Bug Summary

File:lib/Object/IRObjectFile.cpp
Location:line 186, column 10
Description:Assigned value is garbage or undefined

Annotated Source Code

1//===- IRObjectFile.cpp - IR object file implementation ---------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Part of the IRObjectFile class implementation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Object/IRObjectFile.h"
15#include "RecordStreamer.h"
16#include "llvm/Bitcode/ReaderWriter.h"
17#include "llvm/IR/LLVMContext.h"
18#include "llvm/IR/GVMaterializer.h"
19#include "llvm/IR/Mangler.h"
20#include "llvm/IR/Module.h"
21#include "llvm/MC/MCRegisterInfo.h"
22#include "llvm/MC/MCAsmInfo.h"
23#include "llvm/MC/MCContext.h"
24#include "llvm/MC/MCInstrInfo.h"
25#include "llvm/MC/MCObjectFileInfo.h"
26#include "llvm/MC/MCTargetAsmParser.h"
27#include "llvm/MC/MCParser/MCAsmParser.h"
28#include "llvm/Object/ObjectFile.h"
29#include "llvm/Support/MemoryBuffer.h"
30#include "llvm/Support/SourceMgr.h"
31#include "llvm/Support/TargetRegistry.h"
32#include "llvm/Support/raw_ostream.h"
33using namespace llvm;
34using namespace object;
35
36IRObjectFile::IRObjectFile(MemoryBufferRef Object, std::unique_ptr<Module> Mod)
37 : SymbolicFile(Binary::ID_IR, Object), M(std::move(Mod)) {
38 // If we have a DataLayout, setup a mangler.
39 const DataLayout *DL = M->getDataLayout();
40 if (!DL)
41 return;
42
43 Mang.reset(new Mangler(DL));
44
45 const std::string &InlineAsm = M->getModuleInlineAsm();
46 if (InlineAsm.empty())
47 return;
48
49 StringRef Triple = M->getTargetTriple();
50 std::string Err;
51 const Target *T = TargetRegistry::lookupTarget(Triple, Err);
52 if (!T)
53 return;
54
55 std::unique_ptr<MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
56 if (!MRI)
57 return;
58
59 std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, Triple));
60 if (!MAI)
61 return;
62
63 std::unique_ptr<MCSubtargetInfo> STI(
64 T->createMCSubtargetInfo(Triple, "", ""));
65 if (!STI)
66 return;
67
68 std::unique_ptr<MCInstrInfo> MCII(T->createMCInstrInfo());
69 if (!MCII)
70 return;
71
72 MCObjectFileInfo MOFI;
73 MCContext MCCtx(MAI.get(), MRI.get(), &MOFI);
74 MOFI.InitMCObjectFileInfo(Triple, Reloc::Default, CodeModel::Default, MCCtx);
75 std::unique_ptr<RecordStreamer> Streamer(new RecordStreamer(MCCtx));
76
77 std::unique_ptr<MemoryBuffer> Buffer(MemoryBuffer::getMemBuffer(InlineAsm));
78 SourceMgr SrcMgr;
79 SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
80 std::unique_ptr<MCAsmParser> Parser(
81 createMCAsmParser(SrcMgr, MCCtx, *Streamer, *MAI));
82
83 MCTargetOptions MCOptions;
84 std::unique_ptr<MCTargetAsmParser> TAP(
85 T->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
86 if (!TAP)
87 return;
88
89 Parser->setTargetParser(*TAP);
90 if (Parser->Run(false))
91 return;
92
93 for (auto &KV : *Streamer) {
94 StringRef Key = KV.first();
95 RecordStreamer::State Value = KV.second;
96 uint32_t Res = BasicSymbolRef::SF_None;
97 switch (Value) {
98 case RecordStreamer::NeverSeen:
99 llvm_unreachable("foo")::llvm::llvm_unreachable_internal("foo", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/Object/IRObjectFile.cpp"
, 99);
100 case RecordStreamer::DefinedGlobal:
101 Res |= BasicSymbolRef::SF_Global;
102 break;
103 case RecordStreamer::Defined:
104 break;
105 case RecordStreamer::Global:
106 case RecordStreamer::Used:
107 Res |= BasicSymbolRef::SF_Undefined;
108 Res |= BasicSymbolRef::SF_Global;
109 break;
110 }
111 AsmSymbols.push_back(
112 std::make_pair<std::string, uint32_t>(Key, std::move(Res)));
113 }
114}
115
116IRObjectFile::~IRObjectFile() {
117 }
118
119static GlobalValue *getGV(DataRefImpl &Symb) {
120 if ((Symb.p & 3) == 3)
121 return nullptr;
122
123 return reinterpret_cast<GlobalValue*>(Symb.p & ~uintptr_t(3));
124}
125
