1 //===-- DWARFCompileUnit.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 "DWARFCompileUnit.h"
11 
12 #include "lldb/Core/Mangled.h"
13 #include "lldb/Core/Module.h"
14 #include "lldb/Core/Stream.h"
15 #include "lldb/Core/Timer.h"
16 #include "lldb/Symbol/CompileUnit.h"
17 #include "lldb/Symbol/LineTable.h"
18 #include "lldb/Symbol/ObjectFile.h"
19 #include "lldb/Target/ObjCLanguageRuntime.h"
20 
21 #include "DWARFDebugAbbrev.h"
22 #include "DWARFDebugAranges.h"
23 #include "DWARFDebugInfo.h"
24 #include "DWARFDIECollection.h"
25 #include "DWARFFormValue.h"
26 #include "LogChannelDWARF.h"
27 #include "NameToDIE.h"
28 #include "SymbolFileDWARF.h"
29 #include "SymbolFileDWARFDebugMap.h"
30 
31 using namespace lldb;
32 using namespace lldb_private;
33 using namespace std;
34 
35 
36 extern int g_verbose;
37 
38 DWARFCompileUnit::DWARFCompileUnit(SymbolFileDWARF* dwarf2Data) :
39     m_dwarf2Data    (dwarf2Data),
40     m_abbrevs       (NULL),
41     m_user_data     (NULL),
42     m_die_array     (),
43     m_func_aranges_ap (),
44     m_base_addr     (0),
45     m_offset        (DW_INVALID_OFFSET),
46     m_length        (0),
47     m_version       (0),
48     m_addr_size     (DWARFCompileUnit::GetDefaultAddressSize()),
49     m_producer      (eProducerInvalid),
50     m_producer_version_major (0),
51     m_producer_version_minor (0),
52     m_producer_version_update (0)
53 {
54 }
55 
56 void
57 DWARFCompileUnit::Clear()
58 {
59     m_offset        = DW_INVALID_OFFSET;
60     m_length        = 0;
61     m_version       = 0;
62     m_abbrevs       = NULL;
63     m_addr_size     = DWARFCompileUnit::GetDefaultAddressSize();
64     m_base_addr     = 0;
65     m_die_array.clear();
66     m_func_aranges_ap.reset();
67     m_user_data     = NULL;
68     m_producer      = eProducerInvalid;
69 }
70 
71 bool
72 DWARFCompileUnit::Extract(const DWARFDataExtractor &debug_info, lldb::offset_t *offset_ptr)
73 {
74     Clear();
75 
76     m_offset = *offset_ptr;
77 
78     if (debug_info.ValidOffset(*offset_ptr))
79     {
80         dw_offset_t abbr_offset;
81         const DWARFDebugAbbrev *abbr = m_dwarf2Data->DebugAbbrev();
82         m_length        = debug_info.GetU32(offset_ptr);
83         m_version       = debug_info.GetU16(offset_ptr);
84         abbr_offset     = debug_info.GetU32(offset_ptr);
85         m_addr_size     = debug_info.GetU8 (offset_ptr);
86 
87         bool length_OK = debug_info.ValidOffset(GetNextCompileUnitOffset()-1);
88         bool version_OK = SymbolFileDWARF::SupportedVersion(m_version);
89         bool abbr_offset_OK = m_dwarf2Data->get_debug_abbrev_data().ValidOffset(abbr_offset);
90         bool addr_size_OK = ((m_addr_size == 4) || (m_addr_size == 8));
91 
92         if (length_OK && version_OK && addr_size_OK && abbr_offset_OK && abbr != NULL)
93         {
94             m_abbrevs = abbr->GetAbbreviationDeclarationSet(abbr_offset);
95             return true;
96         }
97 
98         // reset the offset to where we tried to parse from if anything went wrong
99         *offset_ptr = m_offset;
100     }
101 
102     return false;
103 }
104 
105 
106 void
107 DWARFCompileUnit::ClearDIEs(bool keep_compile_unit_die)
108 {
109     if (m_die_array.size() > 1)
110     {
111         // std::vectors never get any smaller when resized to a smaller size,
112         // or when clear() or erase() are called, the size will report that it
113         // is smaller, but the memory allocated remains intact (call capacity()
114         // to see this). So we need to create a temporary vector and swap the
115         // contents which will cause just the internal pointers to be swapped
116         // so that when "tmp_array" goes out of scope, it will destroy the
117         // contents.
118 
119         // Save at least the compile unit DIE
120         DWARFDebugInfoEntry::collection tmp_array;
121         m_die_array.swap(tmp_array);
122         if (keep_compile_unit_die)
123             m_die_array.push_back(tmp_array.front());
124     }
125 }
126 
127 //----------------------------------------------------------------------
128 // ParseCompileUnitDIEsIfNeeded
129 //
130 // Parses a compile unit and indexes its DIEs if it hasn't already been
131 // done.
