DWARFDebugInfoEntry.cpp revision 355940 
1//===-- DWARFDebugInfoEntry.cpp ---------------------------------*- C++ -*-===//
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
33using namespace lldb_private;
34using namespace std;
35extern 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
39bool 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) {
53    lldb::offset_t offset = *offset_ptr;
54    const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
55    if (abbrevDecl == nullptr) {
56      cu->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
57          "{0x%8.8x}: invalid abbreviation code %u, please file a bug and "
58          "attach the file at the start of this error message",
59          m_offset, (unsigned)abbr_idx);
60      // WE can't parse anymore if the DWARF is borked...
61      *offset_ptr = UINT32_MAX;
62      return false;
63    }
64    m_tag = abbrevDecl->Tag();
65    m_has_children = abbrevDecl->HasChildren();
66    // Skip all data in the .debug_info or .debug_types for the attributes
67    const uint32_t numAttributes = abbrevDecl->NumAttributes();
68    uint32_t i;
69    dw_form_t form;
70    for (i = 0; i < numAttributes; ++i) {
71      form = abbrevDecl->GetFormByIndexUnchecked(i);
72      llvm::Optional<uint8_t> fixed_skip_size =
73          DWARFFormValue::GetFixedSize(form, cu);
74      if (fixed_skip_size)
75        offset += *fixed_skip_size;
76      else {
77        bool form_is_indirect = false;
78        do {
79          form_is_indirect = false;
80          uint32_t form_size = 0;
81          switch (form) {
82          // Blocks if inlined data that have a length field and the data bytes
83          // inlined in the .debug_info/.debug_types
84          case DW_FORM_exprloc:
85          case DW_FORM_block:
86            form_size = data.GetULEB128(&offset);
87            break;
88          case DW_FORM_block1:
89            form_size = data.GetU8_unchecked(&offset);
90            break;
91          case DW_FORM_block2:
92            form_size = data.GetU16_unchecked(&offset);
93            break;
94          case DW_FORM_block4:
95            form_size = data.GetU32_unchecked(&offset);
96            break;
97
98          // Inlined NULL terminated C-strings
99          case DW_FORM_string:
100            data.GetCStr(&offset);
101            break;
102
103          // Compile unit address sized values
104          case DW_FORM_addr:
105            form_size = cu->GetAddressByteSize();
106            break;
107          case DW_FORM_ref_addr:
108            if (cu->GetVersion() <= 2)
109              form_size = cu->GetAddressByteSize();
110            else
111              form_size = 4;
112            break;
113
114          // 0 sized form
115          case DW_FORM_flag_present:
116            form_size = 0;
117            break;
118
119          // 1 byte values
120          case DW_FORM_addrx1:
121          case DW_FORM_data1:
122          case DW_FORM_flag:
123          case DW_FORM_ref1:
124          case DW_FORM_strx1:
125            form_size = 1;
126            break;
127
128          // 2 byte values
129          case DW_FORM_addrx2:
130          case DW_FORM_data2:
131          case DW_FORM_ref2:
132          case DW_FORM_strx2:
133            form_size = 2;
134            break;
135
136          // 3 byte values
137          case DW_FORM_addrx3:
138          case DW_FORM_strx3:
139            form_size = 3;
140            break;
141
142          // 4 byte values
143          case DW_FORM_addrx4:
144          case DW_FORM_data4:
145          case DW_FORM_ref4:
146          case DW_FORM_strx4:
147            form_size = 4;
148            break;
149
150          // 8 byte values
151          case DW_FORM_data8:
152          case DW_FORM_ref8:
153          case DW_FORM_ref_sig8:
154            form_size = 8;
155            break;
156
157          // signed or unsigned LEB 128 values
158          case DW_FORM_addrx:
159          case DW_FORM_rnglistx:
160          case DW_FORM_sdata:
161          case DW_FORM_udata:
162          case DW_FORM_ref_udata:
163          case DW_FORM_GNU_addr_index:
164          case DW_FORM_GNU_str_index:
165          case DW_FORM_strx:
166            data.Skip_LEB128(&offset);
167            break;
168
169          case DW_FORM_indirect:
170            form_is_indirect = true;
171            form = data.GetULEB128(&offset);
172            break;
173
174          case DW_FORM_strp:
175          case DW_FORM_sec_offset:
176            data.GetU32(&offset);
177            break;
178
179          case DW_FORM_implicit_const:
180            form_size = 0;
181            break;
182
183          default:
184            *offset_ptr = m_offset;
185            return false;
186          }
187          offset += form_size;
188
189        } while (form_is_indirect);
190      }
191    }
192    *offset_ptr = offset;
193    return true;
194  } else {
195    m_tag = 0;
196    m_has_children = false;
197    return true; // NULL debug tag entry
198  }
199
200  return false;
201}
202
203static DWARFRangeList GetRangesOrReportError(const DWARFUnit &unit,
204                                             const DWARFDebugInfoEntry &die,
205                                             const DWARFFormValue &value) {
206  llvm::Expected<DWARFRangeList> expected_ranges =
207      (value.Form() == DW_FORM_rnglistx)
208          ? unit.FindRnglistFromIndex(value.Unsigned())
209          : unit.FindRnglistFromOffset(value.Unsigned());
210  if (expected_ranges)
211    return std::move(*expected_ranges);
212  unit.GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
213      "{0x%8.8x}: DIE has DW_AT_ranges(0x%" PRIx64 ") attribute, but "
214      "range extraction failed (%s), please file a bug "
215      "and attach the file at the start of this error message",
216      die.GetOffset(), value.Unsigned(),
217      toString(expected_ranges.takeError()).c_str());
218  return DWARFRangeList();
219}
220
221// GetDIENamesAndRanges
222//
223// Gets the valid address ranges for a given DIE by looking for a
224// DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.
225bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
226    const DWARFUnit *cu, const char *&name, const char *&mangled,
227    DWARFRangeList &ranges, int &decl_file, int &decl_line, int &decl_column,
228    int &call_file, int &call_line, int &call_column,
229    DWARFExpression *frame_base) const {
230  dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
231  dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
232  std::vector<DWARFDIE> dies;
233  bool set_frame_base_loclist_addr = false;
234
235  const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
236
237  SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
238  lldb::ModuleSP module = dwarf.GetObjectFile()->GetModule();
239
240  if (abbrevDecl) {
241    const DWARFDataExtractor &data = cu->GetData();
242    lldb::offset_t offset = GetFirstAttributeOffset();
243
244    if (!data.ValidOffset(offset))
245      return false;
246
247    const uint32_t numAttributes = abbrevDecl->NumAttributes();
248    bool do_offset = false;
249
250    for (uint32_t i = 0; i < numAttributes; ++i) {
251      DWARFFormValue form_value(cu);
252      dw_attr_t attr;
253      abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
254
255      if (form_value.ExtractValue(data, &offset)) {
256        switch (attr) {
257        case DW_AT_low_pc:
258          lo_pc = form_value.Address();
259
260          if (do_offset)
261            hi_pc += lo_pc;
262          do_offset = false;
263          break;
264
265        case DW_AT_entry_pc:
266          lo_pc = form_value.Address();
267          break;
268
269        case DW_AT_high_pc:
270          if (form_value.Form() == DW_FORM_addr ||
271              form_value.Form() == DW_FORM_addrx ||
272              form_value.Form() == DW_FORM_GNU_addr_index) {
273            hi_pc = form_value.Address();
274          } else {
275            hi_pc = form_value.Unsigned();
276            if (lo_pc == LLDB_INVALID_ADDRESS)
277              do_offset = hi_pc != LLDB_INVALID_ADDRESS;
278            else
279              hi_pc += lo_pc; // DWARF 4 introduces <offset-from-lo-pc> to save
280                              // on relocations
281          }
282          break;
283
284        case DW_AT_ranges:
285          ranges = GetRangesOrReportError(*cu, *this, form_value);
286          break;
287
288        case DW_AT_name:
289          if (name == nullptr)
290            name = form_value.AsCString();
291          break;
292
293        case DW_AT_MIPS_linkage_name:
294        case DW_AT_linkage_name:
295          if (mangled == nullptr)
296            mangled = form_value.AsCString();
297          break;
298
299        case DW_AT_abstract_origin:
300          dies.push_back(form_value.Reference());
301          break;
302
303        case DW_AT_specification:
304          dies.push_back(form_value.Reference());
305          break;
306
307        case DW_AT_decl_file:
308          if (decl_file == 0)
309            decl_file = form_value.Unsigned();
310          break;
311
312        case DW_AT_decl_line:
313          if (decl_line == 0)
314            decl_line = form_value.Unsigned();
315          break;
316
317        case DW_AT_decl_column:
318          if (decl_column == 0)
319            decl_column = form_value.Unsigned();
320          break;
321
322        case DW_AT_call_file:
323          if (call_file == 0)
324            call_file = form_value.Unsigned();
325          break;
326
327        case DW_AT_call_line:
328          if (call_line == 0)
329            call_line = form_value.Unsigned();
330          break;
331
332        case DW_AT_call_column:
333          if (call_column == 0)
334            call_column = form_value.Unsigned();
335          break;
336
337        case DW_AT_frame_base:
338          if (frame_base) {
339            if (form_value.BlockData()) {
340              uint32_t block_offset =
341                  form_value.BlockData() - data.GetDataStart();
342              uint32_t block_length = form_value.Unsigned();
343              *frame_base = DWARFExpression(module, data, cu,
344                                            block_offset, block_length);
345            } else {
346              const DWARFDataExtractor &debug_loc_data = dwarf.DebugLocData();
347              const dw_offset_t debug_loc_offset = form_value.Unsigned();
348
349              size_t loc_list_length = DWARFExpression::LocationListSize(
350                  cu, debug_loc_data, debug_loc_offset);
351              if (loc_list_length > 0) {
352                *frame_base =
353                    DWARFExpression(module, debug_loc_data, cu,
354                                    debug_loc_offset, loc_list_length);
355                if (lo_pc != LLDB_INVALID_ADDRESS) {
356                  assert(lo_pc >= cu->GetBaseAddress());
357                  frame_base->SetLocationListSlide(lo_pc -
358                                                   cu->GetBaseAddress());
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->SetLocationListSlide(lowest_range_pc - cu->GetBaseAddress());
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// Dump
402//
403// Dumps a debug information entry and all of it's attributes to the specified
404// stream.
