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 
33 using namespace lldb_private;
34 using namespace std;
35 extern int g_verbose;
36 
37 // Extract a debug info entry for a given DWARFUnit from the data
38 // starting at the offset in offset_ptr
39 bool DWARFDebugInfoEntry::Extract(const DWARFDataExtractor &data,
40                                   const DWARFUnit *cu,
41                                   lldb::offset_t *offset_ptr) {
42   m_offset = *offset_ptr;
43   m_parent_idx = 0;
44   m_sibling_idx = 0;
45   const uint64_t abbr_idx = data.GetULEB128(offset_ptr);
46   lldbassert(abbr_idx <= UINT16_MAX);
47   m_abbr_idx = abbr_idx;
48 
49   // assert (fixed_form_sizes);  // For best performance this should be
50   // specified!
51 
52   if (m_abbr_idx) {
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 = llvm::dwarf::DW_TAG_null;
196     m_has_children = false;
197     return true; // NULL debug tag entry
198   }
199 
200   return false;
201 }
202 
203 static DWARFRangeList GetRangesOrReportError(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.
225 bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
226     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(
344                   module, DataExtractor(data, block_offset, block_length), cu);
345             } else {
346               DataExtractor data = dwarf.DebugLocData();
347               const dw_offset_t offset = form_value.Unsigned();
348               if (data.ValidOffset(offset)) {
349                 data = DataExtractor(data, offset, data.GetByteSize() - offset);
350                 *frame_base = DWARFExpression(module, data, cu);
351                 if (lo_pc != LLDB_INVALID_ADDRESS) {
352                   assert(lo_pc >= cu->GetBaseAddress());
353                   frame_base->SetLocationListAddresses(cu->GetBaseAddress(),
354                                                        lo_pc);
355                 } else {
356                   set_frame_base_loclist_addr = true;
357                 }
358               }
359             }
360           }
361           break;
362 
363         default:
364           break;
365         }
366       }
367     }
368   }
369 
370   if (ranges.IsEmpty()) {
371     if (lo_pc != LLDB_INVALID_ADDRESS) {
372       if (hi_pc != LLDB_INVALID_ADDRESS && hi_pc > lo_pc)
373         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
374       else
375         ranges.Append(DWARFRangeList::Entry(lo_pc, 0));
376     }
377   }
378 
379   if (set_frame_base_loclist_addr) {
380     dw_addr_t lowest_range_pc = ranges.GetMinRangeBase(0);
381     assert(lowest_range_pc >= cu->GetBaseAddress());
382     frame_base->SetLocationListAddresses(cu->GetBaseAddress(), lowest_range_pc);
383   }
384 
385   if (ranges.IsEmpty() || name == nullptr || mangled == nullptr) {
386     for (const DWARFDIE &die : dies) {
387       if (die) {
388         die.GetDIE()->GetDIENamesAndRanges(die.GetCU(), name, mangled, ranges,
389                                            decl_file, decl_line, decl_column,
390                                            call_file, call_line, call_column);
391       }
392     }
393   }
394   return !ranges.IsEmpty();
395 }
396 
397 // Dump
398 //
399 // Dumps a debug information entry and all of it's attributes to the specified
400 // stream.
401 void DWARFDebugInfoEntry::Dump(const DWARFUnit *cu, Stream &s,
402                                uint32_t recurse_depth) const {
403   const DWARFDataExtractor &data = cu->GetData();
404   lldb::offset_t offset = m_offset;
405 
406   if (data.ValidOffset(offset)) {
407     dw_uleb128_t abbrCode = data.GetULEB128(&offset);
408 
409     s.Printf("\n0x%8.8x: ", m_offset);
410     s.Indent();
411     if (abbrCode != m_abbr_idx) {
412       s.Printf("error: DWARF has been modified\n");
413     } else if (abbrCode) {
414       const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
415       if (abbrevDecl) {
416         s.PutCString(DW_TAG_value_to_name(abbrevDecl->Tag()));
417         s.Printf(" [%u] %c\n", abbrCode, abbrevDecl->HasChildren() ? '*' : ' ');
418 
419         // Dump all data in the .debug_info/.debug_types for the attributes
420         const uint32_t numAttributes = abbrevDecl->NumAttributes();
421         for (uint32_t i = 0; i < numAttributes; ++i) {
422           DWARFFormValue form_value(cu);
423           dw_attr_t attr;
424           abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
425 
426           DumpAttribute(cu, data, &offset, s, attr, form_value);
427         }
428 
429         const DWARFDebugInfoEntry *child = GetFirstChild();
430         if (recurse_depth > 0 && child) {
431           s.IndentMore();
432 
433           while (child) {
434             child->Dump(cu, s, recurse_depth - 1);
435             child = child->GetSibling();
436           }
437           s.IndentLess();
438         }
439       } else
440         s.Printf("Abbreviation code note found in 'debug_abbrev' class for "
441                  "code: %u\n",
442                  abbrCode);
443     } else {
444       s.Printf("NULL\n");
445     }
446   }
447 }
448 
449 // DumpAttribute
450 //
451 // Dumps a debug information entry attribute along with it's form. Any special
452 // display of attributes is done (disassemble location lists, show enumeration
453 // values for attributes, etc).
