1 //===-- ManualDWARFIndex.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 "Plugins/SymbolFile/DWARF/ManualDWARFIndex.h"
10 #include "Plugins/Language/ObjC/ObjCLanguage.h"
11 #include "Plugins/SymbolFile/DWARF/DWARFDebugInfo.h"
12 #include "Plugins/SymbolFile/DWARF/DWARFDeclContext.h"
13 #include "Plugins/SymbolFile/DWARF/LogChannelDWARF.h"
14 #include "Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h"
15 #include "lldb/Core/Module.h"
16 #include "lldb/Host/TaskPool.h"
17 #include "lldb/Symbol/ObjectFile.h"
18 #include "lldb/Utility/Stream.h"
19 #include "lldb/Utility/Timer.h"
20 
21 using namespace lldb_private;
22 using namespace lldb;
23 
24 void ManualDWARFIndex::Index() {
25   if (!m_debug_info)
26     return;
27 
28   DWARFDebugInfo &debug_info = *m_debug_info;
29   m_debug_info = nullptr;
30 
31   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
32   Timer scoped_timer(func_cat, "%p", static_cast<void *>(&debug_info));
33 
34   std::vector<DWARFUnit *> units_to_index;
35   units_to_index.reserve(debug_info.GetNumCompileUnits());
36   for (size_t U = 0; U < debug_info.GetNumCompileUnits(); ++U) {
37     DWARFUnit *unit = debug_info.GetCompileUnitAtIndex(U);
38     if (unit && m_units_to_avoid.count(unit->GetOffset()) == 0)
39       units_to_index.push_back(unit);
40   }
41   if (units_to_index.empty())
42     return;
43 
44   std::vector<IndexSet> sets(units_to_index.size());
45 
46   // Keep memory down by clearing DIEs for any compile units if indexing
47   // caused us to load the compile unit's DIEs.
48   std::vector<llvm::Optional<DWARFUnit::ScopedExtractDIEs>> clear_cu_dies(
49       units_to_index.size());
50   auto parser_fn = [&](size_t cu_idx) {
51     IndexUnit(*units_to_index[cu_idx], sets[cu_idx]);
52   };
53 
54   auto extract_fn = [&units_to_index, &clear_cu_dies](size_t cu_idx) {
55     clear_cu_dies[cu_idx] = units_to_index[cu_idx]->ExtractDIEsScoped();
56   };
57 
58   // Create a task runner that extracts dies for each DWARF compile unit in a
59   // separate thread
60   // First figure out which compile units didn't have their DIEs already
61   // parsed and remember this.  If no DIEs were parsed prior to this index
62   // function call, we are going to want to clear the CU dies after we are
63   // done indexing to make sure we don't pull in all DWARF dies, but we need
64   // to wait until all compile units have been indexed in case a DIE in one
65   // compile unit refers to another and the indexes accesses those DIEs.
66   TaskMapOverInt(0, units_to_index.size(), extract_fn);
67 
68   // Now create a task runner that can index each DWARF compile unit in a
69   // separate thread so we can index quickly.
