1//===-- Symtab.cpp --------------------------------------------------------===//
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 <map>
10#include <set>
11
12#include "lldb/Core/DataFileCache.h"
13#include "lldb/Core/Module.h"
14#include "lldb/Core/RichManglingContext.h"
15#include "lldb/Core/Section.h"
16#include "lldb/Symbol/ObjectFile.h"
17#include "lldb/Symbol/Symbol.h"
18#include "lldb/Symbol/SymbolContext.h"
19#include "lldb/Symbol/Symtab.h"
20#include "lldb/Target/Language.h"
21#include "lldb/Utility/DataEncoder.h"
22#include "lldb/Utility/Endian.h"
23#include "lldb/Utility/RegularExpression.h"
24#include "lldb/Utility/Stream.h"
25#include "lldb/Utility/Timer.h"
26
27#include "llvm/ADT/ArrayRef.h"
28#include "llvm/ADT/StringRef.h"
29#include "llvm/Support/DJB.h"
30
31using namespace lldb;
32using namespace lldb_private;
33
34Symtab::Symtab(ObjectFile *objfile)
35 : m_objfile(objfile), m_symbols(), m_file_addr_to_index(*this),
36 m_name_to_symbol_indices(), m_mutex(),
37 m_file_addr_to_index_computed(false), m_name_indexes_computed(false),
38 m_loaded_from_cache(false), m_saved_to_cache(false) {
39 m_name_to_symbol_indices.emplace(args: std::make_pair(
40 x: lldb::eFunctionNameTypeNone, y: UniqueCStringMap<uint32_t>()));
41 m_name_to_symbol_indices.emplace(args: std::make_pair(
42 x: lldb::eFunctionNameTypeBase, y: UniqueCStringMap<uint32_t>()));
43 m_name_to_symbol_indices.emplace(args: std::make_pair(
44 x: lldb::eFunctionNameTypeMethod, y: UniqueCStringMap<uint32_t>()));
45 m_name_to_symbol_indices.emplace(args: std::make_pair(
46 x: lldb::eFunctionNameTypeSelector, y: UniqueCStringMap<uint32_t>()));
47}
48
49Symtab::~Symtab() = default;
50
51void Symtab::Reserve(size_t count) {
52 // Clients should grab the mutex from this symbol table and lock it manually
53 // when calling this function to avoid performance issues.
54 m_symbols.reserve(n: count);
55}
56
57Symbol *Symtab::Resize(size_t count) {
58 // Clients should grab the mutex from this symbol table and lock it manually
59 // when calling this function to avoid performance issues.
60 m_symbols.resize(new_size: count);
61 return m_symbols.empty() ? nullptr : &m_symbols[0];
62}
63
64uint32_t Symtab::AddSymbol(const Symbol &symbol) {
65 // Clients should grab the mutex from this symbol table and lock it manually
66 // when calling this function to avoid performance issues.
67 uint32_t symbol_idx = m_symbols.size();
68 auto &name_to_index = GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeNone);
69 name_to_index.Clear();
70 m_file_addr_to_index.Clear();
71 m_symbols.push_back(x: symbol);
72 m_file_addr_to_index_computed = false;
73 m_name_indexes_computed = false;
74 return symbol_idx;
75}
76
77size_t Symtab::GetNumSymbols() const {
78 std::lock_guard<std::recursive_mutex> guard(m_mutex);
79 return m_symbols.size();
80}
81
82void Symtab::SectionFileAddressesChanged() {
83 m_file_addr_to_index.Clear();
84 m_file_addr_to_index_computed = false;
85}
86
87void Symtab::Dump(Stream *s, Target *target, SortOrder sort_order,
88 Mangled::NamePreference name_preference) {
89 std::lock_guard<std::recursive_mutex> guard(m_mutex);
90
91 // s->Printf("%.*p: ", (int)sizeof(void*) * 2, this);
92 s->Indent();
93 const FileSpec &file_spec = m_objfile->GetFileSpec();
94 const char *object_name = nullptr;
95 if (m_objfile->GetModule())
96 object_name = m_objfile->GetModule()->GetObjectName().GetCString();
97
98 if (file_spec)
99 s->Printf(format: "Symtab, file = %s%s%s%s, num_symbols = %" PRIu64,
100 file_spec.GetPath().c_str(), object_name ? "(" : "",
101 object_name ? object_name : "", object_name ? ")" : "",
102 (uint64_t)m_symbols.size());
103 else
104 s->Printf(format: "Symtab, num_symbols = %" PRIu64 "", (uint64_t)m_symbols.size());
105
106 if (!m_symbols.empty()) {
107 switch (sort_order) {
108 case eSortOrderNone: {
109 s->PutCString(cstr: ":\n");
110 DumpSymbolHeader(s);
111 const_iterator begin = m_symbols.begin();
112 const_iterator end = m_symbols.end();
113 for (const_iterator pos = m_symbols.begin(); pos != end; ++pos) {
114 s->Indent();
115 pos->Dump(s, target, index: std::distance(first: begin, last: pos), name_preference);
116 }
117 }
118 break;
119
120 case eSortOrderByName: {
121 // Although we maintain a lookup by exact name map, the table isn't
122 // sorted by name. So we must make the ordered symbol list up ourselves.
