1 //===-- DWARFDebugInfo.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 "SymbolFileDWARF.h"
11 
12 #include <algorithm>
13 #include <set>
14 
15 #include "lldb/Core/RegularExpression.h"
16 #include "lldb/Core/Stream.h"
17 #include "lldb/Host/PosixApi.h"
18 #include "lldb/Symbol/ObjectFile.h"
19 
20 #include "DWARFDebugAranges.h"
21 #include "DWARFDebugInfo.h"
22 #include "DWARFCompileUnit.h"
23 #include "DWARFDebugAranges.h"
24 #include "DWARFDebugInfoEntry.h"
25 #include "DWARFFormValue.h"
26 #include "LogChannelDWARF.h"
27 
28 using namespace lldb;
29 using namespace lldb_private;
30 using namespace std;
31 
32 //----------------------------------------------------------------------
33 // Constructor
34 //----------------------------------------------------------------------
35 DWARFDebugInfo::DWARFDebugInfo() :
36     m_dwarf2Data(NULL),
37     m_compile_units(),
38     m_cu_aranges_ap ()
39 {
40 }
41 
42 //----------------------------------------------------------------------
43 // SetDwarfData
44 //----------------------------------------------------------------------
45 void
46 DWARFDebugInfo::SetDwarfData(SymbolFileDWARF* dwarf2Data)
47 {
48     m_dwarf2Data = dwarf2Data;
49     m_compile_units.clear();
50 }
51 
52 
53 DWARFDebugAranges &
54 DWARFDebugInfo::GetCompileUnitAranges ()
55 {
56     if (m_cu_aranges_ap.get() == NULL && m_dwarf2Data)
57     {
58         Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_ARANGES));
59 
60         m_cu_aranges_ap.reset (new DWARFDebugAranges());
61         const DWARFDataExtractor &debug_aranges_data = m_dwarf2Data->get_debug_aranges_data();
62         if (debug_aranges_data.GetByteSize() > 0)
63         {
64             if (log)
65                 log->Printf ("DWARFDebugInfo::GetCompileUnitAranges() for \"%s\" from .debug_aranges",
66                              m_dwarf2Data->GetObjectFile()->GetFileSpec().GetPath().c_str());
67             m_cu_aranges_ap->Extract (debug_aranges_data);
68 
69         }
70 
71         // Make a list of all CUs represented by the arange data in the file.
72         std::set<dw_offset_t> cus_with_data;
73         for (size_t n=0;n<m_cu_aranges_ap.get()->GetNumRanges();n++)
74         {
75             dw_offset_t offset = m_cu_aranges_ap.get()->OffsetAtIndex(n);
76             if (offset != DW_INVALID_OFFSET)
77                 cus_with_data.insert (offset);
78         }
79 
80         // Manually build arange data for everything that wasn't in the .debug_aranges table.
81         bool printed = false;
82         const size_t num_compile_units = GetNumCompileUnits();
83         for (size_t idx = 0; idx < num_compile_units; ++idx)
84         {
85             DWARFCompileUnit* cu = GetCompileUnitAtIndex(idx);
86 
87             dw_offset_t offset = cu->GetOffset();
88             if (cus_with_data.find(offset) == cus_with_data.end())
89             {
90                 if (log)
91                 {
92                     if (!printed)
93                         log->Printf ("DWARFDebugInfo::GetCompileUnitAranges() for \"%s\" by parsing",
94                                      m_dwarf2Data->GetObjectFile()->GetFileSpec().GetPath().c_str());
95                     printed = true;
96                 }
97                 cu->BuildAddressRangeTable (m_dwarf2Data, m_cu_aranges_ap.get());
98             }
99         }
100 
101         const bool minimize = true;
102         m_cu_aranges_ap->Sort (minimize);
103     }
104     return *m_cu_aranges_ap.get();
105 }
106 
107 void
108 DWARFDebugInfo::ParseCompileUnitHeadersIfNeeded()
109 {
110     if (m_compile_units.empty())
111     {
112         if (m_dwarf2Data != NULL)
113         {
114             lldb::offset_t offset = 0;
115             const DWARFDataExtractor &debug_info_data = m_dwarf2Data->get_debug_info_data();
116             while (debug_info_data.ValidOffset(offset))
117             {
118                 DWARFCompileUnitSP cu_sp(new DWARFCompileUnit(m_dwarf2Data));
119                 // Out of memory?
