1 //===-- SymbolFileDWARF.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 "SymbolFileDWARF.h"
10 
11 #include "llvm/ADT/Optional.h"
12 #include "llvm/Support/Casting.h"
13 #include "llvm/Support/Threading.h"
14 
15 #include "lldb/Core/Module.h"
16 #include "lldb/Core/ModuleList.h"
17 #include "lldb/Core/ModuleSpec.h"
18 #include "lldb/Core/PluginManager.h"
19 #include "lldb/Core/Section.h"
20 #include "lldb/Core/StreamFile.h"
21 #include "lldb/Core/Value.h"
22 #include "lldb/Utility/ArchSpec.h"
23 #include "lldb/Utility/RegularExpression.h"
24 #include "lldb/Utility/Scalar.h"
25 #include "lldb/Utility/StreamString.h"
26 #include "lldb/Utility/Timer.h"
27 
28 #include "Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.h"
29 #include "Plugins/Language/CPlusPlus/CPlusPlusLanguage.h"
30 
31 #include "lldb/Host/FileSystem.h"
32 #include "lldb/Host/Host.h"
33 
34 #include "lldb/Interpreter/OptionValueFileSpecList.h"
35 #include "lldb/Interpreter/OptionValueProperties.h"
36 
37 #include "lldb/Symbol/Block.h"
38 #include "lldb/Symbol/ClangASTContext.h"
39 #include "lldb/Symbol/ClangUtil.h"
40 #include "lldb/Symbol/CompileUnit.h"
41 #include "lldb/Symbol/CompilerDecl.h"
42 #include "lldb/Symbol/CompilerDeclContext.h"
43 #include "lldb/Symbol/DebugMacros.h"
44 #include "lldb/Symbol/LineTable.h"
45 #include "lldb/Symbol/LocateSymbolFile.h"
46 #include "lldb/Symbol/ObjectFile.h"
47 #include "lldb/Symbol/SymbolFile.h"
48 #include "lldb/Symbol/TypeMap.h"
49 #include "lldb/Symbol/TypeSystem.h"
50 #include "lldb/Symbol/VariableList.h"
51 
52 #include "lldb/Target/Language.h"
53 #include "lldb/Target/Target.h"
54 
55 #include "AppleDWARFIndex.h"
56 #include "DWARFASTParser.h"
57 #include "DWARFASTParserClang.h"
58 #include "DWARFCompileUnit.h"
59 #include "DWARFDebugAbbrev.h"
60 #include "DWARFDebugAranges.h"
61 #include "DWARFDebugInfo.h"
62 #include "DWARFDebugMacro.h"
63 #include "DWARFDebugRanges.h"
64 #include "DWARFDeclContext.h"
65 #include "DWARFFormValue.h"
66 #include "DWARFTypeUnit.h"
67 #include "DWARFUnit.h"
68 #include "DebugNamesDWARFIndex.h"
69 #include "LogChannelDWARF.h"
70 #include "ManualDWARFIndex.h"
71 #include "SymbolFileDWARFDebugMap.h"
72 #include "SymbolFileDWARFDwo.h"
73 #include "SymbolFileDWARFDwp.h"
74 
75 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
76 #include "llvm/Support/FileSystem.h"
77 
78 #include <algorithm>
79 #include <map>
80 #include <memory>
81 
82 #include <ctype.h>
83 #include <string.h>
84 
85 //#define ENABLE_DEBUG_PRINTF // COMMENT OUT THIS LINE PRIOR TO CHECKIN
86 
87 #ifdef ENABLE_DEBUG_PRINTF
88 #include <stdio.h>
89 #define DEBUG_PRINTF(fmt, ...) printf(fmt, __VA_ARGS__)
90 #else
91 #define DEBUG_PRINTF(fmt, ...)
92 #endif
93 
94 using namespace lldb;
95 using namespace lldb_private;
96 
97 char SymbolFileDWARF::ID;
98 
99 // static inline bool
100 // child_requires_parent_class_union_or_struct_to_be_completed (dw_tag_t tag)
101 //{
102 //    switch (tag)
103 //    {
104 //    default:
105 //        break;
106 //    case DW_TAG_subprogram:
107 //    case DW_TAG_inlined_subroutine:
108 //    case DW_TAG_class_type:
109 //    case DW_TAG_structure_type:
110 //    case DW_TAG_union_type:
111 //        return true;
112 //    }
113 //    return false;
114 //}
115 //
116 
117 namespace {
118 
119 #define LLDB_PROPERTIES_symbolfiledwarf
120 #include "SymbolFileDWARFProperties.inc"
121 
122 enum {
123 #define LLDB_PROPERTIES_symbolfiledwarf
124 #include "SymbolFileDWARFPropertiesEnum.inc"
125 };
126 
127 class PluginProperties : public Properties {
128 public:
129   static ConstString GetSettingName() {
130     return SymbolFileDWARF::GetPluginNameStatic();
131   }
132 
133   PluginProperties() {
134     m_collection_sp = std::make_shared<OptionValueProperties>(GetSettingName());
135     m_collection_sp->Initialize(g_symbolfiledwarf_properties);
136   }
137 
138   FileSpecList GetSymLinkPaths() {
139     const OptionValueFileSpecList *option_value =
140         m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpecList(
141             nullptr, true, ePropertySymLinkPaths);
142     assert(option_value);
143     return option_value->GetCurrentValue();
144   }
145 
146   bool IgnoreFileIndexes() const {
147     return m_collection_sp->GetPropertyAtIndexAsBoolean(
148         nullptr, ePropertyIgnoreIndexes, false);
149   }
150 };
151 
152 typedef std::shared_ptr<PluginProperties> SymbolFileDWARFPropertiesSP;
153 
154 static const SymbolFileDWARFPropertiesSP &GetGlobalPluginProperties() {
155   static const auto g_settings_sp(std::make_shared<PluginProperties>());
156   return g_settings_sp;
157 }
158 
159 } // namespace
160 
161 static const llvm::DWARFDebugLine::LineTable *
162 ParseLLVMLineTable(lldb_private::DWARFContext &context,
163                    llvm::DWARFDebugLine &line, dw_offset_t line_offset,
164                    dw_offset_t unit_offset) {
165   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
166 
167   llvm::DWARFDataExtractor data = context.getOrLoadLineData().GetAsLLVM();
168   llvm::DWARFContext &ctx = context.GetAsLLVM();
169   llvm::Expected<const llvm::DWARFDebugLine::LineTable *> line_table =
170       line.getOrParseLineTable(
171           data, line_offset, ctx, nullptr, [&](llvm::Error e) {
172             LLDB_LOG_ERROR(log, std::move(e),
173                            "SymbolFileDWARF::ParseLineTable failed to parse");
174           });
175 
176   if (!line_table) {
177     LLDB_LOG_ERROR(log, line_table.takeError(),
178                    "SymbolFileDWARF::ParseLineTable failed to parse");
179     return nullptr;
180   }
181   return *line_table;
182 }
183 
184 static llvm::Optional<std::string>
185 GetFileByIndex(const llvm::DWARFDebugLine::Prologue &prologue, size_t idx,
186                llvm::StringRef compile_dir, FileSpec::Style style) {
187   // Try to get an absolute path first.
188   std::string abs_path;
189   auto absolute = llvm::DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath;
190   if (prologue.getFileNameByIndex(idx, compile_dir, absolute, abs_path, style))
191     return std::move(abs_path);
192 
193   // Otherwise ask for a relative path.
194   std::string rel_path;
195   auto relative = llvm::DILineInfoSpecifier::FileLineInfoKind::Default;
196   if (!prologue.getFileNameByIndex(idx, compile_dir, relative, rel_path, style))
197     return {};
198   return std::move(rel_path);
199 }
200 
201 static FileSpecList
202 ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
203                               const llvm::DWARFDebugLine::Prologue &prologue,
204                               FileSpec::Style style,
205                               llvm::StringRef compile_dir = {}) {
206   FileSpecList support_files;
207   size_t first_file = 0;
208   if (prologue.getVersion() <= 4) {
209     // File index 0 is not valid before DWARF v5. Add a dummy entry to ensure
210     // support file list indices match those we get from the debug info and line
211     // tables.
212     support_files.Append(FileSpec());
213     first_file = 1;
214   }
215 
216   const size_t number_of_files = prologue.FileNames.size();
217   for (size_t idx = first_file; idx <= number_of_files; ++idx) {
218     std::string remapped_file;
219     if (auto file_path = GetFileByIndex(prologue, idx, compile_dir, style))
220       if (!module->RemapSourceFile(llvm::StringRef(*file_path), remapped_file))
221         remapped_file = std::move(*file_path);
222 
223     // Unconditionally add an entry, so the indices match up.
224     support_files.EmplaceBack(remapped_file, style);
225   }
226 
227   return support_files;
228 }
229 
230 FileSpecList SymbolFileDWARF::GetSymlinkPaths() {
231   return GetGlobalPluginProperties()->GetSymLinkPaths();
232 }
233 
234 void SymbolFileDWARF::Initialize() {
235   LogChannelDWARF::Initialize();
236   PluginManager::RegisterPlugin(GetPluginNameStatic(),
237                                 GetPluginDescriptionStatic(), CreateInstance,
238                                 DebuggerInitialize);
239 }
240 
241 void SymbolFileDWARF::DebuggerInitialize(Debugger &debugger) {
242   if (!PluginManager::GetSettingForSymbolFilePlugin(
243           debugger, PluginProperties::GetSettingName())) {
244     const bool is_global_setting = true;
245     PluginManager::CreateSettingForSymbolFilePlugin(
246         debugger, GetGlobalPluginProperties()->GetValueProperties(),
247         ConstString("Properties for the dwarf symbol-file plug-in."),
248         is_global_setting);
249   }
250 }
251 
252 void SymbolFileDWARF::Terminate() {
253   PluginManager::UnregisterPlugin(CreateInstance);
254   LogChannelDWARF::Terminate();
255 }
256 
257 lldb_private::ConstString SymbolFileDWARF::GetPluginNameStatic() {
258   static ConstString g_name("dwarf");
259   return g_name;
260 }
261 
262 const char *SymbolFileDWARF::GetPluginDescriptionStatic() {
263   return "DWARF and DWARF3 debug symbol file reader.";
264 }
265 
266 SymbolFile *SymbolFileDWARF::CreateInstance(ObjectFileSP objfile_sp) {
267   return new SymbolFileDWARF(std::move(objfile_sp),
268                              /*dwo_section_list*/ nullptr);
269 }
270 
271 TypeList &SymbolFileDWARF::GetTypeList() {
272   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
273   if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile())
274     return debug_map_symfile->GetTypeList();
275   return SymbolFile::GetTypeList();
276 }
277 void SymbolFileDWARF::GetTypes(const DWARFDIE &die, dw_offset_t min_die_offset,
278                                dw_offset_t max_die_offset, uint32_t type_mask,
279                                TypeSet &type_set) {
280   if (die) {
281     const dw_offset_t die_offset = die.GetOffset();
282 
283     if (die_offset >= max_die_offset)
284       return;
285 
286     if (die_offset >= min_die_offset) {
287       const dw_tag_t tag = die.Tag();
288 
289       bool add_type = false;
290 
291       switch (tag) {
292       case DW_TAG_array_type:
293         add_type = (type_mask & eTypeClassArray) != 0;
294         break;
295       case DW_TAG_unspecified_type:
296       case DW_TAG_base_type:
297         add_type = (type_mask & eTypeClassBuiltin) != 0;
298         break;
299       case DW_TAG_class_type:
300         add_type = (type_mask & eTypeClassClass) != 0;
301         break;
302       case DW_TAG_structure_type:
303         add_type = (type_mask & eTypeClassStruct) != 0;
304         break;
305       case DW_TAG_union_type:
306         add_type = (type_mask & eTypeClassUnion) != 0;
307         break;
308       case DW_TAG_enumeration_type:
309         add_type = (type_mask & eTypeClassEnumeration) != 0;
310         break;
311       case DW_TAG_subroutine_type:
312       case DW_TAG_subprogram:
313       case DW_TAG_inlined_subroutine:
314         add_type = (type_mask & eTypeClassFunction) != 0;
315         break;
316       case DW_TAG_pointer_type:
317         add_type = (type_mask & eTypeClassPointer) != 0;
318         break;
319       case DW_TAG_rvalue_reference_type:
320       case DW_TAG_reference_type:
321         add_type = (type_mask & eTypeClassReference) != 0;
322         break;
323       case DW_TAG_typedef:
324         add_type = (type_mask & eTypeClassTypedef) != 0;
325         break;
326       case DW_TAG_ptr_to_member_type:
327         add_type = (type_mask & eTypeClassMemberPointer) != 0;
328         break;
329       default:
330         break;
331       }
332 
333       if (add_type) {
334         const bool assert_not_being_parsed = true;
335         Type *type = ResolveTypeUID(die, assert_not_being_parsed);
336         if (type) {
337           if (type_set.find(type) == type_set.end())
338             type_set.insert(type);
339         }
340       }
341     }
342 
343     for (DWARFDIE child_die = die.GetFirstChild(); child_die.IsValid();
344          child_die = child_die.GetSibling()) {
345       GetTypes(child_die, min_die_offset, max_die_offset, type_mask, type_set);
346     }
347   }
348 }
349 
350 void SymbolFileDWARF::GetTypes(SymbolContextScope *sc_scope,
351                                TypeClass type_mask, TypeList &type_list)
352 
353 {
354   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
355   TypeSet type_set;
356 
357   CompileUnit *comp_unit = nullptr;
358   DWARFUnit *dwarf_cu = nullptr;
359   if (sc_scope)
360     comp_unit = sc_scope->CalculateSymbolContextCompileUnit();
361 
362   if (comp_unit) {
363     dwarf_cu = GetDWARFCompileUnit(comp_unit);
364     if (!dwarf_cu)
365       return;
366     GetTypes(dwarf_cu->DIE(), dwarf_cu->GetOffset(),
367              dwarf_cu->GetNextUnitOffset(), type_mask, type_set);
368   } else {
369     DWARFDebugInfo *info = DebugInfo();
370     if (info) {
371       const size_t num_cus = info->GetNumUnits();
372       for (size_t cu_idx = 0; cu_idx < num_cus; ++cu_idx) {
373         dwarf_cu = info->GetUnitAtIndex(cu_idx);
374         if (dwarf_cu) {
375           GetTypes(dwarf_cu->DIE(), 0, UINT32_MAX, type_mask, type_set);
376         }
377       }
378     }
379   }
380 
381   std::set<CompilerType> compiler_type_set;
382   for (Type *type : type_set) {
383     CompilerType compiler_type = type->GetForwardCompilerType();
384     if (compiler_type_set.find(compiler_type) == compiler_type_set.end()) {
385       compiler_type_set.insert(compiler_type);
386       type_list.Insert(type->shared_from_this());
387     }
388   }
389 }
390 
391 // Gets the first parent that is a lexical block, function or inlined
392 // subroutine, or compile unit.
393 DWARFDIE
394 SymbolFileDWARF::GetParentSymbolContextDIE(const DWARFDIE &child_die) {
395   DWARFDIE die;
396   for (die = child_die.GetParent(); die; die = die.GetParent()) {
397     dw_tag_t tag = die.Tag();
398 
399     switch (tag) {
400     case DW_TAG_compile_unit:
401     case DW_TAG_partial_unit:
402     case DW_TAG_subprogram:
403     case DW_TAG_inlined_subroutine:
404     case DW_TAG_lexical_block:
405       return die;
406     default:
407       break;
408     }
409   }
410   return DWARFDIE();
411 }
412 
413 SymbolFileDWARF::SymbolFileDWARF(ObjectFileSP objfile_sp,
414                                  SectionList *dwo_section_list)
415     : SymbolFile(std::move(objfile_sp)),
416       UserID(0x7fffffff00000000), // Used by SymbolFileDWARFDebugMap to
417                                   // when this class parses .o files to
418                                   // contain the .o file index/ID
419       m_debug_map_module_wp(), m_debug_map_symfile(nullptr),
420       m_context(m_objfile_sp->GetModule()->GetSectionList(), dwo_section_list),
421       m_data_debug_loc(), m_abbr(), m_info(), m_fetched_external_modules(false),
422       m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate),
423       m_unique_ast_type_map() {}
424 
425 SymbolFileDWARF::~SymbolFileDWARF() {}
426 
427 static ConstString GetDWARFMachOSegmentName() {
428   static ConstString g_dwarf_section_name("__DWARF");
429   return g_dwarf_section_name;
430 }
431 
432 UniqueDWARFASTTypeMap &SymbolFileDWARF::GetUniqueDWARFASTTypeMap() {
433   SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
434   if (debug_map_symfile)
435     return debug_map_symfile->GetUniqueDWARFASTTypeMap();
436   else
437     return m_unique_ast_type_map;
438 }
439 
440 llvm::Expected<TypeSystem &>
441 SymbolFileDWARF::GetTypeSystemForLanguage(LanguageType language) {
442   if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile())
443     return debug_map_symfile->GetTypeSystemForLanguage(language);
444 
445   auto type_system_or_err =
446       m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
447   if (type_system_or_err) {
448     type_system_or_err->SetSymbolFile(this);
449   }
450   return type_system_or_err;
451 }
452 
453 void SymbolFileDWARF::InitializeObject() {
454   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
455 
456   if (!GetGlobalPluginProperties()->IgnoreFileIndexes()) {
457     DWARFDataExtractor apple_names, apple_namespaces, apple_types, apple_objc;
458     LoadSectionData(eSectionTypeDWARFAppleNames, apple_names);
459     LoadSectionData(eSectionTypeDWARFAppleNamespaces, apple_namespaces);
460     LoadSectionData(eSectionTypeDWARFAppleTypes, apple_types);
461     LoadSectionData(eSectionTypeDWARFAppleObjC, apple_objc);
462 
463     m_index = AppleDWARFIndex::Create(
464         *GetObjectFile()->GetModule(), apple_names, apple_namespaces,
465         apple_types, apple_objc, m_context.getOrLoadStrData());
466 
467     if (m_index)
468       return;
469 
470     DWARFDataExtractor debug_names;
471     LoadSectionData(eSectionTypeDWARFDebugNames, debug_names);
472     if (debug_names.GetByteSize() > 0) {
473       llvm::Expected<std::unique_ptr<DebugNamesDWARFIndex>> index_or =
474           DebugNamesDWARFIndex::Create(
475               *GetObjectFile()->GetModule(), debug_names,
476               m_context.getOrLoadStrData(), DebugInfo());
477       if (index_or) {
478         m_index = std::move(*index_or);
479         return;
480       }
481       LLDB_LOG_ERROR(log, index_or.takeError(),
482                      "Unable to read .debug_names data: {0}");
483     }
484   }
485 
486   m_index = std::make_unique<ManualDWARFIndex>(*GetObjectFile()->GetModule(),
487                                                 DebugInfo());
488 }
489 
490 bool SymbolFileDWARF::SupportedVersion(uint16_t version) {
491   return version >= 2 && version <= 5;
492 }
493 
494 uint32_t SymbolFileDWARF::CalculateAbilities() {
495   uint32_t abilities = 0;
496   if (m_objfile_sp != nullptr) {
497     const Section *section = nullptr;
498     const SectionList *section_list = m_objfile_sp->GetSectionList();
499     if (section_list == nullptr)
500       return 0;
501 
502     uint64_t debug_abbrev_file_size = 0;
503     uint64_t debug_info_file_size = 0;
504     uint64_t debug_line_file_size = 0;
505 
506     section = section_list->FindSectionByName(GetDWARFMachOSegmentName()).get();
507 
508     if (section)
509       section_list = &section->GetChildren();
510 
511     section =
512         section_list->FindSectionByType(eSectionTypeDWARFDebugInfo, true).get();
513     if (section != nullptr) {
514       debug_info_file_size = section->GetFileSize();
515 
516       section =
517           section_list->FindSectionByType(eSectionTypeDWARFDebugAbbrev, true)
518               .get();
519       if (section)
520         debug_abbrev_file_size = section->GetFileSize();
521 
522       DWARFDebugAbbrev *abbrev = DebugAbbrev();
523       if (abbrev) {
524         std::set<dw_form_t> invalid_forms;
525         abbrev->GetUnsupportedForms(invalid_forms);
526         if (!invalid_forms.empty()) {
527           StreamString error;
528           error.Printf("unsupported DW_FORM value%s:",
529                        invalid_forms.size() > 1 ? "s" : "");
530           for (auto form : invalid_forms)
531             error.Printf(" %#x", form);
532           m_objfile_sp->GetModule()->ReportWarning(
533               "%s", error.GetString().str().c_str());
534           return 0;
535         }
536       }
537 
538       section =
539           section_list->FindSectionByType(eSectionTypeDWARFDebugLine, true)
540               .get();
541       if (section)
542         debug_line_file_size = section->GetFileSize();
543     } else {
544       const char *symfile_dir_cstr =
545           m_objfile_sp->GetFileSpec().GetDirectory().GetCString();
546       if (symfile_dir_cstr) {
547         if (strcasestr(symfile_dir_cstr, ".dsym")) {
548           if (m_objfile_sp->GetType() == ObjectFile::eTypeDebugInfo) {
549             // We have a dSYM file that didn't have a any debug info. If the
550             // string table has a size of 1, then it was made from an
551             // executable with no debug info, or from an executable that was
552             // stripped.