405void DWARFDebugInfoEntry::Dump(const DWARFUnit *cu, Stream &s,
406                               uint32_t recurse_depth) const {
407  const DWARFDataExtractor &data = cu->GetData();
408  lldb::offset_t offset = m_offset;
409
410  if (data.ValidOffset(offset)) {
411    dw_uleb128_t abbrCode = data.GetULEB128(&offset);
412
413    s.Printf("\n0x%8.8x: ", m_offset);
414    s.Indent();
415    if (abbrCode != m_abbr_idx) {
416      s.Printf("error: DWARF has been modified\n");
417    } else if (abbrCode) {
418      const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
419      if (abbrevDecl) {
420        s.PutCString(DW_TAG_value_to_name(abbrevDecl->Tag()));
421        s.Printf(" [%u] %c\n", abbrCode, abbrevDecl->HasChildren() ? '*' : ' ');
422
423        // Dump all data in the .debug_info/.debug_types for the attributes
424        const uint32_t numAttributes = abbrevDecl->NumAttributes();
425        for (uint32_t i = 0; i < numAttributes; ++i) {
426          DWARFFormValue form_value(cu);
427          dw_attr_t attr;
428          abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
429
430          DumpAttribute(cu, data, &offset, s, attr, form_value);
431        }
432
433        const DWARFDebugInfoEntry *child = GetFirstChild();
434        if (recurse_depth > 0 && child) {
435          s.IndentMore();
436
437          while (child) {
438            child->Dump(cu, s, recurse_depth - 1);
439            child = child->GetSibling();
440          }
441          s.IndentLess();
442        }
443      } else
444        s.Printf("Abbreviation code note found in 'debug_abbrev' class for "
445                 "code: %u\n",
446                 abbrCode);
447    } else {
448      s.Printf("NULL\n");
449    }
450  }
451}
452
453// DumpAttribute
454//
455// Dumps a debug information entry attribute along with it's form. Any special
456// display of attributes is done (disassemble location lists, show enumeration
457// values for attributes, etc).
458void DWARFDebugInfoEntry::DumpAttribute(
459    const DWARFUnit *cu, const DWARFDataExtractor &data,
460    lldb::offset_t *offset_ptr, Stream &s, dw_attr_t attr,
461    DWARFFormValue &form_value) {
462  bool show_form = s.GetFlags().Test(DWARFDebugInfo::eDumpFlag_ShowForm);
463
464  s.Printf("            ");
465  s.Indent(DW_AT_value_to_name(attr));
466
467  if (show_form) {
468    s.Printf("[%s", DW_FORM_value_to_name(form_value.Form()));
469  }
470
471  if (!form_value.ExtractValue(data, offset_ptr))
472    return;
473
474  if (show_form) {
475    if (form_value.Form() == DW_FORM_indirect) {
476      s.Printf(" [%s]", DW_FORM_value_to_name(form_value.Form()));
477    }
478
479    s.PutCString("] ");
480  }
481
482  s.PutCString("( ");
483
484  SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
485
486  // Check to see if we have any special attribute formatters
487  switch (attr) {
488  case DW_AT_stmt_list:
489    s.Printf("0x%8.8" PRIx64, form_value.Unsigned());
490    break;
491
492  case DW_AT_language:
493    s.PutCString(DW_LANG_value_to_name(form_value.Unsigned()));
494    break;
495
496  case DW_AT_encoding:
497    s.PutCString(DW_ATE_value_to_name(form_value.Unsigned()));
498    break;
499
500  case DW_AT_frame_base:
501  case DW_AT_location:
502  case DW_AT_data_member_location: {
503    const uint8_t *blockData = form_value.BlockData();
504    if (blockData) {
505      // Location description is inlined in data in the form value
506      DWARFDataExtractor locationData(data,
507                                      (*offset_ptr) - form_value.Unsigned(),
508                                      form_value.Unsigned());
509      DWARFExpression::PrintDWARFExpression(
510          s, locationData, DWARFUnit::GetAddressByteSize(cu), 4, false);
511    } else {
512      // We have a location list offset as the value that is the offset into
513      // the .debug_loc section that describes the value over it's lifetime
514      uint64_t debug_loc_offset = form_value.Unsigned();
515      DWARFExpression::PrintDWARFLocationList(s, cu, dwarf.DebugLocData(),
516                                              debug_loc_offset);
517    }
518  } break;
519
520  case DW_AT_abstract_origin:
521  case DW_AT_specification: {
522    DWARFDIE abstract_die = form_value.Reference();
523    form_value.Dump(s);
524    //  *ostrm_ptr << HEX32 << abstract_die.GetOffset() << " ( ";
525    abstract_die.GetName(s);
526  } break;
527
528  case DW_AT_type: {
529    DWARFDIE type_die = form_value.Reference();
530    s.PutCString(" ( ");
531    type_die.AppendTypeName(s);