126static uintptr_t skipEmpty(Module::const_alias_iterator I, const Module &M) {
127 if (I == M.alias_end())
128 return 3;
129 const GlobalValue *GV = &*I;
130 return reinterpret_cast<uintptr_t>(GV) | 2;
131}
132
133static uintptr_t skipEmpty(Module::const_global_iterator I, const Module &M) {
134 if (I == M.global_end())
135 return skipEmpty(M.alias_begin(), M);
136 const GlobalValue *GV = &*I;
137 return reinterpret_cast<uintptr_t>(GV) | 1;
138}
139
140static uintptr_t skipEmpty(Module::const_iterator I, const Module &M) {
141 if (I == M.end())
142 return skipEmpty(M.global_begin(), M);
143 const GlobalValue *GV = &*I;
144 return reinterpret_cast<uintptr_t>(GV) | 0;
145}
146
147static unsigned getAsmSymIndex(DataRefImpl Symb) {
148 assert((Symb.p & uintptr_t(3)) == 3)(((Symb.p & uintptr_t(3)) == 3) ? static_cast<void>
(0) : __assert_fail ("(Symb.p & uintptr_t(3)) == 3", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/Object/IRObjectFile.cpp"
, 148, __PRETTY_FUNCTION__));
149 uintptr_t Index = Symb.p & ~uintptr_t(3);
150 Index >>= 2;
151 return Index;
152}
153
154void IRObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
155 const GlobalValue *GV = getGV(Symb);
156 uintptr_t Res;
1
'Res' declared without an initial value
→
157
158 switch (Symb.p & 3) {
2
←
'Default' branch taken. Execution continues on line 186
→
159 case 0: {
160 Module::const_iterator Iter(static_cast<const Function*>(GV));
161 ++Iter;
162 Res = skipEmpty(Iter, *M);
163 break;
164 }
165 case 1: {
166 Module::const_global_iterator Iter(static_cast<const GlobalVariable*>(GV));
167 ++Iter;
168 Res = skipEmpty(Iter, *M);
169 break;
170 }
171 case 2: {
172 Module::const_alias_iterator Iter(static_cast<const GlobalAlias*>(GV));
173 ++Iter;
174 Res = skipEmpty(Iter, *M);
175 break;
176 }
177 case 3: {
178 unsigned Index = getAsmSymIndex(Symb);
179 assert(Index < AsmSymbols.size())((Index < AsmSymbols.size()) ? static_cast<void> (0)
: __assert_fail ("Index < AsmSymbols.size()", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/Object/IRObjectFile.cpp"
, 179, __PRETTY_FUNCTION__));
180 ++Index;
181 Res = (Index << 2) | 3;
182 break;
183 }
184 }
185
186 Symb.p = Res;
3
←
Assigned value is garbage or undefined
187}
188
189std::error_code IRObjectFile::printSymbolName(raw_ostream &OS,
190 DataRefImpl Symb) const {
191 const GlobalValue *GV = getGV(Symb);
192 if (!GV) {
193 unsigned Index = getAsmSymIndex(Symb);
194 assert(Index <= AsmSymbols.size())((Index <= AsmSymbols.size()) ? static_cast<void> (0
) : __assert_fail ("Index <= AsmSymbols.size()", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/Object/IRObjectFile.cpp"
, 194, __PRETTY_FUNCTION__));
195 OS << AsmSymbols[Index].first;
196 return object_error::success;;
197 }
198
199 if (Mang)
200 Mang->getNameWithPrefix(OS, GV, false);
201 else
202 OS << GV->getName();
203
204 return object_error::success;
205}
206
207uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
208 const GlobalValue *GV = getGV(Symb);
209
210 if (!GV) {
211 unsigned Index = getAsmSymIndex(Symb);
212 assert(Index <= AsmSymbols.size())((Index <= AsmSymbols.size()) ? static_cast<void> (0
) : __assert_fail ("Index <= AsmSymbols.size()", "/tmp/buildd/llvm-toolchain-snapshot-3.6~svn224240/lib/Object/IRObjectFile.cpp"
, 212, __PRETTY_FUNCTION__));
213 return AsmSymbols[Index].second;
214 }
215
216 uint32_t Res = BasicSymbolRef::SF_None;
217 if (GV->isDeclarationForLinker())
218 Res |= BasicSymbolRef::SF_Undefined;
219 if (GV->hasPrivateLinkage())
220 Res |= BasicSymbolRef::SF_FormatSpecific;
221 if (!GV->hasLocalLinkage())
222 Res |= BasicSymbolRef::SF_Global;
223 if (GV->hasCommonLinkage())
224 Res |= BasicSymbolRef::SF_Common;
225 if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage())
226 Res |= BasicSymbolRef::SF_Weak;
227
228 if (GV->getName().startswith("llvm."))
