ObjectFile.cpp revision 321369 
1//===- ObjectFile.cpp - File format independent object file ---------------===//
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// This file defines a file format independent ObjectFile class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Object/ObjectFile.h"
15#include "llvm/ADT/StringRef.h"
16#include "llvm/BinaryFormat/Magic.h"
17#include "llvm/Object/Binary.h"
18#include "llvm/Object/COFF.h"
19#include "llvm/Object/Error.h"
20#include "llvm/Object/MachO.h"
21#include "llvm/Object/Wasm.h"
22#include "llvm/Support/Error.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/ErrorOr.h"
25#include "llvm/Support/FileSystem.h"
26#include "llvm/Support/MemoryBuffer.h"
27#include "llvm/Support/raw_ostream.h"
28#include <algorithm>
29#include <cstdint>
30#include <memory>
31#include <system_error>
32
33using namespace llvm;
34using namespace object;
35
36void ObjectFile::anchor() {}
37
38ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
39    : SymbolicFile(Type, Source) {}
40
41bool SectionRef::containsSymbol(SymbolRef S) const {
42  Expected<section_iterator> SymSec = S.getSection();
43  if (!SymSec) {
44    // TODO: Actually report errors helpfully.
45    consumeError(SymSec.takeError());
46    return false;
47  }
48  return *this == **SymSec;
49}
50
51uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const {
52  uint32_t Flags = getSymbolFlags(Ref);
53  if (Flags & SymbolRef::SF_Undefined)
54    return 0;
55  if (Flags & SymbolRef::SF_Common)
56    return getCommonSymbolSize(Ref);
57  return getSymbolValueImpl(Ref);
58}
59
60std::error_code ObjectFile::printSymbolName(raw_ostream &OS,
61                                            DataRefImpl Symb) const {
62  Expected<StringRef> Name = getSymbolName(Symb);
63  if (!Name)
64    return errorToErrorCode(Name.takeError());
65  OS << *Name;
66  return std::error_code();
67}
68
69uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
70
71bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
72  StringRef SectName;
73  if (!getSectionName(Sec, SectName))
74    return SectName == ".llvmbc";
75  return false;
76}
77
78section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
79  return section_iterator(SectionRef(Sec, this));
80}
81
82Expected<std::unique_ptr<ObjectFile>>
83ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) {
84  StringRef Data = Object.getBuffer();
85  if (Type == file_magic::unknown)
86    Type = identify_magic(Data);
87
88  switch (Type) {
89  case file_magic::unknown:
90  case file_magic::bitcode:
91  case file_magic::coff_cl_gl_object:
92  case file_magic::archive:
93  case file_magic::macho_universal_binary:
94  case file_magic::windows_resource:
95    return errorCodeToError(object_error::invalid_file_type);
96  case file_magic::elf:
97  case file_magic::elf_relocatable:
98  case file_magic::elf_executable:
99  case file_magic::elf_shared_object:
100  case file_magic::elf_core:
101    return errorOrToExpected(createELFObjectFile(Object));
102  case file_magic::macho_object:
103  case file_magic::macho_executable:
104  case file_magic::macho_fixed_virtual_memory_shared_lib:
105  case file_magic::macho_core:
106  case file_magic::macho_preload_executable:
107  case file_magic::macho_dynamically_linked_shared_lib:
108  case file_magic::macho_dynamic_linker:
109  case file_magic::macho_bundle:
110  case file_magic::macho_dynamically_linked_shared_lib_stub:
111  case file_magic::macho_dsym_companion:
112  case file_magic::macho_kext_bundle:
113    return createMachOObjectFile(Object);
114  case file_magic::coff_object:
115  case file_magic::coff_import_library:
116  case file_magic::pecoff_executable:
117    return errorOrToExpected(createCOFFObjectFile(Object));
118  case file_magic::wasm_object:
119    return createWasmObjectFile(Object);
120  }
121  llvm_unreachable("Unexpected Object File Type");
122}
123
124Expected<OwningBinary<ObjectFile>>
125ObjectFile::createObjectFile(StringRef ObjectPath) {
126  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
127      MemoryBuffer::getFile(ObjectPath);
128  if (std::error_code EC = FileOrErr.getError())
129    return errorCodeToError(EC);
130  std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
131
132  Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
133      createObjectFile(Buffer->getMemBufferRef());
134  if (Error Err = ObjOrErr.takeError())
135    return std::move(Err);
136  std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
137
138  return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
139}
140