1//===- MachOUniversal.cpp - Mach-O universal binary -------------*- 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 MachOUniversalBinary class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Object/MachOUniversal.h"
15#include "llvm/Object/MachO.h"
16#include "llvm/Object/ObjectFile.h"
17#include "llvm/Object/Archive.h"
18#include "llvm/Support/Casting.h"
19#include "llvm/Support/Host.h"
20#include "llvm/Support/MemoryBuffer.h"
21
22using namespace llvm;
23using namespace object;
24
25template<typename T>
26static void SwapStruct(T &Value);
27
28template<>
29void SwapStruct(MachO::fat_header &H) {
30  sys::swapByteOrder(H.magic);
31  sys::swapByteOrder(H.nfat_arch);
32}
33
34template<>
35void SwapStruct(MachO::fat_arch &H) {
36  sys::swapByteOrder(H.cputype);
37  sys::swapByteOrder(H.cpusubtype);
38  sys::swapByteOrder(H.offset);
39  sys::swapByteOrder(H.size);
40  sys::swapByteOrder(H.align);
41}
42
43template<typename T>
44static T getUniversalBinaryStruct(const char *Ptr) {
45  T Res;
46  memcpy(&Res, Ptr, sizeof(T));
47  // Universal binary headers have big-endian byte order.
48  if (sys::IsLittleEndianHost)
49    SwapStruct(Res);
50  return Res;
51}
52
53MachOUniversalBinary::ObjectForArch::ObjectForArch(
54    const MachOUniversalBinary *Parent, uint32_t Index)
55    : Parent(Parent), Index(Index) {
56  if (!Parent || Index >= Parent->getNumberOfObjects()) {
57    clear();
58  } else {
59    // Parse object header.
60    StringRef ParentData = Parent->getData();
61    const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
62                            Index * sizeof(MachO::fat_arch);
63    Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
64    if (ParentData.size() < Header.offset + Header.size) {
65      clear();
66    }
67  }
68}
69
70ErrorOr<std::unique_ptr<ObjectFile>>
71MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
72  if (Parent) {
73    StringRef ParentData = Parent->getData();
74    StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
75    std::string ObjectName = Parent->getFileName().str();
76    std::unique_ptr<MemoryBuffer> ObjBuffer(
77        MemoryBuffer::getMemBuffer(ObjectData, ObjectName, false));
78    return ObjectFile::createMachOObjectFile(ObjBuffer);
79  }
80  return object_error::parse_failed;
81}
82
83std::error_code MachOUniversalBinary::ObjectForArch::getAsArchive(
84    std::unique_ptr<Archive> &Result) const {
85  if (Parent) {
86    StringRef ParentData = Parent->getData();
87    StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
88    std::string ObjectName = Parent->getFileName().str();
89    std::unique_ptr<MemoryBuffer> ObjBuffer(
90        MemoryBuffer::getMemBuffer(ObjectData, ObjectName, false));
91    ErrorOr<Archive *> Obj = Archive::create(std::move(ObjBuffer));
92    if (std::error_code EC = Obj.getError())
93      return EC;
94    Result.reset(Obj.get());
95    return object_error::success;
96  }
97  return object_error::parse_failed;
98}
99
100void MachOUniversalBinary::anchor() { }
101
102ErrorOr<MachOUniversalBinary *>
103MachOUniversalBinary::create(std::unique_ptr<MemoryBuffer> Source) {
104  std::error_code EC;
105  std::unique_ptr<MachOUniversalBinary> Ret(
106      new MachOUniversalBinary(std::move(Source), EC));
107  if (EC)
108    return EC;
109  return Ret.release();
110}
111
112MachOUniversalBinary::MachOUniversalBinary(std::unique_ptr<MemoryBuffer> Source,
113                                           std::error_code &ec)
114    : Binary(Binary::ID_MachOUniversalBinary, std::move(Source)),
115      NumberOfObjects(0) {
116  if (Data->getBufferSize() < sizeof(MachO::fat_header)) {
117    ec = object_error::invalid_file_type;
118    return;
119  }
120  // Check for magic value and sufficient header size.
121  StringRef Buf = getData();
122  MachO::fat_header H= getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
123  NumberOfObjects = H.nfat_arch;
124  uint32_t MinSize = sizeof(MachO::fat_header) +
125                     sizeof(MachO::fat_arch) * NumberOfObjects;
126  if (H.magic != MachO::FAT_MAGIC || Buf.size() < MinSize) {
127    ec = object_error::parse_failed;
128    return;
129  }
130  ec = object_error::success;
131}
132
133static bool getCTMForArch(Triple::ArchType Arch, MachO::CPUType &CTM) {
134  switch (Arch) {
135    case Triple::x86:    CTM = MachO::CPU_TYPE_I386; return true;
136    case Triple::x86_64: CTM = MachO::CPU_TYPE_X86_64; return true;
137    case Triple::arm:    CTM = MachO::CPU_TYPE_ARM; return true;
138    case Triple::sparc:  CTM = MachO::CPU_TYPE_SPARC; return true;
139    case Triple::ppc:    CTM = MachO::CPU_TYPE_POWERPC; return true;
140    case Triple::ppc64:  CTM = MachO::CPU_TYPE_POWERPC64; return true;
141    default: return false;
142  }
143}
144
145ErrorOr<std::unique_ptr<ObjectFile>>
146MachOUniversalBinary::getObjectForArch(Triple::ArchType Arch) const {
147  MachO::CPUType CTM;
148  if (!getCTMForArch(Arch, CTM))
149    return object_error::arch_not_found;
150  for (object_iterator I = begin_objects(), E = end_objects(); I != E; ++I) {
151    if (I->getCPUType() == static_cast<uint32_t>(CTM))
152      return I->getAsObjectFile();
153  }
154  return object_error::arch_not_found;
155}
156