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   bool set_frame_base_loclist_addr = false;
239 
240   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
241 
242   SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
243   lldb::ModuleSP module = dwarf.GetObjectFile()->GetModule();
244 
245   if (abbrevDecl) {
246     const DWARFDataExtractor &data = cu->GetData();
247     lldb::offset_t offset = GetFirstAttributeOffset();
248 
249     if (!data.ValidOffset(offset))
250       return false;
251 
252     const uint32_t numAttributes = abbrevDecl->NumAttributes();
253     bool do_offset = false;
254 
255     for (uint32_t i = 0; i < numAttributes; ++i) {
256       DWARFFormValue form_value(cu);
257       dw_attr_t attr;
258       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
259 
260       if (form_value.ExtractValue(data, &offset)) {
261         switch (attr) {
262         case DW_AT_low_pc:
263           lo_pc = form_value.Address();
264 
265           if (do_offset)
266             hi_pc += lo_pc;
267           do_offset = false;
268           break;
269 
270         case DW_AT_entry_pc:
271           lo_pc = form_value.Address();
272           break;
273 
274         case DW_AT_high_pc:
275           if (form_value.Form() == DW_FORM_addr ||
276               form_value.Form() == DW_FORM_addrx ||
277               form_value.Form() == DW_FORM_GNU_addr_index) {
278             hi_pc = form_value.Address();
279           } else {
280             hi_pc = form_value.Unsigned();
281             if (lo_pc == LLDB_INVALID_ADDRESS)
282               do_offset = hi_pc != LLDB_INVALID_ADDRESS;
283             else
284               hi_pc += lo_pc; // DWARF 4 introduces <offset-from-lo-pc> to save
285                               // on relocations
286           }
287           break;
288 
289         case DW_AT_ranges:
290           ranges = GetRangesOrReportError(*cu, *this, form_value);
291           break;
292 
293         case DW_AT_name:
294           if (name == nullptr)
295             name = form_value.AsCString();
296           break;
297 
298         case DW_AT_MIPS_linkage_name:
299         case DW_AT_linkage_name:
300           if (mangled == nullptr)
301             mangled = form_value.AsCString();
302           break;
303 
304         case DW_AT_abstract_origin:
305           dies.push_back(form_value.Reference());
306           break;
307 
308         case DW_AT_specification:
309           dies.push_back(form_value.Reference());
310           break;
311 
312         case DW_AT_decl_file:
313           if (decl_file == 0)
314             decl_file = form_value.Unsigned();
315           break;
316 
317         case DW_AT_decl_line:
318           if (decl_line == 0)
319             decl_line = form_value.Unsigned();
320           break;
321 
322         case DW_AT_decl_column:
323           if (decl_column == 0)
324             decl_column = form_value.Unsigned();
325           break;
326 
327         case DW_AT_call_file:
328           if (call_file == 0)
329             call_file = form_value.Unsigned();
330           break;
331 
332         case DW_AT_call_line:
333           if (call_line == 0)
334             call_line = form_value.Unsigned();
335           break;
336 
337         case DW_AT_call_column:
338           if (call_column == 0)
339             call_column = form_value.Unsigned();
340           break;
341 
342         case DW_AT_frame_base:
343           if (frame_base) {
344             if (form_value.BlockData()) {
345               uint32_t block_offset =
346                   form_value.BlockData() - data.GetDataStart();
347               uint32_t block_length = form_value.Unsigned();
348               *frame_base =
349                   DWARFExpressionList(module,
350                                       DWARFExpression(DataExtractor(
351                                           data, block_offset, block_length)),
352                                       cu);
353             } else {
354               DataExtractor data = cu->GetLocationData();
355               const dw_offset_t offset = form_value.Unsigned();
356               if (data.ValidOffset(offset)) {
357                 data = DataExtractor(data, offset, data.GetByteSize() - offset);
358                 if (lo_pc != LLDB_INVALID_ADDRESS) {
