| //===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file 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 "CGDebugInfo.h" |
| #include "CGException.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/AST/APValue.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "clang/Frontend/CodeGenOptions.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Intrinsics.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| CodeGenFunction::CodeGenFunction(CodeGenModule &cgm) |
| : BlockFunction(cgm, *this, Builder), CGM(cgm), |
| Target(CGM.getContext().Target), |
| Builder(cgm.getModule().getContext()), |
| ExceptionSlot(0), DebugInfo(0), IndirectBranch(0), |
| SwitchInsn(0), CaseRangeBlock(0), InvokeDest(0), |
| DidCallStackSave(false), UnreachableBlock(0), |
| CXXThisDecl(0), CXXThisValue(0), CXXVTTDecl(0), CXXVTTValue(0), |
| ConditionalBranchLevel(0), TerminateLandingPad(0), TerminateHandler(0), |
| TrapBB(0) { |
| |
| // Get some frequently used types. |
| LLVMPointerWidth = Target.getPointerWidth(0); |
| llvm::LLVMContext &LLVMContext = CGM.getLLVMContext(); |
| IntPtrTy = llvm::IntegerType::get(LLVMContext, LLVMPointerWidth); |
| Int32Ty = llvm::Type::getInt32Ty(LLVMContext); |
| Int64Ty = llvm::Type::getInt64Ty(LLVMContext); |
| |
| Exceptions = getContext().getLangOptions().Exceptions; |
| CatchUndefined = getContext().getLangOptions().CatchUndefined; |
| CGM.getMangleContext().startNewFunction(); |
| } |
| |
| ASTContext &CodeGenFunction::getContext() const { |
| return CGM.getContext(); |
| } |
| |
| |
| llvm::Value *CodeGenFunction::GetAddrOfLocalVar(const VarDecl *VD) { |
| llvm::Value *Res = LocalDeclMap[VD]; |
| assert(Res && "Invalid argument to GetAddrOfLocalVar(), no decl!"); |
| return Res; |
| } |
| |
| llvm::Constant * |
| CodeGenFunction::GetAddrOfStaticLocalVar(const VarDecl *BVD) { |
| return cast<llvm::Constant>(GetAddrOfLocalVar(BVD)); |
| } |
| |
| const llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) { |
| return CGM.getTypes().ConvertTypeForMem(T); |
| } |
| |
| const llvm::Type *CodeGenFunction::ConvertType(QualType T) { |
| return CGM.getTypes().ConvertType(T); |
| } |
| |
| bool CodeGenFunction::hasAggregateLLVMType(QualType T) { |
| return T->isRecordType() || T->isArrayType() || T->isAnyComplexType() || |
| T->isMemberFunctionPointerType(); |
| } |
| |
| void CodeGenFunction::EmitReturnBlock() { |
| // For cleanliness, we try to avoid emitting the return block for |
| // simple cases. |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| if (CurBB) { |
| assert(!CurBB->getTerminator() && "Unexpected terminated block."); |
| |
| // We have a valid insert point, reuse it if it is empty or there are no |
| // explicit jumps to the return block. |
| if (CurBB->empty() || ReturnBlock.Block->use_empty()) { |
| ReturnBlock.Block->replaceAllUsesWith(CurBB); |
| delete ReturnBlock.Block; |
| } else |
| EmitBlock(ReturnBlock.Block); |
| return; |
| } |
| |
| // Otherwise, if the return block is the target of a single direct |
| // branch then we can just put the code in that block instead. This |
| // cleans up functions which started with a unified return block. |
| if (ReturnBlock.Block->hasOneUse()) { |
| llvm::BranchInst *BI = |
| dyn_cast<llvm::BranchInst>(*ReturnBlock.Block->use_begin()); |
| if (BI && BI->isUnconditional() && |
| BI->getSuccessor(0) == ReturnBlock.Block) { |
| // Reset insertion point and delete the branch. |
| Builder.SetInsertPoint(BI->getParent()); |
| BI->eraseFromParent(); |
| delete ReturnBlock.Block; |
| return; |
| } |
| } |
| |
| // FIXME: We are at an unreachable point, there is no reason to emit the block |
| // unless it has uses. However, we still need a place to put the debug |
| // region.end for now. |
| |
| EmitBlock(ReturnBlock.Block); |
| } |
| |
| static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) { |
| if (!BB) return; |
| if (!BB->use_empty()) |
| return CGF.CurFn->getBasicBlockList().push_back(BB); |
| delete BB; |
| } |
| |
| void CodeGenFunction::FinishFunction(SourceLocation EndLoc) { |
| assert(BreakContinueStack.empty() && |
| "mismatched push/pop in break/continue stack!"); |
| |
| // Emit function epilog (to return). |
| EmitReturnBlock(); |
| |
| EmitFunctionInstrumentation("__cyg_profile_func_exit"); |
| |
| // Emit debug descriptor for function end. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| DI->setLocation(EndLoc); |
| DI->EmitRegionEnd(Builder); |
| } |
| |
| EmitFunctionEpilog(*CurFnInfo); |
| EmitEndEHSpec(CurCodeDecl); |
| |
| assert(EHStack.empty() && |
| "did not remove all scopes from cleanup stack!"); |
| |
| // If someone did an indirect goto, emit the indirect goto block at the end of |
| // the function. |
| if (IndirectBranch) { |
| EmitBlock(IndirectBranch->getParent()); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // Remove the AllocaInsertPt instruction, which is just a convenience for us. |
| llvm::Instruction *Ptr = AllocaInsertPt; |
| AllocaInsertPt = 0; |
| Ptr->eraseFromParent(); |
| |
| // If someone took the address of a label but never did an indirect goto, we |
| // made a zero entry PHI node, which is illegal, zap it now. |
| if (IndirectBranch) { |
| llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress()); |
| if (PN->getNumIncomingValues() == 0) { |
| PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType())); |
| PN->eraseFromParent(); |
| } |
| } |
| |
