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ObjectContainerBSDArchive.cpp
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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 
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"
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 
44 
46  : ar_name(), modification_time(0), uid(0), gid(0), mode(0), size(0),
47  file_offset(0), file_size(0) {}
48 
50  ar_name.Clear();
51  modification_time = 0;
52  uid = 0;
53  gid = 0;
54  mode = 0;
55  size = 0;
56  file_offset = 0;
57  file_size = 0;
58 }
59 
62  lldb::offset_t offset) {
63  size_t ar_name_len = 0;
64  std::string str;
65  char *err;
66 
67  // File header
68  //
69  // The common format is as follows.
70  //
71  // Offset Length Name Format
72  // 0 16 File name ASCII right padded with spaces (no spaces
73  // allowed in file name)
74  // 16 12 File mod Decimal as cstring right padded with
75  // spaces
76  // 28 6 Owner ID Decimal as cstring right padded with
77  // spaces
78  // 34 6 Group ID Decimal as cstring right padded with
79  // spaces
80  // 40 8 File mode Octal as cstring right padded with
81  // spaces
82  // 48 10 File byte size Decimal as cstring right padded with
83  // spaces
84  // 58 2 File magic 0x60 0x0A
85 
86  // Make sure there is enough data for the file header and bail if not
87  if (!data.ValidOffsetForDataOfSize(offset, 60))
88  return LLDB_INVALID_OFFSET;
89 
90  str.assign((const char *)data.GetData(&offset, 16), 16);
91  if (llvm::StringRef(str).startswith("#1/")) {
92  // If the name is longer than 16 bytes, or contains an embedded space then
93  // it will use this format where the length of the name is here and the
94  // name characters are after this header.
95  ar_name_len = strtoul(str.c_str() + 3, &err, 10);
96  } else {
97  // Strip off any trailing spaces.
98  const size_t last_pos = str.find_last_not_of(' ');
99  if (last_pos != std::string::npos) {
100  if (last_pos + 1 < 16)
101  str.erase(last_pos + 1);
102  }
103  ar_name.SetCString(str.c_str());
104  }
105 
106  str.assign((const char *)data.GetData(&offset, 12), 12);
107  modification_time = strtoul(str.c_str(), &err, 10);
108 
109  str.assign((const char *)data.GetData(&offset, 6), 6);
110  uid = strtoul(str.c_str(), &err, 10);
111 
112  str.assign((const char *)data.GetData(&offset, 6), 6);
113  gid = strtoul(str.c_str(), &err, 10);
114 
115  str.assign((const char *)data.GetData(&offset, 8), 8);
116  mode = strtoul(str.c_str(), &err, 8);
117 
118  str.assign((const char *)data.GetData(&offset, 10), 10);
119  size = strtoul(str.c_str(), &err, 10);
120 
121  str.assign((const char *)data.GetData(&offset, 2), 2);
122  if (str == ARFMAG) {
123  if (ar_name_len > 0) {
124  const void *ar_name_ptr = data.GetData(&offset, ar_name_len);
125  // Make sure there was enough data for the string value and bail if not
126  if (ar_name_ptr == nullptr)
127  return LLDB_INVALID_OFFSET;
128  str.assign((const char *)ar_name_ptr, ar_name_len);
129  ar_name.SetCString(str.c_str());
130  }
131  file_offset = offset;
132  file_size = size - ar_name_len;
133  return offset;
134  }
135  return LLDB_INVALID_OFFSET;
136 }
137 
139  const llvm::sys::TimePoint<> &time,
140  lldb::offset_t file_offset,
142  : m_arch(arch), m_modification_time(time), m_file_offset(file_offset),
143  m_objects(), m_data(data) {}
144 
146 
148  DataExtractor &data = m_data;
149  std::string str;
150  lldb::offset_t offset = 0;
151  str.assign((const char *)data.GetData(&offset, SARMAG), SARMAG);
152  if (str == ARMAG) {
153  Object obj;
154  do {
155  offset = obj.Extract(data, offset);
156  if (offset == LLDB_INVALID_OFFSET)
157  break;
158  size_t obj_idx = m_objects.size();
159  m_objects.push_back(obj);
160  // Insert all of the C strings out of order for now...