454 void DWARFDebugInfoEntry::DumpAttribute(
455     const DWARFUnit *cu, const DWARFDataExtractor &data,
456     lldb::offset_t *offset_ptr, Stream &s, dw_attr_t attr,
457     DWARFFormValue &form_value) {
458   bool show_form = s.GetFlags().Test(DWARFDebugInfo::eDumpFlag_ShowForm);
459 
460   s.Printf("            ");
461   s.Indent(DW_AT_value_to_name(attr));
462 
463   if (show_form) {
464     s.Printf("[%s", DW_FORM_value_to_name(form_value.Form()));
465   }
466 
467   if (!form_value.ExtractValue(data, offset_ptr))
468     return;
469 
470   if (show_form) {
471     if (form_value.Form() == DW_FORM_indirect) {
472       s.Printf(" [%s]", DW_FORM_value_to_name(form_value.Form()));
473     }
474 
475     s.PutCString("] ");
476   }
477 
478   s.PutCString("( ");
479 
480   SymbolFileDWARF &dwarf = cu->GetSymbolFileDWARF();
481 
482   // Check to see if we have any special attribute formatters
483   switch (attr) {
484   case DW_AT_stmt_list:
485     s.Printf("0x%8.8" PRIx64, form_value.Unsigned());
486     break;
487 
488   case DW_AT_language:
489     s.PutCString(DW_LANG_value_to_name(form_value.Unsigned()));
490     break;
491 
492   case DW_AT_encoding:
493     s.PutCString(DW_ATE_value_to_name(form_value.Unsigned()));
494     break;
495 
496   case DW_AT_frame_base:
497   case DW_AT_location:
498   case DW_AT_data_member_location: {
499     const uint8_t *blockData = form_value.BlockData();
500     if (blockData) {
501       // Location description is inlined in data in the form value
502       DWARFDataExtractor locationData(data,
503                                       (*offset_ptr) - form_value.Unsigned(),
504                                       form_value.Unsigned());
505       DWARFExpression::PrintDWARFExpression(
506           s, locationData, DWARFUnit::GetAddressByteSize(cu), 4, false);
507     } else {
508       // We have a location list offset as the value that is the offset into
509       // the .debug_loc section that describes the value over it's lifetime
510       uint64_t debug_loc_offset = form_value.Unsigned();
511       DWARFExpression::PrintDWARFLocationList(s, cu, dwarf.DebugLocData(),
512                                               debug_loc_offset);
513     }
514   } break;
515 
516   case DW_AT_abstract_origin:
517   case DW_AT_specification: {
518     DWARFDIE abstract_die = form_value.Reference();
519     form_value.Dump(s);
520     //  *ostrm_ptr << HEX32 << abstract_die.GetOffset() << " ( ";
521     abstract_die.GetName(s);
522   } break;
523 
524   case DW_AT_type: {
525     DWARFDIE type_die = form_value.Reference();
526     s.PutCString(" ( ");
527     type_die.AppendTypeName(s);
528     s.PutCString(" )");
529   } break;
530 
531   default:
532     break;
533   }
534 
535   s.PutCString(" )\n");
536 }
537 
538 // Get all attribute values for a given DIE, including following any
539 // specification or abstract origin attributes and including those in the
540 // results. Any duplicate attributes will have the first instance take
541 // precedence (this can happen for declaration attributes).