553             section =
554                 section_list->FindSectionByType(eSectionTypeDWARFDebugStr, true)
555                     .get();
556             if (section && section->GetFileSize() == 1) {
557               m_objfile_sp->GetModule()->ReportWarning(
558                   "empty dSYM file detected, dSYM was created with an "
559                   "executable with no debug info.");
560             }
561           }
562         }
563       }
564     }
565 
566     if (debug_abbrev_file_size > 0 && debug_info_file_size > 0)
567       abilities |= CompileUnits | Functions | Blocks | GlobalVariables |
568                    LocalVariables | VariableTypes;
569 
570     if (debug_line_file_size > 0)
571       abilities |= LineTables;
572   }
573   return abilities;
574 }
575 
576 const DWARFDataExtractor &
577 SymbolFileDWARF::GetCachedSectionData(lldb::SectionType sect_type,
578                                       DWARFDataSegment &data_segment) {
579   llvm::call_once(data_segment.m_flag, [this, sect_type, &data_segment] {
580     this->LoadSectionData(sect_type, std::ref(data_segment.m_data));
581   });
582   return data_segment.m_data;
583 }
584 
585 void SymbolFileDWARF::LoadSectionData(lldb::SectionType sect_type,
586                                       DWARFDataExtractor &data) {
587   ModuleSP module_sp(m_objfile_sp->GetModule());
588   const SectionList *section_list = module_sp->GetSectionList();
589   if (!section_list)
590     return;
591 
592   SectionSP section_sp(section_list->FindSectionByType(sect_type, true));
593   if (!section_sp)
594     return;
595 
596   data.Clear();
597   m_objfile_sp->ReadSectionData(section_sp.get(), data);
598 }
599 
600 const DWARFDataExtractor &SymbolFileDWARF::get_debug_loc_data() {
601   return GetCachedSectionData(eSectionTypeDWARFDebugLoc, m_data_debug_loc);
602 }
603 
604 const DWARFDataExtractor &SymbolFileDWARF::get_debug_loclists_data() {
605   return GetCachedSectionData(eSectionTypeDWARFDebugLocLists,
606                               m_data_debug_loclists);
607 }
608 
609 DWARFDebugAbbrev *SymbolFileDWARF::DebugAbbrev() {
610   if (m_abbr)
611     return m_abbr.get();
612 
613   const DWARFDataExtractor &debug_abbrev_data = m_context.getOrLoadAbbrevData();
614   if (debug_abbrev_data.GetByteSize() == 0)
615     return nullptr;
616 
617   auto abbr = std::make_unique<DWARFDebugAbbrev>();
618   llvm::Error error = abbr->parse(debug_abbrev_data);
619   if (error) {
620     Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
621     LLDB_LOG_ERROR(log, std::move(error),
622                    "Unable to read .debug_abbrev section: {0}");
623     return nullptr;
624   }
625 
626   m_abbr = std::move(abbr);
627   return m_abbr.get();
628 }
629 
630 const DWARFDebugAbbrev *SymbolFileDWARF::DebugAbbrev() const {
631   return m_abbr.get();
632 }
633 
634 DWARFDebugInfo *SymbolFileDWARF::DebugInfo() {
635   if (m_info == nullptr) {
636     static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
637     Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
638                        static_cast<void *>(this));
639     if (m_context.getOrLoadDebugInfoData().GetByteSize() > 0)
640       m_info = std::make_unique<DWARFDebugInfo>(*this, m_context);
641   }
642   return m_info.get();
643 }
644 
645 const DWARFDebugInfo *SymbolFileDWARF::DebugInfo() const {
646   return m_info.get();
647 }
648 
649 DWARFUnit *
650 SymbolFileDWARF::GetDWARFCompileUnit(lldb_private::CompileUnit *comp_unit) {
651   if (!comp_unit)
652     return nullptr;
653 
654   DWARFDebugInfo *info = DebugInfo();
655   if (info) {
656     // The compile unit ID is the index of the DWARF unit.
657     DWARFUnit *dwarf_cu = info->GetUnitAtIndex(comp_unit->GetID());
658     if (dwarf_cu && dwarf_cu->GetUserData() == nullptr)
659       dwarf_cu->SetUserData(comp_unit);
660     return dwarf_cu;
661   }
662   return nullptr;
663 }
664 
665 DWARFDebugRanges *SymbolFileDWARF::GetDebugRanges() {
666   if (!m_ranges) {
667     static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
668     Timer scoped_timer(func_cat, "%s this = %p", LLVM_PRETTY_FUNCTION,
669                        static_cast<void *>(this));
670 
671     if (m_context.getOrLoadRangesData().GetByteSize() > 0)
672       m_ranges.reset(new DWARFDebugRanges());
673 
674     if (m_ranges)
675       m_ranges->Extract(m_context);
676   }
677   return m_ranges.get();
678 }
679 
680 lldb::CompUnitSP SymbolFileDWARF::ParseCompileUnit(DWARFCompileUnit &dwarf_cu) {
681   CompUnitSP cu_sp;
682   CompileUnit *comp_unit = (CompileUnit *)dwarf_cu.GetUserData();
683   if (comp_unit) {
684     // We already parsed this compile unit, had out a shared pointer to it
685     cu_sp = comp_unit->shared_from_this();
686   } else {
687     if (&dwarf_cu.GetSymbolFileDWARF() != this) {
688       return dwarf_cu.GetSymbolFileDWARF().ParseCompileUnit(dwarf_cu);
689     } else if (dwarf_cu.GetOffset() == 0 && GetDebugMapSymfile()) {
690       // Let the debug map create the compile unit
691       cu_sp = m_debug_map_symfile->GetCompileUnit(this);
692       dwarf_cu.SetUserData(cu_sp.get());
693     } else {
694       ModuleSP module_sp(m_objfile_sp->GetModule());
695       if (module_sp) {
696         const DWARFBaseDIE cu_die =
697             dwarf_cu.GetNonSkeletonUnit().GetUnitDIEOnly();
698         if (cu_die) {
699           FileSpec cu_file_spec(cu_die.GetName(), dwarf_cu.GetPathStyle());
700           if (cu_file_spec) {
701             // If we have a full path to the compile unit, we don't need to
702             // resolve the file.  This can be expensive e.g. when the source
703             // files are NFS mounted.
704             cu_file_spec.MakeAbsolute(dwarf_cu.GetCompilationDirectory());
705 
706             std::string remapped_file;
707             if (module_sp->RemapSourceFile(cu_file_spec.GetPath(),
708                                            remapped_file))
709               cu_file_spec.SetFile(remapped_file, FileSpec::Style::native);
710           }
711 
712           LanguageType cu_language = DWARFUnit::LanguageTypeFromDWARF(
713               cu_die.GetAttributeValueAsUnsigned(DW_AT_language, 0));
714 
715           bool is_optimized = dwarf_cu.GetNonSkeletonUnit().GetIsOptimized();
716           BuildCuTranslationTable();
717           cu_sp = std::make_shared<CompileUnit>(
718               module_sp, &dwarf_cu, cu_file_spec,
719               *GetDWARFUnitIndex(dwarf_cu.GetID()), cu_language,
720               is_optimized ? eLazyBoolYes : eLazyBoolNo);
721 
722           dwarf_cu.SetUserData(cu_sp.get());
723 
724           SetCompileUnitAtIndex(dwarf_cu.GetID(), cu_sp);
725         }
726       }
727     }
728   }
729   return cu_sp;
730 }
731 
732 void SymbolFileDWARF::BuildCuTranslationTable() {
733   if (!m_lldb_cu_to_dwarf_unit.empty())
734     return;
735 
736   DWARFDebugInfo *info = DebugInfo();
737   if (!info)
738     return;
739 
740   if (!info->ContainsTypeUnits()) {
741     // We can use a 1-to-1 mapping. No need to build a translation table.
742     return;
743   }
744   for (uint32_t i = 0, num = info->GetNumUnits(); i < num; ++i) {
745     if (auto *cu = llvm::dyn_cast<DWARFCompileUnit>(info->GetUnitAtIndex(i))) {
746       cu->SetID(m_lldb_cu_to_dwarf_unit.size());
747       m_lldb_cu_to_dwarf_unit.push_back(i);
748     }
749   }
750 }
751 
752 llvm::Optional<uint32_t> SymbolFileDWARF::GetDWARFUnitIndex(uint32_t cu_idx) {
753   BuildCuTranslationTable();
754   if (m_lldb_cu_to_dwarf_unit.empty())
755     return cu_idx;
756   if (cu_idx >= m_lldb_cu_to_dwarf_unit.size())
757     return llvm::None;
758   return m_lldb_cu_to_dwarf_unit[cu_idx];
759 }
760 
761 uint32_t SymbolFileDWARF::CalculateNumCompileUnits() {
762   DWARFDebugInfo *info = DebugInfo();
763   if (!info)
764     return 0;
765   BuildCuTranslationTable();
766   return m_lldb_cu_to_dwarf_unit.empty() ? info->GetNumUnits()
767                                          : m_lldb_cu_to_dwarf_unit.size();
768 }
769 
770 CompUnitSP SymbolFileDWARF::ParseCompileUnitAtIndex(uint32_t cu_idx) {
771   ASSERT_MODULE_LOCK(this);
772   DWARFDebugInfo *info = DebugInfo();
773   if (!info)
774     return {};
775 
776   if (llvm::Optional<uint32_t> dwarf_idx = GetDWARFUnitIndex(cu_idx)) {
777     if (auto *dwarf_cu = llvm::cast_or_null<DWARFCompileUnit>(
778             info->GetUnitAtIndex(*dwarf_idx)))
779       return ParseCompileUnit(*dwarf_cu);
780   }
781   return {};
782 }
783 
784 Function *SymbolFileDWARF::ParseFunction(CompileUnit &comp_unit,
785                                          const DWARFDIE &die) {
786   ASSERT_MODULE_LOCK(this);
787   if (!die.IsValid())
788     return nullptr;
789 
790   auto type_system_or_err =
791       GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
792   if (auto err = type_system_or_err.takeError()) {
793     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
794                    std::move(err), "Unable to parse function");
795     return nullptr;
796   }
797   DWARFASTParser *dwarf_ast = type_system_or_err->GetDWARFParser();
798   if (!dwarf_ast)
799     return nullptr;
800 
801   return dwarf_ast->ParseFunctionFromDWARF(comp_unit, die);
802 }
803 
804 bool SymbolFileDWARF::FixupAddress(Address &addr) {
805   SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
806   if (debug_map_symfile) {
807     return debug_map_symfile->LinkOSOAddress(addr);
808   }
809   // This is a normal DWARF file, no address fixups need to happen
810   return true;
811 }
812 lldb::LanguageType SymbolFileDWARF::ParseLanguage(CompileUnit &comp_unit) {
813   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
814   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
815   if (dwarf_cu)
816     return dwarf_cu->GetLanguageType();
817   else
818     return eLanguageTypeUnknown;
819 }
820 
821 size_t SymbolFileDWARF::ParseFunctions(CompileUnit &comp_unit) {
822   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
823   Timer scoped_timer(func_cat, "SymbolFileDWARF::ParseFunctions");
824   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
825   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
826   if (!dwarf_cu)
827     return 0;
828 
829   size_t functions_added = 0;
830   dwarf_cu = &dwarf_cu->GetNonSkeletonUnit();
831   for (DWARFDebugInfoEntry &entry : dwarf_cu->dies()) {
832     if (entry.Tag() != DW_TAG_subprogram)
833       continue;
834 
835     DWARFDIE die(dwarf_cu, &entry);
836     if (comp_unit.FindFunctionByUID(die.GetID()))
837       continue;
838     if (ParseFunction(comp_unit, die))
839       ++functions_added;
840   }
841   // FixupTypes();
842   return functions_added;
843 }
844 
845 bool SymbolFileDWARF::ForEachExternalModule(
846     CompileUnit &comp_unit,
847     llvm::DenseSet<lldb_private::SymbolFile *> &visited_symbol_files,
848     llvm::function_ref<bool(Module &)> lambda) {
849   // Only visit each symbol file once.
850   if (!visited_symbol_files.insert(this).second)
851     return false;
852 
853   UpdateExternalModuleListIfNeeded();
854   for (auto &p : m_external_type_modules) {
855     ModuleSP module = p.second;
856     if (!module)
857       continue;
858 
859     // Invoke the action and potentially early-exit.
860     if (lambda(*module))
861       return true;
862 
863     for (std::size_t i = 0; i < module->GetNumCompileUnits(); ++i) {
864       auto cu = module->GetCompileUnitAtIndex(i);
865       bool early_exit = cu->ForEachExternalModule(visited_symbol_files, lambda);
866       if (early_exit)
867         return true;
868     }
869   }
870   return false;
871 }
872 
873 bool SymbolFileDWARF::ParseSupportFiles(CompileUnit &comp_unit,
874                                         FileSpecList &support_files) {
875   if (!comp_unit.GetLineTable())
876     ParseLineTable(comp_unit);
877   return true;
878 }
879 
880 FileSpec SymbolFileDWARF::GetFile(DWARFUnit &unit, size_t file_idx) {
881   if (auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(&unit)) {
882     if (CompileUnit *lldb_cu = GetCompUnitForDWARFCompUnit(*dwarf_cu))
883       return lldb_cu->GetSupportFiles().GetFileSpecAtIndex(file_idx);
884     return FileSpec();
885   }
886 
887   auto &tu = llvm::cast<DWARFTypeUnit>(unit);
888   return GetTypeUnitSupportFiles(tu).GetFileSpecAtIndex(file_idx);
889 }
890 
891 const FileSpecList &
892 SymbolFileDWARF::GetTypeUnitSupportFiles(DWARFTypeUnit &tu) {
893   static FileSpecList empty_list;
894 
895   dw_offset_t offset = tu.GetLineTableOffset();
896   if (offset == DW_INVALID_OFFSET ||
897       offset == llvm::DenseMapInfo<dw_offset_t>::getEmptyKey() ||
898       offset == llvm::DenseMapInfo<dw_offset_t>::getTombstoneKey())
899     return empty_list;
900 
901   // Many type units can share a line table, so parse the support file list
902   // once, and cache it based on the offset field.
903   auto iter_bool = m_type_unit_support_files.try_emplace(offset);
904   FileSpecList &list = iter_bool.first->second;
905   if (iter_bool.second) {
906     uint64_t line_table_offset = offset;
907     llvm::DWARFDataExtractor data = m_context.getOrLoadLineData().GetAsLLVM();
908     llvm::DWARFContext &ctx = m_context.GetAsLLVM();
909     llvm::DWARFDebugLine::Prologue prologue;
910     llvm::Error error = prologue.parse(data, &line_table_offset, ctx);
911     if (error) {
912       Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
913       LLDB_LOG_ERROR(log, std::move(error),
914                      "SymbolFileDWARF::GetTypeUnitSupportFiles failed to parse "
915                      "the line table prologue");
916     } else {
917       list = ParseSupportFilesFromPrologue(GetObjectFile()->GetModule(),
918                                            prologue, tu.GetPathStyle());
919     }
920   }
921   return list;
922 }
923 
924 bool SymbolFileDWARF::ParseIsOptimized(CompileUnit &comp_unit) {
925   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
926   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
927   if (dwarf_cu)
928     return dwarf_cu->GetIsOptimized();
929   return false;
930 }
931 
932 bool SymbolFileDWARF::ParseImportedModules(
933     const lldb_private::SymbolContext &sc,
934     std::vector<SourceModule> &imported_modules) {
935   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
936   assert(sc.comp_unit);
937   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(sc.comp_unit);
938   if (!dwarf_cu)
939     return false;
940   if (!ClangModulesDeclVendor::LanguageSupportsClangModules(
941           sc.comp_unit->GetLanguage()))
942     return false;
943   UpdateExternalModuleListIfNeeded();
944 
945   const DWARFDIE die = dwarf_cu->DIE();
946   if (!die)
947     return false;
948 
949   for (DWARFDIE child_die = die.GetFirstChild(); child_die;
950        child_die = child_die.GetSibling()) {
951     if (child_die.Tag() != DW_TAG_imported_declaration)
952       continue;
953 
954     DWARFDIE module_die = child_die.GetReferencedDIE(DW_AT_import);
955     if (module_die.Tag() != DW_TAG_module)
956       continue;
957 
958     if (const char *name =
959             module_die.GetAttributeValueAsString(DW_AT_name, nullptr)) {
960       SourceModule module;
961       module.path.push_back(ConstString(name));
962 
963       DWARFDIE parent_die = module_die;
964       while ((parent_die = parent_die.GetParent())) {
965         if (parent_die.Tag() != DW_TAG_module)
966           break;
967         if (const char *name =
968                 parent_die.GetAttributeValueAsString(DW_AT_name, nullptr))
969           module.path.push_back(ConstString(name));
970       }
971       std::reverse(module.path.begin(), module.path.end());
972       if (const char *include_path = module_die.GetAttributeValueAsString(
973               DW_AT_LLVM_include_path, nullptr))
974         module.search_path = ConstString(include_path);
975       if (const char *sysroot = module_die.GetAttributeValueAsString(
976               DW_AT_LLVM_sysroot, nullptr))
977         module.sysroot = ConstString(sysroot);
978       imported_modules.push_back(module);
979     }
980   }
981   return true;
982 }
983 
984 bool SymbolFileDWARF::ParseLineTable(CompileUnit &comp_unit) {
985   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
986   if (comp_unit.GetLineTable() != nullptr)
987     return true;
988 
989   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
990   if (!dwarf_cu)
991     return false;
992 
993   const DWARFBaseDIE dwarf_cu_die = dwarf_cu->GetUnitDIEOnly();
994   if (!dwarf_cu_die)
995     return false;
996 
997   const dw_offset_t cu_line_offset = dwarf_cu_die.GetAttributeValueAsUnsigned(
998       DW_AT_stmt_list, DW_INVALID_OFFSET);
999   if (cu_line_offset == DW_INVALID_OFFSET)
1000     return false;
1001 
1002   llvm::DWARFDebugLine line;
1003   const llvm::DWARFDebugLine::LineTable *line_table = ParseLLVMLineTable(
1004       m_context, line, cu_line_offset, dwarf_cu->GetOffset());
1005 
1006   if (!line_table)
1007     return false;
1008 
1009   // FIXME: Rather than parsing the whole line table and then copying it over
1010   // into LLDB, we should explore using a callback to populate the line table
1011   // while we parse to reduce memory usage.
1012   std::unique_ptr<LineTable> line_table_up =
1013       std::make_unique<LineTable>(&comp_unit);
1014   LineSequence *sequence = line_table_up->CreateLineSequenceContainer();
1015   for (auto &row : line_table->Rows) {
1016     line_table_up->AppendLineEntryToSequence(
1017         sequence, row.Address.Address, row.Line, row.Column, row.File,
1018         row.IsStmt, row.BasicBlock, row.PrologueEnd, row.EpilogueBegin,
1019         row.EndSequence);
1020     if (row.EndSequence) {
1021       line_table_up->InsertSequence(sequence);
1022       sequence = line_table_up->CreateLineSequenceContainer();
1023     }
1024   }
1025 
1026   if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile()) {
1027     // We have an object file that has a line table with addresses that are not
1028     // linked. We need to link the line table and convert the addresses that
1029     // are relative to the .o file into addresses for the main executable.