162  offset += obj.file_size;
163  obj.Clear();
164  } while (data.ValidOffset(offset));
165 
166  // Now sort all of the object name pointers
168  }
169  return m_objects.size();
170 }
171 
174  ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) {
175  const ObjectNameToIndexMap::Entry *match =
177  if (!match)
178  return nullptr;
179  if (object_mod_time == llvm::sys::TimePoint<>())
180  return &m_objects[match->value];
181 
182  const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time);
183  if (m_objects[match->value].modification_time == object_modification_date)
184  return &m_objects[match->value];
185 
186  const ObjectNameToIndexMap::Entry *next_match =
188  while (next_match) {
189  if (m_objects[next_match->value].modification_time ==
190  object_modification_date)
191  return &m_objects[next_match->value];
192  next_match = m_object_name_to_index_map.FindNextValueForName(next_match);
193  }
194 
195  return nullptr;
196 }
197 
200  const FileSpec &file, const ArchSpec &arch,
201  const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) {
202  std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex());
203  shared_ptr archive_sp;
204  Archive::Map &archive_map = Archive::GetArchiveCache();
205  Archive::Map::iterator pos = archive_map.find(file);
206  // Don't cache a value for "archive_map.end()" below since we might delete an
207  // archive entry...
208  while (pos != archive_map.end() && pos->first == file) {
209  bool match = true;
210  if (arch.IsValid() &&
211  !pos->second->GetArchitecture().IsCompatibleMatch(arch))
212  match = false;
213  else if (file_offset != LLDB_INVALID_OFFSET &&
214  pos->second->GetFileOffset() != file_offset)
215  match = false;
216  if (match) {
217  if (pos->second->GetModificationTime() == time) {
218  return pos->second;
219  } else {
220  // We have a file at the same path with the same architecture whose
221  // modification time doesn't match. It doesn't make sense for us to
222  // continue to use this BSD archive since we cache only the object info
223  // which consists of file time info and also the file offset and file
224  // size of any contained objects. Since this information is now out of
225  // date, we won't get the correct information if we go and extract the
226  // file data, so we should remove the old and outdated entry.
227  archive_map.erase(pos);
228  pos = archive_map.find(file);
229  continue; // Continue to next iteration so we don't increment pos
230  // below...
231  }
232  }
233  ++pos;
234  }
235  return archive_sp;
236 }
237 
240  const FileSpec &file, const ArchSpec &arch,
241  const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset,
242  DataExtractor &data) {
243  shared_ptr archive_sp(new Archive(arch, time, file_offset, data));
244  if (archive_sp) {
245  const size_t num_objects = archive_sp->ParseObjects();
246  if (num_objects > 0) {
247  std::lock_guard<std::recursive_mutex> guard(
249  Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp));
250  } else {
251  archive_sp.reset();
252  }
253  }
254  return archive_sp;
255 }
256 
259  static Archive::Map g_archive_map;
260  return g_archive_map;
261 }
262 
263 std::recursive_mutex &
265  static std::recursive_mutex g_archive_map_mutex;
266  return g_archive_map_mutex;
267 }
268 
270  PluginManager::RegisterPlugin(GetPluginNameStatic(),
273 }
274 
276  PluginManager::UnregisterPlugin(CreateInstance);
277 }
278 
280  static ConstString g_name("bsd-archive");
281  return g_name;
282 }
283 
285  return "BSD Archive object container reader.";
286 }
287 
289  const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
290  lldb::offset_t data_offset, const FileSpec *file,
291  lldb::offset_t file_offset, lldb::offset_t length) {
292  ConstString object_name(module_sp->GetObjectName());
293  if (!object_name)
294  return nullptr;
295 
296  if (data_sp) {
297  // We have data, which means this is the first 512 bytes of the file Check
298  // to see if the magic bytes match and if they do, read the entire table of
299  // contents for the archive and cache it
300  DataExtractor data;
301  data.SetData(data_sp, data_offset, length);
302  if (file && data_sp && ObjectContainerBSDArchive::MagicBytesMatch(data)) {
303  static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
304  Timer scoped_timer(
305  func_cat,
306  "ObjectContainerBSDArchive::CreateInstance (module = %s, file = "