132 //----------------------------------------------------------------------
133 size_t
134 DWARFCompileUnit::ExtractDIEsIfNeeded (bool cu_die_only)
135 {
136     const size_t initial_die_array_size = m_die_array.size();
137     if ((cu_die_only && initial_die_array_size > 0) || initial_die_array_size > 1)
138         return 0; // Already parsed
139 
140     Timer scoped_timer (__PRETTY_FUNCTION__,
141                         "%8.8x: DWARFCompileUnit::ExtractDIEsIfNeeded( cu_die_only = %i )",
142                         m_offset,
143                         cu_die_only);
144 
145     // Set the offset to that of the first DIE and calculate the start of the
146     // next compilation unit header.
147     lldb::offset_t offset = GetFirstDIEOffset();
148     lldb::offset_t next_cu_offset = GetNextCompileUnitOffset();
149 
150     DWARFDebugInfoEntry die;
151         // Keep a flat array of the DIE for binary lookup by DIE offset
152     if (!cu_die_only)
153     {
154         Log *log (LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO | DWARF_LOG_LOOKUPS));
155         if (log)
156         {
157             m_dwarf2Data->GetObjectFile()->GetModule()->LogMessageVerboseBacktrace (log,
158                                                                                     "DWARFCompileUnit::ExtractDIEsIfNeeded () for compile unit at .debug_info[0x%8.8x]",
159                                                                                     GetOffset());
160         }
161     }
162 
163     uint32_t depth = 0;
164     // We are in our compile unit, parse starting at the offset
165     // we were told to parse
166     const DWARFDataExtractor& debug_info_data = m_dwarf2Data->get_debug_info_data();
167     std::vector<uint32_t> die_index_stack;
168     die_index_stack.reserve(32);
169     die_index_stack.push_back(0);
170     bool prev_die_had_children = false;
171     const uint8_t *fixed_form_sizes = DWARFFormValue::GetFixedFormSizesForAddressSize (GetAddressByteSize());
172     while (offset < next_cu_offset &&
173            die.FastExtract (debug_info_data, this, fixed_form_sizes, &offset))
174     {
175 //        if (log)
176 //            log->Printf("0x%8.8x: %*.*s%s%s",
177 //                        die.GetOffset(),
178 //                        depth * 2, depth * 2, "",
179 //                        DW_TAG_value_to_name (die.Tag()),
180 //                        die.HasChildren() ? " *" : "");
181 
182         const bool null_die = die.IsNULL();
183         if (depth == 0)
184         {
185             uint64_t base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
186             if (base_addr == LLDB_INVALID_ADDRESS)
187                 base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_entry_pc, 0);
188             SetBaseAddress (base_addr);
189             if (initial_die_array_size == 0)
190                 AddDIE (die);
191             if (cu_die_only)
192                 return 1;
193         }
194         else
195         {
196             if (null_die)
197             {
198                 if (prev_die_had_children)
199                 {
200                     // This will only happen if a DIE says is has children
201                     // but all it contains is a NULL tag. Since we are removing
202                     // the NULL DIEs from the list (saves up to 25% in C++ code),
203                     // we need a way to let the DIE know that it actually doesn't
204                     // have children.
205                     if (!m_die_array.empty())
206                         m_die_array.back().SetEmptyChildren(true);
207                 }
208             }
209             else
210             {
211                 die.SetParentIndex(m_die_array.size() - die_index_stack[depth-1]);
212 
213                 if (die_index_stack.back())
214                     m_die_array[die_index_stack.back()].SetSiblingIndex(m_die_array.size()-die_index_stack.back());
215 
216                 // Only push the DIE if it isn't a NULL DIE
217                     m_die_array.push_back(die);
218             }
219         }
220 
221         if (null_die)
222         {
223             // NULL DIE.
224             if (!die_index_stack.empty())
225                 die_index_stack.pop_back();
226 
227             if (depth > 0)
228                 --depth;
229             if (depth == 0)
230                 break;  // We are done with this compile unit!
231 
232             prev_die_had_children = false;
233         }
234         else
235         {
236             die_index_stack.back() = m_die_array.size() - 1;
237             // Normal DIE
238             const bool die_has_children = die.HasChildren();
239             if (die_has_children)
240             {
241                 die_index_stack.push_back(0);
242                 ++depth;
243             }
244             prev_die_had_children = die_has_children;
245         }
246     }
247 
248     // Give a little bit of info if we encounter corrupt DWARF (our offset
249     // should always terminate at or before the start of the next compilation
250     // unit header).
251     if (offset > next_cu_offset)
252     {
253         m_dwarf2Data->GetObjectFile()->GetModule()->ReportWarning ("DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8" PRIx64 "\n",
254                                                                    GetOffset(),
255                                                                    offset);
256     }
257 
258     // Since std::vector objects will double their size, we really need to
259     // make a new array with the perfect size so we don't end up wasting
260     // space. So here we copy and swap to make sure we don't have any extra
261     // memory taken up.