1030     comp_unit.SetLineTable(
1031         debug_map_symfile->LinkOSOLineTable(this, line_table_up.get()));
1032   } else {
1033     comp_unit.SetLineTable(line_table_up.release());
1034   }
1035 
1036   comp_unit.SetSupportFiles(ParseSupportFilesFromPrologue(
1037       comp_unit.GetModule(), line_table->Prologue, dwarf_cu->GetPathStyle(),
1038       dwarf_cu->GetCompilationDirectory().GetCString()));
1039 
1040   return true;
1041 }
1042 
1043 lldb_private::DebugMacrosSP
1044 SymbolFileDWARF::ParseDebugMacros(lldb::offset_t *offset) {
1045   auto iter = m_debug_macros_map.find(*offset);
1046   if (iter != m_debug_macros_map.end())
1047     return iter->second;
1048 
1049   const DWARFDataExtractor &debug_macro_data = m_context.getOrLoadMacroData();
1050   if (debug_macro_data.GetByteSize() == 0)
1051     return DebugMacrosSP();
1052 
1053   lldb_private::DebugMacrosSP debug_macros_sp(new lldb_private::DebugMacros());
1054   m_debug_macros_map[*offset] = debug_macros_sp;
1055 
1056   const DWARFDebugMacroHeader &header =
1057       DWARFDebugMacroHeader::ParseHeader(debug_macro_data, offset);
1058   DWARFDebugMacroEntry::ReadMacroEntries(
1059       debug_macro_data, m_context.getOrLoadStrData(), header.OffsetIs64Bit(),
1060       offset, this, debug_macros_sp);
1061 
1062   return debug_macros_sp;
1063 }
1064 
1065 bool SymbolFileDWARF::ParseDebugMacros(CompileUnit &comp_unit) {
1066   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1067 
1068   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
1069   if (dwarf_cu == nullptr)
1070     return false;
1071 
1072   const DWARFBaseDIE dwarf_cu_die = dwarf_cu->GetUnitDIEOnly();
1073   if (!dwarf_cu_die)
1074     return false;
1075 
1076   lldb::offset_t sect_offset =
1077       dwarf_cu_die.GetAttributeValueAsUnsigned(DW_AT_macros, DW_INVALID_OFFSET);
1078   if (sect_offset == DW_INVALID_OFFSET)
1079     sect_offset = dwarf_cu_die.GetAttributeValueAsUnsigned(DW_AT_GNU_macros,
1080                                                            DW_INVALID_OFFSET);
1081   if (sect_offset == DW_INVALID_OFFSET)
1082     return false;
1083 
1084   comp_unit.SetDebugMacros(ParseDebugMacros(&sect_offset));
1085 
1086   return true;
1087 }
1088 
1089 size_t SymbolFileDWARF::ParseBlocksRecursive(
1090     lldb_private::CompileUnit &comp_unit, Block *parent_block,
1091     const DWARFDIE &orig_die, addr_t subprogram_low_pc, uint32_t depth) {
1092   size_t blocks_added = 0;
1093   DWARFDIE die = orig_die;
1094   while (die) {
1095     dw_tag_t tag = die.Tag();
1096 
1097     switch (tag) {
1098     case DW_TAG_inlined_subroutine:
1099     case DW_TAG_subprogram:
1100     case DW_TAG_lexical_block: {
1101       Block *block = nullptr;
1102       if (tag == DW_TAG_subprogram) {
1103         // Skip any DW_TAG_subprogram DIEs that are inside of a normal or
1104         // inlined functions. These will be parsed on their own as separate
1105         // entities.
1106 
1107         if (depth > 0)
1108           break;
1109 
1110         block = parent_block;
1111       } else {
1112         BlockSP block_sp(new Block(die.GetID()));
1113         parent_block->AddChild(block_sp);
1114         block = block_sp.get();
1115       }
1116       DWARFRangeList ranges;
1117       const char *name = nullptr;
1118       const char *mangled_name = nullptr;
1119 
1120       int decl_file = 0;
1121       int decl_line = 0;
1122       int decl_column = 0;
1123       int call_file = 0;
1124       int call_line = 0;
1125       int call_column = 0;
1126       if (die.GetDIENamesAndRanges(name, mangled_name, ranges, decl_file,
1127                                    decl_line, decl_column, call_file, call_line,
1128                                    call_column, nullptr)) {
1129         if (tag == DW_TAG_subprogram) {
1130           assert(subprogram_low_pc == LLDB_INVALID_ADDRESS);
1131           subprogram_low_pc = ranges.GetMinRangeBase(0);
1132         } else if (tag == DW_TAG_inlined_subroutine) {
1133           // We get called here for inlined subroutines in two ways. The first
1134           // time is when we are making the Function object for this inlined
1135           // concrete instance.  Since we're creating a top level block at
1136           // here, the subprogram_low_pc will be LLDB_INVALID_ADDRESS.  So we
1137           // need to adjust the containing address. The second time is when we
1138           // are parsing the blocks inside the function that contains the
1139           // inlined concrete instance.  Since these will be blocks inside the
1140           // containing "real" function the offset will be for that function.
1141           if (subprogram_low_pc == LLDB_INVALID_ADDRESS) {
1142             subprogram_low_pc = ranges.GetMinRangeBase(0);
1143           }
1144         }
1145 
1146         const size_t num_ranges = ranges.GetSize();
1147         for (size_t i = 0; i < num_ranges; ++i) {
1148           const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
1149           const addr_t range_base = range.GetRangeBase();
1150           if (range_base >= subprogram_low_pc)
1151             block->AddRange(Block::Range(range_base - subprogram_low_pc,
1152                                          range.GetByteSize()));
1153           else {
1154             GetObjectFile()->GetModule()->ReportError(
1155                 "0x%8.8" PRIx64 ": adding range [0x%" PRIx64 "-0x%" PRIx64
1156                 ") which has a base that is less than the function's low PC "
1157                 "0x%" PRIx64 ". Please file a bug and attach the file at the "
1158                 "start of this error message",
1159                 block->GetID(), range_base, range.GetRangeEnd(),
1160                 subprogram_low_pc);
1161           }
1162         }
1163         block->FinalizeRanges();
1164 
1165         if (tag != DW_TAG_subprogram &&
1166             (name != nullptr || mangled_name != nullptr)) {
1167           std::unique_ptr<Declaration> decl_up;
1168           if (decl_file != 0 || decl_line != 0 || decl_column != 0)
1169             decl_up.reset(new Declaration(
1170                 comp_unit.GetSupportFiles().GetFileSpecAtIndex(decl_file),
1171                 decl_line, decl_column));
1172 
1173           std::unique_ptr<Declaration> call_up;
1174           if (call_file != 0 || call_line != 0 || call_column != 0)
1175             call_up.reset(new Declaration(
1176                 comp_unit.GetSupportFiles().GetFileSpecAtIndex(call_file),
1177                 call_line, call_column));
1178 
1179           block->SetInlinedFunctionInfo(name, mangled_name, decl_up.get(),
1180                                         call_up.get());
1181         }
1182 
1183         ++blocks_added;
1184 
1185         if (die.HasChildren()) {
1186           blocks_added +=
1187               ParseBlocksRecursive(comp_unit, block, die.GetFirstChild(),
1188                                    subprogram_low_pc, depth + 1);
1189         }
1190       }
1191     } break;
1192     default:
1193       break;
1194     }
1195 
1196     // Only parse siblings of the block if we are not at depth zero. A depth of
1197     // zero indicates we are currently parsing the top level DW_TAG_subprogram
1198     // DIE
1199 
1200     if (depth == 0)
1201       die.Clear();
1202     else
1203       die = die.GetSibling();
1204   }
1205   return blocks_added;
1206 }
1207 
1208 bool SymbolFileDWARF::ClassOrStructIsVirtual(const DWARFDIE &parent_die) {
1209   if (parent_die) {
1210     for (DWARFDIE die = parent_die.GetFirstChild(); die;
1211          die = die.GetSibling()) {
1212       dw_tag_t tag = die.Tag();
1213       bool check_virtuality = false;
1214       switch (tag) {
1215       case DW_TAG_inheritance:
1216       case DW_TAG_subprogram:
1217         check_virtuality = true;
1218         break;
1219       default:
1220         break;
1221       }
1222       if (check_virtuality) {
1223         if (die.GetAttributeValueAsUnsigned(DW_AT_virtuality, 0) != 0)
1224           return true;
1225       }
1226     }
1227   }
1228   return false;
1229 }
1230 
1231 void SymbolFileDWARF::ParseDeclsForContext(CompilerDeclContext decl_ctx) {
1232   auto *type_system = decl_ctx.GetTypeSystem();
1233   if (type_system != nullptr)
1234     type_system->GetDWARFParser()->EnsureAllDIEsInDeclContextHaveBeenParsed(
1235         decl_ctx);
1236 }
1237 
1238 user_id_t SymbolFileDWARF::GetUID(DIERef ref) {
1239   if (GetDebugMapSymfile())
1240     return GetID() | ref.die_offset();
1241 
1242   return user_id_t(GetDwoNum().getValueOr(0x7fffffff)) << 32 |
1243          ref.die_offset() |
1244          (lldb::user_id_t(ref.section() == DIERef::Section::DebugTypes) << 63);
1245 }
1246 
1247 llvm::Optional<SymbolFileDWARF::DecodedUID>
1248 SymbolFileDWARF::DecodeUID(lldb::user_id_t uid) {
1249   // This method can be called without going through the symbol vendor so we
1250   // need to lock the module.
1251   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1252   // Anytime we get a "lldb::user_id_t" from an lldb_private::SymbolFile API we
1253   // must make sure we use the correct DWARF file when resolving things. On
1254   // MacOSX, when using SymbolFileDWARFDebugMap, we will use multiple
1255   // SymbolFileDWARF classes, one for each .o file. We can often end up with
1256   // references to other DWARF objects and we must be ready to receive a
1257   // "lldb::user_id_t" that specifies a DIE from another SymbolFileDWARF
1258   // instance.
1259   if (SymbolFileDWARFDebugMap *debug_map = GetDebugMapSymfile()) {
1260     SymbolFileDWARF *dwarf = debug_map->GetSymbolFileByOSOIndex(
1261         debug_map->GetOSOIndexFromUserID(uid));
1262     return DecodedUID{
1263         *dwarf, {llvm::None, DIERef::Section::DebugInfo, dw_offset_t(uid)}};
1264   }
1265   dw_offset_t die_offset = uid;
1266   if (die_offset == DW_INVALID_OFFSET)
1267     return llvm::None;
1268 
1269   DIERef::Section section =
1270       uid >> 63 ? DIERef::Section::DebugTypes : DIERef::Section::DebugInfo;
1271 
1272   llvm::Optional<uint32_t> dwo_num = uid >> 32 & 0x7fffffff;
1273   if (*dwo_num == 0x7fffffff)
1274     dwo_num = llvm::None;
1275 
1276   return DecodedUID{*this, {dwo_num, section, die_offset}};
1277 }
1278 
1279 DWARFDIE
1280 SymbolFileDWARF::GetDIE(lldb::user_id_t uid) {
1281   // This method can be called without going through the symbol vendor so we
1282   // need to lock the module.
1283   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1284 
1285   llvm::Optional<DecodedUID> decoded = DecodeUID(uid);
1286 
1287   if (decoded)
1288     return decoded->dwarf.GetDIE(decoded->ref);
1289 
1290   return DWARFDIE();
1291 }
1292 
1293 CompilerDecl SymbolFileDWARF::GetDeclForUID(lldb::user_id_t type_uid) {
1294   // This method can be called without going through the symbol vendor so we
1295   // need to lock the module.
1296   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1297   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
1298   // SymbolFileDWARF::GetDIE(). See comments inside the
1299   // SymbolFileDWARF::GetDIE() for details.
1300   if (DWARFDIE die = GetDIE(type_uid))
1301     return die.GetDecl();
1302   return CompilerDecl();
1303 }
1304 
1305 CompilerDeclContext
1306 SymbolFileDWARF::GetDeclContextForUID(lldb::user_id_t type_uid) {
1307   // This method can be called without going through the symbol vendor so we
1308   // need to lock the module.
1309   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1310   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
1311   // SymbolFileDWARF::GetDIE(). See comments inside the
1312   // SymbolFileDWARF::GetDIE() for details.
1313   if (DWARFDIE die = GetDIE(type_uid))
1314     return die.GetDeclContext();
1315   return CompilerDeclContext();
1316 }
1317 
1318 CompilerDeclContext
1319 SymbolFileDWARF::GetDeclContextContainingUID(lldb::user_id_t type_uid) {
1320   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1321   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
1322   // SymbolFileDWARF::GetDIE(). See comments inside the
1323   // SymbolFileDWARF::GetDIE() for details.
1324   if (DWARFDIE die = GetDIE(type_uid))
1325     return die.GetContainingDeclContext();
1326   return CompilerDeclContext();
1327 }
1328 
1329 Type *SymbolFileDWARF::ResolveTypeUID(lldb::user_id_t type_uid) {
1330   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1331   // Anytime we have a lldb::user_id_t, we must get the DIE by calling
1332   // SymbolFileDWARF::GetDIE(). See comments inside the
1333   // SymbolFileDWARF::GetDIE() for details.
1334   if (DWARFDIE type_die = GetDIE(type_uid))
1335     return type_die.ResolveType();
1336   else
1337     return nullptr;
1338 }
1339 
1340 llvm::Optional<SymbolFile::ArrayInfo>
1341 SymbolFileDWARF::GetDynamicArrayInfoForUID(
1342     lldb::user_id_t type_uid, const lldb_private::ExecutionContext *exe_ctx) {
1343   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1344   if (DWARFDIE type_die = GetDIE(type_uid))
1345     return DWARFASTParser::ParseChildArrayInfo(type_die, exe_ctx);
1346   else
1347     return llvm::None;
1348 }
1349 
1350 Type *SymbolFileDWARF::ResolveTypeUID(const DIERef &die_ref) {
1351   return ResolveType(GetDIE(die_ref), true);
1352 }
1353 
1354 Type *SymbolFileDWARF::ResolveTypeUID(const DWARFDIE &die,
1355                                       bool assert_not_being_parsed) {
1356   if (die) {
1357     Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO));
1358     if (log)
1359       GetObjectFile()->GetModule()->LogMessage(
1360           log, "SymbolFileDWARF::ResolveTypeUID (die = 0x%8.8x) %s '%s'",
1361           die.GetOffset(), die.GetTagAsCString(), die.GetName());
1362 
1363     // We might be coming in in the middle of a type tree (a class within a
1364     // class, an enum within a class), so parse any needed parent DIEs before
1365     // we get to this one...
1366     DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(die);
1367     if (decl_ctx_die) {
1368       if (log) {
1369         switch (decl_ctx_die.Tag()) {
1370         case DW_TAG_structure_type:
1371         case DW_TAG_union_type:
1372         case DW_TAG_class_type: {
1373           // Get the type, which could be a forward declaration
1374           if (log)
1375             GetObjectFile()->GetModule()->LogMessage(
1376                 log,
1377                 "SymbolFileDWARF::ResolveTypeUID (die = 0x%8.8x) %s '%s' "
1378                 "resolve parent forward type for 0x%8.8x",
1379                 die.GetOffset(), die.GetTagAsCString(), die.GetName(),
1380                 decl_ctx_die.GetOffset());
1381         } break;
1382 
1383         default:
1384           break;
1385         }
1386       }
1387     }
1388     return ResolveType(die);
1389   }
1390   return nullptr;
1391 }
1392 
1393 // This function is used when SymbolFileDWARFDebugMap owns a bunch of
1394 // SymbolFileDWARF objects to detect if this DWARF file is the one that can
1395 // resolve a compiler_type.
1396 bool SymbolFileDWARF::HasForwardDeclForClangType(
1397     const CompilerType &compiler_type) {
1398   CompilerType compiler_type_no_qualifiers =
1399       ClangUtil::RemoveFastQualifiers(compiler_type);
1400   if (GetForwardDeclClangTypeToDie().count(
1401           compiler_type_no_qualifiers.GetOpaqueQualType())) {
1402     return true;
1403   }
1404   TypeSystem *type_system = compiler_type.GetTypeSystem();
1405 
1406   ClangASTContext *clang_type_system =
1407       llvm::dyn_cast_or_null<ClangASTContext>(type_system);
1408   if (!clang_type_system)
1409     return false;
1410   DWARFASTParserClang *ast_parser =
1411       static_cast<DWARFASTParserClang *>(clang_type_system->GetDWARFParser());
1412   return ast_parser->GetClangASTImporter().CanImport(compiler_type);
1413 }
1414 
1415 bool SymbolFileDWARF::CompleteType(CompilerType &compiler_type) {
1416   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1417 
1418   ClangASTContext *clang_type_system =
1419       llvm::dyn_cast_or_null<ClangASTContext>(compiler_type.GetTypeSystem());
1420   if (clang_type_system) {
1421     DWARFASTParserClang *ast_parser =
1422         static_cast<DWARFASTParserClang *>(clang_type_system->GetDWARFParser());
1423     if (ast_parser &&
1424         ast_parser->GetClangASTImporter().CanImport(compiler_type))
1425       return ast_parser->GetClangASTImporter().CompleteType(compiler_type);
1426   }
1427 
1428   // We have a struct/union/class/enum that needs to be fully resolved.
1429   CompilerType compiler_type_no_qualifiers =
1430       ClangUtil::RemoveFastQualifiers(compiler_type);
1431   auto die_it = GetForwardDeclClangTypeToDie().find(
1432       compiler_type_no_qualifiers.GetOpaqueQualType());
1433   if (die_it == GetForwardDeclClangTypeToDie().end()) {
1434     // We have already resolved this type...
1435     return true;
1436   }
1437 
1438   DWARFDIE dwarf_die = GetDIE(die_it->getSecond());
1439   if (dwarf_die) {
1440     // Once we start resolving this type, remove it from the forward
1441     // declaration map in case anyone child members or other types require this
1442     // type to get resolved. The type will get resolved when all of the calls
1443     // to SymbolFileDWARF::ResolveClangOpaqueTypeDefinition are done.
1444     GetForwardDeclClangTypeToDie().erase(die_it);
1445 
1446     Type *type = GetDIEToType().lookup(dwarf_die.GetDIE());
1447 
1448     Log *log(LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO |
1449                                           DWARF_LOG_TYPE_COMPLETION));
1450     if (log)
1451       GetObjectFile()->GetModule()->LogMessageVerboseBacktrace(
1452           log, "0x%8.8" PRIx64 ": %s '%s' resolving forward declaration...",
1453           dwarf_die.GetID(), dwarf_die.GetTagAsCString(),
1454           type->GetName().AsCString());
1455     assert(compiler_type);
1456     DWARFASTParser *dwarf_ast = dwarf_die.GetDWARFParser();
1457     if (dwarf_ast)
1458       return dwarf_ast->CompleteTypeFromDWARF(dwarf_die, type, compiler_type);
1459   }
1460   return false;
1461 }
1462 
1463 Type *SymbolFileDWARF::ResolveType(const DWARFDIE &die,
1464                                    bool assert_not_being_parsed,
1465                                    bool resolve_function_context) {
1466   if (die) {
1467     Type *type = GetTypeForDIE(die, resolve_function_context).get();
1468 
1469     if (assert_not_being_parsed) {
1470       if (type != DIE_IS_BEING_PARSED)
1471         return type;
1472 
1473       GetObjectFile()->GetModule()->ReportError(
1474           "Parsing a die that is being parsed die: 0x%8.8x: %s %s",
1475           die.GetOffset(), die.GetTagAsCString(), die.GetName());
1476 
1477     } else
1478       return type;
1479   }
1480   return nullptr;
1481 }
1482 
1483 CompileUnit *
1484 SymbolFileDWARF::GetCompUnitForDWARFCompUnit(DWARFCompileUnit &dwarf_cu) {
1485   // Check if the symbol vendor already knows about this compile unit?
1486   if (dwarf_cu.GetUserData() == nullptr) {
1487     // The symbol vendor doesn't know about this compile unit, we need to parse
1488     // and add it to the symbol vendor object.
1489     return ParseCompileUnit(dwarf_cu).get();
1490   }
1491   return (CompileUnit *)dwarf_cu.GetUserData();
1492 }
1493 
1494 size_t SymbolFileDWARF::GetObjCMethodDIEOffsets(ConstString class_name,
1495                                                 DIEArray &method_die_offsets) {
1496   method_die_offsets.clear();
1497   m_index->GetObjCMethods(class_name, method_die_offsets);
1498   return method_die_offsets.size();
1499 }
1500 
1501 bool SymbolFileDWARF::GetFunction(const DWARFDIE &die, SymbolContext &sc) {
1502   sc.Clear(false);
1503 
1504   if (die && llvm::isa<DWARFCompileUnit>(die.GetCU())) {
1505     // Check if the symbol vendor already knows about this compile unit?