542 size_t DWARFDebugInfoEntry::GetAttributes(
543     const DWARFUnit *cu, DWARFAttributes &attributes,
544     uint32_t curr_depth) const {
545   const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu);
546   if (abbrevDecl) {
547     const DWARFDataExtractor &data = cu->GetData();
548     lldb::offset_t offset = GetFirstAttributeOffset();
549 
550     const uint32_t num_attributes = abbrevDecl->NumAttributes();
551     for (uint32_t i = 0; i < num_attributes; ++i) {
552       DWARFFormValue form_value(cu);
553       dw_attr_t attr;
554       abbrevDecl->GetAttrAndFormValueByIndex(i, attr, form_value);
555       const dw_form_t form = form_value.Form();
556 
557       // If we are tracking down DW_AT_specification or DW_AT_abstract_origin
558       // attributes, the depth will be non-zero. We need to omit certain
559       // attributes that don't make sense.
560       switch (attr) {
561       case DW_AT_sibling:
562       case DW_AT_declaration:
563         if (curr_depth > 0) {
564           // This attribute doesn't make sense when combined with the DIE that
565           // references this DIE. We know a DIE is referencing this DIE because
566           // curr_depth is not zero
567           break;
568         }
569         LLVM_FALLTHROUGH;
570       default:
571         attributes.Append(cu, offset, attr, form);
572         break;
573       }
574 
575       if ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin)) {
576         if (form_value.ExtractValue(data, &offset)) {
577           DWARFDIE spec_die = form_value.Reference();
578           if (spec_die)
579             spec_die.GetAttributes(attributes, curr_depth + 1);
580         }
581       } else {
582         llvm::Optional<uint8_t> fixed_skip_size = DWARFFormValue::GetFixedSize(form, cu);
583         if (fixed_skip_size)
584           offset += *fixed_skip_size;
585         else
586           DWARFFormValue::SkipValue(form, data, &offset, cu);
587       }
588     }
589   } else {
590     attributes.Clear();
591   }
592   return attributes.Size();
593 }
594 
595 // GetAttributeValue
596 //
597 // Get the value of an attribute and return the .debug_info or .debug_types
598 // offset of the attribute if it was properly extracted into form_value,
599 // or zero if we fail since an offset of zero is invalid for an attribute (it
600 // would be a compile unit header).
601 dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
602     const DWARFUnit *cu, const dw_attr_t attr, DWARFFormValue &form_value,
603     dw_offset_t *end_attr_offset_ptr,
604     bool check_specification_or_abstract_origin) const {
605   if (const auto *abbrevDecl = GetAbbreviationDeclarationPtr(cu)) {
606     uint32_t attr_idx = abbrevDecl->FindAttributeIndex(attr);
607 
608     if (attr_idx != DW_INVALID_INDEX) {
609       const DWARFDataExtractor &data = cu->GetData();
610       lldb::offset_t offset = GetFirstAttributeOffset();
611 
612       uint32_t idx = 0;
613       while (idx < attr_idx)
614         DWARFFormValue::SkipValue(abbrevDecl->GetFormByIndex(idx++),
615                                   data, &offset, cu);
616 
617       const dw_offset_t attr_offset = offset;
618       form_value.SetUnit(cu);
619       form_value.SetForm(abbrevDecl->GetFormByIndex(idx));
620       if (form_value.ExtractValue(data, &offset)) {
621         if (end_attr_offset_ptr)
622           *end_attr_offset_ptr = offset;
623         return attr_offset;
624       }
625     }
626   }
627 
628   if (check_specification_or_abstract_origin) {
629     if (GetAttributeValue(cu, DW_AT_specification, form_value)) {
630       DWARFDIE die = form_value.Reference();
631       if (die) {
632         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
633             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
634         if (die_offset)
635           return die_offset;
636       }
637     }
638 
639     if (GetAttributeValue(cu, DW_AT_abstract_origin, form_value)) {
640       DWARFDIE die = form_value.Reference();
641       if (die) {
642         dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
643             die.GetCU(), attr, form_value, end_attr_offset_ptr, false);
644         if (die_offset)
645           return die_offset;
646       }
647     }
648   }
649 
650   // If we're a unit DIE, also check the attributes of the dwo unit (if any).