262 
263     if (m_die_array.size () < m_die_array.capacity())
264     {
265         DWARFDebugInfoEntry::collection exact_size_die_array (m_die_array.begin(), m_die_array.end());
266         exact_size_die_array.swap (m_die_array);
267     }
268     Log *verbose_log (LogChannelDWARF::GetLogIfAll (DWARF_LOG_DEBUG_INFO | DWARF_LOG_VERBOSE));
269     if (verbose_log)
270     {
271         StreamString strm;
272         Dump(&strm);
273         if (m_die_array.empty())
274             strm.Printf("error: no DIE for compile unit");
275         else
276             m_die_array[0].Dump(m_dwarf2Data, this, strm, UINT32_MAX);
277         verbose_log->PutCString (strm.GetString().c_str());
278     }
279 
280     return m_die_array.size();
281 }
282 
283 
284 dw_offset_t
285 DWARFCompileUnit::GetAbbrevOffset() const
286 {
287     return m_abbrevs ? m_abbrevs->GetOffset() : DW_INVALID_OFFSET;
288 }
289 
290 
291 
292 bool
293 DWARFCompileUnit::Verify(Stream *s) const
294 {
295     const DWARFDataExtractor& debug_info = m_dwarf2Data->get_debug_info_data();
296     bool valid_offset = debug_info.ValidOffset(m_offset);
297     bool length_OK = debug_info.ValidOffset(GetNextCompileUnitOffset()-1);
298     bool version_OK = SymbolFileDWARF::SupportedVersion(m_version);
299     bool abbr_offset_OK = m_dwarf2Data->get_debug_abbrev_data().ValidOffset(GetAbbrevOffset());
300     bool addr_size_OK = ((m_addr_size == 4) || (m_addr_size == 8));
301     bool verbose = s->GetVerbose();
302     if (valid_offset && length_OK && version_OK && addr_size_OK && abbr_offset_OK)
303     {
304         if (verbose)
305             s->Printf("    0x%8.8x: OK\n", m_offset);
306         return true;
307     }
308     else
309     {
310         s->Printf("    0x%8.8x: ", m_offset);
311 
312         m_dwarf2Data->get_debug_info_data().Dump (s, m_offset, lldb::eFormatHex, 1, Size(), 32, LLDB_INVALID_ADDRESS, 0, 0);
313         s->EOL();
314         if (valid_offset)
315         {
316             if (!length_OK)
317                 s->Printf("        The length (0x%8.8x) for this compile unit is too large for the .debug_info provided.\n", m_length);
318             if (!version_OK)
319                 s->Printf("        The 16 bit compile unit header version is not supported.\n");
320             if (!abbr_offset_OK)
321                 s->Printf("        The offset into the .debug_abbrev section (0x%8.8x) is not valid.\n", GetAbbrevOffset());
322             if (!addr_size_OK)
323                 s->Printf("        The address size is unsupported: 0x%2.2x\n", m_addr_size);
324         }
325         else
326             s->Printf("        The start offset of the compile unit header in the .debug_info is invalid.\n");
327     }
328     return false;
329 }
330 
331 
332 void
333 DWARFCompileUnit::Dump(Stream *s) const
334 {
335     s->Printf("0x%8.8x: Compile Unit: length = 0x%8.8x, version = 0x%4.4x, abbr_offset = 0x%8.8x, addr_size = 0x%2.2x (next CU at {0x%8.8x})\n",
336                 m_offset, m_length, m_version, GetAbbrevOffset(), m_addr_size, GetNextCompileUnitOffset());
337 }
338 
339 
340 static uint8_t g_default_addr_size = 4;
341 
342 uint8_t
343 DWARFCompileUnit::GetAddressByteSize(const DWARFCompileUnit* cu)
344 {
345     if (cu)
346         return cu->GetAddressByteSize();
347     return DWARFCompileUnit::GetDefaultAddressSize();
348 }
349 
350 uint8_t
351 DWARFCompileUnit::GetDefaultAddressSize()
352 {
353     return g_default_addr_size;
354 }
355 
356 void
357 DWARFCompileUnit::SetDefaultAddressSize(uint8_t addr_size)
358 {
359     g_default_addr_size = addr_size;
360 }
361 
362 void
363 DWARFCompileUnit::BuildAddressRangeTable (SymbolFileDWARF* dwarf2Data,
364                                           DWARFDebugAranges* debug_aranges)
365 {
366     // This function is usually called if there in no .debug_aranges section
367     // in order to produce a compile unit level set of address ranges that
368     // is accurate.
369 
370     // First get the compile unit DIE only and check if it has a DW_AT_ranges
371     const DWARFDebugInfoEntry* die = GetCompileUnitDIEOnly();
372 
373     const dw_offset_t cu_offset = GetOffset();
374     if (die)
375     {
376         DWARFDebugRanges::RangeList ranges;
377         const size_t num_ranges = die->GetAttributeAddressRanges(dwarf2Data, this, ranges, false);
378         if (num_ranges > 0)
379         {
380             // This compile unit has DW_AT_ranges, assume this is correct if it
381             // is present since clang no longer makes .debug_aranges by default
382             // and it emits DW_AT_ranges for DW_TAG_compile_units. GCC also does
383             // this with recent GCC builds.