123 s->PutCString(cstr: " (sorted by name):\n");
124 DumpSymbolHeader(s);
125
126 std::multimap<llvm::StringRef, const Symbol *> name_map;
127 for (const_iterator pos = m_symbols.begin(), end = m_symbols.end();
128 pos != end; ++pos) {
129 const char *name = pos->GetName().AsCString();
130 if (name && name[0])
131 name_map.insert(x: std::make_pair(x&: name, y: &(*pos)));
132 }
133
134 for (const auto &name_to_symbol : name_map) {
135 const Symbol *symbol = name_to_symbol.second;
136 s->Indent();
137 symbol->Dump(s, target, index: symbol - &m_symbols[0], name_preference);
138 }
139 } break;
140
141 case eSortOrderByAddress:
142 s->PutCString(cstr: " (sorted by address):\n");
143 DumpSymbolHeader(s);
144 if (!m_file_addr_to_index_computed)
145 InitAddressIndexes();
146 const size_t num_entries = m_file_addr_to_index.GetSize();
147 for (size_t i = 0; i < num_entries; ++i) {
148 s->Indent();
149 const uint32_t symbol_idx = m_file_addr_to_index.GetEntryRef(i).data;
150 m_symbols[symbol_idx].Dump(s, target, index: symbol_idx, name_preference);
151 }
152 break;
153 }
154 } else {
155 s->PutCString(cstr: "\n");
156 }
157}
158
159void Symtab::Dump(Stream *s, Target *target, std::vector<uint32_t> &indexes,
160 Mangled::NamePreference name_preference) const {
161 std::lock_guard<std::recursive_mutex> guard(m_mutex);
162
163 const size_t num_symbols = GetNumSymbols();
164 // s->Printf("%.*p: ", (int)sizeof(void*) * 2, this);
165 s->Indent();
166 s->Printf(format: "Symtab %" PRIu64 " symbol indexes (%" PRIu64 " symbols total):\n",
167 (uint64_t)indexes.size(), (uint64_t)m_symbols.size());
168 s->IndentMore();
169
170 if (!indexes.empty()) {
171 std::vector<uint32_t>::const_iterator pos;
172 std::vector<uint32_t>::const_iterator end = indexes.end();
173 DumpSymbolHeader(s);
174 for (pos = indexes.begin(); pos != end; ++pos) {
175 size_t idx = *pos;
176 if (idx < num_symbols) {
177 s->Indent();
178 m_symbols[idx].Dump(s, target, index: idx, name_preference);
179 }
180 }
181 }
182 s->IndentLess();
183}
184
185void Symtab::DumpSymbolHeader(Stream *s) {
186 s->Indent(s: " Debug symbol\n");
187 s->Indent(s: " |Synthetic symbol\n");
188 s->Indent(s: " ||Externally Visible\n");
189 s->Indent(s: " |||\n");
190 s->Indent(s: "Index UserID DSX Type File Address/Value Load "
191 "Address Size Flags Name\n");
192 s->Indent(s: "------- ------ --- --------------- ------------------ "
193 "------------------ ------------------ ---------- "
194 "----------------------------------\n");
195}
196
197static int CompareSymbolID(const void *key, const void *p) {
198 const user_id_t match_uid = *(const user_id_t *)key;
199 const user_id_t symbol_uid = ((const Symbol *)p)->GetID();
200 if (match_uid < symbol_uid)
201 return -1;
202 if (match_uid > symbol_uid)
203 return 1;
204 return 0;
205}
206
207Symbol *Symtab::FindSymbolByID(lldb::user_id_t symbol_uid) const {
208 std::lock_guard<std::recursive_mutex> guard(m_mutex);
209
210 Symbol *symbol =
211 (Symbol *)::bsearch(key: &symbol_uid, base: &m_symbols[0], nmemb: m_symbols.size(),
212 size: sizeof(m_symbols[0]), compar: CompareSymbolID);
213 return symbol;
214}
215
216Symbol *Symtab::SymbolAtIndex(size_t idx) {
217 // Clients should grab the mutex from this symbol table and lock it manually
218 // when calling this function to avoid performance issues.
219 if (idx < m_symbols.size())
220 return &m_symbols[idx];
221 return nullptr;
222}
223
224const Symbol *Symtab::SymbolAtIndex(size_t idx) const {
225 // Clients should grab the mutex from this symbol table and lock it manually
226 // when calling this function to avoid performance issues.
227 if (idx < m_symbols.size())
228 return &m_symbols[idx];
229 return nullptr;
230}
231
232static bool lldb_skip_name(llvm::StringRef mangled,
233 Mangled::ManglingScheme scheme) {
234 switch (scheme) {
235 case Mangled::eManglingSchemeItanium: {
236 if (mangled.size() < 3 || !mangled.starts_with(Prefix: "_Z"))
237 return true;
238
239 // Avoid the following types of symbols in the index.
240 switch (mangled[2]) {
241 case 'G': // guard variables
242 case 'T': // virtual tables, VTT structures, typeinfo structures + names
243 case 'Z': // named local entities (if we eventually handle
244 // eSymbolTypeData, we will want this back)
245 return true;
246
247 default:
248 break;
249 }
250
251 // Include this name in the index.
252 return false;
253 }
254
255 // No filters for this scheme yet. Include all names in indexing.
256 case Mangled::eManglingSchemeMSVC:
257 case Mangled::eManglingSchemeRustV0:
258 case Mangled::eManglingSchemeD:
259 case Mangled::eManglingSchemeSwift:
260 return false;
261
262 // Don't try and demangle things we can't categorize.
263 case Mangled::eManglingSchemeNone:
264 return true;
265 }
266 llvm_unreachable("unknown scheme!");
267}
268
269void Symtab::InitNameIndexes() {
270 // Protected function, no need to lock mutex...
271 if (!m_name_indexes_computed) {
272 m_name_indexes_computed = true;
273 ElapsedTime elapsed(m_objfile->GetModule()->GetSymtabIndexTime());
274 LLDB_SCOPED_TIMER();
275
276 // Collect all loaded language plugins.
277 std::vector<Language *> languages;
278 Language::ForEach(callback: [&languages](Language *l) {
279 languages.push_back(x: l);
280 return true;
281 });
282
283 auto &name_to_index = GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeNone);
284 auto &basename_to_index =
285 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeBase);
286 auto &method_to_index =
287 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeMethod);
288 auto &selector_to_index =
289 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeSelector);
290 // Create the name index vector to be able to quickly search by name
291 const size_t num_symbols = m_symbols.size();
292 name_to_index.Reserve(n: num_symbols);
293
294 // The "const char *" in "class_contexts" and backlog::value_type::second
295 // must come from a ConstString::GetCString()
296 std::set<const char *> class_contexts;
297 std::vector<std::pair<NameToIndexMap::Entry, const char *>> backlog;
298 backlog.reserve(n: num_symbols / 2);
299
300 // Instantiation of the demangler is expensive, so better use a single one
301 // for all entries during batch processing.
302 RichManglingContext rmc;
303 for (uint32_t value = 0; value < num_symbols; ++value) {
304 Symbol *symbol = &m_symbols[value];
305
306 // Don't let trampolines get into the lookup by name map If we ever need
307 // the trampoline symbols to be searchable by name we can remove this and
308 // then possibly add a new bool to any of the Symtab functions that
309 // lookup symbols by name to indicate if they want trampolines. We also
310 // don't want any synthetic symbols with auto generated names in the
311 // name lookups.
312 if (symbol->IsTrampoline() || symbol->IsSyntheticWithAutoGeneratedName())
313 continue;
314
315 // If the symbol's name string matched a Mangled::ManglingScheme, it is
316 // stored in the mangled field.
317 Mangled &mangled = symbol->GetMangled();
318 if (ConstString name = mangled.GetMangledName()) {
319 name_to_index.Append(unique_cstr: name, value);
320
321 if (symbol->ContainsLinkerAnnotations()) {
322 // If the symbol has linker annotations, also add the version without
323 // the annotations.
324 ConstString stripped = ConstString(
325 m_objfile->StripLinkerSymbolAnnotations(symbol_name: name.GetStringRef()));
326 name_to_index.Append(unique_cstr: stripped, value);
327 }
328
329 const SymbolType type = symbol->GetType();
330 if (type == eSymbolTypeCode || type == eSymbolTypeResolver) {
331 if (mangled.GetRichManglingInfo(context&: rmc, skip_mangled_name: lldb_skip_name)) {
332 RegisterMangledNameEntry(value, class_contexts, backlog, rmc);
333 continue;
334 }
335 }
336 }
337
338 // Symbol name strings that didn't match a Mangled::ManglingScheme, are
339 // stored in the demangled field.
