1 //===-- ObjectContainerBSDArchive.cpp ---------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "ObjectContainerBSDArchive.h"
11 
12 #include <ar.h>
13 
14 #include "lldb/Core/Stream.h"
15 #include "lldb/Core/ArchSpec.h"
16 #include "lldb/Core/Module.h"
17 #include "lldb/Core/PluginManager.h"
18 #include "lldb/Core/Timer.h"
19 #include "lldb/Host/Mutex.h"
20 #include "lldb/Symbol/ObjectFile.h"
21 
22 using namespace lldb;
23 using namespace lldb_private;
24 
25 
26 
27 ObjectContainerBSDArchive::Object::Object() :
28     ar_name(),
29     ar_date(0),
30     ar_uid(0),
31     ar_gid(0),
32     ar_mode(0),
33     ar_size(0),
34     ar_file_offset(0),
35     ar_file_size(0)
36 {
37 }
38 
39 void
40 ObjectContainerBSDArchive::Object::Clear()
41 {
42     ar_name.Clear();
43     ar_date = 0;
44     ar_uid  = 0;
45     ar_gid  = 0;
46     ar_mode = 0;
47     ar_size = 0;
48     ar_file_offset = 0;
49     ar_file_size = 0;
50 }
51 
52 lldb::offset_t
53 ObjectContainerBSDArchive::Object::Extract (const DataExtractor& data, lldb::offset_t offset)
54 {
55     size_t ar_name_len = 0;
56     std::string str;
57     char *err;
58     str.assign ((const char *)data.GetData(&offset, 16),    16);
59     if (str.find("#1/") == 0)
60     {
61         // If the name is longer than 16 bytes, or contains an embedded space
62         // then it will use this format where the length of the name is
63         // here and the name characters are after this header.
64         ar_name_len = strtoul(str.c_str() + 3, &err, 10);
65     }
66     else
67     {
68         // Strip off any spaces (if the object file name contains spaces it
69         // will use the extended format above).
70         str.erase (str.find(' '));
71         ar_name.SetCString(str.c_str());
72     }
73 
74     str.assign ((const char *)data.GetData(&offset, 12),    12);
75     ar_date = strtoul(str.c_str(), &err, 10);
76 
77     str.assign ((const char *)data.GetData(&offset, 6), 6);
78     ar_uid  = strtoul(str.c_str(), &err, 10);
79 
80     str.assign ((const char *)data.GetData(&offset, 6), 6);
81     ar_gid  = strtoul(str.c_str(), &err, 10);
82 
83     str.assign ((const char *)data.GetData(&offset, 8), 8);
84     ar_mode = strtoul(str.c_str(), &err, 8);
85 
86     str.assign ((const char *)data.GetData(&offset, 10),    10);
87     ar_size = strtoul(str.c_str(), &err, 10);
88 
89     str.assign ((const char *)data.GetData(&offset, 2), 2);
90     if (str == ARFMAG)
91     {
92         if (ar_name_len > 0)
93         {
94             str.assign ((const char *)data.GetData(&offset, ar_name_len), ar_name_len);
95             ar_name.SetCString (str.c_str());
96         }
97         ar_file_offset = offset;
98         ar_file_size = ar_size - ar_name_len;
99         return offset;
100     }
101     return LLDB_INVALID_OFFSET;
102 }
103 
104 ObjectContainerBSDArchive::Archive::Archive
105 (
106     const lldb_private::ArchSpec &arch,
107     const lldb_private::TimeValue &time,
108     lldb_private::DataExtractor &data
109 ) :
110     m_arch (arch),
111     m_time (time),
112     m_objects(),
113     m_data (data)
114 {
115 }
116 
117 ObjectContainerBSDArchive::Archive::~Archive ()
118 {
119 }
120 
121 size_t
122 ObjectContainerBSDArchive::Archive::ParseObjects ()
123 {
124     DataExtractor &data = m_data;
125     std::string str;
126     lldb::offset_t offset = 0;
127     str.assign((const char *)data.GetData(&offset, SARMAG), SARMAG);
128     if (str == ARMAG)
129     {
130         Object obj;
131         do
132         {
133             offset = obj.Extract (data, offset);
134             if (offset == LLDB_INVALID_OFFSET)
135                 break;
136             size_t obj_idx = m_objects.size();
137             m_objects.push_back(obj);
138             // Insert all of the C strings out of order for now...
139             m_object_name_to_index_map.Append (obj.ar_name.GetCString(), obj_idx);
140             offset += obj.ar_file_size;
141             obj.Clear();
142         } while (data.ValidOffset(offset));
143 
144         // Now sort all of the object name pointers
145         m_object_name_to_index_map.Sort ();
146     }
147     return m_objects.size();
148 }
149 
150 ObjectContainerBSDArchive::Object *
151 ObjectContainerBSDArchive::Archive::FindObject (const ConstString &object_name)
152 {
153     const ObjectNameToIndexMap::Entry *match = m_object_name_to_index_map.FindFirstValueForName (object_name.GetCString());
154     if (match)
155         return &m_objects[match->value];
156     return NULL;
157 }
158 
159 
160 ObjectContainerBSDArchive::Archive::shared_ptr
161 ObjectContainerBSDArchive::Archive::FindCachedArchive (const FileSpec &file, const ArchSpec &arch, const TimeValue &time)
162 {
163     Mutex::Locker locker(Archive::GetArchiveCacheMutex ());
164     shared_ptr archive_sp;
165     Archive::Map &archive_map = Archive::GetArchiveCache ();
166     Archive::Map::iterator pos = archive_map.find (file);
167     // Don't cache a value for "archive_map.end()" below since we might
168     // delete an archive entry...
169     while (pos != archive_map.end() && pos->first == file)
170     {
171         if (pos->second->GetArchitecture().IsCompatibleMatch(arch))
172         {
173             if (pos->second->GetModificationTime() == time)
174             {
175                 return pos->second;
176             }
177             else
178             {
179                 // We have a file at the same path with the same architecture
180                 // whose modification time doesn't match. It doesn't make sense
181                 // for us to continue to use this BSD archive since we cache only
182                 // the object info which consists of file time info and also the
183                 // file offset and file size of any contianed objects. Since
184                 // this information is now out of date, we won't get the correct
185                 // information if we go and extract the file data, so we should
186                 // remove the old and outdated entry.
187                 archive_map.erase (pos);
188                 pos = archive_map.find (file);
189                 continue;
190             }
191         }
192         ++pos;
193     }
194     return archive_sp;
195 }
196 
197 ObjectContainerBSDArchive::Archive::shared_ptr
198 ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile
199 (
200     const FileSpec &file,
201     const ArchSpec &arch,
202     const TimeValue &time,
203     DataExtractor &data
204 )
205 {
206     shared_ptr archive_sp(new Archive (arch, time, data));
207     if (archive_sp)
208     {
209         if (archive_sp->ParseObjects () > 0)
210         {
211             Mutex::Locker locker(Archive::GetArchiveCacheMutex ());
212             Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp));
213         }
214         else
215         {
216             archive_sp.reset();
217         }
218     }
219     return archive_sp;
220 }
221 
222 ObjectContainerBSDArchive::Archive::Map &
223 ObjectContainerBSDArchive::Archive::GetArchiveCache ()
224 {
225     static Archive::Map g_archive_map;
226     return g_archive_map;
227 }
228 
229 Mutex &
230 ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex ()
231 {
232     static Mutex g_archive_map_mutex (Mutex::eMutexTypeRecursive);
233     return g_archive_map_mutex;
234 }
235 
236 
237 void
238 ObjectContainerBSDArchive::Initialize()
239 {
240     PluginManager::RegisterPlugin (GetPluginNameStatic(),
241                                    GetPluginDescriptionStatic(),
242                                    CreateInstance);
243 }
244 
245 void
246 ObjectContainerBSDArchive::Terminate()
247 {
248     PluginManager::UnregisterPlugin (CreateInstance);
249 }
250 
251 
252 const char *
253 ObjectContainerBSDArchive::GetPluginNameStatic()
254 {
255     return "object-container.bsd-archive";
256 }
257 
258 const char *
259 ObjectContainerBSDArchive::GetPluginDescriptionStatic()
260 {
261     return "BSD Archive object container reader.";
262 }
263 
264 
265 ObjectContainer *
266 ObjectContainerBSDArchive::CreateInstance
267 (
268     const lldb::ModuleSP &module_sp,
269     DataBufferSP& data_sp,
270     lldb::offset_t data_offset,
271     const FileSpec *file,
272     lldb::offset_t file_offset,
273     lldb::offset_t length)
274 {
275     ConstString object_name (module_sp->GetObjectName());
276     if (object_name)
277     {
278         if (data_sp)
279         {
280             // We have data, which means this is the first 512 bytes of the file
281             // Check to see if the magic bytes match and if they do, read the entire
282             // table of contents for the archive and cache it
283             DataExtractor data;
284             data.SetData (data_sp, data_offset, length);
285             if (file && data_sp && ObjectContainerBSDArchive::MagicBytesMatch(data))
286             {
287                 Timer scoped_timer (__PRETTY_FUNCTION__,
288                                     "ObjectContainerBSDArchive::CreateInstance (module = %s/%s, file = %p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")",
289                                     module_sp->GetFileSpec().GetDirectory().AsCString(),
290                                     module_sp->GetFileSpec().GetFilename().AsCString(),
291                                     file, (uint64_t) file_offset, (uint64_t) length);
292 
293                 // Map the entire .a file to be sure that we don't lose any data if the file
294                 // gets updated by a new build while this .a file is being used for debugging
295                 DataBufferSP archive_data_sp (file->MemoryMapFileContents(file_offset, length));
296                 lldb::offset_t archive_data_offset = 0;
297 
298                 Archive::shared_ptr archive_sp (Archive::FindCachedArchive (*file, module_sp->GetArchitecture(), module_sp->GetModificationTime()));
299                 std::auto_ptr<ObjectContainerBSDArchive> container_ap(new ObjectContainerBSDArchive (module_sp,
300                                                                                                      archive_data_sp,
301                                                                                                      archive_data_offset,
302                                                                                                      file,
303                                                                                                      file_offset,
304                                                                                                      length));
305 
306                 if (container_ap.get())
307                 {
308                     if (archive_sp)
309                     {
310                         // We already have this archive in our cache, use it
311                         container_ap->SetArchive (archive_sp);
312                         return container_ap.release();
313                     }
314                     else if (container_ap->ParseHeader())
315                         return container_ap.release();
316                 }
317             }
318         }
319         else
320         {
321             // No data, just check for a cached archive
322             Archive::shared_ptr archive_sp (Archive::FindCachedArchive (*file, module_sp->GetArchitecture(), module_sp->GetModificationTime()));
323             if (archive_sp)
324             {
325                 std::auto_ptr<ObjectContainerBSDArchive> container_ap(new ObjectContainerBSDArchive (module_sp, data_sp, data_offset, file, file_offset, length));
326 
327                 if (container_ap.get())
328                 {
329                     // We already have this archive in our cache, use it
330                     container_ap->SetArchive (archive_sp);
331                     return container_ap.release();
332                 }
333             }
334         }
335     }
336     return NULL;
337 }
338 
339 
340 
341 bool
342 ObjectContainerBSDArchive::MagicBytesMatch (const DataExtractor &data)
343 {
344     uint32_t offset = 0;
345     const char* armag = (const char* )data.PeekData (offset, sizeof(ar_hdr));
346     if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0)
347     {
348         armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
349         if (strncmp(armag, ARFMAG, 2) == 0)
350             return true;
351     }
352     return false;
353 }
354 
355 ObjectContainerBSDArchive::ObjectContainerBSDArchive
356 (
357     const lldb::ModuleSP &module_sp,
358     DataBufferSP& data_sp,
359     lldb::offset_t data_offset,
360     const lldb_private::FileSpec *file,
361     lldb::offset_t file_offset,
362     lldb::offset_t size
363 ) :
364     ObjectContainer (module_sp, file, file_offset, size, data_sp, data_offset),
365     m_archive_sp ()
366 {
367 }
368 void
369 ObjectContainerBSDArchive::SetArchive (Archive::shared_ptr &archive_sp)
370 {
371     m_archive_sp = archive_sp;
372 }
373 
374 
375 
376 ObjectContainerBSDArchive::~ObjectContainerBSDArchive()
377 {
378 }
379 
380 bool
381 ObjectContainerBSDArchive::ParseHeader ()
382 {
383     if (m_archive_sp.get() == NULL)
384     {
385         if (m_data.GetByteSize() > 0)
386         {
387             ModuleSP module_sp (GetModule());
388             if (module_sp)
389             {
390                 m_archive_sp = Archive::ParseAndCacheArchiveForFile (m_file,
391                                                                      module_sp->GetArchitecture(),
392                                                                      module_sp->GetModificationTime(),
393                                                                      m_data);
394             }
395             // Clear the m_data that contains the entire archive
396             // data and let our m_archive_sp hold onto the data.
397             m_data.Clear();
398         }
399     }
400     return m_archive_sp.get() != NULL;
401 }
402 
403 void
404 ObjectContainerBSDArchive::Dump (Stream *s) const
405 {
406     s->Printf("%p: ", this);
407     s->Indent();
408     const size_t num_archs = GetNumArchitectures();
409     const size_t num_objects = GetNumObjects();
410     s->Printf("ObjectContainerBSDArchive, num_archs = %lu, num_objects = %lu", num_archs, num_objects);
411     uint32_t i;
412     ArchSpec arch;
413     s->IndentMore();
414     for (i=0; i<num_archs; i++)
415     {
416         s->Indent();
417         GetArchitectureAtIndex(i, arch);
418         s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName());
419     }
420     for (i=0; i<num_objects; i++)
421     {
422         s->Indent();
423         s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex (i));
424     }
425     s->IndentLess();
426     s->EOL();
427 }
428 
429 ObjectFileSP
430 ObjectContainerBSDArchive::GetObjectFile (const FileSpec *file)
431 {
432     ModuleSP module_sp (GetModule());
433     if (module_sp)
434     {
435         if (module_sp->GetObjectName() && m_archive_sp)
436         {
437             Object *object = m_archive_sp->FindObject (module_sp->GetObjectName());
438             if (object)
439             {
440                 lldb::offset_t data_offset = m_offset + object->ar_file_offset;
441                 return ObjectFile::FindPlugin (module_sp,
442                                                file,
443                                                m_offset + object->ar_file_offset,
444                                                object->ar_file_size,
445                                                m_archive_sp->GetData().GetSharedDataBuffer(),
446                                                data_offset);
447             }
448         }
449     }
450     return ObjectFileSP();
451 }
452 
453 
454 //------------------------------------------------------------------
455 // PluginInterface protocol
456 //------------------------------------------------------------------
457 const char *
458 ObjectContainerBSDArchive::GetPluginName()
459 {
460     return "object-container.bsd-archive";
461 }
462 
463 const char *
464 ObjectContainerBSDArchive::GetShortPluginName()
465 {
466     return GetPluginNameStatic();
467 }
468 
469 uint32_t
470 ObjectContainerBSDArchive::GetPluginVersion()
471 {
472     return 1;
473 }
474 
475