llvm::SmallVector<llvm::Constant*, 16> IvarNames;
llvm::SmallVector<llvm::Constant*, 16> IvarTypes;
llvm::SmallVector<llvm::Constant*, 16> IvarOffsets;
const llvm::StructLayout *Layout =
TheTargetData.getStructLayout(cast<llvm::StructType>(ObjTy));
ObjTy = llvm::PointerType::getUnqual(ObjTy);
for (ObjCInterfaceDecl::ivar_iterator iter = ClassDecl->ivar_begin(),
endIter = ClassDecl->ivar_end() ; iter != endIter ; iter++) {
// Store the name
IvarNames.push_back(GetAddrOfConstantString((*iter)->getName()));
// Get the type encoding for this ivar
std::string TypeStr;
llvm::SmallVector<const RecordType *, 8> EncodingRecordTypes;
Context.getObjCEncodingForType((*iter)->getType(), TypeStr,
EncodingRecordTypes);
IvarTypes.push_back(GetAddrOfConstantString(TypeStr));
// Get the offset
int offset =
(int)Layout->getElementOffset(getTypes().getLLVMFieldNo(*iter));
IvarOffsets.push_back(
llvm::ConstantInt::get(llvm::Type::Int32Ty, offset));
}
// Collect information about instance methods
llvm::SmallVector<Selector, 16> InstanceMethodSels;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (ObjCImplementationDecl::instmeth_iterator iter = OID->instmeth_begin(),
endIter = OID->instmeth_end() ; iter != endIter ; iter++) {
InstanceMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
InstanceMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
// Collect information about class methods
llvm::SmallVector<Selector, 16> ClassMethodSels;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (ObjCImplementationDecl::classmeth_iterator iter = OID->classmeth_begin(),
endIter = OID->classmeth_end() ; iter != endIter ; iter++) {
ClassMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
ClassMethodTypes.push_back(GetAddrOfConstantString(TypeStr));
}
// Collect the names of referenced protocols
llvm::SmallVector<std::string, 16> Protocols;
const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols();
for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
E = Protos.end(); I != E; ++I)
Protocols.push_back((*I)->getName());
// Generate the category
Runtime->GenerateClass(ClassName, SCName, instanceSize, IvarNames, IvarTypes,
IvarOffsets, InstanceMethodSels, InstanceMethodTypes,
ClassMethodSels, ClassMethodTypes, Protocols);
}
void CodeGenModule::EmitStatics() {
// Emit code for each used static decl encountered. 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 (unsigned i = 0, e = StaticDecls.size(); i != e; ++i) {
const ValueDecl *D = StaticDecls[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.
if (!GlobalDeclMap.count(D->getName()))
continue;
// Emit the definition.
EmitGlobalDefinition(D);
// Erase the used decl from the list.
StaticDecls[i] = StaticDecls.back();
StaticDecls.pop_back();
--i;
--e;
// 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);
}
void CodeGenModule::EmitGlobal(const ValueDecl *Global) {
bool isDef, isStatic;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
isDef = (FD->isThisDeclarationADefinition() ||
FD->getAttr<AliasAttr>());
isStatic = FD->getStorageClass() == FunctionDecl::Static;
} else if (const VarDecl *VD = cast<VarDecl>(Global)) {
assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
isDef = !(VD->getStorageClass() == VarDecl::Extern && VD->getInit() == 0);
isStatic = VD->getStorageClass() == VarDecl::Static;
} else {
assert(0 && "Invalid argument to EmitGlobal");
return;
}
// Forward declarations are emitted lazily on first use.
if (!isDef)
return;
// If the global is a static, defer code generation until later so
// we can easily omit unused statics.