| EmitIfUsed(*this, TerminateLandingPad); |
| EmitIfUsed(*this, TerminateHandler); |
| EmitIfUsed(*this, UnreachableBlock); |
| |
| if (CGM.getCodeGenOpts().EmitDeclMetadata) |
| EmitDeclMetadata(); |
| } |
| |
| /// ShouldInstrumentFunction - Return true if the current function should be |
| /// instrumented with __cyg_profile_func_* calls |
| bool CodeGenFunction::ShouldInstrumentFunction() { |
| if (!CGM.getCodeGenOpts().InstrumentFunctions) |
| return false; |
| if (CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>()) |
| return false; |
| return true; |
| } |
| |
| /// EmitFunctionInstrumentation - Emit LLVM code to call the specified |
| /// instrumentation function with the current function and the call site, if |
| /// function instrumentation is enabled. |
| void CodeGenFunction::EmitFunctionInstrumentation(const char *Fn) { |
| if (!ShouldInstrumentFunction()) |
| return; |
| |
| const llvm::PointerType *PointerTy; |
| const llvm::FunctionType *FunctionTy; |
| std::vector<const llvm::Type*> ProfileFuncArgs; |
| |
| // void __cyg_profile_func_{enter,exit} (void *this_fn, void *call_site); |
| PointerTy = llvm::Type::getInt8PtrTy(VMContext); |
| ProfileFuncArgs.push_back(PointerTy); |
| ProfileFuncArgs.push_back(PointerTy); |
| FunctionTy = llvm::FunctionType::get( |
| llvm::Type::getVoidTy(VMContext), |
| ProfileFuncArgs, false); |
| |
| llvm::Constant *F = CGM.CreateRuntimeFunction(FunctionTy, Fn); |
| llvm::CallInst *CallSite = Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::returnaddress, 0, 0), |
| llvm::ConstantInt::get(Int32Ty, 0), |
| "callsite"); |
| |
| Builder.CreateCall2(F, |
| llvm::ConstantExpr::getBitCast(CurFn, PointerTy), |
| CallSite); |
| } |
| |
| void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy, |
| llvm::Function *Fn, |
| const FunctionArgList &Args, |
| SourceLocation StartLoc) { |
| const Decl *D = GD.getDecl(); |
| |
| DidCallStackSave = false; |
| CurCodeDecl = CurFuncDecl = D; |
| FnRetTy = RetTy; |
| CurFn = Fn; |
| assert(CurFn->isDeclaration() && "Function already has body?"); |
| |
| // Pass inline keyword to optimizer if it appears explicitly on any |
| // declaration. |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(), |
| RE = FD->redecls_end(); RI != RE; ++RI) |
| if (RI->isInlineSpecified()) { |
| Fn->addFnAttr(llvm::Attribute::InlineHint); |
| break; |
| } |
| |
| llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn); |
| |
| // Create a marker to make it easy to insert allocas into the entryblock |
| // later. Don't create this with the builder, because we don't want it |
| // folded. |
| llvm::Value *Undef = llvm::UndefValue::get(Int32Ty); |
| AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB); |
| if (Builder.isNamePreserving()) |
| AllocaInsertPt->setName("allocapt"); |
| |
| ReturnBlock = getJumpDestInCurrentScope("return"); |
| |
| Builder.SetInsertPoint(EntryBB); |
| |
| QualType FnType = getContext().getFunctionType(RetTy, 0, 0, false, 0, |
| false, false, 0, 0, |
| /*FIXME?*/ |
| FunctionType::ExtInfo()); |
| |
| // Emit subprogram debug descriptor. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| DI->setLocation(StartLoc); |
| DI->EmitFunctionStart(GD, FnType, CurFn, Builder); |
| } |
| |
| EmitFunctionInstrumentation("__cyg_profile_func_enter"); |
| |
| // FIXME: Leaked. |
| // CC info is ignored, hopefully? |
| CurFnInfo = &CGM.getTypes().getFunctionInfo(FnRetTy, Args, |
| FunctionType::ExtInfo()); |
| |
| if (RetTy->isVoidType()) { |
| // Void type; nothing to return. |
| ReturnValue = 0; |
| } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect && |
| hasAggregateLLVMType(CurFnInfo->getReturnType())) { |
| // Indirect aggregate return; emit returned value directly into sret slot. |
| // This reduces code size, and affects correctness in C++. |
| ReturnValue = CurFn->arg_begin(); |
| } else { |
| ReturnValue = CreateIRTemp(RetTy, "retval"); |
| } |
| |
| EmitStartEHSpec(CurCodeDecl); |
| EmitFunctionProlog(*CurFnInfo, CurFn, Args); |
| |
| if (CXXThisDecl) |
| CXXThisValue = Builder.CreateLoad(LocalDeclMap[CXXThisDecl], "this"); |
| if (CXXVTTDecl) |
| CXXVTTValue = Builder.CreateLoad(LocalDeclMap[CXXVTTDecl], "vtt"); |
| |
| // If any of the arguments have a variably modified type, make sure to |
| // emit the type size. |
| for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); |
| i != e; ++i) { |
| QualType Ty = i->second; |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVLASize(Ty); |
| } |
| } |
| |
| void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args) { |
| const FunctionDecl *FD = cast<FunctionDecl>(CurGD.getDecl()); |
| assert(FD->getBody()); |
| EmitStmt(FD->getBody()); |
| } |
| |
| void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn) { |
| const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); |
| |
| // Check if we should generate debug info for this function. |
| if (CGM.getDebugInfo() && !FD->hasAttr<NoDebugAttr>()) |
| DebugInfo = CGM.getDebugInfo(); |
| |
| FunctionArgList Args; |
| |
| CurGD = GD; |
| if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { |
| if (MD->isInstance()) { |
| // Create the implicit 'this' decl. |
| // FIXME: I'm not entirely sure I like using a fake decl just for code |
| // generation. Maybe we can come up with a better way? |
| CXXThisDecl = ImplicitParamDecl::Create(getContext(), 0, |
| FD->getLocation(), |
| &getContext().Idents.get("this"), |
| MD->getThisType(getContext())); |