359                   assert(lo_pc >= cu->GetBaseAddress());
360                   DWARFExpression::ParseDWARFLocationList(cu, data, frame_base);
361                   frame_base->SetFuncFileAddress(lo_pc);
362                 } else
363                   set_frame_base_loclist_addr = true;
364               }
365             }
366           }
367           break;
368 
369         default:
370           break;
371         }
372       }
373     }
374   }
375 
376   if (ranges.IsEmpty()) {
377     if (lo_pc != LLDB_INVALID_ADDRESS) {
378       if (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc)
379         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
380       else
381         ranges.Append(DWARFRangeList::Entry(lo_pc, 0));
382     }
383   }
384 
385   if (set_frame_base_loclist_addr) {
386     dw_addr_t lowest_range_pc = ranges.GetMinRangeBase(0);
387     assert(lowest_range_pc >= cu->GetBaseAddress());
388     frame_base->SetFuncFileAddress(lowest_range_pc);
389   }
390 
391   if (ranges.IsEmpty() || name == nullptr || mangled == nullptr) {
392     for (const DWARFDIE &die : dies) {
393       if (die) {
394         die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,
395                                            decl_file, decl_line, decl_column,
396                                            call_file, call_line, call_column);
397       }
398     }
399   }
400   return !ranges.IsEmpty();
401 }
402 
403 // Get all attribute values for a given DIE, including following any
404 // specification or abstract origin attributes and including those in the
405 // results. Any duplicate attributes will have the first instance take
406 // precedence (this can happen for declaration attributes).
407 size_t DWARFDebugInfoEntry::GetAttributes(DWARFUnit *cu,
408                                           DWARFAttributes &attributes,
409                                           Recurse recurse,
410                                           uint32_t curr_depth) const {
411   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
412   if (abbrevDecl) {
413     const DWARFDataExtractor &data = cu->GetData();
414     lldb::offset_t offset = GetFirstAttributeOffset();
415 
416     const uint32_t num_attributes = abbrevDecl->NumAttributes();
417     for (uint32_t i = 0; i < num_attributes; ++i) {
418       DWARFFormValue form_value(cu);
419       dw_attr_t attr;
420       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
421       const dw_form_t form = form_value.Form();
422 
423       // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
424       // attributes, the depth will be non-zero. We need to omit certain
425       // attributes that don't make sense.
426       switch (attr) {
427       case DW_AT_sibling:
428       case DW_AT_declaration:
429         if (curr_depth > 0) {
430           // This attribute doesn't make sense when combined with the DIE that
431           // references this DIE. We know a DIE is referencing this DIE because
432           // curr_depth is not zero
433           break;
434         }
435         LLVM_FALLTHROUGH;
436       default:
437         attributes.Append(form_value, offset, attr);
438         break;
439       }
440 
441       if (recurse == Recurse::yes &&
442           ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin))) {
443         if (form_value.ExtractValue(data, &offset)) {
444           DWARFDIE spec_die = form_value.Reference();
445           if (spec_die)
446             spec_die.GetDIE()->GetAttributes(spec_die.GetCU(), attributes,
447                                              recurse, curr_depth + 1);
448         }
449       } else {
450         llvm::Optional<uint8_t> fixed_skip_size = DWARFFormValue::GetFixedSize(form, cu);
451         if (fixed_skip_size)
452           offset += *fixed_skip_size;
453         else
454           DWARFFormValue::SkipValue(form, data, &offset, cu);
455       }
456     }
457   } else {
458     attributes.Clear();
459   }
460   return attributes.Size();
461 }
462 
463 // GetAttributeValue
464 //
465 // Get the value of an attribute and return the .debug_info or .debug_types
466 // offset of the attribute if it was properly extracted into form_value,
467 // or zero if we fail since an offset of zero is invalid for an attribute (it
468 // would be a compile unit header).
