1 //===-- ObjectContainerBSDArchive.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 #include "ObjectContainerBSDArchive.h"
10
11 #if defined(_WIN32) || defined(__ANDROID__)
12 // Defines from ar, missing on Windows
13 #define SARMAG 8
14 #define ARFMAG "`\n"
15
16 typedef struct ar_hdr {
17 char ar_name[16];
18 char ar_date[12];
19 char ar_uid[6], ar_gid[6];
20 char ar_mode[8];
21 char ar_size[10];
22 char ar_fmag[2];
23 } ar_hdr;
24 #else
25 #include <ar.h>
26 #endif
27
28 #include "lldb/Core/Module.h"
29 #include "lldb/Core/ModuleSpec.h"
30 #include "lldb/Core/PluginManager.h"
31 #include "lldb/Host/FileSystem.h"
32 #include "lldb/Symbol/ObjectFile.h"
33 #include "lldb/Utility/ArchSpec.h"
34 #include "lldb/Utility/LLDBLog.h"
35 #include "lldb/Utility/Stream.h"
36 #include "lldb/Utility/Timer.h"
37
38 #include "llvm/Object/Archive.h"
39 #include "llvm/Support/MemoryBuffer.h"
40
41 using namespace lldb;
42 using namespace lldb_private;
43
44 using namespace llvm::object;
45
LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive)46 LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive)
47
48 ObjectContainerBSDArchive::Object::Object() : ar_name() {}
49
Clear()50 void ObjectContainerBSDArchive::Object::Clear() {
51 ar_name.Clear();
52 modification_time = 0;
53 size = 0;
54 file_offset = 0;
55 file_size = 0;
56 }
57
Dump() const58 void ObjectContainerBSDArchive::Object::Dump() const {
59 printf("name = \"%s\"\n", ar_name.GetCString());
60 printf("mtime = 0x%8.8" PRIx32 "\n", modification_time);
61 printf("size = 0x%8.8" PRIx32 " (%" PRIu32 ")\n", size, size);
62 printf("file_offset = 0x%16.16" PRIx64 " (%" PRIu64 ")\n", file_offset,
63 file_offset);
64 printf("file_size = 0x%16.16" PRIx64 " (%" PRIu64 ")\n\n", file_size,
65 file_size);
66 }
67
Archive(const lldb_private::ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset,lldb_private::DataExtractor & data,ArchiveType archive_type)68 ObjectContainerBSDArchive::Archive::Archive(const lldb_private::ArchSpec &arch,
69 const llvm::sys::TimePoint<> &time,
70 lldb::offset_t file_offset,
71 lldb_private::DataExtractor &data,
72 ArchiveType archive_type)
73 : m_arch(arch), m_modification_time(time), m_file_offset(file_offset),
74 m_objects(), m_data(data), m_archive_type(archive_type) {}
75
76 Log *l = GetLog(LLDBLog::Object);
77 ObjectContainerBSDArchive::Archive::~Archive() = default;
78
ParseObjects()79 size_t ObjectContainerBSDArchive::Archive::ParseObjects() {
80 DataExtractor &data = m_data;
81
82 std::unique_ptr<llvm::MemoryBuffer> mem_buffer =
83 llvm::MemoryBuffer::getMemBuffer(
84 llvm::StringRef((const char *)data.GetDataStart(),
85 data.GetByteSize()),
86 llvm::StringRef(),
87 /*RequiresNullTerminator=*/false);
88
89 auto exp_ar = llvm::object::Archive::create(mem_buffer->getMemBufferRef());
90 if (!exp_ar) {
91 LLDB_LOG_ERROR(l, exp_ar.takeError(), "failed to create archive: {0}");
92 return 0;
93 }
94 auto llvm_archive = std::move(exp_ar.get());
95
96 llvm::Error iter_err = llvm::Error::success();
97 Object obj;
98 for (const auto &child: llvm_archive->children(iter_err)) {
99 obj.Clear();
100 auto exp_name = child.getName();
101 if (exp_name) {
102 obj.ar_name = ConstString(exp_name.get());
103 } else {
104 LLDB_LOG_ERROR(l, exp_name.takeError(),
105 "failed to get archive object name: {0}");
106 continue;
107 }
108
109 auto exp_mtime = child.getLastModified();
110 if (exp_mtime) {
111 obj.modification_time =
112 std::chrono::duration_cast<std::chrono::seconds>(
113 std::chrono::time_point_cast<std::chrono::seconds>(
114 exp_mtime.get()).time_since_epoch()).count();
115 } else {
116 LLDB_LOG_ERROR(l, exp_mtime.takeError(),
