1 //===-- BinaryHolder.cpp --------------------------------------------------===//
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 program is a utility that aims to be a dropin replacement for
10 // Darwin's dsymutil.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "BinaryHolder.h"
15 #include "llvm/Object/MachO.h"
16 #include "llvm/Support/WithColor.h"
17 #include "llvm/Support/raw_ostream.h"
18
19 namespace llvm {
20 namespace dsymutil {
21
22 static std::pair<StringRef, StringRef>
getArchiveAndObjectName(StringRef Filename)23 getArchiveAndObjectName(StringRef Filename) {
24 StringRef Archive = Filename.substr(0, Filename.rfind('('));
25 StringRef Object = Filename.substr(Archive.size() + 1).drop_back();
26 return {Archive, Object};
27 }
28
isArchive(StringRef Filename)29 static bool isArchive(StringRef Filename) { return Filename.endswith(")"); }
30
31 static std::vector<MemoryBufferRef>
getMachOFatMemoryBuffers(StringRef Filename,MemoryBuffer & Mem,object::MachOUniversalBinary & Fat)32 getMachOFatMemoryBuffers(StringRef Filename, MemoryBuffer &Mem,
33 object::MachOUniversalBinary &Fat) {
34 std::vector<MemoryBufferRef> Buffers;
35 StringRef FatData = Fat.getData();
36 for (auto It = Fat.begin_objects(), End = Fat.end_objects(); It != End;
37 ++It) {
38 StringRef ObjData = FatData.substr(It->getOffset(), It->getSize());
39 Buffers.emplace_back(ObjData, Filename);
40 }
41 return Buffers;
42 }
43
load(IntrusiveRefCntPtr<vfs::FileSystem> VFS,StringRef Filename,TimestampTy Timestamp,bool Verbose)44 Error BinaryHolder::ArchiveEntry::load(IntrusiveRefCntPtr<vfs::FileSystem> VFS,
45 StringRef Filename,
46 TimestampTy Timestamp, bool Verbose) {
47 StringRef ArchiveFilename = getArchiveAndObjectName(Filename).first;
48
49 // Try to load archive and force it to be memory mapped.
50 auto ErrOrBuff = (ArchiveFilename == "-")
51 ? MemoryBuffer::getSTDIN()
52 : VFS->getBufferForFile(ArchiveFilename, -1, false);
53 if (auto Err = ErrOrBuff.getError())
54 return errorCodeToError(Err);
55
56 MemBuffer = std::move(*ErrOrBuff);
57
58 if (Verbose)
59 WithColor::note() << "loaded archive '" << ArchiveFilename << "'\n";
60
61 // Load one or more archive buffers, depending on whether we're dealing with
62 // a fat binary.
63 std::vector<MemoryBufferRef> ArchiveBuffers;
64
65 auto ErrOrFat =
66 object::MachOUniversalBinary::create(MemBuffer->getMemBufferRef());
67 if (!ErrOrFat) {
68 consumeError(ErrOrFat.takeError());
69 ArchiveBuffers.push_back(MemBuffer->getMemBufferRef());
70 } else {
71 FatBinary = std::move(*ErrOrFat);
72 FatBinaryName = std::string(ArchiveFilename);
73 ArchiveBuffers =
74 getMachOFatMemoryBuffers(FatBinaryName, *MemBuffer, *FatBinary);
75 }
76
77 // Finally, try to load the archives.
78 Archives.reserve(ArchiveBuffers.size());
79 for (auto MemRef : ArchiveBuffers) {
80 auto ErrOrArchive = object::Archive::create(MemRef);
81 if (!ErrOrArchive)
82 return ErrOrArchive.takeError();
83 Archives.push_back(std::move(*ErrOrArchive));
84 }
85
86 return Error::success();
87 }
88
load(IntrusiveRefCntPtr<vfs::FileSystem> VFS,StringRef Filename,TimestampTy Timestamp,bool Verbose)89 Error BinaryHolder::ObjectEntry::load(IntrusiveRefCntPtr<vfs::FileSystem> VFS,
90 StringRef Filename, TimestampTy Timestamp,
91 bool Verbose) {
92 // Try to load regular binary and force it to be memory mapped.
