reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    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
//===- ObjectFile.cpp - File format independent object file ---------------===//
//
// 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 file defines a file format independent ObjectFile class.
//
//===----------------------------------------------------------------------===//

#include "llvm/Object/ObjectFile.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/COFF.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/Wasm.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdint>
#include <memory>
#include <system_error>

using namespace llvm;
using namespace object;

void ObjectFile::anchor() {}

ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
    : SymbolicFile(Type, Source) {}

bool SectionRef::containsSymbol(SymbolRef S) const {
  Expected<section_iterator> SymSec = S.getSection();
  if (!SymSec) {
    // TODO: Actually report errors helpfully.
    consumeError(SymSec.takeError());
    return false;
  }
  return *this == **SymSec;
}

uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const {
  uint32_t Flags = getSymbolFlags(Ref);
  if (Flags & SymbolRef::SF_Undefined)
    return 0;
  if (Flags & SymbolRef::SF_Common)
    return getCommonSymbolSize(Ref);
  return getSymbolValueImpl(Ref);
}

Error ObjectFile::printSymbolName(raw_ostream &OS, DataRefImpl Symb) const {
  Expected<StringRef> Name = getSymbolName(Symb);
  if (!Name)
    return Name.takeError();
  OS << *Name;
  return Error::success();
}

uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }

bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
  Expected<StringRef> NameOrErr = getSectionName(Sec);
  if (NameOrErr)
    return *NameOrErr == ".llvmbc";
  consumeError(NameOrErr.takeError());
  return false;
}

bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; }

bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const {
  return isSectionText(Sec);
}

bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const {
  return isSectionData(Sec);
}

Expected<section_iterator>
ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
  return section_iterator(SectionRef(Sec, this));
}

Triple ObjectFile::makeTriple() const {
  Triple TheTriple;
  auto Arch = getArch();
  TheTriple.setArch(Triple::ArchType(Arch));

  // For ARM targets, try to use the build attributes to build determine
  // the build target. Target features are also added, but later during
  // disassembly.
  if (Arch == Triple::arm || Arch == Triple::armeb)
    setARMSubArch(TheTriple);

  // TheTriple defaults to ELF, and COFF doesn't have an environment:
  // the best we can do here is indicate that it is mach-o.
  if (isMachO())
    TheTriple.setObjectFormat(Triple::MachO);

  if (isCOFF()) {
    const auto COFFObj = cast<COFFObjectFile>(this);
    if (COFFObj->getArch() == Triple::thumb)
      TheTriple.setTriple("thumbv7-windows");
  }

  return TheTriple;
}

Expected<std::unique_ptr<ObjectFile>>
ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) {
  StringRef Data = Object.getBuffer();
  if (Type == file_magic::unknown)
    Type = identify_magic(Data);

  switch (Type) {
  case file_magic::unknown:
  case file_magic::bitcode:
  case file_magic::coff_cl_gl_object:
  case file_magic::archive:
  case file_magic::macho_universal_binary:
  case file_magic::windows_resource:
  case file_magic::pdb:
  case file_magic::minidump:
    return errorCodeToError(object_error::invalid_file_type);
  case file_magic::tapi_file:
    return errorCodeToError(object_error::invalid_file_type);
  case file_magic::elf:
  case file_magic::elf_relocatable:
  case file_magic::elf_executable:
  case file_magic::elf_shared_object:
  case file_magic::elf_core:
    return createELFObjectFile(Object);
  case file_magic::macho_object:
  case file_magic::macho_executable:
  case file_magic::macho_fixed_virtual_memory_shared_lib:
  case file_magic::macho_core:
  case file_magic::macho_preload_executable:
  case file_magic::macho_dynamically_linked_shared_lib:
  case file_magic::macho_dynamic_linker:
  case file_magic::macho_bundle:
  case file_magic::macho_dynamically_linked_shared_lib_stub:
  case file_magic::macho_dsym_companion:
  case file_magic::macho_kext_bundle:
    return createMachOObjectFile(Object);
  case file_magic::coff_object:
  case file_magic::coff_import_library:
  case file_magic::pecoff_executable:
    return createCOFFObjectFile(Object);
  case file_magic::xcoff_object_32:
    return createXCOFFObjectFile(Object, Binary::ID_XCOFF32);
  case file_magic::xcoff_object_64:
    return createXCOFFObjectFile(Object, Binary::ID_XCOFF64);
  case file_magic::wasm_object:
    return createWasmObjectFile(Object);
  }
  llvm_unreachable("Unexpected Object File Type");
}

Expected<OwningBinary<ObjectFile>>
ObjectFile::createObjectFile(StringRef ObjectPath) {
  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
      MemoryBuffer::getFile(ObjectPath);
  if (std::error_code EC = FileOrErr.getError())
    return errorCodeToError(EC);
  std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());

  Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
      createObjectFile(Buffer->getMemBufferRef());
  if (Error Err = ObjOrErr.takeError())
    return std::move(Err);
  std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());

  return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
}