120                 if (cu_sp.get() == NULL)
121                     break;
122 
123                 if (cu_sp->Extract(debug_info_data, &offset) == false)
124                     break;
125 
126                 m_compile_units.push_back(cu_sp);
127 
128                 offset = cu_sp->GetNextCompileUnitOffset();
129             }
130         }
131     }
132 }
133 
134 size_t
135 DWARFDebugInfo::GetNumCompileUnits()
136 {
137     ParseCompileUnitHeadersIfNeeded();
138     return m_compile_units.size();
139 }
140 
141 DWARFCompileUnit*
142 DWARFDebugInfo::GetCompileUnitAtIndex(uint32_t idx)
143 {
144     DWARFCompileUnit* cu = NULL;
145     if (idx < GetNumCompileUnits())
146         cu = m_compile_units[idx].get();
147     return cu;
148 }
149 
150 bool
151 DWARFDebugInfo::ContainsCompileUnit (const DWARFCompileUnit *cu) const
152 {
153     // Not a verify efficient function, but it is handy for use in assertions
154     // to make sure that a compile unit comes from a debug information file.
155     CompileUnitColl::const_iterator end_pos = m_compile_units.end();
156     CompileUnitColl::const_iterator pos;
157 
158     for (pos = m_compile_units.begin(); pos != end_pos; ++pos)
159     {
160         if (pos->get() == cu)
161             return true;
162     }
163     return false;
164 }
165 
166 bool
167 DWARFDebugInfo::OffsetLessThanCompileUnitOffset (dw_offset_t offset, const DWARFCompileUnitSP& cu_sp)
168 {
169     return offset < cu_sp->GetOffset();
170 }
171 
172 DWARFCompileUnit *
173 DWARFDebugInfo::GetCompileUnit(dw_offset_t cu_offset, uint32_t* idx_ptr)
174 {
175     DWARFCompileUnitSP cu_sp;
176     uint32_t cu_idx = DW_INVALID_INDEX;
177     if (cu_offset != DW_INVALID_OFFSET)
178     {
179         ParseCompileUnitHeadersIfNeeded();
180 
181         // Watch out for single compile unit executable as they are pretty common
182         const size_t num_cus = m_compile_units.size();
183         if (num_cus == 1)
184         {
185             if (m_compile_units[0]->GetOffset() == cu_offset)
186             {
187                 cu_sp = m_compile_units[0];
188                 cu_idx = 0;
189             }
190         }
191         else if (num_cus)
192         {
193             CompileUnitColl::const_iterator end_pos = m_compile_units.end();
194             CompileUnitColl::const_iterator begin_pos = m_compile_units.begin();
195             CompileUnitColl::const_iterator pos = std::upper_bound(begin_pos, end_pos, cu_offset, OffsetLessThanCompileUnitOffset);
196             if (pos != begin_pos)
197             {
198                 --pos;
199                 if ((*pos)->GetOffset() == cu_offset)
200                 {
201                     cu_sp = *pos;
202                     cu_idx = std::distance(begin_pos, pos);
203                 }
204             }
205         }
206     }
207     if (idx_ptr)
208         *idx_ptr = cu_idx;
209     return cu_sp.get();
210 }
211 
212 DWARFCompileUnit *
213 DWARFDebugInfo::GetCompileUnit (const DIERef& die_ref)
214 {
215     if (die_ref.cu_offset == DW_INVALID_OFFSET)
216         return GetCompileUnitContainingDIEOffset(die_ref.die_offset);
217     else
218         return GetCompileUnit(die_ref.cu_offset);
219 }
220 
221 DWARFCompileUnit*
222 DWARFDebugInfo::GetCompileUnitContainingDIEOffset(dw_offset_t die_offset)
223 {
224     ParseCompileUnitHeadersIfNeeded();
225 
226     DWARFCompileUnitSP cu_sp;
227 
228     // Watch out for single compile unit executable as they are pretty common
229     const size_t num_cus = m_compile_units.size();
230     if (num_cus == 1)
231     {
232         if (m_compile_units[0]->ContainsDIEOffset(die_offset))
233             return m_compile_units[0].get();
234     }
235     else if (num_cus)
236     {
237         CompileUnitColl::const_iterator end_pos = m_compile_units.end();
238         CompileUnitColl::const_iterator begin_pos = m_compile_units.begin();
239         CompileUnitColl::const_iterator pos = std::upper_bound(begin_pos, end_pos, die_offset, OffsetLessThanCompileUnitOffset);
240         if (pos != begin_pos)
241         {
242             --pos;
243             if ((*pos)->ContainsDIEOffset(die_offset))
244                 return (*pos).get();
245         }
246     }
247 
248     return nullptr;
249 }
250 
251 DWARFDIE
252 DWARFDebugInfo::GetDIEForDIEOffset(dw_offset_t die_offset)
253 {
254     DWARFCompileUnit* cu = GetCompileUnitContainingDIEOffset(die_offset);
255     if (cu)
256         return cu->GetDIE(die_offset);
257     return DWARFDIE();
258 }
259 
260 //----------------------------------------------------------------------
261 // GetDIE()
262 //
263 // Get the DIE (Debug Information Entry) with the specified offset.
