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 <cassert>
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 lldb_private::dwarf;
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(%s 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(),
221       llvm::dwarf::FormEncodingString(value.Form()).str().c_str(),
222       value.Unsigned(), toString(expected_ranges.takeError()).c_str());
223   return DWARFRangeList();
224 }
225 
226 // GetDIENamesAndRanges
227 //
228 // Gets the valid address ranges for a given DIE by looking for a
229 // DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.
230 bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
231     DWARFUnit *cu, const char *&name, const char *&mangled,
232     DWARFRangeList &ranges, int &decl_file, int &decl_line, int &decl_column,
233     int &call_file, int &call_line, int &call_column,
234     DWARFExpressionList *frame_base) const {
235   dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
236   dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
237   std::vector<DWARFDIE> dies;
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 =
348                   DWARFExpressionList(module,
349                                       DWARFExpression(DataExtractor(
350                                           data, block_offset, block_length)),
351                                       cu);
352             } else {
353               DataExtractor data = cu->GetLocationData();
354               const dw_offset_t offset = form_value.Unsigned();
355               if (data.ValidOffset(offset)) {
356                 data = DataExtractor(data, offset, data.GetByteSize() - offset);
357                 DWARFExpression::ParseDWARFLocationList(cu, data, frame_base);
358               }
359             }
360           }
361           break;
362 
363         default:
364           break;
365         }
366       }
367     }
368   }
369 
370   if (ranges.IsEmpty()) {
371     if (lo_pc != LLDB_INVALID_ADDRESS) {
372       if (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc)
373         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
374       else
375         ranges.Append(DWARFRangeList::Entry(lo_pc, 0));
376     }
377   }
378 
379   if (ranges.IsEmpty() || name == nullptr || mangled == nullptr) {
380     for (const DWARFDIE &die : dies) {
381       if (die) {
382         die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,
383                                            decl_file, decl_line, decl_column,
384                                            call_file, call_line, call_column);
385       }
386     }
387   }
388   return !ranges.IsEmpty();
389 }
390 
391 // Get all attribute values for a given DIE, including following any
392 // specification or abstract origin attributes and including those in the
393 // results. Any duplicate attributes will have the first instance take
394 // precedence (this can happen for declaration attributes).
395 size_t DWARFDebugInfoEntry::GetAttributes(DWARFUnit *cu,
396                                           DWARFAttributes &attributes,
397                                           Recurse recurse,
398                                           uint32_t curr_depth) const {
399   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
400   if (abbrevDecl) {
401     const DWARFDataExtractor &data = cu->GetData();
402     lldb::offset_t offset = GetFirstAttributeOffset();
403 
404     const uint32_t num_attributes = abbrevDecl->NumAttributes();
405     for (uint32_t i = 0; i < num_attributes; ++i) {
406       DWARFFormValue form_value(cu);
407       dw_attr_t attr;
408       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
409       const dw_form_t form = form_value.Form();
410 
411       // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
412       // attributes, the depth will be non-zero. We need to omit certain
413       // attributes that don't make sense.
414       switch (attr) {
415       case DW_AT_sibling:
416       case DW_AT_declaration:
417         if (curr_depth > 0) {
418           // This attribute doesn't make sense when combined with the DIE that
419           // references this DIE. We know a DIE is referencing this DIE because
420           // curr_depth is not zero
421           break;
422         }
423         LLVM_FALLTHROUGH;
424       default:
425         attributes.Append(form_value, offset, attr);
426         break;
427       }
428 
429       if (recurse == Recurse::yes &&
430           ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin))) {
431         if (form_value.ExtractValue(data, &offset)) {
432           DWARFDIE spec_die = form_value.Reference();
433           if (spec_die)
434             spec_die.GetDIE()->GetAttributes(spec_die.GetCU(), attributes,
435                                              recurse, curr_depth + 1);
436         }
437       } else {
438         llvm::Optional<uint8_t> fixed_skip_size = DWARFFormValue::GetFixedSize(form, cu);
439         if (fixed_skip_size)
440           offset += *fixed_skip_size;
441         else
442           DWARFFormValue::SkipValue(form, data, &offset, cu);
443       }
444     }
445   } else {
446     attributes.Clear();
447   }
448   return attributes.Size();
449 }
450 
451 // GetAttributeValue
452 //
453 // Get the value of an attribute and return the .debug_info or .debug_types
454 // offset of the attribute if it was properly extracted into form_value,
455 // or zero if we fail since an offset of zero is invalid for an attribute (it
456 // would be a compile unit header).