| Args.push_back(std::make_pair(CXXThisDecl, CXXThisDecl->getType())); |
| |
| // Check if we need a VTT parameter as well. |
| if (CodeGenVTables::needsVTTParameter(GD)) { |
| // FIXME: The comment about using a fake decl above applies here too. |
| QualType T = getContext().getPointerType(getContext().VoidPtrTy); |
| CXXVTTDecl = |
| ImplicitParamDecl::Create(getContext(), 0, FD->getLocation(), |
| &getContext().Idents.get("vtt"), T); |
| Args.push_back(std::make_pair(CXXVTTDecl, CXXVTTDecl->getType())); |
| } |
| } |
| } |
| |
| if (FD->getNumParams()) { |
| const FunctionProtoType* FProto = FD->getType()->getAs<FunctionProtoType>(); |
| assert(FProto && "Function def must have prototype!"); |
| |
| for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) |
| Args.push_back(std::make_pair(FD->getParamDecl(i), |
| FProto->getArgType(i))); |
| } |
| |
| SourceRange BodyRange; |
| if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange(); |
| |
| // Emit the standard function prologue. |
| StartFunction(GD, FD->getResultType(), Fn, Args, BodyRange.getBegin()); |
| |
| // Generate the body of the function. |
| if (isa<CXXDestructorDecl>(FD)) |
| EmitDestructorBody(Args); |
| else if (isa<CXXConstructorDecl>(FD)) |
| EmitConstructorBody(Args); |
| else |
| EmitFunctionBody(Args); |
| |
| // Emit the standard function epilogue. |
| FinishFunction(BodyRange.getEnd()); |
| |
| // Destroy the 'this' declaration. |
| if (CXXThisDecl) |
| CXXThisDecl->Destroy(getContext()); |
| |
| // Destroy the VTT declaration. |
| if (CXXVTTDecl) |
| CXXVTTDecl->Destroy(getContext()); |
| } |
| |
| /// ContainsLabel - Return true if the statement contains a label in it. If |
| /// this statement is not executed normally, it not containing a label means |
| /// that we can just remove the code. |
| bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) { |
| // Null statement, not a label! |
| if (S == 0) return false; |
| |
| // If this is a label, we have to emit the code, consider something like: |
| // if (0) { ... foo: bar(); } goto foo; |
| if (isa<LabelStmt>(S)) |
| return true; |
| |
| // If this is a case/default statement, and we haven't seen a switch, we have |
| // to emit the code. |
| if (isa<SwitchCase>(S) && !IgnoreCaseStmts) |
| return true; |
| |
| // If this is a switch statement, we want to ignore cases below it. |
| if (isa<SwitchStmt>(S)) |
| IgnoreCaseStmts = true; |
| |
| // Scan subexpressions for verboten labels. |
| for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); |
| I != E; ++I) |
| if (ContainsLabel(*I, IgnoreCaseStmts)) |
| return true; |
| |
| return false; |
| } |
| |
| |
| /// ConstantFoldsToSimpleInteger - If the sepcified expression does not fold to |
| /// a constant, or if it does but contains a label, return 0. If it constant |
| /// folds to 'true' and does not contain a label, return 1, if it constant folds |
| /// to 'false' and does not contain a label, return -1. |
| int CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond) { |
| // FIXME: Rename and handle conversion of other evaluatable things |
| // to bool. |
| Expr::EvalResult Result; |
| if (!Cond->Evaluate(Result, getContext()) || !Result.Val.isInt() || |
| Result.HasSideEffects) |
| return 0; // Not foldable, not integer or not fully evaluatable. |
| |
| if (CodeGenFunction::ContainsLabel(Cond)) |
| return 0; // Contains a label. |
| |
| return Result.Val.getInt().getBoolValue() ? 1 : -1; |
| } |
| |
| |
| /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if |
| /// statement) to the specified blocks. Based on the condition, this might try |
| /// to simplify the codegen of the conditional based on the branch. |
| /// |
| void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond, |
| llvm::BasicBlock *TrueBlock, |
| llvm::BasicBlock *FalseBlock) { |
| if (const ParenExpr *PE = dyn_cast<ParenExpr>(Cond)) |
| return EmitBranchOnBoolExpr(PE->getSubExpr(), TrueBlock, FalseBlock); |
| |
| if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) { |
| // Handle X && Y in a condition. |
| if (CondBOp->getOpcode() == BinaryOperator::LAnd) { |
| // If we have "1 && X", simplify the code. "0 && X" would have constant |
| // folded if the case was simple enough. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == 1) { |
| // br(1 && X) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| } |
| |
| // If we have "X && 1", simplify the code to use an uncond branch. |
| // "X && 0" would have been constant folded to 0. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == 1) { |
| // br(X && 1) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is false, we |
| // want to jump to the FalseBlock. |
| llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true"); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock); |
| EmitBlock(LHSTrue); |
| |
| // Any temporaries created here are conditional. |
| BeginConditionalBranch(); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| EndConditionalBranch(); |
| |
| return; |
| } else if (CondBOp->getOpcode() == BinaryOperator::LOr) { |
| // If we have "0 || X", simplify the code. "1 || X" would have constant |
| // folded if the case was simple enough. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == -1) { |
| // br(0 || X) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| } |
| |
| // If we have "X || 0", simplify the code to use an uncond branch. |