70 
71   TaskMapOverInt(0, units_to_index.size(), parser_fn);
72 
73   auto finalize_fn = [this, &sets](NameToDIE(IndexSet::*index)) {
74     NameToDIE &result = m_set.*index;
75     for (auto &set : sets)
76       result.Append(set.*index);
77     result.Finalize();
78   };
79 
80   TaskPool::RunTasks([&]() { finalize_fn(&IndexSet::function_basenames); },
81                      [&]() { finalize_fn(&IndexSet::function_fullnames); },
82                      [&]() { finalize_fn(&IndexSet::function_methods); },
83                      [&]() { finalize_fn(&IndexSet::function_selectors); },
84                      [&]() { finalize_fn(&IndexSet::objc_class_selectors); },
85                      [&]() { finalize_fn(&IndexSet::globals); },
86                      [&]() { finalize_fn(&IndexSet::types); },
87                      [&]() { finalize_fn(&IndexSet::namespaces); });
88 }
89 
90 void ManualDWARFIndex::IndexUnit(DWARFUnit &unit, IndexSet &set) {
91   assert(!unit.GetSymbolFileDWARF()->GetBaseCompileUnit() &&
92       "DWARFUnit associated with .dwo or .dwp should not be indexed directly");
93 
94   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_LOOKUPS);
95 
96   if (log) {
97     m_module.LogMessage(
98         log, "ManualDWARFIndex::IndexUnit for compile unit at .debug_info[0x%8.8x]",
99         unit.GetOffset());
100   }
101 
102   const LanguageType cu_language = unit.GetLanguageType();
103   DWARFFormValue::FixedFormSizes fixed_form_sizes = unit.GetFixedFormSizes();
104 
105   IndexUnitImpl(unit, cu_language, fixed_form_sizes, unit.GetOffset(), set);
106 
107   SymbolFileDWARFDwo *dwo_symbol_file = unit.GetDwoSymbolFile();
108   if (dwo_symbol_file && dwo_symbol_file->GetCompileUnit()) {
109     IndexUnitImpl(*dwo_symbol_file->GetCompileUnit(), cu_language,
110                   fixed_form_sizes, unit.GetOffset(), set);
111   }
112 }
113 
114 void ManualDWARFIndex::IndexUnitImpl(
115     DWARFUnit &unit, const LanguageType cu_language,
116     const DWARFFormValue::FixedFormSizes &fixed_form_sizes,
117     const dw_offset_t cu_offset, IndexSet &set) {
118   for (const DWARFDebugInfoEntry &die : unit.dies()) {
119     const dw_tag_t tag = die.Tag();
120 
121     switch (tag) {
122     case DW_TAG_array_type:
123     case DW_TAG_base_type:
124     case DW_TAG_class_type:
125     case DW_TAG_constant:
126     case DW_TAG_enumeration_type:
127     case DW_TAG_inlined_subroutine:
128     case DW_TAG_namespace:
129     case DW_TAG_string_type:
130     case DW_TAG_structure_type:
131     case DW_TAG_subprogram:
132     case DW_TAG_subroutine_type:
133     case DW_TAG_typedef:
134     case DW_TAG_union_type:
135     case DW_TAG_unspecified_type:
136     case DW_TAG_variable:
137       break;
138 
139     default:
140       continue;
141     }
142 
143     DWARFAttributes attributes;
144     const char *name = NULL;
145     const char *mangled_cstr = NULL;
146     bool is_declaration = false;
147     // bool is_artificial = false;
148     bool has_address = false;
149     bool has_location_or_const_value = false;
150     bool is_global_or_static_variable = false;
151 
152     DWARFFormValue specification_die_form;
153     const size_t num_attributes =
154         die.GetAttributes(&unit, fixed_form_sizes, attributes);
155     if (num_attributes > 0) {
156       for (uint32_t i = 0; i < num_attributes; ++i) {
157         dw_attr_t attr = attributes.AttributeAtIndex(i);
158         DWARFFormValue form_value;
159         switch (attr) {
160         case DW_AT_name:
161           if (attributes.ExtractFormValueAtIndex(i, form_value))
162             name = form_value.AsCString();
163           break;
164 
165         case DW_AT_declaration:
166           if (attributes.ExtractFormValueAtIndex(i, form_value))
167             is_declaration = form_value.Unsigned() != 0;
168           break;
169 
170         //                case DW_AT_artificial:
171         //                    if (attributes.ExtractFormValueAtIndex(i,
172         //                    form_value))
173         //                        is_artificial = form_value.Unsigned() != 0;
174         //                    break;
175 
176         case DW_AT_MIPS_linkage_name:
177         case DW_AT_linkage_name:
178           if (attributes.ExtractFormValueAtIndex(i, form_value))
179             mangled_cstr = form_value.AsCString();
180           break;
181 
182         case DW_AT_low_pc:
183         case DW_AT_high_pc:
184         case DW_AT_ranges:
185           has_address = true;
186           break;
187 
188         case DW_AT_entry_pc:
189           has_address = true;
190           break;
191 
192         case DW_AT_location:
193         case DW_AT_const_value:
194           has_location_or_const_value = true;
195           if (tag == DW_TAG_variable) {
196             const DWARFDebugInfoEntry *parent_die = die.GetParent();
197             while (parent_die != NULL) {
198               switch (parent_die->Tag()) {
199               case DW_TAG_subprogram:
200               case DW_TAG_lexical_block:
201               case DW_TAG_inlined_subroutine:
202                 // Even if this is a function level static, we don't add it. We
203                 // could theoretically add these if we wanted to by
204                 // introspecting into the DW_AT_location and seeing if the
205                 // location describes a hard coded address, but we don't want
206                 // the performance penalty of that right now.
