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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp | 1341 |
1 files changed, 1341 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp new file mode 100644 index 0000000..51d084e --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp @@ -0,0 +1,1341 @@ +//===--- 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 "CGCXXABI.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()), + NormalCleanupDest(0), EHCleanupDest(0), NextCleanupDestIndex(1), + ExceptionSlot(0), DebugInfo(0), IndirectBranch(0), + SwitchInsn(0), CaseRangeBlock(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.getCXXABI().getMangleContext().startNewFunction(); +} + +ASTContext &CodeGenFunction::getContext() const { + return CGM.getContext(); +} + + +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->isObjCObjectType(); +} + +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.getBlock()->use_empty()) { + ReturnBlock.getBlock()->replaceAllUsesWith(CurBB); + delete ReturnBlock.getBlock(); + } else + EmitBlock(ReturnBlock.getBlock()); + 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.getBlock()->hasOneUse()) { + llvm::BranchInst *BI = + dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin()); + if (BI && BI->isUnconditional() && + BI->getSuccessor(0) == ReturnBlock.getBlock()) { + // Reset insertion point and delete the branch. + Builder.SetInsertPoint(BI->getParent()); + BI->eraseFromParent(); + delete ReturnBlock.getBlock(); + 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.getBlock()); +} + +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->EmitFunctionEnd(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, RethrowBlock.getBlock()); + 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 (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) + CGM.getCXXABI().EmitInstanceFunctionProlog(*this); + + // 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()); +} + +/// Tries to mark the given function nounwind based on the +/// non-existence of any throwing calls within it. We believe this is +/// lightweight enough to do at -O0. +static void TryMarkNoThrow(llvm::Function *F) { + // LLVM treats 'nounwind' on a function as part of the type, so we + // can't do this on functions that can be overwritten. + if (F->mayBeOverridden()) return; + + for (llvm::Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI) + for (llvm::BasicBlock::iterator + BI = FI->begin(), BE = FI->end(); BI != BE; ++BI) + if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(&*BI)) + if (!Call->doesNotThrow()) + return; + F->setDoesNotThrow(true); +} + +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; + QualType ResTy = FD->getResultType(); + + CurGD = GD; + if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance()) + CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args); + + 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, ResTy, 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()); + + // If we haven't marked the function nothrow through other means, do + // a quick pass now to see if we can. + if (!CurFn->doesNotThrow()) + TryMarkNoThrow(CurFn); +} + +/// 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() == BO_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() == BO_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() == UO_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) { + // Ignore empty classes in C++. + if (getContext().getLangOptions().CPlusPlus) { + if (const RecordType *RT = Ty->getAs<RecordType>()) { + if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty()) + return; + } + } + + // Cast the dest ptr to the appropriate i8 pointer type. + unsigned DestAS = + cast<llvm::PointerType>(DestPtr->getType())->getAddressSpace(); + const llvm::Type *BP = + llvm::Type::getInt8PtrTy(VMContext, DestAS); + 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); + uint64_t Size = TypeInfo.first; + unsigned Align = TypeInfo.second; + + // Don't bother emitting a zero-byte memset. + if (Size == 0) + return; + + llvm::ConstantInt *SizeVal = llvm::ConstantInt::get(IntPtrTy, Size / 8); + llvm::ConstantInt *AlignVal = Builder.getInt32(Align / 8); + + // 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().isZeroInitializable(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()); + llvm::Value *SrcPtr = + Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy()); + + // FIXME: variable-size types? + + // Get and call the appropriate llvm.memcpy overload. + llvm::Constant *Memcpy = + CGM.getMemCpyFn(DestPtr->getType(), SrcPtr->getType(), IntPtrTy); + Builder.CreateCall5(Memcpy, DestPtr, SrcPtr, SizeVal, AlignVal, + /*volatile*/ Builder.getFalse()); + 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. + + // FIXME: Handle variable sized types. + Builder.CreateCall5(CGM.getMemSetFn(BP, IntPtrTy), DestPtr, + Builder.getInt8(0), + SizeVal, AlignVal, /*volatile*/ Builder.getFalse()); +} + +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).getBlock(); + + // 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()); + + while (EHStack.stable_begin() != Old) { + EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); + + // As long as Old strictly encloses the scope's enclosing normal + // cleanup, we're going to emit another normal cleanup which + // fallthrough can propagate through. + bool FallThroughIsBranchThrough = + Old.strictlyEncloses(Scope.getEnclosingNormalCleanup()); + + PopCleanupBlock(FallThroughIsBranchThrough); + } +} + +static llvm::BasicBlock *CreateNormalEntry(CodeGenFunction &CGF, + EHCleanupScope &Scope) { + assert(Scope.isNormalCleanup()); + llvm::BasicBlock *Entry = Scope.getNormalBlock(); + if (!Entry) { + Entry = CGF.createBasicBlock("cleanup"); + Scope.setNormalBlock(Entry); + } + return Entry; +} + +static llvm::BasicBlock *CreateEHEntry(CodeGenFunction &CGF, + EHCleanupScope &Scope) { + assert(Scope.isEHCleanup()); + llvm::BasicBlock *Entry = Scope.getEHBlock(); + if (!Entry) { + Entry = CGF.createBasicBlock("eh.cleanup"); + Scope.setEHBlock(Entry); + } + return Entry; +} + +/// Transitions the terminator of the given exit-block of a cleanup to +/// be a cleanup switch. +static llvm::SwitchInst *TransitionToCleanupSwitch(CodeGenFunction &CGF, + llvm::BasicBlock *Block) { + // If it's a branch, turn it into a switch whose default + // destination is its original target. + llvm::TerminatorInst *Term = Block->getTerminator(); + assert(Term && "can't transition block without terminator"); + + if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) { + assert(Br->isUnconditional()); + llvm::LoadInst *Load = + new llvm::LoadInst(CGF.getNormalCleanupDestSlot(), "cleanup.dest", Term); + llvm::SwitchInst *Switch = + llvm::SwitchInst::Create(Load, Br->getSuccessor(0), 4, Block); + Br->eraseFromParent(); + return Switch; + } else { + return cast<llvm::SwitchInst>(Term); + } +} + +/// 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. +/// +/// Returns the new block, whatever it is. +static llvm::BasicBlock *SimplifyCleanupEntry(CodeGenFunction &CGF, + llvm::BasicBlock *Entry) { + llvm::BasicBlock *Pred = Entry->getSinglePredecessor(); + if (!Pred) return Entry; + + llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator()); + if (!Br || Br->isConditional()) return Entry; + 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); + + return Pred; +} + +static void EmitCleanup(CodeGenFunction &CGF, + EHScopeStack::Cleanup *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?"); +} + +/// 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(bool FallthroughIsBranchThrough) { + assert(!EHStack.empty() && "cleanup stack is empty!"); + assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!"); + EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); + assert(Scope.getFixupDepth() <= EHStack.getNumBranchFixups()); + assert(Scope.isActive() && "cleanup was still inactive when popped!"); + + // Check whether we need an EH cleanup. This is only true if we've + // generated a lazy EH cleanup block. + bool RequiresEHCleanup = Scope.hasEHBranches(); + + // 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 = EHStack.getNumBranchFixups() != FixupDepth; + + // - whether there are branch-throughs or branch-afters + bool HasExistingBranches = Scope.hasBranches(); + + // - whether there's a fallthrough + llvm::BasicBlock *FallthroughSource = 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) { + EHStack.popCleanup(); // safe because there are no fixups + assert(EHStack.getNumBranchFixups() == 0 || + 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::Cleanup *Fn = + reinterpret_cast<EHScopeStack::Cleanup*>(CleanupBuffer.data()); + + // We