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