1 //===-- DWARFDebugInfoEntry.cpp -------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "DWARFDebugInfoEntry.h"
10 
11 #include <assert.h>
12 
13 #include <algorithm>
14 
15 #include "llvm/Support/LEB128.h"
16 
17 #include "lldb/Core/Module.h"
18 #include "lldb/Expression/DWARFExpression.h"
19 #include "lldb/Symbol/ObjectFile.h"
20 #include "lldb/Utility/Stream.h"
21 
22 #include "DWARFCompileUnit.h"
23 #include "DWARFDebugAbbrev.h"
24 #include "DWARFDebugAranges.h"
25 #include "DWARFDebugInfo.h"
26 #include "DWARFDebugRanges.h"
27 #include "DWARFDeclContext.h"
28 #include "DWARFFormValue.h"
29 #include "DWARFUnit.h"
30 #include "SymbolFileDWARF.h"
31 #include "SymbolFileDWARFDwo.h"
32 
33 using namespace lldb_private;
34 using namespace std;
35 extern int g_verbose;
36 
37 // Extract a debug info entry for a given DWARFUnit from the data
38 // starting at the offset in offset_ptr
39 bool DWARFDebugInfoEntry::Extract(const DWARFDataExtractor &data,
40                                   const DWARFUnit *cu,
41                                   lldb::offset_t *offset_ptr) {
42   m_offset = *offset_ptr;
43   m_parent_idx = 0;
44   m_sibling_idx = 0;
45   const uint64_t abbr_idx = data.GetULEB128(offset_ptr);
46   lldbassert(abbr_idx <= UINT16_MAX);
47   m_abbr_idx = abbr_idx;
48 
49   // assert (fixed_form_sizes);  // For best performance this should be
50   // specified!
51 
52   if (m_abbr_idx == 0) {
53     m_tag = llvm::dwarf::DW_TAG_null;
54     m_has_children = false;
55     return true; // NULL debug tag entry
56   }
57 
58   lldb::offset_t offset = *offset_ptr;
59   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
60   if (abbrevDecl == nullptr) {
61     cu->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
62         "{0x%8.8x}: invalid abbreviation code %u, please file a bug and "
63         "attach the file at the start of this error message",
64         m_offset, (unsigned)abbr_idx);
65     // WE can't parse anymore if the DWARF is borked...
66     *offset_ptr = UINT32_MAX;
67     return false;
68   }
69   m_tag = abbrevDecl->Tag();
70   m_has_children = abbrevDecl->HasChildren();
71   // Skip all data in the .debug_info or .debug_types for the attributes
72   const uint32_t numAttributes = abbrevDecl->NumAttributes();
73   uint32_t i;
74   dw_form_t form;
75   for (i = 0; i < numAttributes; ++i) {
76     form = abbrevDecl->GetFormByIndexUnchecked(i);
77     llvm::Optional<uint8_t> fixed_skip_size =
78         DWARFFormValue::GetFixedSize(form, cu);
79     if (fixed_skip_size)
80       offset += *fixed_skip_size;
81     else {
82       bool form_is_indirect = false;
83       do {
84         form_is_indirect = false;
85         uint32_t form_size = 0;
86         switch (form) {
87         // Blocks if inlined data that have a length field and the data bytes
88         // inlined in the .debug_info/.debug_types
89         case DW_FORM_exprloc:
90         case DW_FORM_block:
91           form_size = data.GetULEB128(&offset);
92           break;
93         case DW_FORM_block1:
94           form_size = data.GetU8_unchecked(&offset);
95           break;
96         case DW_FORM_block2:
97           form_size = data.GetU16_unchecked(&offset);
98           break;
99         case DW_FORM_block4:
100           form_size = data.GetU32_unchecked(&offset);
101           break;
102 
103         // Inlined NULL terminated C-strings
104         case DW_FORM_string:
105           data.GetCStr(&offset);
106           break;
107 
108         // Compile unit address sized values
109         case DW_FORM_addr:
110           form_size = cu->GetAddressByteSize();
111           break;
112         case DW_FORM_ref_addr:
113           if (cu->GetVersion() <= 2)