457 dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
458     const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
459     dw_offset_t *end_attr_offset_ptr,
460     bool check_specification_or_abstract_origin) const {
461   if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
462     uint32_t attr_idx = abbrevDecl->FindAttributeIndex(attr);
463 
464     if (attr_idx != DW_INVALID_INDEX) {
465       const DWARFDataExtractor &data = cu->GetData();
466       lldb::offset_t offset = GetFirstAttributeOffset();
467 
468       uint32_t idx = 0;
469       while (idx < attr_idx)
470         DWARFFormValue::SkipValue(abbrevDecl->GetFormByIndex(idx++),
471                                   data, &offset, cu);
472 
473       const dw_offset_t attr_offset = offset;
474       form_value.SetUnit(cu);
475       form_value.SetForm(abbrevDecl->GetFormByIndex(idx));
476       if (form_value.ExtractValue(data, &offset)) {
477         if (end_attr_offset_ptr)
478           *end_attr_offset_ptr = offset;
479         return attr_offset;
480       }
481     }
482   }
483 
484   if (check_specification_or_abstract_origin) {
485     if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
486       DWARFDIE die = form_value.Reference();
487       if (die) {
488         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
489             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
490         if (die_offset)
491           return die_offset;
492       }
493     }
494 
495     if (GetAttributeValue(cu, DW_AT_abstract_origin, 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   return 0;
506 }
507 
508 // GetAttributeValueAsString
509 //
510 // Get the value of an attribute as a string return it. The resulting pointer
511 // to the string data exists within the supplied SymbolFileDWARF and will only
512 // be available as long as the SymbolFileDWARF is still around and it's content
513 // doesn't change.
514 const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
515     const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
516     bool check_specification_or_abstract_origin) const {
517   DWARFFormValue form_value;
518   if (GetAttributeValue(cu, attr, form_value, nullptr,
519                         check_specification_or_abstract_origin))
520     return form_value.AsCString();
521   return fail_value;
522 }
523 
524 // GetAttributeValueAsUnsigned
525 //
526 // Get the value of an attribute as unsigned and return it.
527 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
528     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
529     bool check_specification_or_abstract_origin) const {
530   DWARFFormValue form_value;
531   if (GetAttributeValue(cu, attr, form_value, nullptr,
532                         check_specification_or_abstract_origin))
533     return form_value.Unsigned();
534   return fail_value;
535 }
536 
537 // GetAttributeValueAsReference
538 //
539 // Get the value of an attribute as reference and fix up and compile unit
540 // relative offsets as needed.
541 DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
542     const DWARFUnit *cu, const dw_attr_t attr,
543     bool check_specification_or_abstract_origin) const {
544   DWARFFormValue form_value;
545   if (GetAttributeValue(cu, attr, form_value, nullptr,
546                         check_specification_or_abstract_origin))
547     return form_value.Reference();
548   return {};
549 }
550 
551 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
552     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
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.Address();
558   return fail_value;
559 }
560 
561 // GetAttributeHighPC
562 //
563 // Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
564 // pc>.
565 //
566 // Returns the hi_pc or fail_value.
567 dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
568     const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
569     bool check_specification_or_abstract_origin) const {
570   DWARFFormValue form_value;
571   if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
572                         check_specification_or_abstract_origin)) {
573     dw_form_t form = form_value.Form();
574     if (form == DW_FORM_addr || form == DW_FORM_addrx ||
575         form == DW_FORM_GNU_addr_index)
576       return form_value.Address();
577 
578     // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
579     return lo_pc + form_value.Unsigned();
580   }
581   return fail_value;
582 }
583 
584 // GetAttributeAddressRange
585 //
586 // Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
587 // from-low-pc>.
588 //
589 // Returns true or sets lo_pc and hi_pc to fail_value.