469 dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
470     const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
471     dw_offset_t *end_attr_offset_ptr,
472     bool check_specification_or_abstract_origin) const {
473   if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
474     uint32_t attr_idx = abbrevDecl->FindAttributeIndex(attr);
475 
476     if (attr_idx != DW_INVALID_INDEX) {
477       const DWARFDataExtractor &data = cu->GetData();
478       lldb::offset_t offset = GetFirstAttributeOffset();
479 
480       uint32_t idx = 0;
481       while (idx < attr_idx)
482         DWARFFormValue::SkipValue(abbrevDecl->GetFormByIndex(idx++),
483                                   data, &offset, cu);
484 
485       const dw_offset_t attr_offset = offset;
486       form_value.SetUnit(cu);
487       form_value.SetForm(abbrevDecl->GetFormByIndex(idx));
488       if (form_value.ExtractValue(data, &offset)) {
489         if (end_attr_offset_ptr)
490           *end_attr_offset_ptr = offset;
491         return attr_offset;
492       }
493     }
494   }
495 
496   if (check_specification_or_abstract_origin) {
497     if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
498       DWARFDIE die = form_value.Reference();
499       if (die) {
500         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
501             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
502         if (die_offset)
503           return die_offset;
504       }
505     }
506 
507     if (GetAttributeValue(cu, DW_AT_abstract_origin, form_value)) {
508       DWARFDIE die = form_value.Reference();
509       if (die) {
510         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
511             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
512         if (die_offset)
513           return die_offset;
514       }
515     }
516   }
517   return 0;
518 }
519 
520 // GetAttributeValueAsString
521 //
522 // Get the value of an attribute as a string return it. The resulting pointer
523 // to the string data exists within the supplied SymbolFileDWARF and will only
524 // be available as long as the SymbolFileDWARF is still around and it's content
525 // doesn't change.
526 const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
527     const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
528     bool check_specification_or_abstract_origin) const {
529   DWARFFormValue form_value;
530   if (GetAttributeValue(cu, attr, form_value, nullptr,
531                         check_specification_or_abstract_origin))
532     return form_value.AsCString();
533   return fail_value;
534 }
535 
536 // GetAttributeValueAsUnsigned
537 //
538 // Get the value of an attribute as unsigned and return it.
539 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
540     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
541     bool check_specification_or_abstract_origin) const {
542   DWARFFormValue form_value;
543   if (GetAttributeValue(cu, attr, form_value, nullptr,
544                         check_specification_or_abstract_origin))
545     return form_value.Unsigned();
546   return fail_value;
547 }
548 
549 // GetAttributeValueAsReference
550 //
551 // Get the value of an attribute as reference and fix up and compile unit
552 // relative offsets as needed.
553 DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
554     const DWARFUnit *cu, const dw_attr_t attr,
555     bool check_specification_or_abstract_origin) const {
556   DWARFFormValue form_value;
557   if (GetAttributeValue(cu, attr, form_value, nullptr,
558                         check_specification_or_abstract_origin))
559     return form_value.Reference();
560   return {};
561 }
562 
563 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
564     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
565     bool check_specification_or_abstract_origin) const {
566   DWARFFormValue form_value;
567   if (GetAttributeValue(cu, attr, form_value, nullptr,
568                         check_specification_or_abstract_origin))
569     return form_value.Address();
570   return fail_value;
571 }
572 
573 // GetAttributeHighPC
574 //
575 // Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
576 // pc>.
577 //
578 // Returns the hi_pc or fail_value.
579 dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
580     const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
581     bool check_specification_or_abstract_origin) const {
582   DWARFFormValue form_value;
583   if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
584                         check_specification_or_abstract_origin)) {
585     dw_form_t form = form_value.Form();
586     if (form == DW_FORM_addr || form == DW_FORM_addrx ||
587         form == DW_FORM_GNU_addr_index)
588       return form_value.Address();
589 
590     // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
591     return lo_pc + form_value.Unsigned();
592   }
593   return fail_value;
594 }
595 
596 // GetAttributeAddressRange
597 //
598 // Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
599 // from-low-pc>.
600 //
601 // Returns true or sets lo_pc and hi_pc to fail_value.
