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#include <optional>
15
16#include "llvm/Support/LEB128.h"
17
18#include "lldb/Core/Module.h"
19#include "lldb/Expression/DWARFExpression.h"
20#include "lldb/Symbol/ObjectFile.h"
21#include "lldb/Utility/Stream.h"
22#include "lldb/Utility/StreamString.h"
23
24#include "DWARFCompileUnit.h"
25#include "DWARFDebugAranges.h"
26#include "DWARFDebugInfo.h"
27#include "DWARFDebugRanges.h"
28#include "DWARFDeclContext.h"
29#include "DWARFFormValue.h"
30#include "DWARFUnit.h"
31#include "SymbolFileDWARF.h"
32#include "SymbolFileDWARFDwo.h"
33
34#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
35
36using namespace lldb_private;
37using namespace lldb_private::dwarf;
38using namespace lldb_private::plugin::dwarf;
39extern int g_verbose;
40
41// Extract a debug info entry for a given DWARFUnit from the data
42// starting at the offset in offset_ptr
43bool DWARFDebugInfoEntry::Extract(const DWARFDataExtractor &data,
44                                  const DWARFUnit *cu,
45                                  lldb::offset_t *offset_ptr) {
46  m_offset = *offset_ptr;
47  m_parent_idx = 0;
48  m_sibling_idx = 0;
49  const uint64_t abbr_idx = data.GetULEB128(offset_ptr);
50  lldbassert(abbr_idx <= UINT16_MAX);
51  m_abbr_idx = abbr_idx;
52
53  if (m_abbr_idx == 0) {
54    m_tag = llvm::dwarf::DW_TAG_null;
55    m_has_children = false;
56    return true; // NULL debug tag entry
57  }
58
59  const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
60  if (abbrevDecl == nullptr) {
61    cu->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
62        "[{0:x16}]: invalid abbreviation code {1}, "
63        "please file a bug and "
64        "attach the file at the start of this error message",
65        (uint64_t)m_offset, (unsigned)abbr_idx);
66    // WE can't parse anymore if the DWARF is borked...
67    *offset_ptr = UINT32_MAX;
68    return false;
69  }
70  m_tag = abbrevDecl->getTag();
71  m_has_children = abbrevDecl->hasChildren();
72  // Skip all data in the .debug_info or .debug_types for the attributes
73  for (const auto &attribute : abbrevDecl->attributes()) {
74    if (DWARFFormValue::SkipValue(attribute.Form, data, offset_ptr, cu))
75      continue;
76
77    cu->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
78        "[{0:x16}]: Unsupported DW_FORM_{1:x}, please file a bug "
79        "and "
80        "attach the file at the start of this error message",
81        (uint64_t)m_offset, (unsigned)attribute.Form);
82    *offset_ptr = m_offset;
83    return false;
84  }
85  return true;
86}
87
88static DWARFRangeList GetRangesOrReportError(DWARFUnit &unit,
89                                             const DWARFDebugInfoEntry &die,
90                                             const DWARFFormValue &value) {
91  llvm::Expected<DWARFRangeList> expected_ranges =
92      (value.Form() == DW_FORM_rnglistx)
93          ? unit.FindRnglistFromIndex(value.Unsigned())
94          : unit.FindRnglistFromOffset(value.Unsigned());
95  if (expected_ranges)
96    return std::move(*expected_ranges);
97
98  unit.GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
99      "[{0:x16}]: DIE has DW_AT_ranges({1} {2:x16}) attribute, but "
100      "range extraction failed ({3}), please file a bug "
101      "and attach the file at the start of this error message",
102      die.GetOffset(),
103      llvm::dwarf::FormEncodingString(value.Form()).str().c_str(),
104      value.Unsigned(), toString(expected_ranges.takeError()).c_str());
105  return DWARFRangeList();
106}
107
108static void ExtractAttrAndFormValue(
109    const llvm::DWARFAbbreviationDeclaration::AttributeSpec &attr_spec,
110    dw_attr_t &attr, DWARFFormValue &form_value) {
111  attr = attr_spec.Attr;
112  form_value.FormRef() = attr_spec.Form;
113  if (attr_spec.isImplicitConst())
114    form_value.SetSigned(attr_spec.getImplicitConstValue());
115}
116
117// GetDIENamesAndRanges
118//
119// Gets the valid address ranges for a given DIE by looking for a
120// DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.
121bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
122    DWARFUnit *cu, const char *&name, const char *&mangled,
123    DWARFRangeList &ranges, std::optional<int> &decl_file,
124    std::optional<int> &decl_line, std::optional<int> &decl_column,
125    std::optional<int> &call_file, std::optional<int> &call_line,
126    std::optional<int> &call_column, DWARFExpressionList *frame_base) const {
127  dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
128  dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
129  std::vector<DWARFDIE> dies;
130  bool set_frame_base_loclist_addr = false;
131
132  SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
133  lldb::ModuleSP module = dwarf.GetObjectFile()->GetModule();
134
135  if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
136    const DWARFDataExtractor &data = cu->GetData();
137    lldb::offset_t offset = GetFirstAttributeOffset();
138
139    if (!data.ValidOffset(offset))
140      return false;
141
142    bool do_offset = false;
143
144    for (const auto &attribute : abbrevDecl->attributes()) {
145      DWARFFormValue form_value(cu);
146      dw_attr_t attr;
147      ExtractAttrAndFormValue(attribute, attr, form_value);
148
149      if (form_value.ExtractValue(data, &offset)) {
150        switch (attr) {
151        case DW_AT_low_pc:
152          lo_pc = form_value.Address();
153
154          if (do_offset)
155            hi_pc += lo_pc;
156          do_offset = false;
157          break;
158
159        case DW_AT_entry_pc:
160          lo_pc = form_value.Address();
161          break;
162
163        case DW_AT_high_pc:
164          if (form_value.Form() == DW_FORM_addr ||
165              form_value.Form() == DW_FORM_addrx ||
166              form_value.Form() == DW_FORM_GNU_addr_index) {
167            hi_pc = form_value.Address();
168          } else {
169            hi_pc = form_value.Unsigned();
170            if (lo_pc == LLDB_INVALID_ADDRESS)
171              do_offset = hi_pc != LLDB_INVALID_ADDRESS;
172            else
173              hi_pc += lo_pc; // DWARF 4 introduces <offset-from-lo-pc> to save
174                              // on relocations
175          }
176          break;
177
178        case DW_AT_ranges:
179          ranges = GetRangesOrReportError(*cu, *this, form_value);
180          break;
181
182        case DW_AT_name:
183          if (name == nullptr)
184            name = form_value.AsCString();
185          break;
186
187        case DW_AT_MIPS_linkage_name:
188        case DW_AT_linkage_name:
189          if (mangled == nullptr)
190            mangled = form_value.AsCString();
191          break;
192
193        case DW_AT_abstract_origin:
194          dies.push_back(form_value.Reference());
195          break;
196
197        case DW_AT_specification:
198          dies.push_back(form_value.Reference());
199          break;
200
201        case DW_AT_decl_file:
202          if (!decl_file)
203            decl_file = form_value.Unsigned();
204          break;
205
206        case DW_AT_decl_line:
207          if (!decl_line)
208            decl_line = form_value.Unsigned();
209          break;
210
211        case DW_AT_decl_column:
212          if (!decl_column)
213            decl_column = form_value.Unsigned();
214          break;
215
216        case DW_AT_call_file:
217          if (!call_file)
218            call_file = form_value.Unsigned();
219          break;
220
221        case DW_AT_call_line:
222          if (!call_line)
223            call_line = form_value.Unsigned();
224          break;
225
226        case DW_AT_call_column:
227          if (!call_column)
228            call_column = form_value.Unsigned();
229          break;
230
231        case DW_AT_frame_base:
232          if (frame_base) {
233            if (form_value.BlockData()) {
234              uint32_t block_offset =
235                  form_value.BlockData() - data.GetDataStart();
236              uint32_t block_length = form_value.Unsigned();
237              *frame_base =
238                  DWARFExpressionList(module,
239                                      DWARFExpression(DataExtractor(
240                                          data, block_offset, block_length)),
241                                      cu);
242            } else {
243              DataExtractor data = cu->GetLocationData();
