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(_AIX)
12// Defines from ar, missing on Windows
13#define SARMAG 8
14#define ARFMAG "`\n"
15
16typedef 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
41using namespace lldb;
42using namespace lldb_private;
43
44using namespace llvm::object;
45
46LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive)
47
48ObjectContainerBSDArchive::Object::Object() : ar_name() {}
49
50void ObjectContainerBSDArchive::Object::Clear() {
51 ar_name.Clear();
52 modification_time = 0;
53 size = 0;
54 file_offset = 0;
55 file_size = 0;
56}
57
58void ObjectContainerBSDArchive::Object::Dump() const {
59 printf(format: "name = \"%s\"\n", ar_name.GetCString());
60 printf(format: "mtime = 0x%8.8" PRIx32 "\n", modification_time);
61 printf(format: "size = 0x%8.8" PRIx32 " (%" PRIu32 ")\n", size, size);
62 printf(format: "file_offset = 0x%16.16" PRIx64 " (%" PRIu64 ")\n", file_offset,
63 file_offset);
64 printf(format: "file_size = 0x%16.16" PRIx64 " (%" PRIu64 ")\n\n", file_size,
65 file_size);
66}
67
68ObjectContainerBSDArchive::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
76Log *l = GetLog(mask: LLDBLog::Object);
77ObjectContainerBSDArchive::Archive::~Archive() = default;
78
79size_t ObjectContainerBSDArchive::Archive::ParseObjects() {
80 DataExtractor &data = m_data;
81
82 std::unique_ptr<llvm::MemoryBuffer> mem_buffer =
83 llvm::MemoryBuffer::getMemBuffer(
84 InputData: llvm::StringRef((const char *)data.GetDataStart(),
85 data.GetByteSize()),
86 BufferName: llvm::StringRef(),
87 /*RequiresNullTerminator=*/false);
88
89 auto exp_ar = llvm::object::Archive::create(Source: 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(Err&: 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 d: std::chrono::time_point_cast<std::chrono::seconds>(
114 t: exp_mtime.get())
115 .time_since_epoch())
116 .count();
117 } else {
118 LLDB_LOG_ERROR(l, exp_mtime.takeError(),
119 "failed to get archive object time: {0}");
120 continue;
121 }
122
123 auto exp_size = child.getRawSize();
124 if (exp_size) {
125 obj.size = exp_size.get();
126 } else {
127 LLDB_LOG_ERROR(l, exp_size.takeError(),
128 "failed to get archive object size: {0}");
129 continue;
130 }
131
132 obj.file_offset = child.getDataOffset();
133
134 auto exp_file_size = child.getSize();
135 if (exp_file_size) {
136 obj.file_size = exp_file_size.get();
137 } else {
138 LLDB_LOG_ERROR(l, exp_file_size.takeError(),
139 "failed to get archive object file size: {0}");
140 continue;
141 }
142 m_object_name_to_index_map.Append(unique_cstr: obj.ar_name, value: m_objects.size());
143 m_objects.push_back(x: obj);
144 }
145 if (iter_err) {
146 LLDB_LOG_ERROR(l, std::move(iter_err),
147 "failed to iterate over archive objects: {0}");
148 }
149 // Now sort all of the object name pointers
150 m_object_name_to_index_map.Sort();
151 return m_objects.size();
152}
153
154ObjectContainerBSDArchive::Object *
155ObjectContainerBSDArchive::Archive::FindObject(
156 ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) {
157 const ObjectNameToIndexMap::Entry *match =
158 m_object_name_to_index_map.FindFirstValueForName(unique_cstr: object_name);
159 if (!match)
160 return nullptr;
161 if (object_mod_time == llvm::sys::TimePoint<>())
162 return &m_objects[match->value];
163
164 const uint64_t object_modification_date = llvm::sys::toTimeT(TP: object_mod_time);
165 if (m_objects[match->value].modification_time == object_modification_date)
166 return &m_objects[match->value];
167
168 const ObjectNameToIndexMap::Entry *next_match =
169 m_object_name_to_index_map.FindNextValueForName(entry_ptr: match);
170 while (next_match) {
171 if (m_objects[next_match->value].modification_time ==
172 object_modification_date)
173 return &m_objects[next_match->value];
174 next_match = m_object_name_to_index_map.FindNextValueForName(entry_ptr: next_match);
175 }
176
177 return nullptr;
178}
179
180ObjectContainerBSDArchive::Archive::shared_ptr
181ObjectContainerBSDArchive::Archive::FindCachedArchive(
182 const FileSpec &file, const ArchSpec &arch,
183 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) {
184 std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex());
185 shared_ptr archive_sp;
186 Archive::Map &archive_map = Archive::GetArchiveCache();
187 Archive::Map::iterator pos = archive_map.find(x: file);
188 // Don't cache a value for "archive_map.end()" below since we might delete an
189 // archive entry...