93 auto ErrOrBuff = (Filename == "-")
94 ? MemoryBuffer::getSTDIN()
95 : VFS->getBufferForFile(Filename, -1, false);
96 if (auto Err = ErrOrBuff.getError())
97 return errorCodeToError(Err);
98
99 if (Filename != "-" && Timestamp != sys::TimePoint<>()) {
100 llvm::ErrorOr<vfs::Status> Stat = VFS->status(Filename);
101 if (!Stat)
102 return errorCodeToError(Stat.getError());
103 if (Timestamp != std::chrono::time_point_cast<std::chrono::seconds>(
104 Stat->getLastModificationTime()))
105 WithColor::warning() << Filename
106 << ": timestamp mismatch between object file ("
107 << Stat->getLastModificationTime()
108 << ") and debug map (" << Timestamp << ")\n";
109 }
110
111 MemBuffer = std::move(*ErrOrBuff);
112
113 if (Verbose)
114 WithColor::note() << "loaded object.\n";
115
116 // Load one or more object buffers, depending on whether we're dealing with a
117 // fat binary.
118 std::vector<MemoryBufferRef> ObjectBuffers;
119
120 auto ErrOrFat =
121 object::MachOUniversalBinary::create(MemBuffer->getMemBufferRef());
122 if (!ErrOrFat) {
123 consumeError(ErrOrFat.takeError());
124 ObjectBuffers.push_back(MemBuffer->getMemBufferRef());
125 } else {
126 FatBinary = std::move(*ErrOrFat);
127 FatBinaryName = std::string(Filename);
128 ObjectBuffers =
129 getMachOFatMemoryBuffers(FatBinaryName, *MemBuffer, *FatBinary);
130 }
131
132 Objects.reserve(ObjectBuffers.size());
133 for (auto MemRef : ObjectBuffers) {
134 auto ErrOrObjectFile = object::ObjectFile::createObjectFile(MemRef);
135 if (!ErrOrObjectFile)
136 return ErrOrObjectFile.takeError();
137 Objects.push_back(std::move(*ErrOrObjectFile));
138 }
139
140 return Error::success();
141 }
142
143 std::vector<const object::ObjectFile *>
getObjects() const144 BinaryHolder::ObjectEntry::getObjects() const {
145 std::vector<const object::ObjectFile *> Result;
146 Result.reserve(Objects.size());
147 for (auto &Object : Objects) {
148 Result.push_back(Object.get());
149 }
150 return Result;
151 }
152 Expected<const object::ObjectFile &>
getObject(const Triple & T) const153 BinaryHolder::ObjectEntry::getObject(const Triple &T) const {
154 for (const auto &Obj : Objects) {
155 if (const auto *MachO = dyn_cast<object::MachOObjectFile>(Obj.get())) {
156 if (MachO->getArchTriple().str() == T.str())
157 return *MachO;
158 } else if (Obj->getArch() == T.getArch())
159 return *Obj;
160 }
161 return errorCodeToError(object::object_error::arch_not_found);
162 }
163
164 Expected<const BinaryHolder::ObjectEntry &>
getObjectEntry(StringRef Filename,TimestampTy Timestamp,bool Verbose)165 BinaryHolder::ArchiveEntry::getObjectEntry(StringRef Filename,
166 TimestampTy Timestamp,
167 bool Verbose) {
168 StringRef ArchiveFilename;
169 StringRef ObjectFilename;
170 std::tie(ArchiveFilename, ObjectFilename) = getArchiveAndObjectName(Filename);
171 KeyTy Key = {ObjectFilename, Timestamp};
172
173 // Try the cache first.
174 std::lock_guard<std::mutex> Lock(MemberCacheMutex);
175 if (MemberCache.count(Key))
176 return *MemberCache[Key];
177
178 // Create a new ObjectEntry, but don't add it to the cache yet. Loading of
179 // the archive members might fail and we don't want to lock the whole archive
180 // during this operation.