114             form_size = cu->GetAddressByteSize();
115           else
116             form_size = 4;
117           break;
118 
119         // 0 sized form
120         case DW_FORM_flag_present:
121           form_size = 0;
122           break;
123 
124         // 1 byte values
125         case DW_FORM_addrx1:
126         case DW_FORM_data1:
127         case DW_FORM_flag:
128         case DW_FORM_ref1:
129         case DW_FORM_strx1:
130           form_size = 1;
131           break;
132 
133         // 2 byte values
134         case DW_FORM_addrx2:
135         case DW_FORM_data2:
136         case DW_FORM_ref2:
137         case DW_FORM_strx2:
138           form_size = 2;
139           break;
140 
141         // 3 byte values
142         case DW_FORM_addrx3:
143         case DW_FORM_strx3:
144           form_size = 3;
145           break;
146 
147         // 4 byte values
148         case DW_FORM_addrx4:
149         case DW_FORM_data4:
150         case DW_FORM_ref4:
151         case DW_FORM_strx4:
152           form_size = 4;
153           break;
154 
155         // 8 byte values
156         case DW_FORM_data8:
157         case DW_FORM_ref8:
158         case DW_FORM_ref_sig8:
159           form_size = 8;
160           break;
161 
162         // signed or unsigned LEB 128 values
163         case DW_FORM_addrx:
164         case DW_FORM_loclistx:
165         case DW_FORM_rnglistx:
166         case DW_FORM_sdata:
167         case DW_FORM_udata:
168         case DW_FORM_ref_udata:
169         case DW_FORM_GNU_addr_index:
170         case DW_FORM_GNU_str_index:
171         case DW_FORM_strx:
172           data.Skip_LEB128(&offset);
173           break;
174 
175         case DW_FORM_indirect:
176           form_is_indirect = true;
177           form = data.GetULEB128(&offset);
178           break;
179 
180         case DW_FORM_strp:
181         case DW_FORM_line_strp:
182         case DW_FORM_sec_offset:
183           data.GetU32(&offset);
184           break;
185 
186         case DW_FORM_implicit_const:
187           form_size = 0;
188           break;
189 
190         default:
191           cu->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
192               "{0x%8.8x}: Unsupported DW_FORM_0x%x, please file a bug and "
193               "attach the file at the start of this error message",
194               m_offset, (unsigned)form);
195           *offset_ptr = m_offset;
196           return false;
197         }
198         offset += form_size;
199 
200       } while (form_is_indirect);
201     }
202   }
203   *offset_ptr = offset;
204   return true;
205 }
206 
207 static DWARFRangeList GetRangesOrReportError(DWARFUnit &unit,
208                                              const DWARFDebugInfoEntry &die,
209                                              const DWARFFormValue &value) {
210   llvm::Expected<DWARFRangeList> expected_ranges =
211       (value.Form() == DW_FORM_rnglistx)
212           ? unit.FindRnglistFromIndex(value.Unsigned())
213           : unit.FindRnglistFromOffset(value.Unsigned());
214   if (expected_ranges)
215     return std::move(*expected_ranges);
216   unit.GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
217       "{0x%8.8x}: DIE has DW_AT_ranges(0x%" PRIx64 ") attribute, but "
218       "range extraction failed (%s), please file a bug "
219       "and attach the file at the start of this error message",
220       die.GetOffset(), value.Unsigned(),
221       toString(expected_ranges.takeError()).c_str());
222   return DWARFRangeList();
223 }
224 
225 // GetDIENamesAndRanges
226 //
227 // Gets the valid address ranges for a given DIE by looking for a
228 // DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.