190 while (pos != archive_map.end() && pos->first == file) {
191 bool match = true;
192 if (arch.IsValid() &&
193 !pos->second->GetArchitecture().IsCompatibleMatch(rhs: arch))
194 match = false;
195 else if (file_offset != LLDB_INVALID_OFFSET &&
196 pos->second->GetFileOffset() != file_offset)
197 match = false;
198 if (match) {
199 if (pos->second->GetModificationTime() == time) {
200 return pos->second;
201 } else {
202 // We have a file at the same path with the same architecture whose
203 // modification time doesn't match. It doesn't make sense for us to
204 // continue to use this BSD archive since we cache only the object info
205 // which consists of file time info and also the file offset and file
206 // size of any contained objects. Since this information is now out of
207 // date, we won't get the correct information if we go and extract the
208 // file data, so we should remove the old and outdated entry.
209 archive_map.erase(position: pos);
210 pos = archive_map.find(x: file);
211 continue; // Continue to next iteration so we don't increment pos
212 // below...
213 }
214 }
215 ++pos;
216 }
217 return archive_sp;
218}
219
220ObjectContainerBSDArchive::Archive::shared_ptr
221ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile(
222 const FileSpec &file, const ArchSpec &arch,
223 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset,
224 DataExtractor &data, ArchiveType archive_type) {
225 shared_ptr archive_sp(
226 new Archive(arch, time, file_offset, data, archive_type));
227 if (archive_sp) {
228 const size_t num_objects = archive_sp->ParseObjects();
229 if (num_objects > 0) {
230 std::lock_guard<std::recursive_mutex> guard(
231 Archive::GetArchiveCacheMutex());
232 Archive::GetArchiveCache().insert(x: std::make_pair(x: file, y&: archive_sp));
233 } else {
234 archive_sp.reset();
235 }
236 }
237 return archive_sp;
238}
239
240ObjectContainerBSDArchive::Archive::Map &
241ObjectContainerBSDArchive::Archive::GetArchiveCache() {
242 static Archive::Map g_archive_map;
243 return g_archive_map;
244}
245
246std::recursive_mutex &
247ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() {
248 static std::recursive_mutex g_archive_map_mutex;
249 return g_archive_map_mutex;
250}
251
252void ObjectContainerBSDArchive::Initialize() {
253 PluginManager::RegisterPlugin(name: GetPluginNameStatic(),
254 description: GetPluginDescriptionStatic(), create_callback: CreateInstance,
255 get_module_specifications: GetModuleSpecifications);
256}
257
258void ObjectContainerBSDArchive::Terminate() {
259 PluginManager::UnregisterPlugin(create_callback: CreateInstance);
260}
261
262ObjectContainer *ObjectContainerBSDArchive::CreateInstance(
263 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
264 lldb::offset_t data_offset, const FileSpec *file,
265 lldb::offset_t file_offset, lldb::offset_t length) {
266 ConstString object_name(module_sp->GetObjectName());
267 if (!object_name)
268 return nullptr;
269
270 if (data_sp) {
271 // We have data, which means this is the first 512 bytes of the file Check
272 // to see if the magic bytes match and if they do, read the entire table of
273 // contents for the archive and cache it
274 DataExtractor data;
275 data.SetData(data_sp, offset: data_offset, length);
276 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data);
277 if (file && data_sp && archive_type != ArchiveType::Invalid) {
278 LLDB_SCOPED_TIMERF(
279 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = "
280 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
281 module_sp->GetFileSpec().GetPath().c_str(),
282 static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
283 static_cast<uint64_t>(length));
284
285 // Map the entire .a file to be sure that we don't lose any data if the
286 // file gets updated by a new build while this .a file is being used for
287 // debugging
288 DataBufferSP archive_data_sp =
289 FileSystem::Instance().CreateDataBuffer(file_spec: *file, size: length, offset: file_offset);
290 if (!archive_data_sp)
291 return nullptr;
292
293 lldb::offset_t archive_data_offset = 0;
294
295 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
296 file: *file, arch: module_sp->GetArchitecture(), time: module_sp->GetModificationTime(),
297 file_offset));
298 std::unique_ptr<ObjectContainerBSDArchive> container_up(