1506     sc.comp_unit =
1507         GetCompUnitForDWARFCompUnit(llvm::cast<DWARFCompileUnit>(*die.GetCU()));
1508 
1509     sc.function = sc.comp_unit->FindFunctionByUID(die.GetID()).get();
1510     if (sc.function == nullptr)
1511       sc.function = ParseFunction(*sc.comp_unit, die);
1512 
1513     if (sc.function) {
1514       sc.module_sp = sc.function->CalculateSymbolContextModule();
1515       return true;
1516     }
1517   }
1518 
1519   return false;
1520 }
1521 
1522 lldb::ModuleSP SymbolFileDWARF::GetExternalModule(ConstString name) {
1523   UpdateExternalModuleListIfNeeded();
1524   const auto &pos = m_external_type_modules.find(name);
1525   if (pos != m_external_type_modules.end())
1526     return pos->second;
1527   else
1528     return lldb::ModuleSP();
1529 }
1530 
1531 DWARFDIE
1532 SymbolFileDWARF::GetDIE(const DIERef &die_ref) {
1533   if (die_ref.dwo_num()) {
1534     return DebugInfo()
1535         ->GetUnitAtIndex(*die_ref.dwo_num())
1536         ->GetDwoSymbolFile()
1537         ->GetDIE(die_ref);
1538   }
1539 
1540   DWARFDebugInfo *debug_info = DebugInfo();
1541   if (debug_info)
1542     return debug_info->GetDIE(die_ref);
1543   else
1544     return DWARFDIE();
1545 }
1546 
1547 /// Return the DW_AT_(GNU_)dwo_name.
1548 static const char *GetDWOName(DWARFCompileUnit &dwarf_cu,
1549                               const DWARFDebugInfoEntry &cu_die) {
1550   const char *dwo_name =
1551       cu_die.GetAttributeValueAsString(&dwarf_cu, DW_AT_GNU_dwo_name, nullptr);
1552   if (!dwo_name)
1553     dwo_name =
1554         cu_die.GetAttributeValueAsString(&dwarf_cu, DW_AT_dwo_name, nullptr);
1555   return dwo_name;
1556 }
1557 
1558 /// Return the DW_AT_(GNU_)dwo_id.
1559 /// FIXME: Technically 0 is a valid hash.
1560 static uint64_t GetDWOId(DWARFCompileUnit &dwarf_cu,
1561                          const DWARFDebugInfoEntry &cu_die) {
1562   uint64_t dwo_id =
1563       cu_die.GetAttributeValueAsUnsigned(&dwarf_cu, DW_AT_GNU_dwo_id, 0);
1564   if (!dwo_id)
1565     dwo_id = cu_die.GetAttributeValueAsUnsigned(&dwarf_cu, DW_AT_dwo_id, 0);
1566   return dwo_id;
1567 }
1568 
1569 llvm::Optional<uint64_t> SymbolFileDWARF::GetDWOId() {
1570   if (GetNumCompileUnits() == 1) {
1571     if (auto comp_unit = GetCompileUnitAtIndex(0))
1572       if (DWARFCompileUnit *cu = llvm::dyn_cast_or_null<DWARFCompileUnit>(
1573               GetDWARFCompileUnit(comp_unit.get())))
1574         if (DWARFDebugInfoEntry *cu_die = cu->DIE().GetDIE())
1575           if (uint64_t dwo_id = ::GetDWOId(*cu, *cu_die))
1576             return dwo_id;
1577   }
1578   return {};
1579 }
1580 
1581 std::unique_ptr<SymbolFileDWARFDwo>
1582 SymbolFileDWARF::GetDwoSymbolFileForCompileUnit(
1583     DWARFUnit &unit, const DWARFDebugInfoEntry &cu_die) {
1584   // If this is a Darwin-style debug map (non-.dSYM) symbol file,
1585   // never attempt to load ELF-style DWO files since the -gmodules
1586   // support uses the same DWO machanism to specify full debug info
1587   // files for modules. This is handled in
1588   // UpdateExternalModuleListIfNeeded().
1589   if (GetDebugMapSymfile())
1590     return nullptr;
1591 
1592   DWARFCompileUnit *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(&unit);
1593   // Only compile units can be split into two parts.
1594   if (!dwarf_cu)
1595     return nullptr;
1596 
1597   const char *dwo_name = GetDWOName(*dwarf_cu, cu_die);
1598   if (!dwo_name)
1599     return nullptr;
1600 
1601   SymbolFileDWARFDwp *dwp_symfile = GetDwpSymbolFile();
1602   if (dwp_symfile) {
1603     uint64_t dwo_id = ::GetDWOId(*dwarf_cu, cu_die);
1604     std::unique_ptr<SymbolFileDWARFDwo> dwo_symfile =
1605         dwp_symfile->GetSymbolFileForDwoId(*dwarf_cu, dwo_id);
1606     if (dwo_symfile)
1607       return dwo_symfile;
1608   }
1609 
1610   FileSpec dwo_file(dwo_name);
1611   FileSystem::Instance().Resolve(dwo_file);
1612   if (dwo_file.IsRelative()) {
1613     const char *comp_dir =
1614         cu_die.GetAttributeValueAsString(dwarf_cu, DW_AT_comp_dir, nullptr);
1615     if (!comp_dir)
1616       return nullptr;
1617 
1618     dwo_file.SetFile(comp_dir, FileSpec::Style::native);
1619     FileSystem::Instance().Resolve(dwo_file);
1620     dwo_file.AppendPathComponent(dwo_name);
1621   }
1622 
1623   if (!FileSystem::Instance().Exists(dwo_file))
1624     return nullptr;
1625 
1626   const lldb::offset_t file_offset = 0;
1627   DataBufferSP dwo_file_data_sp;
1628   lldb::offset_t dwo_file_data_offset = 0;
1629   ObjectFileSP dwo_obj_file = ObjectFile::FindPlugin(
1630       GetObjectFile()->GetModule(), &dwo_file, file_offset,
1631       FileSystem::Instance().GetByteSize(dwo_file), dwo_file_data_sp,
1632       dwo_file_data_offset);
1633   if (dwo_obj_file == nullptr)
1634     return nullptr;
1635 
1636   return std::make_unique<SymbolFileDWARFDwo>(dwo_obj_file, *dwarf_cu);
1637 }
1638 
1639 void SymbolFileDWARF::UpdateExternalModuleListIfNeeded() {
1640   if (m_fetched_external_modules)
1641     return;
1642   m_fetched_external_modules = true;
1643   DWARFDebugInfo *debug_info = DebugInfo();
1644 
1645   // Follow DWO skeleton unit breadcrumbs.
1646   const uint32_t num_compile_units = GetNumCompileUnits();
1647   for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
1648     auto *dwarf_cu =
1649         llvm::dyn_cast<DWARFCompileUnit>(debug_info->GetUnitAtIndex(cu_idx));
1650     if (!dwarf_cu)
1651       continue;
1652 
1653     const DWARFBaseDIE die = dwarf_cu->GetUnitDIEOnly();
1654     if (!die || die.HasChildren() || !die.GetDIE())
1655       continue;
1656 
1657     const char *name = die.GetAttributeValueAsString(DW_AT_name, nullptr);
1658     if (!name)
1659       continue;
1660 
1661     ConstString const_name(name);
1662     ModuleSP &module_sp = m_external_type_modules[const_name];
1663     if (module_sp)
1664       continue;
1665 
1666     const char *dwo_path = GetDWOName(*dwarf_cu, *die.GetDIE());
1667     if (!dwo_path)
1668       continue;
1669 
1670     ModuleSpec dwo_module_spec;
1671     dwo_module_spec.GetFileSpec().SetFile(dwo_path, FileSpec::Style::native);
1672     if (dwo_module_spec.GetFileSpec().IsRelative()) {
1673       const char *comp_dir =
1674           die.GetAttributeValueAsString(DW_AT_comp_dir, nullptr);
1675       if (comp_dir) {
1676         dwo_module_spec.GetFileSpec().SetFile(comp_dir,
1677                                               FileSpec::Style::native);
1678         FileSystem::Instance().Resolve(dwo_module_spec.GetFileSpec());
1679         dwo_module_spec.GetFileSpec().AppendPathComponent(dwo_path);
1680       }
1681     }
1682     dwo_module_spec.GetArchitecture() =
1683         m_objfile_sp->GetModule()->GetArchitecture();
1684 
1685     // When LLDB loads "external" modules it looks at the presence of
1686     // DW_AT_dwo_name. However, when the already created module
1687     // (corresponding to .dwo itself) is being processed, it will see
1688     // the presence of DW_AT_dwo_name (which contains the name of dwo
1689     // file) and will try to call ModuleList::GetSharedModule
1690     // again. In some cases (i.e., for empty files) Clang 4.0
1691     // generates a *.dwo file which has DW_AT_dwo_name, but no
1692     // DW_AT_comp_dir. In this case the method
1693     // ModuleList::GetSharedModule will fail and the warning will be
1694     // printed. However, as one can notice in this case we don't
1695     // actually need to try to load the already loaded module
1696     // (corresponding to .dwo) so we simply skip it.
1697     if (m_objfile_sp->GetFileSpec().GetFileNameExtension() == ".dwo" &&
1698         llvm::StringRef(m_objfile_sp->GetFileSpec().GetPath())
1699             .endswith(dwo_module_spec.GetFileSpec().GetPath())) {
1700       continue;
1701     }
1702 
1703     Status error = ModuleList::GetSharedModule(dwo_module_spec, module_sp,
1704                                                nullptr, nullptr, nullptr);
1705     if (!module_sp) {
1706       GetObjectFile()->GetModule()->ReportWarning(
1707           "0x%8.8x: unable to locate module needed for external types: "
1708           "%s\nerror: %s\nDebugging will be degraded due to missing "
1709           "types. Rebuilding the project will regenerate the needed "
1710           "module files.",
1711           die.GetOffset(), dwo_module_spec.GetFileSpec().GetPath().c_str(),
1712           error.AsCString("unknown error"));
1713       continue;
1714     }
1715 
1716     // Verify the DWO hash.
1717     // FIXME: Technically "0" is a valid hash.
1718     uint64_t dwo_id = ::GetDWOId(*dwarf_cu, *die.GetDIE());
1719     if (!dwo_id)
1720       continue;
1721 
1722     auto *dwo_symfile =
1723         llvm::dyn_cast_or_null<SymbolFileDWARF>(module_sp->GetSymbolFile());
1724     if (!dwo_symfile)
1725       continue;
1726     llvm::Optional<uint64_t> dwo_dwo_id = dwo_symfile->GetDWOId();
1727     if (!dwo_dwo_id)
1728       continue;
1729 
1730     if (dwo_id != dwo_dwo_id) {
1731       GetObjectFile()->GetModule()->ReportWarning(
1732           "0x%8.8x: Module %s is out-of-date (hash mismatch). Type information "
1733           "from this module may be incomplete or inconsistent with the rest of "
1734           "the program. Rebuilding the project will regenerate the needed "
1735           "module files.",
1736           die.GetOffset(), dwo_module_spec.GetFileSpec().GetPath().c_str());
1737     }
1738   }
1739 }
1740 
1741 SymbolFileDWARF::GlobalVariableMap &SymbolFileDWARF::GetGlobalAranges() {
1742   if (!m_global_aranges_up) {
1743     m_global_aranges_up.reset(new GlobalVariableMap());
1744 
1745     ModuleSP module_sp = GetObjectFile()->GetModule();
1746     if (module_sp) {
1747       const size_t num_cus = module_sp->GetNumCompileUnits();
1748       for (size_t i = 0; i < num_cus; ++i) {
1749         CompUnitSP cu_sp = module_sp->GetCompileUnitAtIndex(i);
1750         if (cu_sp) {
1751           VariableListSP globals_sp = cu_sp->GetVariableList(true);
1752           if (globals_sp) {
1753             const size_t num_globals = globals_sp->GetSize();
1754             for (size_t g = 0; g < num_globals; ++g) {
1755               VariableSP var_sp = globals_sp->GetVariableAtIndex(g);
1756               if (var_sp && !var_sp->GetLocationIsConstantValueData()) {
1757                 const DWARFExpression &location = var_sp->LocationExpression();
1758                 Value location_result;
1759                 Status error;
1760                 if (location.Evaluate(nullptr, LLDB_INVALID_ADDRESS, nullptr,
1761                                       nullptr, location_result, &error)) {
1762                   if (location_result.GetValueType() ==
1763                       Value::eValueTypeFileAddress) {
1764                     lldb::addr_t file_addr =
1765                         location_result.GetScalar().ULongLong();
1766                     lldb::addr_t byte_size = 1;
1767                     if (var_sp->GetType())
1768                       byte_size =
1769                           var_sp->GetType()->GetByteSize().getValueOr(0);
1770                     m_global_aranges_up->Append(GlobalVariableMap::Entry(
1771                         file_addr, byte_size, var_sp.get()));
1772                   }
1773                 }
1774               }
1775             }
1776           }
1777         }
1778       }
1779     }
1780     m_global_aranges_up->Sort();
1781   }
1782   return *m_global_aranges_up;
1783 }
1784 
1785 uint32_t SymbolFileDWARF::ResolveSymbolContext(const Address &so_addr,
1786                                                SymbolContextItem resolve_scope,
1787                                                SymbolContext &sc) {
1788   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1789   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
1790   Timer scoped_timer(func_cat,
1791                      "SymbolFileDWARF::"
1792                      "ResolveSymbolContext (so_addr = { "
1793                      "section = %p, offset = 0x%" PRIx64
1794                      " }, resolve_scope = 0x%8.8x)",
1795                      static_cast<void *>(so_addr.GetSection().get()),
1796                      so_addr.GetOffset(), resolve_scope);
1797   uint32_t resolved = 0;
1798   if (resolve_scope &
1799       (eSymbolContextCompUnit | eSymbolContextFunction | eSymbolContextBlock |
1800        eSymbolContextLineEntry | eSymbolContextVariable)) {
1801     lldb::addr_t file_vm_addr = so_addr.GetFileAddress();
1802 
1803     DWARFDebugInfo *debug_info = DebugInfo();
1804     if (debug_info) {
1805       llvm::Expected<DWARFDebugAranges &> aranges =
1806           debug_info->GetCompileUnitAranges();
1807       if (!aranges) {
1808         Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
1809         LLDB_LOG_ERROR(log, aranges.takeError(),
1810                        "SymbolFileDWARF::ResolveSymbolContext failed to get cu "
1811                        "aranges.  {0}");
1812         return 0;
1813       }
1814 
1815       const dw_offset_t cu_offset = aranges->FindAddress(file_vm_addr);
1816       if (cu_offset == DW_INVALID_OFFSET) {
1817         // Global variables are not in the compile unit address ranges. The
1818         // only way to currently find global variables is to iterate over the
1819         // .debug_pubnames or the __apple_names table and find all items in
1820         // there that point to DW_TAG_variable DIEs and then find the address
1821         // that matches.
1822         if (resolve_scope & eSymbolContextVariable) {
1823           GlobalVariableMap &map = GetGlobalAranges();
1824           const GlobalVariableMap::Entry *entry =
1825               map.FindEntryThatContains(file_vm_addr);
1826           if (entry && entry->data) {
1827             Variable *variable = entry->data;
1828             SymbolContextScope *scc = variable->GetSymbolContextScope();
1829             if (scc) {
1830               scc->CalculateSymbolContext(&sc);
1831               sc.variable = variable;
1832             }
1833             return sc.GetResolvedMask();
1834           }
1835         }
1836       } else {
1837         uint32_t cu_idx = DW_INVALID_INDEX;
1838         if (auto *dwarf_cu = llvm::dyn_cast_or_null<DWARFCompileUnit>(
1839                 debug_info->GetUnitAtOffset(DIERef::Section::DebugInfo,
1840                                             cu_offset, &cu_idx))) {
1841           sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
1842           if (sc.comp_unit) {
1843             resolved |= eSymbolContextCompUnit;
1844 
1845             bool force_check_line_table = false;
1846             if (resolve_scope &
1847                 (eSymbolContextFunction | eSymbolContextBlock)) {
1848               DWARFDIE function_die = dwarf_cu->LookupAddress(file_vm_addr);
1849               DWARFDIE block_die;
1850               if (function_die) {
1851                 sc.function =
1852                     sc.comp_unit->FindFunctionByUID(function_die.GetID()).get();
1853                 if (sc.function == nullptr)
1854                   sc.function = ParseFunction(*sc.comp_unit, function_die);
1855 
1856                 if (sc.function && (resolve_scope & eSymbolContextBlock))
1857                   block_die = function_die.LookupDeepestBlock(file_vm_addr);
1858               } else {
1859                 // We might have had a compile unit that had discontiguous
1860                 // address ranges where the gaps are symbols that don't have
1861                 // any debug info. Discontiguous compile unit address ranges
1862                 // should only happen when there aren't other functions from
1863                 // other compile units in these gaps. This helps keep the size
1864                 // of the aranges down.
1865                 force_check_line_table = true;
1866               }
1867 
1868               if (sc.function != nullptr) {
1869                 resolved |= eSymbolContextFunction;
1870 
1871                 if (resolve_scope & eSymbolContextBlock) {
1872                   Block &block = sc.function->GetBlock(true);
1873 
1874                   if (block_die)
1875                     sc.block = block.FindBlockByID(block_die.GetID());
1876                   else
1877                     sc.block = block.FindBlockByID(function_die.GetID());
1878                   if (sc.block)
1879                     resolved |= eSymbolContextBlock;
1880                 }
1881               }
1882             }
1883 
1884             if ((resolve_scope & eSymbolContextLineEntry) ||
1885                 force_check_line_table) {
1886               LineTable *line_table = sc.comp_unit->GetLineTable();
1887               if (line_table != nullptr) {
1888                 // And address that makes it into this function should be in
1889                 // terms of this debug file if there is no debug map, or it
1890                 // will be an address in the .o file which needs to be fixed up
1891                 // to be in terms of the debug map executable. Either way,
1892                 // calling FixupAddress() will work for us.
1893                 Address exe_so_addr(so_addr);
1894                 if (FixupAddress(exe_so_addr)) {
1895                   if (line_table->FindLineEntryByAddress(exe_so_addr,
1896                                                          sc.line_entry)) {
1897                     resolved |= eSymbolContextLineEntry;
1898                   }
1899                 }
1900               }
1901             }
1902 
1903             if (force_check_line_table &&
1904                 !(resolved & eSymbolContextLineEntry)) {
1905               // We might have had a compile unit that had discontiguous
1906               // address ranges where the gaps are symbols that don't have any
1907               // debug info. Discontiguous compile unit address ranges should
1908               // only happen when there aren't other functions from other
1909               // compile units in these gaps. This helps keep the size of the
1910               // aranges down.
1911               sc.comp_unit = nullptr;
1912               resolved &= ~eSymbolContextCompUnit;
1913             }
1914           } else {
1915             GetObjectFile()->GetModule()->ReportWarning(
1916                 "0x%8.8x: compile unit %u failed to create a valid "
1917                 "lldb_private::CompileUnit class.",
1918                 cu_offset, cu_idx);
1919           }
1920         }
1921       }
1922     }
1923   }
1924   return resolved;
1925 }
1926 
1927 uint32_t SymbolFileDWARF::ResolveSymbolContext(const FileSpec &file_spec,
1928                                                uint32_t line,
1929                                                bool check_inlines,
1930                                                SymbolContextItem resolve_scope,
1931                                                SymbolContextList &sc_list) {
1932   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
1933   const uint32_t prev_size = sc_list.GetSize();
1934   if (resolve_scope & eSymbolContextCompUnit) {
1935     for (uint32_t cu_idx = 0, num_cus = GetNumCompileUnits(); cu_idx < num_cus;
1936          ++cu_idx) {
1937       CompileUnit *dc_cu = ParseCompileUnitAtIndex(cu_idx).get();
1938       if (!dc_cu)
1939         continue;
1940 
1941       bool file_spec_matches_cu_file_spec =
1942           FileSpec::Match(file_spec, dc_cu->GetPrimaryFile());
1943       if (check_inlines || file_spec_matches_cu_file_spec) {
1944         SymbolContext sc(m_objfile_sp->GetModule());
1945         sc.comp_unit = dc_cu;
1946         uint32_t file_idx = UINT32_MAX;
1947 
1948         // If we are looking for inline functions only and we don't find it
1949         // in the support files, we are done.
1950         if (check_inlines) {
1951           file_idx =
1952               sc.comp_unit->GetSupportFiles().FindFileIndex(1, file_spec, true);
1953           if (file_idx == UINT32_MAX)
1954             continue;
1955         }
1956 
1957         if (line != 0) {
1958           LineTable *line_table = sc.comp_unit->GetLineTable();
1959 
1960           if (line_table != nullptr && line != 0) {
1961             // We will have already looked up the file index if we are
1962             // searching for inline entries.