229 bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
230     DWARFUnit *cu, const char *&name, const char *&mangled,
231     DWARFRangeList &ranges, int &decl_file, int &decl_line, int &decl_column,
232     int &call_file, int &call_line, int &call_column,
233     DWARFExpression *frame_base) const {
234   dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
235   dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
236   std::vector<DWARFDIE> dies;
237   bool set_frame_base_loclist_addr = false;
238 
239   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
240 
241   SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
242   lldb::ModuleSP module = dwarf.GetObjectFile()->GetModule();
243 
244   if (abbrevDecl) {
245     const DWARFDataExtractor &data = cu->GetData();
246     lldb::offset_t offset = GetFirstAttributeOffset();
247 
248     if (!data.ValidOffset(offset))
249       return false;
250 
251     const uint32_t numAttributes = abbrevDecl->NumAttributes();
252     bool do_offset = false;
253 
254     for (uint32_t i = 0; i < numAttributes; ++i) {
255       DWARFFormValue form_value(cu);
256       dw_attr_t attr;
257       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
258 
259       if (form_value.ExtractValue(data, &offset)) {
260         switch (attr) {
261         case DW_AT_low_pc:
262           lo_pc = form_value.Address();
263 
264           if (do_offset)
265             hi_pc += lo_pc;
266           do_offset = false;
267           break;
268 
269         case DW_AT_entry_pc:
270           lo_pc = form_value.Address();
271           break;
272 
273         case DW_AT_high_pc:
274           if (form_value.Form() == DW_FORM_addr ||
275               form_value.Form() == DW_FORM_addrx ||
276               form_value.Form() == DW_FORM_GNU_addr_index) {
277             hi_pc = form_value.Address();
278           } else {
279             hi_pc = form_value.Unsigned();
280             if (lo_pc == LLDB_INVALID_ADDRESS)
281               do_offset = hi_pc != LLDB_INVALID_ADDRESS;
282             else
283               hi_pc += lo_pc; // DWARF 4 introduces <offset-from-lo-pc> to save
284                               // on relocations
285           }
286           break;
287 
288         case DW_AT_ranges:
289           ranges = GetRangesOrReportError(*cu, *this, form_value);
290           break;
291 
292         case DW_AT_name:
293           if (name == nullptr)
294             name = form_value.AsCString();
295           break;
296 
297         case DW_AT_MIPS_linkage_name:
298         case DW_AT_linkage_name:
299           if (mangled == nullptr)
300             mangled = form_value.AsCString();
301           break;
302 
303         case DW_AT_abstract_origin:
304           dies.push_back(form_value.Reference());
305           break;
306 
307         case DW_AT_specification:
308           dies.push_back(form_value.Reference());
309           break;
310 
311         case DW_AT_decl_file:
312           if (decl_file == 0)
313             decl_file = form_value.Unsigned();
314           break;
315 
316         case DW_AT_decl_line:
317           if (decl_line == 0)
318             decl_line = form_value.Unsigned();
319           break;
320 
321         case DW_AT_decl_column:
322           if (decl_column == 0)
323             decl_column = form_value.Unsigned();
324           break;
325 
326         case DW_AT_call_file:
327           if (call_file == 0)
328             call_file = form_value.Unsigned();
329           break;
330 
331         case DW_AT_call_line:
332           if (call_line == 0)
333             call_line = form_value.Unsigned();
334           break;
335 
336         case DW_AT_call_column:
337           if (call_column == 0)
338             call_column = form_value.Unsigned();
339           break;
340 
341         case DW_AT_frame_base:
342           if (frame_base) {
343             if (form_value.BlockData()) {
344               uint32_t block_offset =
345                   form_value.BlockData() - data.GetDataStart();
346               uint32_t block_length = form_value.Unsigned();
347               *frame_base = DWARFExpression(
348                   module, DataExtractor(data, block_offset, block_length), cu);
349             } else {
350               DataExtractor data = cu->GetLocationData();
351               const dw_offset_t offset = form_value.Unsigned();
352               if (data.ValidOffset(offset)) {
353                 data = DataExtractor(data, offset, data.GetByteSize() - offset);
