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When an exception needs to be freed by calling __cxa_exception_free, make sure to stash away the exception pointer somewhere. 

This fixes an "Instruction does not dominate all uses!" verification error when compiling TableGen.

llvm-svn: 91084
This commit is contained in:
Anders Carlsson 2009-12-11 00:32:37 +00:00
parent ff141799fb
commit afd1edb52e
3 changed files with 44 additions and 12 deletions
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32
clang/lib/CodeGen/CGException.cpp
View File

@ -127,21 +127,24 @@ static llvm::Constant *getTerminateFn(CodeGenFunction &CGF) {
}
// CopyObject - Utility to copy an object. Calls copy constructor as necessary.
// N is casted to the right type.
static void CopyObject(CodeGenFunction &CGF, const Expr *E, llvm::Value *N) {
// 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(0);
const llvm::Type *ValuePtrTy = Value->getType()->getPointerTo();
CGF.Builder.CreateStore(Value, CGF.Builder.CreateBitCast(N, ValuePtrTy));
CGF.Builder.CreateStore(Value,
CGF.Builder.CreateBitCast(DestPtr, ValuePtrTy));
} 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);
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
@ -150,9 +153,9 @@ static void CopyObject(CodeGenFunction &CGF, const Expr *E, llvm::Value *N) {
if (CGF.Exceptions) {
CodeGenFunction::EHCleanupBlock Cleanup(CGF);
llvm::Constant *FreeExceptionFn = getFreeExceptionFn(CGF);
const llvm::Type *Int8PtrTy
= llvm::Type::getInt8PtrTy(CGF.getLLVMContext());
llvm::Value *ExceptionPtr = CGF.Builder.CreateBitCast(N, Int8PtrTy);
// Load the exception pointer.
llvm::Value *ExceptionPtr = CGF.Builder.CreateLoad(ExceptionPtrPtr);
CGF.Builder.CreateCall(FreeExceptionFn, ExceptionPtr);
}
@ -251,8 +254,13 @@ void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
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);
CopyObject(*this, E->getSubExpr(), ExceptionPtr, ExceptionPtrPtr);
// Now throw the exception.
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext());

6
clang/test/CodeGenCXX/eh.cpp
View File

@ -11,7 +11,9 @@ void test1() {
// CHECK: define void @_Z5test1v() nounwind {
// CHECK-NEXT:entry:
// CHECK-NEXT: %exception.ptr = alloca i8*
// CHECK-NEXT: %exception = call i8* @__cxa_allocate_exception(i64 8)
// CHECK-NEXT: store i8* %exception, i8** %exception.ptr
// CHECK-NEXT: %0 = bitcast i8* %exception to %struct.test1_D*
// CHECK-NEXT: %tmp = bitcast %struct.test1_D* %0 to i8*
// CHECK-NEXT: call void @llvm.memcpy.i64(i8* %tmp, i8* bitcast (%struct.test1_D* @d1 to i8*), i64 8, i32 8)
@ -32,7 +34,9 @@ void test2() {
// CHECK: define void @_Z5test2v() nounwind {
// CHECK-NEXT:entry:
// CHECK-NEXT: %exception.ptr = alloca i8*
// CHECK-NEXT: %exception = call i8* @__cxa_allocate_exception(i64 16)
// CHECK-NEXT: store i8* %exception, i8** %exception.ptr
// CHECK-NEXT: %0 = bitcast i8* %exception to %struct.test2_D*
// CHECK: invoke void @_ZN7test2_DC1ERKS_(%struct.test2_D* %0, %struct.test2_D* @d2)
// CHECK-NEXT: to label %invoke.cont unwind label %terminate.handler
@ -52,7 +56,9 @@ void test3() {
// CHECK: define void @_Z5test3v() nounwind {
// CHECK-NEXT: entry:
// CHECK-NEXT: %exception.ptr = alloca i8*
// CHECK-NEXT: %exception = call i8* @__cxa_allocate_exception(i64 8)
// CHECK-NEXT: store i8* %exception, i8** %exception.ptr
// CHECK-NEXT: %0 = bitcast i8* %exception to %struct.test3_D**
// CHECK-NEXT: store %struct.test3_D* null, %struct.test3_D** %0
// CHECK-NEXT: call void @__cxa_throw(i8* %exception, i8* bitcast (%1* @_ZTIPV7test3_D to i8*), i8* null) noreturn

18
clang/test/CodeGenCXX/exceptions.cpp Normal file
View File

@ -0,0 +1,18 @@
// RUN: clang-cc %s -triple=x86_64-apple-darwin10 -emit-llvm -o - -fexceptions
struct allocator {
allocator();
allocator(const allocator&);
~allocator();
};
void f();
void g(bool b, bool c) {
if (b) {
if (!c)
throw allocator();
return;
}
f();
}