651   if (GetParent())
652     return 0;
653   SymbolFileDWARFDwo *dwo_symbol_file = cu->GetDwoSymbolFile();
654   if (!dwo_symbol_file)
655     return 0;
656 
657   DWARFCompileUnit *dwo_cu = dwo_symbol_file->GetCompileUnit();
658   if (!dwo_cu)
659     return 0;
660 
661   DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly();
662   if (!dwo_cu_die.IsValid())
663     return 0;
664 
665   return dwo_cu_die.GetDIE()->GetAttributeValue(
666       dwo_cu, attr, form_value, end_attr_offset_ptr,
667       check_specification_or_abstract_origin);
668 }
669 
670 // GetAttributeValueAsString
671 //
672 // Get the value of an attribute as a string return it. The resulting pointer
673 // to the string data exists within the supplied SymbolFileDWARF and will only
674 // be available as long as the SymbolFileDWARF is still around and it's content
675 // doesn't change.
676 const char *DWARFDebugInfoEntry::GetAttributeValueAsString(
677     const DWARFUnit *cu, const dw_attr_t attr, const char *fail_value,
678     bool check_specification_or_abstract_origin) const {
679   DWARFFormValue form_value;
680   if (GetAttributeValue(cu, attr, form_value, nullptr,
681                         check_specification_or_abstract_origin))
682     return form_value.AsCString();
683   return fail_value;
684 }
685 
686 // GetAttributeValueAsUnsigned
687 //
688 // Get the value of an attribute as unsigned and return it.
689 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
690     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
691     bool check_specification_or_abstract_origin) const {
692   DWARFFormValue form_value;
693   if (GetAttributeValue(cu, attr, form_value, nullptr,
694                         check_specification_or_abstract_origin))
695     return form_value.Unsigned();
696   return fail_value;
697 }
698 
699 // GetAttributeValueAsReference
700 //
701 // Get the value of an attribute as reference and fix up and compile unit
702 // relative offsets as needed.
703 DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
704     const DWARFUnit *cu, const dw_attr_t attr,
705     bool check_specification_or_abstract_origin) const {
706   DWARFFormValue form_value;
707   if (GetAttributeValue(cu, attr, form_value, nullptr,
708                         check_specification_or_abstract_origin))
709     return form_value.Reference();
710   return {};
711 }
712 
713 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
714     const DWARFUnit *cu, const dw_attr_t attr, uint64_t fail_value,
715     bool check_specification_or_abstract_origin) const {
716   DWARFFormValue form_value;
717   if (GetAttributeValue(cu, attr, form_value, nullptr,
718                         check_specification_or_abstract_origin))
719     return form_value.Address();
720   return fail_value;
721 }
722 
723 // GetAttributeHighPC
724 //
725 // Get the hi_pc, adding hi_pc to lo_pc when specified as an <offset-from-low-
726 // pc>.
727 //
728 // Returns the hi_pc or fail_value.
729 dw_addr_t DWARFDebugInfoEntry::GetAttributeHighPC(
730     const DWARFUnit *cu, dw_addr_t lo_pc, uint64_t fail_value,
731     bool check_specification_or_abstract_origin) const {
732   DWARFFormValue form_value;
733   if (GetAttributeValue(cu, DW_AT_high_pc, form_value, nullptr,
734                         check_specification_or_abstract_origin)) {
735     dw_form_t form = form_value.Form();
736     if (form == DW_FORM_addr || form == DW_FORM_addrx ||
737         form == DW_FORM_GNU_addr_index)
738       return form_value.Address();
739 
740     // DWARF4 can specify the hi_pc as an <offset-from-lowpc>
741     return lo_pc + form_value.Unsigned();
742   }
743   return fail_value;
744 }
745 
746 // GetAttributeAddressRange
747 //
748 // Get the lo_pc and hi_pc, adding hi_pc to lo_pc when specified as an <offset-
749 // from-low-pc>.
750 //
751 // Returns true or sets lo_pc and hi_pc to fail_value.