354                 *frame_base = DWARFExpression(module, data, cu);
355                 if (lo_pc != LLDB_INVALID_ADDRESS) {
356                   assert(lo_pc >= cu->GetBaseAddress());
357                   frame_base->SetLocationListAddresses(cu->GetBaseAddress(),
358                                                        lo_pc);
359                 } else {
360                   set_frame_base_loclist_addr = true;
361                 }
362               }
363             }
364           }
365           break;
366 
367         default:
368           break;
369         }
370       }
371     }
372   }
373 
374   if (ranges.IsEmpty()) {
375     if (lo_pc != LLDB_INVALID_ADDRESS) {
376       if (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc)
377         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
378       else
379         ranges.Append(DWARFRangeList::Entry(lo_pc, 0));
380     }
381   }
382 
383   if (set_frame_base_loclist_addr) {
384     dw_addr_t lowest_range_pc = ranges.GetMinRangeBase(0);
385     assert(lowest_range_pc >= cu->GetBaseAddress());
386     frame_base->SetLocationListAddresses(cu->GetBaseAddress(), lowest_range_pc);
387   }
388 
389   if (ranges.IsEmpty() || name == nullptr || mangled == nullptr) {
390     for (const DWARFDIE &die : dies) {
391       if (die) {
392         die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,
393                                            decl_file, decl_line, decl_column,
394                                            call_file, call_line, call_column);
395       }
396     }
397   }
398   return !ranges.IsEmpty();
399 }
400 
401 // Get all attribute values for a given DIE, including following any
402 // specification or abstract origin attributes and including those in the
403 // results. Any duplicate attributes will have the first instance take
404 // precedence (this can happen for declaration attributes).
405 size_t DWARFDebugInfoEntry::GetAttributes(DWARFUnit *cu,
406                                           DWARFAttributes &attributes,
407                                           Recurse recurse,
408                                           uint32_t curr_depth) const {
409   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
410   if (abbrevDecl) {
411     const DWARFDataExtractor &data = cu->GetData();
412     lldb::offset_t offset = GetFirstAttributeOffset();
413 
414     const uint32_t num_attributes = abbrevDecl->NumAttributes();
415     for (uint32_t i = 0; i < num_attributes; ++i) {
416       DWARFFormValue form_value(cu);
417       dw_attr_t attr;
418       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
419       const dw_form_t form = form_value.Form();
420 
421       // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
422       // attributes, the depth will be non-zero. We need to omit certain
423       // attributes that don't make sense.
424       switch (attr) {
425       case DW_AT_sibling:
426       case DW_AT_declaration:
427         if (curr_depth > 0) {
428           // This attribute doesn't make sense when combined with the DIE that
429           // references this DIE. We know a DIE is referencing this DIE because
430           // curr_depth is not zero
431           break;
432         }
433         LLVM_FALLTHROUGH;
434       default:
435         attributes.Append(form_value, offset, attr);
436         break;
437       }
438 
439       if (recurse == Recurse::yes &&
440           ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin))) {
441         if (form_value.ExtractValue(data, &offset)) {
442           DWARFDIE spec_die = form_value.Reference();
443           if (spec_die)
444             spec_die.GetDIE()->GetAttributes(spec_die.GetCU(), attributes,
445                                              recurse, curr_depth + 1);
446         }
447       } else {
448         llvm::Optional<uint8_t> fixed_skip_size = DWARFFormValue::GetFixedSize(form, cu);
449         if (fixed_skip_size)
450           offset += *fixed_skip_size;
451         else
452           DWARFFormValue::SkipValue(form, data, &offset, cu);
453       }
454     }
455   } else {
456     attributes.Clear();
457   }
458   return attributes.Size();
459 }
460 
461 // GetAttributeValue
462 //
463 // Get the value of an attribute and return the .debug_info or .debug_types
464 // offset of the attribute if it was properly extracted into form_value,
465 // or zero if we fail since an offset of zero is invalid for an attribute (it
466 // would be a compile unit header).