| // "X || 1" would have been constant folded to 1. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == -1) { |
| // br(X || 0) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is true, we |
| // want to jump to the TrueBlock. |
| llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false"); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse); |
| EmitBlock(LHSFalse); |
| |
| // Any temporaries created here are conditional. |
| BeginConditionalBranch(); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| EndConditionalBranch(); |
| |
| return; |
| } |
| } |
| |
| if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) { |
| // br(!x, t, f) -> br(x, f, t) |
| if (CondUOp->getOpcode() == UnaryOperator::LNot) |
| return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock); |
| } |
| |
| if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) { |
| // Handle ?: operator. |
| |
| // Just ignore GNU ?: extension. |
| if (CondOp->getLHS()) { |
| // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f)) |
| llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true"); |
| llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false"); |
| EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock); |
| EmitBlock(LHSBlock); |
| EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock); |
| EmitBlock(RHSBlock); |
| EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock); |
| return; |
| } |
| } |
| |
| // Emit the code with the fully general case. |
| llvm::Value *CondV = EvaluateExprAsBool(Cond); |
| Builder.CreateCondBr(CondV, TrueBlock, FalseBlock); |
| } |
| |
| /// ErrorUnsupported - Print out an error that codegen doesn't support the |
| /// specified stmt yet. |
| void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type, |
| bool OmitOnError) { |
| CGM.ErrorUnsupported(S, Type, OmitOnError); |
| } |
| |
| void |
| CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) { |
| // If the type contains a pointer to data member we can't memset it to zero. |
| // Instead, create a null constant and copy it to the destination. |
| if (CGM.getTypes().ContainsPointerToDataMember(Ty)) { |
| llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty); |
| |
| llvm::GlobalVariable *NullVariable = |
| new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(), |
| /*isConstant=*/true, |
| llvm::GlobalVariable::PrivateLinkage, |
| NullConstant, llvm::Twine()); |
| EmitAggregateCopy(DestPtr, NullVariable, Ty, /*isVolatile=*/false); |
| return; |
| } |
| |
| |
| // Ignore empty classes in C++. |
| if (getContext().getLangOptions().CPlusPlus) { |
| if (const RecordType *RT = Ty->getAs<RecordType>()) { |
| if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty()) |
| return; |
| } |
| } |
| |
| // Otherwise, just memset the whole thing to zero. This is legal |
| // because in LLVM, all default initializers (other than the ones we just |
| // handled above) are guaranteed to have a bit pattern of all zeros. |
| const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext); |
| if (DestPtr->getType() != BP) |
| DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp"); |
| |
| // Get size and alignment info for this aggregate. |
| std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty); |
| |
| // Don't bother emitting a zero-byte memset. |
| if (TypeInfo.first == 0) |
| return; |
| |
| // FIXME: Handle variable sized types. |
| Builder.CreateCall5(CGM.getMemSetFn(BP, IntPtrTy), DestPtr, |
| llvm::Constant::getNullValue(llvm::Type::getInt8Ty(VMContext)), |
| // TypeInfo.first describes size in bits. |
| llvm::ConstantInt::get(IntPtrTy, TypeInfo.first/8), |
| llvm::ConstantInt::get(Int32Ty, TypeInfo.second/8), |
| llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), |
| 0)); |
| } |
| |
| llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelStmt *L) { |
| // Make sure that there is a block for the indirect goto. |
| if (IndirectBranch == 0) |
| GetIndirectGotoBlock(); |
| |
| llvm::BasicBlock *BB = getJumpDestForLabel(L).Block; |
| |
| // Make sure the indirect branch includes all of the address-taken blocks. |
| IndirectBranch->addDestination(BB); |
| return llvm::BlockAddress::get(CurFn, BB); |
| } |
| |
| llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() { |
| // If we already made the indirect branch for indirect goto, return its block. |
| if (IndirectBranch) return IndirectBranch->getParent(); |
| |
| CGBuilderTy TmpBuilder(createBasicBlock("indirectgoto")); |
| |
| const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext); |
| |
| // Create the PHI node that indirect gotos will add entries to. |
| llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, "indirect.goto.dest"); |
| |
| // Create the indirect branch instruction. |
| IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal); |
| return IndirectBranch->getParent(); |
| } |
| |
| llvm::Value *CodeGenFunction::GetVLASize(const VariableArrayType *VAT) { |
| llvm::Value *&SizeEntry = VLASizeMap[VAT->getSizeExpr()]; |
| |
| assert(SizeEntry && "Did not emit size for type"); |
| return SizeEntry; |
| } |
| |
| llvm::Value *CodeGenFunction::EmitVLASize(QualType Ty) { |
| assert(Ty->isVariablyModifiedType() && |
| "Must pass variably modified type to EmitVLASizes!"); |
| |
| EnsureInsertPoint(); |
| |
| if (const VariableArrayType *VAT = getContext().getAsVariableArrayType(Ty)) { |
| llvm::Value *&SizeEntry = VLASizeMap[VAT->getSizeExpr()]; |
| |