want to emit the EH cleanup after the normal cleanup, but go + // ahead and do the setup for the EH cleanup while the scope is still + // alive. + llvm::BasicBlock *EHEntry = 0; + llvm::SmallVector<llvm::Instruction*, 2> EHInstsToAppend; + if (RequiresEHCleanup) { + EHEntry = CreateEHEntry(*this, Scope); + + // Figure out the branch-through dest if necessary. + llvm::BasicBlock *EHBranchThroughDest = 0; + if (Scope.hasEHBranchThroughs()) { + assert(Scope.getEnclosingEHCleanup() != EHStack.stable_end()); + EHScope &S = *EHStack.find(Scope.getEnclosingEHCleanup()); + EHBranchThroughDest = CreateEHEntry(*this, cast<EHCleanupScope>(S)); + } + + // If we have exactly one branch-after and no branch-throughs, we + // can dispatch it without a switch. + if (!Scope.hasEHBranchThroughs() && + Scope.getNumEHBranchAfters() == 1) { + assert(!EHBranchThroughDest); + + // TODO: remove the spurious eh.cleanup.dest stores if this edge + // never went through any switches. + llvm::BasicBlock *BranchAfterDest = Scope.getEHBranchAfterBlock(0); + EHInstsToAppend.push_back(llvm::BranchInst::Create(BranchAfterDest)); + + // Otherwise, if we have any branch-afters, we need a switch. + } else if (Scope.getNumEHBranchAfters()) { + // The default of the switch belongs to the branch-throughs if + // they exist. + llvm::BasicBlock *Default = + (EHBranchThroughDest ? EHBranchThroughDest : getUnreachableBlock()); + + const unsigned SwitchCapacity = Scope.getNumEHBranchAfters(); + + llvm::LoadInst *Load = + new llvm::LoadInst(getEHCleanupDestSlot(), "cleanup.dest"); + llvm::SwitchInst *Switch = + llvm::SwitchInst::Create(Load, Default, SwitchCapacity); + + EHInstsToAppend.push_back(Load); + EHInstsToAppend.push_back(Switch); + + for (unsigned I = 0, E = Scope.getNumEHBranchAfters(); I != E; ++I) + Switch->addCase(Scope.getEHBranchAfterIndex(I), + Scope.getEHBranchAfterBlock(I)); + + // Otherwise, we have only branch-throughs; jump to the next EH + // cleanup. + } else { + assert(EHBranchThroughDest); + EHInstsToAppend.push_back(llvm::BranchInst::Create(EHBranchThroughDest)); + } + } + + if (!RequiresNormalCleanup) { + EHStack.popCleanup(); + } else { + // As a kindof crazy internal case, branch-through fall-throughs + // leave the insertion point set to the end of the last cleanup. + bool HasPrebranchedFallthrough = + (HasFallthrough && FallthroughSource->getTerminator()); + assert(!HasPrebranchedFallthrough || + FallthroughSource->getTerminator()->getSuccessor(0) + == Scope.getNormalBlock()); + + // If we have a fallthrough and no other need for the cleanup, + // emit it directly. + if (HasFallthrough && !HasPrebranchedFallthrough && + !HasFixups && !HasExistingBranches) { + + // Fixups can cause us to optimistically create a normal block, + // only to later have no real uses for it. Just delete it in + // this case. + // TODO: we can potentially simplify all the uses after this. + if (Scope.getNormalBlock()) { + Scope.getNormalBlock()->replaceAllUsesWith(getUnreachableBlock()); + delete Scope.getNormalBlock(); + } + + EHStack.popCleanup(); + + EmitCleanup(*this, 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. + llvm::BasicBlock *NormalEntry = CreateNormalEntry(*this, Scope); + + // If there's a fallthrough, we need to store the cleanup + // destination index. For fall-throughs this is always zero. + if (HasFallthrough && !HasPrebranchedFallthrough) + Builder.CreateStore(Builder.getInt32(0), getNormalCleanupDestSlot()); + + // Emit the entry block. This implicitly branches to it if we + // have fallthrough. All the fixups and existing branches should + // already be branched to it. + EmitBlock(NormalEntry); + + bool HasEnclosingCleanups = + (Scope.getEnclosingNormalCleanup() != EHStack.stable_end()); + + // Compute the branch-through dest if we need it: + // - if there are branch-throughs threaded through the scope + // - if fall-through is a branch-through + // - if there are fixups that will be optimistically forwarded + // to the enclosing cleanup + llvm::BasicBlock *BranchThroughDest = 0; + if (Scope.hasBranchThroughs() || + (HasFallthrough && FallthroughIsBranchThrough) || + (HasFixups && HasEnclosingCleanups)) { + assert(HasEnclosingCleanups); + EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup()); + BranchThroughDest = CreateNormalEntry(*this, cast<EHCleanupScope>(S)); + } + + llvm::BasicBlock *FallthroughDest = 0; + llvm::SmallVector<llvm::Instruction*, 2> InstsToAppend; + + // If there's exactly one branch-after and no other threads, + // we can route it without a switch. + if (!Scope.hasBranchThroughs() && !HasFixups && !HasFallthrough && + Scope.getNumBranchAfters() == 1) { + assert(!BranchThroughDest); + + // TODO: clean up the possibly dead stores to the cleanup dest slot. + llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0); + InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter)); + + // Build a switch-out if we need it: + // - if there are branch-afters threaded through the scope + // - if fall-through is a branch-after + // - if there are fixups that have nowhere left to go and + // so must be immediately resolved + } else if (Scope.getNumBranchAfters() || + (HasFallthrough && !FallthroughIsBranchThrough) || + (HasFixups && !HasEnclosingCleanups)) { + + llvm::BasicBlock *Default = + (BranchThroughDest ? BranchThroughDest : getUnreachableBlock()); + + // TODO: base this on the number of branch-afters and fixups + const unsigned SwitchCapacity = 10; + + llvm::LoadInst *Load = + new llvm::LoadInst(getNormalCleanupDestSlot(), "cleanup.dest"); + llvm::SwitchInst *Switch = + llvm::SwitchInst::Create(Load, Default, SwitchCapacity); + + InstsToAppend.push_back(Load); + InstsToAppend.push_back(Switch); + + // Branch-after fallthrough. + if (HasFallthrough && !FallthroughIsBranchThrough) { + FallthroughDest = createBasicBlock("cleanup.cont"); + Switch->addCase(Builder.getInt32(0), FallthroughDest); + } + + for (unsigned I = 0, E = Scope.getNumBranchAfters(); I != E; ++I) { + Switch->addCase(Scope.getBranchAfterIndex(I), + Scope.getBranchAfterBlock(I)); + } + + if (HasFixups && !HasEnclosingCleanups) + ResolveAllBranchFixups(Switch); + } else { + // We should always have a branch-through destination in this case. + assert(BranchThroughDest); + InstsToAppend.push_back(llvm::BranchInst::Create(BranchThroughDest)); + } + + // We're finally ready to pop the cleanup. + EHStack.popCleanup(); + assert(EHStack.hasNormalCleanups() == HasEnclosingCleanups); + + EmitCleanup(*this, Fn, /*ForEH*/ false); + + // Append the prepared cleanup prologue from above. + llvm::BasicBlock *NormalExit = Builder.GetInsertBlock(); + for (unsigned I = 0, E = InstsToAppend.size(); I != E; ++I) + NormalExit->getInstList().push_back(InstsToAppend[I]); + + // Optimistically hope that any fixups will continue falling through. + for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); + I < E; ++I) { + BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I); + if (!Fixup.Destination) continue; + if (!Fixup.OptimisticBranchBlock) { + new llvm::StoreInst(Builder.getInt32(Fixup.DestinationIndex), + getNormalCleanupDestSlot(), + Fixup.InitialBranch); + Fixup.InitialBranch->setSuccessor(0, NormalEntry); + } + Fixup.OptimisticBranchBlock = NormalExit; + } + + if (FallthroughDest) + EmitBlock(FallthroughDest); + else if (!HasFallthrough) + Builder.ClearInsertionPoint(); + + // Check whether we can merge NormalEntry into a single predecessor. + // This might invalidate (non-IR) pointers to NormalEntry. + llvm::BasicBlock *NewNormalEntry = + SimplifyCleanupEntry(*this, NormalEntry); + + // If it did invalidate those pointers, and NormalEntry was the same + // as NormalExit, go back and patch up the fixups. + if (NewNormalEntry != NormalEntry && NormalEntry == NormalExit) + for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); + I < E; ++I) + CGF.EHStack.getBranchFixup(I).OptimisticBranchBlock = NewNormalEntry; + } + } + + assert(EHStack.hasNormalCleanups() || EHStack.getNumBranchFixups() == 0); + + // Emit the EH cleanup if required. + if (RequiresEHCleanup) { + CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); + + EmitBlock(EHEntry); + EmitCleanup(*this, Fn, /*ForEH*/ true); + + // Append the prepared cleanup prologue from above. + llvm::BasicBlock *EHExit = Builder.GetInsertBlock(); + for (unsigned I = 0, E = EHInstsToAppend.size(); I != E; ++I) + EHExit->getInstList().push_back(EHInstsToAppend[I]); + + Builder.restoreIP(SavedIP); + + SimplifyCleanupEntry(*this, EHEntry); + } +} + +/// Terminate the current block by emitting a branch which might leave +/// the current cleanup-protected scope. The target scope may not yet +/// be known, in which case this