467 dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
468     const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
469     dw_offset_t *end_attr_offset_ptr,
470     bool check_specification_or_abstract_origin) const {
471   if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
472     uint32_t attr_idx = abbrevDecl->FindAttributeIndex(attr);
473 
474     if (attr_idx != DW_INVALID_INDEX) {
475       const DWARFDataExtractor &data = cu->GetData();
476       lldb::offset_t offset = GetFirstAttributeOffset();
477 
478       uint32_t idx = 0;
479       while (idx < attr_idx)
480         DWARFFormValue::SkipValue(abbrevDecl->GetFormByIndex(idx++),
481                                   data, &offset, cu);
482 
483       const dw_offset_t attr_offset = offset;
484       form_value.SetUnit(cu);
485       form_value.SetForm(abbrevDecl->GetFormByIndex(idx));
486       if (form_value.ExtractValue(data, &offset)) {
487         if (end_attr_offset_ptr)
488           *end_attr_offset_ptr = offset;
489         return attr_offset;
490       }
491     }
492   }
493 
494   if (check_specification_or_abstract_origin) {
495     if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
496       DWARFDIE die = form_value.Reference();
497       if (die) {
498         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
499             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
500         if (die_offset)
501           return die_offset;
502       }
503     }
504 
505     if (GetAttributeValue(cu, DW_AT_abstract_origin, form_value)) {
506       DWARFDIE die = form_value.Reference();
507       if (die) {
508         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
509             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
510         if (die_offset)
511           return die_offset;
512       }
513     }
514   }
515   return 0;
516 }
517 
518 // GetAttributeValueAsString
519 //
520 // Get the value of an attribute as a string return it. The resulting pointer
521 // to the string data exists within the supplied SymbolFileDWARF and will only
522 // be available as long as the SymbolFileDWARF is still around and it's content
523 // doesn't change.
524 const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
525     const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
526     bool check_specification_or_abstract_origin) const {
527   DWARFFormValue form_value;
528   if (GetAttributeValue(cu, attr, form_value, nullptr,
529                         check_specification_or_abstract_origin))
530     return form_value.AsCString();
531   return fail_value;
532 }
533 
534 // GetAttributeValueAsUnsigned
535 //
536 // Get the value of an attribute as unsigned and return it.
537 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
538     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
539     bool check_specification_or_abstract_origin) const {
540   DWARFFormValue form_value;
541   if (GetAttributeValue(cu, attr, form_value, nullptr,
542                         check_specification_or_abstract_origin))
543     return form_value.Unsigned();
544   return fail_value;
545 }
546 
547 // GetAttributeValueAsReference
548 //
549 // Get the value of an attribute as reference and fix up and compile unit
550 // relative offsets as needed.
551 DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
552     const DWARFUnit *cu, const dw_attr_t attr,
553     bool check_specification_or_abstract_origin) const {
554   DWARFFormValue form_value;
555   if (GetAttributeValue(cu, attr, form_value, nullptr,
556                         check_specification_or_abstract_origin))
557     return form_value.Reference();
558   return {};
559 }
560 
561 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
562     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
563     bool check_specification_or_abstract_origin) const {
564   DWARFFormValue form_value;
565   if (GetAttributeValue(cu, attr, form_value, nullptr,
566                         check_specification_or_abstract_origin))
567     return form_value.Address();
568   return fail_value;
569 }
570 
571 // GetAttributeHighPC
572 //
573 // Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
574 // pc>.
575 //
576 // Returns the hi_pc or fail_value.
577 dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
578     const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
579     bool check_specification_or_abstract_origin) const {
580   DWARFFormValue form_value;
581   if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
582                         check_specification_or_abstract_origin)) {
583     dw_form_t form = form_value.Form();
584     if (form == DW_FORM_addr || form == DW_FORM_addrx ||
585         form == DW_FORM_GNU_addr_index)
586       return form_value.Address();
587 
588     // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
589     return lo_pc + form_value.Unsigned();
590   }
591   return fail_value;
592 }
593 
594 // GetAttributeAddressRange
595 //
596 // Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
597 // from-low-pc>.
598 //
599 // Returns true or sets lo_pc and hi_pc to fail_value.