244              const dw_offset_t offset = form_value.Unsigned();
245              if (data.ValidOffset(offset)) {
246                data = DataExtractor(data, offset, data.GetByteSize() - offset);
247                if (lo_pc != LLDB_INVALID_ADDRESS) {
248                  assert(lo_pc >= cu->GetBaseAddress());
249                  DWARFExpression::ParseDWARFLocationList(cu, data, frame_base);
250                  frame_base->SetFuncFileAddress(lo_pc);
251                } else
252                  set_frame_base_loclist_addr = true;
253              }
254            }
255          }
256          break;
257
258        default:
259          break;
260        }
261      }
262    }
263  }
264
265  if (ranges.IsEmpty()) {
266    if (lo_pc != LLDB_INVALID_ADDRESS) {
267      if (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc)
268        ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
269      else
270        ranges.Append(DWARFRangeList::Entry(lo_pc, 0));
271    }
272  }
273
274  if (set_frame_base_loclist_addr) {
275    dw_addr_t lowest_range_pc = ranges.GetMinRangeBase(0);
276    assert(lowest_range_pc >= cu->GetBaseAddress());
277    frame_base->SetFuncFileAddress(lowest_range_pc);
278  }
279
280  if (ranges.IsEmpty() || name == nullptr || mangled == nullptr) {
281    for (const DWARFDIE &die : dies) {
282      if (die) {
283        die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,
284                                           decl_file, decl_line, decl_column,
285                                           call_file, call_line, call_column);
286      }
287    }
288  }
289  return !ranges.IsEmpty();
290}
291
292// Get all attribute values for a given DIE, including following any
293// specification or abstract origin attributes and including those in the
294// results. Any duplicate attributes will have the first instance take
295// precedence (this can happen for declaration attributes).
296void DWARFDebugInfoEntry::GetAttributes(DWARFUnit *cu,
297                                        DWARFAttributes &attributes,
298                                        Recurse recurse,
299                                        uint32_t curr_depth) const {
300  const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
301  if (!abbrevDecl) {
302    attributes.Clear();
303    return;
304  }
305
306  const DWARFDataExtractor &data = cu->GetData();
307  lldb::offset_t offset = GetFirstAttributeOffset();
308
309  for (const auto &attribute : abbrevDecl->attributes()) {
310    DWARFFormValue form_value(cu);
311    dw_attr_t attr;
312    ExtractAttrAndFormValue(attribute, attr, form_value);
313
314    // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
315    // attributes, the depth will be non-zero. We need to omit certain
316    // attributes that don't make sense.
317    switch (attr) {
318    case DW_AT_sibling:
319    case DW_AT_declaration:
320      if (curr_depth > 0) {
321        // This attribute doesn't make sense when combined with the DIE that
322        // references this DIE. We know a DIE is referencing this DIE because
323        // curr_depth is not zero
324        break;
325      }
326      [[fallthrough]];
327    default:
328      attributes.Append(form_value, offset, attr);
329      break;
330    }
331
332    if (recurse == Recurse::yes &&
333        ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin))) {
334      if (form_value.ExtractValue(data, &offset)) {
335        DWARFDIE spec_die = form_value.Reference();
336        if (spec_die)
337          spec_die.GetDIE()->GetAttributes(spec_die.GetCU(), attributes,
338                                           recurse, curr_depth + 1);
339      }
340    } else {
341      const dw_form_t form = form_value.Form();
342      std::optional<uint8_t> fixed_skip_size =
343          DWARFFormValue::GetFixedSize(form, cu);
344      if (fixed_skip_size)
345        offset += *fixed_skip_size;
346      else
347        DWARFFormValue::SkipValue(form, data, &offset, cu);
348    }
349  }
350}
351
352// GetAttributeValue
353//
354// Get the value of an attribute and return the .debug_info or .debug_types
355// offset of the attribute if it was properly extracted into form_value,
356// or zero if we fail since an offset of zero is invalid for an attribute (it
357// would be a compile unit header).
358dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
359    const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
360    dw_offset_t *end_attr_offset_ptr,
361    bool check_specification_or_abstract_origin) const {
362  if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
363    std::optional<uint32_t> attr_idx = abbrevDecl->findAttributeIndex(attr);
364
365    if (attr_idx) {
366      const DWARFDataExtractor &data = cu->GetData();
367      lldb::offset_t offset = GetFirstAttributeOffset();
368
369      uint32_t idx = 0;
370      while (idx < *attr_idx)
371        DWARFFormValue::SkipValue(abbrevDecl->getFormByIndex(idx++), data,
372                                  &offset, cu);
373
374      const dw_offset_t attr_offset = offset;
375      form_value.SetUnit(cu);
376      form_value.SetForm(abbrevDecl->getFormByIndex(idx));
377      if (form_value.ExtractValue(data, &offset)) {
378        if (end_attr_offset_ptr)
379          *end_attr_offset_ptr = offset;
380        return attr_offset;
381      }
382    }
383  }
384
385  if (check_specification_or_abstract_origin) {
386    if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
387      DWARFDIE die = form_value.Reference();
388      if (die) {
389        dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
390            die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
391        if (die_offset)
392          return die_offset;
393      }
394    }
395
396    if (GetAttributeValue(cu, DW_AT_abstract_origin, form_value)) {
397      DWARFDIE die = form_value.Reference();
398      if (die) {
399        dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
400            die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
401        if (die_offset)
402          return die_offset;
403      }
404    }
405  }
406  return 0;
407}
408
409// GetAttributeValueAsString
410//
411// Get the value of an attribute as a string return it. The resulting pointer
412// to the string data exists within the supplied SymbolFileDWARF and will only
413// be available as long as the SymbolFileDWARF is still around and it's content
414// doesn't change.
415const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
416    const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
417    bool check_specification_or_abstract_origin) const {
418  DWARFFormValue form_value;
419  if (GetAttributeValue(cu, attr, form_value, nullptr,
420                        check_specification_or_abstract_origin))
421    return form_value.AsCString();
422  return fail_value;
423}
424
425// GetAttributeValueAsUnsigned
426//
427// Get the value of an attribute as unsigned and return it.
428uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
429    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
430    bool check_specification_or_abstract_origin) const {
431  DWARFFormValue form_value;
432  if (GetAttributeValue(cu, attr, form_value, nullptr,
433                        check_specification_or_abstract_origin))
434    return form_value.Unsigned();
435  return fail_value;
436}
437
438std::optional<uint64_t>
439DWARFDebugInfoEntry::GetAttributeValueAsOptionalUnsigned(
440    const DWARFUnit *cu, const dw_attr_t attr,
441    bool check_specification_or_abstract_origin) const {
442  DWARFFormValue form_value;
443  if (GetAttributeValue(cu, attr, form_value, nullptr,
444                        check_specification_or_abstract_origin))
445    return form_value.Unsigned();
446  return std::nullopt;
447}
448
449// GetAttributeValueAsReference
450//
451// Get the value of an attribute as reference and fix up and compile unit
452// relative offsets as needed.
453DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
454    const DWARFUnit *cu, const dw_attr_t attr,
455    bool check_specification_or_abstract_origin) const {
456  DWARFFormValue form_value;
457  if (GetAttributeValue(cu, attr, form_value, nullptr,
458                        check_specification_or_abstract_origin))
459    return form_value.Reference();
460  return {};
461}
462
463uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
464    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
465    bool check_specification_or_abstract_origin) const {
466  DWARFFormValue form_value;
467  if (GetAttributeValue(cu, attr, form_value, nullptr,
468                        check_specification_or_abstract_origin))
469    return form_value.Address();
470  return fail_value;
471}
472
473// GetAttributeHighPC
474//
475// Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
476// pc>.