1963             if (!check_inlines)
1964               file_idx = sc.comp_unit->GetSupportFiles().FindFileIndex(
1965                   1, file_spec, true);
1966 
1967             if (file_idx != UINT32_MAX) {
1968               uint32_t found_line;
1969               uint32_t line_idx = line_table->FindLineEntryIndexByFileIndex(
1970                   0, file_idx, line, false, &sc.line_entry);
1971               found_line = sc.line_entry.line;
1972 
1973               while (line_idx != UINT32_MAX) {
1974                 sc.function = nullptr;
1975                 sc.block = nullptr;
1976                 if (resolve_scope &
1977                     (eSymbolContextFunction | eSymbolContextBlock)) {
1978                   const lldb::addr_t file_vm_addr =
1979                       sc.line_entry.range.GetBaseAddress().GetFileAddress();
1980                   if (file_vm_addr != LLDB_INVALID_ADDRESS) {
1981                     DWARFDIE function_die =
1982                         GetDWARFCompileUnit(dc_cu)->LookupAddress(file_vm_addr);
1983                     DWARFDIE block_die;
1984                     if (function_die) {
1985                       sc.function =
1986                           sc.comp_unit->FindFunctionByUID(function_die.GetID())
1987                               .get();
1988                       if (sc.function == nullptr)
1989                         sc.function =
1990                             ParseFunction(*sc.comp_unit, function_die);
1991 
1992                       if (sc.function && (resolve_scope & eSymbolContextBlock))
1993                         block_die =
1994                             function_die.LookupDeepestBlock(file_vm_addr);
1995                     }
1996 
1997                     if (sc.function != nullptr) {
1998                       Block &block = sc.function->GetBlock(true);
1999 
2000                       if (block_die)
2001                         sc.block = block.FindBlockByID(block_die.GetID());
2002                       else if (function_die)
2003                         sc.block = block.FindBlockByID(function_die.GetID());
2004                     }
2005                   }
2006                 }
2007 
2008                 sc_list.Append(sc);
2009                 line_idx = line_table->FindLineEntryIndexByFileIndex(
2010                     line_idx + 1, file_idx, found_line, true, &sc.line_entry);
2011               }
2012             }
2013           } else if (file_spec_matches_cu_file_spec && !check_inlines) {
2014             // only append the context if we aren't looking for inline call
2015             // sites by file and line and if the file spec matches that of
2016             // the compile unit
2017             sc_list.Append(sc);
2018           }
2019         } else if (file_spec_matches_cu_file_spec && !check_inlines) {
2020           // only append the context if we aren't looking for inline call
2021           // sites by file and line and if the file spec matches that of
2022           // the compile unit
2023           sc_list.Append(sc);
2024         }
2025 
2026         if (!check_inlines)
2027           break;
2028       }
2029     }
2030   }
2031   return sc_list.GetSize() - prev_size;
2032 }
2033 
2034 void SymbolFileDWARF::PreloadSymbols() {
2035   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2036   m_index->Preload();
2037 }
2038 
2039 std::recursive_mutex &SymbolFileDWARF::GetModuleMutex() const {
2040   lldb::ModuleSP module_sp(m_debug_map_module_wp.lock());
2041   if (module_sp)
2042     return module_sp->GetMutex();
2043   return GetObjectFile()->GetModule()->GetMutex();
2044 }
2045 
2046 bool SymbolFileDWARF::DeclContextMatchesThisSymbolFile(
2047     const lldb_private::CompilerDeclContext *decl_ctx) {
2048   if (decl_ctx == nullptr || !decl_ctx->IsValid()) {
2049     // Invalid namespace decl which means we aren't matching only things in
2050     // this symbol file, so return true to indicate it matches this symbol
2051     // file.
2052     return true;
2053   }
2054 
2055   TypeSystem *decl_ctx_type_system = decl_ctx->GetTypeSystem();
2056   auto type_system_or_err = GetTypeSystemForLanguage(
2057       decl_ctx_type_system->GetMinimumLanguage(nullptr));
2058   if (auto err = type_system_or_err.takeError()) {
2059     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
2060                    std::move(err),
2061                    "Unable to match namespace decl using TypeSystem");
2062     return false;
2063   }
2064 
2065   if (decl_ctx_type_system == &type_system_or_err.get())
2066     return true; // The type systems match, return true
2067 
2068   // The namespace AST was valid, and it does not match...
2069   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2070 
2071   if (log)
2072     GetObjectFile()->GetModule()->LogMessage(
2073         log, "Valid namespace does not match symbol file");
2074 
2075   return false;
2076 }
2077 
2078 void SymbolFileDWARF::FindGlobalVariables(
2079     ConstString name, const CompilerDeclContext *parent_decl_ctx,
2080     uint32_t max_matches, VariableList &variables) {
2081   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2082   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2083 
2084   if (log)
2085     GetObjectFile()->GetModule()->LogMessage(
2086         log,
2087         "SymbolFileDWARF::FindGlobalVariables (name=\"%s\", "
2088         "parent_decl_ctx=%p, max_matches=%u, variables)",
2089         name.GetCString(), static_cast<const void *>(parent_decl_ctx),
2090         max_matches);
2091 
2092   if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
2093     return;
2094 
2095   DWARFDebugInfo *info = DebugInfo();
2096   if (!info)
2097     return;
2098 
2099   // Remember how many variables are in the list before we search.
2100   const uint32_t original_size = variables.GetSize();
2101 
2102   llvm::StringRef basename;
2103   llvm::StringRef context;
2104   bool name_is_mangled = (bool)Mangled(name);
2105 
2106   if (!CPlusPlusLanguage::ExtractContextAndIdentifier(name.GetCString(),
2107                                                       context, basename))
2108     basename = name.GetStringRef();
2109 
2110   DIEArray die_offsets;
2111   m_index->GetGlobalVariables(ConstString(basename), die_offsets);
2112   const size_t num_die_matches = die_offsets.size();
2113   if (num_die_matches) {
2114     SymbolContext sc;
2115     sc.module_sp = m_objfile_sp->GetModule();
2116     assert(sc.module_sp);
2117 
2118     // Loop invariant: Variables up to this index have been checked for context
2119     // matches.
2120     uint32_t pruned_idx = original_size;
2121 
2122     bool done = false;
2123     for (size_t i = 0; i < num_die_matches && !done; ++i) {
2124       const DIERef &die_ref = die_offsets[i];
2125       DWARFDIE die = GetDIE(die_ref);
2126 
2127       if (die) {
2128         switch (die.Tag()) {
2129         default:
2130         case DW_TAG_subprogram:
2131         case DW_TAG_inlined_subroutine:
2132         case DW_TAG_try_block:
2133         case DW_TAG_catch_block:
2134           break;
2135 
2136         case DW_TAG_variable: {
2137           auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(die.GetCU());
2138           if (!dwarf_cu)
2139             continue;
2140           sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
2141 
2142           if (parent_decl_ctx) {
2143             DWARFASTParser *dwarf_ast = die.GetDWARFParser();
2144             if (dwarf_ast) {
2145               CompilerDeclContext actual_parent_decl_ctx =
2146                   dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
2147               if (!actual_parent_decl_ctx ||
2148                   actual_parent_decl_ctx != *parent_decl_ctx)
2149                 continue;
2150             }
2151           }
2152 
2153           ParseVariables(sc, die, LLDB_INVALID_ADDRESS, false, false,
2154                          &variables);
2155           while (pruned_idx < variables.GetSize()) {
2156             VariableSP var_sp = variables.GetVariableAtIndex(pruned_idx);
2157             if (name_is_mangled ||
2158                 var_sp->GetName().GetStringRef().contains(name.GetStringRef()))
2159               ++pruned_idx;
2160             else
2161               variables.RemoveVariableAtIndex(pruned_idx);
2162           }
2163 
2164           if (variables.GetSize() - original_size >= max_matches)
2165             done = true;
2166         } break;
2167         }
2168       } else {
2169         m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
2170       }
2171     }
2172   }
2173 
2174   // Return the number of variable that were appended to the list
2175   const uint32_t num_matches = variables.GetSize() - original_size;
2176   if (log && num_matches > 0) {
2177     GetObjectFile()->GetModule()->LogMessage(
2178         log,
2179         "SymbolFileDWARF::FindGlobalVariables (name=\"%s\", "
2180         "parent_decl_ctx=%p, max_matches=%u, variables) => %u",
2181         name.GetCString(), static_cast<const void *>(parent_decl_ctx),
2182         max_matches, num_matches);
2183   }
2184 }
2185 
2186 void SymbolFileDWARF::FindGlobalVariables(const RegularExpression &regex,
2187                                           uint32_t max_matches,
2188                                           VariableList &variables) {
2189   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2190   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2191 
2192   if (log) {
2193     GetObjectFile()->GetModule()->LogMessage(
2194         log,
2195         "SymbolFileDWARF::FindGlobalVariables (regex=\"%s\", "
2196         "max_matches=%u, variables)",
2197         regex.GetText().str().c_str(), max_matches);
2198   }
2199 
2200   DWARFDebugInfo *info = DebugInfo();
2201   if (!info)
2202     return;
2203 
2204   // Remember how many variables are in the list before we search.
2205   const uint32_t original_size = variables.GetSize();
2206 
2207   DIEArray die_offsets;
2208   m_index->GetGlobalVariables(regex, die_offsets);
2209 
2210   SymbolContext sc;
2211   sc.module_sp = m_objfile_sp->GetModule();
2212   assert(sc.module_sp);
2213 
2214   const size_t num_matches = die_offsets.size();
2215   if (num_matches) {
2216     for (size_t i = 0; i < num_matches; ++i) {
2217       const DIERef &die_ref = die_offsets[i];
2218       DWARFDIE die = GetDIE(die_ref);
2219 
2220       if (die) {
2221         DWARFCompileUnit *dwarf_cu =
2222             llvm::dyn_cast<DWARFCompileUnit>(die.GetCU());
2223         if (!dwarf_cu)
2224           continue;
2225         sc.comp_unit = GetCompUnitForDWARFCompUnit(*dwarf_cu);
2226 
2227         ParseVariables(sc, die, LLDB_INVALID_ADDRESS, false, false, &variables);
2228 
2229         if (variables.GetSize() - original_size >= max_matches)
2230           break;
2231       } else
2232         m_index->ReportInvalidDIERef(die_ref, regex.GetText());
2233     }
2234   }
2235 }
2236 
2237 bool SymbolFileDWARF::ResolveFunction(const DWARFDIE &orig_die,
2238                                       bool include_inlines,
2239                                       SymbolContextList &sc_list) {
2240   SymbolContext sc;
2241 
2242   if (!orig_die)
2243     return false;
2244 
2245   // If we were passed a die that is not a function, just return false...
2246   if (!(orig_die.Tag() == DW_TAG_subprogram ||
2247         (include_inlines && orig_die.Tag() == DW_TAG_inlined_subroutine)))
2248     return false;
2249 
2250   DWARFDIE die = orig_die;
2251   DWARFDIE inlined_die;
2252   if (die.Tag() == DW_TAG_inlined_subroutine) {
2253     inlined_die = die;
2254 
2255     while (true) {
2256       die = die.GetParent();
2257 
2258       if (die) {
2259         if (die.Tag() == DW_TAG_subprogram)
2260           break;
2261       } else
2262         break;
2263     }
2264   }
2265   assert(die && die.Tag() == DW_TAG_subprogram);
2266   if (GetFunction(die, sc)) {
2267     Address addr;
2268     // Parse all blocks if needed
2269     if (inlined_die) {
2270       Block &function_block = sc.function->GetBlock(true);
2271       sc.block = function_block.FindBlockByID(inlined_die.GetID());
2272       if (sc.block == nullptr)
2273         sc.block = function_block.FindBlockByID(inlined_die.GetOffset());
2274       if (sc.block == nullptr || !sc.block->GetStartAddress(addr))
2275         addr.Clear();
2276     } else {
2277       sc.block = nullptr;
2278       addr = sc.function->GetAddressRange().GetBaseAddress();
2279     }
2280 
2281 
2282     if (auto section_sp = addr.GetSection()) {
2283       if (section_sp->GetPermissions() & ePermissionsExecutable) {
2284         sc_list.Append(sc);
2285         return true;
2286       }
2287     }
2288   }
2289 
2290   return false;
2291 }
2292 
2293 bool SymbolFileDWARF::DIEInDeclContext(const CompilerDeclContext *decl_ctx,
2294                                        const DWARFDIE &die) {
2295   // If we have no parent decl context to match this DIE matches, and if the
2296   // parent decl context isn't valid, we aren't trying to look for any
2297   // particular decl context so any die matches.
2298   if (decl_ctx == nullptr || !decl_ctx->IsValid())
2299     return true;
2300 
2301   if (die) {
2302     DWARFASTParser *dwarf_ast = die.GetDWARFParser();
2303     if (dwarf_ast) {
2304       CompilerDeclContext actual_decl_ctx =
2305           dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);
2306       if (actual_decl_ctx)
2307         return decl_ctx->IsContainedInLookup(actual_decl_ctx);
2308     }
2309   }
2310   return false;
2311 }
2312 
2313 void SymbolFileDWARF::FindFunctions(ConstString name,
2314                                     const CompilerDeclContext *parent_decl_ctx,
2315                                     FunctionNameType name_type_mask,
2316                                     bool include_inlines,
2317                                     SymbolContextList &sc_list) {
2318   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2319   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
2320   Timer scoped_timer(func_cat, "SymbolFileDWARF::FindFunctions (name = '%s')",
2321                      name.AsCString());
2322 
2323   // eFunctionNameTypeAuto should be pre-resolved by a call to
2324   // Module::LookupInfo::LookupInfo()
2325   assert((name_type_mask & eFunctionNameTypeAuto) == 0);
2326 
2327   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2328 
2329   if (log) {
2330     GetObjectFile()->GetModule()->LogMessage(
2331         log,
2332         "SymbolFileDWARF::FindFunctions (name=\"%s\", name_type_mask=0x%x, sc_list)",
2333         name.GetCString(), name_type_mask);
2334   }
2335 
2336   if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
2337     return;
2338 
2339   // If name is empty then we won't find anything.
2340   if (name.IsEmpty())
2341     return;
2342 
2343   // Remember how many sc_list are in the list before we search in case we are
2344   // appending the results to a variable list.
2345 
2346   const uint32_t original_size = sc_list.GetSize();
2347 
2348   llvm::DenseSet<const DWARFDebugInfoEntry *> resolved_dies;
2349   DIEArray offsets;
2350   CompilerDeclContext empty_decl_ctx;
2351   if (!parent_decl_ctx)
2352     parent_decl_ctx = &empty_decl_ctx;
2353 
2354   std::vector<DWARFDIE> dies;
2355   m_index->GetFunctions(name, *this, *parent_decl_ctx, name_type_mask, dies);
2356   for (const DWARFDIE &die : dies) {
2357     if (resolved_dies.insert(die.GetDIE()).second)
2358       ResolveFunction(die, include_inlines, sc_list);
2359   }
2360 
2361   // Return the number of variable that were appended to the list
2362   const uint32_t num_matches = sc_list.GetSize() - original_size;
2363 
2364   if (log && num_matches > 0) {
2365     GetObjectFile()->GetModule()->LogMessage(
2366         log,
2367         "SymbolFileDWARF::FindFunctions (name=\"%s\", "
2368         "name_type_mask=0x%x, include_inlines=%d, sc_list) => %u",
2369         name.GetCString(), name_type_mask, include_inlines,
2370         num_matches);
2371   }
2372 }
2373 
2374 void SymbolFileDWARF::FindFunctions(const RegularExpression &regex,
2375                                     bool include_inlines,
2376                                     SymbolContextList &sc_list) {
2377   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2378   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
2379   Timer scoped_timer(func_cat, "SymbolFileDWARF::FindFunctions (regex = '%s')",
2380                      regex.GetText().str().c_str());
2381 
2382   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2383 
2384   if (log) {
2385     GetObjectFile()->GetModule()->LogMessage(
2386         log, "SymbolFileDWARF::FindFunctions (regex=\"%s\", sc_list)",
2387         regex.GetText().str().c_str());
2388   }
2389 
2390   DWARFDebugInfo *info = DebugInfo();
2391   if (!info)
2392     return;
2393 
2394   DIEArray offsets;
2395   m_index->GetFunctions(regex, offsets);
2396 
2397   llvm::DenseSet<const DWARFDebugInfoEntry *> resolved_dies;
2398   for (DIERef ref : offsets) {
2399     DWARFDIE die = info->GetDIE(ref);
2400     if (!die) {
2401       m_index->ReportInvalidDIERef(ref, regex.GetText());
2402       continue;
2403     }
2404     if (resolved_dies.insert(die.GetDIE()).second)
2405       ResolveFunction(die, include_inlines, sc_list);
2406   }
2407 }
2408 
2409 void SymbolFileDWARF::GetMangledNamesForFunction(
2410     const std::string &scope_qualified_name,
2411     std::vector<ConstString> &mangled_names) {
2412   DWARFDebugInfo *info = DebugInfo();
2413   uint32_t num_comp_units = 0;
2414   if (info)
2415     num_comp_units = info->GetNumUnits();
2416 
2417   for (uint32_t i = 0; i < num_comp_units; i++) {
2418     DWARFUnit *cu = info->GetUnitAtIndex(i);
2419     if (cu == nullptr)
2420       continue;
2421 
2422     SymbolFileDWARFDwo *dwo = cu->GetDwoSymbolFile();
2423     if (dwo)
2424       dwo->GetMangledNamesForFunction(scope_qualified_name, mangled_names);
2425   }
2426 
2427   for (lldb::user_id_t uid :
2428        m_function_scope_qualified_name_map.lookup(scope_qualified_name)) {
2429     DWARFDIE die = GetDIE(uid);
2430     mangled_names.push_back(ConstString(die.GetMangledName()));
2431   }
2432 }
2433 
2434 void SymbolFileDWARF::FindTypes(
2435     ConstString name, const CompilerDeclContext *parent_decl_ctx,
2436     uint32_t max_matches,
2437     llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
2438     TypeMap &types) {
2439   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2440   // Make sure we haven't already searched this SymbolFile before.
2441   if (!searched_symbol_files.insert(this).second)
2442     return;
2443 
2444   DWARFDebugInfo *info = DebugInfo();
2445   if (!info)
2446     return;
2447 
2448   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2449 
2450   if (log) {
2451     if (parent_decl_ctx)
2452       GetObjectFile()->GetModule()->LogMessage(
2453           log,
2454           "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx = "
2455           "%p (\"%s\"), max_matches=%u, type_list)",
2456           name.GetCString(), static_cast<const void *>(parent_decl_ctx),
2457           parent_decl_ctx->GetName().AsCString("<NULL>"), max_matches);
2458     else
2459       GetObjectFile()->GetModule()->LogMessage(
2460           log,
2461           "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx = "
2462           "NULL, max_matches=%u, type_list)",
2463           name.GetCString(), max_matches);
2464   }
2465 
2466   if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
2467     return;
2468 
2469   DIEArray die_offsets;
2470   m_index->GetTypes(name, die_offsets);
2471   const size_t num_die_matches = die_offsets.size();
2472 
2473   for (size_t i = 0; i < num_die_matches; ++i) {
2474     const DIERef &die_ref = die_offsets[i];
2475     DWARFDIE die = GetDIE(die_ref);
2476     if (die) {
2477       if (!DIEInDeclContext(parent_decl_ctx, die))
2478         continue; // The containing decl contexts don't match
2479 
2480       Type *matching_type = ResolveType(die, true, true);
2481       if (matching_type) {
2482         // We found a type pointer, now find the shared pointer form our type
2483         // list
2484         types.InsertUnique(matching_type->shared_from_this());
2485         if (types.GetSize() >= max_matches)
2486           break;
2487       }
2488     } else {
2489       m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
2490     }
2491   }
2492 
2493   // Next search through the reachable Clang modules. This only applies for
2494   // DWARF objects compiled with -gmodules that haven't been processed by
2495   // dsymutil.
2496   if (num_die_matches < max_matches) {
2497     UpdateExternalModuleListIfNeeded();
2498 
2499     for (const auto &pair : m_external_type_modules)
2500       if (ModuleSP external_module_sp = pair.second)
2501         if (SymbolFile *sym_file = external_module_sp->GetSymbolFile())
2502           sym_file->FindTypes(name, parent_decl_ctx, max_matches,
2503                               searched_symbol_files, types);
2504   }
2505 
2506   if (log && types.GetSize()) {
2507     if (parent_decl_ctx) {
2508       GetObjectFile()->GetModule()->LogMessage(
2509           log,
2510           "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx "
2511           "= %p (\"%s\"), max_matches=%u, type_list) => %u",
2512           name.GetCString(), static_cast<const void *>(parent_decl_ctx),
2513           parent_decl_ctx->GetName().AsCString("<NULL>"), max_matches,
2514           types.GetSize());
2515     } else {
2516       GetObjectFile()->GetModule()->LogMessage(
2517           log,
2518           "SymbolFileDWARF::FindTypes (sc, name=\"%s\", parent_decl_ctx "
2519           "= NULL, max_matches=%u, type_list) => %u",
2520           name.GetCString(), max_matches, types.GetSize());
2521     }
2522   }
2523 }
2524 
2525 void SymbolFileDWARF::FindTypes(
2526     llvm::ArrayRef<CompilerContext> pattern, LanguageSet languages,
2527     llvm::DenseSet<SymbolFile *> &searched_symbol_files, TypeMap &types) {
2528   // Make sure we haven't already searched this SymbolFile before.