117 "failed to get archive object time: {0}");
118 continue;
119 }
120
121 auto exp_size = child.getRawSize();
122 if (exp_size) {
123 obj.size = exp_size.get();
124 } else {
125 LLDB_LOG_ERROR(l, exp_size.takeError(),
126 "failed to get archive object size: {0}");
127 continue;
128 }
129
130 obj.file_offset = child.getDataOffset();
131
132 auto exp_file_size = child.getSize();
133 if (exp_file_size) {
134 obj.file_size = exp_file_size.get();
135 } else {
136 LLDB_LOG_ERROR(l, exp_file_size.takeError(),
137 "failed to get archive object file size: {0}");
138 continue;
139 }
140 m_object_name_to_index_map.Append(obj.ar_name, m_objects.size());
141 m_objects.push_back(obj);
142 }
143 if (iter_err) {
144 LLDB_LOG_ERROR(l, std::move(iter_err),
145 "failed to iterate over archive objects: {0}");
146 }
147 // Now sort all of the object name pointers
148 m_object_name_to_index_map.Sort();
149 return m_objects.size();
150 }
151
152 ObjectContainerBSDArchive::Object *
FindObject(ConstString object_name,const llvm::sys::TimePoint<> & object_mod_time)153 ObjectContainerBSDArchive::Archive::FindObject(
154 ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) {
155 const ObjectNameToIndexMap::Entry *match =
156 m_object_name_to_index_map.FindFirstValueForName(object_name);
157 if (!match)
158 return nullptr;
159 if (object_mod_time == llvm::sys::TimePoint<>())
160 return &m_objects[match->value];
161
162 const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time);
163 if (m_objects[match->value].modification_time == object_modification_date)
164 return &m_objects[match->value];
165
166 const ObjectNameToIndexMap::Entry *next_match =
167 m_object_name_to_index_map.FindNextValueForName(match);
168 while (next_match) {
169 if (m_objects[next_match->value].modification_time ==
170 object_modification_date)
171 return &m_objects[next_match->value];
172 next_match = m_object_name_to_index_map.FindNextValueForName(next_match);
173 }
174
175 return nullptr;
176 }
177
178 ObjectContainerBSDArchive::Archive::shared_ptr
FindCachedArchive(const FileSpec & file,const ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset)179 ObjectContainerBSDArchive::Archive::FindCachedArchive(
180 const FileSpec &file, const ArchSpec &arch,
181 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) {
182 std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex());
183 shared_ptr archive_sp;
184 Archive::Map &archive_map = Archive::GetArchiveCache();
185 Archive::Map::iterator pos = archive_map.find(file);
186 // Don't cache a value for "archive_map.end()" below since we might delete an
187 // archive entry...
188 while (pos != archive_map.end() && pos->first == file) {
189 bool match = true;
190 if (arch.IsValid() &&
191 !pos->second->GetArchitecture().IsCompatibleMatch(arch))
192 match = false;
193 else if (file_offset != LLDB_INVALID_OFFSET &&
194 pos->second->GetFileOffset() != file_offset)
195 match = false;
196 if (match) {
197 if (pos->second->GetModificationTime() == time) {
198 return pos->second;
199 } else {
200 // We have a file at the same path with the same architecture whose
201 // modification time doesn't match. It doesn't make sense for us to
202 // continue to use this BSD archive since we cache only the object info
203 // which consists of file time info and also the file offset and file
204 // size of any contained objects. Since this information is now out of
205 // date, we won't get the correct information if we go and extract the
206 // file data, so we should remove the old and outdated entry.
207 archive_map.erase(pos);
208 pos = archive_map.find(file);
209 continue; // Continue to next iteration so we don't increment pos
210 // below...