340 if (ConstString name = mangled.GetDemangledName()) {
341 name_to_index.Append(unique_cstr: name, value);
342
343 if (symbol->ContainsLinkerAnnotations()) {
344 // If the symbol has linker annotations, also add the version without
345 // the annotations.
346 name = ConstString(
347 m_objfile->StripLinkerSymbolAnnotations(symbol_name: name.GetStringRef()));
348 name_to_index.Append(unique_cstr: name, value);
349 }
350
351 // If the demangled name turns out to be an ObjC name, and is a category
352 // name, add the version without categories to the index too.
353 for (Language *lang : languages) {
354 for (auto variant : lang->GetMethodNameVariants(method_name: name)) {
355 if (variant.GetType() & lldb::eFunctionNameTypeSelector)
356 selector_to_index.Append(unique_cstr: variant.GetName(), value);
357 else if (variant.GetType() & lldb::eFunctionNameTypeFull)
358 name_to_index.Append(unique_cstr: variant.GetName(), value);
359 else if (variant.GetType() & lldb::eFunctionNameTypeMethod)
360 method_to_index.Append(unique_cstr: variant.GetName(), value);
361 else if (variant.GetType() & lldb::eFunctionNameTypeBase)
362 basename_to_index.Append(unique_cstr: variant.GetName(), value);
363 }
364 }
365 }
366 }
367
368 for (const auto &record : backlog) {
369 RegisterBacklogEntry(entry: record.first, decl_context: record.second, class_contexts);
370 }
371
372 name_to_index.Sort();
373 name_to_index.SizeToFit();
374 selector_to_index.Sort();
375 selector_to_index.SizeToFit();
376 basename_to_index.Sort();
377 basename_to_index.SizeToFit();
378 method_to_index.Sort();
379 method_to_index.SizeToFit();
380 }
381}
382
383void Symtab::RegisterMangledNameEntry(
384 uint32_t value, std::set<const char *> &class_contexts,
385 std::vector<std::pair<NameToIndexMap::Entry, const char *>> &backlog,
386 RichManglingContext &rmc) {
387 // Only register functions that have a base name.
388 llvm::StringRef base_name = rmc.ParseFunctionBaseName();
389 if (base_name.empty())
390 return;
391
392 // The base name will be our entry's name.
393 NameToIndexMap::Entry entry(ConstString(base_name), value);
394 llvm::StringRef decl_context = rmc.ParseFunctionDeclContextName();
395
396 // Register functions with no context.
397 if (decl_context.empty()) {
398 // This has to be a basename
399 auto &basename_to_index =
400 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeBase);
401 basename_to_index.Append(e: entry);
402 // If there is no context (no namespaces or class scopes that come before
403 // the function name) then this also could be a fullname.
404 auto &name_to_index = GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeNone);
405 name_to_index.Append(e: entry);
406 return;
407 }
408
409 // Make sure we have a pool-string pointer and see if we already know the
410 // context name.
411 const char *decl_context_ccstr = ConstString(decl_context).GetCString();
412 auto it = class_contexts.find(x: decl_context_ccstr);
413
414 auto &method_to_index =
415 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeMethod);
416 // Register constructors and destructors. They are methods and create
417 // declaration contexts.
418 if (rmc.IsCtorOrDtor()) {
419 method_to_index.Append(e: entry);
420 if (it == class_contexts.end())
421 class_contexts.insert(position: it, x: decl_context_ccstr);
422 return;
423 }
424
425 // Register regular methods with a known declaration context.
426 if (it != class_contexts.end()) {
427 method_to_index.Append(e: entry);
428 return;
429 }
430
431 // Regular methods in unknown declaration contexts are put to the backlog. We
432 // will revisit them once we processed all remaining symbols.
433 backlog.push_back(x: std::make_pair(x&: entry, y&: decl_context_ccstr));
434}
435
436void Symtab::RegisterBacklogEntry(
437 const NameToIndexMap::Entry &entry, const char *decl_context,
438 const std::set<const char *> &class_contexts) {
439 auto &method_to_index =
440 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeMethod);
441 auto it = class_contexts.find(x: decl_context);
442 if (it != class_contexts.end()) {
443 method_to_index.Append(e: entry);
444 } else {
445 // If we got here, we have something that had a context (was inside
446 // a namespace or class) yet we don't know the entry
447 method_to_index.Append(e: entry);
448 auto &basename_to_index =
449 GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeBase);
450 basename_to_index.Append(e: entry);
451 }
452}
453
454void Symtab::PreloadSymbols() {
455 std::lock_guard<std::recursive_mutex> guard(m_mutex);
456 InitNameIndexes();
457}
458
459void Symtab::AppendSymbolNamesToMap(const IndexCollection &indexes,
460 bool add_demangled, bool add_mangled,
461 NameToIndexMap &name_to_index_map) const {
462 LLDB_SCOPED_TIMER();
463 if (add_demangled || add_mangled) {
464 std::lock_guard<std::recursive_mutex> guard(m_mutex);
465
466 // Create the name index vector to be able to quickly search by name
467 const size_t num_indexes = indexes.size();
468 for (size_t i = 0; i < num_indexes; ++i) {
469 uint32_t value = indexes[i];
470 assert(i < m_symbols.size());
471 const Symbol *symbol = &m_symbols[value];
472
473 const Mangled &mangled = symbol->GetMangled();
474 if (add_demangled) {
475 if (ConstString name = mangled.GetDemangledName())
476 name_to_index_map.Append(unique_cstr: name, value);
477 }
478
479 if (add_mangled) {
480 if (ConstString name = mangled.GetMangledName())
481 name_to_index_map.Append(unique_cstr: name, value);
482 }
483 }
484 }
485}
486
487uint32_t Symtab::AppendSymbolIndexesWithType(SymbolType symbol_type,
488 std::vector<uint32_t> &indexes,
489 uint32_t start_idx,
490 uint32_t end_index) const {
491 std::lock_guard<std::recursive_mutex> guard(m_mutex);
492
493 uint32_t prev_size = indexes.size();