will require a fixup. +/// +/// As a side-effect, this method clears the insertion point. +void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) { + assert(Dest.getScopeDepth().encloses(EHStack.getInnermostNormalCleanup()) + && "stale jump destination"); + + if (!HaveInsertPoint()) + return; + + // Create the branch. + llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock()); + + // Calculate the innermost active normal cleanup. + EHScopeStack::stable_iterator + TopCleanup = EHStack.getInnermostActiveNormalCleanup(); + + // If we're not in an active normal cleanup scope, or if the + // destination scope is within the innermost active normal cleanup + // scope, we don't need to worry about fixups. + if (TopCleanup == EHStack.stable_end() || + TopCleanup.encloses(Dest.getScopeDepth())) { // works for invalid + Builder.ClearInsertionPoint(); + return; + } + + // If we can't resolve the destination cleanup scope, just add this + // to the current cleanup scope as a branch fixup. + if (!Dest.getScopeDepth().isValid()) { + BranchFixup &Fixup = EHStack.addBranchFixup(); + Fixup.Destination = Dest.getBlock(); + Fixup.DestinationIndex = Dest.getDestIndex(); + Fixup.InitialBranch = BI; + Fixup.OptimisticBranchBlock = 0; + + Builder.ClearInsertionPoint(); + return; + } + + // Otherwise, thread through all the normal cleanups in scope. + + // Store the index at the start. + llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex()); + new llvm::StoreInst(Index, getNormalCleanupDestSlot(), BI); + + // Adjust BI to point to the first cleanup block. + { + EHCleanupScope &Scope = + cast<EHCleanupScope>(*EHStack.find(TopCleanup)); + BI->setSuccessor(0, CreateNormalEntry(*this, Scope)); + } + + // Add this destination to all the scopes involved. + EHScopeStack::stable_iterator I = TopCleanup; + EHScopeStack::stable_iterator E = Dest.getScopeDepth(); + if (E.strictlyEncloses(I)) { + while (true) { + EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I)); + assert(Scope.isNormalCleanup()); + I = Scope.getEnclosingNormalCleanup(); + + // If this is the last cleanup we're propagating through, tell it + // that there's a resolved jump moving through it. + if (!E.strictlyEncloses(I)) { + Scope.addBranchAfter(Index, Dest.getBlock()); + break; + } + + // Otherwise, tell the scope that there's a jump propoagating + // through it. If this isn't new information, all the rest of + // the work has been done before. + if (!Scope.addBranchThrough(Dest.getBlock())) + break; + } + } + + Builder.ClearInsertionPoint(); +} + +void CodeGenFunction::EmitBranchThroughEHCleanup(UnwindDest Dest) { + // We should never get invalid scope depths for an UnwindDest; that + // implies that the destination wasn't set up correctly. + assert(Dest.getScopeDepth().isValid() && "invalid scope depth on EH dest?"); + + if (!HaveInsertPoint()) + return; + + // Create the branch. + llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock()); + + // Calculate the innermost active cleanup. + EHScopeStack::stable_iterator + InnermostCleanup = EHStack.getInnermostActiveEHCleanup(); + + // If the destination is in the same EH cleanup scope as us, we + // don't need to thread through anything. + if (InnermostCleanup.encloses(Dest.getScopeDepth())) { + Builder.ClearInsertionPoint(); + return; + } + assert(InnermostCleanup != EHStack.stable_end()); + + // Store the index at the start. + llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex()); + new llvm::StoreInst(Index, getEHCleanupDestSlot(), BI); + + // Adjust BI to point to the first cleanup block. + { + EHCleanupScope &Scope = + cast<EHCleanupScope>(*EHStack.find(InnermostCleanup)); + BI->setSuccessor(0, CreateEHEntry(*this, Scope)); + } + + // Add this destination to all the scopes involved. + for (EHScopeStack::stable_iterator + I = InnermostCleanup, E = Dest.getScopeDepth(); ; ) { + assert(E.strictlyEncloses(I)); + EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I)); + assert(Scope.isEHCleanup()); + I = Scope.getEnclosingEHCleanup(); + + // If this is the last cleanup we're propagating through, add this + // as a branch-after. + if (I == E) { + Scope.addEHBranchAfter(Index, Dest.getBlock()); + break; + } + + // Otherwise, add it as a branch-through. If this isn't new + // information, all the rest of the work has been done before. + if (!Scope.addEHBranchThrough(Dest.getBlock())) + break; + } + + Builder.ClearInsertionPoint(); +} + +/// All the branch fixups on the EH stack have propagated out past the +/// outermost normal cleanup; resolve them all by adding cases to the +/// given switch instruction. +void CodeGenFunction::ResolveAllBranchFixups(llvm::SwitchInst *Switch) { + llvm::SmallPtrSet<llvm::BasicBlock*, 4> CasesAdded; + + for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) { + // Skip this fixup if its destination isn't set or if we've + // already treated it. + BranchFixup &Fixup = EHStack.getBranchFixup(I); + if (Fixup.Destination == 0) continue; + if (!CasesAdded.insert(Fixup.Destination)) continue; + + Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), + Fixup.Destination); + } + + EHStack.clearFixups(); +} + +void CodeGenFunction::ResolveBranchFixups(llvm::BasicBlock *Block) { + assert(Block && "resolving a null target block"); + if (!EHStack.getNumBranchFixups()) return; + + assert(EHStack.hasNormalCleanups() && + "branch fixups exist with no normal cleanups on stack"); + + llvm::SmallPtrSet<llvm::BasicBlock*, 4> ModifiedOptimisticBlocks; + bool ResolvedAny = false; + + for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) { + // Skip this fixup if its destination doesn't match. + BranchFixup &Fixup = EHStack.getBranchFixup(I); + if (Fixup.Destination != Block) continue; + + Fixup.Destination = 0; + ResolvedAny = true; + + // If it doesn't have an optimistic branch block, LatestBranch is + // already pointing to the right place. + llvm::BasicBlock *BranchBB = Fixup.OptimisticBranchBlock; + if (!BranchBB) + continue; + + // Don't process the same optimistic branch block twice. + if (!ModifiedOptimisticBlocks.insert(BranchBB)) + continue; + + llvm::SwitchInst *Switch = TransitionToCleanupSwitch(*this, BranchBB); + + // Add a case to the switch. + Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), Block); + } + + if (ResolvedAny) + EHStack.popNullFixups(); +} + +/// Activate a cleanup that was created in an inactivated state. +void CodeGenFunction::ActivateCleanup(EHScopeStack::stable_iterator C) { + assert(C != EHStack.stable_end() && "activating bottom of stack?"); + EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C)); + assert(!Scope.isActive() && "double activation"); + + // Calculate whether the cleanup was used: + bool Used = false; + + // - as a normal cleanup + if (Scope.isNormalCleanup()) { + bool NormalUsed = false; + if (Scope.getNormalBlock()) { + NormalUsed = true; + } else { + // Check whether any enclosed cleanups were needed. + for (EHScopeStack::stable_iterator + I = EHStack.getInnermostNormalCleanup(); I != C; ) { + assert(C.strictlyEncloses(I)); + EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I)); + if (S.getNormalBlock()) { + NormalUsed = true; + break; + } + I = S.getEnclosingNormalCleanup(); + } + } + + if (NormalUsed) + Used = true; + else + Scope.setActivatedBeforeNormalUse(true); + } + + // - as an EH cleanup + if (Scope.isEHCleanup()) { + bool EHUsed = false; + if (Scope.getEHBlock()) { + EHUsed = true; + } else { + // Check whether any enclosed cleanups were needed. + for (EHScopeStack::stable_iterator + I = EHStack.getInnermostEHCleanup(); I != C; ) { + assert(C.strictlyEncloses(I)); + EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I)); + if (S.getEHBlock()) { + EHUsed = true; + break; + } + I = S.getEnclosingEHCleanup(); + } + } + + if (EHUsed) + Used = true; + else + Scope.setActivatedBeforeEHUse(true); + } + + llvm::AllocaInst *Var = EHCleanupScope::activeSentinel(); + if (Used) { + Var = CreateTempAlloca(Builder.getInt1Ty()); + InitTempAlloca(Var, Builder.getFalse()); + } + Scope.setActiveVar(Var); +} + +llvm::Value *CodeGenFunction::getNormalCleanupDestSlot() { + if (!NormalCleanupDest) + NormalCleanupDest = + CreateTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot"); + return NormalCleanupDest; +} + +llvm::Value *CodeGenFunction::getEHCleanupDestSlot() { + if (!EHCleanupDest) + EHCleanupDest = + CreateTempAlloca(Builder.getInt32Ty(), "eh.cleanup.dest.slot"); + return EHCleanupDest; +} + +void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E, + llvm::ConstantInt *Init) { + assert (Init && "Invalid DeclRefExpr initializer!"); + if (CGDebugInfo *Dbg = getDebugInfo()) + Dbg->EmitGlobalVariable(E->getDecl(), Init, Builder); +} |