207                 is_global_or_static_variable = false;
208                 // if (attributes.ExtractFormValueAtIndex(dwarf, i,
209                 //                                        form_value)) {
210                 //   // If we have valid block data, then we have location
211                 //   // expression bytesthat are fixed (not a location list).
212                 //   const uint8_t *block_data = form_value.BlockData();
213                 //   if (block_data) {
214                 //     uint32_t block_length = form_value.Unsigned();
215                 //     if (block_length == 1 +
216                 //     attributes.CompileUnitAtIndex(i)->GetAddressByteSize()) {
217                 //       if (block_data[0] == DW_OP_addr)
218                 //         add_die = true;
219                 //     }
220                 //   }
221                 // }
222                 parent_die = NULL; // Terminate the while loop.
223                 break;
224 
225               case DW_TAG_compile_unit:
226               case DW_TAG_partial_unit:
227                 is_global_or_static_variable = true;
228                 parent_die = NULL; // Terminate the while loop.
229                 break;
230 
231               default:
232                 parent_die =
233                     parent_die->GetParent(); // Keep going in the while loop.
234                 break;
235               }
236             }
237           }
238           break;
239 
240         case DW_AT_specification:
241           if (attributes.ExtractFormValueAtIndex(i, form_value))
242             specification_die_form = form_value;
243           break;
244         }
245       }
246     }
247 
248     switch (tag) {
249     case DW_TAG_inlined_subroutine:
250     case DW_TAG_subprogram:
251       if (has_address) {
252         if (name) {
253           ObjCLanguage::MethodName objc_method(name, true);
254           if (objc_method.IsValid(true)) {
255             ConstString objc_class_name_with_category(
256                 objc_method.GetClassNameWithCategory());
257             ConstString objc_selector_name(objc_method.GetSelector());
258             ConstString objc_fullname_no_category_name(
259                 objc_method.GetFullNameWithoutCategory(true));
260             ConstString objc_class_name_no_category(objc_method.GetClassName());
261             set.function_fullnames.Insert(ConstString(name),
262                                           DIERef(cu_offset, die.GetOffset()));
263             if (objc_class_name_with_category)
264               set.objc_class_selectors.Insert(
265                   objc_class_name_with_category,
266                   DIERef(cu_offset, die.GetOffset()));
267             if (objc_class_name_no_category &&
268                 objc_class_name_no_category != objc_class_name_with_category)
269               set.objc_class_selectors.Insert(
270                   objc_class_name_no_category,
271                   DIERef(cu_offset, die.GetOffset()));
272             if (objc_selector_name)
273               set.function_selectors.Insert(objc_selector_name,
274                                             DIERef(cu_offset, die.GetOffset()));
275             if (objc_fullname_no_category_name)
276               set.function_fullnames.Insert(objc_fullname_no_category_name,
277                                             DIERef(cu_offset, die.GetOffset()));
278           }
279           // If we have a mangled name, then the DW_AT_name attribute is
280           // usually the method name without the class or any parameters
281           bool is_method = DWARFDIE(&unit, &die).IsMethod();
282 
283           if (is_method)
284             set.function_methods.Insert(ConstString(name),
285                                         DIERef(cu_offset, die.GetOffset()));
286           else