494
495 const uint32_t count = std::min<uint32_t>(a: m_symbols.size(), b: end_index);
496
497 for (uint32_t i = start_idx; i < count; ++i) {
498 if (symbol_type == eSymbolTypeAny || m_symbols[i].GetType() == symbol_type)
499 indexes.push_back(x: i);
500 }
501
502 return indexes.size() - prev_size;
503}
504
505uint32_t Symtab::AppendSymbolIndexesWithTypeAndFlagsValue(
506 SymbolType symbol_type, uint32_t flags_value,
507 std::vector<uint32_t> &indexes, uint32_t start_idx,
508 uint32_t end_index) const {
509 std::lock_guard<std::recursive_mutex> guard(m_mutex);
510
511 uint32_t prev_size = indexes.size();
512
513 const uint32_t count = std::min<uint32_t>(a: m_symbols.size(), b: end_index);
514
515 for (uint32_t i = start_idx; i < count; ++i) {
516 if ((symbol_type == eSymbolTypeAny ||
517 m_symbols[i].GetType() == symbol_type) &&
518 m_symbols[i].GetFlags() == flags_value)
519 indexes.push_back(x: i);
520 }
521
522 return indexes.size() - prev_size;
523}
524
525uint32_t Symtab::AppendSymbolIndexesWithType(SymbolType symbol_type,
526 Debug symbol_debug_type,
527 Visibility symbol_visibility,
528 std::vector<uint32_t> &indexes,
529 uint32_t start_idx,
530 uint32_t end_index) const {
531 std::lock_guard<std::recursive_mutex> guard(m_mutex);
532
533 uint32_t prev_size = indexes.size();
534
535 const uint32_t count = std::min<uint32_t>(a: m_symbols.size(), b: end_index);
536
537 for (uint32_t i = start_idx; i < count; ++i) {
538 if (symbol_type == eSymbolTypeAny ||
539 m_symbols[i].GetType() == symbol_type) {
540 if (CheckSymbolAtIndex(idx: i, symbol_debug_type, symbol_visibility))
541 indexes.push_back(x: i);
542 }
543 }
544
545 return indexes.size() - prev_size;
546}
547
548uint32_t Symtab::GetIndexForSymbol(const Symbol *symbol) const {
549 if (!m_symbols.empty()) {
550 const Symbol *first_symbol = &m_symbols[0];
551 if (symbol >= first_symbol && symbol < first_symbol + m_symbols.size())
552 return symbol - first_symbol;
553 }
554 return UINT32_MAX;
555}
556
557struct SymbolSortInfo {
558 const bool sort_by_load_addr;
559 const Symbol *symbols;
560};
561
562namespace {
563struct SymbolIndexComparator {
564 const std::vector<Symbol> &symbols;
565 std::vector<lldb::addr_t> &addr_cache;
566
567 // Getting from the symbol to the Address to the File Address involves some
568 // work. Since there are potentially many symbols here, and we're using this
569 // for sorting so we're going to be computing the address many times, cache
570 // that in addr_cache. The array passed in has to be the same size as the
571 // symbols array passed into the member variable symbols, and should be
572 // initialized with LLDB_INVALID_ADDRESS.
573 // NOTE: You have to make addr_cache externally and pass it in because
574 // std::stable_sort
575 // makes copies of the comparator it is initially passed in, and you end up
576 // spending huge amounts of time copying this array...
577
578 SymbolIndexComparator(const std::vector<Symbol> &s,
579 std::vector<lldb::addr_t> &a)
580 : symbols(s), addr_cache(a) {
581 assert(symbols.size() == addr_cache.size());
582 }
583 bool operator()(uint32_t index_a, uint32_t index_b) {
584 addr_t value_a = addr_cache[index_a];
585 if (value_a == LLDB_INVALID_ADDRESS) {
586 value_a = symbols[index_a].GetAddressRef().GetFileAddress();
587 addr_cache[index_a] = value_a;
588 }
589
590 addr_t value_b = addr_cache[index_b];
591 if (value_b == LLDB_INVALID_ADDRESS) {
592 value_b = symbols[index_b].GetAddressRef().GetFileAddress();
593 addr_cache[index_b] = value_b;
594 }
595
596 if (value_a == value_b) {
597 // The if the values are equal, use the original symbol user ID
598 lldb::user_id_t uid_a = symbols[index_a].GetID();
599 lldb::user_id_t uid_b = symbols[index_b].GetID();
600 if (uid_a < uid_b)
601 return true;
602 if (uid_a > uid_b)
603 return false;
604 return false;
605 } else if (value_a < value_b)
606 return true;
607
608 return false;
609 }
610};
611}
612
613void Symtab::SortSymbolIndexesByValue(std::vector<uint32_t> &indexes,
614 bool remove_duplicates) const {
615 std::lock_guard<std::recursive_mutex> guard(m_mutex);
616 LLDB_SCOPED_TIMER();
617 // No need to sort if we have zero or one items...
618 if (indexes.size() <= 1)
619 return;
620
621 // Sort the indexes in place using std::stable_sort.
622 // NOTE: The use of std::stable_sort instead of llvm::sort here is strictly
623 // for performance, not correctness. The indexes vector tends to be "close"
624 // to sorted, which the stable sort handles better.
625
626 std::vector<lldb::addr_t> addr_cache(m_symbols.size(), LLDB_INVALID_ADDRESS);
627
628 SymbolIndexComparator comparator(m_symbols, addr_cache);
629 std::stable_sort(first: indexes.begin(), last: indexes.end(), comp: comparator);
630
631 // Remove any duplicates if requested
632 if (remove_duplicates) {
633 auto last = std::unique(first: indexes.begin(), last: indexes.end());
634 indexes.erase(first: last, last: indexes.end());
635 }
636}
637
638uint32_t Symtab::GetNameIndexes(ConstString symbol_name,
639 std::vector<uint32_t> &indexes) {
640 auto &name_to_index = GetNameToSymbolIndexMap(type: lldb::eFunctionNameTypeNone);
641 const uint32_t count = name_to_index.GetValues(unique_cstr: symbol_name, values&: indexes);
642 if (count)
643 return count;
644 // Synthetic symbol names are not added to the name indexes, but they start
645 // with a prefix and end with a the symbol UserID. This allows users to find
646 // these symbols without having to add them to the name indexes. These
647 // queries will not happen very often since the names don't mean anything, so
648 // performance is not paramount in this case.
649 llvm::StringRef name = symbol_name.GetStringRef();
650 // String the synthetic prefix if the name starts with it.