477//
478// Returns the hi_pc or fail_value.
479dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
480    const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
481    bool check_specification_or_abstract_origin) const {
482  DWARFFormValue form_value;
483  if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
484                        check_specification_or_abstract_origin)) {
485    dw_form_t form = form_value.Form();
486    if (form == DW_FORM_addr || form == DW_FORM_addrx ||
487        form == DW_FORM_GNU_addr_index)
488      return form_value.Address();
489
490    // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
491    return lo_pc + form_value.Unsigned();
492  }
493  return fail_value;
494}
495
496// GetAttributeAddressRange
497//
498// Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
499// from-low-pc>.
500//
501// Returns true or sets lo_pc and hi_pc to fail_value.
502bool DWARFDebugInfoEntry::GetAttributeAddressRange(
503    const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
504    uint64_t fail_value, bool check_specification_or_abstract_origin) const {
505  lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
506                                     check_specification_or_abstract_origin);
507  if (lo_pc != fail_value) {
508    hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
509                               check_specification_or_abstract_origin);
510    if (hi_pc != fail_value)
511      return true;
512  }
513  lo_pc = fail_value;
514  hi_pc = fail_value;
515  return false;
516}
517
518DWARFRangeList DWARFDebugInfoEntry::GetAttributeAddressRanges(
519    DWARFUnit *cu, bool check_hi_lo_pc,
520    bool check_specification_or_abstract_origin) const {
521
522  DWARFFormValue form_value;
523  if (GetAttributeValue(cu, DW_AT_ranges, form_value))
524    return GetRangesOrReportError(*cu, *this, form_value);
525
526  DWARFRangeList ranges;
527  if (check_hi_lo_pc) {
528    dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
529    dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
530    if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
531                                 check_specification_or_abstract_origin)) {
532      if (lo_pc < hi_pc)
533        ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
534    }
535  }
536  return ranges;
537}
538
539// GetName
540//
541// Get value of the DW_AT_name attribute and return it if one exists, else
542// return NULL.
543const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
544  return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
545}
546
547// GetMangledName
548//
549// Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
550// exists, else return the value of the DW_AT_name attribute
551const char *
552DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
553                                    bool substitute_name_allowed) const {
554  const char *name = nullptr;
555
556  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
557  if (name)
558    return name;
559
560  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
561  if (name)
562    return name;
563
564  if (!substitute_name_allowed)
565    return nullptr;
566
567  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
568  return name;
569}
570
571// GetPubname
572//
573// Get value the name for a DIE as it should appear for a .debug_pubnames or
574// .debug_pubtypes section.
575const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
576  const char *name = nullptr;
577  if (!cu)
578    return name;
579
580  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
581  if (name)
582    return name;
583
584  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
585  if (name)
586    return name;
587
588  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
589  return name;
590}
591
592/// This function is builds a table very similar to the standard .debug_aranges
593/// table, except that the actual DIE offset for the function is placed in the
594/// table instead of the compile unit offset.
