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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
|
//===--- CGCXXRtti.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
//
// 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 RTTI descriptors.
//
//===----------------------------------------------------------------------===//
#include "CodeGenModule.h"
#include "clang/AST/RecordLayout.h"
using namespace clang;
using namespace CodeGen;
class RttiBuilder {
CodeGenModule &CGM; // Per-module state.
llvm::LLVMContext &VMContext;
const llvm::Type *Int8PtrTy;
llvm::SmallSet<const CXXRecordDecl *, 16> SeenVBase;
llvm::SmallSet<const CXXRecordDecl *, 32> SeenBase;
public:
RttiBuilder(CodeGenModule &cgm)
: CGM(cgm), VMContext(cgm.getModule().getContext()),
Int8PtrTy(llvm::Type::getInt8PtrTy(VMContext)) { }
/// BuildVtableRef - Build a reference to a vtable.
llvm::Constant *BuildVtableRef(const char *Name) {
// Build a descriptor for Name
llvm::Constant *GV = CGM.getModule().getGlobalVariable(Name);
if (GV)
GV = llvm::ConstantExpr::getBitCast(GV,
llvm::PointerType::get(Int8PtrTy, 0));
else {
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::ExternalLinkage;
GV = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy,
true, linktype, 0, Name);
}
llvm::Constant *C;
C = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), 2);
C = llvm::ConstantExpr::getInBoundsGetElementPtr(GV, &C, 1);
return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
}
llvm::Constant *BuildName(const CXXRecordDecl *RD) {
llvm::SmallString<256> OutName;
llvm::raw_svector_ostream Out(OutName);
mangleCXXRttiName(CGM.getMangleContext(),
CGM.getContext().getTagDeclType(RD), Out);
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::LinkOnceODRLinkage;
llvm::Constant *C;
C = llvm::ConstantArray::get(VMContext, Out.str().substr(4));
llvm::Constant *s = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
true, linktype, C,
Out.str());
s = llvm::ConstantExpr::getBitCast(s, Int8PtrTy);
return s;
};
/// - BuildFlags - Build a psABI __flags value for __vmi_class_type_info.
llvm::Constant *BuildFlags(int f) {
return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), f);
}
/// BuildBaseCount - Build a psABI __base_count value for
/// __vmi_class_type_info.
llvm::Constant *BuildBaseCount(unsigned c) {
return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), c);
}
llvm::Constant *BuildTypeRef(QualType Ty) {
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
llvm::Constant *C;
if (!CGM.getContext().getLangOptions().Rtti)
return llvm::Constant::getNullValue(Int8PtrTy);
llvm::SmallString<256> OutName;
llvm::raw_svector_ostream Out(OutName);
mangleCXXRtti(CGM.getMangleContext(), Ty, Out);
C = CGM.getModule().getGlobalVariable(Out.str());
if (C)
return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::ExternalLinkage;;
C = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy, true, linktype,
0, Out.str());
return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
}
llvm::Constant *Buildclass_type_infoRef(const CXXRecordDecl *RD) {
return BuildTypeRef(CGM.getContext().getTagDeclType(RD));
}
/// CalculateFlags - Calculate the flags for the __vmi_class_type_info
/// datastructure. 1 for non-diamond repeated inheritance, 2 for a dimond
/// shaped class.
int CalculateFlags(const CXXRecordDecl*RD) {
int flags = 0;
if (SeenBase.count(RD))
flags |= 1;
else
SeenBase.insert(RD);
for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
e = RD->bases_end(); i != e; ++i) {
const CXXRecordDecl *Base =
cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
if (i->isVirtual()) {
if (SeenVBase.count(Base))
flags |= 2;
else
SeenVBase.insert(Base);
}
flags |= CalculateFlags(Base);
}
return flags;
}
bool SimpleInheritance(const CXXRecordDecl *RD) {
if (RD->getNumBases() != 1)
return false;
CXXRecordDecl::base_class_const_iterator i = RD->bases_begin();
if (i->isVirtual())
return false;
if (i->getAccessSpecifier() != AS_public)
return false;
const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
const CXXRecordDecl *Base =
cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
if (Layout.getBaseClassOffset(Base) != 0)
return false;
return true;
}
llvm::Constant *Buildclass_type_info(const CXXRecordDecl *RD) {
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
llvm::Constant *C;
if (!CGM.getContext().getLangOptions().Rtti)
return llvm::Constant::getNullValue(Int8PtrTy);
llvm::SmallString<256> OutName;
llvm::raw_svector_ostream Out(OutName);
mangleCXXRtti(CGM.getMangleContext(), CGM.getContext().getTagDeclType(RD),
Out);
llvm::GlobalVariable *GV;
GV = CGM.getModule().getGlobalVariable(Out.str());
if (GV && !GV->isDeclaration())
return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::LinkOnceODRLinkage;
std::vector<llvm::Constant *> info;
bool simple = false;
if (RD->getNumBases() == 0)
C = BuildVtableRef("_ZTVN10__cxxabiv117__class_type_infoE");
else if (SimpleInheritance(RD)) {
simple = true;
C = BuildVtableRef("_ZTVN10__cxxabiv120__si_class_type_infoE");
} else
C = BuildVtableRef("_ZTVN10__cxxabiv121__vmi_class_type_infoE");
info.push_back(C);
info.push_back(BuildName(RD));
// If we have no bases, there are no more fields.
if (RD->getNumBases()) {
if (!simple) {
info.push_back(BuildFlags(CalculateFlags(RD)));
info.push_back(BuildBaseCount(RD->getNumBases()));
}
const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
e = RD->bases_end(); i != e; ++i) {
const CXXRecordDecl *Base =
cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
info.push_back(CGM.GenerateRttiRef(Base));
if (simple)
break;
int64_t offset;
if (!i->isVirtual())
offset = Layout.getBaseClassOffset(Base)/8;
else
offset = CGM.getVtableInfo().getVirtualBaseOffsetIndex(RD, Base);
offset <<= 8;
// Now set the flags.
offset += i->isVirtual() ? 1 : 0;;
offset += i->getAccessSpecifier() == AS_public ? 2 : 0;
const llvm::Type *LongTy =
CGM.getTypes().ConvertType(CGM.getContext().LongTy);
C = llvm::ConstantInt::get(LongTy, offset);
info.push_back(C);
}
}
std::vector<const llvm::Type *> Types(info.size());
for (unsigned i=0;
|
