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
22 using namespace llvm;
23 using namespace object;
24
25 static Error
malformedError(Twine Msg)26 malformedError(Twine Msg) {
27 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
28 return make_error<GenericBinaryError>(std::move(StringMsg),
29 object_error::parse_failed);
30 }
31
32 template<typename T>
getUniversalBinaryStruct(const char * Ptr)33 static T getUniversalBinaryStruct(const char *Ptr) {
34 T Res;
35 memcpy(&Res, Ptr, sizeof(T));
36 // Universal binary headers have big-endian byte order.
37 if (sys::IsLittleEndianHost)
38 swapStruct(Res);
39 return Res;
40 }
41
ObjectForArch(const MachOUniversalBinary * Parent,uint32_t Index)42 MachOUniversalBinary::ObjectForArch::ObjectForArch(
43 const MachOUniversalBinary *Parent, uint32_t Index)
44 : Parent(Parent), Index(Index) {
45 if (!Parent || Index >= Parent->getNumberOfObjects()) {
46 clear();
47 } else {
48 // Parse object header.
49 StringRef ParentData = Parent->getData();
50 if (Parent->getMagic() == MachO::FAT_MAGIC) {
51 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
52 Index * sizeof(MachO::fat_arch);
53 Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
54 if (ParentData.size() < Header.offset + Header.size) {
55 clear();
56 }
57 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
58 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
59 Index * sizeof(MachO::fat_arch_64);
60 Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
61 if (ParentData.size() < Header64.offset + Header64.size) {
62 clear();
63 }
64 }
65 }
66 }
67
68 Expected<std::unique_ptr<MachOObjectFile>>
getAsObjectFile() const69 MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
70 if (!Parent)
71 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
72 "called when Parent is a nullptr");
73
74 StringRef ParentData = Parent->getData();
75 StringRef ObjectData;
76 if (Parent->getMagic() == MachO::FAT_MAGIC)
77 ObjectData = ParentData.substr(Header.offset, Header.size);
78 else // Parent->getMagic() == MachO::FAT_MAGIC_64
79 ObjectData = ParentData.substr(Header64.offset, Header64.size);
80 StringRef ObjectName = Parent->getFileName();
81 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
82 return ObjectFile::createMachOObjectFile(ObjBuffer);
83 }
84
85 Expected<std::unique_ptr<Archive>>
getAsArchive() const86 MachOUniversalBinary::ObjectForArch::getAsArchive() const {
87 if (!Parent)
88 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
89 "called when Parent is a nullptr");
90
91 StringRef ParentData = Parent->getData();
92 StringRef ObjectData;
93 if (Parent->getMagic() == MachO::FAT_MAGIC)
94 ObjectData = ParentData.substr(Header.offset, Header.size);
95 else // Parent->getMagic() == MachO::FAT_MAGIC_64
96 ObjectData = ParentData.substr(Header64.offset, Header64.size);
97 StringRef ObjectName = Parent->getFileName();
98 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
99 return Archive::create(ObjBuffer);
100 }
101
anchor()102 void MachOUniversalBinary::anchor() { }
103
104 Expected<std::unique_ptr<MachOUniversalBinary>>
create(MemoryBufferRef Source)105 MachOUniversalBinary::create(MemoryBufferRef Source) {
106 Error Err;
107 std::unique_ptr<MachOUniversalBinary> Ret(
108 new MachOUniversalBinary(Source, Err));
109 if (Err)
110 return std::move(Err);
111 return std::move(Ret);
112 }
113
MachOUniversalBinary(MemoryBufferRef Source,Error & Err)114 MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
115 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
116 NumberOfObjects(0) {
117 ErrorAsOutParameter ErrAsOutParam(Err);
118 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
119 Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
120 "universal file",
121 object_error::invalid_file_type);
122 return;
123 }
124 // Check for magic value and sufficient header size.
125 StringRef Buf = getData();
126 MachO::fat_header H =
127 getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
128 Magic = H.magic;
129 NumberOfObjects = H.nfat_arch;
130 uint32_t MinSize = sizeof(MachO::fat_header);
131 if (Magic == MachO::FAT_MAGIC)
132 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
133 else if (Magic == MachO::FAT_MAGIC_64)
134 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
135 else {
136 Err = malformedError("bad magic number");
137 return;
138 }
139 if (Buf.size() < MinSize) {
140 Err = malformedError("fat_arch" +
141 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
142 " structs would extend past the end of the file");
143 return;
144 }
145 Err = Error::success();
146 }
147
148 Expected<std::unique_ptr<MachOObjectFile>>
getObjectForArch(StringRef ArchName) const149 MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
150 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
151 return make_error<GenericBinaryError>("Unknown architecture "
152 "named: " +
153 ArchName,
154 object_error::arch_not_found);
155
156 for (object_iterator I = begin_objects(), E = end_objects(); I != E; ++I) {
157 if (I->getArchTypeName() == ArchName)
158 return I->getAsObjectFile();
159 }
160 return make_error<GenericBinaryError>("fat file does not "
161 "contain " +
162 ArchName,
163 object_error::arch_not_found);
164 }
165