1 //===- MachOUniversal.cpp - Mach-O universal binary -------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the MachOUniversalBinary class.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Object/MachOUniversal.h"
14 #include "llvm/Object/Archive.h"
15 #include "llvm/Object/MachO.h"
16 #include "llvm/Object/ObjectFile.h"
17 #include "llvm/Support/Casting.h"
18 #include "llvm/Support/Host.h"
19 #include "llvm/Support/MemoryBuffer.h"
20
21 using namespace llvm;
22 using namespace object;
23
24 static Error
malformedError(Twine Msg)25 malformedError(Twine Msg) {
26 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
27 return make_error<GenericBinaryError>(std::move(StringMsg),
28 object_error::parse_failed);
29 }
30
31 template<typename T>
getUniversalBinaryStruct(const char * Ptr)32 static T getUniversalBinaryStruct(const char *Ptr) {
33 T Res;
34 memcpy(&Res, Ptr, sizeof(T));
35 // Universal binary headers have big-endian byte order.
36 if (sys::IsLittleEndianHost)
37 swapStruct(Res);
38 return Res;
39 }
40
ObjectForArch(const MachOUniversalBinary * Parent,uint32_t Index)41 MachOUniversalBinary::ObjectForArch::ObjectForArch(
42 const MachOUniversalBinary *Parent, uint32_t Index)
43 : Parent(Parent), Index(Index) {
44 // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
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 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
55 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
56 Index * sizeof(MachO::fat_arch_64);
57 Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
58 }
59 }
60 }
61
62 Expected<std::unique_ptr<MachOObjectFile>>
getAsObjectFile() const63 MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
64 if (!Parent)
65 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
66 "called when Parent is a nullptr");
67
68 StringRef ParentData = Parent->getData();
69 StringRef ObjectData;
70 uint32_t cputype;
71 if (Parent->getMagic() == MachO::FAT_MAGIC) {
72 ObjectData = ParentData.substr(Header.offset, Header.size);
73 cputype = Header.cputype;
74 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
75 ObjectData = ParentData.substr(Header64.offset, Header64.size);
76 cputype = Header64.cputype;
77 }
78 StringRef ObjectName = Parent->getFileName();
79 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
80 return ObjectFile::createMachOObjectFile(ObjBuffer, cputype, Index);
81 }
82
83 Expected<std::unique_ptr<Archive>>
getAsArchive() const84 MachOUniversalBinary::ObjectForArch::getAsArchive() const {
85 if (!Parent)
86 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
87 "called when Parent is a nullptr");
88
89 StringRef ParentData = Parent->getData();
90 StringRef ObjectData;
91 if (Parent->getMagic() == MachO::FAT_MAGIC)
92 ObjectData = ParentData.substr(Header.offset, Header.size);
93 else // Parent->getMagic() == MachO::FAT_MAGIC_64
94 ObjectData = ParentData.substr(Header64.offset, Header64.size);
95 StringRef ObjectName = Parent->getFileName();
96 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
97 return Archive::create(ObjBuffer);
98 }
99
anchor()100 void MachOUniversalBinary::anchor() { }
101
102 Expected<std::unique_ptr<MachOUniversalBinary>>
create(MemoryBufferRef Source)103 MachOUniversalBinary::create(MemoryBufferRef Source) {
104 Error Err = Error::success();
105 std::unique_ptr<MachOUniversalBinary> Ret(
106 new MachOUniversalBinary(Source, Err));
107 if (Err)
108 return std::move(Err);
109 return std::move(Ret);
110 }
111
MachOUniversalBinary(MemoryBufferRef Source,Error & Err)112 MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
113 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
114 NumberOfObjects(0) {
115 ErrorAsOutParameter ErrAsOutParam(&Err);
116 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
117 Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
118 "universal file",
119 object_error::invalid_file_type);
120 return;
121 }
122 // Check for magic value and sufficient header size.
123 StringRef Buf = getData();
124 MachO::fat_header H =
125 getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
126 Magic = H.magic;
127 NumberOfObjects = H.nfat_arch;
128 if (NumberOfObjects == 0) {
129 Err = malformedError("contains zero architecture types");
130 return;
131 }
132 uint32_t MinSize = sizeof(MachO::fat_header);
133 if (Magic == MachO::FAT_MAGIC)
134 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
135 else if (Magic == MachO::FAT_MAGIC_64)
136 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
137 else {
138 Err = malformedError("bad magic number");
139 return;
140 }
141 if (Buf.size() < MinSize) {
142 Err = malformedError("fat_arch" +
143 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
144 " structs would extend past the end of the file");
145 return;
146 }
147 for (uint32_t i = 0; i < NumberOfObjects; i++) {
148 ObjectForArch A(this, i);
149 uint64_t bigSize = A.getOffset();
150 bigSize += A.getSize();
151 if (bigSize > Buf.size()) {
152 Err = malformedError("offset plus size of cputype (" +
153 Twine(A.getCPUType()) + ") cpusubtype (" +
154 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
155 ") extends past the end of the file");
156 return;
157 }
158
159 if (A.getAlign() > MaxSectionAlignment) {
160 Err = malformedError("align (2^" + Twine(A.getAlign()) +
161 ") too large for cputype (" + Twine(A.getCPUType()) +
162 ") cpusubtype (" +
163 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
164 ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
165 return;
166 }
167 if(A.getOffset() % (1ull << A.getAlign()) != 0){
168 Err = malformedError("offset: " + Twine(A.getOffset()) +
169 " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
170 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
171 ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
172 return;
173 }
174 if (A.getOffset() < MinSize) {
175 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
176 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
177 ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
178 return;
179 }
180 }
181 for (uint32_t i = 0; i < NumberOfObjects; i++) {
182 ObjectForArch A(this, i);
183 for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
184 ObjectForArch B(this, j);
185 if (A.getCPUType() == B.getCPUType() &&
186 (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
187 (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
188 Err = malformedError("contains two of the same architecture (cputype "
189 "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
190 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
191 return;
192 }
193 if ((A.getOffset() >= B.getOffset() &&
194 A.getOffset() < B.getOffset() + B.getSize()) ||
195 (A.getOffset() + A.getSize() > B.getOffset() &&
196 A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
197 (A.getOffset() <= B.getOffset() &&
198 A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
199 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
200 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
201 ") at offset " + Twine(A.getOffset()) + " with a size of " +
202 Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
203 ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
204 + ") at offset " + Twine(B.getOffset()) + " with a size of "
205 + Twine(B.getSize()));
206 return;
207 }
208 }
209 }
210 Err = Error::success();
211 }
212
213 Expected<MachOUniversalBinary::ObjectForArch>
getObjectForArch(StringRef ArchName) const214 MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
215 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
216 return make_error<GenericBinaryError>("Unknown architecture "
217 "named: " +
218 ArchName,
219 object_error::arch_not_found);
220 for (const auto &Obj : objects())
221 if (Obj.getArchFlagName() == ArchName)
222 return Obj;
223 return make_error<GenericBinaryError>("fat file does not "
224 "contain " +
225 ArchName,
226 object_error::arch_not_found);
227 }
228
229 Expected<std::unique_ptr<MachOObjectFile>>
getMachOObjectForArch(StringRef ArchName) const230 MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
231 Expected<ObjectForArch> O = getObjectForArch(ArchName);
232 if (!O)
233 return O.takeError();
234 return O->getAsObjectFile();
235 }
236
237 Expected<std::unique_ptr<Archive>>
getArchiveForArch(StringRef ArchName) const238 MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
239 Expected<ObjectForArch> O = getObjectForArch(ArchName);
240 if (!O)
241 return O.takeError();
242 return O->getAsArchive();
243 }
244