752 bool DWARFDebugInfoEntry::GetAttributeAddressRange(
753     const DWARFUnit *cu, dw_addr_t &lo_pc, dw_addr_t &hi_pc,
754     uint64_t fail_value, bool check_specification_or_abstract_origin) const {
755   lo_pc = GetAttributeValueAsAddress(cu, DW_AT_low_pc, fail_value,
756                                      check_specification_or_abstract_origin);
757   if (lo_pc != fail_value) {
758     hi_pc = GetAttributeHighPC(cu, lo_pc, fail_value,
759                                check_specification_or_abstract_origin);
760     if (hi_pc != fail_value)
761       return true;
762   }
763   lo_pc = fail_value;
764   hi_pc = fail_value;
765   return false;
766 }
767 
768 size_t DWARFDebugInfoEntry::GetAttributeAddressRanges(
769     DWARFUnit *cu, DWARFRangeList &ranges, bool check_hi_lo_pc,
770     bool check_specification_or_abstract_origin) const {
771   ranges.Clear();
772 
773   DWARFFormValue form_value;
774   if (GetAttributeValue(cu, DW_AT_ranges, form_value)) {
775     ranges = GetRangesOrReportError(*cu, *this, form_value);
776   } else if (check_hi_lo_pc) {
777     dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
778     dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
779     if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS,
780                                  check_specification_or_abstract_origin)) {
781       if (lo_pc < hi_pc)
782         ranges.Append(DWARFRangeList::Entry(lo_pc, hi_pc - lo_pc));
783     }
784   }
785   return ranges.GetSize();
786 }
787 
788 // GetName
789 //
790 // Get value of the DW_AT_name attribute and return it if one exists, else
791 // return NULL.
792 const char *DWARFDebugInfoEntry::GetName(const DWARFUnit *cu) const {
793   return GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
794 }
795 
796 // GetMangledName
797 //
798 // Get value of the DW_AT_MIPS_linkage_name attribute and return it if one
799 // exists, else return the value of the DW_AT_name attribute
800 const char *
801 DWARFDebugInfoEntry::GetMangledName(const DWARFUnit *cu,
802                                     bool substitute_name_allowed) const {
803   const char *name = nullptr;
804 
805   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
806   if (name)
807     return name;
808 
809   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
810   if (name)
811     return name;
812 
813   if (!substitute_name_allowed)
814     return nullptr;
815 
816   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
817   return name;
818 }
819 
820 // GetPubname
821 //
822 // Get value the name for a DIE as it should appear for a .debug_pubnames or
823 // .debug_pubtypes section.
824 const char *DWARFDebugInfoEntry::GetPubname(const DWARFUnit *cu) const {
825   const char *name = nullptr;
826   if (!cu)
827     return name;
828 
829   name = GetAttributeValueAsString(cu, DW_AT_MIPS_linkage_name, nullptr, true);
830   if (name)
831     return name;
832 
833   name = GetAttributeValueAsString(cu, DW_AT_linkage_name, nullptr, true);
834   if (name)
835     return name;
836 
837   name = GetAttributeValueAsString(cu, DW_AT_name, nullptr, true);
838   return name;
839 }
840 
841 // BuildAddressRangeTable
842 void DWARFDebugInfoEntry::BuildAddressRangeTable(
843     const DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
844   if (m_tag) {
845     if (m_tag == DW_TAG_subprogram) {
846       dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
847       dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
848       if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS)) {
849         /// printf("BuildAddressRangeTable() 0x%8.8x: %30s: [0x%8.8x -
850         /// 0x%8.8x)\n", m_offset, DW_TAG_value_to_name(tag), lo_pc, hi_pc);
851         debug_aranges->AppendRange(cu->GetOffset(), lo_pc, hi_pc);
852       }
853     }
854 
855     const DWARFDebugInfoEntry *child = GetFirstChild();
856     while (child) {
857       child->BuildAddressRangeTable(cu, debug_aranges);
858       child = child->GetSibling();
859     }
860   }
861 }
862 
863 // BuildFunctionAddressRangeTable
864 //
865 // This function is very similar to the BuildAddressRangeTable function except
866 // that the actual DIE offset for the function is placed in the table instead
867 // of the compile unit offset (which is the way the standard .debug_aranges
868 // section does it).