287             set.function_basenames.Insert(ConstString(name),
288                                           DIERef(cu_offset, die.GetOffset()));
289 
290           if (!is_method && !mangled_cstr && !objc_method.IsValid(true))
291             set.function_fullnames.Insert(ConstString(name),
292                                           DIERef(cu_offset, die.GetOffset()));
293         }
294         if (mangled_cstr) {
295           // Make sure our mangled name isn't the same string table entry as
296           // our name. If it starts with '_', then it is ok, else compare the
297           // string to make sure it isn't the same and we don't end up with
298           // duplicate entries
299           if (name && name != mangled_cstr &&
300               ((mangled_cstr[0] == '_') ||
301                (::strcmp(name, mangled_cstr) != 0))) {
302             set.function_fullnames.Insert(ConstString(mangled_cstr),
303                                           DIERef(cu_offset, die.GetOffset()));
304           }
305         }
306       }
307       break;
308 
309     case DW_TAG_array_type:
310     case DW_TAG_base_type:
311     case DW_TAG_class_type:
312     case DW_TAG_constant:
313     case DW_TAG_enumeration_type:
314     case DW_TAG_string_type:
315     case DW_TAG_structure_type:
316     case DW_TAG_subroutine_type:
317     case DW_TAG_typedef:
318     case DW_TAG_union_type:
319     case DW_TAG_unspecified_type:
320       if (name && !is_declaration)
321         set.types.Insert(ConstString(name), DIERef(cu_offset, die.GetOffset()));
322       if (mangled_cstr && !is_declaration)
323         set.types.Insert(ConstString(mangled_cstr),
324                          DIERef(cu_offset, die.GetOffset()));
325       break;
326 
327     case DW_TAG_namespace:
328       if (name)
329         set.namespaces.Insert(ConstString(name),
330                               DIERef(cu_offset, die.GetOffset()));
331       break;
332 
333     case DW_TAG_variable:
334       if (name && has_location_or_const_value && is_global_or_static_variable) {
335         set.globals.Insert(ConstString(name),
336                            DIERef(cu_offset, die.GetOffset()));
337         // Be sure to include variables by their mangled and demangled names if
338         // they have any since a variable can have a basename "i", a mangled
339         // named "_ZN12_GLOBAL__N_11iE" and a demangled mangled name
340         // "(anonymous namespace)::i"...
341 
342         // Make sure our mangled name isn't the same string table entry as our
343         // name. If it starts with '_', then it is ok, else compare the string
344         // to make sure it isn't the same and we don't end up with duplicate
345         // entries
346         if (mangled_cstr && name != mangled_cstr &&
347             ((mangled_cstr[0] == '_') || (::strcmp(name, mangled_cstr) != 0))) {
348           set.globals.Insert(ConstString(mangled_cstr),
349                              DIERef(cu_offset, die.GetOffset()));
350         }
351       }
352       break;
353 
354     default:
355       continue;
356     }
357   }
358 }
359 
360 void ManualDWARFIndex::GetGlobalVariables(ConstString basename, DIEArray &offsets) {
361   Index();
362   m_set.globals.Find(basename, offsets);
363 }
364 
365 void ManualDWARFIndex::GetGlobalVariables(const RegularExpression &regex,
366                                           DIEArray &offsets) {
367   Index();
368   m_set.globals.Find(regex, offsets);
369 }
370 
371 void ManualDWARFIndex::GetGlobalVariables(const DWARFUnit &cu,
372                                           DIEArray &offsets) {
373   Index();
374   m_set.globals.FindAllEntriesForCompileUnit(cu.GetOffset(), offsets);
375 }
376 
377 void ManualDWARFIndex::GetObjCMethods(ConstString class_name,
378                                       DIEArray &offsets) {
379   Index();