307  "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
308  module_sp->GetFileSpec().GetPath().c_str(),
309  static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
310  static_cast<uint64_t>(length));
311 
312  // Map the entire .a file to be sure that we don't lose any data if the
313  // file gets updated by a new build while this .a file is being used for
314  // debugging
315  DataBufferSP archive_data_sp =
316  FileSystem::Instance().CreateDataBuffer(*file, length, file_offset);
317  if (!archive_data_sp)
318  return nullptr;
319 
320  lldb::offset_t archive_data_offset = 0;
321 
323  *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
324  file_offset));
325  std::unique_ptr<ObjectContainerBSDArchive> container_up(
326  new ObjectContainerBSDArchive(module_sp, archive_data_sp,
327  archive_data_offset, file, file_offset,
328  length));
329 
330  if (container_up) {
331  if (archive_sp) {
332  // We already have this archive in our cache, use it
333  container_up->SetArchive(archive_sp);
334  return container_up.release();
335  } else if (container_up->ParseHeader())
336  return container_up.release();
337  }
338  }
339  } else {
340  // No data, just check for a cached archive
342  *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
343  file_offset));
344  if (archive_sp) {
345  std::unique_ptr<ObjectContainerBSDArchive> container_up(
346  new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file,
347  file_offset, length));
348 
349  if (container_up) {
350  // We already have this archive in our cache, use it
351  container_up->SetArchive(archive_sp);
352  return container_up.release();
353  }
354  }
355  }
356  return nullptr;
357 }
358 
360  uint32_t offset = 0;
361  const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr));
362  if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) {
363  armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
364  if (strncmp(armag, ARFMAG, 2) == 0)
365  return true;
366  }
367  return false;
368 }
369 
371  const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
372  lldb::offset_t data_offset, const lldb_private::FileSpec *file,
373  lldb::offset_t file_offset, lldb::offset_t size)
374  : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset),
375  m_archive_sp() {}
377  m_archive_sp = archive_sp;
378 }
379 
381 
383  if (m_archive_sp.get() == nullptr) {
384  if (m_data.GetByteSize() > 0) {
385  ModuleSP module_sp(GetModule());
386  if (module_sp) {
388  m_file, module_sp->GetArchitecture(),
389  module_sp->GetModificationTime(), m_offset, m_data);
390  }
391  // Clear the m_data that contains the entire archive data and let our
392  // m_archive_sp hold onto the data.
393  m_data.Clear();
394  }
395  }
396  return m_archive_sp.get() != nullptr;
397 }
398 
400  s->Printf("%p: ", static_cast<const void *>(this));
401  s->Indent();
402  const size_t num_archs = GetNumArchitectures();
403  const size_t num_objects = GetNumObjects();
404  s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64
405  ", num_objects = %" PRIu64 "",
406  (uint64_t)num_archs, (uint64_t)num_objects);
407  uint32_t i;
408  ArchSpec arch;
409  s->IndentMore();
410  for (i = 0; i < num_archs; i++) {
411  s->Indent();
412  GetArchitectureAtIndex(i, arch);
413  s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName());
414  }
415  for (i = 0; i < num_objects; i++) {
416  s->Indent();
417  s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i));
418  }
419  s->IndentLess();
420  s->EOL();
421 }
422 
424  ModuleSP module_sp(GetModule());
425  if (module_sp) {
426  if (module_sp->GetObjectName() && m_archive_sp) {
427  Object *object = m_archive_sp->FindObject(
428  module_sp->GetObjectName(), module_sp->GetObjectModificationTime());
429  if (object) {
430  lldb::offset_t data_offset = object->file_offset;
431  return ObjectFile::FindPlugin(
432  module_sp, file, m_offset + object->file_offset, object->file_size,
433  m_archive_sp->GetData().GetSharedDataBuffer(), data_offset);
434  }
435  }
436  }
437  return ObjectFileSP();
438 }
439 
440 // PluginInterface protocol
442  return GetPluginNameStatic();
443 }
444 
446 
448  const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
449  lldb::offset_t data_offset, lldb::offset_t file_offset,
450  lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) {
451 
452  // We have data, which means this is the first 512 bytes of the file Check to
