IRObjectFile.cpp revision 296417 
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/ADT/STLExtras.h"
17#include "llvm/Bitcode/ReaderWriter.h"
18#include "llvm/IR/GVMaterializer.h"
19#include "llvm/IR/LLVMContext.h"
20#include "llvm/IR/Mangler.h"
21#include "llvm/IR/Module.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/MCParser/MCAsmParser.h"
27#include "llvm/MC/MCRegisterInfo.h"
28#include "llvm/MC/MCSubtargetInfo.h"
29#include "llvm/MC/MCTargetAsmParser.h"
30#include "llvm/Object/ObjectFile.h"
31#include "llvm/Support/MemoryBuffer.h"
32#include "llvm/Support/SourceMgr.h"
33#include "llvm/Support/TargetRegistry.h"
34#include "llvm/Support/raw_ostream.h"
35using namespace llvm;
36using namespace object;
37
38IRObjectFile::IRObjectFile(MemoryBufferRef Object, std::unique_ptr<Module> Mod)
39    : SymbolicFile(Binary::ID_IR, Object), M(std::move(Mod)) {
40  Mang.reset(new Mangler());
41
42  const std::string &InlineAsm = M->getModuleInlineAsm();
43  if (InlineAsm.empty())
44    return;
45
46  Triple TT(M->getTargetTriple());
47  std::string Err;
48  const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
49  if (!T)
50    return;
51
52  std::unique_ptr<MCRegisterInfo> MRI(T->createMCRegInfo(TT.str()));
53  if (!MRI)
54    return;
55
56  std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, TT.str()));
57  if (!MAI)
58    return;
59
60  std::unique_ptr<MCSubtargetInfo> STI(
61      T->createMCSubtargetInfo(TT.str(), "", ""));
62  if (!STI)
63    return;
64
65  std::unique_ptr<MCInstrInfo> MCII(T->createMCInstrInfo());
66  if (!MCII)
67    return;
68
69  MCObjectFileInfo MOFI;
70  MCContext MCCtx(MAI.get(), MRI.get(), &MOFI);
71  MOFI.InitMCObjectFileInfo(TT, Reloc::Default, CodeModel::Default, MCCtx);
72  std::unique_ptr<RecordStreamer> Streamer(new RecordStreamer(MCCtx));
73  T->createNullTargetStreamer(*Streamer);
74
75  std::unique_ptr<MemoryBuffer> Buffer(MemoryBuffer::getMemBuffer(InlineAsm));
76  SourceMgr SrcMgr;
77  SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
78  std::unique_ptr<MCAsmParser> Parser(
79      createMCAsmParser(SrcMgr, MCCtx, *Streamer, *MAI));
80
81  MCTargetOptions MCOptions;
82  std::unique_ptr<MCTargetAsmParser> TAP(
83      T->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
84  if (!TAP)
85    return;
86
87  Parser->setTargetParser(*TAP);
88  if (Parser->Run(false))
89    return;
90
91  for (auto &KV : *Streamer) {
92    StringRef Key = KV.first();
93    RecordStreamer::State Value = KV.second;
94    uint32_t Res = BasicSymbolRef::SF_None;
95    switch (Value) {
96    case RecordStreamer::NeverSeen:
97      llvm_unreachable("foo");
98    case RecordStreamer::DefinedGlobal:
99      Res |= BasicSymbolRef::SF_Global;
100      break;
101    case RecordStreamer::Defined:
102      break;
103    case RecordStreamer::Global:
104    case RecordStreamer::Used:
105      Res |= BasicSymbolRef::SF_Undefined;
106      Res |= BasicSymbolRef::SF_Global;
107      break;
108    }
109    AsmSymbols.push_back(
110        std::make_pair<std::string, uint32_t>(Key, std::move(Res)));
111  }
112}
113
114IRObjectFile::~IRObjectFile() {
115 }
116
117static GlobalValue *getGV(DataRefImpl &Symb) {
118  if ((Symb.p & 3) == 3)
119    return nullptr;
120
121  return reinterpret_cast<GlobalValue*>(Symb.p & ~uintptr_t(3));
122}
123
124static uintptr_t skipEmpty(Module::const_alias_iterator I, const Module &M) {
125  if (I == M.alias_end())
126    return 3;
127  const GlobalValue *GV = &*I;
128  return reinterpret_cast<uintptr_t>(GV) | 2;
129}
130
131static uintptr_t skipEmpty(Module::const_global_iterator I, const Module &M) {
132  if (I == M.global_end())
133    return skipEmpty(M.alias_begin(), M);
134  const GlobalValue *GV = &*I;
135  return reinterpret_cast<uintptr_t>(GV) | 1;
136}
137
138static uintptr_t skipEmpty(Module::const_iterator I, const Module &M) {
139  if (I == M.end())
140    return skipEmpty(M.global_begin(), M);
141  const GlobalValue *GV = &*I;
142  return reinterpret_cast<uintptr_t>(GV) | 0;
143}
144
145static unsigned getAsmSymIndex(DataRefImpl Symb) {
146  assert((Symb.p & uintptr_t(3)) == 3);
147  uintptr_t Index = Symb.p & ~uintptr_t(3);
148  Index >>= 2;
149  return Index;
150}
151
152void IRObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
153  const GlobalValue *GV = getGV(Symb);
154  uintptr_t Res;
155
156  switch (Symb.p & 3) {
157  case 0: {
158    Module::const_iterator Iter(static_cast<const Function*>(GV));
159    ++Iter;
160    Res = skipEmpty(Iter, *M);
161    break;
162  }
163  case 1: {
164    Module::const_global_iterator Iter(static_cast<const GlobalVariable*>(GV));
165    ++Iter;
166    Res = skipEmpty(Iter, *M);
167    break;
168  }