264 //----------------------------------------------------------------------
265 DWARFDIE
266 DWARFDebugInfo::GetDIE(const DIERef& die_ref)
267 {
268     DWARFCompileUnit *cu = GetCompileUnit(die_ref);
269     if (cu)
270         return cu->GetDIE (die_ref.die_offset);
271     return DWARFDIE();    // Not found
272 }
273 
274 //----------------------------------------------------------------------
275 // Parse
276 //
277 // Parses the .debug_info section and uses the .debug_abbrev section
278 // and various other sections in the SymbolFileDWARF class and calls the
279 // supplied callback function each time a compile unit header, or debug
280 // information entry is successfully parsed. This function can be used
281 // for different tasks such as parsing the file contents into a
282 // structured data, dumping, verifying and much more.
283 //----------------------------------------------------------------------
284 void
285 DWARFDebugInfo::Parse(SymbolFileDWARF* dwarf2Data, Callback callback, void* userData)
286 {
287     if (dwarf2Data)
288     {
289         lldb::offset_t offset = 0;
290         uint32_t depth = 0;
291         DWARFCompileUnitSP cu(new DWARFCompileUnit(dwarf2Data));
292         if (cu.get() == NULL)
293             return;
294         DWARFDebugInfoEntry die;
295 
296         while (cu->Extract(dwarf2Data->get_debug_info_data(), &offset))
297         {
298             const dw_offset_t next_cu_offset = cu->GetNextCompileUnitOffset();
299 
300             depth = 0;
301             // Call the callback function with no DIE pointer for the compile unit
302             // and get the offset that we are to continue to parse from
303             offset = callback(dwarf2Data, cu.get(), NULL, offset, depth, userData);
304 
305             // Make sure we are within our compile unit
306             if (offset < next_cu_offset)
307             {
308                 // We are in our compile unit, parse starting at the offset
309                 // we were told to parse
310                 bool done = false;
311                 while (!done && die.Extract(dwarf2Data, cu.get(), &offset))
312                 {
313                     // Call the callback function with DIE pointer that falls within the compile unit
314                     offset = callback(dwarf2Data, cu.get(), &die, offset, depth, userData);
315 
316                     if (die.IsNULL())
317                     {
318                         if (depth)
319                             --depth;
320                         else
321                             done = true;    // We are done with this compile unit!
322                     }
323                     else if (die.HasChildren())
324                         ++depth;
325                 }
326             }
327 
328             // Make sure the offset returned is valid, and if not stop parsing.
329             // Returning DW_INVALID_OFFSET from this callback is a good way to end
330             // all parsing
331             if (!dwarf2Data->get_debug_info_data().ValidOffset(offset))
332                 break;
333 
334             // See if during the callback anyone retained a copy of the compile
335             // unit other than ourselves and if so, let whomever did own the object
336             // and create a new one for our own use!
