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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGException.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGException.cpp | 752 |
1 files changed, 752 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGException.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGException.cpp new file mode 100644 index 0000000..ddc1c77 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGException.cpp @@ -0,0 +1,752 @@ +//===--- CGException.cpp - Emit LLVM Code for C++ exceptions --------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code dealing with C++ exception related code generation. +// +//===----------------------------------------------------------------------===// + +#include "clang/AST/StmtCXX.h" + +#include "llvm/Intrinsics.h" + +#include "CodeGenFunction.h" +using namespace clang; +using namespace CodeGen; + +static llvm::Constant *getAllocateExceptionFn(CodeGenFunction &CGF) { + // void *__cxa_allocate_exception(size_t thrown_size); + const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType()); + std::vector<const llvm::Type*> Args(1, SizeTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getInt8PtrTy(CGF.getLLVMContext()), + Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_allocate_exception"); +} + +static llvm::Constant *getFreeExceptionFn(CodeGenFunction &CGF) { + // void __cxa_free_exception(void *thrown_exception); + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + std::vector<const llvm::Type*> Args(1, Int8PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), + Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_free_exception"); +} + +static llvm::Constant *getThrowFn(CodeGenFunction &CGF) { + // void __cxa_throw(void *thrown_exception, std::type_info *tinfo, + // void (*dest) (void *)); + + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + std::vector<const llvm::Type*> Args(3, Int8PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), + Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_throw"); +} + +static llvm::Constant *getReThrowFn(CodeGenFunction &CGF) { + // void __cxa_rethrow(); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_rethrow"); +} + +static llvm::Constant *getBeginCatchFn(CodeGenFunction &CGF) { + // void* __cxa_begin_catch(); + + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + std::vector<const llvm::Type*> Args(1, Int8PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(Int8PtrTy, Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_begin_catch"); +} + +static llvm::Constant *getEndCatchFn(CodeGenFunction &CGF) { + // void __cxa_end_catch(); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_end_catch"); +} + +static llvm::Constant *getUnexpectedFn(CodeGenFunction &CGF) { + // void __cxa_call_unexepcted(void *thrown_exception); + + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + std::vector<const llvm::Type*> Args(1, Int8PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), + Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_call_unexpected"); +} + +llvm::Constant *CodeGenFunction::getUnwindResumeOrRethrowFn() { + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext()); + std::vector<const llvm::Type*> Args(1, Int8PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(getLLVMContext()), Args, + false); + + if (CGM.getLangOptions().SjLjExceptions) + return CGM.CreateRuntimeFunction(FTy, "_Unwind_SjLj_Resume"); + return CGM.CreateRuntimeFunction(FTy, "_Unwind_Resume_or_Rethrow"); +} + +static llvm::Constant *getTerminateFn(CodeGenFunction &CGF) { + // void __terminate(); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), false); + + return CGF.CGM.CreateRuntimeFunction(FTy, + CGF.CGM.getLangOptions().CPlusPlus ? "_ZSt9terminatev" : "abort"); +} + +static llvm::Constant *getPersonalityFn(CodeGenModule &CGM) { + const char *PersonalityFnName = "__gcc_personality_v0"; + LangOptions Opts = CGM.getLangOptions(); + if (Opts.CPlusPlus) + PersonalityFnName = "__gxx_personality_v0"; + else if (Opts.ObjC1) { + if (Opts.NeXTRuntime) { + if (Opts.ObjCNonFragileABI) + PersonalityFnName = "__gcc_personality_v0"; + } else + PersonalityFnName = "__gnu_objc_personality_v0"; + } + + llvm::Constant *Personality = + CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty( + CGM.getLLVMContext()), + true), + PersonalityFnName); + return llvm::ConstantExpr::getBitCast(Personality, CGM.PtrToInt8Ty); +} + +// Emits an exception expression into the given location. This +// differs from EmitAnyExprToMem only in that, if a final copy-ctor +// call is required, an exception within that copy ctor causes +// std::terminate to be invoked. +static void EmitAnyExprToExn(CodeGenFunction &CGF, const Expr *E, + llvm::Value *ExnLoc) { + // We want to release the allocated exception object if this + // expression throws. We do this by pushing an EH-only cleanup + // block which, furthermore, deactivates itself after the expression + // is complete. + llvm::AllocaInst *ShouldFreeVar = + CGF.CreateTempAlloca(llvm::Type::getInt1Ty(CGF.getLLVMContext()), + "should-free-exnobj.var"); + CGF.InitTempAlloca(ShouldFreeVar, + llvm::ConstantInt::getFalse(CGF.getLLVMContext())); + + // A variable holding the exception pointer. This is necessary + // because the throw expression does not necessarily dominate the + // cleanup, for example if it appears in a conditional expression. + llvm::AllocaInst *ExnLocVar = + CGF.CreateTempAlloca(ExnLoc->getType(), "exnobj.var"); + + llvm::BasicBlock *SavedInvokeDest = CGF.getInvokeDest(); + { + CodeGenFunction::EHCleanupBlock Cleanup(CGF); + llvm::BasicBlock *FreeBB = CGF.createBasicBlock("free-exnobj"); + llvm::BasicBlock *DoneBB = CGF.createBasicBlock("free-exnobj.done"); + + llvm::Value *ShouldFree = CGF.Builder.CreateLoad(ShouldFreeVar, + "should-free-exnobj"); + CGF.Builder.CreateCondBr(ShouldFree, FreeBB, DoneBB); + CGF.EmitBlock(FreeBB); + llvm::Value *ExnLocLocal = CGF.Builder.CreateLoad(ExnLocVar, "exnobj"); + CGF.Builder.CreateCall(getFreeExceptionFn(CGF), ExnLocLocal); + CGF.EmitBlock(DoneBB); + } + llvm::BasicBlock *Cleanup = CGF.getInvokeDest(); + + CGF.Builder.CreateStore(ExnLoc, ExnLocVar); + CGF.Builder.CreateStore(llvm::ConstantInt::getTrue(CGF.getLLVMContext()), + ShouldFreeVar); + + // __cxa_allocate_exception returns a void*; we need to cast this + // to the appropriate type for the object. + const llvm::Type *Ty = CGF.ConvertType(E->getType())->getPointerTo(); + llvm::Value *TypedExnLoc = CGF.Builder.CreateBitCast(ExnLoc, Ty); + + // FIXME: this isn't quite right! If there's a final unelided call + // to a copy constructor, then according to [except.terminate]p1 we + // must call std::terminate() if that constructor throws, because + // technically that copy occurs after the exception expression is + // evaluated but before the exception is caught. But the best way + // to handle that is to teach EmitAggExpr to do the final copy + // differently if it can't be elided. + CGF.EmitAnyExprToMem(E, TypedExnLoc, /*Volatile*/ false); + + CGF.Builder.CreateStore(llvm::ConstantInt::getFalse(CGF.getLLVMContext()), + ShouldFreeVar); + + // Pop the cleanup block if it's still the top of the cleanup stack. + // Otherwise, temporaries have