2529   if (!searched_symbol_files.insert(this).second)
2530     return;
2531 
2532   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2533   if (pattern.empty())
2534     return;
2535 
2536   ConstString name = pattern.back().name;
2537 
2538   if (!name)
2539     return;
2540 
2541   DIEArray die_offsets;
2542   m_index->GetTypes(name, die_offsets);
2543   const size_t num_die_matches = die_offsets.size();
2544 
2545   for (size_t i = 0; i < num_die_matches; ++i) {
2546     const DIERef &die_ref = die_offsets[i];
2547     DWARFDIE die = GetDIE(die_ref);
2548 
2549     if (!die) {
2550       m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
2551       continue;
2552     }
2553     if (!languages[die.GetCU()->GetLanguageType()])
2554       continue;
2555 
2556     llvm::SmallVector<CompilerContext, 4> die_context;
2557     die.GetDeclContext(die_context);
2558     if (!contextMatches(die_context, pattern))
2559       continue;
2560 
2561     if (Type *matching_type = ResolveType(die, true, true)) {
2562       // We found a type pointer, now find the shared pointer form our type
2563       // list.
2564       types.InsertUnique(matching_type->shared_from_this());
2565     }
2566   }
2567 
2568   // Next search through the reachable Clang modules. This only applies for
2569   // DWARF objects compiled with -gmodules that haven't been processed by
2570   // dsymutil.
2571   UpdateExternalModuleListIfNeeded();
2572 
2573   for (const auto &pair : m_external_type_modules)
2574     if (ModuleSP external_module_sp = pair.second)
2575       external_module_sp->FindTypes(pattern, languages, searched_symbol_files,
2576                                     types);
2577 }
2578 
2579 CompilerDeclContext
2580 SymbolFileDWARF::FindNamespace(ConstString name,
2581                                const CompilerDeclContext *parent_decl_ctx) {
2582   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
2583   Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS));
2584 
2585   if (log) {
2586     GetObjectFile()->GetModule()->LogMessage(
2587         log, "SymbolFileDWARF::FindNamespace (sc, name=\"%s\")",
2588         name.GetCString());
2589   }
2590 
2591   CompilerDeclContext namespace_decl_ctx;
2592 
2593   if (!DeclContextMatchesThisSymbolFile(parent_decl_ctx))
2594     return namespace_decl_ctx;
2595 
2596   DWARFDebugInfo *info = DebugInfo();
2597   if (info) {
2598     DIEArray die_offsets;
2599     m_index->GetNamespaces(name, die_offsets);
2600     const size_t num_matches = die_offsets.size();
2601     if (num_matches) {
2602       for (size_t i = 0; i < num_matches; ++i) {
2603         const DIERef &die_ref = die_offsets[i];
2604         DWARFDIE die = GetDIE(die_ref);
2605 
2606         if (die) {
2607           if (!DIEInDeclContext(parent_decl_ctx, die))
2608             continue; // The containing decl contexts don't match
2609 
2610           DWARFASTParser *dwarf_ast = die.GetDWARFParser();
2611           if (dwarf_ast) {
2612             namespace_decl_ctx = dwarf_ast->GetDeclContextForUIDFromDWARF(die);
2613             if (namespace_decl_ctx)
2614               break;
2615           }
2616         } else {
2617           m_index->ReportInvalidDIERef(die_ref, name.GetStringRef());
2618         }
2619       }
2620     }
2621   }
2622   if (log && namespace_decl_ctx) {
2623     GetObjectFile()->GetModule()->LogMessage(
2624         log,
2625         "SymbolFileDWARF::FindNamespace (sc, name=\"%s\") => "
2626         "CompilerDeclContext(%p/%p) \"%s\"",
2627         name.GetCString(),
2628         static_cast<const void *>(namespace_decl_ctx.GetTypeSystem()),
2629         static_cast<const void *>(namespace_decl_ctx.GetOpaqueDeclContext()),
2630         namespace_decl_ctx.GetName().AsCString("<NULL>"));
2631   }
2632 
2633   return namespace_decl_ctx;
2634 }
2635 
2636 TypeSP SymbolFileDWARF::GetTypeForDIE(const DWARFDIE &die,
2637                                       bool resolve_function_context) {
2638   TypeSP type_sp;
2639   if (die) {
2640     Type *type_ptr = GetDIEToType().lookup(die.GetDIE());
2641     if (type_ptr == nullptr) {
2642       SymbolContextScope *scope;
2643       if (auto *dwarf_cu = llvm::dyn_cast<DWARFCompileUnit>(die.GetCU()))
2644         scope = GetCompUnitForDWARFCompUnit(*dwarf_cu);
2645       else
2646         scope = GetObjectFile()->GetModule().get();
2647       assert(scope);
2648       SymbolContext sc(scope);
2649       const DWARFDebugInfoEntry *parent_die = die.GetParent().GetDIE();
2650       while (parent_die != nullptr) {
2651         if (parent_die->Tag() == DW_TAG_subprogram)
2652           break;
2653         parent_die = parent_die->GetParent();
2654       }
2655       SymbolContext sc_backup = sc;
2656       if (resolve_function_context && parent_die != nullptr &&
2657           !GetFunction(DWARFDIE(die.GetCU(), parent_die), sc))
2658         sc = sc_backup;
2659 
2660       type_sp = ParseType(sc, die, nullptr);
2661     } else if (type_ptr != DIE_IS_BEING_PARSED) {
2662       // Grab the existing type from the master types lists
2663       type_sp = type_ptr->shared_from_this();
2664     }
2665   }
2666   return type_sp;
2667 }
2668 
2669 DWARFDIE
2670 SymbolFileDWARF::GetDeclContextDIEContainingDIE(const DWARFDIE &orig_die) {
2671   if (orig_die) {
2672     DWARFDIE die = orig_die;
2673 
2674     while (die) {
2675       // If this is the original DIE that we are searching for a declaration
2676       // for, then don't look in the cache as we don't want our own decl
2677       // context to be our decl context...
2678       if (orig_die != die) {
2679         switch (die.Tag()) {
2680         case DW_TAG_compile_unit:
2681         case DW_TAG_partial_unit:
2682         case DW_TAG_namespace:
2683         case DW_TAG_structure_type:
2684         case DW_TAG_union_type:
2685         case DW_TAG_class_type:
2686         case DW_TAG_lexical_block:
2687         case DW_TAG_subprogram:
2688           return die;
2689         case DW_TAG_inlined_subroutine: {
2690           DWARFDIE abs_die = die.GetReferencedDIE(DW_AT_abstract_origin);
2691           if (abs_die) {
2692             return abs_die;
2693           }
2694           break;
2695         }
2696         default:
2697           break;
2698         }
2699       }
2700 
2701       DWARFDIE spec_die = die.GetReferencedDIE(DW_AT_specification);
2702       if (spec_die) {
2703         DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(spec_die);
2704         if (decl_ctx_die)
2705           return decl_ctx_die;
2706       }
2707 
2708       DWARFDIE abs_die = die.GetReferencedDIE(DW_AT_abstract_origin);
2709       if (abs_die) {
2710         DWARFDIE decl_ctx_die = GetDeclContextDIEContainingDIE(abs_die);
2711         if (decl_ctx_die)
2712           return decl_ctx_die;
2713       }
2714 
2715       die = die.GetParent();
2716     }
2717   }
2718   return DWARFDIE();
2719 }
2720 
2721 Symbol *SymbolFileDWARF::GetObjCClassSymbol(ConstString objc_class_name) {
2722   Symbol *objc_class_symbol = nullptr;
2723   if (m_objfile_sp) {
2724     Symtab *symtab = m_objfile_sp->GetSymtab();
2725     if (symtab) {
2726       objc_class_symbol = symtab->FindFirstSymbolWithNameAndType(
2727           objc_class_name, eSymbolTypeObjCClass, Symtab::eDebugNo,
2728           Symtab::eVisibilityAny);
2729     }
2730   }
2731   return objc_class_symbol;
2732 }
2733 
2734 // Some compilers don't emit the DW_AT_APPLE_objc_complete_type attribute. If
2735 // they don't then we can end up looking through all class types for a complete
2736 // type and never find the full definition. We need to know if this attribute
2737 // is supported, so we determine this here and cache th result. We also need to
2738 // worry about the debug map
2739 // DWARF file
2740 // if we are doing darwin DWARF in .o file debugging.
2741 bool SymbolFileDWARF::Supports_DW_AT_APPLE_objc_complete_type(DWARFUnit *cu) {
2742   if (m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolCalculate) {
2743     m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolNo;
2744     if (cu && cu->Supports_DW_AT_APPLE_objc_complete_type())
2745       m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolYes;
2746     else {
2747       DWARFDebugInfo *debug_info = DebugInfo();
2748       const uint32_t num_compile_units = GetNumCompileUnits();
2749       for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
2750         DWARFUnit *dwarf_cu = debug_info->GetUnitAtIndex(cu_idx);
2751         if (dwarf_cu != cu &&
2752             dwarf_cu->Supports_DW_AT_APPLE_objc_complete_type()) {
2753           m_supports_DW_AT_APPLE_objc_complete_type = eLazyBoolYes;
2754           break;
2755         }
2756       }
2757     }
2758     if (m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolNo &&
2759         GetDebugMapSymfile())
2760       return m_debug_map_symfile->Supports_DW_AT_APPLE_objc_complete_type(this);
2761   }
2762   return m_supports_DW_AT_APPLE_objc_complete_type == eLazyBoolYes;
2763 }
2764 
2765 // This function can be used when a DIE is found that is a forward declaration
2766 // DIE and we want to try and find a type that has the complete definition.
2767 TypeSP SymbolFileDWARF::FindCompleteObjCDefinitionTypeForDIE(
2768     const DWARFDIE &die, ConstString type_name, bool must_be_implementation) {
2769 
2770   TypeSP type_sp;
2771 
2772   if (!type_name || (must_be_implementation && !GetObjCClassSymbol(type_name)))
2773     return type_sp;
2774 
2775   DIEArray die_offsets;
2776   m_index->GetCompleteObjCClass(type_name, must_be_implementation, die_offsets);
2777 
2778   const size_t num_matches = die_offsets.size();
2779 
2780   if (num_matches) {
2781     for (size_t i = 0; i < num_matches; ++i) {
2782       const DIERef &die_ref = die_offsets[i];
2783       DWARFDIE type_die = GetDIE(die_ref);
2784 
2785       if (type_die) {
2786         bool try_resolving_type = false;
2787 
2788         // Don't try and resolve the DIE we are looking for with the DIE
2789         // itself!
2790         if (type_die != die) {
2791           switch (type_die.Tag()) {
2792           case DW_TAG_class_type:
2793           case DW_TAG_structure_type:
2794             try_resolving_type = true;
2795             break;
2796           default:
2797             break;
2798           }
2799         }
2800 
2801         if (try_resolving_type) {
2802           if (must_be_implementation &&
2803               type_die.Supports_DW_AT_APPLE_objc_complete_type())
2804             try_resolving_type = type_die.GetAttributeValueAsUnsigned(
2805                 DW_AT_APPLE_objc_complete_type, 0);
2806 
2807           if (try_resolving_type) {
2808             Type *resolved_type = ResolveType(type_die, false, true);
2809             if (resolved_type && resolved_type != DIE_IS_BEING_PARSED) {
2810               DEBUG_PRINTF("resolved 0x%8.8" PRIx64 " from %s to 0x%8.8" PRIx64
2811                            " (cu 0x%8.8" PRIx64 ")\n",
2812                            die.GetID(),
2813                            m_objfile_sp->GetFileSpec().GetFilename().AsCString(
2814                                "<Unknown>"),
2815                            type_die.GetID(), type_cu->GetID());
2816 
2817               if (die)
2818                 GetDIEToType()[die.GetDIE()] = resolved_type;
2819               type_sp = resolved_type->shared_from_this();
2820               break;
2821             }
2822           }
2823         }
2824       } else {
2825         m_index->ReportInvalidDIERef(die_ref, type_name.GetStringRef());
2826       }
2827     }
2828   }
2829   return type_sp;
2830 }
2831 
2832 // This function helps to ensure that the declaration contexts match for two
2833 // different DIEs. Often times debug information will refer to a forward
2834 // declaration of a type (the equivalent of "struct my_struct;". There will
2835 // often be a declaration of that type elsewhere that has the full definition.
2836 // When we go looking for the full type "my_struct", we will find one or more
2837 // matches in the accelerator tables and we will then need to make sure the
2838 // type was in the same declaration context as the original DIE. This function
2839 // can efficiently compare two DIEs and will return true when the declaration
2840 // context matches, and false when they don't.
2841 bool SymbolFileDWARF::DIEDeclContextsMatch(const DWARFDIE &die1,
2842                                            const DWARFDIE &die2) {
2843   if (die1 == die2)
2844     return true;
2845 
2846   std::vector<DWARFDIE> decl_ctx_1;
2847   std::vector<DWARFDIE> decl_ctx_2;
2848   // The declaration DIE stack is a stack of the declaration context DIEs all
2849   // the way back to the compile unit. If a type "T" is declared inside a class
2850   // "B", and class "B" is declared inside a class "A" and class "A" is in a
2851   // namespace "lldb", and the namespace is in a compile unit, there will be a
2852   // stack of DIEs:
2853   //
2854   //   [0] DW_TAG_class_type for "B"
2855   //   [1] DW_TAG_class_type for "A"
2856   //   [2] DW_TAG_namespace  for "lldb"
2857   //   [3] DW_TAG_compile_unit or DW_TAG_partial_unit for the source file.
2858   //
2859   // We grab both contexts and make sure that everything matches all the way
2860   // back to the compiler unit.
2861 
2862   // First lets grab the decl contexts for both DIEs
2863   decl_ctx_1 = die1.GetDeclContextDIEs();
2864   decl_ctx_2 = die2.GetDeclContextDIEs();
2865   // Make sure the context arrays have the same size, otherwise we are done
2866   const size_t count1 = decl_ctx_1.size();
2867   const size_t count2 = decl_ctx_2.size();
2868   if (count1 != count2)
2869     return false;
2870 
2871   // Make sure the DW_TAG values match all the way back up the compile unit. If
2872   // they don't, then we are done.
2873   DWARFDIE decl_ctx_die1;
2874   DWARFDIE decl_ctx_die2;
2875   size_t i;
2876   for (i = 0; i < count1; i++) {
2877     decl_ctx_die1 = decl_ctx_1[i];
2878     decl_ctx_die2 = decl_ctx_2[i];
2879     if (decl_ctx_die1.Tag() != decl_ctx_die2.Tag())
2880       return false;
2881   }
2882 #ifndef NDEBUG
2883 
2884   // Make sure the top item in the decl context die array is always
2885   // DW_TAG_compile_unit or DW_TAG_partial_unit. If it isn't then
2886   // something went wrong in the DWARFDIE::GetDeclContextDIEs()
2887   // function.
2888   dw_tag_t cu_tag = decl_ctx_1[count1 - 1].Tag();
2889   UNUSED_IF_ASSERT_DISABLED(cu_tag);
2890   assert(cu_tag == DW_TAG_compile_unit || cu_tag == DW_TAG_partial_unit);
2891 
2892 #endif
2893   // Always skip the compile unit when comparing by only iterating up to "count
2894   // - 1". Here we compare the names as we go.
2895   for (i = 0; i < count1 - 1; i++) {
2896     decl_ctx_die1 = decl_ctx_1[i];
2897     decl_ctx_die2 = decl_ctx_2[i];
2898     const char *name1 = decl_ctx_die1.GetName();
2899     const char *name2 = decl_ctx_die2.GetName();
2900     // If the string was from a DW_FORM_strp, then the pointer will often be
2901     // the same!
2902     if (name1 == name2)
2903       continue;
2904 
2905     // Name pointers are not equal, so only compare the strings if both are not
2906     // NULL.
2907     if (name1 && name2) {
2908       // If the strings don't compare, we are done...
2909       if (strcmp(name1, name2) != 0)
2910         return false;
2911     } else {
2912       // One name was NULL while the other wasn't
2913       return false;
2914     }
2915   }
2916   // We made it through all of the checks and the declaration contexts are
2917   // equal.
2918   return true;
2919 }
2920 
2921 TypeSP SymbolFileDWARF::FindDefinitionTypeForDWARFDeclContext(
2922     const DWARFDeclContext &dwarf_decl_ctx) {
2923   TypeSP type_sp;
2924 
2925   const uint32_t dwarf_decl_ctx_count = dwarf_decl_ctx.GetSize();
2926   if (dwarf_decl_ctx_count > 0) {
2927     const ConstString type_name(dwarf_decl_ctx[0].name);
2928     const dw_tag_t tag = dwarf_decl_ctx[0].tag;
2929 
2930     if (type_name) {
2931       Log *log(LogChannelDWARF::GetLogIfAny(DWARF_LOG_TYPE_COMPLETION |
2932                                             DWARF_LOG_LOOKUPS));
2933       if (log) {
2934         GetObjectFile()->GetModule()->LogMessage(
2935             log,
2936             "SymbolFileDWARF::FindDefinitionTypeForDWARFDeclContext(tag=%"
2937             "s, qualified-name='%s')",
2938             DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
2939             dwarf_decl_ctx.GetQualifiedName());
2940       }
2941 
2942       DIEArray die_offsets;
2943       m_index->GetTypes(dwarf_decl_ctx, die_offsets);
2944       const size_t num_matches = die_offsets.size();
2945 
2946       // Get the type system that we are looking to find a type for. We will
2947       // use this to ensure any matches we find are in a language that this
2948       // type system supports
2949       const LanguageType language = dwarf_decl_ctx.GetLanguage();
2950       TypeSystem *type_system = nullptr;
2951       if (language != eLanguageTypeUnknown) {
2952         auto type_system_or_err = GetTypeSystemForLanguage(language);
2953         if (auto err = type_system_or_err.takeError()) {
2954           LLDB_LOG_ERROR(
2955               lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
2956               std::move(err), "Cannot get TypeSystem for language {}",
2957               Language::GetNameForLanguageType(language));
2958         } else {
2959           type_system = &type_system_or_err.get();
2960         }
2961       }
2962       if (num_matches) {
2963         for (size_t i = 0; i < num_matches; ++i) {
2964           const DIERef &die_ref = die_offsets[i];
2965           DWARFDIE type_die = GetDIE(die_ref);
2966 
2967           if (type_die) {
2968             // Make sure type_die's langauge matches the type system we are
2969             // looking for. We don't want to find a "Foo" type from Java if we
2970             // are looking for a "Foo" type for C, C++, ObjC, or ObjC++.
2971             if (type_system &&
2972                 !type_system->SupportsLanguage(type_die.GetLanguage()))
2973               continue;
2974             bool try_resolving_type = false;
2975 
2976             // Don't try and resolve the DIE we are looking for with the DIE
2977             // itself!
2978             const dw_tag_t type_tag = type_die.Tag();
2979             // Make sure the tags match
2980             if (type_tag == tag) {
2981               // The tags match, lets try resolving this type
2982               try_resolving_type = true;
2983             } else {
2984               // The tags don't match, but we need to watch our for a forward
2985               // declaration for a struct and ("struct foo") ends up being a
2986               // class ("class foo { ... };") or vice versa.
2987               switch (type_tag) {
2988               case DW_TAG_class_type:
2989                 // We had a "class foo", see if we ended up with a "struct foo
2990                 // { ... };"
2991                 try_resolving_type = (tag == DW_TAG_structure_type);
2992                 break;
2993               case DW_TAG_structure_type:
2994                 // We had a "struct foo", see if we ended up with a "class foo
2995                 // { ... };"
2996                 try_resolving_type = (tag == DW_TAG_class_type);
2997                 break;
2998               default:
2999                 // Tags don't match, don't event try to resolve using this type
3000                 // whose name matches....