337             if (!cu.unique())
338                 cu.reset(new DWARFCompileUnit(dwarf2Data));
339 
340 
341             // Make sure we start on a proper
342             offset = next_cu_offset;
343         }
344     }
345 }
346 
347 typedef struct DumpInfo
348 {
349     DumpInfo(Stream* init_strm, uint32_t off, uint32_t depth) :
350         strm(init_strm),
351         die_offset(off),
352         recurse_depth(depth),
353         found_depth(UINT32_MAX),
354         found_die(false),
355         ancestors()
356     {
357     }
358     Stream* strm;
359     const uint32_t die_offset;
360     const uint32_t recurse_depth;
361     uint32_t found_depth;
362     bool found_die;
363     std::vector<DWARFDebugInfoEntry> ancestors;
364 
365     DISALLOW_COPY_AND_ASSIGN(DumpInfo);
366 } DumpInfo;
367 
368 //----------------------------------------------------------------------
369 // DumpCallback
370 //
371 // A callback function for the static DWARFDebugInfo::Parse() function
372 // that gets called each time a compile unit header or debug information
373 // entry is successfully parsed.
374 //
375 // This function dump DWARF information and obey recurse depth and
376 // whether a single DIE is to be dumped (or all of the data).
377 //----------------------------------------------------------------------
378 static dw_offset_t DumpCallback
379 (
380     SymbolFileDWARF* dwarf2Data,
381     DWARFCompileUnit* cu,
382     DWARFDebugInfoEntry* die,
383     const dw_offset_t next_offset,
384     const uint32_t curr_depth,
385     void* userData
386 )
387 {
388     DumpInfo* dumpInfo = (DumpInfo*)userData;
389     Stream *s = dumpInfo->strm;
390     bool show_parents = s->GetFlags().Test(DWARFDebugInfo::eDumpFlag_ShowAncestors);
391 
392     if (die)
393     {
394         // Are we dumping everything?
395         if (dumpInfo->die_offset == DW_INVALID_OFFSET)
396         {
397             // Yes we are dumping everything. Obey our recurse level though
398             if (curr_depth < dumpInfo->recurse_depth)
399                 die->Dump(dwarf2Data, cu, *s, 0);
400         }
401         else
402         {
403             // We are dumping a specific DIE entry by offset
404             if (dumpInfo->die_offset == die->GetOffset())
405             {
406                 // We found the DIE we were looking for, dump it!
407                 if (show_parents)
408                 {
409                     s->SetIndentLevel(0);
410                     const uint32_t num_ancestors = dumpInfo->ancestors.size();
411                     if (num_ancestors > 0)
412                     {
413                         for (uint32_t i=0; i<num_ancestors-1; ++i)
414                         {
415                             dumpInfo->ancestors[i].Dump(dwarf2Data, cu, *s, 0);
416                             s->IndentMore();
417                         }
418                     }
419                 }
420 
421                 dumpInfo->found_depth = curr_depth;
422 
423                 die->Dump(dwarf2Data, cu, *s, 0);
424 
425                 // Note that we found the DIE we were looking for
426                 dumpInfo->found_die = true;
427 
428                 // Since we are dumping a single DIE, if there are no children we are done!
429                 if (!die->HasChildren() || dumpInfo->recurse_depth == 0)
430                     return DW_INVALID_OFFSET;   // Return an invalid address to end parsing
431             }
432             else if (dumpInfo->found_die)
433             {
434                 // Are we done with all the children?
435                 if (curr_depth <= dumpInfo->found_depth)
436                     return DW_INVALID_OFFSET;
437 
438                 // We have already found our DIE and are printing it's children. Obey
439                 // our recurse depth and return an invalid offset if we get done
440                 // dumping all of the children
441                 if (dumpInfo->recurse_depth == UINT32_MAX || curr_depth <= dumpInfo->found_depth + dumpInfo->recurse_depth)
442                     die->Dump(dwarf2Data, cu, *s, 0);
443             }
444             else if (dumpInfo->die_offset > die->GetOffset())
445             {
446                 if (show_parents)
447                     dumpInfo->ancestors.back() = *die;
448             }
449         }
450 
451         // Keep up with our indent level
452         if (die->IsNULL())
453         {
454             if (show_parents)
455                 dumpInfo->ancestors.pop_back();
456 
457             if (curr_depth <= 1)
458                 return cu->GetNextCompileUnitOffset();
459             else
460                 s->IndentLess();
461         }
462         else if (die->HasChildren())
463         {
464             if (show_parents)
465             {
466                 DWARFDebugInfoEntry null_die;
467                 dumpInfo->ancestors.push_back(null_die);
468             }
469             s->IndentMore();
470         }
471     }
472     else
473     {
474         if (cu == NULL)
475             s->PutCString("NULL - cu");
476         // We have a compile unit, reset our indent level to zero just in case
477         s->SetIndentLevel(0);
478 
479         // See if we are dumping everything?