532    s.PutCString(" )");
533  } break;
534
535  default:
536    break;
537  }
538
539  s.PutCString(" )\n");
540}
541
542// Get all attribute values for a given DIE, including following any
543// specification or abstract origin attributes and including those in the
544// results. Any duplicate attributes will have the first instance take
545// precedence (this can happen for declaration attributes).
546size_t DWARFDebugInfoEntry::GetAttributes(
547    const DWARFUnit *cu, DWARFAttributes &attributes,
548    uint32_t curr_depth) const {
549  const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
550  if (abbrevDecl) {
551    const DWARFDataExtractor &data = cu->GetData();
552    lldb::offset_t offset = GetFirstAttributeOffset();
553
554    const uint32_t num_attributes = abbrevDecl->NumAttributes();
555    for (uint32_t i = 0; i < num_attributes; ++i) {
556      DWARFFormValue form_value(cu);
557      dw_attr_t attr;
558      abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
559      const dw_form_t form = form_value.Form();
560
561      // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
562      // attributes, the depth will be non-zero. We need to omit certain
563      // attributes that don't make sense.
564      switch (attr) {
565      case DW_AT_sibling:
566      case DW_AT_declaration:
567        if (curr_depth > 0) {
568          // This attribute doesn't make sense when combined with the DIE that
569          // references this DIE. We know a DIE is referencing this DIE because
570          // curr_depth is not zero
571          break;
572        }
573        LLVM_FALLTHROUGH;
574      default:
575        attributes.Append(cu, offset, attr, form);
576        break;
577      }
578
579      if ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin)) {
580        if (form_value.ExtractValue(data, &offset)) {
581          DWARFDIE spec_die = form_value.Reference();
582          if (spec_die)
583            spec_die.GetAttributes(attributes, curr_depth + 1);
584        }
585      } else {
586        llvm::Optional<uint8_t> fixed_skip_size = DWARFFormValue::GetFixedSize(form, cu);
587        if (fixed_skip_size)
588          offset += *fixed_skip_size;
589        else
590          DWARFFormValue::SkipValue(form, data, &offset, cu);
591      }
592    }
593  } else {
594    attributes.Clear();
595  }
596  return attributes.Size();
597}
598
599// GetAttributeValue
600//
601// Get the value of an attribute and return the .debug_info or .debug_types
602// offset of the attribute if it was properly extracted into form_value,
603// or zero if we fail since an offset of zero is invalid for an attribute (it
604// would be a compile unit header).
605dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
606    const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
607    dw_offset_t *end_attr_offset_ptr,
608    bool check_specification_or_abstract_origin) const {
609  if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
610    uint32_t attr_idx = abbrevDecl->FindAttributeIndex(attr);
611
612    if (attr_idx != DW_INVALID_INDEX) {
613      const DWARFDataExtractor &data = cu->GetData();
614      lldb::offset_t offset = GetFirstAttributeOffset();
615
616      uint32_t idx = 0;
617      while (idx < attr_idx)
618        DWARFFormValue::SkipValue(abbrevDecl->GetFormByIndex(idx++),
619                                  data, &offset, cu);
620
621      const dw_offset_t attr_offset = offset;
622      form_value.SetUnit(cu);
623      form_value.SetForm(abbrevDecl->GetFormByIndex(idx));
624      if (form_value.ExtractValue(data, &offset)) {
625        if (end_attr_offset_ptr)
626          *end_attr_offset_ptr = offset;
627        return attr_offset;
628      }
629    }
630  }
631
632  if (check_specification_or_abstract_origin) {
633    if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
634      DWARFDIE die = form_value.Reference();
635      if (die) {
636        dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
637            die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
638        if (die_offset)
639          return die_offset;
640      }
641    }
642
643    if (GetAttributeValue(cu, DW_AT_abstract_origin, form_value)) {
644      DWARFDIE die = form_value.Reference();
645      if (die) {
646        dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
647            die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
648        if (die_offset)
649          return die_offset;
650      }
651    }
652  }
653
654  // If we're a unit DIE, also check the attributes of the dwo unit (if any).