651 if (!name.consume_front(Prefix: Symbol::GetSyntheticSymbolPrefix()))
652 return 0; // Not a synthetic symbol name
653
654 // Extract the user ID from the symbol name
655 unsigned long long uid = 0;
656 if (getAsUnsignedInteger(Str: name, /*Radix=*/10, Result&: uid))
657 return 0; // Failed to extract the user ID as an integer
658 Symbol *symbol = FindSymbolByID(symbol_uid: uid);
659 if (symbol == nullptr)
660 return 0;
661 const uint32_t symbol_idx = GetIndexForSymbol(symbol);
662 if (symbol_idx == UINT32_MAX)
663 return 0;
664 indexes.push_back(x: symbol_idx);
665 return 1;
666}
667
668uint32_t Symtab::AppendSymbolIndexesWithName(ConstString symbol_name,
669 std::vector<uint32_t> &indexes) {
670 std::lock_guard<std::recursive_mutex> guard(m_mutex);
671
672 if (symbol_name) {
673 if (!m_name_indexes_computed)
674 InitNameIndexes();
675
676 return GetNameIndexes(symbol_name, indexes);
677 }
678 return 0;
679}
680
681uint32_t Symtab::AppendSymbolIndexesWithName(ConstString symbol_name,
682 Debug symbol_debug_type,
683 Visibility symbol_visibility,
684 std::vector<uint32_t> &indexes) {
685 std::lock_guard<std::recursive_mutex> guard(m_mutex);
686
687 LLDB_SCOPED_TIMER();
688 if (symbol_name) {
689 const size_t old_size = indexes.size();
690 if (!m_name_indexes_computed)
691 InitNameIndexes();
692
693 std::vector<uint32_t> all_name_indexes;
694 const size_t name_match_count =
695 GetNameIndexes(symbol_name, indexes&: all_name_indexes);
696 for (size_t i = 0; i < name_match_count; ++i) {
697 if (CheckSymbolAtIndex(idx: all_name_indexes[i], symbol_debug_type,
698 symbol_visibility))
699 indexes.push_back(x: all_name_indexes[i]);
700 }
701 return indexes.size() - old_size;
702 }
703 return 0;
704}
705
706uint32_t
707Symtab::AppendSymbolIndexesWithNameAndType(ConstString symbol_name,
708 SymbolType symbol_type,
709 std::vector<uint32_t> &indexes) {
710 std::lock_guard<std::recursive_mutex> guard(m_mutex);
711
712 if (AppendSymbolIndexesWithName(symbol_name, indexes) > 0) {
713 std::vector<uint32_t>::iterator pos = indexes.begin();
714 while (pos != indexes.end()) {
715 if (symbol_type == eSymbolTypeAny ||
716 m_symbols[*pos].GetType() == symbol_type)
717 ++pos;
718 else
719 pos = indexes.erase(position: pos);
720 }
721 }
722 return indexes.size();
723}
724
725uint32_t Symtab::AppendSymbolIndexesWithNameAndType(
726 ConstString symbol_name, SymbolType symbol_type,
727 Debug symbol_debug_type, Visibility symbol_visibility,
728 std::vector<uint32_t> &indexes) {
729 std::lock_guard<std::recursive_mutex> guard(m_mutex);
730
731 if (AppendSymbolIndexesWithName(symbol_name, symbol_debug_type,
732 symbol_visibility, indexes) > 0) {
733 std::vector<uint32_t>::iterator pos = indexes.begin();
734 while (pos != indexes.end()) {
735 if (symbol_type == eSymbolTypeAny ||
736 m_symbols[*pos].GetType() == symbol_type)
737 ++pos;
738 else
739 pos = indexes.erase(position: pos);
740 }
741 }
742 return indexes.size();
743}
744
745uint32_t Symtab::AppendSymbolIndexesMatchingRegExAndType(
746 const RegularExpression &regexp, SymbolType symbol_type,
747 std::vector<uint32_t> &indexes, Mangled::NamePreference name_preference) {
748 std::lock_guard<std::recursive_mutex> guard(m_mutex);
749
750 uint32_t prev_size = indexes.size();
751 uint32_t sym_end = m_symbols.size();
752
753 for (uint32_t i = 0; i < sym_end; i++) {
754 if (symbol_type == eSymbolTypeAny ||
755 m_symbols[i].GetType() == symbol_type) {
756 const char *name =
757 m_symbols[i].GetMangled().GetName(preference: name_preference).AsCString();
758 if (name) {
759 if (regexp.Execute(string: name))
760 indexes.push_back(x: i);
761 }
762 }
763 }
764 return indexes.size() - prev_size;
765}
766
767uint32_t Symtab::AppendSymbolIndexesMatchingRegExAndType(
768 const RegularExpression &regexp, SymbolType symbol_type,
769 Debug symbol_debug_type, Visibility symbol_visibility,
770 std::vector<uint32_t> &indexes, Mangled::NamePreference name_preference) {
771 std::lock_guard<std::recursive_mutex> guard(m_mutex);
772
773 uint32_t prev_size = indexes.size();
774 uint32_t sym_end = m_symbols.size();
775
776 for (uint32_t i = 0; i < sym_end; i++) {
777 if (symbol_type == eSymbolTypeAny ||
778 m_symbols[i].GetType() == symbol_type) {
779 if (!CheckSymbolAtIndex(idx: i, symbol_debug_type, symbol_visibility))
780 continue;
781
782 const char *name =
783 m_symbols[i].GetMangled().GetName(preference: name_preference).AsCString();
784 if (name) {
785 if (regexp.Execute(string: name))
786 indexes.push_back(x: i);
787 }
788 }
789 }
790 return indexes.size() - prev_size;
791}
792
793Symbol *Symtab::FindSymbolWithType(SymbolType symbol_type,
794 Debug symbol_debug_type,
795 Visibility symbol_visibility,
796 uint32_t &start_idx) {
797 std::lock_guard<std::recursive_mutex> guard(m_mutex);
798
799 const size_t count = m_symbols.size();
800 for (size_t idx = start_idx; idx < count; ++idx) {
801 if (symbol_type == eSymbolTypeAny ||
802 m_symbols[idx].GetType() == symbol_type) {
803 if (CheckSymbolAtIndex(idx, symbol_debug_type, symbol_visibility)) {
804 start_idx = idx;
805 return &m_symbols[idx];
806 }
807 }
808 }
809 return nullptr;
810}
811
812void
813Symtab::FindAllSymbolsWithNameAndType(ConstString name,
814 SymbolType symbol_type,
815 std::vector<uint32_t> &symbol_indexes) {
816 std::lock_guard<std::recursive_mutex> guard(m_mutex);
817
818 // Initialize all of the lookup by name indexes before converting NAME to a
819 // uniqued string NAME_STR below.
820 if (!m_name_indexes_computed)
821 InitNameIndexes();
822
823 if (name) {
824 // The string table did have a string that matched, but we need to check
825 // the symbols and match the symbol_type if any was given.
826 AppendSymbolIndexesWithNameAndType(symbol_name: name, symbol_type, indexes&: symbol_indexes);
827 }
828}
829
830void Symtab::FindAllSymbolsWithNameAndType(
831 ConstString name, SymbolType symbol_type, Debug symbol_debug_type,
832 Visibility symbol_visibility, std::vector<uint32_t> &symbol_indexes) {
833 std::lock_guard<std::recursive_mutex> guard(m_mutex);
834
835 LLDB_SCOPED_TIMER();
836 // Initialize all of the lookup by name indexes before converting NAME to a
837 // uniqued string NAME_STR below.
838 if (!m_name_indexes_computed)
839 InitNameIndexes();
840
841 if (name) {
842 // The string table did have a string that matched, but we need to check
843 // the symbols and match the symbol_type if any was given.
