Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 1 | //===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file was developed by Chris Lattner and is distributed under |
| 6 | // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This coordinates the per-function state used while generating code. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "CodeGenFunction.h" |
| 15 | #include "CodeGenModule.h" |
| 16 | #include "clang/Basic/TargetInfo.h" |
| 17 | #include "clang/AST/AST.h" |
| 18 | #include "llvm/Constants.h" |
| 19 | #include "llvm/DerivedTypes.h" |
| 20 | #include "llvm/Function.h" |
| 21 | #include "llvm/Analysis/Verifier.h" |
| 22 | using namespace clang; |
| 23 | using namespace CodeGen; |
| 24 | |
| 25 | CodeGenFunction::CodeGenFunction(CodeGenModule &cgm) |
| 26 | : CGM(cgm), Target(CGM.getContext().Target) {} |
| 27 | |
| 28 | ASTContext &CodeGenFunction::getContext() const { |
| 29 | return CGM.getContext(); |
| 30 | } |
| 31 | |
| 32 | |
| 33 | llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) { |
| 34 | llvm::BasicBlock *&BB = LabelMap[S]; |
| 35 | if (BB) return BB; |
| 36 | |
| 37 | // Create, but don't insert, the new block. |
| 38 | return BB = new llvm::BasicBlock(S->getName()); |
| 39 | } |
| 40 | |
| 41 | |
| 42 | const llvm::Type *CodeGenFunction::ConvertType(QualType T) { |
| 43 | return CGM.getTypes().ConvertType(T); |
| 44 | } |
| 45 | |
| 46 | bool CodeGenFunction::hasAggregateLLVMType(QualType T) { |
| 47 | return !T->isRealType() && !T->isPointerType() && !T->isVoidType() && |
| 48 | !T->isVectorType(); |
| 49 | } |
| 50 | |
| 51 | |
| 52 | void CodeGenFunction::GenerateCode(const FunctionDecl *FD) { |
| 53 | LLVMIntTy = ConvertType(getContext().IntTy); |
| 54 | LLVMPointerWidth = Target.getPointerWidth(SourceLocation()); |
| 55 | |
| 56 | CurFn = cast<llvm::Function>(CGM.GetAddrOfGlobalDecl(FD)); |
| 57 | CurFuncDecl = FD; |
| 58 | |
| 59 | // TODO: Set up linkage and many other things. |
| 60 | assert(CurFn->isDeclaration() && "Function already has body?"); |
| 61 | |
| 62 | llvm::BasicBlock *EntryBB = new llvm::BasicBlock("entry", CurFn); |
| 63 | |
| 64 | Builder.SetInsertPoint(EntryBB); |
| 65 | |
| 66 | // Create a marker to make it easy to insert allocas into the entryblock |
| 67 | // later. |
| 68 | llvm::Value *Undef = llvm::UndefValue::get(llvm::Type::Int32Ty); |
| 69 | AllocaInsertPt = Builder.CreateBitCast(Undef,llvm::Type::Int32Ty, "allocapt"); |
| 70 | |
| 71 | // Emit allocs for param decls. Give the LLVM Argument nodes names. |
| 72 | llvm::Function::arg_iterator AI = CurFn->arg_begin(); |
| 73 | |
| 74 | // Name the struct return argument. |
| 75 | if (hasAggregateLLVMType(FD->getResultType())) { |
| 76 | AI->setName("agg.result"); |
| 77 | ++AI; |
| 78 | } |
| 79 | |
| 80 | for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i, ++AI) { |
| 81 | assert(AI != CurFn->arg_end() && "Argument mismatch!"); |
| 82 | EmitParmDecl(*FD->getParamDecl(i), AI); |
| 83 | } |
| 84 | |
| 85 | // Emit the function body. |
| 86 | EmitStmt(FD->getBody()); |
| 87 | |
| 88 | // Emit a return for code that falls off the end. |
| 89 | // FIXME: if this is C++ main, this should return 0. |
| 90 | if (CurFn->getReturnType() == llvm::Type::VoidTy) |
| 91 | Builder.CreateRetVoid(); |
| 92 | else |
| 93 | Builder.CreateRet(llvm::UndefValue::get(CurFn->getReturnType())); |
| 94 | |
| 95 | // Verify that the function is well formed. |
| 96 | assert(!verifyFunction(*CurFn)); |
| 97 | } |
| 98 | |