llvm-project/clang/CodeGen/CodeGenModule.cpp

248 lines
8.8 KiB
C++

//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This coordinates the per-module state used while generating code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Intrinsics.h"
using namespace clang;
using namespace CodeGen;
CodeGenModule::CodeGenModule(ASTContext &C, llvm::Module &M)
: Context(C), TheModule(M), Types(C, M), CFConstantStringClassRef(0) {}
llvm::Constant *CodeGenModule::GetAddrOfGlobalDecl(const ValueDecl *D) {
// See if it is already in the map.
llvm::Constant *&Entry = GlobalDeclMap[D];
if (Entry) return Entry;
QualType ASTTy = cast<ValueDecl>(D)->getType();
const llvm::Type *Ty = getTypes().ConvertType(ASTTy);
if (isa<FunctionDecl>(D)) {
const llvm::FunctionType *FTy = cast<llvm::FunctionType>(Ty);
// FIXME: param attributes for sext/zext etc.
return Entry = new llvm::Function(FTy, llvm::Function::ExternalLinkage,
D->getName(), &getModule());
}
assert(isa<FileVarDecl>(D) && "Unknown global decl!");
return Entry = new llvm::GlobalVariable(Ty, false,
llvm::GlobalValue::ExternalLinkage,
0, D->getName(), &getModule());
}
void CodeGenModule::EmitFunction(const FunctionDecl *FD) {
// If this is not a prototype, emit the body.
if (FD->getBody())
CodeGenFunction(*this).GenerateCode(FD);
}
void CodeGenModule::EmitGlobalVar(const FileVarDecl *D) {
llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalDecl(D));
// If the storage class is external and there is no initializer, just leave it
// as a declaration.
if (D->getStorageClass() == VarDecl::Extern && D->getInit() == 0)
return;
// Otherwise, convert the initializer, or use zero if appropriate.
llvm::Constant *Init = 0;
if (D->getInit() == 0) {
Init = llvm::Constant::getNullValue(GV->getType()->getElementType());
} else if (D->getType()->isIntegerType()) {
llvm::APSInt Value(static_cast<uint32_t>(
getContext().getTypeSize(D->getInit()->getType(), SourceLocation())));
if (D->getInit()->isIntegerConstantExpr(Value, Context))
Init = llvm::ConstantInt::get(Value);
}
if (!Init) {
if (const InitListExpr *ILE = dyn_cast<InitListExpr>(D->getInit())) {
unsigned NumInitElements = ILE->getNumInits();
assert ( ILE->getType()->isArrayType()
&& "FIXME: Only Array initializers are supported");
std::vector<llvm::Constant*> ArrayElts;
const llvm::PointerType *APType = cast<llvm::PointerType>(GV->getType());
const llvm::ArrayType *AType =
cast<llvm::ArrayType>(APType->getElementType());
// Copy initializer elements.
unsigned i = 0;
for (i = 0; i < NumInitElements; ++i) {
assert (ILE->getInit(i)->getType()->isIntegerType()
&& "Only IntegerType global array initializers are supported");
llvm::APSInt
Value(static_cast<uint32_t>
(getContext().getTypeSize(ILE->getInit(i)->getType(),
SourceLocation())));
if (ILE->getInit(i)->isIntegerConstantExpr(Value, Context)) {
llvm::Constant *C = llvm::ConstantInt::get(Value);
ArrayElts.push_back(C);
}
}
// Initialize remaining array elements.
unsigned NumArrayElements = AType->getNumElements();
const llvm::Type *AElemTy = AType->getElementType();
for (; i < NumArrayElements; ++i)
ArrayElts.push_back(llvm::Constant::getNullValue(AElemTy));
Init = llvm::ConstantArray::get(AType, ArrayElts);
} else
assert(Init && "FIXME: Global variable initializers unimp!");
}
GV->setInitializer(Init);
// Set the llvm linkage type as appropriate.
// FIXME: This isn't right. This should handle common linkage and other
// stuff.
switch (D->getStorageClass()) {
case VarDecl::Auto:
case VarDecl::Register:
assert(0 && "Can't have auto or register globals");
case VarDecl::None:
case VarDecl::Extern:
// todo: common
break;
case VarDecl::Static:
GV->setLinkage(llvm::GlobalVariable::InternalLinkage);
break;
}
}
/// EmitGlobalVarDeclarator - Emit all the global vars attached to the specified
/// declarator chain.
void CodeGenModule::EmitGlobalVarDeclarator(const FileVarDecl *D) {
for (; D; D = cast_or_null<FileVarDecl>(D->getNextDeclarator()))
EmitGlobalVar(D);
}
/// getBuiltinLibFunction
llvm::Function *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) {
if (BuiltinFunctions.size() <= BuiltinID)
BuiltinFunctions.resize(BuiltinID);
// Already available?
llvm::Function *&FunctionSlot = BuiltinFunctions[BuiltinID];
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 = new llvm::Function(Ty, llvm::Function::ExternalLinkage,
Name, &getModule());
}
llvm::Function *CodeGenModule::getMemCpyFn() {
if (MemCpyFn) return MemCpyFn;
llvm::Intrinsic::ID IID;
uint64_t Size; unsigned Align;
Context.Target.getPointerInfo(Size, Align, SourceLocation());
switch (Size) {
default: assert(0 && "Unknown ptr width");
case 32: IID = llvm::Intrinsic::memcpy_i32; break;
case 64: IID = llvm::Intrinsic::memcpy_i64; break;
}
return MemCpyFn = llvm::Intrinsic::getDeclaration(&TheModule, IID);
}
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);
C = new llvm::GlobalVariable(C->getType(), true,
llvm::GlobalVariable::InternalLinkage,
C, "", &getModule());
Entry.setValue(C);
return C;
}