602 bool DWARFDebugInfoEntry::GetAttributeAddressRange(
603     const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
604     uint64_t fail_value, bool check_specification_or_abstract_origin) const {
605   lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
606                                      check_specification_or_abstract_origin);
607   if (lo_pc != fail_value) {
608     hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
609                                check_specification_or_abstract_origin);
610     if (hi_pc != fail_value)
611       return true;
612   }
613   lo_pc = fail_value;
614   hi_pc = fail_value;
615   return false;
616 }
617 
618 size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
619     DWARFUnit *cu, DWARFRangeList &ranges, bool check_hi_lo_pc,
620     bool check_specification_or_abstract_origin) const {
621   ranges.Clear();
622 
623   DWARFFormValue form_value;
624   if (GetAttributeValue(cu, DW_AT_ranges, form_value)) {
625     ranges = GetRangesOrReportError(*cu, *this, form_value);
626   } else if (check_hi_lo_pc) {
627     dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
628     dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
629     if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
630                                  check_specification_or_abstract_origin)) {
631       if (lo_pc < hi_pc)
632         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
633     }
634   }
635   return ranges.GetSize();
636 }
637 
638 // GetName
639 //
640 // Get value of the DW_AT_name attribute and return it if one exists, else
641 // return NULL.
642 const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
643   return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
644 }
645 
646 // GetMangledName
647 //
648 // Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
649 // exists, else return the value of the DW_AT_name attribute
650 const char *
651 DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
652                                     bool substitute_name_allowed) const {
653   const char *name = nullptr;
654 
655   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
656   if (name)
657     return name;
658 
659   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
660   if (name)
661     return name;
662 
663   if (!substitute_name_allowed)
664     return nullptr;
665 
666   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
667   return name;
668 }
669 
670 // GetPubname
671 //
672 // Get value the name for a DIE as it should appear for a .debug_pubnames or
673 // .debug_pubtypes section.
674 const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
675   const char *name = nullptr;
676   if (!cu)
677     return name;
678 
679   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
680   if (name)
681     return name;
682 
683   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
684   if (name)
685     return name;
686 
687   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
688   return name;
689 }
690 
691 /// This function is builds a table very similar to the standard .debug_aranges
692 /// table, except that the actual DIE offset for the function is placed in the
693 /// table instead of the compile unit offset.
694 void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
695     DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
696   if (m_tag) {
697     if (m_tag == DW_TAG_subprogram) {
698       DWARFRangeList ranges;
699       GetAttributeAddressRanges(cu, ranges,
700                                 /*check_hi_lo_pc=*/true);
701       for (const auto &r : ranges) {
702         debug_aranges->AppendRange(GetOffset(), r.GetRangeBase(),
703                                    r.GetRangeEnd());
704       }
705     }
706 
707     const DWARFDebugInfoEntry *child = GetFirstChild();
708     while (child) {
709       child->BuildFunctionAddressRangeTable(cu, debug_aranges);
710       child = child->GetSibling();
711     }
712   }
713 }
714 
715 DWARFDeclContext
716 DWARFDebugInfoEntry::GetDWARFDeclContextStatic(const DWARFDebugInfoEntry *die,
717                                                DWARFUnit *cu) {
718   DWARFDeclContext dwarf_decl_ctx;
719   for (;;) {
720     const dw_tag_t tag = die->Tag();
721     if (tag == DW_TAG_compile_unit || tag == DW_TAG_partial_unit)
722       return dwarf_decl_ctx;
723     dwarf_decl_ctx.AppendDeclContext(tag, die->GetName(cu));
724     DWARFDIE parent_decl_ctx_die = die->GetParentDeclContextDIE(cu);
725     if (!parent_decl_ctx_die || parent_decl_ctx_die.GetDIE() == die)
726       return dwarf_decl_ctx;
727     if (parent_decl_ctx_die.Tag() == DW_TAG_compile_unit ||
728         parent_decl_ctx_die.Tag() == DW_TAG_partial_unit)
729       return dwarf_decl_ctx;
730     die = parent_decl_ctx_die.GetDIE();
731     cu = parent_decl_ctx_die.GetCU();
732   }
733 }
734 
735 DWARFDeclContext DWARFDebugInfoEntry::GetDWARFDeclContext(DWARFUnit *cu) const {
736   return GetDWARFDeclContextStatic(this, cu);
737 }
738 
739 DWARFDIE
740 DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
741   DWARFAttributes attributes;
742   GetAttributes(cu, attributes, Recurse::yes);
743   return GetParentDeclContextDIE(cu, attributes);
744 }
745 
746 DWARFDIE
747 DWARFDebugInfoEntry::GetParentDeclContextDIE(
748     DWARFUnit *cu, const DWARFAttributes &attributes) const {
749   DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
750 
751   while (die) {
752     // If this is the original DIE that we are searching for a declaration for,
753     // then don't look in the cache as we don't want our own decl context to be
754     // our decl context...
