clang-1/lib/CodeGen/CGCXX.cpp

151 строка
4.8 KiB
C++

//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code dealing with C++ code generation.
//
//===----------------------------------------------------------------------===//
// We might split this into multiple files if it gets too unwieldy
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/ADT/StringExtras.h"
using namespace clang;
using namespace CodeGen;
using llvm::utostr;
// FIXME: Name mangling should be moved to a separate class.
static void mangleDeclContextInternal(const DeclContext *D, std::string &S)
{
// FIXME: Should ObjcMethodDecl have the TranslationUnitDecl as its parent?
assert(!D->getParent() || isa<TranslationUnitDecl>(D->getParent()) &&
"Only one level of decl context mangling is currently supported!");
if (const FunctionDecl* FD = dyn_cast<FunctionDecl>(D)) {
S += utostr(FD->getIdentifier()->getLength());
S += FD->getIdentifier()->getName();
if (FD->param_size() == 0)
S += 'v';
else
assert(0 && "mangling of types not supported yet!");
} else if (const ObjCMethodDecl* MD = dyn_cast<ObjCMethodDecl>(D)) {
// FIXME: This should really use GetNameForMethod from CGObjCMac.
std::string Name;
Name += MD->isInstance() ? '-' : '+';
Name += '[';
Name += MD->getClassInterface()->getName();
Name += ' ';
Name += MD->getSelector().getName();
Name += ']';
S += utostr(Name.length());
S += Name;
} else
assert(0 && "Unsupported decl type!");
}
static void mangleVarDeclInternal(const VarDecl &D, std::string &S)
{
S += 'Z';
mangleDeclContextInternal(D.getDeclContext(), S);
S += 'E';
S += utostr(D.getIdentifier()->getLength());
S += D.getIdentifier()->getName();
}
static std::string mangleVarDecl(const VarDecl& D)
{
std::string S = "_Z";
mangleVarDeclInternal(D, S);
return S;
}
static std::string mangleGuardVariable(const VarDecl& D)
{
std::string S = "_ZGV";
mangleVarDeclInternal(D, S);
return S;
}
llvm::GlobalValue *
CodeGenFunction::GenerateStaticCXXBlockVarDecl(const VarDecl &D)
{
assert(!getContext().getLangOptions().ThreadsafeStatics &&
"thread safe statics are currently not supported!");
const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
// FIXME: If the function is inline, the linkage should be weak.
llvm::GlobalValue::LinkageTypes linkage = llvm::GlobalValue::InternalLinkage;
// Create the guard variable.
llvm::GlobalValue *GuardV =
new llvm::GlobalVariable(llvm::Type::Int64Ty, false,
linkage,
llvm::Constant::getNullValue(llvm::Type::Int64Ty),
mangleGuardVariable(D),
&CGM.getModule());
// FIXME: Address space.
const llvm::Type *PtrTy = llvm::PointerType::get(llvm::Type::Int8Ty, 0);
// Load the first byte of the guard variable.
llvm::Value *V = Builder.CreateLoad(Builder.CreateBitCast(GuardV, PtrTy),
"tmp");
// Compare it against 0.
llvm::Value *nullValue = llvm::Constant::getNullValue(llvm::Type::Int8Ty);
llvm::Value *ICmp = Builder.CreateICmpEQ(V, nullValue , "tobool");
llvm::BasicBlock *InitBlock = llvm::BasicBlock::Create("init");
llvm::BasicBlock *EndBlock = llvm::BasicBlock::Create("initend");
// If the guard variable is 0, jump to the initializer code.
Builder.CreateCondBr(ICmp, InitBlock, EndBlock);
EmitBlock(InitBlock);
llvm::GlobalValue *GV =
new llvm::GlobalVariable(LTy, false,
llvm::GlobalValue::InternalLinkage,
llvm::Constant::getNullValue(LTy),
mangleVarDecl(D),
&CGM.getModule(), 0,
D.getType().getAddressSpace());
const Expr *Init = D.getInit();
if (!hasAggregateLLVMType(Init->getType())) {
llvm::Value *V = EmitScalarExpr(Init);
Builder.CreateStore(V, GV, D.getType().isVolatileQualified());
} else if (Init->getType()->isAnyComplexType()) {
EmitComplexExprIntoAddr(Init, GV, D.getType().isVolatileQualified());
} else {
EmitAggExpr(Init, GV, D.getType().isVolatileQualified());
}
Builder.CreateStore(llvm::ConstantInt::get(llvm::Type::Int8Ty, 1),
Builder.CreateBitCast(GuardV, PtrTy));
EmitBlock(EndBlock);
return GV;
}