480         if (dumpInfo->die_offset == DW_INVALID_OFFSET)
481         {
482             // We are dumping everything
483             if (cu)
484             {
485                 cu->Dump(s);
486                 return cu->GetFirstDIEOffset(); // Return true to parse all DIEs in this Compile Unit
487             }
488             else
489             {
490                 return DW_INVALID_OFFSET;
491             }
492         }
493         else
494         {
495             if (show_parents)
496             {
497                 dumpInfo->ancestors.clear();
498                 dumpInfo->ancestors.resize(1);
499             }
500 
501             // We are dumping only a single DIE possibly with it's children and
502             // we must find it's compile unit before we can dump it properly
503             if (cu && dumpInfo->die_offset < cu->GetFirstDIEOffset())
504             {
505                 // Not found, maybe the DIE offset provided wasn't correct?
506             //  *ostrm_ptr << "DIE at offset " << HEX32 << dumpInfo->die_offset << " was not found." << endl;
507                 return DW_INVALID_OFFSET;
508             }
509             else
510             {
511                 // See if the DIE is in this compile unit?
512                 if (cu && dumpInfo->die_offset < cu->GetNextCompileUnitOffset())
513                 {
514                     // This DIE is in this compile unit!
515                     if (s->GetVerbose())
516                         cu->Dump(s); // Dump the compile unit for the DIE in verbose mode
517 
518                     return next_offset;
519                 //  // We found our compile unit that contains our DIE, just skip to dumping the requested DIE...
520                 //  return dumpInfo->die_offset;
521                 }
522                 else
523                 {
524                     // Skip to the next compile unit as the DIE isn't in the current one!
525                     if (cu)
526                     {
527                         return cu->GetNextCompileUnitOffset();
528                     }
529                     else
530                     {
531                         return DW_INVALID_OFFSET;
532                     }
533                 }
534             }
535         }
536     }
537 
538     // Just return the current offset to parse the next CU or DIE entry
539     return next_offset;
540 }
541 
542 //----------------------------------------------------------------------
543 // Dump
544 //
545 // Dump the information in the .debug_info section to the specified
546 // ostream. If die_offset is valid, a single DIE will be dumped. If the
547 // die_offset is invalid, all the DWARF information will be dumped. Both
548 // cases will obey a "recurse_depth" or how deep to traverse into the
549 // children of each DIE entry. A recurse_depth of zero will dump all
550 // compile unit headers. A recurse_depth of 1 will dump all compile unit
551 // headers and the DW_TAG_compile unit tags. A depth of 2 will also
552 // dump all types and functions.
553 //----------------------------------------------------------------------
554 void
555 DWARFDebugInfo::Dump
556 (
557     Stream *s,
558     SymbolFileDWARF* dwarf2Data,
559     const uint32_t die_offset,
560     const uint32_t recurse_depth
561 )
562 {
563     DumpInfo dumpInfo(s, die_offset, recurse_depth);
564     s->PutCString(".debug_info contents");
565     if (dwarf2Data->get_debug_info_data().GetByteSize() > 0)
566     {
567         if (die_offset == DW_INVALID_OFFSET)
568             s->PutCString(":\n");
569         else
570         {
571             s->Printf(" for DIE entry at .debug_info[0x%8.8x]", die_offset);
572             if (recurse_depth != UINT32_MAX)
573                 s->Printf(" recursing %u levels deep.", recurse_depth);
574             s->EOL();
575         }
576     }
577     else
578     {
579         s->PutCString(": < EMPTY >\n");
580         return;
581     }
582     DWARFDebugInfo::Parse(dwarf2Data, DumpCallback, &dumpInfo);
583 }
584 
585 
586 //----------------------------------------------------------------------
587 // Dump
588 //
589 // Dump the contents of this DWARFDebugInfo object as has been parsed
590 // and/or modified after it has been parsed.