299 new ObjectContainerBSDArchive(module_sp, archive_data_sp,
300 archive_data_offset, file, file_offset,
301 length, archive_type));
302
303 if (container_up) {
304 if (archive_sp) {
305 // We already have this archive in our cache, use it
306 container_up->SetArchive(archive_sp);
307 return container_up.release();
308 } else if (container_up->ParseHeader())
309 return container_up.release();
310 }
311 }
312 } else {
313 // No data, just check for a cached archive
314 Archive::shared_ptr archive_sp(Archive::FindCachedArchive(
315 file: *file, arch: module_sp->GetArchitecture(), time: module_sp->GetModificationTime(),
316 file_offset));
317 if (archive_sp) {
318 std::unique_ptr<ObjectContainerBSDArchive> container_up(
319 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file,
320 file_offset, length,
321 archive_sp->GetArchiveType()));
322
323 if (container_up) {
324 // We already have this archive in our cache, use it
325 container_up->SetArchive(archive_sp);
326 return container_up.release();
327 }
328 }
329 }
330 return nullptr;
331}
332
333ArchiveType
334ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) {
335 uint32_t offset = 0;
336 const char *armag =
337 (const char *)data.PeekData(offset, length: sizeof(ar_hdr) + SARMAG);
338 if (armag == nullptr)
339 return ArchiveType::Invalid;
340 ArchiveType result = ArchiveType::Invalid;
341 if (strncmp(s1: armag, s2: ArchiveMagic, SARMAG) == 0)
342 result = ArchiveType::Archive;
343 else if (strncmp(s1: armag, s2: ThinArchiveMagic, SARMAG) == 0)
344 result = ArchiveType::ThinArchive;
345 else
346 return ArchiveType::Invalid;
347
348 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
349 if (strncmp(s1: armag, ARFMAG, n: 2) == 0)
350 return result;
351 return ArchiveType::Invalid;
352}
353
354ObjectContainerBSDArchive::ObjectContainerBSDArchive(
355 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
356 lldb::offset_t data_offset, const lldb_private::FileSpec *file,
357 lldb::offset_t file_offset, lldb::offset_t size, ArchiveType archive_type)
358 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset),
359 m_archive_sp() {
360 m_archive_type = archive_type;
361}
362
363void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) {
364 m_archive_sp = archive_sp;
365}
366
367ObjectContainerBSDArchive::~ObjectContainerBSDArchive() = default;
368
369bool ObjectContainerBSDArchive::ParseHeader() {
370 if (m_archive_sp.get() == nullptr) {
371 if (m_data.GetByteSize() > 0) {
372 ModuleSP module_sp(GetModule());
373 if (module_sp) {
374 m_archive_sp = Archive::ParseAndCacheArchiveForFile(
375 file: m_file, arch: module_sp->GetArchitecture(),
376 time: module_sp->GetModificationTime(), file_offset: m_offset, data&: m_data, archive_type: m_archive_type);
377 }
378 // Clear the m_data that contains the entire archive data and let our
379 // m_archive_sp hold onto the data.
380 m_data.Clear();
381 }
382 }
383 return m_archive_sp.get() != nullptr;
384}
385
386FileSpec GetChildFileSpecificationsFromThin(llvm::StringRef childPath,
387 const FileSpec &parentFileSpec) {
388 llvm::SmallString<128> FullPath;
389 if (llvm::sys::path::is_absolute(path: childPath)) {
390 FullPath = childPath;
391 } else {
392 FullPath = parentFileSpec.GetDirectory().GetStringRef();
393 llvm::sys::path::append(path&: FullPath, a: childPath);
394 }
395 FileSpec child = FileSpec(FullPath.str(), llvm::sys::path::Style::posix);
396 return child;
397}
398
399ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) {
400 ModuleSP module_sp(GetModule());
401 if (module_sp) {
402 if (module_sp->GetObjectName() && m_archive_sp) {
403 Object *object = m_archive_sp->FindObject(
404 object_name: module_sp->GetObjectName(), object_mod_time: module_sp->GetObjectModificationTime());
405 if (object) {
406 if (m_archive_type == ArchiveType::ThinArchive) {
407 // Set file to child object file
408 FileSpec child = GetChildFileSpecificationsFromThin(
409 childPath: object->ar_name.GetStringRef(), parentFileSpec: m_file);
410 lldb::offset_t file_offset = 0;
411 lldb::offset_t file_size = object->size;
412 std::shared_ptr<DataBuffer> child_data_sp =
413 FileSystem::Instance().CreateDataBuffer(file_spec: child, size: file_size,
414 offset: file_offset);
415 if (!child_data_sp ||
416 child_data_sp->GetByteSize() != object->file_size)