169  case 2: {
170    Module::const_alias_iterator Iter(static_cast<const GlobalAlias*>(GV));
171    ++Iter;
172    Res = skipEmpty(Iter, *M);
173    break;
174  }
175  case 3: {
176    unsigned Index = getAsmSymIndex(Symb);
177    assert(Index < AsmSymbols.size());
178    ++Index;
179    Res = (Index << 2) | 3;
180    break;
181  }
182  default:
183    llvm_unreachable("unreachable case");
184  }
185
186  Symb.p = Res;
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());
195    OS << AsmSymbols[Index].first;
196    return std::error_code();
197  }
198
199  if (GV->hasDLLImportStorageClass())
200    OS << "__imp_";
201
202  if (Mang)
203    Mang->getNameWithPrefix(OS, GV, false);
204  else
205    OS << GV->getName();
206
207  return std::error_code();
208}
209
210uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
211  const GlobalValue *GV = getGV(Symb);
212
213  if (!GV) {
214    unsigned Index = getAsmSymIndex(Symb);
215    assert(Index <= AsmSymbols.size());
216    return AsmSymbols[Index].second;
217  }
218
219  uint32_t Res = BasicSymbolRef::SF_None;
220  if (GV->isDeclarationForLinker())
221    Res |= BasicSymbolRef::SF_Undefined;
222  else if (GV->hasHiddenVisibility() && !GV->hasLocalLinkage())
223    Res |= BasicSymbolRef::SF_Hidden;
224  if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
225    if (GVar->isConstant())
226      Res |= BasicSymbolRef::SF_Const;
227  }
228  if (GV->hasPrivateLinkage())
229    Res |= BasicSymbolRef::SF_FormatSpecific;
230  if (!GV->hasLocalLinkage())
231    Res |= BasicSymbolRef::SF_Global;
232  if (GV->hasCommonLinkage())
233    Res |= BasicSymbolRef::SF_Common;
234  if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage())
235    Res |= BasicSymbolRef::SF_Weak;
236
237  if (GV->getName().startswith("llvm."))
238    Res |= BasicSymbolRef::SF_FormatSpecific;
239  else if (auto *Var = dyn_cast<GlobalVariable>(GV)) {
240    if (Var->getSection() == StringRef("llvm.metadata"))
241      Res |= BasicSymbolRef::SF_FormatSpecific;
242  }
243
244  return Res;
245}
246
247GlobalValue *IRObjectFile::getSymbolGV(DataRefImpl Symb) { return getGV(Symb); }
248
249std::unique_ptr<Module> IRObjectFile::takeModule() { return std::move(M); }
250
251basic_symbol_iterator IRObjectFile::symbol_begin_impl() const {
252  Module::const_iterator I = M->begin();
253  DataRefImpl Ret;
254  Ret.p = skipEmpty(I, *M);
255  return basic_symbol_iterator(BasicSymbolRef(Ret, this));
256}
257
258basic_symbol_iterator IRObjectFile::symbol_end_impl() const {
259  DataRefImpl Ret;
260  uint64_t NumAsm = AsmSymbols.size();
261  NumAsm <<= 2;
262  Ret.p = 3 | NumAsm;
263  return basic_symbol_iterator(BasicSymbolRef(Ret, this));
264}
265
266ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInObject(const ObjectFile &Obj) {
267  for (const SectionRef &Sec : Obj.sections()) {
268    StringRef SecName;
269    if (std::error_code EC = Sec.getName(SecName))
270      return EC;
271    if (SecName == ".llvmbc") {
272      StringRef SecContents;
273      if (std::error_code EC = Sec.getContents(SecContents))
274        return EC;
275      return MemoryBufferRef(SecContents, Obj.getFileName());
276    }
277  }
278
279  return object_error::bitcode_section_not_found;
280}
281
282ErrorOr<MemoryBufferRef> IRObjectFile::findBitcodeInMemBuffer(MemoryBufferRef Object) {
283  sys::fs::file_magic Type = sys::fs::identify_magic(Object.getBuffer());
284  switch (Type) {
285  case sys::fs::file_magic::bitcode:
286    return Object;
287  case sys::fs::file_magic::elf_relocatable:
288  case sys::fs::file_magic::macho_object:
289  case sys::fs::file_magic::coff_object: {
290    ErrorOr<std::unique_ptr<ObjectFile>> ObjFile =
291        ObjectFile::createObjectFile(Object, Type);
292    if (!ObjFile)
293      return ObjFile.getError();
294    return findBitcodeInObject(*ObjFile->get());
295  }
296  default:
297    return object_error::invalid_file_type;
298  }
299}
300
301ErrorOr<std::unique_ptr<IRObjectFile>>
302llvm::object::IRObjectFile::create(MemoryBufferRef Object,
303                                   LLVMContext &Context) {
304  ErrorOr<MemoryBufferRef> BCOrErr = findBitcodeInMemBuffer(Object);
305  if (!BCOrErr)
306    return BCOrErr.getError();
307
308  std::unique_ptr<MemoryBuffer> Buff(
309      MemoryBuffer::getMemBuffer(BCOrErr.get(), false));
310
311  ErrorOr<std::unique_ptr<Module>> MOrErr =
312      getLazyBitcodeModule(std::move(Buff), Context,
313                           /*ShouldLazyLoadMetadata*/ true);
314  if (std::error_code EC = MOrErr.getError())
315    return EC;
316
317  std::unique_ptr<Module> &M = MOrErr.get();
318  return llvm::make_unique<IRObjectFile>(Object, std::move(M));
319}
320