655  if (GetParent())
656    return 0;
657  SymbolFileDWARFDwo *dwo_symbol_file = cu->GetDwoSymbolFile();
658  if (!dwo_symbol_file)
659    return 0;
660
661  DWARFCompileUnit *dwo_cu = dwo_symbol_file->GetCompileUnit();
662  if (!dwo_cu)
663    return 0;
664
665  DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly();
666  if (!dwo_cu_die.IsValid())
667    return 0;
668
669  return dwo_cu_die.GetDIE()->GetAttributeValue(
670      dwo_cu, attr, form_value, end_attr_offset_ptr,
671      check_specification_or_abstract_origin);
672}
673
674// GetAttributeValueAsString
675//
676// Get the value of an attribute as a string return it. The resulting pointer
677// to the string data exists within the supplied SymbolFileDWARF and will only
678// be available as long as the SymbolFileDWARF is still around and it's content
679// doesn't change.
680const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
681    const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
682    bool check_specification_or_abstract_origin) const {
683  DWARFFormValue form_value;
684  if (GetAttributeValue(cu, attr, form_value, nullptr,
685                        check_specification_or_abstract_origin))
686    return form_value.AsCString();
687  return fail_value;
688}
689
690// GetAttributeValueAsUnsigned
691//
692// Get the value of an attribute as unsigned and return it.
693uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
694    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
695    bool check_specification_or_abstract_origin) const {
696  DWARFFormValue form_value;
697  if (GetAttributeValue(cu, attr, form_value, nullptr,
698                        check_specification_or_abstract_origin))
699    return form_value.Unsigned();
700  return fail_value;
701}
702
703// GetAttributeValueAsReference
704//
705// Get the value of an attribute as reference and fix up and compile unit
706// relative offsets as needed.
707DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
708    const DWARFUnit *cu, const dw_attr_t attr,
709    bool check_specification_or_abstract_origin) const {
710  DWARFFormValue form_value;
711  if (GetAttributeValue(cu, attr, form_value, nullptr,
712                        check_specification_or_abstract_origin))
713    return form_value.Reference();
714  return {};
715}
716
717uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
718    const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
719    bool check_specification_or_abstract_origin) const {
720  DWARFFormValue form_value;
721  if (GetAttributeValue(cu, attr, form_value, nullptr,
722                        check_specification_or_abstract_origin))
723    return form_value.Address();
724  return fail_value;
725}
726
727// GetAttributeHighPC
728//
729// Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
730// pc>.
731//
732// Returns the hi_pc or fail_value.
733dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
734    const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
735    bool check_specification_or_abstract_origin) const {
736  DWARFFormValue form_value;
737  if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
738                        check_specification_or_abstract_origin)) {
739    dw_form_t form = form_value.Form();
740    if (form == DW_FORM_addr || form == DW_FORM_addrx ||
741        form == DW_FORM_GNU_addr_index)
742      return form_value.Address();
743
744    // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
745    return lo_pc + form_value.Unsigned();
746  }
747  return fail_value;
748}
749
750// GetAttributeAddressRange
751//
752// Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
753// from-low-pc>.
754//
755// Returns true or sets lo_pc and hi_pc to fail_value.
756bool DWARFDebugInfoEntry::GetAttributeAddressRange(
757    const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
758    uint64_t fail_value, bool check_specification_or_abstract_origin) const {
759  lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
760                                     check_specification_or_abstract_origin);
761  if (lo_pc != fail_value) {
762    hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
763                               check_specification_or_abstract_origin);
764    if (hi_pc != fail_value)
765      return true;
766  }
767  lo_pc = fail_value;
768  hi_pc = fail_value;
769  return false;
770}
771
772size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
773    const DWARFUnit *cu, DWARFRangeList &ranges, bool check_hi_lo_pc,
774    bool check_specification_or_abstract_origin) const {
775  ranges.Clear();
776
777  DWARFFormValue form_value;
778  if (GetAttributeValue(cu, DW_AT_ranges, form_value)) {
779    ranges = GetRangesOrReportError(*cu, *this, form_value);
780  } else if (check_hi_lo_pc) {
781    dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
782    dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
783    if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
784                                 check_specification_or_abstract_origin)) {
785      if (lo_pc < hi_pc)
786        ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
787    }
788  }
789  return ranges.GetSize();
790}
791
792// GetName
793//
794// Get value of the DW_AT_name attribute and return it if one exists, else
795// return NULL.