181 auto OE = std::make_unique<ObjectEntry>();
182
183 for (const auto &Archive : Archives) {
184 Error Err = Error::success();
185 for (auto Child : Archive->children(Err)) {
186 if (auto NameOrErr = Child.getName()) {
187 if (*NameOrErr == ObjectFilename) {
188 auto ModTimeOrErr = Child.getLastModified();
189 if (!ModTimeOrErr)
190 return ModTimeOrErr.takeError();
191
192 if (Timestamp != sys::TimePoint<>() &&
193 Timestamp != std::chrono::time_point_cast<std::chrono::seconds>(
194 ModTimeOrErr.get())) {
195 if (Verbose)
196 WithColor::warning()
197 << *NameOrErr
198 << ": timestamp mismatch between archive member ("
199 << ModTimeOrErr.get() << ") and debug map (" << Timestamp
200 << ")\n";
201 continue;
202 }
203
204 if (Verbose)
205 WithColor::note() << "found member in archive.\n";
206
207 auto ErrOrMem = Child.getMemoryBufferRef();
208 if (!ErrOrMem)
209 return ErrOrMem.takeError();
210
211 auto ErrOrObjectFile =
212 object::ObjectFile::createObjectFile(*ErrOrMem);
213 if (!ErrOrObjectFile)
214 return ErrOrObjectFile.takeError();
215
216 OE->Objects.push_back(std::move(*ErrOrObjectFile));
217 }
218 }
219 }
220 if (Err)
221 return std::move(Err);
222 }
223
224 if (OE->Objects.empty())
225 return errorCodeToError(errc::no_such_file_or_directory);
226
227 MemberCache[Key] = std::move(OE);
228 return *MemberCache[Key];
229 }
230
231 Expected<const BinaryHolder::ObjectEntry &>
getObjectEntry(StringRef Filename,TimestampTy Timestamp)232 BinaryHolder::getObjectEntry(StringRef Filename, TimestampTy Timestamp) {
233 if (Verbose)
234 WithColor::note() << "trying to open '" << Filename << "'\n";
235
236 // If this is an archive, we might have either the object or the archive
237 // cached. In this case we can load it without accessing the file system.
238 if (isArchive(Filename)) {
239 StringRef ArchiveFilename = getArchiveAndObjectName(Filename).first;
240 std::lock_guard<std::mutex> Lock(ArchiveCacheMutex);
241 if (ArchiveCache.count(ArchiveFilename)) {
242 return ArchiveCache[ArchiveFilename]->getObjectEntry(Filename, Timestamp,
243 Verbose);
244 } else {
245 auto AE = std::make_unique<ArchiveEntry>();
246 auto Err = AE->load(VFS, Filename, Timestamp, Verbose);
247 if (Err) {
248 // Don't return the error here: maybe the file wasn't an archive.
249 llvm::consumeError(std::move(Err));
250 } else {
251 ArchiveCache[ArchiveFilename] = std::move(AE);
252 return ArchiveCache[ArchiveFilename]->getObjectEntry(
253 Filename, Timestamp, Verbose);
254 }
255 }
256 }
257
258 // If this is an object, we might have it cached. If not we'll have to load
259 // it from the file system and cache it now.
260 std::lock_guard<std::mutex> Lock(ObjectCacheMutex);
261 if (!ObjectCache.count(Filename)) {
262 auto OE = std::make_unique<ObjectEntry>();
263 auto Err = OE->load(VFS, Filename, Timestamp, Verbose);
264 if (Err)
265 return std::move(Err);
266 ObjectCache[Filename] = std::move(OE);
267 }
268
269 return *ObjectCache[Filename];
270 }
271
clear()272 void BinaryHolder::clear() {
273 std::lock_guard<std::mutex> ArchiveLock(ArchiveCacheMutex);
274 std::lock_guard<std::mutex> ObjectLock(ObjectCacheMutex);
275 ArchiveCache.clear();
276 ObjectCache.clear();
277 }
278
279 } // namespace dsymutil
280 } // namespace llvm
281