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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
//===--- CGTemporaries.cpp - Emit LLVM Code for C++ temporaries -----------===//
//
// 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++ code generation of temporaries
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
using namespace clang;
using namespace CodeGen;
void CodeGenFunction::PushCXXTemporary(const CXXTemporary *Temporary,
llvm::Value *Ptr) {
assert((LiveTemporaries.empty() ||
LiveTemporaries.back().ThisPtr != Ptr ||
ConditionalBranchLevel) &&
"Pushed the same temporary twice; AST is likely wrong");
llvm::BasicBlock *DtorBlock = createBasicBlock("temp.dtor");
llvm::AllocaInst *CondPtr = 0;
// Check if temporaries need to be conditional. If so, we'll create a
// condition boolean, initialize it to 0 and
if (ConditionalBranchLevel != 0) {
CondPtr = CreateTempAlloca(llvm::Type::getInt1Ty(VMContext), "cond");
// Initialize it to false. This initialization takes place right after
// the alloca insert point.
InitTempAlloca(CondPtr, llvm::ConstantInt::getFalse(VMContext));
// Now set it to true.
Builder.CreateStore(llvm::ConstantInt::getTrue(VMContext), CondPtr);
}
LiveTemporaries.push_back(CXXLiveTemporaryInfo(Temporary, Ptr, DtorBlock,
CondPtr));
PushCleanupBlock(DtorBlock);
if (Exceptions) {
const CXXLiveTemporaryInfo& Info = LiveTemporaries.back();
llvm::BasicBlock *CondEnd = 0;
EHCleanupBlock Cleanup(*this);
// If this is a conditional temporary, we need to check the condition
// boolean and only call the destructor if it's true.
if (Info.CondPtr) {
llvm::BasicBlock *CondBlock = createBasicBlock("cond.dtor.call");
CondEnd = createBasicBlock("cond.dtor.end");
llvm::Value *Cond = Builder.CreateLoad(Info.CondPtr);
Builder.CreateCondBr(Cond, CondBlock, CondEnd);
EmitBlock(CondBlock);
}
EmitCXXDestructorCall(Info.Temporary->getDestructor(),
Dtor_Complete, /*ForVirtualBase=*/false,
Info.ThisPtr);
if (CondEnd) {
// Reset the condition. to false.
Builder.CreateStore(llvm::ConstantInt::getFalse(VMContext), Info.CondPtr);
EmitBlock(CondEnd);
}
}
}
void CodeGenFunction::PopCXXTemporary() {
const CXXLiveTemporaryInfo& Info = LiveTemporaries.back();
CleanupBlockInfo CleanupInfo = PopCleanupBlock();
assert(CleanupInfo.CleanupBlock == Info.DtorBlock &&
"Cleanup block mismatch!");
assert(!CleanupInfo.SwitchBlock &&
"Should not have a switch block for temporary cleanup!");
assert(!CleanupInfo.EndBlock &&
"Should not have an end block for temporary cleanup!");
llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
if (CurBB && !CurBB->getTerminator() &&
Info.DtorBlock->getNumUses() == 0) {
CurBB->getInstList().splice(CurBB->end(), Info.DtorBlock->getInstList());
delete Info.DtorBlock;
} else
EmitBlock(Info.DtorBlock);
llvm::BasicBlock *CondEnd = 0;
// If this is a conditional temporary, we need to check the condition
// boolean and only call the destructor if it's true.
if (Info.CondPtr) {
llvm::BasicBlock *CondBlock = createBasicBlock("cond.dtor.call");
CondEnd = createBasicBlock("cond.dtor.end");
llvm::Value *Cond = Builder.CreateLoad(Info.CondPtr);
Builder.CreateCondBr(Cond, CondBlock, CondEnd);
EmitBlock(CondBlock);
}
EmitCXXDestructorCall(Info.Temporary->getDestructor(),
Dtor_Complete, /*ForVirtualBase=*/false, Info.ThisPtr);
if (CondEnd) {
// Reset the condition. to false.
Builder.CreateStore(llvm::ConstantInt::getFalse(VMContext), Info.CondPtr);
EmitBlock(CondEnd);
}
LiveTemporaries.pop_back();
}
RValue
CodeGenFunction::EmitCXXExprWithTemporaries(const CXXExprWithTemporaries *E,
llvm::Value *AggLoc,
bool IsAggLocVolatile,
bool IsInitializer) {
// Keep track of the current cleanup stack depth.
size_t CleanupStackDepth = CleanupEntries.size();
(void) CleanupStackDepth;
RValue RV;
{
CXXTemporariesCleanupScope Scope(*this);
RV = EmitAnyExpr(E->getSubExpr(), AggLoc, IsAggLocVolatile,
/*IgnoreResult=*/false, IsInitializer);
}
assert(CleanupEntries.size() == CleanupStackDepth &&
"Cleanup size mismatch!");
return RV;
}
LValue CodeGenFunction::EmitCXXExprWithTemporariesLValue(
const CXXExprWithTemporaries *E) {
// Keep track of the current cleanup stack depth.
size_t CleanupStackDepth = CleanupEntries.size();
(void) CleanupStackDepth;
unsigned OldNumLiveTemporaries = LiveTemporaries.size();
LValue LV = EmitLValue(E->getSubExpr());
// Pop temporaries.
while (LiveTemporaries.size() > OldNumLiveTemporaries)
PopCXXTemporary();
assert(CleanupEntries.size() == CleanupStackDepth &&
"Cleanup size mismatch!");
return LV;
}
|
