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/Archive.h"
16#include "llvm/Object/MachO.h"
17#include "llvm/Object/ObjectFile.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<MachOObjectFile>>
71MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
72  if (!Parent)
73    return object_error::parse_failed;
74
75  StringRef ParentData = Parent->getData();
76  StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
77  StringRef ObjectName = Parent->getFileName();
78  MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
79  return ObjectFile::createMachOObjectFile(ObjBuffer);
80}
81
82ErrorOr<std::unique_ptr<Archive>>
83MachOUniversalBinary::ObjectForArch::getAsArchive() const {
84  if (!Parent)
85    return object_error::parse_failed;
86
87  StringRef ParentData = Parent->getData();
88  StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
89  StringRef ObjectName = Parent->getFileName();
90  MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
91  return Archive::create(ObjBuffer);
92}
93
94void MachOUniversalBinary::anchor() { }
95
96ErrorOr<std::unique_ptr<MachOUniversalBinary>>
97MachOUniversalBinary::create(MemoryBufferRef Source) {
98  std::error_code EC;
99  std::unique_ptr<MachOUniversalBinary> Ret(
100      new MachOUniversalBinary(Source, EC));
101  if (EC)
102    return EC;
103  return std::move(Ret);
104}
105
106MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source,
107                                           std::error_code &ec)
108    : Binary(Binary::ID_MachOUniversalBinary, Source), NumberOfObjects(0) {
109  if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
110    ec = object_error::invalid_file_type;
111    return;
112  }
113  // Check for magic value and sufficient header size.
114  StringRef Buf = getData();
115  MachO::fat_header H= getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
116  NumberOfObjects = H.nfat_arch;
117  uint32_t MinSize = sizeof(MachO::fat_header) +
118                     sizeof(MachO::fat_arch) * NumberOfObjects;
119  if (H.magic != MachO::FAT_MAGIC || Buf.size() < MinSize) {
120    ec = object_error::parse_failed;
121    return;
122  }
123  ec = std::error_code();
124}
125
126ErrorOr<std::unique_ptr<MachOObjectFile>>
127MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
128  if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
129    return object_error::arch_not_found;
130
131  for (object_iterator I = begin_objects(), E = end_objects(); I != E; ++I) {
132    if (I->getArchTypeName() == ArchName)
133      return I->getAsObjectFile();
134  }
135  return object_error::arch_not_found;
136}
137