600 bool DWARFDebugInfoEntry::GetAttributeAddressRange(
601     const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
602     uint64_t fail_value, bool check_specification_or_abstract_origin) const {
603   lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
604                                      check_specification_or_abstract_origin);
605   if (lo_pc != fail_value) {
606     hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
607                                check_specification_or_abstract_origin);
608     if (hi_pc != fail_value)
609       return true;
610   }
611   lo_pc = fail_value;
612   hi_pc = fail_value;
613   return false;
614 }
615 
616 size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
617     DWARFUnit *cu, DWARFRangeList &ranges, bool check_hi_lo_pc,
618     bool check_specification_or_abstract_origin) const {
619   ranges.Clear();
620 
621   DWARFFormValue form_value;
622   if (GetAttributeValue(cu, DW_AT_ranges, form_value)) {
623     ranges = GetRangesOrReportError(*cu, *this, form_value);
624   } else if (check_hi_lo_pc) {
625     dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
626     dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
627     if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
628                                  check_specification_or_abstract_origin)) {
629       if (lo_pc < hi_pc)
630         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
631     }
632   }
633   return ranges.GetSize();
634 }
635 
636 // GetName
637 //
638 // Get value of the DW_AT_name attribute and return it if one exists, else
639 // return NULL.
640 const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
641   return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
642 }
643 
644 // GetMangledName
645 //
646 // Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
647 // exists, else return the value of the DW_AT_name attribute
648 const char *
649 DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
650                                     bool substitute_name_allowed) const {
651   const char *name = nullptr;
652 
653   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
654   if (name)
655     return name;
656 
657   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
658   if (name)
659     return name;
660 
661   if (!substitute_name_allowed)
662     return nullptr;
663 
664   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
665   return name;
666 }
667 
668 // GetPubname
669 //
670 // Get value the name for a DIE as it should appear for a .debug_pubnames or
671 // .debug_pubtypes section.
672 const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
673   const char *name = nullptr;
674   if (!cu)
675     return name;
676 
677   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
678   if (name)
679     return name;
680 
681   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
682   if (name)
683     return name;
684 
685   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
686   return name;
687 }
688 
689 /// This function is builds a table very similar to the standard .debug_aranges
690 /// table, except that the actual DIE offset for the function is placed in the
691 /// table instead of the compile unit offset.
692 void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
693     DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
694   if (m_tag) {
695     if (m_tag == DW_TAG_subprogram) {
696       DWARFRangeList ranges;
697       GetAttributeAddressRanges(cu, ranges,
698                                 /*check_hi_lo_pc=*/true);
699       for (const auto &r : ranges) {
700         debug_aranges->AppendRange(GetOffset(), r.GetRangeBase(),
701                                    r.GetRangeEnd());
702       }
703     }
704 
705     const DWARFDebugInfoEntry *child = GetFirstChild();
706     while (child) {
707       child->BuildFunctionAddressRangeTable(cu, debug_aranges);
708       child = child->GetSibling();
709     }
710   }
711 }
712 
713 DWARFDeclContext
714 DWARFDebugInfoEntry::GetDWARFDeclContextStatic(const DWARFDebugInfoEntry *die,
715                                                DWARFUnit *cu) {
716   DWARFDeclContext dwarf_decl_ctx;
717   for (;;) {
718     const dw_tag_t tag = die->Tag();
719     if (tag == DW_TAG_compile_unit || tag == DW_TAG_partial_unit)
720       return dwarf_decl_ctx;
721     dwarf_decl_ctx.AppendDeclContext(tag, die->GetName(cu));
722     DWARFDIE parent_decl_ctx_die = die->GetParentDeclContextDIE(cu);
723     if (!parent_decl_ctx_die || parent_decl_ctx_die.GetDIE() == die)
724       return dwarf_decl_ctx;
725     if (parent_decl_ctx_die.Tag() == DW_TAG_compile_unit ||
726         parent_decl_ctx_die.Tag() == DW_TAG_partial_unit)
727       return dwarf_decl_ctx;
728     die = parent_decl_ctx_die.GetDIE();
729     cu = parent_decl_ctx_die.GetCU();
730   }
731 }
732 
733 DWARFDeclContext DWARFDebugInfoEntry::GetDWARFDeclContext(DWARFUnit *cu) const {
734   return GetDWARFDeclContextStatic(this, cu);
735 }
736 
737 DWARFDIE
738 DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
739   DWARFAttributes attributes;
740   GetAttributes(cu, attributes, Recurse::yes);
741   return GetParentDeclContextDIE(cu, attributes);
742 }
743 
744 DWARFDIE
745 DWARFDebugInfoEntry::GetParentDeclContextDIE(
746     DWARFUnit *cu, const DWARFAttributes &attributes) const {
747   DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
748 
749   while (die) {
750     // If this is the original DIE that we are searching for a declaration for,
751     // then don't look in the cache as we don't want our own decl context to be
752     // our decl context...