844 AppendSymbolIndexesWithNameAndType(symbol_name: name, symbol_type, symbol_debug_type,
845 symbol_visibility, indexes&: symbol_indexes);
846 }
847}
848
849void Symtab::FindAllSymbolsMatchingRexExAndType(
850 const RegularExpression &regex, SymbolType symbol_type,
851 Debug symbol_debug_type, Visibility symbol_visibility,
852 std::vector<uint32_t> &symbol_indexes,
853 Mangled::NamePreference name_preference) {
854 std::lock_guard<std::recursive_mutex> guard(m_mutex);
855
856 AppendSymbolIndexesMatchingRegExAndType(regexp: regex, symbol_type, symbol_debug_type,
857 symbol_visibility, indexes&: symbol_indexes,
858 name_preference);
859}
860
861Symbol *Symtab::FindFirstSymbolWithNameAndType(ConstString name,
862 SymbolType symbol_type,
863 Debug symbol_debug_type,
864 Visibility symbol_visibility) {
865 std::lock_guard<std::recursive_mutex> guard(m_mutex);
866 LLDB_SCOPED_TIMER();
867 if (!m_name_indexes_computed)
868 InitNameIndexes();
869
870 if (name) {
871 std::vector<uint32_t> matching_indexes;
872 // The string table did have a string that matched, but we need to check
873 // the symbols and match the symbol_type if any was given.
874 if (AppendSymbolIndexesWithNameAndType(symbol_name: name, symbol_type, symbol_debug_type,
875 symbol_visibility,
876 indexes&: matching_indexes)) {
877 std::vector<uint32_t>::const_iterator pos, end = matching_indexes.end();
878 for (pos = matching_indexes.begin(); pos != end; ++pos) {
879 Symbol *symbol = SymbolAtIndex(idx: *pos);
880
881 if (symbol->Compare(name, type: symbol_type))
882 return symbol;
883 }
884 }
885 }
886 return nullptr;
887}
888
889typedef struct {
890 const Symtab *symtab;
891 const addr_t file_addr;
892 Symbol *match_symbol;
893 const uint32_t *match_index_ptr;
894 addr_t match_offset;
895} SymbolSearchInfo;
896
897// Add all the section file start address & size to the RangeVector, recusively
898// adding any children sections.
899static void AddSectionsToRangeMap(SectionList *sectlist,
900 RangeVector<addr_t, addr_t> &section_ranges) {
901 const int num_sections = sectlist->GetNumSections(depth: 0);
902 for (int i = 0; i < num_sections; i++) {
903 SectionSP sect_sp = sectlist->GetSectionAtIndex(idx: i);
904 if (sect_sp) {
905 SectionList &child_sectlist = sect_sp->GetChildren();
906
907 // If this section has children, add the children to the RangeVector.
908 // Else add this section to the RangeVector.
909 if (child_sectlist.GetNumSections(depth: 0) > 0) {
910 AddSectionsToRangeMap(sectlist: &child_sectlist, section_ranges);
911 } else {
912 size_t size = sect_sp->GetByteSize();
913 if (size > 0) {
914 addr_t base_addr = sect_sp->GetFileAddress();
915 RangeVector<addr_t, addr_t>::Entry entry;
916 entry.SetRangeBase(base_addr);
917 entry.SetByteSize(size);
918 section_ranges.Append(entry);
919 }
920 }
921 }
922 }
923}
924
925void Symtab::InitAddressIndexes() {
926 // Protected function, no need to lock mutex...
927 if (!m_file_addr_to_index_computed && !m_symbols.empty()) {
928 m_file_addr_to_index_computed = true;
929
930 FileRangeToIndexMap::Entry entry;
931 const_iterator begin = m_symbols.begin();
932 const_iterator end = m_symbols.end();
933 for (const_iterator pos = m_symbols.begin(); pos != end; ++pos) {
934 if (pos->ValueIsAddress()) {
935 entry.SetRangeBase(pos->GetAddressRef().GetFileAddress());
936 entry.SetByteSize(pos->GetByteSize());
937 entry.data = std::distance(first: begin, last: pos);
938 m_file_addr_to_index.Append(entry);
939 }
940 }
941 const size_t num_entries = m_file_addr_to_index.GetSize();
942 if (num_entries > 0) {
943 m_file_addr_to_index.Sort();
944
945 // Create a RangeVector with the start & size of all the sections for
946 // this objfile. We'll need to check this for any FileRangeToIndexMap
947 // entries with an uninitialized size, which could potentially be a large
948 // number so reconstituting the weak pointer is busywork when it is
949 // invariant information.
950 SectionList *sectlist = m_objfile->GetSectionList();
951 RangeVector<addr_t, addr_t> section_ranges;
952 if (sectlist) {
953 AddSectionsToRangeMap(sectlist, section_ranges);
954 section_ranges.Sort();
955 }
956
957 // Iterate through the FileRangeToIndexMap and fill in the size for any
958 // entries that didn't already have a size from the Symbol (e.g. if we
959 // have a plain linker symbol with an address only, instead of debug info
960 // where we get an address and a size and a type, etc.)
961 for (size_t i = 0; i < num_entries; i++) {
962 FileRangeToIndexMap::Entry *entry =
963 m_file_addr_to_index.GetMutableEntryAtIndex(i);
964 if (entry->GetByteSize() == 0) {
965 addr_t curr_base_addr = entry->GetRangeBase();
966 const RangeVector<addr_t, addr_t>::Entry *containing_section =
967 section_ranges.FindEntryThatContains(addr: curr_base_addr);
968
969 // Use the end of the section as the default max size of the symbol
970 addr_t sym_size = 0;
971 if (containing_section) {
972 sym_size =
973 containing_section->GetByteSize() -
974 (entry->GetRangeBase() - containing_section->GetRangeBase());
975 }
976
977 for (size_t j = i; j < num_entries; j++) {
978 FileRangeToIndexMap::Entry *next_entry =
979 m_file_addr_to_index.GetMutableEntryAtIndex(i: j);
980 addr_t next_base_addr = next_entry->GetRangeBase();
981 if (next_base_addr > curr_base_addr) {
982 addr_t size_to_next_symbol = next_base_addr - curr_base_addr;
983
984 // Take the difference between this symbol and the next one as
985 // its size, if it is less than the size of the section.
986 if (sym_size == 0 || size_to_next_symbol < sym_size) {
987 sym_size = size_to_next_symbol;
988 }
989 break;
990 }
991 }
992
993 if (sym_size > 0) {
994 entry->SetByteSize(sym_size);
995 Symbol &symbol = m_symbols[entry->data];
996 symbol.SetByteSize(sym_size);
997 symbol.SetSizeIsSynthesized(true);
998 }
999 }
1000 }
1001
1002 // Sort again in case the range size changes the ordering
1003 m_file_addr_to_index.Sort();
1004 }
1005 }
1006}
1007
1008void Symtab::Finalize() {
1009 std::lock_guard<std::recursive_mutex> guard(m_mutex);
1010 // Calculate the size of symbols inside InitAddressIndexes.