384             for (size_t i=0; i<num_ranges; ++i)
385             {
386                 const DWARFDebugRanges::RangeList::Entry &range = ranges.GetEntryRef(i);
387                 debug_aranges->AppendRange(cu_offset, range.GetRangeBase(), range.GetRangeEnd());
388             }
389 
390             return; // We got all of our ranges from the DW_AT_ranges attribute
391         }
392     }
393     // We don't have a DW_AT_ranges attribute, so we need to parse the DWARF
394 
395     // If the DIEs weren't parsed, then we don't want all dies for all compile units
396     // to stay loaded when they weren't needed. So we can end up parsing the DWARF
397     // and then throwing them all away to keep memory usage down.
398     const bool clear_dies = ExtractDIEsIfNeeded (false) > 1;
399 
400     die = DIE();
401     if (die)
402         die->BuildAddressRangeTable(dwarf2Data, this, debug_aranges);
403 
404     if (debug_aranges->IsEmpty())
405     {
406         // We got nothing from the functions, maybe we have a line tables only
407         // situation. Check the line tables and build the arange table from this.
408         SymbolContext sc;
409         sc.comp_unit = dwarf2Data->GetCompUnitForDWARFCompUnit(this);
410         if (sc.comp_unit)
411         {
412             SymbolFileDWARFDebugMap *debug_map_sym_file = m_dwarf2Data->GetDebugMapSymfile();
413             if (debug_map_sym_file == NULL)
414             {
415                 LineTable *line_table = sc.comp_unit->GetLineTable();
416 
417                 if (line_table)
418                 {
419                     LineTable::FileAddressRanges file_ranges;
420                     const bool append = true;
421                     const size_t num_ranges = line_table->GetContiguousFileAddressRanges (file_ranges, append);
422                     for (uint32_t idx=0; idx<num_ranges; ++idx)
423                     {
424                         const LineTable::FileAddressRanges::Entry &range = file_ranges.GetEntryRef(idx);
425                         debug_aranges->AppendRange(cu_offset, range.GetRangeBase(), range.GetRangeEnd());
426                         printf ("0x%8.8x: [0x%16.16" PRIx64 " - 0x%16.16" PRIx64 ")\n", GetOffset(), range.GetRangeBase(), range.GetRangeEnd());
427                     }
428                 }
429             }
430             else
431                 debug_map_sym_file->AddOSOARanges(dwarf2Data,debug_aranges);
432         }
433     }
434 
435     // Keep memory down by clearing DIEs if this generate function
436     // caused them to be parsed
437     if (clear_dies)
438         ClearDIEs (true);
439 
440 }
441 
442 
443 const DWARFDebugAranges &
444 DWARFCompileUnit::GetFunctionAranges ()
445 {
446     if (m_func_aranges_ap.get() == NULL)
447     {
448         m_func_aranges_ap.reset (new DWARFDebugAranges());
449         Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_ARANGES));
450 
451         if (log)
452         {
453             m_dwarf2Data->GetObjectFile()->GetModule()->LogMessage (log,
454                                                                     "DWARFCompileUnit::GetFunctionAranges() for compile unit at .debug_info[0x%8.8x]",
455                                                                     GetOffset());
456         }
457         const DWARFDebugInfoEntry* die = DIE();
458         if (die)
459             die->BuildFunctionAddressRangeTable (m_dwarf2Data, this, m_func_aranges_ap.get());
460         const bool minimize = false;
461         m_func_aranges_ap->Sort(minimize);
462     }
463     return *m_func_aranges_ap.get();
464 }
465 
466 bool
467 DWARFCompileUnit::LookupAddress
468 (
469     const dw_addr_t address,
470     DWARFDebugInfoEntry** function_die_handle,
471     DWARFDebugInfoEntry** block_die_handle
472 )
473 {
474     bool success = false;
475 
476     if (function_die_handle != NULL && DIE())
477     {
478 
479         const DWARFDebugAranges &func_aranges = GetFunctionAranges ();
480 
481         // Re-check the aranges auto pointer contents in case it was created above
482         if (!func_aranges.IsEmpty())
483         {
484             *function_die_handle = GetDIEPtr(func_aranges.FindAddress(address));
485             if (*function_die_handle != NULL)
486             {
487                 success = true;
488                 if (block_die_handle != NULL)
489                 {
490                     DWARFDebugInfoEntry* child = (*function_die_handle)->GetFirstChild();
491                     while (child)
492                     {
493                         if (child->LookupAddress(address, m_dwarf2Data, this, NULL, block_die_handle))
494                             break;
495                         child = child->GetSibling();
496                     }
497                 }
498             }
499         }
500     }
501     return success;
502 }
503 
504 //----------------------------------------------------------------------
505 // Compare function DWARFDebugAranges::Range structures
506 //----------------------------------------------------------------------
507 static bool CompareDIEOffset (const DWARFDebugInfoEntry& die1, const DWARFDebugInfoEntry& die2)
508 {
509     return die1.GetOffset() < die2.GetOffset();
510 }
511 
512 //----------------------------------------------------------------------
513 // GetDIEPtr()
514 //
515 // Get the DIE (Debug Information Entry) with the specified offset.
