lib/Object/MachOObjectFile.cpp

   1 //===- MachOObjectFile.cpp - Mach-O object file binding ---------*- 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 // This file defines the MachOObjectFile class, which binds the MachOObject
  11 // class to the generic ObjectFile wrapper.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Object/MachO.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/Object/MachOFormat.h"
  18 #include "llvm/Support/Casting.h"
  19 #include "llvm/Support/DataExtractor.h"
  20 #include "llvm/Support/Format.h"
  21 #include "llvm/Support/MemoryBuffer.h"
  22 #include <cctype>
  23 #include <cstring>
  24 #include <limits>
  25
  26 using namespace llvm;
  27 using namespace object;
  28
  29 namespace llvm {
  30 namespace object {
  31
  32 MachOObjectFileBase::MachOObjectFileBase(MemoryBuffer *Object,
  33                                          bool IsLittleEndian, bool Is64bits,
  34                                          error_code &ec)
  35     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object) {
  36 }
  37
  38 bool MachOObjectFileBase::is64Bit() const {
  39   return isa<MachOObjectFileLE64>(this) || isa<MachOObjectFileBE64>(this);
  40 }
  41
  42 void MachOObjectFileBase::ReadULEB128s(uint64_t Index,
  43                                        SmallVectorImpl<uint64_t> &Out) const {
  44   DataExtractor extractor(ObjectFile::getData(), true, 0);
  45
  46   uint32_t offset = Index;
  47   uint64_t data = 0;
  48   while (uint64_t delta = extractor.getULEB128(&offset)) {
  49     data += delta;
  50     Out.push_back(data);
  51   }
  52 }
  53
  54 unsigned MachOObjectFileBase::getHeaderSize() const {
  55   return is64Bit() ? macho::Header64Size : macho::Header32Size;
  56 }
  57
  58 StringRef MachOObjectFileBase::getData(size_t Offset, size_t Size) const {
  59   return ObjectFile::getData().substr(Offset, Size);
  60 }
  61
  62 ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
  63   StringRef Magic = Buffer->getBuffer().slice(0, 4);
  64   error_code ec;
  65   ObjectFile *Ret;
  66   if (Magic == "\xFE\xED\xFA\xCE")
  67     Ret = new MachOObjectFileBE32(Buffer, ec);
  68   else if (Magic == "\xCE\xFA\xED\xFE")
  69     Ret = new MachOObjectFileLE32(Buffer, ec);
  70   else if (Magic == "\xFE\xED\xFA\xCF")
  71     Ret = new MachOObjectFileBE64(Buffer, ec);
  72   else if (Magic == "\xCF\xFA\xED\xFE")
  73     Ret = new MachOObjectFileLE64(Buffer, ec);
  74   else
  75     return NULL;
  76
  77   if (ec)
  78     return NULL;
  79   return Ret;
  80 }
  81
  82 /*===-- Symbols -----------------------------------------------------------===*/
  83
  84 error_code MachOObjectFileBase::getSymbolValue(DataRefImpl Symb,
  85                                                uint64_t &Val) const {
  86   report_fatal_error("getSymbolValue unimplemented in MachOObjectFileBase");
  87 }
  88
  89 symbol_iterator MachOObjectFileBase::begin_dynamic_symbols() const {
  90   // TODO: implement
  91   report_fatal_error("Dynamic symbols unimplemented in MachOObjectFileBase");
  92 }
  93
  94 symbol_iterator MachOObjectFileBase::end_dynamic_symbols() const {
  95   // TODO: implement
  96   report_fatal_error("Dynamic symbols unimplemented in MachOObjectFileBase");
  97 }
  98
  99 library_iterator MachOObjectFileBase::begin_libraries_needed() const {
 100   // TODO: implement
 101   report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
 102 }
 103
 104 library_iterator MachOObjectFileBase::end_libraries_needed() const {
 105   // TODO: implement
 106   report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
 107 }
 108
 109 StringRef MachOObjectFileBase::getLoadName() const {
 110   // TODO: Implement
 111   report_fatal_error("get_load_name() unimplemented in MachOObjectFileBase");
 112 }
 113
 114 /*===-- Sections ----------------------------------------------------------===*/
 115
 116 std::size_t MachOObjectFileBase::getSectionIndex(DataRefImpl Sec) const {
 117   SectionList::const_iterator loc =
 118     std::find(Sections.begin(), Sections.end(), Sec);
 119   assert(loc != Sections.end() && "Sec is not a valid section!");
 120   return std::distance(Sections.begin(), loc);
 121 }
 122
 123 StringRef MachOObjectFileBase::parseSegmentOrSectionName(const char *P) const {
 124   if (P[15] == 0)
 125     // Null terminated.
 126     return P;
 127   // Not null terminated, so this is a 16 char string.
 128   return StringRef(P, 16);
 129 }
 130
 131 error_code MachOObjectFileBase::isSectionData(DataRefImpl DRI,
 132                                               bool &Result) const {
 133   // FIXME: Unimplemented.
 134   Result = false;
 135   return object_error::success;
 136 }
 137
 138 error_code MachOObjectFileBase::isSectionBSS(DataRefImpl DRI,
 139                                              bool &Result) const {
 140   // FIXME: Unimplemented.
 141   Result = false;
 142   return object_error::success;
 143 }
 144
 145 error_code
 146 MachOObjectFileBase::isSectionRequiredForExecution(DataRefImpl Sec,
 147                                                    bool &Result) const {
 148   // FIXME: Unimplemented.
 149   Result = true;
 150   return object_error::success;
 151 }
 152
 153 error_code MachOObjectFileBase::isSectionVirtual(DataRefImpl Sec,
 154                                                  bool &Result) const {
 155   // FIXME: Unimplemented.
 156   Result = false;
 157   return object_error::success;
 158 }
 159
 160 error_code MachOObjectFileBase::isSectionReadOnlyData(DataRefImpl Sec,
 161                                                       bool &Result) const {
 162   // Consider using the code from isSectionText to look for __const sections.
 163   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
 164   // to use section attributes to distinguish code from data.
 165
 166   // FIXME: Unimplemented.
 167   Result = false;
 168   return object_error::success;
 169 }
 170
 171 relocation_iterator MachOObjectFileBase::getSectionRelBegin(DataRefImpl Sec) const {
 172   DataRefImpl ret;
 173   ret.d.b = getSectionIndex(Sec);
 174   return relocation_iterator(RelocationRef(ret, this));
 175 }
 176
 177
 178 /*===-- Relocations -------------------------------------------------------===*/
 179
 180 error_code MachOObjectFileBase::getRelocationNext(DataRefImpl Rel,
 181                                                   RelocationRef &Res) const {
 182   ++Rel.d.a;
 183   Res = RelocationRef(Rel, this);
 184   return object_error::success;
 185 }
 186
 187 error_code MachOObjectFileBase::getLibraryNext(DataRefImpl LibData,
 188                                                LibraryRef &Res) const {
 189   report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
 190 }
 191
 192 error_code MachOObjectFileBase::getLibraryPath(DataRefImpl LibData,
 193                                                StringRef &Res) const {
 194   report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
 195 }
 196
 197 error_code MachOObjectFileBase::getRelocationAdditionalInfo(DataRefImpl Rel,
 198                                                            int64_t &Res) const {
 199   Res = 0;
 200   return object_error::success;
 201 }
 202
 203
 204 /*===-- Miscellaneous -----------------------------------------------------===*/
 205
 206 uint8_t MachOObjectFileBase::getBytesInAddress() const {
 207   return is64Bit() ? 8 : 4;
 208 }
 209
 210 } // end namespace object
 211 } // end namespace llvm