1011 InitAddressIndexes();
1012 // Shrink to fit the symbols so we don't waste memory
1013 m_symbols.shrink_to_fit();
1014 SaveToCache();
1015}
1016
1017Symbol *Symtab::FindSymbolAtFileAddress(addr_t file_addr) {
1018 std::lock_guard<std::recursive_mutex> guard(m_mutex);
1019 if (!m_file_addr_to_index_computed)
1020 InitAddressIndexes();
1021
1022 const FileRangeToIndexMap::Entry *entry =
1023 m_file_addr_to_index.FindEntryStartsAt(addr: file_addr);
1024 if (entry) {
1025 Symbol *symbol = SymbolAtIndex(idx: entry->data);
1026 if (symbol->GetFileAddress() == file_addr)
1027 return symbol;
1028 }
1029 return nullptr;
1030}
1031
1032Symbol *Symtab::FindSymbolContainingFileAddress(addr_t file_addr) {
1033 std::lock_guard<std::recursive_mutex> guard(m_mutex);
1034
1035 if (!m_file_addr_to_index_computed)
1036 InitAddressIndexes();
1037
1038 const FileRangeToIndexMap::Entry *entry =
1039 m_file_addr_to_index.FindEntryThatContains(addr: file_addr);
1040 if (entry) {
1041 Symbol *symbol = SymbolAtIndex(idx: entry->data);
1042 if (symbol->ContainsFileAddress(file_addr))
1043 return symbol;
1044 }
1045 return nullptr;
1046}
1047
1048void Symtab::ForEachSymbolContainingFileAddress(
1049 addr_t file_addr, std::function<bool(Symbol *)> const &callback) {
1050 std::lock_guard<std::recursive_mutex> guard(m_mutex);
1051
1052 if (!m_file_addr_to_index_computed)
1053 InitAddressIndexes();
1054
1055 std::vector<uint32_t> all_addr_indexes;
1056
1057 // Get all symbols with file_addr
1058 const size_t addr_match_count =
1059 m_file_addr_to_index.FindEntryIndexesThatContain(addr: file_addr,
1060 indexes&: all_addr_indexes);
1061
1062 for (size_t i = 0; i < addr_match_count; ++i) {
1063 Symbol *symbol = SymbolAtIndex(idx: all_addr_indexes[i]);
1064 if (symbol->ContainsFileAddress(file_addr)) {
1065 if (!callback(symbol))
1066 break;
1067 }
1068 }
1069}
1070
1071void Symtab::SymbolIndicesToSymbolContextList(
1072 std::vector<uint32_t> &symbol_indexes, SymbolContextList &sc_list) {
1073 // No need to protect this call using m_mutex all other method calls are
1074 // already thread safe.
1075
1076 const bool merge_symbol_into_function = true;
1077 size_t num_indices = symbol_indexes.size();
1078 if (num_indices > 0) {
1079 SymbolContext sc;
1080 sc.module_sp = m_objfile->GetModule();
1081 for (size_t i = 0; i < num_indices; i++) {
1082 sc.symbol = SymbolAtIndex(idx: symbol_indexes[i]);
1083 if (sc.symbol)
1084 sc_list.AppendIfUnique(sc, merge_symbol_into_function);
1085 }
1086 }
1087}
1088
1089void Symtab::FindFunctionSymbols(ConstString name, uint32_t name_type_mask,
1090 SymbolContextList &sc_list) {
1091 std::vector<uint32_t> symbol_indexes;
1092
1093 // eFunctionNameTypeAuto should be pre-resolved by a call to
1094 // Module::LookupInfo::LookupInfo()
1095 assert((name_type_mask & eFunctionNameTypeAuto) == 0);
1096
1097 if (name_type_mask & (eFunctionNameTypeBase | eFunctionNameTypeFull)) {
1098 std::vector<uint32_t> temp_symbol_indexes;
1099 FindAllSymbolsWithNameAndType(name, symbol_type: eSymbolTypeAny, symbol_indexes&: temp_symbol_indexes);
1100
1101 unsigned temp_symbol_indexes_size = temp_symbol_indexes.size();
1102 if (temp_symbol_indexes_size > 0) {
1103 std::lock_guard<std::recursive_mutex> guard(m_mutex);
1104 for (unsigned i = 0; i < temp_symbol_indexes_size; i++) {
1105 SymbolContext sym_ctx;
1106 sym_ctx.symbol = SymbolAtIndex(idx: temp_symbol_indexes[i]);
1107 if (sym_ctx.symbol) {
1108 switch (sym_ctx.symbol->GetType()) {
1109 case eSymbolTypeCode:
1110 case eSymbolTypeResolver:
1111 case eSymbolTypeReExported:
1112 case eSymbolTypeAbsolute:
1113 symbol_indexes.push_back(x: temp_symbol_indexes[i]);
1114 break;
1115 default:
1116 break;
1117 }
1118 }
1119 }
1120 }
1121 }
1122
1123 if (!m_name_indexes_computed)
1124 InitNameIndexes();
1125
1126 for (lldb::FunctionNameType type :
1127 {lldb::eFunctionNameTypeBase, lldb::eFunctionNameTypeMethod,
1128 lldb::eFunctionNameTypeSelector}) {
1129 if (name_type_mask & type) {
1130 auto map = GetNameToSymbolIndexMap(type);
1131
1132 const UniqueCStringMap<uint32_t>::Entry *match;
1133 for (match = map.FindFirstValueForName(unique_cstr: name); match != nullptr;
1134 match = map.FindNextValueForName(entry_ptr: match)) {
1135 symbol_indexes.push_back(x: match->value);
1136 }
1137 }
1138 }
1139
1140 if (!symbol_indexes.empty()) {
1141 llvm::sort(C&: symbol_indexes);
1142 symbol_indexes.erase(
1143 first: std::unique(first: symbol_indexes.begin(), last: symbol_indexes.end()),
1144 last: symbol_indexes.end());
1145 SymbolIndicesToSymbolContextList(symbol_indexes, sc_list);
1146 }
1147}
1148
1149const Symbol *Symtab::GetParent(Symbol *child_symbol) const {
1150 uint32_t child_idx = GetIndexForSymbol(symbol: child_symbol);
1151 if (child_idx != UINT32_MAX && child_idx > 0) {
1152 for (uint32_t idx = child_idx - 1; idx != UINT32_MAX; --idx) {
1153 const Symbol *symbol = SymbolAtIndex(idx);
1154 const uint32_t sibling_idx = symbol->GetSiblingIndex();
1155 if (sibling_idx != UINT32_MAX && sibling_idx > child_idx)
1156 return symbol;
1157 }
1158 }
1159 return nullptr;
1160}
1161
1162std::string Symtab::GetCacheKey() {
1163 std::string key;
1164 llvm::raw_string_ostream strm(key);
1165 // Symbol table can come from different object files for the same module. A
1166 // module can have one object file as the main executable and might have
1167 // another object file in a separate symbol file.
1168 strm << m_objfile->GetModule()->GetCacheKey() << "-symtab-"
1169 << llvm::format_hex(N: m_objfile->GetCacheHash(), Width: 10);
1170 return strm.str();
1171}
1172
1173void Symtab::SaveToCache() {
1174 DataFileCache *cache = Module::GetIndexCache();
1175 if (!cache)
1176 return; // Caching is not enabled.