516 //----------------------------------------------------------------------
517 DWARFDebugInfoEntry*
518 DWARFCompileUnit::GetDIEPtr(dw_offset_t die_offset)
519 {
520     if (die_offset != DW_INVALID_OFFSET)
521     {
522         ExtractDIEsIfNeeded (false);
523         DWARFDebugInfoEntry compare_die;
524         compare_die.SetOffset(die_offset);
525         DWARFDebugInfoEntry::iterator end = m_die_array.end();
526         DWARFDebugInfoEntry::iterator pos = lower_bound(m_die_array.begin(), end, compare_die, CompareDIEOffset);
527         if (pos != end)
528         {
529             if (die_offset == (*pos).GetOffset())
530                 return &(*pos);
531         }
532     }
533     return NULL;    // Not found in any compile units
534 }
535 
536 //----------------------------------------------------------------------
537 // GetDIEPtrContainingOffset()
538 //
539 // Get the DIE (Debug Information Entry) that contains the specified
540 // .debug_info offset.
541 //----------------------------------------------------------------------
542 const DWARFDebugInfoEntry*
543 DWARFCompileUnit::GetDIEPtrContainingOffset(dw_offset_t die_offset)
544 {
545     if (die_offset != DW_INVALID_OFFSET)
546     {
547         ExtractDIEsIfNeeded (false);
548         DWARFDebugInfoEntry compare_die;
549         compare_die.SetOffset(die_offset);
550         DWARFDebugInfoEntry::iterator end = m_die_array.end();
551         DWARFDebugInfoEntry::iterator pos = lower_bound(m_die_array.begin(), end, compare_die, CompareDIEOffset);
552         if (pos != end)
553         {
554             if (die_offset >= (*pos).GetOffset())
555             {
556                 DWARFDebugInfoEntry::iterator next = pos + 1;
557                 if (next != end)
558                 {
559                     if (die_offset < (*next).GetOffset())
560                         return &(*pos);
561                 }
562             }
563         }
564     }
565     return NULL;    // Not found in any compile units
566 }
567 
568 
569 
570 size_t
571 DWARFCompileUnit::AppendDIEsWithTag (const dw_tag_t tag, DWARFDIECollection& dies, uint32_t depth) const
572 {
573     size_t old_size = dies.Size();
574     DWARFDebugInfoEntry::const_iterator pos;
575     DWARFDebugInfoEntry::const_iterator end = m_die_array.end();
576     for (pos = m_die_array.begin(); pos != end; ++pos)
577     {
578         if (pos->Tag() == tag)
579             dies.Append (&(*pos));
580     }
581 
582     // Return the number of DIEs added to the collection
583     return dies.Size() - old_size;
584 }
585 
586 //void
587 //DWARFCompileUnit::AddGlobalDIEByIndex (uint32_t die_idx)
588 //{
589 //    m_global_die_indexes.push_back (die_idx);
590 //}
591 //
592 //
593 //void
594 //DWARFCompileUnit::AddGlobal (const DWARFDebugInfoEntry* die)
595 //{
596 //    // Indexes to all file level global and static variables
597 //    m_global_die_indexes;
598 //
599 //    if (m_die_array.empty())
600 //        return;
601 //
602 //    const DWARFDebugInfoEntry* first_die = &m_die_array[0];
603 //    const DWARFDebugInfoEntry* end = first_die + m_die_array.size();
604 //    if (first_die <= die && die < end)
605 //        m_global_die_indexes.push_back (die - first_die);
606 //}
607 
608 
609 void
610 DWARFCompileUnit::Index (const uint32_t cu_idx,
611                          NameToDIE& func_basenames,
612                          NameToDIE& func_fullnames,
613                          NameToDIE& func_methods,
614                          NameToDIE& func_selectors,
615                          NameToDIE& objc_class_selectors,
616                          NameToDIE& globals,
617                          NameToDIE& types,
618                          NameToDIE& namespaces)
619 {
620     const DWARFDataExtractor* debug_str = &m_dwarf2Data->get_debug_str_data();
621 
622     const uint8_t *fixed_form_sizes = DWARFFormValue::GetFixedFormSizesForAddressSize (GetAddressByteSize());
623 
624     Log *log (LogChannelDWARF::GetLogIfAll (DWARF_LOG_LOOKUPS));
625 
626     if (log)
627     {
628         m_dwarf2Data->GetObjectFile()->GetModule()->LogMessage (log,
629                                                                 "DWARFCompileUnit::Index() for compile unit at .debug_info[0x%8.8x]",
630                                                                 GetOffset());
631     }
632 
633     DWARFDebugInfoEntry::const_iterator pos;
634     DWARFDebugInfoEntry::const_iterator begin = m_die_array.begin();
635     DWARFDebugInfoEntry::const_iterator end = m_die_array.end();
636     for (pos = begin; pos != end; ++pos)
637     {
638         const DWARFDebugInfoEntry &die = *pos;
639 
640         const dw_tag_t tag = die.Tag();
641 
642         switch (tag)
643         {
644         case DW_TAG_subprogram:
645         case DW_TAG_inlined_subroutine:
646         case DW_TAG_base_type:
647         case DW_TAG_class_type:
648         case DW_TAG_constant:
649         case DW_TAG_enumeration_type:
650         case DW_TAG_string_type:
651         case DW_TAG_subroutine_type:
652         case DW_TAG_structure_type:
653         case DW_TAG_union_type:
654         case DW_TAG_typedef:
655         case DW_TAG_namespace:
656         case DW_TAG_variable:
657         case DW_TAG_unspecified_type:
658             break;
659 
660         default:
661             continue;
662         }
663 
664         DWARFDebugInfoEntry::Attributes attributes;
665         const char *name = NULL;
666         const char *mangled_cstr = NULL;
667         bool is_declaration = false;
