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/IRObjectFile.h"
16#include "llvm/Object/MachO.h"
17#include "llvm/Object/ObjectFile.h"
18#include "llvm/Support/ErrorHandling.h"
19#include "llvm/Support/SwapByteOrder.h"
20#include "llvm/Support/type_traits.h"
21
22using namespace llvm;
23using namespace object;
24
25static Error
26malformedError(Twine Msg) {
27 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
28 return make_error<GenericBinaryError>(Args: std::move(StringMsg),
29 Args: object_error::parse_failed);
30}
31
32template<typename T>
33static 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
42MachOUniversalBinary::ObjectForArch::ObjectForArch(
43 const MachOUniversalBinary *Parent, uint32_t Index)
44 : Parent(Parent), Index(Index) {
45 // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
46 if (!Parent || Index >= Parent->getNumberOfObjects()) {
47 clear();
48 } else {
49 // Parse object header.
50 StringRef ParentData = Parent->getData();
51 if (Parent->getMagic() == MachO::FAT_MAGIC) {
52 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
53 Index * sizeof(MachO::fat_arch);
54 Header = getUniversalBinaryStruct<MachO::fat_arch>(Ptr: HeaderPos);
55 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
56 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
57 Index * sizeof(MachO::fat_arch_64);
58 Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(Ptr: HeaderPos);
59 }
60 }
61}
62
63Expected<std::unique_ptr<MachOObjectFile>>
64MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
65 if (!Parent)
66 report_fatal_error(reason: "MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
67 "called when Parent is a nullptr");
68
69 StringRef ParentData = Parent->getData();
70 StringRef ObjectData;
71 uint32_t cputype;
72 if (Parent->getMagic() == MachO::FAT_MAGIC) {
73 ObjectData = ParentData.substr(Start: Header.offset, N: Header.size);
74 cputype = Header.cputype;
75 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
76 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
77 cputype = Header64.cputype;
78 }
79 StringRef ObjectName = Parent->getFileName();
80 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
81 return ObjectFile::createMachOObjectFile(Object: ObjBuffer, UniversalCputype: cputype, UniversalIndex: Index);
82}
83
84Expected<std::unique_ptr<IRObjectFile>>
85MachOUniversalBinary::ObjectForArch::getAsIRObject(LLVMContext &Ctx) const {
86 if (!Parent)
87 report_fatal_error(reason: "MachOUniversalBinary::ObjectForArch::getAsIRObject() "
88 "called when Parent is a nullptr");
89
90 StringRef ParentData = Parent->getData();
91 StringRef ObjectData;
92 if (Parent->getMagic() == MachO::FAT_MAGIC) {
93 ObjectData = ParentData.substr(Start: Header.offset, N: Header.size);
94 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
95 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
96 }
97 StringRef ObjectName = Parent->getFileName();
98 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
99
100 return IRObjectFile::create(Object: ObjBuffer, Context&: Ctx);
101}
102
103Expected<std::unique_ptr<Archive>>
104MachOUniversalBinary::ObjectForArch::getAsArchive() const {
105 if (!Parent)
106 report_fatal_error(reason: "MachOUniversalBinary::ObjectForArch::getAsArchive() "
107 "called when Parent is a nullptr");
108
109 StringRef ParentData = Parent->getData();
110 StringRef ObjectData;
111 if (Parent->getMagic() == MachO::FAT_MAGIC)
112 ObjectData = ParentData.substr(Start: Header.offset, N: Header.size);
113 else // Parent->getMagic() == MachO::FAT_MAGIC_64
114 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
115 StringRef ObjectName = Parent->getFileName();
116 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
117 return Archive::create(Source: ObjBuffer);
118}
119
120void MachOUniversalBinary::anchor() { }
121
122Expected<std::unique_ptr<MachOUniversalBinary>>
123MachOUniversalBinary::create(MemoryBufferRef Source) {
124 Error Err = Error::success();
125 std::unique_ptr<MachOUniversalBinary> Ret(
126 new MachOUniversalBinary(Source, Err));
127 if (Err)
128 return std::move(Err);
129 return std::move(Ret);
130}
131
132MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
133 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
134 NumberOfObjects(0) {
135 ErrorAsOutParameter ErrAsOutParam(&Err);
136 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
137 Err = make_error<GenericBinaryError>(Args: "File too small to be a Mach-O "
138 "universal file",
139 Args: object_error::invalid_file_type);
140 return;
141 }
142 // Check for magic value and sufficient header size.