796const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
797  return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
798}
799
800// GetMangledName
801//
802// Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
803// exists, else return the value of the DW_AT_name attribute
804const char *
805DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
806                                    bool substitute_name_allowed) const {
807  const char *name = nullptr;
808
809  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
810  if (name)
811    return name;
812
813  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
814  if (name)
815    return name;
816
817  if (!substitute_name_allowed)
818    return nullptr;
819
820  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
821  return name;
822}
823
824// GetPubname
825//
826// Get value the name for a DIE as it should appear for a .debug_pubnames or
827// .debug_pubtypes section.
828const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
829  const char *name = nullptr;
830  if (!cu)
831    return name;
832
833  name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
834  if (name)
835    return name;
836
837  name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
838  if (name)
839    return name;
840
841  name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
842  return name;
843}
844
845// BuildAddressRangeTable
846void DWARFDebugInfoEntry::BuildAddressRangeTable(
847    const DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
848  if (m_tag) {
849    if (m_tag == DW_TAG_subprogram) {
850      dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
851      dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
852      if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS)) {
853        /// printf("BuildAddressRangeTable() 0x%8.8x: %30s: [0x%8.8x -
854        /// 0x%8.8x)\n", m_offset, DW_TAG_value_to_name(tag), lo_pc, hi_pc);
855        debug_aranges->AppendRange(cu->GetOffset(), lo_pc, hi_pc);
856      }
857    }
858
859    const DWARFDebugInfoEntry *child = GetFirstChild();
860    while (child) {
861      child->BuildAddressRangeTable(cu, debug_aranges);
862      child = child->GetSibling();
863    }
864  }
865}
866
867// BuildFunctionAddressRangeTable
868//
869// This function is very similar to the BuildAddressRangeTable function except
870// that the actual DIE offset for the function is placed in the table instead
871// of the compile unit offset (which is the way the standard .debug_aranges
872// section does it).
873void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
874    const DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
875  if (m_tag) {
876    if (m_tag == DW_TAG_subprogram) {
877      dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
878      dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
879      if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS)) {
880        //  printf("BuildAddressRangeTable() 0x%8.8x: [0x%16.16" PRIx64 " -
881        //  0x%16.16" PRIx64 ")\n", m_offset, lo_pc, hi_pc); // DEBUG ONLY
882        debug_aranges->AppendRange(GetOffset(), lo_pc, hi_pc);
883      }
884    }
885
886    const DWARFDebugInfoEntry *child = GetFirstChild();
887    while (child) {
888      child->BuildFunctionAddressRangeTable(cu, debug_aranges);
889      child = child->GetSibling();
890    }
891  }
892}
893
894void DWARFDebugInfoEntry::GetDWARFDeclContext(
895    DWARFUnit *cu, DWARFDeclContext &dwarf_decl_ctx) const {
896  const dw_tag_t tag = Tag();
897  if (tag != DW_TAG_compile_unit && tag != DW_TAG_partial_unit) {
898    dwarf_decl_ctx.AppendDeclContext(tag, GetName(cu));
899    DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
900    if (parent_decl_ctx_die && parent_decl_ctx_die.GetDIE() != this) {
901      if (parent_decl_ctx_die.Tag() != DW_TAG_compile_unit &&
902          parent_decl_ctx_die.Tag() != DW_TAG_partial_unit)
903        parent_decl_ctx_die.GetDIE()->GetDWARFDeclContext(
904            parent_decl_ctx_die.GetCU(), dwarf_decl_ctx);
905    }
906  }
907}
908
909DWARFDIE
910DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
911  DWARFAttributes attributes;
912  GetAttributes(cu, attributes);
913  return GetParentDeclContextDIE(cu, attributes);
914}
915
916DWARFDIE
917DWARFDebugInfoEntry::GetParentDeclContextDIE(
918    DWARFUnit *cu, const DWARFAttributes &attributes) const {
919  DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
920
921  while (die) {
922    // If this is the original DIE that we are searching for a declaration for,
923    // then don't look in the cache as we don't want our own decl context to be
924    // our decl context...
925    if (die.GetDIE() != this) {
926      switch (die.Tag()) {
927      case DW_TAG_compile_unit:
928      case DW_TAG_partial_unit:
929      case DW_TAG_namespace:
930      case DW_TAG_structure_type:
931      case DW_TAG_union_type:
932      case DW_TAG_class_type:
933        return die;
934
935      default:
936        break;
937      }
938    }
939
940    DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
941    if (spec_die) {
942      DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
943      if (decl_ctx_die)
944        return decl_ctx_die;
945    }
946
947    DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
948    if (abs_die) {
949      DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
950      if (decl_ctx_die)
951        return decl_ctx_die;
952    }
953
954    die = die.GetParent();
955  }
956  return DWARFDIE();
957}
958
959const char *DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
960                                                  std::string &storage) const {
961  DWARFAttributes attributes;
962  GetAttributes(cu, attributes);
963  return GetQualifiedName(cu, attributes, storage);
964}
965
966const char *
967DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
968                                      const DWARFAttributes &attributes,
969                                      std::string &storage) const {
970
971  const char *name = GetName(cu);
972
973  if (name) {
974    DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
975    storage.clear();
976    // TODO: change this to get the correct decl context parent....