453  // see if the magic bytes match and if they do, read the entire table of
454  // contents for the archive and cache it
455  DataExtractor data;
456  data.SetData(data_sp, data_offset, data_sp->GetByteSize());
457  if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data))
458  return 0;
459 
460  const size_t initial_count = specs.GetSize();
461  llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file);
462  Archive::shared_ptr archive_sp(
463  Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset));
464  bool set_archive_arch = false;
465  if (!archive_sp) {
466  set_archive_arch = true;
467  data_sp =
468  FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset);
469  if (data_sp) {
470  data.SetData(data_sp, 0, data_sp->GetByteSize());
472  file, ArchSpec(), file_mod_time, file_offset, data);
473  }
474  }
475 
476  if (archive_sp) {
477  const size_t num_objects = archive_sp->GetNumObjects();
478  for (size_t idx = 0; idx < num_objects; ++idx) {
479  const Object *object = archive_sp->GetObjectAtIndex(idx);
480  if (object) {
481  const lldb::offset_t object_file_offset =
482  file_offset + object->file_offset;
483  if (object->file_offset < file_size && file_size > object_file_offset) {
484  if (ObjectFile::GetModuleSpecifications(
485  file, object_file_offset, file_size - object_file_offset,
486  specs)) {
487  ModuleSpec &spec =
488  specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1);
489  llvm::sys::TimePoint<> object_mod_time(
490  std::chrono::seconds(object->modification_time));
491  spec.GetObjectName() = object->ar_name;
492  spec.SetObjectOffset(object_file_offset);
493  spec.SetObjectSize(file_size - object_file_offset);
494  spec.GetObjectModificationTime() = object_mod_time;
495  }
496  }
497  }
498  }
499  }
500  const size_t end_count = specs.GetSize();
501  size_t num_specs_added = end_count - initial_count;
502  if (set_archive_arch && num_specs_added > 0) {
503  // The archive was created but we didn't have an architecture so we need to
504  // set it
505  for (size_t i = initial_count; i < end_count; ++i) {
506  ModuleSpec module_spec;
507  if (specs.GetModuleSpecAtIndex(i, module_spec)) {
508  if (module_spec.GetArchitecture().IsValid()) {
509  archive_sp->SetArchitecture(module_spec.GetArchitecture());
510  break;
511  }
512  }
513  }
514  }
515  return num_specs_added;
516 }
static lldb_private::ObjectContainer * CreateInstance(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp, lldb::offset_t data_offset, const lldb_private::FileSpec *file, lldb::offset_t offset, lldb::offset_t length)
void SetObjectOffset(uint64_t object_offset)
Definition: ModuleSpec.h:131
static Archive::shared_ptr FindCachedArchive(const lldb_private::FileSpec &file, const lldb_private::ArchSpec &arch, const llvm::sys::TimePoint<> &mod_time, lldb::offset_t file_offset)
An data extractor class.
Definition: DataExtractor.h:46
void IndentMore(unsigned amount=2)
Increment the current indentation level.
Definition: Stream.cpp:167
A class that represents a running process on the host machine.
static lldb_private::ConstString GetPluginNameStatic()
static bool MagicBytesMatch(const lldb_private::DataExtractor &data)
const void * GetData(lldb::offset_t *offset_ptr, lldb::offset_t length) const
Extract length bytes from *offset_ptr.
A stream class that can stream formatted output to a file.
Definition: Stream.h:28
ObjectContainerBSDArchive(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp, lldb::offset_t data_offset, const lldb_private::FileSpec *file, lldb::offset_t offset, lldb::offset_t length)
void IndentLess(unsigned amount=2)
Decrement the current indentation level.
Definition: Stream.cpp:170
const Entry * FindFirstValueForName(ConstString unique_cstr) const
A file utility class.
Definition: FileSpec.h:56
An architecture specification class.
Definition: ArchSpec.h:33
A timer class that simplifies common timing metrics.
Definition: Timer.h:23
lldb::addr_t m_offset
The offset in bytes into the file, or the address in memory.
A plug-in interface definition class for object containers.
lldb::offset_t file_offset
File offset in bytes from the beginning of the file of the object data.
size_t GetNumObjects() const override
Get the number of objects within this object file (archives).
virtual const char * GetObjectNameAtIndex(uint32_t object_idx) const
virtual bool GetArchitectureAtIndex(uint32_t idx, ArchSpec &arch) const
Gets the architecture given an index.