591 //----------------------------------------------------------------------
592 void
593 DWARFDebugInfo::Dump (Stream *s, const uint32_t die_offset, const uint32_t recurse_depth)
594 {
595     DumpInfo dumpInfo(s, die_offset, recurse_depth);
596 
597     s->PutCString("Dumping .debug_info section from internal representation\n");
598 
599     CompileUnitColl::const_iterator pos;
600     uint32_t curr_depth = 0;
601     ParseCompileUnitHeadersIfNeeded();
602     for (pos = m_compile_units.begin(); pos != m_compile_units.end(); ++pos)
603     {
604         DWARFCompileUnit *cu = pos->get();
605         DumpCallback(m_dwarf2Data, cu, NULL, 0, curr_depth, &dumpInfo);
606 
607         const DWARFDIE die = cu->DIE();
608         if (die)
609             die.Dump(s, recurse_depth);
610     }
611 }
612 
613 
614 //----------------------------------------------------------------------
615 // FindCallbackString
616 //
617 // A callback function for the static DWARFDebugInfo::Parse() function
618 // that gets called each time a compile unit header or debug information
619 // entry is successfully parsed.
620 //
621 // This function will find the die_offset of any items whose DW_AT_name
622 // matches the given string
623 //----------------------------------------------------------------------
624 typedef struct FindCallbackStringInfoTag
625 {
626     const char* name;
627     bool ignore_case;
628     RegularExpression* regex;
629     vector<dw_offset_t>& die_offsets;
630 } FindCallbackStringInfo;
631 
632 static dw_offset_t FindCallbackString
633 (
634     SymbolFileDWARF* dwarf2Data,
635     DWARFCompileUnit* cu,
636     DWARFDebugInfoEntry* die,
637     const dw_offset_t next_offset,
638     const uint32_t curr_depth,
639     void* userData
640 )
641 {
642     FindCallbackStringInfo* info = (FindCallbackStringInfo*)userData;
643 
644     if (die)
645     {
646         const char* die_name = die->GetName(dwarf2Data, cu);
647         if (die_name)
648         {
649             if (info->regex)
650             {
651                 if (info->regex->Execute(die_name))
652                     info->die_offsets.push_back(die->GetOffset());
653             }
654             else
655             {
656                 if ((info->ignore_case ? strcasecmp(die_name, info->name) : strcmp(die_name, info->name)) == 0)
657                     info->die_offsets.push_back(die->GetOffset());
658             }
659         }
660     }
661 
662     // Just return the current offset to parse the next CU or DIE entry
663     return next_offset;
664 }
665 
666 //----------------------------------------------------------------------
667 // Find
668 //
669 // Finds all DIE that have a specific DW_AT_name attribute by manually
670 // searching through the debug information (not using the
671 // .debug_pubnames section). The string must match the entire name
672 // and case sensitive searches are an option.
673 //----------------------------------------------------------------------
674 bool
675 DWARFDebugInfo::Find(const char* name, bool ignore_case, vector<dw_offset_t>& die_offsets) const
676 {
677     die_offsets.clear();
678     if (name && name[0])
679     {
680         FindCallbackStringInfo info = { name, ignore_case, NULL, die_offsets };
681         DWARFDebugInfo::Parse(m_dwarf2Data, FindCallbackString, &info);
682     }
683     return !die_offsets.empty();
684 }
685 
686 //----------------------------------------------------------------------
687 // Find
688 //
689 // Finds all DIE that have a specific DW_AT_name attribute by manually
690 // searching through the debug information (not using the
691 // .debug_pubnames section). The string must match the supplied regular
692 // expression.
693 //----------------------------------------------------------------------
694 bool
695 DWARFDebugInfo::Find(RegularExpression& re, vector<dw_offset_t>& die_offsets) const
696 {
697     die_offsets.clear();
698     FindCallbackStringInfo info = { NULL, false, &re, die_offsets };
699     DWARFDebugInfo::Parse(m_dwarf2Data, FindCallbackString, &info);
700     return !die_offsets.empty();
701 }
702