668         //bool is_artificial = false;
669         bool has_address = false;
670         bool has_location = false;
671         bool is_global_or_static_variable = false;
672 
673         dw_offset_t specification_die_offset = DW_INVALID_OFFSET;
674         const size_t num_attributes = die.GetAttributes(m_dwarf2Data, this, fixed_form_sizes, attributes);
675         if (num_attributes > 0)
676         {
677             for (uint32_t i=0; i<num_attributes; ++i)
678             {
679                 dw_attr_t attr = attributes.AttributeAtIndex(i);
680                 DWARFFormValue form_value;
681                 switch (attr)
682                 {
683                 case DW_AT_name:
684                     if (attributes.ExtractFormValueAtIndex(m_dwarf2Data, i, form_value))
685                         name = form_value.AsCString(debug_str);
686                     break;
687 
688                 case DW_AT_declaration:
689                     if (attributes.ExtractFormValueAtIndex(m_dwarf2Data, i, form_value))
690                         is_declaration = form_value.Unsigned() != 0;
691                     break;
692 
693 //                case DW_AT_artificial:
694 //                    if (attributes.ExtractFormValueAtIndex(m_dwarf2Data, i, form_value))
695 //                        is_artificial = form_value.Unsigned() != 0;
696 //                    break;
697 
698                 case DW_AT_MIPS_linkage_name:
699                 case DW_AT_linkage_name:
700                     if (attributes.ExtractFormValueAtIndex(m_dwarf2Data, i, form_value))
701                         mangled_cstr = form_value.AsCString(debug_str);
702                     break;
703 
704                 case DW_AT_low_pc:
705                 case DW_AT_high_pc:
706                 case DW_AT_ranges:
707                     has_address = true;
708                     break;
709 
710                 case DW_AT_entry_pc:
711                     has_address = true;
712                     break;
713 
714                 case DW_AT_location:
715                     has_location = true;
716                     if (tag == DW_TAG_variable)
717                     {
718                         const DWARFDebugInfoEntry* parent_die = die.GetParent();
719                         while ( parent_die != NULL )
720                         {
721                             switch (parent_die->Tag())
722                             {
723                             case DW_TAG_subprogram:
724                             case DW_TAG_lexical_block:
725                             case DW_TAG_inlined_subroutine:
726                                 // Even if this is a function level static, we don't add it. We could theoretically
727                                 // add these if we wanted to by introspecting into the DW_AT_location and seeing
728                                 // if the location describes a hard coded address, but we dont want the performance
729                                 // penalty of that right now.
730                                 is_global_or_static_variable = false;
731 //                              if (attributes.ExtractFormValueAtIndex(dwarf2Data, i, form_value))
732 //                              {
733 //                                  // If we have valid block data, then we have location expression bytes
734 //                                  // that are fixed (not a location list).
735 //                                  const uint8_t *block_data = form_value.BlockData();
736 //                                  if (block_data)
737 //                                  {
738 //                                      uint32_t block_length = form_value.Unsigned();
739 //                                      if (block_length == 1 + attributes.CompileUnitAtIndex(i)->GetAddressByteSize())
740 //                                      {
741 //                                          if (block_data[0] == DW_OP_addr)
742 //                                              add_die = true;
743 //                                      }
744 //                                  }
745 //                              }
746                                 parent_die = NULL;  // Terminate the while loop.
747                                 break;
748 
749                             case DW_TAG_compile_unit:
750                                 is_global_or_static_variable = true;
751                                 parent_die = NULL;  // Terminate the while loop.
752                                 break;
753 
754                             default:
755                                 parent_die = parent_die->GetParent();   // Keep going in the while loop.
756                                 break;
757                             }
758                         }
759                     }
760                     break;
761 
762                 case DW_AT_specification:
763                     if (attributes.ExtractFormValueAtIndex(m_dwarf2Data, i, form_value))
764                         specification_die_offset = form_value.Reference(this);
765                     break;
766                 }
767             }
768         }
769 
770         switch (tag)
771         {
772         case DW_TAG_subprogram:
773             if (has_address)
774             {
775                 if (name)
776                 {
777                     // Note, this check is also done in ParseMethodName, but since this is a hot loop, we do the
778                     // simple inlined check outside the call.
779                     ObjCLanguageRuntime::MethodName objc_method(name, true);
780                     if (objc_method.IsValid(true))
781                     {
782                         ConstString objc_class_name_with_category (objc_method.GetClassNameWithCategory());
783                         ConstString objc_selector_name (objc_method.GetSelector());
784                         ConstString objc_fullname_no_category_name (objc_method.GetFullNameWithoutCategory(true));
785                         ConstString objc_class_name_no_category (objc_method.GetClassName());
786                         func_fullnames.Insert (ConstString(name), die.GetOffset());
787                         if (objc_class_name_with_category)
788                             objc_class_selectors.Insert(objc_class_name_with_category, die.GetOffset());
789                         if (objc_class_name_no_category && objc_class_name_no_category != objc_class_name_with_category)
790                             objc_class_selectors.Insert(objc_class_name_no_category, die.GetOffset());
791                         if (objc_selector_name)
792                             func_selectors.Insert (objc_selector_name, die.GetOffset());
793                         if (objc_fullname_no_category_name)
794                             func_fullnames.Insert (objc_fullname_no_category_name, die.GetOffset());
795                     }
796                     // If we have a mangled name, then the DW_AT_name attribute
797                     // is usually the method name without the class or any parameters
798                     const DWARFDebugInfoEntry *parent = die.GetParent();
799                     bool is_method = false;
800                     if (parent)
801                     {
802                         dw_tag_t parent_tag = parent->Tag();
803                         if (parent_tag == DW_TAG_class_type || parent_tag == DW_TAG_structure_type)
804                         {
805                             is_method = true;
806                         }
807                         else
808                         {
809                             if (specification_die_offset != DW_INVALID_OFFSET)
810                             {
811                                 const DWARFDebugInfoEntry *specification_die = m_dwarf2Data->DebugInfo()->GetDIEPtr (specification_die_offset, NULL);
812                                 if (specification_die)
813                                 {
814                                     parent = specification_die->GetParent();
815                                     if (parent)
816                                     {
817                                         parent_tag = parent->Tag();
818 
819                                         if (parent_tag == DW_TAG_class_type || parent_tag == DW_TAG_structure_type)
820                                             is_method = true;
821                                     }
822                                 }
823                             }
824                         }
825                     }
826 
827 
828                     if (is_method)
829                         func_methods.Insert (ConstString(name), die.GetOffset());
830                     else
831                         func_basenames.Insert (ConstString(name), die.GetOffset());
832 
833                     if (!is_method && !mangled_cstr && !objc_method.IsValid(true))
834                         func_fullnames.Insert (ConstString(name), die.GetOffset());
835                 }
836                 if (mangled_cstr)
837                 {
838                     // Make sure our mangled name isn't the same string table entry
839                     // as our name. If it starts with '_', then it is ok, else compare
840                     // the string to make sure it isn't the same and we don't end up
841                     // with duplicate entries
842                     if (name != mangled_cstr && ((mangled_cstr[0] == '_') || (name && ::strcmp(name, mangled_cstr) != 0)))
843                     {
844                         Mangled mangled (ConstString(mangled_cstr), true);
845                         func_fullnames.Insert (mangled.GetMangledName(), die.GetOffset());
846                         if (mangled.GetDemangledName())
847                             func_fullnames.Insert (mangled.GetDemangledName(), die.GetOffset());
848                     }
849                 }
850             }
851             break;
852 
853         case DW_TAG_inlined_subroutine:
854             if (has_address)
855             {
856                 if (name)
857                     func_basenames.Insert (ConstString(name), die.GetOffset());
858                 if (mangled_cstr)
859                 {
860                     // Make sure our mangled name isn't the same string table entry
861                     // as our name. If it starts with '_', then it is ok, else compare
862                     // the string to make sure it isn't the same and we don't end up
863                     // with duplicate entries
864                     if (name != mangled_cstr && ((mangled_cstr[0] == '_') || (::strcmp(name, mangled_cstr) != 0)))
865                     {
866                         Mangled mangled (ConstString(mangled_cstr), true);
867                         func_fullnames.Insert (mangled.GetMangledName(), die.GetOffset());
868                         if (mangled.GetDemangledName())
869                             func_fullnames.Insert (mangled.GetDemangledName(), die.GetOffset());
870                     }
871                 }
872                 else
873                     func_fullnames.Insert (ConstString(name), die.GetOffset());
874             }
875             break;
876 
877         case DW_TAG_base_type:
878         case DW_TAG_class_type:
879         case DW_TAG_constant:
880         case DW_TAG_enumeration_type:
881         case DW_TAG_string_type:
882         case DW_TAG_subroutine_type:
883         case DW_TAG_structure_type:
884         case DW_TAG_union_type:
885         case DW_TAG_typedef:
886         case DW_TAG_unspecified_type:
887             if (name && is_declaration == false)
888             {
889                 types.Insert (ConstString(name), die.GetOffset());
890             }
891             break;
892 
893         case DW_TAG_namespace:
894             if (name)
895                 namespaces.Insert (ConstString(name), die.GetOffset());
896             break;
897 
898         case DW_TAG_variable:
899             if (name && has_location && is_global_or_static_variable)
900             {
901                 globals.Insert (ConstString(name), die.GetOffset());
902                 // Be sure to include variables by their mangled and demangled
903                 // names if they have any since a variable can have a basename
904                 // "i", a mangled named "_ZN12_GLOBAL__N_11iE" and a demangled
905                 // mangled name "(anonymous namespace)::i"...
