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ObjectContainerBSDArchive.cpp
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1 //===-- ObjectContainerBSDArchive.cpp ---------------------------*- C++ -*-===//
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  : ar_name(), ar_date(0), ar_uid(0), ar_gid(0), ar_mode(0), ar_size(0),
45  ar_file_offset(0), ar_file_size(0) {}
46 
48  ar_name.Clear();
49  ar_date = 0;
50  ar_uid = 0;
51  ar_gid = 0;
52  ar_mode = 0;
53  ar_size = 0;
54  ar_file_offset = 0;
55  ar_file_size = 0;
56 }
57 
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 (str.find("#1/") == 0) {
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  ar_date = strtoul(str.c_str(), &err, 10);
106 
107  str.assign((const char *)data.GetData(&offset, 6), 6);
108  ar_uid = strtoul(str.c_str(), &err, 10);
109 
110  str.assign((const char *)data.GetData(&offset, 6), 6);
111  ar_gid = strtoul(str.c_str(), &err, 10);
112 
113  str.assign((const char *)data.GetData(&offset, 8), 8);
114  ar_mode = strtoul(str.c_str(), &err, 8);
115 
116  str.assign((const char *)data.GetData(&offset, 10), 10);
117  ar_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 == NULL)
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  ar_file_offset = offset;
130  ar_file_size = ar_size - ar_name_len;
131  return offset;
132  }
133  return LLDB_INVALID_OFFSET;
134 }
135 
137  const llvm::sys::TimePoint<> &time,
138  lldb::offset_t file_offset,
140  : m_arch(arch), m_time(time), m_file_offset(file_offset), m_objects(),
141  m_data(data) {}
142 
144 
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...
160  offset += obj.ar_file_size;
161  obj.Clear();
162  } while (data.ValidOffset(offset));
163 
164  // Now sort all of the object name pointers
166  }
167  return m_objects.size();
168 }
169 
172  ConstString object_name,
173  const llvm::sys::TimePoint<> &object_mod_time) {
174  const ObjectNameToIndexMap::Entry *match =
176  if (match) {
177  if (object_mod_time != llvm::sys::TimePoint<>()) {
178  const uint64_t object_date = llvm::sys::toTimeT(object_mod_time);
179  if (m_objects[match->value].ar_date == object_date)
180  return &m_objects[match->value];
181  const ObjectNameToIndexMap::Entry *next_match =
183  while (next_match) {
184  if (m_objects[next_match->value].ar_date == object_date)
185  return &m_objects[next_match->value];
186  next_match =
188  }
189  } else {
190  return &m_objects[match->value];
191  }
192  }
193  return NULL;
194 }
195 
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 
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(
247  Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp));
248  } else {
249  archive_sp.reset();
250  }
251  }
252  return archive_sp;
253 }
254 
257  static Archive::Map g_archive_map;
258  return g_archive_map;
259 }
260 
261 std::recursive_mutex &
263  static std::recursive_mutex g_archive_map_mutex;
264  return g_archive_map_mutex;
265 }
266 
268  PluginManager::RegisterPlugin(GetPluginNameStatic(),
271 }
272 
274  PluginManager::UnregisterPlugin(CreateInstance);
275 }
276 
278  static ConstString g_name("bsd-archive");
279  return g_name;
280 }
281 
283  return "BSD Archive object container reader.";
284 }
285 
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  static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
302  Timer scoped_timer(
303  func_cat,
304  "ObjectContainerBSDArchive::CreateInstance (module = %s, file = "
305  "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
306  module_sp->GetFileSpec().GetPath().c_str(),
307  static_cast<const void *>(file), static_cast<uint64_t>(file_offset),
308  static_cast<uint64_t>(length));
309 
310  // Map the entire .a file to be sure that we don't lose any data if the
311  // file gets updated by a new build while this .a file is being used for
312  // debugging
313  DataBufferSP archive_data_sp =
314  FileSystem::Instance().CreateDataBuffer(*file, length, file_offset);
315  if (!archive_data_sp)
316  return nullptr;
317 
318  lldb::offset_t archive_data_offset = 0;
319 
321  *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
322  file_offset));
323  std::unique_ptr<ObjectContainerBSDArchive> container_up(
324  new ObjectContainerBSDArchive(module_sp, archive_data_sp,
325  archive_data_offset, file, file_offset,
326  length));
327 
328  if (container_up) {
329  if (archive_sp) {
330  // We already have this archive in our cache, use it
331  container_up->SetArchive(archive_sp);
332  return container_up.release();
333  } else if (container_up->ParseHeader())
334  return container_up.release();
335  }
336  }
337  } else {
338  // No data, just check for a cached archive
340  *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(),
341  file_offset));
342  if (archive_sp) {
343  std::unique_ptr<ObjectContainerBSDArchive> container_up(
344  new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file,
345  file_offset, length));
346 
347  if (container_up) {
348  // We already have this archive in our cache, use it
349  container_up->SetArchive(archive_sp);
350  return container_up.release();
351  }
352  }
353  }
354  return NULL;
355 }
356 
358  uint32_t offset = 0;
359  const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr));
360  if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) {
361  armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
362  if (strncmp(armag, ARFMAG, 2) == 0)
363  return true;
364  }
365  return false;
366 }
367 
369  const lldb::ModuleSP &module_sp, DataBufferSP &data_sp,
370  lldb::offset_t data_offset, const lldb_private::FileSpec *file,
371  lldb::offset_t file_offset, lldb::offset_t size)
372  : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset),
373  m_archive_sp() {}
375  m_archive_sp = archive_sp;
376 }
377 
379 
381  if (m_archive_sp.get() == NULL) {
382  if (m_data.GetByteSize() > 0) {
383  ModuleSP module_sp(GetModule());
384  if (module_sp) {
386  m_file, module_sp->GetArchitecture(),
387  module_sp->GetModificationTime(), m_offset, m_data);
388  }
389  // Clear the m_data that contains the entire archive data and let our
390  // m_archive_sp hold onto the data.
391  m_data.Clear();
392  }
393  }
394  return m_archive_sp.get() != NULL;
395 }
396 
398  s->Printf("%p: ", static_cast<const void *>(this));
399  s->Indent();
400  const size_t num_archs = GetNumArchitectures();
401  const size_t num_objects = GetNumObjects();
402  s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64
403  ", num_objects = %" PRIu64 "",
404  (uint64_t)num_archs, (uint64_t)num_objects);
405  uint32_t i;
406  ArchSpec arch;
407  s->IndentMore();
408  for (i = 0; i < num_archs; i++) {
409  s->Indent();
410  GetArchitectureAtIndex(i, arch);
411  s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName());
412  }
413  for (i = 0; i < num_objects; i++) {
414  s->Indent();
415  s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i));
416  }
417  s->IndentLess();
418  s->EOL();
419 }
420 
422  ModuleSP module_sp(GetModule());
423  if (module_sp) {
424  if (module_sp->GetObjectName() && m_archive_sp) {
425  Object *object = m_archive_sp->FindObject(
426  module_sp->GetObjectName(), module_sp->GetObjectModificationTime());
427  if (object) {
428  lldb::offset_t data_offset = object->ar_file_offset;
429  return ObjectFile::FindPlugin(
430  module_sp, file, m_offset + object->ar_file_offset,
431  object->ar_file_size, m_archive_sp->GetData().GetSharedDataBuffer(),
432  data_offset);
433  }
434  }
435  }
436  return ObjectFileSP();
437 }
438 
439 // PluginInterface protocol
441  return GetPluginNameStatic();
442 }
443 
445 
447  const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
448  lldb::offset_t data_offset, lldb::offset_t file_offset,
449  lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) {
450 
451  // We have data, which means this is the first 512 bytes of the file Check to
452  // see if the magic bytes match and if they do, read the entire table of
453  // contents for the archive and cache it
454  DataExtractor data;
455  data.SetData(data_sp, data_offset, data_sp->GetByteSize());
456  if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data))
457  return 0;
458 
459  const size_t initial_count = specs.GetSize();
460  llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file);
461  Archive::shared_ptr archive_sp(
462  Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset));
463  bool set_archive_arch = false;
464  if (!archive_sp) {
465  set_archive_arch = true;
466  data_sp =
467  FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset);
468  if (data_sp) {
469  data.SetData(data_sp, 0, data_sp->GetByteSize());
471  file, ArchSpec(), file_mod_time, file_offset, data);
472  }
473  }
474 
475  if (archive_sp) {
476  const size_t num_objects = archive_sp->GetNumObjects();
477  for (size_t idx = 0; idx < num_objects; ++idx) {
478  const Object *object = archive_sp->GetObjectAtIndex(idx);
479  if (object) {
480  const lldb::offset_t object_file_offset =
481  file_offset + object->ar_file_offset;
482  if (object->ar_file_offset < file_size &&
483  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->ar_date));
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:47
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
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)
const Entry * FindFirstValueForName(ConstString unique_cstr) const
A file utility class.
Definition: FileSpec.h:55
An architecture specification class.
Definition: ArchSpec.h:32
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.
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:329
bool ParseHeader() override
Attempts to parse the object header.
lldb::ModuleSP GetModule() const
Get const accessor for the module pointer.
Definition: ModuleChild.cpp:27
#define LLDB_INVALID_OFFSET
Definition: lldb-defines.h:96
static const char * GetPluginDescriptionStatic()
const char * GetArchitectureName() const
Returns a static string representing the current architecture.
Definition: ArchSpec.cpp:591
void SetArchive(Archive::shared_ptr &archive_sp)
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)
void IndentLess(int amount=2)
Decrement the current indentation level.
Definition: Stream.cpp:221
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.
A uniqued constant string class.
Definition: ConstString.h:38
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
size_t Indent(const char *s=nullptr)
Indent the current line in the stream.
Definition: Stream.cpp:131
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:348
void IndentMore(int amount=2)
Increment the current indentation level.
Definition: Stream.cpp:218
std::multimap< lldb_private::FileSpec, shared_ptr > Map
ModuleSpec & GetModuleSpecRefAtIndex(size_t i)
Definition: ModuleSpec.h:346
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
void Clear()
Clear this object&#39;s state.
Definition: ConstString.h:263
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
void SetCString(const char *cstr)
Set the C string value.