229 Res |= BasicSymbolRef::SF_FormatSpecific;
230 else if (auto *Var = dyn_cast<GlobalVariable>(GV)) {
231 if (Var->getSection() == StringRef("llvm.metadata"))
232 Res |= BasicSymbolRef::SF_FormatSpecific;
233 }
234
235 return Res;
236}
237
238GlobalValue *IRObjectFile::getSymbolGV(DataRefImpl Symb) { return getGV(Symb); }
239
240std::unique_ptr<Module> IRObjectFile::takeModule() { return std::move(M); }
241
242basic_symbol_iterator IRObjectFile::symbol_begin_impl() const {
243 Module::const_iterator I = M->begin();
244 DataRefImpl Ret;
245 Ret.p = skipEmpty(I, *M);
246 return basic_symbol_iterator(BasicSymbolRef(Ret, this));
247}
248
249basic_symbol_iterator IRObjectFile::symbol_end_impl() const {
250 DataRefImpl Ret;
251 uint64_t NumAsm = AsmSymbols.size();
252 NumAsm <<= 2;
253 Ret.p = 3 | NumAsm;
254 return basic_symbol_iterator(BasicSymbolRef(Ret, this));
255}
256
257ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInObject(const ObjectFile &Obj) {
258 for (const SectionRef &Sec : Obj.sections()) {
259 StringRef SecName;
260 if (std::error_code EC = Sec.getName(SecName))
261 return EC;
262 if (SecName == ".llvmbc") {
263 StringRef SecContents;
264 if (std::error_code EC = Sec.getContents(SecContents))
265 return EC;
266 return MemoryBufferRef(SecContents, Obj.getFileName());
267 }
268 }
269
270 return object_error::bitcode_section_not_found;
271}
272
273ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInMemBuffer(MemoryBufferRef Object) {
274 sys::fs::file_magic Type = sys::fs::identify_magic(Object.getBuffer());
275 switch (Type) {
276 case sys::fs::file_magic::bitcode:
277 return Object;
278 case sys::fs::file_magic::elf_relocatable:
279 case sys::fs::file_magic::macho_object:
280 case sys::fs::file_magic::coff_object: {
281 ErrorOr<std::unique_ptr<ObjectFile>> ObjFile =
282 ObjectFile::createObjectFile(Object, Type);
283 if (!ObjFile)
284 return ObjFile.getError();
285 return findBitcodeInObject(*ObjFile->get());
286 }
287 default:
288 return object_error::invalid_file_type;
289 }
290}
291
292ErrorOr<std::unique_ptr<IRObjectFile>>
293llvm::object::IRObjectFile::create(MemoryBufferRef Object,
294 LLVMContext &Context) {
295 ErrorOr<MemoryBufferRef> BCOrErr = findBitcodeInMemBuffer(Object);
296 if (!BCOrErr)
297 return BCOrErr.getError();
298
299 std::unique_ptr<MemoryBuffer> Buff(
300 MemoryBuffer::getMemBuffer(BCOrErr.get(), false));
301
302 ErrorOr<Module *> MOrErr = getLazyBitcodeModule(std::move(Buff), Context);
303 if (std::error_code EC = MOrErr.getError())
304 return EC;
305
306 std::unique_ptr<Module> M(MOrErr.get());
307 return llvm::make_unique<IRObjectFile>(Object, std::move(M));
308}