380   m_set.objc_class_selectors.Find(class_name, offsets);
381 }
382 
383 void ManualDWARFIndex::GetCompleteObjCClass(ConstString class_name,
384                                             bool must_be_implementation,
385                                             DIEArray &offsets) {
386   Index();
387   m_set.types.Find(class_name, offsets);
388 }
389 
390 void ManualDWARFIndex::GetTypes(ConstString name, DIEArray &offsets) {
391   Index();
392   m_set.types.Find(name, offsets);
393 }
394 
395 void ManualDWARFIndex::GetTypes(const DWARFDeclContext &context,
396                                 DIEArray &offsets) {
397   Index();
398   m_set.types.Find(ConstString(context[0].name), offsets);
399 }
400 
401 void ManualDWARFIndex::GetNamespaces(ConstString name, DIEArray &offsets) {
402   Index();
403   m_set.namespaces.Find(name, offsets);
404 }
405 
406 void ManualDWARFIndex::GetFunctions(ConstString name, DWARFDebugInfo &info,
407                                     const CompilerDeclContext &parent_decl_ctx,
408                                     uint32_t name_type_mask,
409                                     std::vector<DWARFDIE> &dies) {
410   Index();
411 
412   if (name_type_mask & eFunctionNameTypeFull) {
413     DIEArray offsets;
414     m_set.function_basenames.Find(name, offsets);
415     m_set.function_methods.Find(name, offsets);
416     m_set.function_fullnames.Find(name, offsets);
417     for (const DIERef &die_ref: offsets) {
418       DWARFDIE die = info.GetDIE(die_ref);
419       if (!die)
420         continue;
421       if (SymbolFileDWARF::DIEInDeclContext(&parent_decl_ctx, die))
422         dies.push_back(die);
423     }
424   }
425   if (name_type_mask & eFunctionNameTypeBase) {
426     DIEArray offsets;
427     m_set.function_basenames.Find(name, offsets);
428     for (const DIERef &die_ref: offsets) {
429       DWARFDIE die = info.GetDIE(die_ref);
430       if (!die)
431         continue;
432       if (SymbolFileDWARF::DIEInDeclContext(&parent_decl_ctx, die))
433         dies.push_back(die);
434     }
435     offsets.clear();
436   }
437 
438   if (name_type_mask & eFunctionNameTypeMethod && !parent_decl_ctx.IsValid()) {
439     DIEArray offsets;
440     m_set.function_methods.Find(name, offsets);
441     for (const DIERef &die_ref: offsets) {
442       if (DWARFDIE die = info.GetDIE(die_ref))
443         dies.push_back(die);
444     }
445   }
446 
447   if (name_type_mask & eFunctionNameTypeSelector &&
448       !parent_decl_ctx.IsValid()) {
449     DIEArray offsets;
450     m_set.function_selectors.Find(name, offsets);
451     for (const DIERef &die_ref: offsets) {
452       if (DWARFDIE die = info.GetDIE(die_ref))
453         dies.push_back(die);
454     }
455   }
456 }
457 
458 void ManualDWARFIndex::GetFunctions(const RegularExpression &regex,
459                                     DIEArray &offsets) {
460   Index();
461 
462   m_set.function_basenames.Find(regex, offsets);
463   m_set.function_fullnames.Find(regex, offsets);
464 }
465 
466 void ManualDWARFIndex::Dump(Stream &s) {
467   s.Format("Manual DWARF index for ({0}) '{1:F}':",
468            m_module.GetArchitecture().GetArchitectureName(),
469            m_module.GetObjectFile()->GetFileSpec());
470   s.Printf("\nFunction basenames:\n");
471   m_set.function_basenames.Dump(&s);
472   s.Printf("\nFunction fullnames:\n");
473   m_set.function_fullnames.Dump(&s);
474   s.Printf("\nFunction methods:\n");
475   m_set.function_methods.Dump(&s);
476   s.Printf("\nFunction selectors:\n");
477   m_set.function_selectors.Dump(&s);
478   s.Printf("\nObjective-C class selectors:\n");
479   m_set.objc_class_selectors.Dump(&s);
480   s.Printf("\nGlobals and statics:\n");
481   m_set.globals.Dump(&s);
482   s.Printf("\nTypes:\n");
483   m_set.types.Dump(&s);
484   s.Printf("\nNamespaces:\n");
485   m_set.namespaces.Dump(&s);
486 }
487