595void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
596    DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
597  if (m_tag) {
598    if (m_tag == DW_TAG_subprogram) {
599      DWARFRangeList ranges =
600          GetAttributeAddressRanges(cu, /*check_hi_lo_pc=*/true);
601      for (const auto &r : ranges) {
602        debug_aranges->AppendRange(GetOffset(), r.GetRangeBase(),
603                                   r.GetRangeEnd());
604      }
605    }
606
607    const DWARFDebugInfoEntry *child = GetFirstChild();
608    while (child) {
609      child->BuildFunctionAddressRangeTable(cu, debug_aranges);
610      child = child->GetSibling();
611    }
612  }
613}
614
615DWARFDeclContext
616DWARFDebugInfoEntry::GetDWARFDeclContextStatic(const DWARFDebugInfoEntry *die,
617                                               DWARFUnit *cu) {
618  DWARFDeclContext dwarf_decl_ctx;
619  for (;;) {
620    const dw_tag_t tag = die->Tag();
621    if (tag == DW_TAG_compile_unit || tag == DW_TAG_partial_unit)
622      return dwarf_decl_ctx;
623    dwarf_decl_ctx.AppendDeclContext(tag, die->GetName(cu));
624    DWARFDIE parent_decl_ctx_die = die->GetParentDeclContextDIE(cu);
625    if (!parent_decl_ctx_die || parent_decl_ctx_die.GetDIE() == die)
626      return dwarf_decl_ctx;
627    if (parent_decl_ctx_die.Tag() == DW_TAG_compile_unit ||
628        parent_decl_ctx_die.Tag() == DW_TAG_partial_unit)
629      return dwarf_decl_ctx;
630    die = parent_decl_ctx_die.GetDIE();
631    cu = parent_decl_ctx_die.GetCU();
632  }
633}
634
635DWARFDeclContext DWARFDebugInfoEntry::GetDWARFDeclContext(DWARFUnit *cu) const {
636  return GetDWARFDeclContextStatic(this, cu);
637}
638
639DWARFDIE
640DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
641  DWARFAttributes attributes = GetAttributes(cu, Recurse::yes);
642  return GetParentDeclContextDIE(cu, attributes);
643}
644
645DWARFDIE
646DWARFDebugInfoEntry::GetParentDeclContextDIE(
647    DWARFUnit *cu, const DWARFAttributes &attributes) const {
648  DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
649
650  while (die) {
651    // If this is the original DIE that we are searching for a declaration for,
652    // then don't look in the cache as we don't want our own decl context to be
653    // our decl context...
654    if (die.GetDIE() != this) {
655      switch (die.Tag()) {
656      case DW_TAG_compile_unit:
657      case DW_TAG_partial_unit:
658      case DW_TAG_namespace:
659      case DW_TAG_structure_type:
660      case DW_TAG_union_type:
661      case DW_TAG_class_type:
662        return die;
663
664      default:
665        break;
666      }
667    }
668
669    DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
670    if (spec_die) {
671      DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
672      if (decl_ctx_die)
673        return decl_ctx_die;
674    }
675
676    DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
677    if (abs_die) {
678      DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
679      if (decl_ctx_die)
680        return decl_ctx_die;
681    }
682
683    die = die.GetParent();
684  }
685  return DWARFDIE();
686}
687
688lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
689  return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
690}
691
692const llvm::DWARFAbbreviationDeclaration *
693DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
694  if (!cu)
695    return nullptr;
696
697  const llvm::DWARFAbbreviationDeclarationSet *abbrev_set =
698      cu->GetAbbreviations();
699  if (!abbrev_set)
700    return nullptr;
701
702  return abbrev_set->getAbbreviationDeclaration(m_abbr_idx);
703}
704
705bool DWARFDebugInfoEntry::IsGlobalOrStaticScopeVariable() const {
706  if (Tag() != DW_TAG_variable)
707    return false;
708  const DWARFDebugInfoEntry *parent_die = GetParent();
709  while (parent_die != nullptr) {
710    switch (parent_die->Tag()) {
711    case DW_TAG_subprogram:
712    case DW_TAG_lexical_block:
713    case DW_TAG_inlined_subroutine:
714      return false;
715
716    case DW_TAG_compile_unit:
717    case DW_TAG_partial_unit:
718      return true;
719
720    default:
721      break;
722    }
723    parent_die = parent_die->GetParent();
724  }
725  return false;
726}
727
728bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
729  return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
730         m_sibling_idx == rhs.m_sibling_idx &&
731         m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
732         m_tag == rhs.m_tag;
733}
734
735bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
736  return !(*this == rhs);
737}
738