if (isStatic) {
StaticDecls.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[D->getName()];
if (!Entry)
Entry = new llvm::GlobalVariable(Ty, false,
llvm::GlobalValue::ExternalLinkage,
0, D->getName(), &getModule(), 0,
ASTTy.getAddressSpace());
// 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());
}
const llvm::Type* InitType = Init->getType();
llvm::GlobalValue *&Entry = GlobalDeclMap[D->getName()];
llvm::GlobalVariable *GV = cast_or_null<llvm::GlobalVariable>(Entry);
if (!GV) {
GV = new llvm::GlobalVariable(InitType, false,
llvm::GlobalValue::ExternalLinkage,
0, D->getName(), &getModule(), 0,
ASTTy.getAddressSpace());
} 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, D->getName(), &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.getLogicalLineNumber(D->getLocation())));
}
GV->setInitializer(Init);
// FIXME: This is silly; getTypeAlign should just work for incomplete arrays
unsigned Align;
if (const IncompleteArrayType* IAT =
Context.getAsIncompleteArrayType(D->getType()))
Align = Context.getTypeAlign(IAT->getElementType());
else
Align = Context.getTypeAlign(D->getType());
if (const AlignedAttr* AA = D->getAttr<AlignedAttr>()) {
Align = std::max(Align, AA->getAlignment());
}
GV->setAlignment(Align / 8);
if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>())
setVisibility(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>())
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);
break;
case VarDecl::Extern:
case VarDecl::PrivateExtern:
// todo: common
break;
}
}
// Emit global variable debug information.
CGDebugInfo *DI = getDebugInfo();
if(DI) {
if(D->getLocation().isValid())
DI->setLocation(D->getLocation());
DI->EmitGlobalVariable(GV, D);
}
}
llvm::GlobalValue *
CodeGenModule::EmitForwardFunctionDefinition(const FunctionDecl *D) {
// FIXME: param attributes for sext/zext etc.
if (const AliasAttr *AA = D->getAttr<AliasAttr>()) {
assert(!D->getBody() && "Unexpected alias attr on function with body.");
const std::string& aliaseeName = AA->getAliasee();
llvm::Function *aliasee = getModule().getFunction(aliaseeName);
llvm::GlobalValue *alias = new llvm::GlobalAlias(aliasee->getType(),
llvm::Function::ExternalLinkage,
D->getName(),
aliasee,
&getModule());
SetGlobalValueAttributes(D, alias);
return alias;
} else {
const llvm::Type *Ty = getTypes().ConvertType(D->getType());
const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
llvm::Function *F = llvm::Function::Create(FTy,
llvm::Function::ExternalLinkage,
D->getName(), &getModule());
SetFunctionAttributes(D, F, FTy);
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[D->getName()];
if (!Entry)
Entry = EmitForwardFunctionDefinition(D);
return llvm::ConstantExpr::getBitCast(Entry, PTy);
}
void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
llvm::GlobalValue *&Entry = GlobalDeclMap[D->getName()];
if (!Entry) {
Entry = EmitForwardFunctionDefinition(D);
} else {
// If the types mismatch then we have to rewrite the definition.
const llvm::Type *Ty = getTypes().ConvertType(D->getType());
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);
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.
// FIXME: Add GlobalValue->eraseFromParent().
assert(Entry->isDeclaration() && "Shouldn't replace non-declaration");
if (llvm::Function *F = dyn_cast<llvm::Function>(Entry)) {
F->eraseFromParent();
} else if (llvm::GlobalAlias *GA = dyn_cast<llvm::GlobalAlias>(Entry)) {
GA->eraseFromParent();
} else {
assert(0 && "Invalid global variable type.");
}
Entry = NewFn;
}
}
if (D->getAttr<AliasAttr>()) {
;
} else {
llvm::Function *Fn = cast<llvm::Function>(Entry);
CodeGenFunction(*this).GenerateCode(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());
}
}
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
// Make sure that this type is translated.
Types.UpdateCompletedType(TD);
}
/// getBuiltinLibFunction
llvm::Function *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::Function *&FunctionSlot = BuiltinFunctions[BuiltinID-1];
if (FunctionSlot)
return FunctionSlot;
assert(Context.BuiltinInfo.isLibFunction(BuiltinID) && "isn't a lib fn");
// Get the name, skip over the __builtin_ prefix.
const char *Name = Context.BuiltinInfo.GetName(BuiltinID)+10;
// Get the type for the builtin.