977    while (parent_decl_ctx_die) {
978      const dw_tag_t parent_tag = parent_decl_ctx_die.Tag();
979      switch (parent_tag) {
980      case DW_TAG_namespace: {
981        const char *namespace_name = parent_decl_ctx_die.GetName();
982        if (namespace_name) {
983          storage.insert(0, "::");
984          storage.insert(0, namespace_name);
985        } else {
986          storage.insert(0, "(anonymous namespace)::");
987        }
988        parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
989      } break;
990
991      case DW_TAG_class_type:
992      case DW_TAG_structure_type:
993      case DW_TAG_union_type: {
994        const char *class_union_struct_name = parent_decl_ctx_die.GetName();
995
996        if (class_union_struct_name) {
997          storage.insert(0, "::");
998          storage.insert(0, class_union_struct_name);
999        }
1000        parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
1001      } break;
1002
1003      default:
1004        parent_decl_ctx_die.Clear();
1005        break;
1006      }
1007    }
1008
1009    if (storage.empty())
1010      storage.append("::");
1011
1012    storage.append(name);
1013  }
1014  if (storage.empty())
1015    return nullptr;
1016  return storage.c_str();
1017}
1018
1019bool DWARFDebugInfoEntry::LookupAddress(const dw_addr_t address,
1020                                        const DWARFUnit *cu,
1021                                        DWARFDebugInfoEntry **function_die,
1022                                        DWARFDebugInfoEntry **block_die) {
1023  bool found_address = false;
1024  if (m_tag) {
1025    bool check_children = false;
1026    bool match_addr_range = false;
1027    //  printf("0x%8.8x: %30s: address = 0x%8.8x - ", m_offset,
1028    //  DW_TAG_value_to_name(tag), address);
1029    switch (m_tag) {
1030    case DW_TAG_array_type:
1031      break;
1032    case DW_TAG_class_type:
1033      check_children = true;
1034      break;
1035    case DW_TAG_entry_point:
1036    case DW_TAG_enumeration_type:
1037    case DW_TAG_formal_parameter:
1038    case DW_TAG_imported_declaration:
1039    case DW_TAG_label:
1040      break;
1041    case DW_TAG_lexical_block:
1042      check_children = true;
1043      match_addr_range = true;
1044      break;
1045    case DW_TAG_member:
1046    case DW_TAG_pointer_type:
1047    case DW_TAG_reference_type:
1048      break;
1049    case DW_TAG_compile_unit:
1050      match_addr_range = true;
1051      break;
1052    case DW_TAG_string_type:
1053      break;
1054    case DW_TAG_structure_type:
1055      check_children = true;
1056      break;
1057    case DW_TAG_subroutine_type:
1058    case DW_TAG_typedef:
1059    case DW_TAG_union_type:
1060    case DW_TAG_unspecified_parameters:
1061    case DW_TAG_variant:
1062      break;
1063    case DW_TAG_common_block:
1064      check_children = true;
1065      break;
1066    case DW_TAG_common_inclusion:
1067    case DW_TAG_inheritance:
1068      break;
1069    case DW_TAG_inlined_subroutine:
1070      check_children = true;
1071      match_addr_range = true;
1072      break;
1073    case DW_TAG_module:
1074      match_addr_range = true;
1075      break;
1076    case DW_TAG_ptr_to_member_type:
1077    case DW_TAG_set_type:
1078    case DW_TAG_subrange_type:
1079    case DW_TAG_with_stmt:
1080    case DW_TAG_access_declaration:
1081    case DW_TAG_base_type:
1082      break;
1083    case DW_TAG_catch_block:
1084      match_addr_range = true;
1085      break;
1086    case DW_TAG_const_type:
1087    case DW_TAG_constant:
1088    case DW_TAG_enumerator:
1089    case DW_TAG_file_type:
1090    case DW_TAG_friend:
1091    case DW_TAG_namelist:
1092    case DW_TAG_namelist_item:
1093    case DW_TAG_packed_type:
1094      break;
1095    case DW_TAG_subprogram:
1096      match_addr_range = true;
1097      break;
1098    case DW_TAG_template_type_parameter:
1099    case DW_TAG_template_value_parameter:
1100    case DW_TAG_GNU_template_parameter_pack:
1101    case DW_TAG_thrown_type:
1102      break;
1103    case DW_TAG_try_block:
1104      match_addr_range = true;
1105      break;
1106    case DW_TAG_variant_part:
1107    case DW_TAG_variable:
1108    case DW_TAG_volatile_type:
1109    case DW_TAG_dwarf_procedure:
1110    case DW_TAG_restrict_type:
1111    case DW_TAG_interface_type:
1112      break;
1113    case DW_TAG_namespace:
1114      check_children = true;
1115      break;
1116    case DW_TAG_imported_module:
1117    case DW_TAG_unspecified_type:
1118      break;
1119    case DW_TAG_partial_unit:
1120      match_addr_range = true;
1121      break;
1122    case DW_TAG_imported_unit:
1123    case DW_TAG_shared_type:
1124    default:
1125      break;
1126    }
1127
1128    if (match_addr_range) {
1129      dw_addr_t lo_pc =
1130          GetAttributeValueAsAddress(cu, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
1131      if (lo_pc != LLDB_INVALID_ADDRESS) {
1132        dw_addr_t hi_pc = GetAttributeHighPC(cu, lo_pc, LLDB_INVALID_ADDRESS);
1133        if (hi_pc != LLDB_INVALID_ADDRESS) {
1134          //  printf("\n0x%8.8x: %30s: address = 0x%8.8x  [0x%8.8x - 0x%8.8x) ",
1135          //  m_offset, DW_TAG_value_to_name(tag), address, lo_pc, hi_pc);
1136          if ((lo_pc <= address) && (address < hi_pc)) {
1137            found_address = true;
1138            //  puts("***MATCH***");
1139            switch (m_tag) {
1140            case DW_TAG_compile_unit: // File
1141            case DW_TAG_partial_unit: // File
1142              check_children =
1143                  ((function_die != nullptr) || (block_die != nullptr));
1144              break;
1145
1146            case DW_TAG_subprogram: // Function
1147              if (function_die)
1148                *function_die = this;
1149              check_children = (block_die != nullptr);
1150              break;
1151
1152            case DW_TAG_inlined_subroutine: // Inlined Function
1153            case DW_TAG_lexical_block:      // Block { } in code
1154              if (block_die) {
1155                *block_die = this;
1156                check_children = true;
1157              }
1158              break;
1159
1160            default:
1161              check_children = true;
1162              break;
1163            }
1164          }
1165        } else {
1166          // Compile units may not have a valid high/low pc when there
1167          // are address gaps in subroutines so we must always search
1168          // if there is no valid high and low PC.
1169          check_children =
1170              (m_tag == DW_TAG_compile_unit || m_tag == DW_TAG_partial_unit) &&
1171              ((function_die != nullptr) || (block_die != nullptr));
1172        }
1173      } else {
1174        DWARFRangeList ranges;
1175        if (GetAttributeAddressRanges(cu, ranges, /*check_hi_lo_pc*/ false) &&
1176            ranges.FindEntryThatContains(address)) {
1177          found_address = true;
1178          //  puts("***MATCH***");
1179          switch (m_tag) {
1180          case DW_TAG_compile_unit: // File
1181          case DW_TAG_partial_unit: // File
1182              check_children =
1183                  ((function_die != nullptr) || (block_die != nullptr));
1184              break;
1185
1186          case DW_TAG_subprogram: // Function
1187            if (function_die)
1188              *function_die = this;
1189            check_children = (block_die != nullptr);
1190            break;
1191
1192          case DW_TAG_inlined_subroutine: // Inlined Function
1193          case DW_TAG_lexical_block:      // Block { } in code
1194            if (block_die) {
1195              *block_die = this;
1196              check_children = true;
1197            }
1198            break;
1199
1200          default:
1201            check_children = true;
1202            break;
1203          }
1204        } else {
1205          check_children = false;
1206        }
1207      }
1208    }
1209
1210    if (check_children) {
1211      //  printf("checking children\n");
1212      DWARFDebugInfoEntry *child = GetFirstChild();
1213      while (child) {
1214        if (child->LookupAddress(address, cu, function_die, block_die))
1215          return true;
1216        child = child->GetSibling();
1217      }
1218    }
1219  }
1220  return found_address;
1221}
1222
1223lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
1224  return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
1225}
1226
1227const DWARFAbbreviationDeclaration *
1228DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
1229  if (cu) {
1230    const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
1231    if (abbrev_set)
1232      return abbrev_set->GetAbbreviationDeclaration(m_abbr_idx);
1233  }
1234  return nullptr;
1235}
1236
1237bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
1238  return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
1239         m_sibling_idx == rhs.m_sibling_idx &&
1240         m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
1241         m_tag == rhs.m_tag;
1242}
1243
1244bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
1245  return !(*this == rhs);
1246}
1247