906 
907                 // Make sure our mangled name isn't the same string table entry
908                 // as our name. If it starts with '_', then it is ok, else compare
909                 // the string to make sure it isn't the same and we don't end up
910                 // with duplicate entries
911                 if (mangled_cstr && name != mangled_cstr && ((mangled_cstr[0] == '_') || (::strcmp(name, mangled_cstr) != 0)))
912                 {
913                     Mangled mangled (ConstString(mangled_cstr), true);
914                     globals.Insert (mangled.GetMangledName(), die.GetOffset());
915                     if (mangled.GetDemangledName())
916                         globals.Insert (mangled.GetDemangledName(), die.GetOffset());
917                 }
918             }
919             break;
920 
921         default:
922             continue;
923         }
924     }
925 }
926 
927 bool
928 DWARFCompileUnit::Supports_unnamed_objc_bitfields ()
929 {
930     if (GetProducer() == eProducerClang)
931     {
932         const uint32_t major_version = GetProducerVersionMajor();
933         if (major_version > 425 || (major_version == 425 && GetProducerVersionUpdate() >= 13))
934             return true;
935         else
936             return false;
937     }
938     return true; // Assume all other compilers didn't have incorrect ObjC bitfield info
939 }
940 
941 bool
942 DWARFCompileUnit::Supports_DW_AT_APPLE_objc_complete_type ()
943 {
944     if (GetProducer() == eProducerLLVMGCC)
945         return false;
946     return true;
947 }
948 
949 bool
950 DWARFCompileUnit::DW_AT_decl_file_attributes_are_invalid()
951 {
952     // llvm-gcc makes completely invalid decl file attributes and won't ever
953     // be fixed, so we need to know to ignore these.
954     return GetProducer() == eProducerLLVMGCC;
955 }
956 
957 void
958 DWARFCompileUnit::ParseProducerInfo ()
959 {
960     m_producer_version_major = UINT32_MAX;
961     m_producer_version_minor = UINT32_MAX;
962     m_producer_version_update = UINT32_MAX;
963 
964     const DWARFDebugInfoEntry *die = GetCompileUnitDIEOnly();
965     if (die)
966     {
967 
968         const char *producer_cstr = die->GetAttributeValueAsString(m_dwarf2Data, this, DW_AT_producer, NULL);
969         if (producer_cstr)
970         {
971             RegularExpression llvm_gcc_regex("^4\\.[012]\\.[01] \\(Based on Apple Inc\\. build [0-9]+\\) \\(LLVM build [\\.0-9]+\\)$");
972             if (llvm_gcc_regex.Execute (producer_cstr))
973             {
974                 m_producer = eProducerLLVMGCC;
975             }
976             else if (strstr(producer_cstr, "clang"))
977             {
978                 static RegularExpression g_clang_version_regex("clang-([0-9]+)\\.([0-9]+)\\.([0-9]+)");
979                 RegularExpression::Match regex_match(3);
980                 if (g_clang_version_regex.Execute (producer_cstr, &regex_match))
981                 {
982                     std::string str;
983                     if (regex_match.GetMatchAtIndex (producer_cstr, 1, str))
984                         m_producer_version_major = Args::StringToUInt32(str.c_str(), UINT32_MAX, 10);
985                     if (regex_match.GetMatchAtIndex (producer_cstr, 2, str))
986                         m_producer_version_minor = Args::StringToUInt32(str.c_str(), UINT32_MAX, 10);
987                     if (regex_match.GetMatchAtIndex (producer_cstr, 3, str))
988                         m_producer_version_update = Args::StringToUInt32(str.c_str(), UINT32_MAX, 10);
989                 }
990                 m_producer = eProducerClang;
991             }
992             else if (strstr(producer_cstr, "GNU"))
993                 m_producer = eProducerGCC;
994         }
995     }
996     if (m_producer == eProducerInvalid)
997         m_producer = eProcucerOther;
998 }
999 
1000 DWARFCompileUnit::Producer
1001 DWARFCompileUnit::GetProducer ()
1002 {
1003     if (m_producer == eProducerInvalid)
1004         ParseProducerInfo ();
1005     return m_producer;
1006 }
1007 
1008 
1009 uint32_t
1010 DWARFCompileUnit::GetProducerVersionMajor()
1011 {
1012     if (m_producer_version_major == 0)
1013         ParseProducerInfo ();
1014     return m_producer_version_major;
1015 }
1016 
1017 uint32_t
1018 DWARFCompileUnit::GetProducerVersionMinor()
1019 {
1020     if (m_producer_version_minor == 0)
1021         ParseProducerInfo ();
1022     return m_producer_version_minor;
1023 }
1024 
1025 uint32_t
1026 DWARFCompileUnit::GetProducerVersionUpdate()
1027 {
1028     if (m_producer_version_update == 0)
1029         ParseProducerInfo ();
1030     return m_producer_version_update;
1031 }
1032 
1033