| if (!SizeEntry) { |
| const llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); |
| |
| // Get the element size; |
| QualType ElemTy = VAT->getElementType(); |
| llvm::Value *ElemSize; |
| if (ElemTy->isVariableArrayType()) |
| ElemSize = EmitVLASize(ElemTy); |
| else |
| ElemSize = llvm::ConstantInt::get(SizeTy, |
| getContext().getTypeSizeInChars(ElemTy).getQuantity()); |
| |
| llvm::Value *NumElements = EmitScalarExpr(VAT->getSizeExpr()); |
| NumElements = Builder.CreateIntCast(NumElements, SizeTy, false, "tmp"); |
| |
| SizeEntry = Builder.CreateMul(ElemSize, NumElements); |
| } |
| |
| return SizeEntry; |
| } |
| |
| if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) { |
| EmitVLASize(AT->getElementType()); |
| return 0; |
| } |
| |
| const PointerType *PT = Ty->getAs<PointerType>(); |
| assert(PT && "unknown VM type!"); |
| EmitVLASize(PT->getPointeeType()); |
| return 0; |
| } |
| |
| llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) { |
| if (CGM.getContext().getBuiltinVaListType()->isArrayType()) |
| return EmitScalarExpr(E); |
| return EmitLValue(E).getAddress(); |
| } |
| |
| /// Pops cleanup blocks until the given savepoint is reached. |
| void CodeGenFunction::PopCleanupBlocks(EHScopeStack::stable_iterator Old) { |
| assert(Old.isValid()); |
| |
| EHScopeStack::iterator E = EHStack.find(Old); |
| while (EHStack.begin() != E) |
| PopCleanupBlock(); |
| } |
| |
| /// Destroys a cleanup if it was unused. |
| static void DestroyCleanup(CodeGenFunction &CGF, |
| llvm::BasicBlock *Entry, |
| llvm::BasicBlock *Exit) { |
| assert(Entry->use_empty() && "destroying cleanup with uses!"); |
| assert(Exit->getTerminator() == 0 && |
| "exit has terminator but entry has no predecessors!"); |
| |
| // This doesn't always remove the entire cleanup, but it's much |
| // safer as long as we don't know what blocks belong to the cleanup. |
| // A *much* better approach if we care about this inefficiency would |
| // be to lazily emit the cleanup. |
| |
| // If the exit block is distinct from the entry, give it a branch to |
| // an unreachable destination. This preserves the well-formedness |
| // of the IR. |
| if (Entry != Exit) |
| llvm::BranchInst::Create(CGF.getUnreachableBlock(), Exit); |
| |
| assert(!Entry->getParent() && "cleanup entry already positioned?"); |
| // We can't just delete the entry; we have to kill any references to |
| // its instructions in other blocks. |
| for (llvm::BasicBlock::iterator I = Entry->begin(), E = Entry->end(); |
| I != E; ++I) |
| if (!I->use_empty()) |
| I->replaceAllUsesWith(llvm::UndefValue::get(I->getType())); |
| delete Entry; |
| } |
| |
| /// Creates a switch instruction to thread branches out of the given |
| /// block (which is the exit block of a cleanup). |
| static void CreateCleanupSwitch(CodeGenFunction &CGF, |
| llvm::BasicBlock *Block) { |
| if (Block->getTerminator()) { |
| assert(isa<llvm::SwitchInst>(Block->getTerminator()) && |
| "cleanup block already has a terminator, but it isn't a switch"); |
| return; |
| } |
| |
| llvm::Value *DestCodePtr |
| = CGF.CreateTempAlloca(CGF.Builder.getInt32Ty(), "cleanup.dst"); |
| CGBuilderTy Builder(Block); |
| llvm::Value *DestCode = Builder.CreateLoad(DestCodePtr, "tmp"); |
| |
| // Create a switch instruction to determine where to jump next. |
| Builder.CreateSwitch(DestCode, CGF.getUnreachableBlock()); |
| } |
| |
| /// Attempts to reduce a cleanup's entry block to a fallthrough. This |
| /// is basically llvm::MergeBlockIntoPredecessor, except |
| /// simplified/optimized for the tighter constraints on cleanup |
| /// blocks. |
| static void SimplifyCleanupEntry(CodeGenFunction &CGF, |
| llvm::BasicBlock *Entry) { |
| llvm::BasicBlock *Pred = Entry->getSinglePredecessor(); |
| if (!Pred) return; |
| |
| llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator()); |
| if (!Br || Br->isConditional()) return; |
| assert(Br->getSuccessor(0) == Entry); |
| |
| // If we were previously inserting at the end of the cleanup entry |
| // block, we'll need to continue inserting at the end of the |
| // predecessor. |
| bool WasInsertBlock = CGF.Builder.GetInsertBlock() == Entry; |
| assert(!WasInsertBlock || CGF.Builder.GetInsertPoint() == Entry->end()); |
| |
| // Kill the branch. |
| Br->eraseFromParent(); |
| |
| // Merge the blocks. |
| Pred->getInstList().splice(Pred->end(), Entry->getInstList()); |
| |
| // Kill the entry block. |
| Entry->eraseFromParent(); |
| |
| if (WasInsertBlock) |
| CGF.Builder.SetInsertPoint(Pred); |
| } |
| |
| /// Attempts to reduce an cleanup's exit switch to an unconditional |
| /// branch. |
| static void SimplifyCleanupExit(llvm::BasicBlock *Exit) { |
| llvm::TerminatorInst *Terminator = Exit->getTerminator(); |
| assert(Terminator && "completed cleanup exit has no terminator"); |
| |
| llvm::SwitchInst *Switch = dyn_cast<llvm::SwitchInst>(Terminator); |
| if (!Switch) return; |
| if (Switch->getNumCases() != 2) return; // default + 1 |
| |
| llvm::LoadInst *Cond = cast<llvm::LoadInst>(Switch->getCondition()); |
| llvm::AllocaInst *CondVar = cast<llvm::AllocaInst>(Cond->getPointerOperand()); |
| |
| // Replace the switch instruction with an unconditional branch. |
| llvm::BasicBlock *Dest = Switch->getSuccessor(1); // default is 0 |
| Switch->eraseFromParent(); |
| llvm::BranchInst::Create(Dest, Exit); |
| |
| // Delete all uses of the condition variable. |
| Cond->eraseFromParent(); |