QualType Type = Context.BuiltinInfo.GetBuiltinType(BuiltinID, Context);
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");
}
// FIXME: param attributes for sext/zext etc.
return FunctionSlot =
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;
llvm::Intrinsic::ID IID;
switch (Context.Target.getPointerWidth(0)) {
default: assert(0 && "Unknown ptr width");
case 32: IID = llvm::Intrinsic::memcpy_i32; break;
case 64: IID = llvm::Intrinsic::memcpy_i64; break;
}
return MemCpyFn = getIntrinsic(IID);
}
llvm::Function *CodeGenModule::getMemMoveFn() {
if (MemMoveFn) return MemMoveFn;
llvm::Intrinsic::ID IID;
switch (Context.Target.getPointerWidth(0)) {
default: assert(0 && "Unknown ptr width");
case 32: IID = llvm::Intrinsic::memmove_i32; break;
case 64: IID = llvm::Intrinsic::memmove_i64; break;
}
return MemMoveFn = getIntrinsic(IID);
}
llvm::Function *CodeGenModule::getMemSetFn() {
if (MemSetFn) return MemSetFn;
llvm::Intrinsic::ID IID;
switch (Context.Target.getPointerWidth(0)) {
default: assert(0 && "Unknown ptr width");
case 32: IID = llvm::Intrinsic::memset_i32; break;
case 64: IID = llvm::Intrinsic::memset_i64; break;
}
return MemSetFn = getIntrinsic(IID);
}
// FIXME: This needs moving into an Apple Objective-C runtime class
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();
std::vector<llvm::Constant*> Fields;
if (!CFConstantStringClassRef) {
const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
Ty = llvm::ArrayType::get(Ty, 0);
CFConstantStringClassRef =
new llvm::GlobalVariable(Ty, false,
llvm::GlobalVariable::ExternalLinkage, 0,
"__CFConstantStringClassReference",
&getModule());
}
// Class pointer.
llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty);
llvm::Constant *Zeros[] = { Zero, Zero };
llvm::Constant *C =
llvm::ConstantExpr::getGetElementPtr(CFConstantStringClassRef, Zeros, 2);
Fields.push_back(C);
// Flags.
const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
Fields.push_back(llvm::ConstantInt::get(Ty, 1992));
// String pointer.
C = llvm::ConstantArray::get(str);
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalValue::InternalLinkage,
C, ".str", &getModule());
C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2);
Fields.push_back(C);
// String length.
Ty = getTypes().ConvertType(getContext().LongTy);
Fields.push_back(llvm::ConstantInt::get(Ty, str.length()));
// The struct.
Ty = getTypes().ConvertType(getContext().getCFConstantStringType());
C = llvm::ConstantStruct::get(cast<llvm::StructType>(Ty), 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) {
assert(!E->isWide() && "FIXME: Wide strings not supported yet!");
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
// FIXME: What about wchar_t strings?
std::string Str(StrData, StrData+Len);
uint64_t RealLen = CAT->getSize().getZExtValue();
Str.resize(RealLen, '\0');
return Str;
}
/// GenerateWritableString -- Creates storage for a string literal.
static llvm::Constant *GenerateStringLiteral(const std::string &str,
bool constant,
CodeGenModule &CGM) {
// Create Constant for this string literal
llvm::Constant *C = llvm::ConstantArray::get(str);
// Create a global variable for this string
C = new llvm::GlobalVariable(C->getType(), constant,
llvm::GlobalValue::InternalLinkage,
C, ".str", &CGM.getModule());
return C;
}
/// CodeGenModule::GetAddrOfConstantString -- returns a pointer to the character
/// array containing the literal. The result is pointer to array type.
llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str) {
// Don't share any string literals if writable-strings is turned on.
if (Features.WritableStrings)
return GenerateStringLiteral(str, false, *this);
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);
Entry.setValue(C);
return C;
}
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