зеркало из https://github.com/microsoft/clang-1.git
140 строки
4.5 KiB
C++
140 строки
4.5 KiB
C++
//===--- 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"
|
|
#include "llvm/Support/CFG.h"
|
|
using namespace clang;
|
|
using namespace CodeGen;
|
|
|
|
CodeGenFunction::CodeGenFunction(CodeGenModule &cgm)
|
|
: CGM(cgm), Target(CGM.getContext().Target), SwitchInsn(NULL),
|
|
CaseRangeBlock(NULL) {}
|
|
|
|
ASTContext &CodeGenFunction::getContext() const {
|
|
return CGM.getContext();
|
|
}
|
|
|
|
|
|
llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) {
|
|
llvm::BasicBlock *&BB = LabelMap[S];
|
|
if (BB) return BB;
|
|
|
|
// Create, but don't insert, the new block.
|
|
return BB = new llvm::BasicBlock(S->getName());
|
|
}
|
|
|
|
|
|
const llvm::Type *CodeGenFunction::ConvertType(QualType T) {
|
|
return CGM.getTypes().ConvertType(T);
|
|
}
|
|
|
|
bool CodeGenFunction::hasAggregateLLVMType(QualType T) {
|
|
return !T->isRealType() && !T->isPointerType() && !T->isReferenceType() &&
|
|
!T->isVoidType() && !T->isVectorType() && !T->isFunctionType();
|
|
}
|
|
|
|
|
|
void CodeGenFunction::GenerateCode(const FunctionDecl *FD) {
|
|
LLVMIntTy = ConvertType(getContext().IntTy);
|
|
LLVMPointerWidth = static_cast<unsigned>(
|
|
getContext().getTypeSize(getContext().getPointerType(getContext().VoidTy),
|
|
SourceLocation()));
|
|
|
|
CurFn = cast<llvm::Function>(CGM.GetAddrOfGlobalDecl(FD));
|
|
CurFuncDecl = FD;
|
|
|
|
// TODO: Set up linkage and many other things.
|
|
assert(CurFn->isDeclaration() && "Function already has body?");
|
|
|
|
llvm::BasicBlock *EntryBB = new llvm::BasicBlock("entry", CurFn);
|
|
|
|
Builder.SetInsertPoint(EntryBB);
|
|
|
|
// Create a marker to make it easy to insert allocas into the entryblock
|
|
// later.
|
|
llvm::Value *Undef = llvm::UndefValue::get(llvm::Type::Int32Ty);
|
|
AllocaInsertPt = Builder.CreateBitCast(Undef,llvm::Type::Int32Ty, "allocapt");
|
|
|
|
// Emit allocs for param decls. Give the LLVM Argument nodes names.
|
|
llvm::Function::arg_iterator AI = CurFn->arg_begin();
|
|
|
|
// Name the struct return argument.
|
|
if (hasAggregateLLVMType(FD->getResultType())) {
|
|
AI->setName("agg.result");
|
|
++AI;
|
|
}
|
|
|
|
for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i, ++AI) {
|
|
assert(AI != CurFn->arg_end() && "Argument mismatch!");
|
|
EmitParmDecl(*FD->getParamDecl(i), AI);
|
|
}
|
|
|
|
// Emit the function body.
|
|
EmitStmt(FD->getBody());
|
|
|
|
// Emit a return for code that falls off the end. If insert point
|
|
// is a dummy block with no predecessors then remove the block itself.
|
|
llvm::BasicBlock *BB = Builder.GetInsertBlock();
|
|
if (isDummyBlock(BB))
|
|
BB->eraseFromParent();
|
|
else {
|
|
// FIXME: if this is C++ main, this should return 0.
|
|
if (CurFn->getReturnType() == llvm::Type::VoidTy)
|
|
Builder.CreateRetVoid();
|
|
else
|
|
Builder.CreateRet(llvm::UndefValue::get(CurFn->getReturnType()));
|
|
}
|
|
assert(BreakContinueStack.empty() &&
|
|
"mismatched push/pop in break/continue stack!");
|
|
|
|
// Verify that the function is well formed.
|
|
assert(!verifyFunction(*CurFn));
|
|
}
|
|
|
|
/// isDummyBlock - Return true if BB is an empty basic block
|
|
/// with no predecessors.
|
|
bool CodeGenFunction::isDummyBlock(const llvm::BasicBlock *BB) {
|
|
if (BB->empty() && pred_begin(BB) == pred_end(BB))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/// StartBlock - Start new block named N. If insert block is a dummy block
|
|
/// then reuse it.
|
|
void CodeGenFunction::StartBlock(const char *N) {
|
|
llvm::BasicBlock *BB = Builder.GetInsertBlock();
|
|
if (!isDummyBlock(BB))
|
|
EmitBlock(new llvm::BasicBlock(N));
|
|
else
|
|
BB->setName(N);
|
|
}
|
|
|
|
/// getRecordLayoutInfo - Return record layout info.
|
|
const RecordLayoutInfo *CodeGenFunction::getRecordLayoutInfo(CodeGenTypes &CGT,
|
|
QualType RTy) {
|
|
assert (isa<RecordType>(RTy)
|
|
&& "Unexpected type. RecordType expected here.");
|
|
|
|
const llvm::Type *Ty = ConvertType(RTy);
|
|
assert (Ty && "Unable to find llvm::Type");
|
|
|
|
return CGT.getRecordLayoutInfo(Ty);
|
|
}
|