| while (!CondVar->use_empty()) |
| cast<llvm::StoreInst>(*CondVar->use_begin())->eraseFromParent(); |
| |
| // Delete the condition variable itself. |
| CondVar->eraseFromParent(); |
| } |
| |
| /// Threads a branch fixup through a cleanup block. |
| static void ThreadFixupThroughCleanup(CodeGenFunction &CGF, |
| BranchFixup &Fixup, |
| llvm::BasicBlock *Entry, |
| llvm::BasicBlock *Exit) { |
| if (!Exit->getTerminator()) |
| CreateCleanupSwitch(CGF, Exit); |
| |
| // Find the switch and its destination index alloca. |
| llvm::SwitchInst *Switch = cast<llvm::SwitchInst>(Exit->getTerminator()); |
| llvm::Value *DestCodePtr = |
| cast<llvm::LoadInst>(Switch->getCondition())->getPointerOperand(); |
| |
| // Compute the index of the new case we're adding to the switch. |
| unsigned Index = Switch->getNumCases(); |
| |
| const llvm::IntegerType *i32 = llvm::Type::getInt32Ty(CGF.getLLVMContext()); |
| llvm::ConstantInt *IndexV = llvm::ConstantInt::get(i32, Index); |
| |
| // Set the index in the origin block. |
| new llvm::StoreInst(IndexV, DestCodePtr, Fixup.Origin); |
| |
| // Add a case to the switch. |
| Switch->addCase(IndexV, Fixup.Destination); |
| |
| // Change the last branch to point to the cleanup entry block. |
| Fixup.LatestBranch->setSuccessor(Fixup.LatestBranchIndex, Entry); |
| |
| // And finally, update the fixup. |
| Fixup.LatestBranch = Switch; |
| Fixup.LatestBranchIndex = Index; |
| } |
| |
| /// Try to simplify both the entry and exit edges of a cleanup. |
| static void SimplifyCleanupEdges(CodeGenFunction &CGF, |
| llvm::BasicBlock *Entry, |
| llvm::BasicBlock *Exit) { |
| |
| // Given their current implementations, it's important to run these |
| // in this order: SimplifyCleanupEntry will delete Entry if it can |
| // be merged into its predecessor, which will then break |
| // SimplifyCleanupExit if (as is common) Entry == Exit. |
| |
| SimplifyCleanupExit(Exit); |
| SimplifyCleanupEntry(CGF, Entry); |
| } |
| |
| static void EmitLazyCleanup(CodeGenFunction &CGF, |
| EHScopeStack::LazyCleanup *Fn, |
| bool ForEH) { |
| if (ForEH) CGF.EHStack.pushTerminate(); |
| Fn->Emit(CGF, ForEH); |
| if (ForEH) CGF.EHStack.popTerminate(); |
| assert(CGF.HaveInsertPoint() && "cleanup ended with no insertion point?"); |
| } |
| |
| static void SplitAndEmitLazyCleanup(CodeGenFunction &CGF, |
| EHScopeStack::LazyCleanup *Fn, |
| bool ForEH, |
| llvm::BasicBlock *Entry) { |
| assert(Entry && "no entry block for cleanup"); |
| |
| // Remove the switch and load from the end of the entry block. |
| llvm::Instruction *Switch = &Entry->getInstList().back(); |
| Entry->getInstList().remove(Switch); |
| assert(isa<llvm::SwitchInst>(Switch)); |
| llvm::Instruction *Load = &Entry->getInstList().back(); |
| Entry->getInstList().remove(Load); |
| assert(isa<llvm::LoadInst>(Load)); |
| |
| assert(Entry->getInstList().empty() && |
| "lazy cleanup block not empty after removing load/switch pair?"); |
| |
| // Emit the actual cleanup at the end of the entry block. |
| CGF.Builder.SetInsertPoint(Entry); |
| EmitLazyCleanup(CGF, Fn, ForEH); |
| |
| // Put the load and switch at the end of the exit block. |
| llvm::BasicBlock *Exit = CGF.Builder.GetInsertBlock(); |
| Exit->getInstList().push_back(Load); |
| Exit->getInstList().push_back(Switch); |
| |
| // Clean up the edges if possible. |
| SimplifyCleanupEdges(CGF, Entry, Exit); |
| |
| CGF.Builder.ClearInsertionPoint(); |
| } |
| |
| static void PopLazyCleanupBlock(CodeGenFunction &CGF) { |
| assert(isa<EHLazyCleanupScope>(*CGF.EHStack.begin()) && "top not a cleanup!"); |
| EHLazyCleanupScope &Scope = cast<EHLazyCleanupScope>(*CGF.EHStack.begin()); |
| assert(Scope.getFixupDepth() <= CGF.EHStack.getNumBranchFixups()); |
| |
| // Check whether we need an EH cleanup. This is only true if we've |
| // generated a lazy EH cleanup block. |
| llvm::BasicBlock *EHEntry = Scope.getEHBlock(); |
| bool RequiresEHCleanup = (EHEntry != 0); |
| |
| // Check the three conditions which might require a normal cleanup: |
| |
| // - whether there are branch fix-ups through this cleanup |
| unsigned FixupDepth = Scope.getFixupDepth(); |
| bool HasFixups = CGF.EHStack.getNumBranchFixups() != FixupDepth; |
| |
| // - whether control has already been threaded through this cleanup |
| llvm::BasicBlock *NormalEntry = Scope.getNormalBlock(); |
| bool HasExistingBranches = (NormalEntry != 0); |
| |
| // - whether there's a fallthrough |
| llvm::BasicBlock *FallthroughSource = CGF.Builder.GetInsertBlock(); |
| bool HasFallthrough = (FallthroughSource != 0); |
| |
| bool RequiresNormalCleanup = false; |
| if (Scope.isNormalCleanup() && |
| (HasFixups || HasExistingBranches || HasFallthrough)) { |
| RequiresNormalCleanup = true; |
| } |
| |
| // If we don't need the cleanup at all, we're done. |
| if (!RequiresNormalCleanup && !RequiresEHCleanup) { |
| CGF.EHStack.popCleanup(); |
| assert(CGF.EHStack.getNumBranchFixups() == 0 || |
| CGF.EHStack.hasNormalCleanups()); |
| return; |
| } |
| |
| // Copy the cleanup emission data out. Note that SmallVector |
| // guarantees maximal alignment for its buffer regardless of its |
| // type parameter. |
| llvm::SmallVector<char, 8*sizeof(void*)> CleanupBuffer; |
| CleanupBuffer.reserve(Scope.getCleanupSize()); |
| memcpy(CleanupBuffer.data(), |
| Scope.getCleanupBuffer(), Scope.getCleanupSize()); |
| CleanupBuffer.set_size(Scope.getCleanupSize()); |
| EHScopeStack::LazyCleanup *Fn = |