been created and our cleanup will get + // properly removed in time. + // TODO: this is not very resilient. + if (CGF.getInvokeDest() == Cleanup) + CGF.setInvokeDest(SavedInvokeDest); +} + +// CopyObject - Utility to copy an object. Calls copy constructor as necessary. +// N is casted to the right type. +static void CopyObject(CodeGenFunction &CGF, QualType ObjectType, + bool WasPointer, bool WasPointerReference, + llvm::Value *E, llvm::Value *N) { + // Store the throw exception in the exception object. + if (WasPointer || !CGF.hasAggregateLLVMType(ObjectType)) { + llvm::Value *Value = E; + if (!WasPointer) + Value = CGF.Builder.CreateLoad(Value); + const llvm::Type *ValuePtrTy = Value->getType()->getPointerTo(0); + if (WasPointerReference) { + llvm::Value *Tmp = CGF.CreateTempAlloca(Value->getType(), "catch.param"); + CGF.Builder.CreateStore(Value, Tmp); + Value = Tmp; + ValuePtrTy = Value->getType()->getPointerTo(0); + } + N = CGF.Builder.CreateBitCast(N, ValuePtrTy); + CGF.Builder.CreateStore(Value, N); + } else { + const llvm::Type *Ty = CGF.ConvertType(ObjectType)->getPointerTo(0); + const CXXRecordDecl *RD; + RD = cast<CXXRecordDecl>(ObjectType->getAs<RecordType>()->getDecl()); + llvm::Value *This = CGF.Builder.CreateBitCast(N, Ty); + if (RD->hasTrivialCopyConstructor()) { + CGF.EmitAggregateCopy(This, E, ObjectType); + } else if (CXXConstructorDecl *CopyCtor + = RD->getCopyConstructor(CGF.getContext(), 0)) { + llvm::Value *Src = E; + + // Stolen from EmitClassAggrMemberwiseCopy + llvm::Value *Callee = CGF.CGM.GetAddrOfCXXConstructor(CopyCtor, + Ctor_Complete); + CallArgList CallArgs; + CallArgs.push_back(std::make_pair(RValue::get(This), + CopyCtor->getThisType(CGF.getContext()))); + + // Push the Src ptr. + CallArgs.push_back(std::make_pair(RValue::get(Src), + CopyCtor->getParamDecl(0)->getType())); + + const FunctionProtoType *FPT + = CopyCtor->getType()->getAs<FunctionProtoType>(); + CGF.EmitCall(CGF.CGM.getTypes().getFunctionInfo(CallArgs, FPT), + Callee, ReturnValueSlot(), CallArgs, CopyCtor); + } else + llvm_unreachable("uncopyable object"); + } +} + +void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) { + if (!E->getSubExpr()) { + if (getInvokeDest()) { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + Builder.CreateInvoke(getReThrowFn(*this), Cont, getInvokeDest()) + ->setDoesNotReturn(); + EmitBlock(Cont); + } else + Builder.CreateCall(getReThrowFn(*this))->setDoesNotReturn(); + Builder.CreateUnreachable(); + + // Clear the insertion point to indicate we are in unreachable code. + Builder.ClearInsertionPoint(); + return; + } + + QualType ThrowType = E->getSubExpr()->getType(); + + // Now allocate the exception object. + const llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); + uint64_t TypeSize = getContext().getTypeSizeInChars(ThrowType).getQuantity(); + + llvm::Constant *AllocExceptionFn = getAllocateExceptionFn(*this); + llvm::Value *ExceptionPtr = + Builder.CreateCall(AllocExceptionFn, + llvm::ConstantInt::get(SizeTy, TypeSize), + "exception"); + + EmitAnyExprToExn(*this, E->getSubExpr(), ExceptionPtr); + + // Now throw the exception. + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext()); + llvm::Constant *TypeInfo = CGM.GetAddrOfRTTIDescriptor(ThrowType, true); + + // The address of the destructor. If the exception type has a + // trivial destructor (or isn't a record), we just pass null. + llvm::Constant *Dtor = 0; + if (const RecordType *RecordTy = ThrowType->getAs<RecordType>()) { + CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl()); + if (!Record->hasTrivialDestructor()) { + CXXDestructorDecl *DtorD = Record->getDestructor(getContext()); + Dtor = CGM.GetAddrOfCXXDestructor(DtorD, Dtor_Complete); + Dtor = llvm::ConstantExpr::getBitCast(Dtor, Int8PtrTy); + } + } + if (!Dtor) Dtor = llvm::Constant::getNullValue(Int8PtrTy); + + if (getInvokeDest()) { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + llvm::InvokeInst *ThrowCall = + Builder.CreateInvoke3(getThrowFn(*this), Cont, getInvokeDest(), + ExceptionPtr, TypeInfo, Dtor); + ThrowCall->setDoesNotReturn(); + EmitBlock(Cont); + } else { + llvm::CallInst *ThrowCall = + Builder.CreateCall3(getThrowFn(*this), ExceptionPtr, TypeInfo, Dtor); + ThrowCall->setDoesNotReturn(); + } + Builder.CreateUnreachable(); + + // Clear the insertion point to indicate we are in unreachable code. + Builder.ClearInsertionPoint(); + + // FIXME: For now, emit a dummy basic block because expr emitters in generally + // are not ready to handle emitting expressions at unreachable points. + EnsureInsertPoint(); +} + +void CodeGenFunction::EmitStartEHSpec(const Decl *D) { + if (!Exceptions) + return; + + const FunctionDecl* FD = dyn_cast_or_null<FunctionDecl>(D); + if (FD == 0) + return; + const FunctionProtoType *Proto = FD->getType()->getAs<FunctionProtoType>(); + if (Proto == 0) + return; + + assert(!Proto->hasAnyExceptionSpec() && "function with parameter pack"); + + if (!Proto->hasExceptionSpec()) + return; + + llvm::Constant *Personality = getPersonalityFn(CGM); + llvm::Value *llvm_eh_exception = + CGM.getIntrinsic(llvm::Intrinsic::eh_exception); + llvm::Value *llvm_eh_selector = + CGM.getIntrinsic(llvm::Intrinsic::eh_selector); + const llvm::IntegerType *Int8Ty; + const llvm::PointerType *PtrToInt8Ty; + Int8Ty = llvm::Type::getInt8Ty(VMContext); + // C string type. Used in lots of places. + PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); + llvm::Constant *Null = llvm::ConstantPointerNull::get(PtrToInt8Ty); + llvm::SmallVector<llvm::Value*, 8> SelectorArgs; + + llvm::BasicBlock *PrevLandingPad = getInvokeDest(); + llvm::BasicBlock *EHSpecHandler = createBasicBlock("ehspec.handler"); + llvm::BasicBlock *Match = createBasicBlock("match"); + llvm::BasicBlock *Unwind = 0; + + assert(PrevLandingPad == 0 && "EHSpec has invoke context"); + (void)PrevLandingPad; + + llvm::BasicBlock *Cont = createBasicBlock("cont"); + + EmitBranchThroughCleanup(Cont); + + // Emit the statements in the try {} block + setInvokeDest(EHSpecHandler); + + EmitBlock(EHSpecHandler); + // Exception object + llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + llvm::Value *RethrowPtr = CreateTempAlloca(Exc->getType(), "_rethrow"); + + SelectorArgs.push_back(Exc); + SelectorArgs.push_back(Personality); + SelectorArgs.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), + Proto->getNumExceptions()+1)); + + for (unsigned i = 0; i < Proto->getNumExceptions(); ++i) { + QualType Ty = Proto->getExceptionType(i); + QualType ExceptType + = Ty.getNonReferenceType().getUnqualifiedType(); + llvm::Value *EHType = CGM.GetAddrOfRTTIDescriptor(ExceptType, true); + SelectorArgs.push_back(EHType); + } + if (Proto->getNumExceptions()) + SelectorArgs.push_back(Null); + + // Find which handler was matched. + llvm::Value *Selector + = Builder.CreateCall(llvm_eh_selector, SelectorArgs.begin(), + SelectorArgs.end(), "selector"); + if (Proto->getNumExceptions()) { + Unwind = createBasicBlock("Unwind"); + + Builder.CreateStore(Exc, RethrowPtr); + Builder.CreateCondBr(Builder.CreateICmpSLT(Selector, + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), + 0)), + Match, Unwind); + + EmitBlock(Match); + } + Builder.CreateCall(getUnexpectedFn(*this), Exc)->setDoesNotReturn(); + Builder.CreateUnreachable(); + + if (Proto->getNumExceptions()) { + EmitBlock(Unwind); + Builder.CreateCall(getUnwindResumeOrRethrowFn(), + Builder.CreateLoad(RethrowPtr)); + Builder.CreateUnreachable(); + } + + EmitBlock(Cont); +} + +void CodeGenFunction::EmitEndEHSpec(const Decl *D) { + if (!Exceptions) + return; + + const FunctionDecl* FD = dyn_cast_or_null<FunctionDecl>(D); + if (FD == 0) + return; + const FunctionProtoType *Proto = FD->getType()->getAs<FunctionProtoType>(); + if (Proto == 0) + return; + + if (!Proto->hasExceptionSpec()) + return; + + setInvokeDest(0); +} + +void CodeGenFunction::EmitCXXTryStmt(const CXXTryStmt &S) { + CXXTryStmtInfo Info = EnterCXXTryStmt(S); + EmitStmt(S.getTryBlock()); + ExitCXXTryStmt(S, Info); +} + +CodeGenFunction::CXXTryStmtInfo +CodeGenFunction::EnterCXXTryStmt(const CXXTryStmt &S) { + CXXTryStmtInfo Info; + Info.SavedLandingPad = getInvokeDest(); + Info.HandlerBlock = createBasicBlock("try.handler"); + Info.FinallyBlock = createBasicBlock("finally"); + + PushCleanupBlock(Info.FinallyBlock); + setInvokeDest(Info.HandlerBlock); + + return Info; +} + +void CodeGenFunction::ExitCXXTryStmt(const CXXTryStmt &S, + CXXTryStmtInfo TryInfo) { + // Pointer to the personality function + llvm::Constant *Personality = getPersonalityFn(CGM); + llvm::Value *llvm_eh_exception = + CGM.getIntrinsic(llvm::Intrinsic::eh_exception); + llvm::Value *llvm_eh_selector = + CGM.getIntrinsic(llvm::Intrinsic::eh_selector); + + llvm::BasicBlock *PrevLandingPad = TryInfo.SavedLandingPad; + llvm::BasicBlock *TryHandler = TryInfo.HandlerBlock; + llvm::BasicBlock *FinallyBlock = TryInfo.FinallyBlock; + llvm::BasicBlock *FinallyRethrow = createBasicBlock("finally.throw"); + llvm::BasicBlock *FinallyEnd = createBasicBlock("finally.end"); + + // Jump to end if there is no exception + EmitBranchThroughCleanup(FinallyEnd); + + llvm::BasicBlock *TerminateHandler = getTerminateHandler(); + + // Emit the handlers + EmitBlock(TryHandler); + + const llvm::IntegerType *Int8Ty; + const llvm::PointerType *PtrToInt8Ty; + Int8Ty = llvm::Type::getInt8Ty(VMContext); + // C string type. Used in lots of places. + PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); + llvm::Constant *Null = llvm::ConstantPointerNull::get(PtrToInt8Ty); + llvm::SmallVector<llvm::Value*, 8> SelectorArgs; + llvm::Value *llvm_eh_typeid_for = + CGM.getIntrinsic(llvm::Intrinsic::eh_typeid_for); + // Exception object + llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + llvm::Value *RethrowPtr = CreateTempAlloca(Exc->getType(), "_rethrow"); + + SelectorArgs.push_back(Exc); + SelectorArgs.push_back(Personality); + + bool HasCatchAll = false; + for (unsigned i = 0; i<S.getNumHandlers(); ++i) { + const CXXCatchStmt *C = S.getHandler(i); + VarDecl *CatchParam = C->getExceptionDecl(); + if (CatchParam) { + // C++ [except.handle]p3 indicates that top-level cv-qualifiers + // are ignored. + QualType CaughtType = C->getCaughtType().getNonReferenceType(); + llvm::Value *EHTypeInfo + = CGM.GetAddrOfRTTIDescriptor(CaughtType.getUnqualifiedType(), true); + SelectorArgs.push_back(EHTypeInfo); + } else { + // null indicates catch all + SelectorArgs.push_back(Null); + HasCatchAll = true; + } + } + + // We use a cleanup unless there was already a catch all. + if (!HasCatchAll) { + SelectorArgs.push_back(Null); + } + + // Find which handler was matched. + llvm::Value *Selector + = Builder.CreateCall(llvm_eh_selector, SelectorArgs.begin(), + SelectorArgs.end(), "selector"); + for (unsigned i = 0; i<S.getNumHandlers(); ++i) { + const CXXCatchStmt *C = S.getHandler(i); + VarDecl *CatchParam = C->getExceptionDecl(); + Stmt *CatchBody = C->getHandlerBlock(); + + llvm::BasicBlock *Next = 0; + + if (SelectorArgs[i+2] != Null) { + llvm::BasicBlock *Match = createBasicBlock("match"); + Next = createBasicBlock("catch.next"); + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext()); + llvm::Value *Id + = Builder.CreateCall(llvm_eh_typeid_for, + Builder.CreateBitCast(SelectorArgs[i+2], + Int8PtrTy)); + Builder.CreateCondBr(Builder.CreateICmpEQ(Selector, Id), + Match, Next); + EmitBlock(Match); + } + + llvm::BasicBlock *MatchEnd = createBasicBlock("match.end"); + llvm::BasicBlock *MatchHandler = createBasicBlock("match.handler"); + + PushCleanupBlock(MatchEnd); + setInvokeDest(MatchHandler); + + llvm::Value *ExcObject = Builder.CreateCall(getBeginCatchFn(*this), Exc); + + { + CleanupScope CatchScope(*this); + // Bind the catch parameter if it exists. + if (CatchParam) { + QualType CatchType = CatchParam->getType().getNonReferenceType(); + setInvokeDest(TerminateHandler); + bool WasPointer = true; + bool WasPointerReference = false; + CatchType = CGM.getContext().getCanonicalType(CatchType); + if (CatchType.getTypePtr()->isPointerType()) { + if (isa<ReferenceType>(CatchParam->getType())) + WasPointerReference = true; + } else { + if (!isa<ReferenceType>(CatchParam->getType())) + WasPointer = false; + CatchType = getContext().getPointerType(CatchType); + } + ExcObject = Builder.CreateBitCast(ExcObject, ConvertType(CatchType)); + EmitLocalBlockVarDecl(*CatchParam); + // FIXME: we need to do this sooner so that the EH region for the + // cleanup doesn't start until after the ctor completes, use a decl + // init? + CopyObject(*this, CatchParam->getType().getNonReferenceType(), + WasPointer, WasPointerReference, ExcObject, + GetAddrOfLocalVar(CatchParam)); + setInvokeDest(MatchHandler); + } + + EmitStmt(CatchBody); + } + + EmitBranchThroughCleanup(FinallyEnd); + + EmitBlock(MatchHandler); + + llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + // We are required to emit this call to satisfy LLVM, even + // though we don't use the result. + llvm::Value *Args[] = { + Exc, Personality, + llvm::ConstantInt::getNullValue(llvm::Type::getInt32Ty(VMContext)) + }; + Builder.CreateCall(llvm_eh_selector, &Args[0], llvm::array_endof(Args)); + Builder.CreateStore(Exc, RethrowPtr); + EmitBranchThroughCleanup(FinallyRethrow); + + CodeGenFunction::CleanupBlockInfo Info = PopCleanupBlock(); + + EmitBlock(MatchEnd); + + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + Builder.CreateInvoke(getEndCatchFn(*this), + Cont, TerminateHandler, + &Args[0], &Args[0]); + EmitBlock(Cont); + if (Info.SwitchBlock) + EmitBlock(Info.SwitchBlock); + if (Info.EndBlock) + EmitBlock(Info.EndBlock); + + Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + Builder.CreateStore(Exc, RethrowPtr); + EmitBranchThroughCleanup(FinallyRethrow); + + if (Next) + EmitBlock(Next); + } + if (!HasCatchAll) { + Builder.CreateStore(Exc, RethrowPtr); + EmitBranchThroughCleanup(FinallyRethrow); + } + + CodeGenFunction::CleanupBlockInfo Info = PopCleanupBlock(); + + setInvokeDest(PrevLandingPad); + + EmitBlock(FinallyBlock); + + if (Info.SwitchBlock) + EmitBlock(Info.SwitchBlock); + if (Info.EndBlock) + EmitBlock(Info.EndBlock); + + // Branch around the rethrow code. + EmitBranch(FinallyEnd); + + EmitBlock(FinallyRethrow); + // FIXME: Eventually we can chain the handlers together and just do a call + // here. + if (getInvokeDest()) { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + Builder.CreateInvoke(getUnwindResumeOrRethrowFn(), Cont, + getInvokeDest(), + Builder.CreateLoad(RethrowPtr)); + EmitBlock(Cont); + } else + Builder.CreateCall(getUnwindResumeOrRethrowFn(), + Builder.CreateLoad(RethrowPtr)); + + Builder.CreateUnreachable(); + + EmitBlock(FinallyEnd); +} + +CodeGenFunction::EHCleanupBlock::~EHCleanupBlock() { + CGF.setInvokeDest(PreviousInvokeDest); + + llvm::BasicBlock *EndOfCleanup = CGF.Builder.GetInsertBlock(); + + // Jump to the beginning of the cleanup. + CGF.Builder.SetInsertPoint(CleanupHandler, CleanupHandler->begin()); + + // The libstdc++ personality function. + // TODO: generalize to work with other libraries. + llvm::Constant *Personality = getPersonalityFn(CGF.CGM); + + // %exception = call i8* @llvm.eh.exception() + // Magic intrinsic which tells gives us a handle to the caught + // exception. + llvm::Value *llvm_eh_exception = + CGF.CGM.getIntrinsic(llvm::Intrinsic::eh_exception); + llvm::Value *Exc = CGF.Builder.CreateCall(llvm_eh_exception, "exc"); + + llvm::Constant *Null = llvm::ConstantPointerNull::get(CGF.PtrToInt8Ty); + + // %ignored = call i32 @llvm.eh.selector(i8* %exception, + // i8* @__gxx_personality_v0, + // i8* null) + // Magic intrinsic which tells LLVM that this invoke landing pad is + // just a cleanup block. + llvm::Value *Args[] = { Exc, Personality, Null }; + llvm::Value *llvm_eh_selector = + CGF.CGM.getIntrinsic(llvm::Intrinsic::eh_selector); + CGF.Builder.CreateCall(llvm_eh_selector, &Args[0], llvm::array_endof(Args)); + + // And then we fall through into the code that the user put there. + // Jump back to the end of the cleanup. + CGF.Builder.SetInsertPoint(EndOfCleanup); + + // Rethrow the exception. + if (CGF.getInvokeDest()) { + llvm::BasicBlock *Cont = CGF.createBasicBlock("invoke.cont"); + CGF.Builder.CreateInvoke(CGF.getUnwindResumeOrRethrowFn(), Cont, + CGF.getInvokeDest(), Exc); + CGF.EmitBlock(Cont); + } else + CGF.Builder.CreateCall(CGF.getUnwindResumeOrRethrowFn(), Exc); + CGF.Builder.CreateUnreachable(); + + // Resume inserting where we started, but put the new cleanup + // handler in place. + if (PreviousInsertionBlock) + CGF.Builder.SetInsertPoint(PreviousInsertionBlock); + else + CGF.Builder.ClearInsertionPoint(); + + if (CGF.Exceptions) + CGF.setInvokeDest(CleanupHandler); +} + +llvm::BasicBlock *CodeGenFunction::getTerminateHandler() { + if (TerminateHandler) + return TerminateHandler; + + // We don't want to change anything at the current location, so + // save it aside and clear the insert point. + llvm::BasicBlock *SavedInsertBlock = Builder.GetInsertBlock(); + llvm::BasicBlock::iterator SavedInsertPoint = Builder.GetInsertPoint(); + Builder.ClearInsertionPoint(); + + llvm::Constant *Personality = getPersonalityFn(CGM); + llvm::Value *llvm_eh_exception = + CGM.getIntrinsic(llvm::Intrinsic::eh_exception); + llvm::Value *llvm_eh_selector = + CGM.getIntrinsic(llvm::Intrinsic::eh_selector); + + // Set up terminate handler + TerminateHandler = createBasicBlock("terminate.handler"); + EmitBlock(TerminateHandler); + llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + // We are required to emit this call to satisfy LLVM, even + // though we don't use the result. + llvm::Value *Args[] = { + Exc, Personality, + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1) + }; + Builder.CreateCall(llvm_eh_selector, &Args[0], llvm::array_endof(Args)); + llvm::CallInst *TerminateCall = + Builder.CreateCall(getTerminateFn(*this)); + TerminateCall->setDoesNotReturn(); + TerminateCall->setDoesNotThrow(); + Builder.CreateUnreachable(); + + // Restore the saved insertion state. + Builder.SetInsertPoint(SavedInsertBlock, SavedInsertPoint); + + return TerminateHandler; +} |
