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llvm-project/clang/lib/CodeGen/CodeGenModule.cpp
Daniel Dunbar 829e988899 Change CodeGen of global decls to key off of the name (instead of 
having multiple bindings from all the possible decls which
  conceptually map to the same global).

 - This eliminates CodeGen depending on the LLVM module for name
   lookup.

 - This also eliminates the need for ReplaceMapValuesWith (hurrah).

 - This handles lookups for FunctionDecls correctly in the presence of
   aliases, this was previously broken.

 - WIP: Can still clean up & unify variable and function emission.

llvm-svn: 54382
2008-08-05 23:31:02 +00:00

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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
}
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 (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (!getModule().getFunction(FD->getName()))
continue;
} else {
if (!getModule().getNamedGlobal(cast<VarDecl>(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
// 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;
}
/// 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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