IRObjectFile.cpp revision 280031 
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/GVMaterializer.h"
18#include "llvm/IR/LLVMContext.h"
19#include "llvm/IR/Mangler.h"
20#include "llvm/IR/Module.h"
21#include "llvm/MC/MCAsmInfo.h"
22#include "llvm/MC/MCContext.h"
23#include "llvm/MC/MCInstrInfo.h"
24#include "llvm/MC/MCObjectFileInfo.h"
25#include "llvm/MC/MCParser/MCAsmParser.h"
26#include "llvm/MC/MCRegisterInfo.h"
27#include "llvm/MC/MCTargetAsmParser.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");
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);
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;
157
158  switch (Symb.p & 3) {
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());
180    ++Index;
181    Res = (Index << 2) | 3;
182    break;
183  }
184  default:
185    llvm_unreachable("unreachable case");
186  }
187
188  Symb.p = Res;
189}
190
191std::error_code IRObjectFile::printSymbolName(raw_ostream &OS,
192                                              DataRefImpl Symb) const {
193  const GlobalValue *GV = getGV(Symb);
194  if (!GV) {
195    unsigned Index = getAsmSymIndex(Symb);
196    assert(Index <= AsmSymbols.size());
197    OS << AsmSymbols[Index].first;
198    return object_error::success;;
199  }
200
201  if (Mang)
202    Mang->getNameWithPrefix(OS, GV, false);
203  else
204    OS << GV->getName();
205
206  return object_error::success;
207}
208
209uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
210  const GlobalValue *GV = getGV(Symb);
211
212  if (!GV) {
213    unsigned Index = getAsmSymIndex(Symb);
214    assert(Index <= AsmSymbols.size());
215    return AsmSymbols[Index].second;
216  }
217
218  uint32_t Res = BasicSymbolRef::SF_None;
219  if (GV->isDeclarationForLinker())
220    Res |= BasicSymbolRef::SF_Undefined;
221  if (GV->hasPrivateLinkage())
222    Res |= BasicSymbolRef::SF_FormatSpecific;
223  if (!GV->hasLocalLinkage())
224    Res |= BasicSymbolRef::SF_Global;
225  if (GV->hasCommonLinkage())
226    Res |= BasicSymbolRef::SF_Common;
227  if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage())
228    Res |= BasicSymbolRef::SF_Weak;
229
230  if (GV->getName().startswith("llvm."))
231    Res |= BasicSymbolRef::SF_FormatSpecific;
232  else if (auto *Var = dyn_cast<GlobalVariable>(GV)) {
233    if (Var->getSection() == StringRef("llvm.metadata"))
234      Res |= BasicSymbolRef::SF_FormatSpecific;
235  }
236
237  return Res;
238}
239
240GlobalValue *IRObjectFile::getSymbolGV(DataRefImpl Symb) { return getGV(Symb); }
241
242std::unique_ptr<Module> IRObjectFile::takeModule() { return std::move(M); }
243
244basic_symbol_iterator IRObjectFile::symbol_begin_impl() const {
245  Module::const_iterator I = M->begin();
246  DataRefImpl Ret;
247  Ret.p = skipEmpty(I, *M);
248  return basic_symbol_iterator(BasicSymbolRef(Ret, this));
249}
250
251basic_symbol_iterator IRObjectFile::symbol_end_impl() const {
252  DataRefImpl Ret;
253  uint64_t NumAsm = AsmSymbols.size();
254  NumAsm <<= 2;
255  Ret.p = 3 | NumAsm;
256  return basic_symbol_iterator(BasicSymbolRef(Ret, this));
257}
258
259ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInObject(const ObjectFile &Obj) {
260  for (const SectionRef &Sec : Obj.sections()) {
261    StringRef SecName;
262    if (std::error_code EC = Sec.getName(SecName))
263      return EC;
264    if (SecName == ".llvmbc") {
265      StringRef SecContents;
266      if (std::error_code EC = Sec.getContents(SecContents))
267        return EC;
268      return MemoryBufferRef(SecContents, Obj.getFileName());
269    }
270  }
271
272  return object_error::bitcode_section_not_found;
273}
274
275ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInMemBuffer(MemoryBufferRef Object) {
276  sys::fs::file_magic Type = sys::fs::identify_magic(Object.getBuffer());
277  switch (Type) {
278  case sys::fs::file_magic::bitcode:
279    return Object;
280  case sys::fs::file_magic::elf_relocatable:
281  case sys::fs::file_magic::macho_object:
282  case sys::fs::file_magic::coff_object: {
283    ErrorOr<std::unique_ptr<ObjectFile>> ObjFile =
284        ObjectFile::createObjectFile(Object, Type);
285    if (!ObjFile)
286      return ObjFile.getError();
287    return findBitcodeInObject(*ObjFile->get());
288  }
289  default:
290    return object_error::invalid_file_type;
291  }
292}
293
294ErrorOr<std::unique_ptr<IRObjectFile>>
295llvm::object::IRObjectFile::create(MemoryBufferRef Object,
296                                   LLVMContext &Context) {
297  ErrorOr<MemoryBufferRef> BCOrErr = findBitcodeInMemBuffer(Object);
298  if (!BCOrErr)
299    return BCOrErr.getError();
300
301  std::unique_ptr<MemoryBuffer> Buff(
302      MemoryBuffer::getMemBuffer(BCOrErr.get(), false));
303
304  ErrorOr<Module *> MOrErr = getLazyBitcodeModule(std::move(Buff), Context);
305  if (std::error_code EC = MOrErr.getError())
306    return EC;
307
308  std::unique_ptr<Module> M(MOrErr.get());
309  return llvm::make_unique<IRObjectFile>(Object, std::move(M));
310}
311