869 void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
870     const DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
871   if (m_tag) {
872     if (m_tag == DW_TAG_subprogram) {
873       dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
874       dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
875       if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS)) {
876         //  printf("BuildAddressRangeTable() 0x%8.8x: [0x%16.16" PRIx64 " -
877         //  0x%16.16" PRIx64 ")\n", m_offset, lo_pc, hi_pc); // DEBUG ONLY
878         debug_aranges->AppendRange(GetOffset(), lo_pc, hi_pc);
879       }
880     }
881 
882     const DWARFDebugInfoEntry *child = GetFirstChild();
883     while (child) {
884       child->BuildFunctionAddressRangeTable(cu, debug_aranges);
885       child = child->GetSibling();
886     }
887   }
888 }
889 
890 void DWARFDebugInfoEntry::GetDWARFDeclContext(
891     DWARFUnit *cu, DWARFDeclContext &dwarf_decl_ctx) const {
892   const dw_tag_t tag = Tag();
893   if (tag != DW_TAG_compile_unit && tag != DW_TAG_partial_unit) {
894     dwarf_decl_ctx.AppendDeclContext(tag, GetName(cu));
895     DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
896     if (parent_decl_ctx_die && parent_decl_ctx_die.GetDIE() != this) {
897       if (parent_decl_ctx_die.Tag() != DW_TAG_compile_unit &&
898           parent_decl_ctx_die.Tag() != DW_TAG_partial_unit)
899         parent_decl_ctx_die.GetDIE()->GetDWARFDeclContext(
900             parent_decl_ctx_die.GetCU(), dwarf_decl_ctx);
901     }
902   }
903 }
904 
905 DWARFDIE
906 DWARFDebugInfoEntry::GetParentDeclContextDIE(DWARFUnit *cu) const {
907   DWARFAttributes attributes;
908   GetAttributes(cu, attributes);
909   return GetParentDeclContextDIE(cu, attributes);
910 }
911 
912 DWARFDIE
913 DWARFDebugInfoEntry::GetParentDeclContextDIE(
914     DWARFUnit *cu, const DWARFAttributes &attributes) const {
915   DWARFDIE die(cu, const_cast<DWARFDebugInfoEntry *>(this));
916 
917   while (die) {
918     // If this is the original DIE that we are searching for a declaration for,
919     // then don't look in the cache as we don't want our own decl context to be
920     // our decl context...
921     if (die.GetDIE() != this) {
922       switch (die.Tag()) {
923       case DW_TAG_compile_unit:
924       case DW_TAG_partial_unit:
925       case DW_TAG_namespace:
926       case DW_TAG_structure_type:
927       case DW_TAG_union_type:
928       case DW_TAG_class_type:
929         return die;
930 
931       default:
932         break;
933       }
934     }
935 
936     DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
937     if (spec_die) {
938       DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
939       if (decl_ctx_die)
940         return decl_ctx_die;
941     }
942 
943     DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
944     if (abs_die) {
945       DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
946       if (decl_ctx_die)
947         return decl_ctx_die;
948     }
949 
950     die = die.GetParent();
951   }
952   return DWARFDIE();
953 }
954 
955 const char *DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
956                                                   std::string &storage) const {
957   DWARFAttributes attributes;
958   GetAttributes(cu, attributes);
959   return GetQualifiedName(cu, attributes, storage);
960 }
961 
962 const char *
963 DWARFDebugInfoEntry::GetQualifiedName(DWARFUnit *cu,
964                                       const DWARFAttributes &attributes,
965                                       std::string &storage) const {
966 
967   const char *name = GetName(cu);
968 
969   if (name) {
970     DWARFDIE parent_decl_ctx_die = GetParentDeclContextDIE(cu);
971     storage.clear();
972     // TODO: change this to get the correct decl context parent....