| reinterpret_cast<EHScopeStack::LazyCleanup*>(CleanupBuffer.data()); |
| |
| // We're done with the scope; pop it off so we can emit the cleanups. |
| CGF.EHStack.popCleanup(); |
| |
| if (RequiresNormalCleanup) { |
| // If we have a fallthrough and no other need for the cleanup, |
| // emit it directly. |
| if (HasFallthrough && !HasFixups && !HasExistingBranches) { |
| EmitLazyCleanup(CGF, Fn, /*ForEH*/ false); |
| |
| // Otherwise, the best approach is to thread everything through |
| // the cleanup block and then try to clean up after ourselves. |
| } else { |
| // Force the entry block to exist. |
| if (!HasExistingBranches) { |
| NormalEntry = CGF.createBasicBlock("cleanup"); |
| CreateCleanupSwitch(CGF, NormalEntry); |
| } |
| |
| CGF.EmitBlock(NormalEntry); |
| |
| // Thread the fallthrough edge through the (momentarily trivial) |
| // cleanup. |
| llvm::BasicBlock *FallthroughDestination = 0; |
| if (HasFallthrough) { |
| assert(isa<llvm::BranchInst>(FallthroughSource->getTerminator())); |
| FallthroughDestination = CGF.createBasicBlock("cleanup.cont"); |
| |
| BranchFixup Fix; |
| Fix.Destination = FallthroughDestination; |
| Fix.LatestBranch = FallthroughSource->getTerminator(); |
| Fix.LatestBranchIndex = 0; |
| Fix.Origin = Fix.LatestBranch; |
| |
| // Restore fixup invariant. EmitBlock added a branch to the |
| // cleanup which we need to redirect to the destination. |
| cast<llvm::BranchInst>(Fix.LatestBranch) |
| ->setSuccessor(0, Fix.Destination); |
| |
| ThreadFixupThroughCleanup(CGF, Fix, NormalEntry, NormalEntry); |
| } |
| |
| // Thread any "real" fixups we need to thread. |
| for (unsigned I = FixupDepth, E = CGF.EHStack.getNumBranchFixups(); |
| I != E; ++I) |
| if (CGF.EHStack.getBranchFixup(I).Destination) |
| ThreadFixupThroughCleanup(CGF, CGF.EHStack.getBranchFixup(I), |
| NormalEntry, NormalEntry); |
| |
| SplitAndEmitLazyCleanup(CGF, Fn, /*ForEH*/ false, NormalEntry); |
| |
| if (HasFallthrough) |
| CGF.EmitBlock(FallthroughDestination); |
| } |
| } |
| |
| // Emit the EH cleanup if required. |
| if (RequiresEHCleanup) { |
| CGBuilderTy::InsertPoint SavedIP = CGF.Builder.saveAndClearIP(); |
| CGF.EmitBlock(EHEntry); |
| SplitAndEmitLazyCleanup(CGF, Fn, /*ForEH*/ true, EHEntry); |
| CGF.Builder.restoreIP(SavedIP); |
| } |
| } |
| |
| /// Pops a cleanup block. If the block includes a normal cleanup, the |
| /// current insertion point is threaded through the cleanup, as are |
| /// any branch fixups on the cleanup. |
| void CodeGenFunction::PopCleanupBlock() { |
| assert(!EHStack.empty() && "cleanup stack is empty!"); |
| if (isa<EHLazyCleanupScope>(*EHStack.begin())) |
| return PopLazyCleanupBlock(*this); |
| |
| assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!"); |
| EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); |
| assert(Scope.getFixupDepth() <= EHStack.getNumBranchFixups()); |
| |
| // Handle the EH cleanup if (1) there is one and (2) it's different |
| // from the normal cleanup. |
| if (Scope.isEHCleanup() && |
| Scope.getEHEntry() != Scope.getNormalEntry()) { |
| llvm::BasicBlock *EHEntry = Scope.getEHEntry(); |
| llvm::BasicBlock *EHExit = Scope.getEHExit(); |
| |
| if (EHEntry->use_empty()) { |
| DestroyCleanup(*this, EHEntry, EHExit); |
| } else { |
| // TODO: this isn't really the ideal location to put this EH |
| // cleanup, but lazy emission is a better solution than trying |
| // to pick a better spot. |
| CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); |
| EmitBlock(EHEntry); |
| Builder.restoreIP(SavedIP); |
| |
| SimplifyCleanupEdges(*this, EHEntry, EHExit); |
| } |
| } |
| |
| // If we only have an EH cleanup, we don't really need to do much |
| // here. Branch fixups just naturally drop down to the enclosing |
| // cleanup scope. |
| if (!Scope.isNormalCleanup()) { |
| EHStack.popCleanup(); |
| assert(EHStack.getNumBranchFixups() == 0 || EHStack.hasNormalCleanups()); |
| return; |
| } |
| |
| // Check whether the scope has any fixups that need to be threaded. |
| unsigned FixupDepth = Scope.getFixupDepth(); |
| bool HasFixups = EHStack.getNumBranchFixups() != FixupDepth; |
| |
| // Grab the entry and exit blocks. |
| llvm::BasicBlock *Entry = Scope.getNormalEntry(); |
| llvm::BasicBlock *Exit = Scope.getNormalExit(); |
| |
| // Check whether anything's been threaded through the cleanup already. |
| assert((Exit->getTerminator() == 0) == Entry->use_empty() && |
| "cleanup entry/exit mismatch"); |
| bool HasExistingBranches = !Entry->use_empty(); |
| |
| // Check whether we need to emit a "fallthrough" branch through the |
| // cleanup for the current insertion point. |
| llvm::BasicBlock *FallThrough = Builder.GetInsertBlock(); |
| if (FallThrough && FallThrough->getTerminator()) |
| FallThrough = 0; |
| |
| // If *nothing* is using the cleanup, kill it. |
| if (!FallThrough && !HasFixups && !HasExistingBranches) { |
| EHStack.popCleanup(); |
| DestroyCleanup(*this, Entry, Exit); |
| return; |
| } |
| |
| // Otherwise, add the block to the function. |
| EmitBlock(Entry); |
| |
| if (FallThrough) |
| Builder.SetInsertPoint(Exit); |
| else |
| Builder.ClearInsertionPoint(); |
| |
| // Fast case: if we don't have to add any fixups, and either |
| // we don't have a fallthrough or the cleanup wasn't previously |
| // used, then the setup above is sufficient. |
| if (!HasFixups) { |
| if (!FallThrough) { |
| assert(HasExistingBranches && "no reason for cleanup but didn't kill before"); |