590 bool DWARFDebugInfoEntry::GetAttributeAddressRange(
591     const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
592     uint64_t fail_value, bool check_specification_or_abstract_origin) const {
593   lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
594                                      check_specification_or_abstract_origin);
595   if (lo_pc != fail_value) {
596     hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
597                                check_specification_or_abstract_origin);
598     if (hi_pc != fail_value)
599       return true;
600   }
601   lo_pc = fail_value;
602   hi_pc = fail_value;
603   return false;
604 }
605 
606 size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
607     DWARFUnit *cu, DWARFRangeList &ranges, bool check_hi_lo_pc,
608     bool check_specification_or_abstract_origin) const {
609   ranges.Clear();
610 
611   DWARFFormValue form_value;
612   if (GetAttributeValue(cu, DW_AT_ranges, form_value)) {
613     ranges = GetRangesOrReportError(*cu, *this, form_value);
614   } else if (check_hi_lo_pc) {
615     dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
616     dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
617     if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
618                                  check_specification_or_abstract_origin)) {
619       if (lo_pc < hi_pc)
620         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
621     }
622   }
623   return ranges.GetSize();
624 }
625 
626 // GetName
627 //
628 // Get value of the DW_AT_name attribute and return it if one exists, else
629 // return NULL.
630 const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
631   return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
632 }
633 
634 // GetMangledName
635 //
636 // Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
637 // exists, else return the value of the DW_AT_name attribute
638 const char *
639 DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
640                                     bool substitute_name_allowed) const {
641   const char *name = nullptr;
642 
643   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
644   if (name)
645     return name;
646 
647   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
648   if (name)
649     return name;
650 
651   if (!substitute_name_allowed)
652     return nullptr;
653 
654   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
655   return name;
656 }
657 
658 // GetPubname
659 //
660 // Get value the name for a DIE as it should appear for a .debug_pubnames or
661 // .debug_pubtypes section.
662 const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
663   const char *name = nullptr;
664   if (!cu)
665     return name;
666 
667   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
668   if (name)
669     return name;
670 
671   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
672   if (name)
673     return name;
674 
675   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
676   return name;
677 }
678 
679 /// This function is builds a table very similar to the standard .debug_aranges
680 /// table, except that the actual DIE offset for the function is placed in the
681 /// table instead of the compile unit offset.
682 void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
683     DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
684   if (m_tag) {
685     if (m_tag == DW_TAG_subprogram) {
686       DWARFRangeList ranges;
687       GetAttributeAddressRanges(cu, ranges,
688                                 /*check_hi_lo_pc=*/true);
689       for (const auto &r : ranges) {
690         debug_aranges->AppendRange(GetOffset(), r.GetRangeBase(),
691                                    r.GetRangeEnd());
692       }
693     }
694 
695     const DWARFDebugInfoEntry *child = GetFirstChild();
696     while (child) {
697       child->BuildFunctionAddressRangeTable(cu, debug_aranges);
698       child = child->GetSibling();
699     }
700   }
701 }
702 
703 DWARFDeclContext
704 DWARFDebugInfoEntry::GetDWARFDeclContextStatic(const DWARFDebugInfoEntry *die,
705                                                DWARFUnit *cu) {
706   DWARFDeclContext dwarf_decl_ctx;
707   for (;;) {
708     const dw_tag_t tag = die->Tag();
709     if (tag == DW_TAG_compile_unit || tag == DW_TAG_partial_unit)
710       return dwarf_decl_ctx;
711     dwarf_decl_ctx.AppendDeclContext(tag, die->GetName(cu));
712     DWARFDIE parent_decl_ctx_die = die->GetParentDeclContextDIE(cu);
713     if (!parent_decl_ctx_die || parent_decl_ctx_die.GetDIE() == die)
714       return dwarf_decl_ctx;
715     if (parent_decl_ctx_die.Tag() == DW_TAG_compile_unit ||
716         parent_decl_ctx_die.Tag() == DW_TAG_partial_unit)
717       return dwarf_decl_ctx;
718     die = parent_decl_ctx_die.GetDIE();
719     cu = parent_decl_ctx_die.GetCU();
720   }
721 }
722 
723 DWARFDeclContext DWARFDebugInfoEntry::GetDWARFDeclContext(DWARFUnit *cu) const {
724   return GetDWARFDeclContextStatic(this, cu);
725 }
726 
727 DWARFDIE
728 DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
729   DWARFAttributes attributes;
730   GetAttributes(cu, attributes, Recurse::yes);
731   return GetParentDeclContextDIE(cu, attributes);
732 }
733 
734 DWARFDIE
735 DWARFDebugInfoEntry::GetParentDeclContextDIE(
736     DWARFUnit *cu, const DWARFAttributes &attributes) const {
737   DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
738 
739   while (die) {
740     // If this is the original DIE that we are searching for a declaration for,
741     // then don't look in the cache as we don't want our own decl context to be
742     // our decl context...