Object * FindObject(lldb_private::ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time)
bool IsValid() const
Tests if this ArchSpec is valid.
Definition: ArchSpec.h:332
bool ParseHeader() override
Attempts to parse the object header.
lldb::ModuleSP GetModule() const
Get const accessor for the module pointer.
Definition: ModuleChild.cpp:24
#define LLDB_INVALID_OFFSET
Definition: lldb-defines.h:96
static const char * GetPluginDescriptionStatic()
uint32_t modification_time
Object modification time in the archive.
const char * GetArchitectureName() const
Returns a static string representing the current architecture.
Definition: ArchSpec.cpp:585
void SetArchive(Archive::shared_ptr &archive_sp)
#define LLDB_PLUGIN_DEFINE(PluginName)
Definition: PluginManager.h:31
size_t Indent(llvm::StringRef s="")
Indent the current line in the stream.
Definition: Stream.cpp:129
lldb_private::ConstString ar_name
Object name in the archive.
lldb::offset_t SetData(const void *bytes, lldb::offset_t length, lldb::ByteOrder byte_order)
Set data with a buffer that is caller owned.
uint64_t offset_t
Definition: lldb-types.h:87
void Clear()
Clears the object state.
void Dump(lldb_private::Stream *s) const override
Dump a description of this object to a Stream.
size_t EOL()
Output and End of Line character to the stream.
Definition: Stream.cpp:127
lldb::offset_t Extract(const lldb_private::DataExtractor &data, lldb::offset_t offset)
void Append(ConstString unique_cstr, const T &value)
#define offsetof(t, d)
DataExtractor m_data
The data for this object file so things can be parsed lazily.
bool ValidOffsetForDataOfSize(lldb::offset_t offset, lldb::offset_t length) const
Test the availability of length bytes of data from offset.
size_t Printf(const char *format,...) __attribute__((format(printf
Output printf formatted output to the stream.
Definition: Stream.cpp:106
static std::recursive_mutex & GetArchiveCacheMutex()
bool ValidOffset(lldb::offset_t offset) const
Test the validity of offset.
uint64_t GetByteSize() const
Get the number of bytes contained in this object.
ArchSpec & GetArchitecture()
Definition: ModuleSpec.h:111
static Archive::shared_ptr ParseAndCacheArchiveForFile(const lldb_private::FileSpec &file, const lldb_private::ArchSpec &arch, const llvm::sys::TimePoint<> &mod_time, lldb::offset_t file_offset, lldb_private::DataExtractor &data)
lldb::ObjectFileSP GetObjectFile(const lldb_private::FileSpec *file) override
Selects an architecture in an object file.
virtual size_t GetNumArchitectures() const
Get the number of architectures in this object file.
lldb::offset_t file_size
Length of the object data.
A uniqued constant string class.
Definition: ConstString.h:40
static size_t GetModuleSpecifications(const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp, lldb::offset_t data_offset, lldb::offset_t file_offset, lldb::offset_t length, lldb_private::ModuleSpecList &specs)
lldb_private::DataExtractor m_data
The data for this object container so we don&#39;t lose data if the .a files gets modified.
Definition: SBAddress.h:15
FileSpec m_file
The file that represents this container objects (which can be different from the module&#39;s file)...
lldb_private::ConstString GetPluginName() override
bool GetModuleSpecAtIndex(size_t i, ModuleSpec &module_spec) const
Definition: ModuleSpec.h:342
std::multimap< lldb_private::FileSpec, shared_ptr > Map
ModuleSpec & GetModuleSpecRefAtIndex(size_t i)
Definition: ModuleSpec.h:340
Archive(const lldb_private::ArchSpec &arch, const llvm::sys::TimePoint<> &mod_time, lldb::offset_t file_offset, lldb_private::DataExtractor &data)
void SetObjectSize(uint64_t object_size)
Definition: ModuleSpec.h:137
const Entry * FindNextValueForName(const Entry *entry_ptr) const
const uint8_t * PeekData(lldb::offset_t offset, lldb::offset_t length) const
Peek at a bytes at offset.
ConstString & GetObjectName()
Definition: ModuleSpec.h:125
llvm::sys::TimePoint & GetObjectModificationTime()
Definition: ModuleSpec.h:139