143 StringRef Buf = getData();
144 MachO::fat_header H =
145 getUniversalBinaryStruct<MachO::fat_header>(Ptr: Buf.begin());
146 Magic = H.magic;
147 NumberOfObjects = H.nfat_arch;
148 if (NumberOfObjects == 0) {
149 Err = malformedError(Msg: "contains zero architecture types");
150 return;
151 }
152 uint32_t MinSize = sizeof(MachO::fat_header);
153 if (Magic == MachO::FAT_MAGIC)
154 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
155 else if (Magic == MachO::FAT_MAGIC_64)
156 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
157 else {
158 Err = malformedError(Msg: "bad magic number");
159 return;
160 }
161 if (Buf.size() < MinSize) {
162 Err = malformedError(Msg: "fat_arch" +
163 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
164 " structs would extend past the end of the file");
165 return;
166 }
167 for (uint32_t i = 0; i < NumberOfObjects; i++) {
168 ObjectForArch A(this, i);
169 uint64_t bigSize = A.getOffset();
170 bigSize += A.getSize();
171 if (bigSize > Buf.size()) {
172 Err = malformedError(Msg: "offset plus size of cputype (" +
173 Twine(A.getCPUType()) + ") cpusubtype (" +
174 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
175 ") extends past the end of the file");
176 return;
177 }
178
179 if (A.getAlign() > MaxSectionAlignment) {
180 Err = malformedError(Msg: "align (2^" + Twine(A.getAlign()) +
181 ") too large for cputype (" + Twine(A.getCPUType()) +
182 ") cpusubtype (" +
183 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
184 ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
185 return;
186 }
187 if(A.getOffset() % (1ull << A.getAlign()) != 0){
188 Err = malformedError(Msg: "offset: " + Twine(A.getOffset()) +
189 " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
190 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
191 ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
192 return;
193 }
194 if (A.getOffset() < MinSize) {
195 Err = malformedError(Msg: "cputype (" + Twine(A.getCPUType()) + ") "
196 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
197 ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
198 return;
199 }
200 }
201 for (uint32_t i = 0; i < NumberOfObjects; i++) {
202 ObjectForArch A(this, i);
203 for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
204 ObjectForArch B(this, j);
205 if (A.getCPUType() == B.getCPUType() &&
206 (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
207 (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
208 Err = malformedError(Msg: "contains two of the same architecture (cputype "
209 "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
210 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
211 return;
212 }
213 if ((A.getOffset() >= B.getOffset() &&
214 A.getOffset() < B.getOffset() + B.getSize()) ||
215 (A.getOffset() + A.getSize() > B.getOffset() &&
216 A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
217 (A.getOffset() <= B.getOffset() &&
218 A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
219 Err = malformedError(Msg: "cputype (" + Twine(A.getCPUType()) + ") "
220 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
221 ") at offset " + Twine(A.getOffset()) + " with a size of " +
222 Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
223 ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
224 + ") at offset " + Twine(B.getOffset()) + " with a size of "
225 + Twine(B.getSize()));
226 return;
227 }
228 }
229 }
230 Err = Error::success();
231}
232
233Expected<MachOUniversalBinary::ObjectForArch>
234MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
235 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
236 return make_error<GenericBinaryError>(Args: "Unknown architecture "
237 "named: " +
238 ArchName,
239 Args: object_error::arch_not_found);
240 for (const auto &Obj : objects())
241 if (Obj.getArchFlagName() == ArchName)
242 return Obj;
243 return make_error<GenericBinaryError>(Args: "fat file does not "
244 "contain " +
245 ArchName,
246 Args: object_error::arch_not_found);
247}
248
249Expected<std::unique_ptr<MachOObjectFile>>
250MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
251 Expected<ObjectForArch> O = getObjectForArch(ArchName);
252 if (!O)
253 return O.takeError();
254 return O->getAsObjectFile();
255}
256
257Expected<std::unique_ptr<IRObjectFile>>
258MachOUniversalBinary::getIRObjectForArch(StringRef ArchName,
259 LLVMContext &Ctx) const {
260 Expected<ObjectForArch> O = getObjectForArch(ArchName);
261 if (!O)
262 return O.takeError();
263 return O->getAsIRObject(Ctx);
264}
265
266Expected<std::unique_ptr<Archive>>
267MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
268 Expected<ObjectForArch> O = getObjectForArch(ArchName);
269 if (!O)
270 return O.takeError();
271 return O->getAsArchive();
272}
273

source code of llvm/lib/Object/MachOUniversal.cpp