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
|
//===- ModuleSymbolTable.cpp - symbol table for in-memory IR --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This class represents a symbol table built from in-memory IR. It provides
// access to GlobalValues and should only be used if such access is required
// (e.g. in the LTO implementation).
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/ModuleSymbolTable.h"
#include "RecordStreamer.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCParser/MCAsmParser.h"
#include "llvm/MC/MCParser/MCTargetAsmParser.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <memory>
#include <string>
using namespace llvm;
using namespace object;
void ModuleSymbolTable::addModule(Module *M) {
if (FirstMod)
assert(FirstMod->getTargetTriple() == M->getTargetTriple());
else
FirstMod = M;
for (GlobalValue &GV : M->global_values())
SymTab.push_back(&GV);
CollectAsmSymbols(*M, [this](StringRef Name, BasicSymbolRef::Flags Flags) {
SymTab.push_back(new (AsmSymbols.Allocate())
AsmSymbol(std::string(Name), Flags));
});
}
static void
initializeRecordStreamer(const Module &M,
function_ref<void(RecordStreamer &)> Init) {
StringRef InlineAsm = M.getModuleInlineAsm();
if (InlineAsm.empty())
return;
std::string Err;
const Triple TT(M.getTargetTriple());
const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
assert(T && T->hasMCAsmParser());
std::unique_ptr<MCRegisterInfo> MRI(T->createMCRegInfo(TT.str()));
if (!MRI)
return;
MCTargetOptions MCOptions;
std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, TT.str(), MCOptions));
if (!MAI)
return;
std::unique_ptr<MCSubtargetInfo> STI(
T->createMCSubtargetInfo(TT.str(), "", ""));
if (!STI)
return;
std::unique_ptr<MCInstrInfo> MCII(T->createMCInstrInfo());
if (!MCII)
return;
std::unique_ptr<MemoryBuffer> Buffer(MemoryBuffer::getMemBuffer(InlineAsm));
SourceMgr SrcMgr;
SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
MCContext MCCtx(TT, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
std::unique_ptr<MCObjectFileInfo> MOFI(
T->createMCObjectFileInfo(MCCtx, /*PIC=*/false));
MOFI->setSDKVersion(M.getSDKVersion());
MCCtx.setObjectFileInfo(MOFI.get());
RecordStreamer Streamer(MCCtx, M);
T->createNullTargetStreamer(Streamer);
std::unique_ptr<MCAsmParser> Parser(
createMCAsmParser(SrcMgr, MCCtx, Streamer, *MAI));
std::unique_ptr<MCTargetAsmParser> TAP(
T->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
if (!TAP)
return;
// Module-level inline asm is assumed to use At&t syntax (see
// AsmPrinter::doInitialization()).
Parser->setAssemblerDialect(InlineAsm::AD_ATT);
Parser->setTargetParser(*TAP);
if (Parser->Run(false))
return;
Init(Streamer);
}
void ModuleSymbolTable::CollectAsmSymbols(
const Module &M,
function_ref<void(StringRef, BasicSymbolRef::Flags)> AsmSymbol) {
initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
Streamer.flushSymverDirectives();
for (auto &KV : Streamer) {
StringRef Key = KV.first();
RecordStreamer::State Value = KV.second;
// FIXME: For now we just assume that all asm symbols are executable.
uint32_t Res = BasicSymbolRef::SF_Executable;
switch (Value) {
case RecordStreamer::NeverSeen:
llvm_unreachable("NeverSeen should have been replaced earlier");
case RecordStreamer::DefinedGlobal:
Res |= BasicSymbolRef::SF_Global;
break;
case RecordStreamer::Defined:
break;
case RecordStreamer::Global:
case RecordStreamer::Used:
Res |= BasicSymbolRef::SF_Undefined;
Res |= BasicSymbolRef::SF_Global;
break;
case RecordStreamer::DefinedWeak:
Res |= BasicSymbolRef::SF_Weak;
Res |= BasicSymbolRef::SF_Global;
break;
case RecordStreamer::UndefinedWeak:
Res |= BasicSymbolRef::SF_Weak;
Res |= BasicSymbolRef::SF_Undefined;
}
AsmSymbol(Key, BasicSymbolRef::Flags(Res));
}
});
}
void ModuleSymbolTable::CollectAsmSymvers(
const Module &M, function_ref<void(StringRef, StringRef)> AsmSymver) {
initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
for (auto &KV : Streamer.symverAliases())
for (auto &Alias : KV.second)
AsmSymver(KV.first->getName(), Alias);
});
}
void ModuleSymbolTable::printSymbolName(raw_ostream &OS, Symbol S) const {
if (S.is<AsmSymbol *>()) {
OS << S.get<AsmSymbol *>()->first;
return;
}
auto *GV = S.get<GlobalValue *>();
if (GV->hasDLLImportStorageClass())
OS << "__imp_";
Mang.getNameWithPrefix(OS, GV, false);
}
uint32_t ModuleSymbolTable::getSymbolFlags(Symbol S) const {
if (S.is<AsmSymbol *>())
return S.get<AsmSymbol *>()->second;
auto *GV = S.get<GlobalValue *>();
uint32_t Res = BasicSymbolRef::SF_None;
if (GV->isDeclarationForLinker())
Res |= BasicSymbolRef::SF_Undefined;
else if (GV->hasHiddenVisibility() && !GV->hasLocalLinkage())
Res |= BasicSymbolRef::SF_Hidden;
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
if (GVar->isConstant())
Res |= BasicSymbolRef::SF_Const;
}
if (dyn_cast_or_null<Function>(GV->getBaseObject()))
Res |= BasicSymbolRef::SF_Executable;
if (isa<GlobalAlias>(GV))
Res |= BasicSymbolRef::SF_Indirect;
if (GV->hasPrivateLinkage())
Res |= BasicSymbolRef::SF_FormatSpecific;
if (!GV->hasLocalLinkage())
Res |= BasicSymbolRef::SF_Global;
if (GV->hasCommonLinkage())
Res |= BasicSymbolRef::SF_Common;
if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage() ||
GV->hasExternalWeakLinkage())
Res |= BasicSymbolRef::SF_Weak;
if (GV->getName().startswith("llvm."))
Res |= BasicSymbolRef::SF_FormatSpecific;
else if (auto *Var = dyn_cast<GlobalVariable>(GV)) {
if (Var->getSection() == "llvm.metadata")
Res |= BasicSymbolRef::SF_FormatSpecific;
}
return Res;
}
|