| EHStack.popCleanup(); |
| SimplifyCleanupEdges(*this, Entry, Exit); |
| return; |
| } else if (!HasExistingBranches) { |
| assert(FallThrough && "no reason for cleanup but didn't kill before"); |
| // We can't simplify the exit edge in this case because we're |
| // already inserting at the end of the exit block. |
| EHStack.popCleanup(); |
| SimplifyCleanupEntry(*this, Entry); |
| return; |
| } |
| } |
| |
| // Otherwise we're going to have to thread things through the cleanup. |
| llvm::SmallVector<BranchFixup*, 8> Fixups; |
| |
| // Synthesize a fixup for the current insertion point. |
| BranchFixup Cur; |
| if (FallThrough) { |
| Cur.Destination = createBasicBlock("cleanup.cont"); |
| Cur.LatestBranch = FallThrough->getTerminator(); |
| Cur.LatestBranchIndex = 0; |
| Cur.Origin = Cur.LatestBranch; |
| |
| // Restore fixup invariant. EmitBlock added a branch to the cleanup |
| // which we need to redirect to the destination. |
| cast<llvm::BranchInst>(Cur.LatestBranch)->setSuccessor(0, Cur.Destination); |
| |
| Fixups.push_back(&Cur); |
| } else { |
| Cur.Destination = 0; |
| } |
| |
| // Collect any "real" fixups we need to thread. |
| for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); |
| I != E; ++I) |
| if (EHStack.getBranchFixup(I).Destination) |
| Fixups.push_back(&EHStack.getBranchFixup(I)); |
| |
| assert(!Fixups.empty() && "no fixups, invariants broken!"); |
| |
| // If there's only a single fixup to thread through, do so with |
| // unconditional branches. This only happens if there's a single |
| // branch and no fallthrough. |
| if (Fixups.size() == 1 && !HasExistingBranches) { |
| Fixups[0]->LatestBranch->setSuccessor(Fixups[0]->LatestBranchIndex, Entry); |
| llvm::BranchInst *Br = |
| llvm::BranchInst::Create(Fixups[0]->Destination, Exit); |
| Fixups[0]->LatestBranch = Br; |
| Fixups[0]->LatestBranchIndex = 0; |
| |
| // Otherwise, force a switch statement and thread everything through |
| // the switch. |
| } else { |
| CreateCleanupSwitch(*this, Exit); |
| for (unsigned I = 0, E = Fixups.size(); I != E; ++I) |
| ThreadFixupThroughCleanup(*this, *Fixups[I], Entry, Exit); |
| } |
| |
| // Emit the fallthrough destination block if necessary. |
| if (Cur.Destination) |
| EmitBlock(Cur.Destination); |
| |
| // We're finally done with the cleanup. |
| EHStack.popCleanup(); |
| } |
| |
| void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) { |
| if (!HaveInsertPoint()) |
| return; |
| |
| // Create the branch. |
| llvm::BranchInst *BI = Builder.CreateBr(Dest.Block); |
| |
| // If we're not in a cleanup scope, we don't need to worry about |
| // fixups. |
| if (!EHStack.hasNormalCleanups()) { |
| Builder.ClearInsertionPoint(); |
| return; |
| } |
| |
| // Initialize a fixup. |
| BranchFixup Fixup; |
| Fixup.Destination = Dest.Block; |
| Fixup.Origin = BI; |
| Fixup.LatestBranch = BI; |
| Fixup.LatestBranchIndex = 0; |
| |
| // If we can't resolve the destination cleanup scope, just add this |
| // to the current cleanup scope. |
| if (!Dest.ScopeDepth.isValid()) { |
| EHStack.addBranchFixup() = Fixup; |
| Builder.ClearInsertionPoint(); |
| return; |
| } |
| |
| for (EHScopeStack::iterator I = EHStack.begin(), |
| E = EHStack.find(Dest.ScopeDepth); I != E; ++I) { |
| if (isa<EHCleanupScope>(*I)) { |
| EHCleanupScope &Scope = cast<EHCleanupScope>(*I); |
| if (Scope.isNormalCleanup()) |
| ThreadFixupThroughCleanup(*this, Fixup, Scope.getNormalEntry(), |
| Scope.getNormalExit()); |
| } else if (isa<EHLazyCleanupScope>(*I)) { |
| EHLazyCleanupScope &Scope = cast<EHLazyCleanupScope>(*I); |
| if (Scope.isNormalCleanup()) { |
| llvm::BasicBlock *Block = Scope.getNormalBlock(); |
| if (!Block) { |
| Block = createBasicBlock("cleanup"); |
| Scope.setNormalBlock(Block); |
| } |
| ThreadFixupThroughCleanup(*this, Fixup, Block, Block); |
| } |
| } |
| } |
| |
| Builder.ClearInsertionPoint(); |
| } |
| |
| void CodeGenFunction::EmitBranchThroughEHCleanup(JumpDest Dest) { |
| if (!HaveInsertPoint()) |
| return; |
| |
| // Create the branch. |
| llvm::BranchInst *BI = Builder.CreateBr(Dest.Block); |
| |
| // If we're not in a cleanup scope, we don't need to worry about |
| // fixups. |
| if (!EHStack.hasEHCleanups()) { |
| Builder.ClearInsertionPoint(); |
| return; |
| } |
| |
| // Initialize a fixup. |
| BranchFixup Fixup; |
| Fixup.Destination = Dest.Block; |
| Fixup.Origin = BI; |
| Fixup.LatestBranch = BI; |
| Fixup.LatestBranchIndex = 0; |
| |
| // We should never get invalid scope depths for these: invalid scope |
| // depths only arise for as-yet-unemitted labels, and we can't do an |
| // EH-unwind to one of those. |
| assert(Dest.ScopeDepth.isValid() && "invalid scope depth on EH dest?"); |
| |
| for (EHScopeStack::iterator I = EHStack.begin(), |
| E = EHStack.find(Dest.ScopeDepth); I != E; ++I) { |
| if (isa<EHCleanupScope>(*I)) { |
| EHCleanupScope &Scope = cast<EHCleanupScope>(*I); |
| if (Scope.isEHCleanup()) |
| ThreadFixupThroughCleanup(*this, Fixup, Scope.getEHEntry(), |
| Scope.getEHExit()); |
| } else if (isa<EHLazyCleanupScope>(*I)) { |
| EHLazyCleanupScope &Scope = cast<EHLazyCleanupScope>(*I); |
| if (Scope.isEHCleanup()) { |
| llvm::BasicBlock *Block = Scope.getEHBlock(); |
| if (!Block) { |
| Block = createBasicBlock("eh.cleanup"); |
| Scope.setEHBlock(Block); |
| } |
| ThreadFixupThroughCleanup(*this, Fixup, Block, Block); |
| } |
| } |
| } |
| |
| Builder.ClearInsertionPoint(); |
| } |