417 return ObjectFileSP();
418 lldb::offset_t data_offset = 0;
419 return ObjectFile::FindPlugin(
420 module_sp, file_spec: &child, file_offset: m_offset + object->file_offset,
421 file_size: object->file_size, data_sp&: child_data_sp, data_offset);
422 }
423 lldb::offset_t data_offset = object->file_offset;
424 return ObjectFile::FindPlugin(
425 module_sp, file_spec: file, file_offset: m_offset + object->file_offset, file_size: object->file_size,
426 data_sp&: m_archive_sp->GetData().GetSharedDataBuffer(), data_offset);
427 }
428 }
429 }
430 return ObjectFileSP();
431}
432
433size_t ObjectContainerBSDArchive::GetModuleSpecifications(
434 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
435 lldb::offset_t data_offset, lldb::offset_t file_offset,
436 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) {
437
438 // We have data, which means this is the first 512 bytes of the file Check to
439 // see if the magic bytes match and if they do, read the entire table of
440 // contents for the archive and cache it
441 DataExtractor data;
442 data.SetData(data_sp, offset: data_offset, length: data_sp->GetByteSize());
443 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data);
444 if (!file || !data_sp || archive_type == ArchiveType::Invalid)
445 return 0;
446
447 const size_t initial_count = specs.GetSize();
448 llvm::sys::TimePoint<> file_mod_time =
449 FileSystem::Instance().GetModificationTime(file_spec: file);
450 Archive::shared_ptr archive_sp(
451 Archive::FindCachedArchive(file, arch: ArchSpec(), time: file_mod_time, file_offset));
452 bool set_archive_arch = false;
453 if (!archive_sp) {
454 set_archive_arch = true;
455 data_sp =
456 FileSystem::Instance().CreateDataBuffer(file_spec: file, size: file_size, offset: file_offset);
457 if (data_sp) {
458 data.SetData(data_sp, offset: 0, length: data_sp->GetByteSize());
459 archive_sp = Archive::ParseAndCacheArchiveForFile(
460 file, arch: ArchSpec(), time: file_mod_time, file_offset, data, archive_type);
461 }
462 }
463
464 if (archive_sp) {
465 const size_t num_objects = archive_sp->GetNumObjects();
466 for (size_t idx = 0; idx < num_objects; ++idx) {
467 const Object *object = archive_sp->GetObjectAtIndex(idx);
468 if (object) {
469 if (archive_sp->GetArchiveType() == ArchiveType::ThinArchive) {
470 if (object->ar_name.IsEmpty())
471 continue;
472 FileSpec child = GetChildFileSpecificationsFromThin(
473 childPath: object->ar_name.GetStringRef(), parentFileSpec: file);
474 if (ObjectFile::GetModuleSpecifications(file: child, file_offset: 0, file_size: object->file_size,
475 specs)) {
476 ModuleSpec &spec =
477 specs.GetModuleSpecRefAtIndex(i: specs.GetSize() - 1);
478 llvm::sys::TimePoint<> object_mod_time(
479 std::chrono::seconds(object->modification_time));
480 spec.GetObjectName() = object->ar_name;
481 spec.SetObjectOffset(0);
482 spec.SetObjectSize(object->file_size);
483 spec.GetObjectModificationTime() = object_mod_time;
484 }
485 continue;
486 }
487 const lldb::offset_t object_file_offset =
488 file_offset + object->file_offset;
489 if (object->file_offset < file_size && file_size > object_file_offset) {
490 if (ObjectFile::GetModuleSpecifications(
491 file, file_offset: object_file_offset, file_size: file_size - object_file_offset,
492 specs)) {
493 ModuleSpec &spec =
494 specs.GetModuleSpecRefAtIndex(i: specs.GetSize() - 1);
495 llvm::sys::TimePoint<> object_mod_time(
496 std::chrono::seconds(object->modification_time));
497 spec.GetObjectName() = object->ar_name;
498 spec.SetObjectOffset(object_file_offset);
499 spec.SetObjectSize(object->file_size);
500 spec.GetObjectModificationTime() = object_mod_time;
501 }
502 }
503 }
504 }
505 }
506 const size_t end_count = specs.GetSize();
507 size_t num_specs_added = end_count - initial_count;
508 if (set_archive_arch && num_specs_added > 0) {
509 // The archive was created but we didn't have an architecture so we need to
510 // set it
511 for (size_t i = initial_count; i < end_count; ++i) {
512 ModuleSpec module_spec;
513 if (specs.GetModuleSpecAtIndex(i, module_spec)) {
514 if (module_spec.GetArchitecture().IsValid()) {
515 archive_sp->SetArchitecture(module_spec.GetArchitecture());
516 break;
517 }
518 }
519 }
520 }
521 return num_specs_added;
522}
523

source code of lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp