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 ARMAG "!<arch>\n"
14 #define SARMAG 8
15 #define ARFMAG "`\n"
16
17 typedef struct ar_hdr {
18 char ar_name[16];
19 char ar_date[12];
20 char ar_uid[6], ar_gid[6];
21 char ar_mode[8];
22 char ar_size[10];
23 char ar_fmag[2];
24 } ar_hdr;
25 #else
26 #include <ar.h>
27 #endif
28
29 #include "lldb/Core/Module.h"
30 #include "lldb/Core/ModuleSpec.h"
31 #include "lldb/Core/PluginManager.h"
32 #include "lldb/Host/FileSystem.h"
33 #include "lldb/Symbol/ObjectFile.h"
34 #include "lldb/Utility/ArchSpec.h"
35 #include "lldb/Utility/Stream.h"
36 #include "lldb/Utility/Timer.h"
37
38 #include "llvm/Support/MemoryBuffer.h"
39
40 using namespace lldb;
41 using namespace lldb_private;
42
LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive)43 LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive)
44
45 ObjectContainerBSDArchive::Object::Object() : ar_name() {}
46
Clear()47 void ObjectContainerBSDArchive::Object::Clear() {
48 ar_name.Clear();
49 modification_time = 0;
50 uid = 0;
51 gid = 0;
52 mode = 0;
53 size = 0;
54 file_offset = 0;
55 file_size = 0;
56 }
57
58 lldb::offset_t
Extract(const DataExtractor & data,lldb::offset_t offset)59 ObjectContainerBSDArchive::Object::Extract(const DataExtractor &data,
60 lldb::offset_t offset) {
61 size_t ar_name_len = 0;
62 std::string str;
63 char *err;
64
65 // File header
66 //
67 // The common format is as follows.
68 //
69 // Offset Length Name Format
70 // 0 16 File name ASCII right padded with spaces (no spaces
71 // allowed in file name)
72 // 16 12 File mod Decimal as cstring right padded with
73 // spaces
74 // 28 6 Owner ID Decimal as cstring right padded with
75 // spaces
76 // 34 6 Group ID Decimal as cstring right padded with
77 // spaces
78 // 40 8 File mode Octal as cstring right padded with
79 // spaces
80 // 48 10 File byte size Decimal as cstring right padded with
81 // spaces
82 // 58 2 File magic 0x60 0x0A
83
84 // Make sure there is enough data for the file header and bail if not
85 if (!data.ValidOffsetForDataOfSize(offset, 60))
86 return LLDB_INVALID_OFFSET;
87
88 str.assign((const char *)data.GetData(&offset, 16), 16);
89 if (llvm::StringRef(str).startswith("#1/")) {
90 // If the name is longer than 16 bytes, or contains an embedded space then
91 // it will use this format where the length of the name is here and the
92 // name characters are after this header.
93 ar_name_len = strtoul(str.c_str() + 3, &err, 10);
94 } else {
95 // Strip off any trailing spaces.
96 const size_t last_pos = str.find_last_not_of(' ');
97 if (last_pos != std::string::npos) {
98 if (last_pos + 1 < 16)
99 str.erase(last_pos + 1);
100 }
101 ar_name.SetCString(str.c_str());
102 }
103
104 str.assign((const char *)data.GetData(&offset, 12), 12);
105 modification_time = strtoul(str.c_str(), &err, 10);
106
107 str.assign((const char *)data.GetData(&offset, 6), 6);
108 uid = strtoul(str.c_str(), &err, 10);
109
110 str.assign((const char *)data.GetData(&offset, 6), 6);
111 gid = strtoul(str.c_str(), &err, 10);
112
113 str.assign((const char *)data.GetData(&offset, 8), 8);
114 mode = strtoul(str.c_str(), &err, 8);
115
116 str.assign((const char *)data.GetData(&offset, 10), 10);
117 size = strtoul(str.c_str(), &err, 10);
118
119 str.assign((const char *)data.GetData(&offset, 2), 2);
120 if (str == ARFMAG) {
121 if (ar_name_len > 0) {
122 const void *ar_name_ptr = data.GetData(&offset, ar_name_len);
123 // Make sure there was enough data for the string value and bail if not
124 if (ar_name_ptr == nullptr)
125 return LLDB_INVALID_OFFSET;
126 str.assign((const char *)ar_name_ptr, ar_name_len);
127 ar_name.SetCString(str.c_str());
128 }
129 file_offset = offset;
130 file_size = size - ar_name_len;
131 return offset;
132 }
133 return LLDB_INVALID_OFFSET;
134 }
135
Archive(const lldb_private::ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset,lldb_private::DataExtractor & data)136 ObjectContainerBSDArchive::Archive::Archive(const lldb_private::ArchSpec &arch,
137 const llvm::sys::TimePoint<> &time,
138 lldb::offset_t file_offset,
139 lldb_private::DataExtractor &data)
140 : m_arch(arch), m_modification_time(time), m_file_offset(file_offset),
141 m_objects(), m_data(data) {}
142
143 ObjectContainerBSDArchive::Archive::~Archive() = default;
144
ParseObjects()145 size_t ObjectContainerBSDArchive::Archive::ParseObjects() {
146 DataExtractor &data = m_data;
147 std::string str;
148 lldb::offset_t offset = 0;
149 str.assign((const char *)data.GetData(&offset, SARMAG), SARMAG);
150 if (str == ARMAG) {
151 Object obj;
152 do {
153 offset = obj.Extract(data, offset);
154 if (offset == LLDB_INVALID_OFFSET)
155 break;
156 size_t obj_idx = m_objects.size();
157 m_objects.push_back(obj);
158 // Insert all of the C strings out of order for now...
159 m_object_name_to_index_map.Append(obj.ar_name, obj_idx);
160 offset += obj.file_size;
161 obj.Clear();
162 } while (data.ValidOffset(offset));
163
164 // Now sort all of the object name pointers
165 m_object_name_to_index_map.Sort();
166 }
167 return m_objects.size();
168 }
169
170 ObjectContainerBSDArchive::Object *
FindObject(ConstString object_name,const llvm::sys::TimePoint<> & object_mod_time)171 ObjectContainerBSDArchive::Archive::FindObject(
172 ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) {
173 const ObjectNameToIndexMap::Entry *match =
174 m_object_name_to_index_map.FindFirstValueForName(object_name);
175 if (!match)
176 return nullptr;
177 if (object_mod_time == llvm::sys::TimePoint<>())
178 return &m_objects[match->value];
179
180 const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time);
181 if (m_objects[match->value].modification_time == object_modification_date)
182 return &m_objects[match->value];
183
184 const ObjectNameToIndexMap::Entry *next_match =
185 m_object_name_to_index_map.FindNextValueForName(match);
186 while (next_match) {
187 if (m_objects[next_match->value].modification_time ==
188 object_modification_date)
189 return &m_objects[next_match->value];
190 next_match = m_object_name_to_index_map.FindNextValueForName(next_match);
191 }
192
193 return nullptr;
194 }
195
196 ObjectContainerBSDArchive::Archive::shared_ptr
FindCachedArchive(const FileSpec & file,const ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset)197 ObjectContainerBSDArchive::Archive::FindCachedArchive(
198 const FileSpec &file, const ArchSpec &arch,
199 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) {
200 std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex());
201 shared_ptr archive_sp;
202 Archive::Map &archive_map = Archive::GetArchiveCache();
203 Archive::Map::iterator pos = archive_map.find(file);
204 // Don't cache a value for "archive_map.end()" below since we might delete an
205 // archive entry...
206 while (pos != archive_map.end() && pos->first == file) {
207 bool match = true;
208 if (arch.IsValid() &&
209 !pos->second->GetArchitecture().IsCompatibleMatch(arch))
210 match = false;
211 else if (file_offset != LLDB_INVALID_OFFSET &&
212 pos->second->GetFileOffset() != file_offset)
213 match = false;
214 if (match) {
215 if (pos->second->GetModificationTime() == time) {
216 return pos->second;
217 } else {
218 // We have a file at the same path with the same architecture whose
219 // modification time doesn't match. It doesn't make sense for us to
220 // continue to use this BSD archive since we cache only the object info
221 // which consists of file time info and also the file offset and file
222 // size of any contained objects. Since this information is now out of
223 // date, we won't get the correct information if we go and extract the
224 // file data, so we should remove the old and outdated entry.
225 archive_map.erase(pos);
226 pos = archive_map.find(file);
227 continue; // Continue to next iteration so we don't increment pos
228 // below...
229 }
230 }
231 ++pos;
232 }
233 return archive_sp;
234 }
235
236 ObjectContainerBSDArchive::Archive::shared_ptr
ParseAndCacheArchiveForFile(const FileSpec & file,const ArchSpec & arch,const llvm::sys::TimePoint<> & time,lldb::offset_t file_offset,DataExtractor & data)237 ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile(
238 const FileSpec &file, const ArchSpec &arch,
239 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset,
240 DataExtractor &data) {
241 shared_ptr archive_sp(new Archive(arch, time, file_offset, data));
242 if (archive_sp) {
243 const size_t num_objects = archive_sp->ParseObjects();
244 if (num_objects > 0) {
245 std::lock_guard<std::recursive_mutex> guard(
246 Archive::GetArchiveCacheMutex());
247 Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp));
248 } else {
249 archive_sp.reset();
250 }
251 }
252 return archive_sp;
253 }
254
255 ObjectContainerBSDArchive::Archive::Map &
GetArchiveCache()256 ObjectContainerBSDArchive::Archive::GetArchiveCache() {
257 static Archive::Map g_archive_map;
258 return g_archive_map;
259 }
260
261 std::recursive_mutex &
GetArchiveCacheMutex()262 ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() {
263 static std::recursive_mutex g_archive_map_mutex;
264 return g_archive_map_mutex;
265 }
266
Initialize()267 void ObjectContainerBSDArchive::Initialize() {
268 PluginManager::RegisterPlugin(GetPluginNameStatic(),
269 GetPluginDescriptionStatic(), CreateInstance,
270 GetModuleSpecifications);
271 }
272
Terminate()273 void ObjectContainerBSDArchive::Terminate() {
274 PluginManager::UnregisterPlugin(CreateInstance);
275 }
276
GetPluginNameStatic()277 lldb_private::ConstString ObjectContainerBSDArchive::GetPluginNameStatic() {
278 static ConstString g_name("bsd-archive");
279 return g_name;
280 }
281
GetPluginDescriptionStatic()282 const char *ObjectContainerBSDArchive::GetPluginDescriptionStatic() {
283 return "BSD Archive object container reader.";
284 }
285
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)286 ObjectContainer *ObjectContainerBSDArchive::CreateInstance(
287 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
288 lldb::offset_t data_offset, const FileSpec *file,
289 lldb::offset_t file_offset, lldb::offset_t length) {
290 ConstString object_name(module_sp->GetObjectName());
291 if (!object_name)
292 return nullptr;
293
294 if (data_sp) {
295 // We have data, which means this is the first 512 bytes of the file Check
296 // to see if the magic bytes match and if they do, read the entire table of
297 // contents for the archive and cache it
298 DataExtractor data;
299 data.SetData(data_sp, data_offset, length);
300 if (file && data_sp && ObjectContainerBSDArchive::MagicBytesMatch(data)) {
301 LLDB_SCOPED_TIMERF(
302 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = "
303 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
304 module_sp->GetFileSpec().GetPath().c_str(),
305 static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
306 static_cast<uint64_t>(length));
307
308 // Map the entire .a file to be sure that we don't lose any data if the
309 // file gets updated by a new build while this .a file is being used for
310 // debugging
311 DataBufferSP archive_data_sp =
312 FileSystem::Instance().CreateDataBuffer(*file, length, file_offset);
313 if (!archive_data_sp)
314 return nullptr;
315
316 lldb::offset_t archive_data_offset = 0;
317
318 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
319 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
320 file_offset));
321 std::unique_ptr<ObjectContainerBSDArchive> container_up(
322 new ObjectContainerBSDArchive(module_sp, archive_data_sp,
323 archive_data_offset, file, file_offset,
324 length));
325
326 if (container_up) {
327 if (archive_sp) {
328 // We already have this archive in our cache, use it
329 container_up->SetArchive(archive_sp);
330 return container_up.release();
331 } else if (container_up->ParseHeader())
332 return container_up.release();
333 }
334 }
335 } else {
336 // No data, just check for a cached archive
337 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
338 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
339 file_offset));
340 if (archive_sp) {
341 std::unique_ptr<ObjectContainerBSDArchive> container_up(
342 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file,
343 file_offset, length));
344
345 if (container_up) {
346 // We already have this archive in our cache, use it
347 container_up->SetArchive(archive_sp);
348 return container_up.release();
349 }
350 }
351 }
352 return nullptr;
353 }
354
MagicBytesMatch(const DataExtractor & data)355 bool ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) {
356 uint32_t offset = 0;
357 const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr));
358 if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) {
359 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
360 if (strncmp(armag, ARFMAG, 2) == 0)
361 return true;
362 }
363 return false;
364 }
365
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)366 ObjectContainerBSDArchive::ObjectContainerBSDArchive(
367 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
368 lldb::offset_t data_offset, const lldb_private::FileSpec *file,
369 lldb::offset_t file_offset, lldb::offset_t size)
370 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset),
371 m_archive_sp() {}
SetArchive(Archive::shared_ptr & archive_sp)372 void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) {
373 m_archive_sp = archive_sp;
374 }
375
376 ObjectContainerBSDArchive::~ObjectContainerBSDArchive() = default;
377
ParseHeader()378 bool ObjectContainerBSDArchive::ParseHeader() {
379 if (m_archive_sp.get() == nullptr) {
380 if (m_data.GetByteSize() > 0) {
381 ModuleSP module_sp(GetModule());
382 if (module_sp) {
383 m_archive_sp = Archive::ParseAndCacheArchiveForFile(
384 m_file, module_sp->GetArchitecture(),
385 module_sp->GetModificationTime(), m_offset, m_data);
386 }
387 // Clear the m_data that contains the entire archive data and let our
388 // m_archive_sp hold onto the data.
389 m_data.Clear();
390 }
391 }
392 return m_archive_sp.get() != nullptr;
393 }
394
Dump(Stream * s) const395 void ObjectContainerBSDArchive::Dump(Stream *s) const {
396 s->Printf("%p: ", static_cast<const void *>(this));
397 s->Indent();
398 const size_t num_archs = GetNumArchitectures();
399 const size_t num_objects = GetNumObjects();
400 s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64
401 ", num_objects = %" PRIu64 "",
402 (uint64_t)num_archs, (uint64_t)num_objects);
403 uint32_t i;
404 ArchSpec arch;
405 s->IndentMore();
406 for (i = 0; i < num_archs; i++) {
407 s->Indent();
408 GetArchitectureAtIndex(i, arch);
409 s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName());
410 }
411 for (i = 0; i < num_objects; i++) {
412 s->Indent();
413 s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i));
414 }
415 s->IndentLess();
416 s->EOL();
417 }
418
GetObjectFile(const FileSpec * file)419 ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) {
420 ModuleSP module_sp(GetModule());
421 if (module_sp) {
422 if (module_sp->GetObjectName() && m_archive_sp) {
423 Object *object = m_archive_sp->FindObject(
424 module_sp->GetObjectName(), module_sp->GetObjectModificationTime());
425 if (object) {
426 lldb::offset_t data_offset = object->file_offset;
427 return ObjectFile::FindPlugin(
428 module_sp, file, m_offset + object->file_offset, object->file_size,
429 m_archive_sp->GetData().GetSharedDataBuffer(), data_offset);
430 }
431 }
432 }
433 return ObjectFileSP();
434 }
435
436 // PluginInterface protocol
GetPluginName()437 lldb_private::ConstString ObjectContainerBSDArchive::GetPluginName() {
438 return GetPluginNameStatic();
439 }
440
GetPluginVersion()441 uint32_t ObjectContainerBSDArchive::GetPluginVersion() { return 1; }
442
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)443 size_t ObjectContainerBSDArchive::GetModuleSpecifications(
444 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
445 lldb::offset_t data_offset, lldb::offset_t file_offset,
446 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) {
447
448 // We have data, which means this is the first 512 bytes of the file Check to
449 // see if the magic bytes match and if they do, read the entire table of
450 // contents for the archive and cache it
451 DataExtractor data;
452 data.SetData(data_sp, data_offset, data_sp->GetByteSize());
453 if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data))
454 return 0;
455
456 const size_t initial_count = specs.GetSize();
457 llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file);
458 Archive::shared_ptr archive_sp(
459 Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset));
460 bool set_archive_arch = false;
461 if (!archive_sp) {
462 set_archive_arch = true;
463 data_sp =
464 FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset);
465 if (data_sp) {
466 data.SetData(data_sp, 0, data_sp->GetByteSize());
467 archive_sp = Archive::ParseAndCacheArchiveForFile(
468 file, ArchSpec(), file_mod_time, file_offset, data);
469 }
470 }
471
472 if (archive_sp) {
473 const size_t num_objects = archive_sp->GetNumObjects();
474 for (size_t idx = 0; idx < num_objects; ++idx) {
475 const Object *object = archive_sp->GetObjectAtIndex(idx);
476 if (object) {
477 const lldb::offset_t object_file_offset =
478 file_offset + object->file_offset;
479 if (object->file_offset < file_size && file_size > object_file_offset) {
480 if (ObjectFile::GetModuleSpecifications(
481 file, object_file_offset, file_size - object_file_offset,
482 specs)) {
483 ModuleSpec &spec =
484 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1);
485 llvm::sys::TimePoint<> object_mod_time(
486 std::chrono::seconds(object->modification_time));
487 spec.GetObjectName() = object->ar_name;
488 spec.SetObjectOffset(object_file_offset);
489 spec.SetObjectSize(file_size - object_file_offset);
490 spec.GetObjectModificationTime() = object_mod_time;
491 }
492 }
493 }
494 }
495 }
496 const size_t end_count = specs.GetSize();
497 size_t num_specs_added = end_count - initial_count;
498 if (set_archive_arch && num_specs_added > 0) {
499 // The archive was created but we didn't have an architecture so we need to
500 // set it
501 for (size_t i = initial_count; i < end_count; ++i) {
502 ModuleSpec module_spec;
503 if (specs.GetModuleSpecAtIndex(i, module_spec)) {
504 if (module_spec.GetArchitecture().IsValid()) {
505 archive_sp->SetArchitecture(module_spec.GetArchitecture());
506 break;
507 }
508 }
509 }
510 }
511 return num_specs_added;
512 }
513