743     if (die.GetDIE() != this) {
744       switch (die.Tag()) {
745       case DW_TAG_compile_unit:
746       case DW_TAG_partial_unit:
747       case DW_TAG_namespace:
748       case DW_TAG_structure_type:
749       case DW_TAG_union_type:
750       case DW_TAG_class_type:
751         return die;
752 
753       default:
754         break;
755       }
756     }
757 
758     DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
759     if (spec_die) {
760       DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
761       if (decl_ctx_die)
762         return decl_ctx_die;
763     }
764 
765     DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
766     if (abs_die) {
767       DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
768       if (decl_ctx_die)
769         return decl_ctx_die;
770     }
771 
772     die = die.GetParent();
773   }
774   return DWARFDIE();
775 }
776 
777 const char *DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
778                                                   std::string &storage) const {
779   DWARFAttributes attributes;
780   GetAttributes(cu, attributes, Recurse::yes);
781   return GetQualifiedName(cu, attributes, storage);
782 }
783 
784 const char *
785 DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
786                                       const DWARFAttributes &attributes,
787                                       std::string &storage) const {
788 
789   const char *name = GetName(cu);
790 
791   if (name) {
792     DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
793     storage.clear();
794     // TODO: change this to get the correct decl context parent....
795     while (parent_decl_ctx_die) {
796       const dw_tag_t parent_tag = parent_decl_ctx_die.Tag();
797       switch (parent_tag) {
798       case DW_TAG_namespace: {
799         const char *namespace_name = parent_decl_ctx_die.GetName();
800         if (namespace_name) {
801           storage.insert(0, "::");
802           storage.insert(0, namespace_name);
803         } else {
804           storage.insert(0, "(anonymous namespace)::");
805         }
806         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
807       } break;
808 
809       case DW_TAG_class_type:
810       case DW_TAG_structure_type:
811       case DW_TAG_union_type: {
812         const char *class_union_struct_name = parent_decl_ctx_die.GetName();
813 
814         if (class_union_struct_name) {
815           storage.insert(0, "::");
816           storage.insert(0, class_union_struct_name);
817         }
818         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
819       } break;
820 
821       default:
822         parent_decl_ctx_die.Clear();
823         break;
824       }
825     }
826 
827     if (storage.empty())
828       storage.append("::");
829 
830     storage.append(name);
831   }
832   if (storage.empty())
833     return nullptr;
834   return storage.c_str();
835 }
836 
837 lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
838   return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
839 }
840 
841 const DWARFAbbreviationDeclaration *
842 DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
843   if (cu) {
844     const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
845     if (abbrev_set)
846       return abbrev_set->GetAbbreviationDeclaration(m_abbr_idx);
847   }
848   return nullptr;
849 }
850 
851 bool DWARFDebugInfoEntry::IsGlobalOrStaticScopeVariable() const {
852   if (Tag() != DW_TAG_variable)
853     return false;
854   const DWARFDebugInfoEntry *parent_die = GetParent();
855   while (parent_die != nullptr) {
856     switch (parent_die->Tag()) {
857     case DW_TAG_subprogram:
858     case DW_TAG_lexical_block:
859     case DW_TAG_inlined_subroutine:
860       return false;
861 
862     case DW_TAG_compile_unit:
863     case DW_TAG_partial_unit:
864       return true;
865 
866     default:
867       break;
868     }
869     parent_die = parent_die->GetParent();
870   }
871   return false;
872 }
873 
874 bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
875   return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
876          m_sibling_idx == rhs.m_sibling_idx &&
877          m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
878          m_tag == rhs.m_tag;
879 }
880 
881 bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
882   return !(*this == rhs);
883 }
884