3001                 break;
3002               }
3003             }
3004 
3005             if (try_resolving_type) {
3006               DWARFDeclContext type_dwarf_decl_ctx;
3007               type_die.GetDWARFDeclContext(type_dwarf_decl_ctx);
3008 
3009               if (log) {
3010                 GetObjectFile()->GetModule()->LogMessage(
3011                     log,
3012                     "SymbolFileDWARF::"
3013                     "FindDefinitionTypeForDWARFDeclContext(tag=%s, "
3014                     "qualified-name='%s') trying die=0x%8.8x (%s)",
3015                     DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
3016                     dwarf_decl_ctx.GetQualifiedName(), type_die.GetOffset(),
3017                     type_dwarf_decl_ctx.GetQualifiedName());
3018               }
3019 
3020               // Make sure the decl contexts match all the way up
3021               if (dwarf_decl_ctx == type_dwarf_decl_ctx) {
3022                 Type *resolved_type = ResolveType(type_die, false);
3023                 if (resolved_type && resolved_type != DIE_IS_BEING_PARSED) {
3024                   type_sp = resolved_type->shared_from_this();
3025                   break;
3026                 }
3027               }
3028             } else {
3029               if (log) {
3030                 std::string qualified_name;
3031                 type_die.GetQualifiedName(qualified_name);
3032                 GetObjectFile()->GetModule()->LogMessage(
3033                     log,
3034                     "SymbolFileDWARF::"
3035                     "FindDefinitionTypeForDWARFDeclContext(tag=%s, "
3036                     "qualified-name='%s') ignoring die=0x%8.8x (%s)",
3037                     DW_TAG_value_to_name(dwarf_decl_ctx[0].tag),
3038                     dwarf_decl_ctx.GetQualifiedName(), type_die.GetOffset(),
3039                     qualified_name.c_str());
3040               }
3041             }
3042           } else {
3043             m_index->ReportInvalidDIERef(die_ref, type_name.GetStringRef());
3044           }
3045         }
3046       }
3047     }
3048   }
3049   return type_sp;
3050 }
3051 
3052 TypeSP SymbolFileDWARF::ParseType(const SymbolContext &sc, const DWARFDIE &die,
3053                                   bool *type_is_new_ptr) {
3054   if (!die)
3055     return {};
3056 
3057   auto type_system_or_err =
3058       GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
3059   if (auto err = type_system_or_err.takeError()) {
3060     LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
3061                    std::move(err), "Unable to parse type");
3062     return {};
3063   }
3064 
3065   DWARFASTParser *dwarf_ast = type_system_or_err->GetDWARFParser();
3066   if (!dwarf_ast)
3067     return {};
3068 
3069   TypeSP type_sp = dwarf_ast->ParseTypeFromDWARF(sc, die, type_is_new_ptr);
3070   if (type_sp) {
3071     GetTypeList().Insert(type_sp);
3072 
3073     if (die.Tag() == DW_TAG_subprogram) {
3074       std::string scope_qualified_name(GetDeclContextForUID(die.GetID())
3075                                            .GetScopeQualifiedName()
3076                                            .AsCString(""));
3077       if (scope_qualified_name.size()) {
3078         m_function_scope_qualified_name_map[scope_qualified_name].insert(
3079             die.GetID());
3080       }
3081     }
3082   }
3083 
3084   return type_sp;
3085 }
3086 
3087 size_t SymbolFileDWARF::ParseTypes(const SymbolContext &sc,
3088                                    const DWARFDIE &orig_die,
3089                                    bool parse_siblings, bool parse_children) {
3090   size_t types_added = 0;
3091   DWARFDIE die = orig_die;
3092 
3093   while (die) {
3094     const dw_tag_t tag = die.Tag();
3095     bool type_is_new = false;
3096 
3097     Tag dwarf_tag = static_cast<Tag>(tag);
3098 
3099     // TODO: Currently ParseTypeFromDWARF(...) which is called by ParseType(...)
3100     // does not handle DW_TAG_subrange_type. It is not clear if this is a bug or
3101     // not.
3102     if (isType(dwarf_tag) && tag != DW_TAG_subrange_type)
3103       ParseType(sc, die, &type_is_new);
3104 
3105     if (type_is_new)
3106       ++types_added;
3107 
3108     if (parse_children && die.HasChildren()) {
3109       if (die.Tag() == DW_TAG_subprogram) {
3110         SymbolContext child_sc(sc);
3111         child_sc.function = sc.comp_unit->FindFunctionByUID(die.GetID()).get();
3112         types_added += ParseTypes(child_sc, die.GetFirstChild(), true, true);
3113       } else
3114         types_added += ParseTypes(sc, die.GetFirstChild(), true, true);
3115     }
3116 
3117     if (parse_siblings)
3118       die = die.GetSibling();
3119     else
3120       die.Clear();
3121   }
3122   return types_added;
3123 }
3124 
3125 size_t SymbolFileDWARF::ParseBlocksRecursive(Function &func) {
3126   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
3127   CompileUnit *comp_unit = func.GetCompileUnit();
3128   lldbassert(comp_unit);
3129 
3130   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(comp_unit);
3131   if (!dwarf_cu)
3132     return 0;
3133 
3134   size_t functions_added = 0;
3135   const dw_offset_t function_die_offset = func.GetID();
3136   DWARFDIE function_die = dwarf_cu->GetDIE(function_die_offset);
3137   if (function_die) {
3138     ParseBlocksRecursive(*comp_unit, &func.GetBlock(false), function_die,
3139                          LLDB_INVALID_ADDRESS, 0);
3140   }
3141 
3142   return functions_added;
3143 }
3144 
3145 size_t SymbolFileDWARF::ParseTypes(CompileUnit &comp_unit) {
3146   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
3147   size_t types_added = 0;
3148   DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
3149   if (dwarf_cu) {
3150     DWARFDIE dwarf_cu_die = dwarf_cu->DIE();
3151     if (dwarf_cu_die && dwarf_cu_die.HasChildren()) {
3152       SymbolContext sc;
3153       sc.comp_unit = &comp_unit;
3154       types_added = ParseTypes(sc, dwarf_cu_die.GetFirstChild(), true, true);
3155     }
3156   }
3157 
3158   return types_added;
3159 }
3160 
3161 size_t SymbolFileDWARF::ParseVariablesForContext(const SymbolContext &sc) {
3162   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
3163   if (sc.comp_unit != nullptr) {
3164     DWARFDebugInfo *info = DebugInfo();
3165     if (info == nullptr)
3166       return 0;
3167 
3168     if (sc.function) {
3169       DWARFDIE function_die = GetDIE(sc.function->GetID());
3170 
3171       const dw_addr_t func_lo_pc = function_die.GetAttributeValueAsAddress(
3172           DW_AT_low_pc, LLDB_INVALID_ADDRESS);
3173       if (func_lo_pc != LLDB_INVALID_ADDRESS) {
3174         const size_t num_variables = ParseVariables(
3175             sc, function_die.GetFirstChild(), func_lo_pc, true, true);
3176 
3177         // Let all blocks know they have parse all their variables
3178         sc.function->GetBlock(false).SetDidParseVariables(true, true);
3179         return num_variables;
3180       }
3181     } else if (sc.comp_unit) {
3182       DWARFUnit *dwarf_cu = info->GetUnitAtIndex(sc.comp_unit->GetID());
3183 
3184       if (dwarf_cu == nullptr)
3185         return 0;
3186 
3187       uint32_t vars_added = 0;
3188       VariableListSP variables(sc.comp_unit->GetVariableList(false));
3189 
3190       if (variables.get() == nullptr) {
3191         variables = std::make_shared<VariableList>();
3192         sc.comp_unit->SetVariableList(variables);
3193 
3194         DIEArray die_offsets;
3195         m_index->GetGlobalVariables(dwarf_cu->GetNonSkeletonUnit(),
3196                                     die_offsets);
3197         const size_t num_matches = die_offsets.size();
3198         if (num_matches) {
3199           for (size_t i = 0; i < num_matches; ++i) {
3200             const DIERef &die_ref = die_offsets[i];
3201             DWARFDIE die = GetDIE(die_ref);
3202             if (die) {
3203               VariableSP var_sp(
3204                   ParseVariableDIE(sc, die, LLDB_INVALID_ADDRESS));
3205               if (var_sp) {
3206                 variables->AddVariableIfUnique(var_sp);
3207                 ++vars_added;
3208               }
3209             } else
3210               m_index->ReportInvalidDIERef(die_ref, "");
3211           }
3212         }
3213       }
3214       return vars_added;
3215     }
3216   }
3217   return 0;
3218 }
3219 
3220 VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
3221                                              const DWARFDIE &die,
3222                                              const lldb::addr_t func_low_pc) {
3223   if (die.GetDWARF() != this)
3224     return die.GetDWARF()->ParseVariableDIE(sc, die, func_low_pc);
3225 
3226   VariableSP var_sp;
3227   if (!die)
3228     return var_sp;
3229 
3230   var_sp = GetDIEToVariable()[die.GetDIE()];
3231   if (var_sp)
3232     return var_sp; // Already been parsed!
3233 
3234   const dw_tag_t tag = die.Tag();
3235   ModuleSP module = GetObjectFile()->GetModule();
3236 
3237   if ((tag == DW_TAG_variable) || (tag == DW_TAG_constant) ||
3238       (tag == DW_TAG_formal_parameter && sc.function)) {
3239     DWARFAttributes attributes;
3240     const size_t num_attributes = die.GetAttributes(attributes);
3241     DWARFDIE spec_die;
3242     if (num_attributes > 0) {
3243       const char *name = nullptr;
3244       const char *mangled = nullptr;
3245       Declaration decl;
3246       uint32_t i;
3247       DWARFFormValue type_die_form;
3248       DWARFExpression location;
3249       bool is_external = false;
3250       bool is_artificial = false;
3251       bool location_is_const_value_data = false;
3252       bool has_explicit_location = false;
3253       DWARFFormValue const_value;
3254       Variable::RangeList scope_ranges;
3255       // AccessType accessibility = eAccessNone;
3256 
3257       for (i = 0; i < num_attributes; ++i) {
3258         dw_attr_t attr = attributes.AttributeAtIndex(i);
3259         DWARFFormValue form_value;
3260 
3261         if (attributes.ExtractFormValueAtIndex(i, form_value)) {
3262           switch (attr) {
3263           case DW_AT_decl_file:
3264             decl.SetFile(sc.comp_unit->GetSupportFiles().GetFileSpecAtIndex(
3265                 form_value.Unsigned()));
3266             break;
3267           case DW_AT_decl_line:
3268             decl.SetLine(form_value.Unsigned());
3269             break;
3270           case DW_AT_decl_column:
3271             decl.SetColumn(form_value.Unsigned());
3272             break;
3273           case DW_AT_name:
3274             name = form_value.AsCString();
3275             break;
3276           case DW_AT_linkage_name:
3277           case DW_AT_MIPS_linkage_name:
3278             mangled = form_value.AsCString();
3279             break;
3280           case DW_AT_type:
3281             type_die_form = form_value;
3282             break;
3283           case DW_AT_external:
3284             is_external = form_value.Boolean();
3285             break;
3286           case DW_AT_const_value:
3287             // If we have already found a DW_AT_location attribute, ignore this
3288             // attribute.
3289             if (!has_explicit_location) {
3290               location_is_const_value_data = true;
3291               // The constant value will be either a block, a data value or a
3292               // string.
3293               auto debug_info_data = die.GetData();
3294               if (DWARFFormValue::IsBlockForm(form_value.Form())) {
3295                 // Retrieve the value as a block expression.
3296                 uint32_t block_offset =
3297                     form_value.BlockData() - debug_info_data.GetDataStart();
3298                 uint32_t block_length = form_value.Unsigned();
3299                 location = DWARFExpression(
3300                     module,
3301                     DataExtractor(debug_info_data, block_offset, block_length),
3302                     die.GetCU());
3303               } else if (DWARFFormValue::IsDataForm(form_value.Form())) {
3304                 // Retrieve the value as a data expression.
3305                 uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
3306                 if (auto data_length = form_value.GetFixedSize())
3307                   location = DWARFExpression(
3308                       module,
3309                       DataExtractor(debug_info_data, data_offset, *data_length),
3310                       die.GetCU());
3311                 else {
3312                   const uint8_t *data_pointer = form_value.BlockData();
3313                   if (data_pointer) {
3314                     form_value.Unsigned();
3315                   } else if (DWARFFormValue::IsDataForm(form_value.Form())) {
3316                     // we need to get the byte size of the type later after we
3317                     // create the variable
3318                     const_value = form_value;
3319                   }
3320                 }
3321               } else {
3322                 // Retrieve the value as a string expression.
3323                 if (form_value.Form() == DW_FORM_strp) {
3324                   uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
3325                   if (auto data_length = form_value.GetFixedSize())
3326                     location = DWARFExpression(module,
3327                                                DataExtractor(debug_info_data,
3328                                                              data_offset,
3329                                                              *data_length),
3330                                                die.GetCU());
3331                 } else {
3332                   const char *str = form_value.AsCString();
3333                   uint32_t string_offset =
3334                       str - (const char *)debug_info_data.GetDataStart();
3335                   uint32_t string_length = strlen(str) + 1;
3336                   location = DWARFExpression(module,
3337                                              DataExtractor(debug_info_data,
3338                                                            string_offset,
3339                                                            string_length),
3340                                              die.GetCU());
3341                 }
3342               }
3343             }
3344             break;
3345           case DW_AT_location: {
3346             location_is_const_value_data = false;
3347             has_explicit_location = true;
3348             if (DWARFFormValue::IsBlockForm(form_value.Form())) {
3349               auto data = die.GetData();
3350 
3351               uint32_t block_offset =
3352                   form_value.BlockData() - data.GetDataStart();
3353               uint32_t block_length = form_value.Unsigned();
3354               location = DWARFExpression(
3355                   module, DataExtractor(data, block_offset, block_length),
3356                   die.GetCU());
3357             } else {
3358               DataExtractor data = die.GetCU()->GetLocationData();
3359               dw_offset_t offset = form_value.Unsigned();
3360               if (form_value.Form() == DW_FORM_loclistx)
3361                 offset = die.GetCU()->GetLoclistOffset(offset).getValueOr(-1);
3362               if (data.ValidOffset(offset)) {
3363                 data = DataExtractor(data, offset, data.GetByteSize() - offset);
3364                 location = DWARFExpression(module, data, die.GetCU());
3365                 assert(func_low_pc != LLDB_INVALID_ADDRESS);
3366                 location.SetLocationListAddresses(
3367                     attributes.CompileUnitAtIndex(i)->GetBaseAddress(),
3368                     func_low_pc);
3369               }
3370             }
3371           } break;
3372           case DW_AT_specification:
3373             spec_die = form_value.Reference();
3374             break;
3375           case DW_AT_start_scope:
3376             // TODO: Implement this.
3377             break;
3378           case DW_AT_artificial:
3379             is_artificial = form_value.Boolean();
3380             break;
3381           case DW_AT_accessibility:
3382             break; // accessibility =
3383                    // DW_ACCESS_to_AccessType(form_value.Unsigned()); break;
3384           case DW_AT_declaration:
3385           case DW_AT_description:
3386           case DW_AT_endianity:
3387           case DW_AT_segment:
3388           case DW_AT_visibility:
3389           default:
3390           case DW_AT_abstract_origin:
3391           case DW_AT_sibling:
3392             break;
3393           }
3394         }
3395       }
3396 
3397       const DWARFDIE parent_context_die = GetDeclContextDIEContainingDIE(die);
3398       const dw_tag_t parent_tag = die.GetParent().Tag();
3399       bool is_static_member =
3400           (parent_tag == DW_TAG_compile_unit ||
3401            parent_tag == DW_TAG_partial_unit) &&
3402           (parent_context_die.Tag() == DW_TAG_class_type ||
3403            parent_context_die.Tag() == DW_TAG_structure_type);
3404 
3405       ValueType scope = eValueTypeInvalid;
3406 
3407       const DWARFDIE sc_parent_die = GetParentSymbolContextDIE(die);
3408       SymbolContextScope *symbol_context_scope = nullptr;
3409 
3410       bool has_explicit_mangled = mangled != nullptr;
3411       if (!mangled) {
3412         // LLDB relies on the mangled name (DW_TAG_linkage_name or
3413         // DW_AT_MIPS_linkage_name) to generate fully qualified names
3414         // of global variables with commands like "frame var j". For
3415         // example, if j were an int variable holding a value 4 and
3416         // declared in a namespace B which in turn is contained in a
3417         // namespace A, the command "frame var j" returns
3418         //   "(int) A::B::j = 4".
3419         // If the compiler does not emit a linkage name, we should be
3420         // able to generate a fully qualified name from the
3421         // declaration context.
3422         if ((parent_tag == DW_TAG_compile_unit ||
3423              parent_tag == DW_TAG_partial_unit) &&
3424             Language::LanguageIsCPlusPlus(die.GetLanguage())) {
3425           DWARFDeclContext decl_ctx;
3426 
3427           die.GetDWARFDeclContext(decl_ctx);
3428           mangled = decl_ctx.GetQualifiedNameAsConstString().GetCString();
3429         }
3430       }
3431 
3432       if (tag == DW_TAG_formal_parameter)
3433         scope = eValueTypeVariableArgument;
3434       else {
3435         // DWARF doesn't specify if a DW_TAG_variable is a local, global
3436         // or static variable, so we have to do a little digging:
3437         // 1) DW_AT_linkage_name implies static lifetime (but may be missing)
3438         // 2) An empty DW_AT_location is an (optimized-out) static lifetime var.
3439         // 3) DW_AT_location containing a DW_OP_addr implies static lifetime.
3440         // Clang likes to combine small global variables into the same symbol
3441         // with locations like: DW_OP_addr(0x1000), DW_OP_constu(2), DW_OP_plus
3442         // so we need to look through the whole expression.
3443         bool is_static_lifetime =
3444             has_explicit_mangled ||
3445             (has_explicit_location && !location.IsValid());
3446         // Check if the location has a DW_OP_addr with any address value...
3447         lldb::addr_t location_DW_OP_addr = LLDB_INVALID_ADDRESS;
3448         if (!location_is_const_value_data) {
3449           bool op_error = false;
3450           location_DW_OP_addr = location.GetLocation_DW_OP_addr(0, op_error);
3451           if (op_error) {
3452             StreamString strm;
3453             location.DumpLocationForAddress(&strm, eDescriptionLevelFull, 0, 0,
3454                                             nullptr);
3455             GetObjectFile()->GetModule()->ReportError(
3456                 "0x%8.8x: %s has an invalid location: %s", die.GetOffset(),
3457                 die.GetTagAsCString(), strm.GetData());
3458           }
3459           if (location_DW_OP_addr != LLDB_INVALID_ADDRESS)
3460             is_static_lifetime = true;
3461         }
3462         SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
3463         if (debug_map_symfile)
3464           // Set the module of the expression to the linked module
3465           // instead of the oject file so the relocated address can be
3466           // found there.
3467           location.SetModule(debug_map_symfile->GetObjectFile()->GetModule());
3468 
3469         if (is_static_lifetime) {
3470           if (is_external)
3471             scope = eValueTypeVariableGlobal;
3472           else
3473             scope = eValueTypeVariableStatic;
3474 
3475           if (debug_map_symfile) {
3476             // When leaving the DWARF in the .o files on darwin, when we have a
3477             // global variable that wasn't initialized, the .o file might not
3478             // have allocated a virtual address for the global variable. In
3479             // this case it will have created a symbol for the global variable
3480             // that is undefined/data and external and the value will be the
3481             // byte size of the variable. When we do the address map in
3482             // SymbolFileDWARFDebugMap we rely on having an address, we need to
3483             // do some magic here so we can get the correct address for our
3484             // global variable. The address for all of these entries will be
3485             // zero, and there will be an undefined symbol in this object file,
3486             // and the executable will have a matching symbol with a good
3487             // address. So here we dig up the correct address and replace it in
3488             // the location for the variable, and set the variable's symbol
3489             // context scope to be that of the main executable so the file
3490             // address will resolve correctly.
3491             bool linked_oso_file_addr = false;
3492             if (is_external && location_DW_OP_addr == 0) {
3493               // we have a possible uninitialized extern global
3494               ConstString const_name(mangled ? mangled : name);
3495               ObjectFile *debug_map_objfile =
3496                   debug_map_symfile->GetObjectFile();
3497               if (debug_map_objfile) {
3498                 Symtab *debug_map_symtab = debug_map_objfile->GetSymtab();
3499                 if (debug_map_symtab) {
3500                   Symbol *exe_symbol =
3501                       debug_map_symtab->FindFirstSymbolWithNameAndType(
3502                           const_name, eSymbolTypeData, Symtab::eDebugYes,
3503                           Symtab::eVisibilityExtern);
3504                   if (exe_symbol) {
3505                     if (exe_symbol->ValueIsAddress()) {
3506                       const addr_t exe_file_addr =
3507                           exe_symbol->GetAddressRef().GetFileAddress();
3508                       if (exe_file_addr != LLDB_INVALID_ADDRESS) {
3509                         if (location.Update_DW_OP_addr(exe_file_addr)) {
3510                           linked_oso_file_addr = true;
3511                           symbol_context_scope = exe_symbol;
3512                         }
3513                       }
3514                     }
3515                   }
3516                 }
3517               }
3518             }
3519 
3520             if (!linked_oso_file_addr) {
3521               // The DW_OP_addr is not zero, but it contains a .o file address
3522               // which needs to be linked up correctly.