973     while (parent_decl_ctx_die) {
974       const dw_tag_t parent_tag = parent_decl_ctx_die.Tag();
975       switch (parent_tag) {
976       case DW_TAG_namespace: {
977         const char *namespace_name = parent_decl_ctx_die.GetName();
978         if (namespace_name) {
979           storage.insert(0, "::");
980           storage.insert(0, namespace_name);
981         } else {
982           storage.insert(0, "(anonymous namespace)::");
983         }
984         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
985       } break;
986 
987       case DW_TAG_class_type:
988       case DW_TAG_structure_type:
989       case DW_TAG_union_type: {
990         const char *class_union_struct_name = parent_decl_ctx_die.GetName();
991 
992         if (class_union_struct_name) {
993           storage.insert(0, "::");
994           storage.insert(0, class_union_struct_name);
995         }
996         parent_decl_ctx_die = parent_decl_ctx_die.GetParentDeclContextDIE();
997       } break;
998 
999       default:
1000         parent_decl_ctx_die.Clear();
1001         break;
1002       }
1003     }
1004 
1005     if (storage.empty())
1006       storage.append("::");
1007 
1008     storage.append(name);
1009   }
1010   if (storage.empty())
1011     return nullptr;
1012   return storage.c_str();
1013 }
1014 
1015 bool DWARFDebugInfoEntry::LookupAddress(const dw_addr_t address, DWARFUnit *cu,
1016                                         DWARFDebugInfoEntry **function_die,
1017                                         DWARFDebugInfoEntry **block_die) {
1018   bool found_address = false;
1019   if (m_tag) {
1020     bool check_children = false;
1021     bool match_addr_range = false;
1022     //  printf("0x%8.8x: %30s: address = 0x%8.8x - ", m_offset,
1023     //  DW_TAG_value_to_name(tag), address);
1024     switch (m_tag) {
1025     case DW_TAG_array_type:
1026       break;
1027     case DW_TAG_class_type:
1028       check_children = true;
1029       break;
1030     case DW_TAG_entry_point:
1031     case DW_TAG_enumeration_type:
1032     case DW_TAG_formal_parameter:
1033     case DW_TAG_imported_declaration:
1034     case DW_TAG_label:
1035       break;
1036     case DW_TAG_lexical_block:
1037       check_children = true;
1038       match_addr_range = true;
1039       break;
1040     case DW_TAG_member:
1041     case DW_TAG_pointer_type:
1042     case DW_TAG_reference_type:
1043       break;
1044     case DW_TAG_compile_unit:
1045       match_addr_range = true;
1046       break;
1047     case DW_TAG_string_type:
1048       break;
1049     case DW_TAG_structure_type:
1050       check_children = true;
1051       break;
1052     case DW_TAG_subroutine_type:
1053     case DW_TAG_typedef:
1054     case DW_TAG_union_type:
1055     case DW_TAG_unspecified_parameters:
1056     case DW_TAG_variant:
1057       break;
1058     case DW_TAG_common_block:
1059       check_children = true;
1060       break;
1061     case DW_TAG_common_inclusion:
1062     case DW_TAG_inheritance:
1063       break;
1064     case DW_TAG_inlined_subroutine:
1065       check_children = true;
1066       match_addr_range = true;
1067       break;
1068     case DW_TAG_module:
1069       match_addr_range = true;
1070       break;
1071     case DW_TAG_ptr_to_member_type:
1072     case DW_TAG_set_type:
1073     case DW_TAG_subrange_type:
1074     case DW_TAG_with_stmt:
1075     case DW_TAG_access_declaration:
1076     case DW_TAG_base_type:
1077       break;
1078     case DW_TAG_catch_block:
1079       match_addr_range = true;
1080       break;
1081     case DW_TAG_const_type:
1082     case DW_TAG_constant:
1083     case DW_TAG_enumerator:
1084     case DW_TAG_file_type:
1085     case DW_TAG_friend:
1086     case DW_TAG_namelist:
1087     case DW_TAG_namelist_item:
1088     case DW_TAG_packed_type:
1089       break;
1090     case DW_TAG_subprogram:
1091       match_addr_range = true;
1092       break;
1093     case DW_TAG_template_type_parameter:
1094     case DW_TAG_template_value_parameter:
1095     case DW_TAG_GNU_template_parameter_pack:
1096     case DW_TAG_thrown_type:
1097       break;
1098     case DW_TAG_try_block:
1099       match_addr_range = true;
1100       break;
1101     case DW_TAG_variant_part:
1102     case DW_TAG_variable:
1103     case DW_TAG_volatile_type:
1104     case DW_TAG_dwarf_procedure:
1105     case DW_TAG_restrict_type:
1106     case DW_TAG_interface_type:
1107       break;
1108     case DW_TAG_namespace:
1109       check_children = true;
1110       break;
1111     case DW_TAG_imported_module:
1112     case DW_TAG_unspecified_type:
1113       break;
1114     case DW_TAG_partial_unit:
1115       match_addr_range = true;
1116       break;
1117     case DW_TAG_imported_unit:
