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//===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===//
//
// 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-function state used while generating code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/AST/AST.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Analysis/Verifier.h"
using namespace llvm;
using namespace clang;
using namespace CodeGen;
CodeGenFunction::CodeGenFunction(CodeGenModule &cgm)
: CGM(cgm), Target(CGM.getContext().Target) {}
llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) {
BasicBlock *&BB = LabelMap[S];
if (BB) return BB;
// Create, but don't insert, the new block.
return BB = new BasicBlock(S->getName());
}
/// ConvertType - Convert the specified type to its LLVM form.
const llvm::Type *CodeGenFunction::ConvertType(QualType T, SourceLocation Loc) {
// FIXME: Cache these, move the CodeGenModule, expand, etc.
const clang::Type &Ty = *T.getCanonicalType();
switch (Ty.getTypeClass()) {
case Type::Builtin: {
switch (cast<BuiltinType>(Ty).getKind()) {
case BuiltinType::Void:
// LLVM void type can only be used as the result of a function call. Just
// map to the same as char.
case BuiltinType::Char:
case BuiltinType::SChar:
case BuiltinType::UChar:
return IntegerType::get(Target.getCharWidth(Loc));
case BuiltinType::Bool:
return IntegerType::get(Target.getBoolWidth(Loc));
case BuiltinType::Short:
case BuiltinType::UShort:
return IntegerType::get(Target.getShortWidth(Loc));
case BuiltinType::Int:
case BuiltinType::UInt:
return IntegerType::get(Target.getIntWidth(Loc));
case BuiltinType::Long:
case BuiltinType::ULong:
return IntegerType::get(Target.getLongWidth(Loc));
case BuiltinType::LongLong:
case BuiltinType::ULongLong:
return IntegerType::get(Target.getLongLongWidth(Loc));
case BuiltinType::Float: return llvm::Type::FloatTy;
case BuiltinType::Double: return llvm::Type::DoubleTy;
case BuiltinType::LongDouble:
case BuiltinType::FloatComplex:
case BuiltinType::DoubleComplex:
case BuiltinType::LongDoubleComplex:
;
}
break;
}
case Type::Pointer:
case Type::Reference:
case Type::Array:
break;
case Type::FunctionNoProto:
case Type::FunctionProto: {
const FunctionType &FP = cast<FunctionType>(Ty);
const llvm::Type *ResultType;
if (FP.getResultType()->isVoidType())
ResultType = llvm::Type::VoidTy; // Result of function uses llvm void.
else
ResultType = ConvertType(FP.getResultType(), Loc);
// FIXME: Convert argument types.
return llvm::FunctionType::get(ResultType,
std::vector<const llvm::Type*>(),
false,
0);
}
case Type::TypeName:
case Type::Tagged:
break;
}
// FIXME: implement.
return OpaqueType::get();
}
void CodeGenFunction::GenerateCode(const FunctionDecl *FD) {
const llvm::FunctionType *Ty =
cast<llvm::FunctionType>(ConvertType(FD->getType(), FD->getLocation()));
CurFuncDecl = FD;
CurFn = new Function(Ty, Function::ExternalLinkage,
FD->getName(), &CGM.getModule());
BasicBlock *EntryBB = new BasicBlock("entry", CurFn);
// TODO: Walk the decls, creating allocas etc.
Builder.SetInsertPoint(EntryBB);
EmitStmt(FD->getBody());
// Emit a return for code that falls off the end.
// FIXME: if this is C++ main, this should return 0.
if (Ty->getReturnType() == llvm::Type::VoidTy)
Builder.CreateRetVoid();
else
Builder.CreateRet(UndefValue::get(Ty->getReturnType()));
// Verify that the function is well formed.
assert(!verifyFunction(*CurFn));
}
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