3523               const lldb::addr_t exe_file_addr =
3524                   debug_map_symfile->LinkOSOFileAddress(this,
3525                                                         location_DW_OP_addr);
3526               if (exe_file_addr != LLDB_INVALID_ADDRESS) {
3527                 // Update the file address for this variable
3528                 location.Update_DW_OP_addr(exe_file_addr);
3529               } else {
3530                 // Variable didn't make it into the final executable
3531                 return var_sp;
3532               }
3533             }
3534           }
3535         } else {
3536           if (location_is_const_value_data)
3537             scope = eValueTypeVariableStatic;
3538           else {
3539             scope = eValueTypeVariableLocal;
3540             if (debug_map_symfile) {
3541               // We need to check for TLS addresses that we need to fixup
3542               if (location.ContainsThreadLocalStorage()) {
3543                 location.LinkThreadLocalStorage(
3544                     debug_map_symfile->GetObjectFile()->GetModule(),
3545                     [this, debug_map_symfile](
3546                         lldb::addr_t unlinked_file_addr) -> lldb::addr_t {
3547                       return debug_map_symfile->LinkOSOFileAddress(
3548                           this, unlinked_file_addr);
3549                     });
3550                 scope = eValueTypeVariableThreadLocal;
3551               }
3552             }
3553           }
3554         }
3555       }
3556 
3557       if (symbol_context_scope == nullptr) {
3558         switch (parent_tag) {
3559         case DW_TAG_subprogram:
3560         case DW_TAG_inlined_subroutine:
3561         case DW_TAG_lexical_block:
3562           if (sc.function) {
3563             symbol_context_scope = sc.function->GetBlock(true).FindBlockByID(
3564                 sc_parent_die.GetID());
3565             if (symbol_context_scope == nullptr)
3566               symbol_context_scope = sc.function;
3567           }
3568           break;
3569 
3570         default:
3571           symbol_context_scope = sc.comp_unit;
3572           break;
3573         }
3574       }
3575 
3576       if (symbol_context_scope) {
3577         SymbolFileTypeSP type_sp(
3578             new SymbolFileType(*this, GetUID(type_die_form.Reference())));
3579 
3580         if (const_value.Form() && type_sp && type_sp->GetType())
3581           location.UpdateValue(const_value.Unsigned(),
3582                                type_sp->GetType()->GetByteSize().getValueOr(0),
3583                                die.GetCU()->GetAddressByteSize());
3584 
3585         var_sp = std::make_shared<Variable>(
3586             die.GetID(), name, mangled, type_sp, scope, symbol_context_scope,
3587             scope_ranges, &decl, location, is_external, is_artificial,
3588             is_static_member);
3589 
3590         var_sp->SetLocationIsConstantValueData(location_is_const_value_data);
3591       } else {
3592         // Not ready to parse this variable yet. It might be a global or static
3593         // variable that is in a function scope and the function in the symbol
3594         // context wasn't filled in yet
3595         return var_sp;
3596       }
3597     }
3598     // Cache var_sp even if NULL (the variable was just a specification or was
3599     // missing vital information to be able to be displayed in the debugger
3600     // (missing location due to optimization, etc)) so we don't re-parse this
3601     // DIE over and over later...
3602     GetDIEToVariable()[die.GetDIE()] = var_sp;
3603     if (spec_die)
3604       GetDIEToVariable()[spec_die.GetDIE()] = var_sp;
3605   }
3606   return var_sp;
3607 }
3608 
3609 DWARFDIE
3610 SymbolFileDWARF::FindBlockContainingSpecification(
3611     const DIERef &func_die_ref, dw_offset_t spec_block_die_offset) {
3612   // Give the concrete function die specified by "func_die_offset", find the
3613   // concrete block whose DW_AT_specification or DW_AT_abstract_origin points
3614   // to "spec_block_die_offset"
3615   return FindBlockContainingSpecification(DebugInfo()->GetDIE(func_die_ref),
3616                                           spec_block_die_offset);
3617 }
3618 
3619 DWARFDIE
3620 SymbolFileDWARF::FindBlockContainingSpecification(
3621     const DWARFDIE &die, dw_offset_t spec_block_die_offset) {
3622   if (die) {
3623     switch (die.Tag()) {
3624     case DW_TAG_subprogram:
3625     case DW_TAG_inlined_subroutine:
3626     case DW_TAG_lexical_block: {
3627       if (die.GetReferencedDIE(DW_AT_specification).GetOffset() ==
3628           spec_block_die_offset)
3629         return die;
3630 
3631       if (die.GetReferencedDIE(DW_AT_abstract_origin).GetOffset() ==
3632           spec_block_die_offset)
3633         return die;
3634     } break;
3635     default:
3636       break;
3637     }
3638 
3639     // Give the concrete function die specified by "func_die_offset", find the
3640     // concrete block whose DW_AT_specification or DW_AT_abstract_origin points
3641     // to "spec_block_die_offset"
3642     for (DWARFDIE child_die = die.GetFirstChild(); child_die;
3643          child_die = child_die.GetSibling()) {
3644       DWARFDIE result_die =
3645           FindBlockContainingSpecification(child_die, spec_block_die_offset);
3646       if (result_die)
3647         return result_die;
3648     }
3649   }
3650 
3651   return DWARFDIE();
3652 }
3653 
3654 size_t SymbolFileDWARF::ParseVariables(const SymbolContext &sc,
3655                                        const DWARFDIE &orig_die,
3656                                        const lldb::addr_t func_low_pc,
3657                                        bool parse_siblings, bool parse_children,
3658                                        VariableList *cc_variable_list) {
3659   if (!orig_die)
3660     return 0;
3661 
3662   VariableListSP variable_list_sp;
3663 
3664   size_t vars_added = 0;
3665   DWARFDIE die = orig_die;
3666   while (die) {
3667     dw_tag_t tag = die.Tag();
3668 
3669     // Check to see if we have already parsed this variable or constant?
3670     VariableSP var_sp = GetDIEToVariable()[die.GetDIE()];
3671     if (var_sp) {
3672       if (cc_variable_list)
3673         cc_variable_list->AddVariableIfUnique(var_sp);
3674     } else {
3675       // We haven't already parsed it, lets do that now.
3676       if ((tag == DW_TAG_variable) || (tag == DW_TAG_constant) ||
3677           (tag == DW_TAG_formal_parameter && sc.function)) {
3678         if (variable_list_sp.get() == nullptr) {
3679           DWARFDIE sc_parent_die = GetParentSymbolContextDIE(orig_die);
3680           dw_tag_t parent_tag = sc_parent_die.Tag();
3681           switch (parent_tag) {
3682           case DW_TAG_compile_unit:
3683           case DW_TAG_partial_unit:
3684             if (sc.comp_unit != nullptr) {
3685               variable_list_sp = sc.comp_unit->GetVariableList(false);
3686               if (variable_list_sp.get() == nullptr) {
3687                 variable_list_sp = std::make_shared<VariableList>();
3688               }
3689             } else {
3690               GetObjectFile()->GetModule()->ReportError(
3691                   "parent 0x%8.8" PRIx64 " %s with no valid compile unit in "
3692                   "symbol context for 0x%8.8" PRIx64 " %s.\n",
3693                   sc_parent_die.GetID(), sc_parent_die.GetTagAsCString(),
3694                   orig_die.GetID(), orig_die.GetTagAsCString());
3695             }
3696             break;
3697 
3698           case DW_TAG_subprogram:
3699           case DW_TAG_inlined_subroutine:
3700           case DW_TAG_lexical_block:
3701             if (sc.function != nullptr) {
3702               // Check to see if we already have parsed the variables for the
3703               // given scope
3704 
3705               Block *block = sc.function->GetBlock(true).FindBlockByID(
3706                   sc_parent_die.GetID());
3707               if (block == nullptr) {
3708                 // This must be a specification or abstract origin with a
3709                 // concrete block counterpart in the current function. We need
3710                 // to find the concrete block so we can correctly add the
3711                 // variable to it
3712                 const DWARFDIE concrete_block_die =
3713                     FindBlockContainingSpecification(
3714                         GetDIE(sc.function->GetID()),
3715                         sc_parent_die.GetOffset());
3716                 if (concrete_block_die)
3717                   block = sc.function->GetBlock(true).FindBlockByID(
3718                       concrete_block_die.GetID());
3719               }
3720 
3721               if (block != nullptr) {
3722                 const bool can_create = false;
3723                 variable_list_sp = block->GetBlockVariableList(can_create);
3724                 if (variable_list_sp.get() == nullptr) {
3725                   variable_list_sp = std::make_shared<VariableList>();
3726                   block->SetVariableList(variable_list_sp);
3727                 }
3728               }
3729             }
3730             break;
3731 
3732           default:
3733             GetObjectFile()->GetModule()->ReportError(
3734                 "didn't find appropriate parent DIE for variable list for "
3735                 "0x%8.8" PRIx64 " %s.\n",
3736                 orig_die.GetID(), orig_die.GetTagAsCString());
3737             break;
3738           }
3739         }
3740 
3741         if (variable_list_sp) {
3742           VariableSP var_sp(ParseVariableDIE(sc, die, func_low_pc));
3743           if (var_sp) {
3744             variable_list_sp->AddVariableIfUnique(var_sp);
3745             if (cc_variable_list)
3746               cc_variable_list->AddVariableIfUnique(var_sp);
3747             ++vars_added;
3748           }
3749         }
3750       }
3751     }
3752 
3753     bool skip_children = (sc.function == nullptr && tag == DW_TAG_subprogram);
3754 
3755     if (!skip_children && parse_children && die.HasChildren()) {
3756       vars_added += ParseVariables(sc, die.GetFirstChild(), func_low_pc, true,
3757                                    true, cc_variable_list);
3758     }
3759 
3760     if (parse_siblings)
3761       die = die.GetSibling();
3762     else
3763       die.Clear();
3764   }
3765   return vars_added;
3766 }
3767 
3768 /// Collect call site parameters in a DW_TAG_call_site DIE.
3769 static CallSiteParameterArray
3770 CollectCallSiteParameters(ModuleSP module, DWARFDIE call_site_die) {
3771   CallSiteParameterArray parameters;
3772   for (DWARFDIE child = call_site_die.GetFirstChild(); child.IsValid();
3773        child = child.GetSibling()) {
3774     if (child.Tag() != DW_TAG_call_site_parameter)
3775       continue;
3776 
3777     llvm::Optional<DWARFExpression> LocationInCallee;
3778     llvm::Optional<DWARFExpression> LocationInCaller;
3779 
3780     DWARFAttributes attributes;
3781     const size_t num_attributes = child.GetAttributes(attributes);
3782 
3783     // Parse the location at index \p attr_index within this call site parameter
3784     // DIE, or return None on failure.
3785     auto parse_simple_location =
3786         [&](int attr_index) -> llvm::Optional<DWARFExpression> {
3787       DWARFFormValue form_value;
3788       if (!attributes.ExtractFormValueAtIndex(attr_index, form_value))
3789         return {};
3790       if (!DWARFFormValue::IsBlockForm(form_value.Form()))
3791         return {};
3792       auto data = child.GetData();
3793       uint32_t block_offset = form_value.BlockData() - data.GetDataStart();
3794       uint32_t block_length = form_value.Unsigned();
3795       return DWARFExpression(module,
3796                              DataExtractor(data, block_offset, block_length),
3797                              child.GetCU());
3798     };
3799 
3800     for (size_t i = 0; i < num_attributes; ++i) {
3801       dw_attr_t attr = attributes.AttributeAtIndex(i);
3802       if (attr == DW_AT_location)
3803         LocationInCallee = parse_simple_location(i);
3804       if (attr == DW_AT_call_value)
3805         LocationInCaller = parse_simple_location(i);
3806     }
3807 
3808     if (LocationInCallee && LocationInCaller) {
3809       CallSiteParameter param = {*LocationInCallee, *LocationInCaller};
3810       parameters.push_back(param);
3811     }
3812   }
3813   return parameters;
3814 }
3815 
3816 /// Collect call graph edges present in a function DIE.
3817 static std::vector<std::unique_ptr<lldb_private::CallEdge>>
3818 CollectCallEdges(ModuleSP module, DWARFDIE function_die) {
3819   // Check if the function has a supported call site-related attribute.
3820   // TODO: In the future it may be worthwhile to support call_all_source_calls.
3821   uint64_t has_call_edges =
3822       function_die.GetAttributeValueAsUnsigned(DW_AT_call_all_calls, 0);
3823   if (!has_call_edges)
3824     return {};
3825 
3826   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
3827   LLDB_LOG(log, "CollectCallEdges: Found call site info in {0}",
3828            function_die.GetPubname());
3829 
3830   // Scan the DIE for TAG_call_site entries.
3831   // TODO: A recursive scan of all blocks in the subprogram is needed in order
3832   // to be DWARF5-compliant. This may need to be done lazily to be performant.
3833   // For now, assume that all entries are nested directly under the subprogram
3834   // (this is the kind of DWARF LLVM produces) and parse them eagerly.
3835   std::vector<std::unique_ptr<CallEdge>> call_edges;
3836   for (DWARFDIE child = function_die.GetFirstChild(); child.IsValid();
3837        child = child.GetSibling()) {
3838     if (child.Tag() != DW_TAG_call_site)
3839       continue;
3840 
3841     llvm::Optional<DWARFDIE> call_origin;
3842     llvm::Optional<DWARFExpression> call_target;
3843     addr_t return_pc = LLDB_INVALID_ADDRESS;
3844 
3845     DWARFAttributes attributes;
3846     const size_t num_attributes = child.GetAttributes(attributes);
3847     for (size_t i = 0; i < num_attributes; ++i) {
3848       DWARFFormValue form_value;
3849       if (!attributes.ExtractFormValueAtIndex(i, form_value)) {
3850         LLDB_LOG(log, "CollectCallEdges: Could not extract TAG_call_site form");
3851         break;
3852       }
3853 
3854       dw_attr_t attr = attributes.AttributeAtIndex(i);
3855 
3856       // Extract DW_AT_call_origin (the call target's DIE).
3857       if (attr == DW_AT_call_origin) {
3858         call_origin = form_value.Reference();
3859         if (!call_origin->IsValid()) {
3860           LLDB_LOG(log, "CollectCallEdges: Invalid call origin in {0}",
3861                    function_die.GetPubname());
3862           break;
3863         }
3864       }
3865 
3866       // Extract DW_AT_call_return_pc (the PC the call returns to) if it's
3867       // available. It should only ever be unavailable for tail call edges, in
3868       // which case use LLDB_INVALID_ADDRESS.
3869       if (attr == DW_AT_call_return_pc)
3870         return_pc = form_value.Address();
3871 
3872       // Extract DW_AT_call_target (the location of the address of the indirect
3873       // call).
3874       if (attr == DW_AT_call_target) {
3875         if (!DWARFFormValue::IsBlockForm(form_value.Form())) {
3876           LLDB_LOG(log,
3877                    "CollectCallEdges: AT_call_target does not have block form");
3878           break;
3879         }
3880 
3881         auto data = child.GetData();
3882         uint32_t block_offset = form_value.BlockData() - data.GetDataStart();
3883         uint32_t block_length = form_value.Unsigned();
3884         call_target = DWARFExpression(
3885             module, DataExtractor(data, block_offset, block_length),
3886             child.GetCU());
3887       }
3888     }
3889     if (!call_origin && !call_target) {
3890       LLDB_LOG(log, "CollectCallEdges: call site without any call target");
3891       continue;
3892     }
3893 
3894     // Extract call site parameters.
3895     CallSiteParameterArray parameters =
3896         CollectCallSiteParameters(module, child);
3897 
3898     std::unique_ptr<CallEdge> edge;
3899     if (call_origin) {
3900       LLDB_LOG(log, "CollectCallEdges: Found call origin: {0} (retn-PC: {1:x})",
3901                call_origin->GetPubname(), return_pc);
3902       edge = std::make_unique<DirectCallEdge>(call_origin->GetMangledName(),
3903                                               return_pc, std::move(parameters));
3904     } else {
3905       if (log) {
3906         StreamString call_target_desc;
3907         call_target->GetDescription(&call_target_desc, eDescriptionLevelBrief,
3908                                     LLDB_INVALID_ADDRESS, nullptr);
3909         LLDB_LOG(log, "CollectCallEdges: Found indirect call target: {0}",
3910                  call_target_desc.GetString());
3911       }
3912       edge = std::make_unique<IndirectCallEdge>(*call_target, return_pc,
3913                                                 std::move(parameters));
3914     }
3915 
3916     if (log && parameters.size()) {
3917       for (const CallSiteParameter &param : parameters) {
3918         StreamString callee_loc_desc, caller_loc_desc;
3919         param.LocationInCallee.GetDescription(&callee_loc_desc,
3920                                               eDescriptionLevelBrief,
3921                                               LLDB_INVALID_ADDRESS, nullptr);
3922         param.LocationInCaller.GetDescription(&caller_loc_desc,
3923                                               eDescriptionLevelBrief,
3924                                               LLDB_INVALID_ADDRESS, nullptr);
3925         LLDB_LOG(log, "CollectCallEdges: \tparam: {0} => {1}",
3926                  callee_loc_desc.GetString(), caller_loc_desc.GetString());
3927       }
3928     }
3929 
3930     call_edges.push_back(std::move(edge));
3931   }
3932   return call_edges;
3933 }
3934 
3935 std::vector<std::unique_ptr<lldb_private::CallEdge>>
3936 SymbolFileDWARF::ParseCallEdgesInFunction(UserID func_id) {
3937   DWARFDIE func_die = GetDIE(func_id.GetID());
3938   if (func_die.IsValid())
3939     return CollectCallEdges(GetObjectFile()->GetModule(), func_die);
3940   return {};
3941 }
3942 
3943 // PluginInterface protocol
3944 ConstString SymbolFileDWARF::GetPluginName() { return GetPluginNameStatic(); }
3945 
3946 uint32_t SymbolFileDWARF::GetPluginVersion() { return 1; }
3947 
3948 void SymbolFileDWARF::Dump(lldb_private::Stream &s) {
3949   SymbolFile::Dump(s);
3950   m_index->Dump(s);
3951 }
3952 
3953 void SymbolFileDWARF::DumpClangAST(Stream &s) {
3954   auto ts_or_err = GetTypeSystemForLanguage(eLanguageTypeC_plus_plus);
3955   if (!ts_or_err)
3956     return;
3957   ClangASTContext *clang =
3958       llvm::dyn_cast_or_null<ClangASTContext>(&ts_or_err.get());
3959   if (!clang)
3960     return;
3961   clang->Dump(s);
3962 }
3963 
3964 SymbolFileDWARFDebugMap *SymbolFileDWARF::GetDebugMapSymfile() {
3965   if (m_debug_map_symfile == nullptr && !m_debug_map_module_wp.expired()) {
3966     lldb::ModuleSP module_sp(m_debug_map_module_wp.lock());
3967     if (module_sp) {
3968       m_debug_map_symfile =
3969           (SymbolFileDWARFDebugMap *)module_sp->GetSymbolFile();
3970     }
3971   }
3972   return m_debug_map_symfile;
3973 }
3974 
3975 SymbolFileDWARFDwp *SymbolFileDWARF::GetDwpSymbolFile() {
3976   llvm::call_once(m_dwp_symfile_once_flag, [this]() {
3977     ModuleSpec module_spec;
3978     module_spec.GetFileSpec() = m_objfile_sp->GetFileSpec();
3979     module_spec.GetSymbolFileSpec() =
3980         FileSpec(m_objfile_sp->GetFileSpec().GetPath() + ".dwp");
3981 
3982     FileSpecList search_paths = Target::GetDefaultDebugFileSearchPaths();
3983     FileSpec dwp_filespec =
3984         Symbols::LocateExecutableSymbolFile(module_spec, search_paths);
3985     if (FileSystem::Instance().Exists(dwp_filespec)) {
3986       m_dwp_symfile = SymbolFileDWARFDwp::Create(GetObjectFile()->GetModule(),
3987                                                  dwp_filespec);
3988     }
3989   });
3990   return m_dwp_symfile.get();
3991 }
3992