1118     case DW_TAG_shared_type:
1119     default:
1120       break;
1121     }
1122 
1123     if (match_addr_range) {
1124       dw_addr_t lo_pc =
1125           GetAttributeValueAsAddress(cu, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
1126       if (lo_pc != LLDB_INVALID_ADDRESS) {
1127         dw_addr_t hi_pc = GetAttributeHighPC(cu, lo_pc, LLDB_INVALID_ADDRESS);
1128         if (hi_pc != LLDB_INVALID_ADDRESS) {
1129           //  printf("\n0x%8.8x: %30s: address = 0x%8.8x  [0x%8.8x - 0x%8.8x) ",
1130           //  m_offset, DW_TAG_value_to_name(tag), address, lo_pc, hi_pc);
1131           if ((lo_pc <= address) && (address < hi_pc)) {
1132             found_address = true;
1133             //  puts("***MATCH***");
1134             switch (m_tag) {
1135             case DW_TAG_compile_unit: // File
1136             case DW_TAG_partial_unit: // File
1137               check_children =
1138                   ((function_die != nullptr) || (block_die != nullptr));
1139               break;
1140 
1141             case DW_TAG_subprogram: // Function
1142               if (function_die)
1143                 *function_die = this;
1144               check_children = (block_die != nullptr);
1145               break;
1146 
1147             case DW_TAG_inlined_subroutine: // Inlined Function
1148             case DW_TAG_lexical_block:      // Block { } in code
1149               if (block_die) {
1150                 *block_die = this;
1151                 check_children = true;
1152               }
1153               break;
1154 
1155             default:
1156               check_children = true;
1157               break;
1158             }
1159           }
1160         } else {
1161           // Compile units may not have a valid high/low pc when there
1162           // are address gaps in subroutines so we must always search
1163           // if there is no valid high and low PC.
1164           check_children =
1165               (m_tag == DW_TAG_compile_unit || m_tag == DW_TAG_partial_unit) &&
1166               ((function_die != nullptr) || (block_die != nullptr));
1167         }
1168       } else {
1169         DWARFRangeList ranges;
1170         if (GetAttributeAddressRanges(cu, ranges, /*check_hi_lo_pc*/ false) &&
1171             ranges.FindEntryThatContains(address)) {
1172           found_address = true;
1173           //  puts("***MATCH***");
1174           switch (m_tag) {
1175           case DW_TAG_compile_unit: // File
1176           case DW_TAG_partial_unit: // File
1177               check_children =
1178                   ((function_die != nullptr) || (block_die != nullptr));
1179               break;
1180 
1181           case DW_TAG_subprogram: // Function
1182             if (function_die)
1183               *function_die = this;
1184             check_children = (block_die != nullptr);
1185             break;
1186 
1187           case DW_TAG_inlined_subroutine: // Inlined Function
1188           case DW_TAG_lexical_block:      // Block { } in code
1189             if (block_die) {
1190               *block_die = this;
1191               check_children = true;
1192             }
1193             break;
1194 
1195           default:
1196             check_children = true;
1197             break;
1198           }
1199         } else {
1200           check_children = false;
1201         }
1202       }
1203     }
1204 
1205     if (check_children) {
1206       //  printf("checking children\n");
1207       DWARFDebugInfoEntry *child = GetFirstChild();
1208       while (child) {
1209         if (child->LookupAddress(address, cu, function_die, block_die))
1210           return true;
1211         child = child->GetSibling();
1212       }
1213     }
1214   }
1215   return found_address;
1216 }
1217 
1218 lldb::offset_t DWARFDebugInfoEntry::GetFirstAttributeOffset() const {
1219   return GetOffset() + llvm::getULEB128Size(m_abbr_idx);
1220 }
1221 
1222 const DWARFAbbreviationDeclaration *
1223 DWARFDebugInfoEntry::GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const {
1224   if (cu) {
1225     const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
1226     if (abbrev_set)
1227       return abbrev_set->GetAbbreviationDeclaration(m_abbr_idx);
1228   }
1229   return nullptr;
1230 }
1231 
1232 bool DWARFDebugInfoEntry::operator==(const DWARFDebugInfoEntry &rhs) const {
1233   return m_offset == rhs.m_offset && m_parent_idx == rhs.m_parent_idx &&
1234          m_sibling_idx == rhs.m_sibling_idx &&
1235          m_abbr_idx == rhs.m_abbr_idx && m_has_children == rhs.m_has_children &&
1236          m_tag == rhs.m_tag;
1237 }
1238 
1239 bool DWARFDebugInfoEntry::operator!=(const DWARFDebugInfoEntry &rhs) const {
1240   return !(*this == rhs);
1241 }
1242