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
21using namespace llvm;
22using namespace object;
23
24static Error
25malformedError(Twine Msg) {
26 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
27 return make_error<GenericBinaryError>(Args: std::move(StringMsg),
28 Args: object_error::parse_failed);
29}
30
31template<typename T>
32static 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
41MachOUniversalBinary::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>(Ptr: 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>(Ptr: HeaderPos);
58 }
59 }
60}
61
62Expected<std::unique_ptr<MachOObjectFile>>
63MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
64 if (!Parent)
65 report_fatal_error(reason: "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(Start: Header.offset, N: Header.size);
73 cputype = Header.cputype;
74 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
75 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
76 cputype = Header64.cputype;
77 }
78 StringRef ObjectName = Parent->getFileName();
79 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
80 return ObjectFile::createMachOObjectFile(Object: ObjBuffer, UniversalCputype: cputype, UniversalIndex: Index);
81}
82
83Expected<std::unique_ptr<IRObjectFile>>
84MachOUniversalBinary::ObjectForArch::getAsIRObject(LLVMContext &Ctx) const {
85 if (!Parent)
86 report_fatal_error(reason: "MachOUniversalBinary::ObjectForArch::getAsIRObject() "
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(Start: Header.offset, N: Header.size);
93 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
94 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
95 }
96 StringRef ObjectName = Parent->getFileName();
97 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
98
99 return IRObjectFile::create(Object: ObjBuffer, Context&: Ctx);
100}
101
102Expected<std::unique_ptr<Archive>>
103MachOUniversalBinary::ObjectForArch::getAsArchive() const {
104 if (!Parent)
105 report_fatal_error(reason: "MachOUniversalBinary::ObjectForArch::getAsArchive() "
106 "called when Parent is a nullptr");
107
108 StringRef ParentData = Parent->getData();
109 StringRef ObjectData;
110 if (Parent->getMagic() == MachO::FAT_MAGIC)
111 ObjectData = ParentData.substr(Start: Header.offset, N: Header.size);
112 else // Parent->getMagic() == MachO::FAT_MAGIC_64
113 ObjectData = ParentData.substr(Start: Header64.offset, N: Header64.size);
114 StringRef ObjectName = Parent->getFileName();
115 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
116 return Archive::create(Source: ObjBuffer);
117}
118
119void MachOUniversalBinary::anchor() { }
120
121Expected<std::unique_ptr<MachOUniversalBinary>>
122MachOUniversalBinary::create(MemoryBufferRef Source) {
123 Error Err = Error::success();
124 std::unique_ptr<MachOUniversalBinary> Ret(
125 new MachOUniversalBinary(Source, Err));
126 if (Err)
127 return std::move(Err);
128 return std::move(Ret);
129}
130
131MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
132 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
133 NumberOfObjects(0) {
134 ErrorAsOutParameter ErrAsOutParam(Err);
135 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
136 Err = make_error<GenericBinaryError>(Args: "File too small to be a Mach-O "
137 "universal file",
138 Args: object_error::invalid_file_type);
139 return;
140 }
141 // Check for magic value and sufficient header size.
142 StringRef Buf = getData();
143 MachO::fat_header H =
144 getUniversalBinaryStruct<MachO::fat_header>(Ptr: Buf.begin());
145 Magic = H.magic;
146 NumberOfObjects = H.nfat_arch;
147 if (NumberOfObjects == 0) {
148 Err = malformedError(Msg: "contains zero architecture types");
149 return;
150 }
151 uint32_t MinSize = sizeof(MachO::fat_header);
152 if (Magic == MachO::FAT_MAGIC)
153 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
154 else if (Magic == MachO::FAT_MAGIC_64)
155 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
156 else {
157 Err = malformedError(Msg: "bad magic number");
158 return;
159 }
160 if (Buf.size() < MinSize) {
161 Err = malformedError(Msg: "fat_arch" +
162 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
163 " structs would extend past the end of the file");
164 return;
165 }
166 for (uint32_t i = 0; i < NumberOfObjects; i++) {
167 ObjectForArch A(this, i);
168 uint64_t bigSize = A.getOffset();
169 bigSize += A.getSize();
170 if (bigSize > Buf.size()) {
171 Err = malformedError(Msg: "offset plus size of cputype (" +
172 Twine(A.getCPUType()) + ") cpusubtype (" +
173 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
174 ") extends past the end of the file");
175 return;
176 }
177
178 if (A.getAlign() > MaxSectionAlignment) {
179 Err = malformedError(Msg: "align (2^" + Twine(A.getAlign()) +
180 ") too large for cputype (" + Twine(A.getCPUType()) +
181 ") cpusubtype (" +
182 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
183 ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
184 return;
185 }
186 if(A.getOffset() % (1ull << A.getAlign()) != 0){
187 Err = malformedError(Msg: "offset: " + Twine(A.getOffset()) +
188 " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
189 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
190 ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
191 return;
192 }
193 if (A.getOffset() < MinSize) {
194 Err = malformedError(Msg: "cputype (" + Twine(A.getCPUType()) + ") "
195 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
196 ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
197 return;
198 }
199 }
200 for (uint32_t i = 0; i < NumberOfObjects; i++) {
201 ObjectForArch A(this, i);
202 for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
203 ObjectForArch B(this, j);
204 if (A.getCPUType() == B.getCPUType() &&
205 (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
206 (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
207 Err = malformedError(Msg: "contains two of the same architecture (cputype "
208 "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
209 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
210 return;
211 }
212 if ((A.getOffset() >= B.getOffset() &&
213 A.getOffset() < B.getOffset() + B.getSize()) ||
214 (A.getOffset() + A.getSize() > B.getOffset() &&
215 A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
216 (A.getOffset() <= B.getOffset() &&
217 A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
218 Err = malformedError(Msg: "cputype (" + Twine(A.getCPUType()) + ") "
219 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
220 ") at offset " + Twine(A.getOffset()) + " with a size of " +
221 Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
222 ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
223 + ") at offset " + Twine(B.getOffset()) + " with a size of "
224 + Twine(B.getSize()));
225 return;
226 }
227 }
228 }
229 Err = Error::success();
230}
231
232Expected<MachOUniversalBinary::ObjectForArch>
233MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
234 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
235 return make_error<GenericBinaryError>(Args: "Unknown architecture "
236 "named: " +
237 ArchName,
238 Args: object_error::arch_not_found);
239 for (const auto &Obj : objects())
240 if (Obj.getArchFlagName() == ArchName)
241 return Obj;
242 return make_error<GenericBinaryError>(Args: "fat file does not "
243 "contain " +
244 ArchName,
245 Args: object_error::arch_not_found);
246}
247
248Expected<std::unique_ptr<MachOObjectFile>>
249MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
250 Expected<ObjectForArch> O = getObjectForArch(ArchName);
251 if (!O)
252 return O.takeError();
253 return O->getAsObjectFile();
254}
255
256Expected<std::unique_ptr<IRObjectFile>>
257MachOUniversalBinary::getIRObjectForArch(StringRef ArchName,
258 LLVMContext &Ctx) const {
259 Expected<ObjectForArch> O = getObjectForArch(ArchName);
260 if (!O)
261 return O.takeError();
262 return O->getAsIRObject(Ctx);
263}
264
265Expected<std::unique_ptr<Archive>>
266MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
267 Expected<ObjectForArch> O = getObjectForArch(ArchName);
268 if (!O)
269 return O.takeError();
270 return O->getAsArchive();
271}
272