755     if (die.GetDIE() != this) {
756       switch (die.Tag()) {
757       case DW_TAG_compile_unit:
758       case DW_TAG_partial_unit:
759       case DW_TAG_namespace:
760       case DW_TAG_structure_type:
761       case DW_TAG_union_type:
762       case DW_TAG_class_type:
763         return die;
764 
765       default:
766         break;
767       }
768     }
769 
770     DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
771     if (spec_die) {
772       DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
773       if (decl_ctx_die)
774         return decl_ctx_die;
775     }
776 
777     DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
778     if (abs_die) {
779       DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
780       if (decl_ctx_die)
781         return decl_ctx_die;
782     }
783 
784     die = die.GetParent();
785   }
786   return DWARFDIE();
787 }
788 
789 const char *DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
790                                                   std::string &storage) const {
791   DWARFAttributes attributes;
792   GetAttributes(cu, attributes, Recurse::yes);
793   return GetQualifiedName(cu, attributes, storage);
794 }
795 
796 const char *
797 DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
798                                       const DWARFAttributes &attributes,
799                                       std::string &storage) const {
800 
801   const char *name = GetName(cu);
802 
803   if (name) {
804     DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
805     storage.clear();
806     // TODO: change this to get the correct decl context parent....
807     while (parent_decl_ctx_die) {
808       const dw_tag_t parent_tag = parent_decl_ctx_die.Tag();
809       switch (parent_tag) {
810       case DW_TAG_namespace: {
811         const char *namespace_name = parent_decl_ctx_die.GetName();
812         if (namespace_name) {
813           storage.insert(0, "::");
814           storage.insert(0, namespace_name);
815         } else {
816           storage.insert(0, "(anonymous namespace)::");
817         }
818         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
819       } break;
820 
821       case DW_TAG_class_type:
822       case DW_TAG_structure_type:
823       case DW_TAG_union_type: {
824         const char *class_union_struct_name = parent_decl_ctx_die.GetName();
825 
826         if (class_union_struct_name) {
827           storage.insert(0, "::");
828           storage.insert(0, class_union_struct_name);
829         }
830         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
831       } break;
832 
833       default:
834         parent_decl_ctx_die.Clear();
835         break;
836       }
837     }
838 
839     if (storage.empty())
840       storage.append("::");
841 
842     storage.append(name);
843   }
844   if (storage.empty())
845     return nullptr;
846   return storage.c_str();
847 }
848 
849 lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
850   return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
851 }
852 
853 const DWARFAbbreviationDeclaration *
854 DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
855   if (cu) {
856     const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
857     if (abbrev_set)
858       return abbrev_set->GetAbbreviationDeclaration(m_abbr_idx);
859   }
860   return nullptr;
861 }
862 
863 bool DWARFDebugInfoEntry::IsGlobalOrStaticScopeVariable() const {
864   if (Tag() != DW_TAG_variable)
865     return false;
866   const DWARFDebugInfoEntry *parent_die = GetParent();
867   while (parent_die != nullptr) {
868     switch (parent_die->Tag()) {
869     case DW_TAG_subprogram:
870     case DW_TAG_lexical_block:
871     case DW_TAG_inlined_subroutine:
872       return false;
873 
874     case DW_TAG_compile_unit:
875     case DW_TAG_partial_unit:
876       return true;
877 
878     default:
879       break;
880     }
881     parent_die = parent_die->GetParent();
882   }
883   return false;
884 }
885 
886 bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
887   return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
888          m_sibling_idx == rhs.m_sibling_idx &&
889          m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
890          m_tag == rhs.m_tag;
891 }
892 
893 bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
894   return !(*this == rhs);
895 }
896