211 }
212 }
213 ++pos;
214 }
215 return archive_sp;
216 }
217
218 ObjectContainerBSDArchive::Archive::shared_ptr
ParseAndCacheArchiveForFile(const FileSpec & file,const ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset,DataExtractor & data,ArchiveType archive_type)219 ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile(
220 const FileSpec &file, const ArchSpec &arch,
221 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset,
222 DataExtractor &data, ArchiveType archive_type) {
223 shared_ptr archive_sp(
224 new Archive(arch, time, file_offset, data, archive_type));
225 if (archive_sp) {
226 const size_t num_objects = archive_sp->ParseObjects();
227 if (num_objects > 0) {
228 std::lock_guard<std::recursive_mutex> guard(
229 Archive::GetArchiveCacheMutex());
230 Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp));
231 } else {
232 archive_sp.reset();
233 }
234 }
235 return archive_sp;
236 }
237
238 ObjectContainerBSDArchive::Archive::Map &
GetArchiveCache()239 ObjectContainerBSDArchive::Archive::GetArchiveCache() {
240 static Archive::Map g_archive_map;
241 return g_archive_map;
242 }
243
244 std::recursive_mutex &
GetArchiveCacheMutex()245 ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() {
246 static std::recursive_mutex g_archive_map_mutex;
247 return g_archive_map_mutex;
248 }
249
Initialize()250 void ObjectContainerBSDArchive::Initialize() {
251 PluginManager::RegisterPlugin(GetPluginNameStatic(),
252 GetPluginDescriptionStatic(), CreateInstance,
253 GetModuleSpecifications);
254 }
255
Terminate()256 void ObjectContainerBSDArchive::Terminate() {
257 PluginManager::UnregisterPlugin(CreateInstance);
258 }
259
CreateInstance(const lldb::ModuleSP & module_sp,DataBufferSP & data_sp,lldb::offset_t data_offset,const FileSpec * file,lldb::offset_t file_offset,lldb::offset_t length)260 ObjectContainer *ObjectContainerBSDArchive::CreateInstance(
261 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
262 lldb::offset_t data_offset, const FileSpec *file,
263 lldb::offset_t file_offset, lldb::offset_t length) {
264 ConstString object_name(module_sp->GetObjectName());
265 if (!object_name)
266 return nullptr;
267
268 if (data_sp) {
269 // We have data, which means this is the first 512 bytes of the file Check
270 // to see if the magic bytes match and if they do, read the entire table of
271 // contents for the archive and cache it
272 DataExtractor data;
273 data.SetData(data_sp, data_offset, length);
274 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data);
275 if (file && data_sp && archive_type != ArchiveType::Invalid) {
276 LLDB_SCOPED_TIMERF(
277 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = "
278 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
279 module_sp->GetFileSpec().GetPath().c_str(),
280 static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
281 static_cast<uint64_t>(length));
282
283 // Map the entire .a file to be sure that we don't lose any data if the
284 // file gets updated by a new build while this .a file is being used for
285 // debugging
286 DataBufferSP archive_data_sp =
287 FileSystem::Instance().CreateDataBuffer(*file, length, file_offset);
288 if (!archive_data_sp)
289 return nullptr;
290
291 lldb::offset_t archive_data_offset = 0;
292
293 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
294 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
295 file_offset));
296 std::unique_ptr<ObjectContainerBSDArchive> container_up(
297 new ObjectContainerBSDArchive(module_sp, archive_data_sp,
298 archive_data_offset, file, file_offset,
299 length, archive_type));
300
301 if (container_up) {
302 if (archive_sp) {
303 // We already have this archive in our cache, use it
304 container_up->SetArchive(archive_sp);
305 return container_up.release();
306 } else if (container_up->ParseHeader())
307 return container_up.release();
308 }
309 }
310 } else {
311 // No data, just check for a cached archive
312 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
313 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
