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|
//===--- 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");
}
static llvm::Constant *getUnwindResumeOrRethrowFn(CodeGenFunction &CGF) {
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);
if (CGF.CGM.getLangOptions().SjLjExceptions)
return CGF.CGM.CreateRuntimeFunction(FTy, "_Unwind_SjLj_Resume");
return CGF.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, "_ZSt9terminatev");
}
// CopyObject - Utility to copy an object. Calls copy constructor as necessary.
// DestPtr is casted to the right type.
static void CopyObject(CodeGenFunction &CGF, const Expr *E,
llvm::Value *DestPtr, llvm::Value *ExceptionPtrPtr) {
QualType ObjectType = E->getType();
// Store the throw exception in the exception object.
if (!CGF.hasAggregateLLVMType(ObjectType)) {
llvm::Value *Value = CGF.EmitScalarExpr(E);
const llvm::Type *ValuePtrTy = Value->getType()->getPointerTo();
CGF.Builder.CreateStore(Value,
CGF.Builder.CreateBitCast(DestPtr, ValuePtrTy));
} else {
const llvm::Type *Ty = CGF.ConvertType(ObjectType)->getPointerTo();
const CXXRecordDecl *RD =
cast<CXXRecordDecl>(ObjectType->getAs<RecordType>()->getDecl());
llvm::Value *This = CGF.Builder.CreateBitCast(DestPtr, Ty);
if (RD->hasTrivialCopyConstructor()) {
CGF.EmitAggExpr(E, This, false);
} else if (CXXConstructorDecl *CopyCtor
= RD->getCopyConstructor(CGF.getContext(), 0)) {
llvm::Value *CondPtr = 0;
if (CGF.Exceptions) {
CodeGenFunction::EHCleanupBlock Cleanup(CGF);
llvm::Constant *FreeExceptionFn = getFreeExceptionFn(CGF);
llvm::BasicBlock *CondBlock = CGF.createBasicBlock("cond.free");
llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
CondPtr = CGF.CreateTempAlloca(llvm::Type::getInt1Ty(CGF.getLLVMContext()),
"doEHfree");
CGF.Builder.CreateCondBr(CGF.Builder.CreateLoad(CondPtr),
CondBlock, Cont);
CGF.EmitBlock(CondBlock);
// Load the exception pointer.
llvm::Value *ExceptionPtr = CGF.Builder.CreateLoad(ExceptionPtrPtr);
CGF.Builder.CreateCall(FreeExceptionFn, ExceptionPtr);
CGF.EmitBlock(Cont);
}
if (CondPtr)
CGF.Builder.CreateStore(llvm::ConstantInt::getTrue(CGF.getLLVMContext()),
CondPtr);
llvm::Value *Src = CGF.EmitLValue(E).getAddress();
if (CondPtr)
CGF.Builder.CreateStore(llvm::ConstantInt::getFalse(CGF.getLLVMContext()),
CondPtr);
llvm::BasicBlock *TerminateHandler = CGF.getTerminateHandler();
llvm::BasicBlock *PrevLandingPad = CGF.getInvokeDest();
CGF.setInvokeDest(TerminateHandler);
// 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);
CGF.setInvokeDest(PrevLandingPad);
} else
llvm_unreachable("uncopyable object");
}
}
// 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().getTypeSize(ThrowType) / 8;
llvm::Constant *AllocExceptionFn = getAllocateExceptionFn(*this);
llvm::Value *ExceptionPtr =
Builder.CreateCall(AllocExceptionFn,
llvm::ConstantInt::get(SizeTy, TypeSize),
"exception");
llvm::Value *ExceptionPtrPtr =
CreateTempAlloca(ExceptionPtr->getType(), "exception.ptr");
Builder.CreateStore(ExceptionPtr, ExceptionPtrPtr);
CopyObject(*this, E->getSubExpr(), ExceptionPtr, ExceptionPtrPtr);
// Now throw the exception.
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext());
llvm::Constant *TypeInfo = CGM.GetAddrOfRTTIDescriptor(ThrowType);
llvm::Constant *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 =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty
(VMContext),
true),
"__gxx_personality_v0");
Personality = llvm::ConstantExpr::getBitCast(Personality, PtrToInt8Ty);
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);
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(*this),
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 =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty
(VMContext),
true),
"__gxx_personality_v0");
Personality = llvm::ConstantExpr::getBitCast(Personality, PtrToInt8Ty);
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());
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(*this), Cont,
getInvokeDest(),
Builder.CreateLoad(RethrowPtr));
EmitBlock(Cont);
} else
Builder.CreateCall(getUnwindResumeOrRethrowFn(*this),
Builder.CreateLoad(RethrowPtr));
Builder.CreateUnreachable();
EmitBlock(FinallyEnd);
}
CodeGenFunction::EHCleanupBlock::~EHCleanupBlock() {
llvm::BasicBlock *Cont1 = CGF.createBasicBlock("cont");
CGF.EmitBranch(Cont1);
CGF.setInvokeDest(PreviousInvokeDest);
CGF.EmitBlock(CleanupHandler);
llvm::Constant *Personality =
CGF.CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty
(CGF.VMContext),
true),
"__gxx_personality_v0");
Personality = llvm::ConstantExpr::getBitCast(Personality, CGF.PtrToInt8Ty);
llvm::Value *llvm_eh_exception =
CGF.CGM.getIntrinsic(llvm::Intrinsic::eh_exception);
llvm::Value *llvm_eh_selector =
CGF.CGM.getIntrinsic(llvm::Intrinsic::eh_selector);
llvm::Value *Exc = CGF.Builder.CreateCall(llvm_eh_exception, "exc");
const llvm::IntegerType *Int8Ty;
const llvm::PointerType *PtrToInt8Ty;
Int8Ty = llvm::Type::getInt8Ty(CGF.VMContext);
// C string type. Used in lots of places.
PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
llvm::Constant *Null = llvm::ConstantPointerNull::get(PtrToInt8Ty);
llvm::Value *Args[] = { Exc, Personality, Null };
CGF.Builder.CreateCall(llvm_eh_selector, &Args[0], llvm::array_endof(Args));
CGF.EmitBlock(CleanupEntryBB);
CGF.EmitBlock(Cont1);
if (CGF.getInvokeDest()) {
llvm::BasicBlock *Cont = CGF.createBasicBlock("invoke.cont");
CGF.Builder.CreateInvoke(getUnwindResumeOrRethrowFn(CGF), Cont,
CGF.getInvokeDest(), Exc);
CGF.EmitBlock(Cont);
} else
CGF.Builder.CreateCall(getUnwindResumeOrRethrowFn(CGF), Exc);
CGF.Builder.CreateUnreachable();
CGF.EmitBlock(Cont);
if (CGF.Exceptions)
CGF.setInvokeDest(CleanupHandler);
}
llvm::BasicBlock *CodeGenFunction::getTerminateHandler() {
if (TerminateHandler)
return TerminateHandler;
llvm::BasicBlock *Cont = 0;
if (HaveInsertPoint()) {
Cont = createBasicBlock("cont");
EmitBranch(Cont);
}
llvm::Constant *Personality =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty
(VMContext),
true),
"__gxx_personality_v0");
Personality = llvm::ConstantExpr::getBitCast(Personality, PtrToInt8Ty);
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();
// Clear the insertion point to indicate we are in unreachable code.
Builder.ClearInsertionPoint();
if (Cont)
EmitBlock(Cont);
return TerminateHandler;
}
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