1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
//===--- 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 "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 *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");
}
void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
// FIXME: Handle rethrows.
if (!E->getSubExpr()) {
ErrorUnsupported(E, "rethrow expression");
return;
}
QualType ThrowType = E->getSubExpr()->getType();
// FIXME: We only handle non-class types for now.
if (ThrowType->isRecordType()) {
ErrorUnsupported(E, "throw expression");
return;
}
// FIXME: Handle cleanup.
if (!CleanupEntries.empty()){
ErrorUnsupported(E, "throw expression");
return;
}
// 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");
// Store the throw exception in the exception object.
if (!hasAggregateLLVMType(ThrowType)) {
llvm::Value *Value = EmitScalarExpr(E->getSubExpr());
const llvm::Type *ValuePtrTy = Value->getType()->getPointerTo(0);
Builder.CreateStore(Value, Builder.CreateBitCast(ExceptionPtr, ValuePtrTy));
} else {
// FIXME: Handle complex and aggregate expressions.
ErrorUnsupported(E, "throw expression");
}
// Now throw the exception.
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(getLLVMContext());
llvm::SmallString<256> OutName;
llvm::raw_svector_ostream Out(OutName);
mangleCXXRtti(CGM.getMangleContext(), ThrowType, Out);
// FIXME: Is it OK to use CreateRuntimeVariable for this?
llvm::Constant *TypeInfo =
CGM.CreateRuntimeVariable(llvm::Type::getInt8Ty(getLLVMContext()),
OutName.c_str());
llvm::Constant *Dtor = llvm::Constant::getNullValue(Int8PtrTy);
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();
}
|