314 file_offset));
315 if (archive_sp) {
316 std::unique_ptr<ObjectContainerBSDArchive> container_up(
317 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file,
318 file_offset, length,
319 archive_sp->GetArchiveType()));
320
321 if (container_up) {
322 // We already have this archive in our cache, use it
323 container_up->SetArchive(archive_sp);
324 return container_up.release();
325 }
326 }
327 }
328 return nullptr;
329 }
330
331 ArchiveType
MagicBytesMatch(const DataExtractor & data)332 ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) {
333 uint32_t offset = 0;
334 const char *armag = (const char *)data.PeekData(offset,
335 sizeof(ar_hdr) + SARMAG);
336 if (armag == nullptr)
337 return ArchiveType::Invalid;
338 ArchiveType result = ArchiveType::Invalid;
339 if (strncmp(armag, ArchiveMagic, SARMAG) == 0)
340 result = ArchiveType::Archive;
341 else if (strncmp(armag, ThinArchiveMagic, SARMAG) == 0)
342 result = ArchiveType::ThinArchive;
343 else
344 return ArchiveType::Invalid;
345
346 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
347 if (strncmp(armag, ARFMAG, 2) == 0)
348 return result;
349 return ArchiveType::Invalid;
350 }
351
ObjectContainerBSDArchive(const lldb::ModuleSP & module_sp,DataBufferSP & data_sp,lldb::offset_t data_offset,const lldb_private::FileSpec * file,lldb::offset_t file_offset,lldb::offset_t size,ArchiveType archive_type)352 ObjectContainerBSDArchive::ObjectContainerBSDArchive(
353 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
354 lldb::offset_t data_offset, const lldb_private::FileSpec *file,
355 lldb::offset_t file_offset, lldb::offset_t size, ArchiveType archive_type)
356 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset),
357 m_archive_sp() {
358 m_archive_type = archive_type;
359 }
360
SetArchive(Archive::shared_ptr & archive_sp)361 void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) {
362 m_archive_sp = archive_sp;
363 }
364
365 ObjectContainerBSDArchive::~ObjectContainerBSDArchive() = default;
366
ParseHeader()367 bool ObjectContainerBSDArchive::ParseHeader() {
368 if (m_archive_sp.get() == nullptr) {
369 if (m_data.GetByteSize() > 0) {
370 ModuleSP module_sp(GetModule());
371 if (module_sp) {
372 m_archive_sp = Archive::ParseAndCacheArchiveForFile(
373 m_file, module_sp->GetArchitecture(),
374 module_sp->GetModificationTime(), m_offset, m_data, m_archive_type);
375 }
376 // Clear the m_data that contains the entire archive data and let our
377 // m_archive_sp hold onto the data.
378 m_data.Clear();
379 }
380 }
381 return m_archive_sp.get() != nullptr;
382 }
383
GetChildFileSpecificationsFromThin(llvm::StringRef childPath,const FileSpec & parentFileSpec)384 FileSpec GetChildFileSpecificationsFromThin(llvm::StringRef childPath,
385 const FileSpec &parentFileSpec) {
386 llvm::SmallString<128> FullPath;
387 if (llvm::sys::path::is_absolute(childPath)) {
388 FullPath = childPath;
389 } else {
390 FullPath = parentFileSpec.GetDirectory().GetStringRef();
391 llvm::sys::path::append(FullPath, childPath);
392 }
393 FileSpec child = FileSpec(FullPath.str(), llvm::sys::path::Style::posix);
394 return child;
395 }
396
GetObjectFile(const FileSpec * file)397 ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) {
398 ModuleSP module_sp(GetModule());
399 if (module_sp) {
400 if (module_sp->GetObjectName() && m_archive_sp) {
401 Object *object = m_archive_sp->FindObject(
402 module_sp->GetObjectName(), module_sp->GetObjectModificationTime());
403 if (object) {
404 if (m_archive_type == ArchiveType::ThinArchive) {
405 // Set file to child object file
406 FileSpec child = GetChildFileSpecificationsFromThin(
407 object->ar_name.GetStringRef(), m_file);
408 lldb::offset_t file_offset = 0;
409 lldb::offset_t file_size = object->size;
410 std::shared_ptr<DataBuffer> child_data_sp =
411 FileSystem::Instance().CreateDataBuffer(child, file_size,
412 file_offset);
413 if (!child_data_sp ||
414 child_data_sp->GetByteSize() != object->file_size)
415 return ObjectFileSP();
416 lldb::offset_t data_offset = 0;
417 return ObjectFile::FindPlugin(