753     if (die.GetDIE() != this) {
754       switch (die.Tag()) {
755       case DW_TAG_compile_unit:
756       case DW_TAG_partial_unit:
757       case DW_TAG_namespace:
758       case DW_TAG_structure_type:
759       case DW_TAG_union_type:
760       case DW_TAG_class_type:
761         return die;
762 
763       default:
764         break;
765       }
766     }
767 
768     DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
769     if (spec_die) {
770       DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
771       if (decl_ctx_die)
772         return decl_ctx_die;
773     }
774 
775     DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
776     if (abs_die) {
777       DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
778       if (decl_ctx_die)
779         return decl_ctx_die;
780     }
781 
782     die = die.GetParent();
783   }
784   return DWARFDIE();
785 }
786 
787 const char *DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
788                                                   std::string &storage) const {
789   DWARFAttributes attributes;
790   GetAttributes(cu, attributes, Recurse::yes);
791   return GetQualifiedName(cu, attributes, storage);
792 }
793 
794 const char *
795 DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
796                                       const DWARFAttributes &attributes,
797                                       std::string &storage) const {
798 
799   const char *name = GetName(cu);
800 
801   if (name) {
802     DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
803     storage.clear();
804     // TODO: change this to get the correct decl context parent....
805     while (parent_decl_ctx_die) {
806       const dw_tag_t parent_tag = parent_decl_ctx_die.Tag();
807       switch (parent_tag) {
808       case DW_TAG_namespace: {
809         const char *namespace_name = parent_decl_ctx_die.GetName();
810         if (namespace_name) {
811           storage.insert(0, "::");
812           storage.insert(0, namespace_name);
813         } else {
814           storage.insert(0, "(anonymous namespace)::");
815         }
816         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
817       } break;
818 
819       case DW_TAG_class_type:
820       case DW_TAG_structure_type:
821       case DW_TAG_union_type: {
822         const char *class_union_struct_name = parent_decl_ctx_die.GetName();
823 
824         if (class_union_struct_name) {
825           storage.insert(0, "::");
826           storage.insert(0, class_union_struct_name);
827         }
828         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
829       } break;
830 
831       default:
832         parent_decl_ctx_die.Clear();
833         break;
834       }
835     }
836 
837     if (storage.empty())
838       storage.append("::");
839 
840     storage.append(name);
841   }
842   if (storage.empty())
843     return nullptr;
844   return storage.c_str();
845 }
846 
847 lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
848   return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
849 }
850 
851 const DWARFAbbreviationDeclaration *
852 DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
853   if (cu) {
854     const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
855     if (abbrev_set)
856       return abbrev_set->GetAbbreviationDeclaration(m_abbr_idx);
857   }
858   return nullptr;
859 }
860 
861 bool DWARFDebugInfoEntry::IsGlobalOrStaticScopeVariable() const {
862   if (Tag() != DW_TAG_variable)
863     return false;
864   const DWARFDebugInfoEntry *parent_die = GetParent();
865   while (parent_die != nullptr) {
866     switch (parent_die->Tag()) {
867     case DW_TAG_subprogram:
868     case DW_TAG_lexical_block:
869     case DW_TAG_inlined_subroutine:
870       return false;
871 
872     case DW_TAG_compile_unit:
873     case DW_TAG_partial_unit:
874       return true;
875 
876     default:
877       break;
878     }
879     parent_die = parent_die->GetParent();
880   }
881   return false;
882 }
883 
884 bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
885   return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
886          m_sibling_idx == rhs.m_sibling_idx &&
887          m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
888          m_tag == rhs.m_tag;
889 }
890 
891 bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
892   return !(*this == rhs);
893 }
894