418 module_sp, &child, m_offset + object->file_offset,
419 object->file_size, child_data_sp, data_offset);
420 }
421 lldb::offset_t data_offset = object->file_offset;
422 return ObjectFile::FindPlugin(
423 module_sp, file, m_offset + object->file_offset, object->file_size,
424 m_archive_sp->GetData().GetSharedDataBuffer(), data_offset);
425 }
426 }
427 }
428 return ObjectFileSP();
429 }
430
GetModuleSpecifications(const lldb_private::FileSpec & file,lldb::DataBufferSP & data_sp,lldb::offset_t data_offset,lldb::offset_t file_offset,lldb::offset_t file_size,lldb_private::ModuleSpecList & specs)431 size_t ObjectContainerBSDArchive::GetModuleSpecifications(
432 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
433 lldb::offset_t data_offset, lldb::offset_t file_offset,
434 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) {
435
436 // We have data, which means this is the first 512 bytes of the file Check to
437 // see if the magic bytes match and if they do, read the entire table of
438 // contents for the archive and cache it
439 DataExtractor data;
440 data.SetData(data_sp, data_offset, data_sp->GetByteSize());
441 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data);
442 if (!file || !data_sp || archive_type == ArchiveType::Invalid)
443 return 0;
444
445 const size_t initial_count = specs.GetSize();
446 llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file);
447 Archive::shared_ptr archive_sp(
448 Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset));
449 bool set_archive_arch = false;
450 if (!archive_sp) {
451 set_archive_arch = true;
452 data_sp =
453 FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset);
454 if (data_sp) {
455 data.SetData(data_sp, 0, data_sp->GetByteSize());
456 archive_sp = Archive::ParseAndCacheArchiveForFile(
457 file, ArchSpec(), file_mod_time, file_offset, data, archive_type);
458 }
459 }
460
461 if (archive_sp) {
462 const size_t num_objects = archive_sp->GetNumObjects();
463 for (size_t idx = 0; idx < num_objects; ++idx) {
464 const Object *object = archive_sp->GetObjectAtIndex(idx);
465 if (object) {
466 if (archive_sp->GetArchiveType() == ArchiveType::ThinArchive) {
467 if (object->ar_name.IsEmpty())
468 continue;
469 FileSpec child = GetChildFileSpecificationsFromThin(
470 object->ar_name.GetStringRef(), file);
471 if (ObjectFile::GetModuleSpecifications(child, 0, object->file_size,
472 specs)) {
473 ModuleSpec &spec =
474 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1);
475 llvm::sys::TimePoint<> object_mod_time(
476 std::chrono::seconds(object->modification_time));
477 spec.GetObjectName() = object->ar_name;
478 spec.SetObjectOffset(0);
479 spec.SetObjectSize(object->file_size);
480 spec.GetObjectModificationTime() = object_mod_time;
481 }
482 continue;
483 }
484 const lldb::offset_t object_file_offset =
485 file_offset + object->file_offset;
486 if (object->file_offset < file_size && file_size > object_file_offset) {
487 if (ObjectFile::GetModuleSpecifications(
488 file, object_file_offset, file_size - object_file_offset,
489 specs)) {
490 ModuleSpec &spec =
491 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1);
492 llvm::sys::TimePoint<> object_mod_time(
493 std::chrono::seconds(object->modification_time));
494 spec.GetObjectName() = object->ar_name;
495 spec.SetObjectOffset(object_file_offset);
496 spec.SetObjectSize(object->file_size);
497 spec.GetObjectModificationTime() = object_mod_time;
498 }
499 }
500 }
501 }
502 }
503 const size_t end_count = specs.GetSize();
504 size_t num_specs_added = end_count - initial_count;
505 if (set_archive_arch && num_specs_added > 0) {
506 // The archive was created but we didn't have an architecture so we need to
507 // set it
508 for (size_t i = initial_count; i < end_count; ++i) {
509 ModuleSpec module_spec;
510 if (specs.GetModuleSpecAtIndex(i, module_spec)) {
511 if (module_spec.GetArchitecture().IsValid()) {
512 archive_sp->SetArchitecture(module_spec.GetArchitecture());
513 break;
514 }
515 }
516 }
517 }
518 return num_specs_added;
519 }
520