1177 InitNameIndexes(); // Init the name indexes so we can cache them as well.
1178 const auto byte_order = endian::InlHostByteOrder();
1179 DataEncoder file(byte_order, /*addr_size=*/8);
1180 // Encode will return false if the symbol table's object file doesn't have
1181 // anything to make a signature from.
1182 if (Encode(encoder&: file))
1183 if (cache->SetCachedData(key: GetCacheKey(), data: file.GetData()))
1184 SetWasSavedToCache();
1185}
1186
1187constexpr llvm::StringLiteral kIdentifierCStrMap("CMAP");
1188
1189static void EncodeCStrMap(DataEncoder &encoder, ConstStringTable &strtab,
1190 const UniqueCStringMap<uint32_t> &cstr_map) {
1191 encoder.AppendData(data: kIdentifierCStrMap);
1192 encoder.AppendU32(value: cstr_map.GetSize());
1193 for (const auto &entry: cstr_map) {
1194 // Make sure there are no empty strings.
1195 assert((bool)entry.cstring);
1196 encoder.AppendU32(value: strtab.Add(s: entry.cstring));
1197 encoder.AppendU32(value: entry.value);
1198 }
1199}
1200
1201bool DecodeCStrMap(const DataExtractor &data, lldb::offset_t *offset_ptr,
1202 const StringTableReader &strtab,
1203 UniqueCStringMap<uint32_t> &cstr_map) {
1204 llvm::StringRef identifier((const char *)data.GetData(offset_ptr, length: 4), 4);
1205 if (identifier != kIdentifierCStrMap)
1206 return false;
1207 const uint32_t count = data.GetU32(offset_ptr);
1208 cstr_map.Reserve(n: count);
1209 for (uint32_t i=0; i<count; ++i)
1210 {
1211 llvm::StringRef str(strtab.Get(offset: data.GetU32(offset_ptr)));
1212 uint32_t value = data.GetU32(offset_ptr);
1213 // No empty strings in the name indexes in Symtab
1214 if (str.empty())
1215 return false;
1216 cstr_map.Append(unique_cstr: ConstString(str), value);
1217 }
1218 // We must sort the UniqueCStringMap after decoding it since it is a vector
1219 // of UniqueCStringMap::Entry objects which contain a ConstString and type T.
1220 // ConstString objects are sorted by "const char *" and then type T and
1221 // the "const char *" are point values that will depend on the order in which
1222 // ConstString objects are created and in which of the 256 string pools they
1223 // are created in. So after we decode all of the entries, we must sort the
1224 // name map to ensure name lookups succeed. If we encode and decode within
1225 // the same process we wouldn't need to sort, so unit testing didn't catch
1226 // this issue when first checked in.
1227 cstr_map.Sort();
1228 return true;
1229}
1230
1231constexpr llvm::StringLiteral kIdentifierSymbolTable("SYMB");
1232constexpr uint32_t CURRENT_CACHE_VERSION = 1;
1233
1234/// The encoding format for the symbol table is as follows:
1235///
1236/// Signature signature;
1237/// ConstStringTable strtab;
1238/// Identifier four character code: 'SYMB'
1239/// uint32_t version;
1240/// uint32_t num_symbols;
1241/// Symbol symbols[num_symbols];
1242/// uint8_t num_cstr_maps;
1243/// UniqueCStringMap<uint32_t> cstr_maps[num_cstr_maps]
1244bool Symtab::Encode(DataEncoder &encoder) const {
1245 // Name indexes must be computed before calling this function.
1246 assert(m_name_indexes_computed);
1247
1248 // Encode the object file's signature
1249 CacheSignature signature(m_objfile);
1250 if (!signature.Encode(encoder))
1251 return false;
1252 ConstStringTable strtab;
1253
1254 // Encoder the symbol table into a separate encoder first. This allows us
1255 // gather all of the strings we willl need in "strtab" as we will need to
1256 // write the string table out before the symbol table.
1257 DataEncoder symtab_encoder(encoder.GetByteOrder(),
1258 encoder.GetAddressByteSize());
1259 symtab_encoder.AppendData(data: kIdentifierSymbolTable);
1260 // Encode the symtab data version.
1261 symtab_encoder.AppendU32(value: CURRENT_CACHE_VERSION);
1262 // Encode the number of symbols.
1263 symtab_encoder.AppendU32(value: m_symbols.size());
1264 // Encode the symbol data for all symbols.
1265 for (const auto &symbol: m_symbols)
1266 symbol.Encode(encoder&: symtab_encoder, strtab);
1267
1268 // Emit a byte for how many C string maps we emit. We will fix this up after
1269 // we emit the C string maps since we skip emitting C string maps if they are
1270 // empty.
1271 size_t num_cmaps_offset = symtab_encoder.GetByteSize();
1272 uint8_t num_cmaps = 0;
1273 symtab_encoder.AppendU8(value: 0);
1274 for (const auto &pair: m_name_to_symbol_indices) {
1275 if (pair.second.IsEmpty())
1276 continue;
1277 ++num_cmaps;
1278 symtab_encoder.AppendU8(value: pair.first);
1279 EncodeCStrMap(encoder&: symtab_encoder, strtab, cstr_map: pair.second);
1280 }
1281 if (num_cmaps > 0)
1282 symtab_encoder.PutU8(offset: num_cmaps_offset, value: num_cmaps);
1283
1284 // Now that all strings have been gathered, we will emit the string table.
1285 strtab.Encode(encoder);
1286 // Followed by the symbol table data.
1287 encoder.AppendData(data: symtab_encoder.GetData());
1288 return true;
1289}
1290
1291bool Symtab::Decode(const DataExtractor &data, lldb::offset_t *offset_ptr,
1292 bool &signature_mismatch) {
1293 signature_mismatch = false;
1294 CacheSignature signature;
1295 StringTableReader strtab;
1296 { // Scope for "elapsed" object below so it can measure the time parse.
1297 ElapsedTime elapsed(m_objfile->GetModule()->GetSymtabParseTime());
1298 if (!signature.Decode(data, offset_ptr))
1299 return false;
1300 if (CacheSignature(m_objfile) != signature) {
1301 signature_mismatch = true;
1302 return false;
1303 }
1304 // We now decode the string table for all strings in the data cache file.
1305 if (!strtab.Decode(data, offset_ptr))
1306 return false;
1307
1308 // And now we can decode the symbol table with string table we just decoded.
1309 llvm::StringRef identifier((const char *)data.GetData(offset_ptr, length: 4), 4);
1310 if (identifier != kIdentifierSymbolTable)
1311 return false;
1312 const uint32_t version = data.GetU32(offset_ptr);
1313 if (version != CURRENT_CACHE_VERSION)
1314 return false;
1315 const uint32_t num_symbols = data.GetU32(offset_ptr);
1316 if (num_symbols == 0)
1317 return true;
1318 m_symbols.resize(new_size: num_symbols);
1319 SectionList *sections = m_objfile->GetModule()->GetSectionList();
1320 for (uint32_t i=0; i<num_symbols; ++i) {
1321 if (!m_symbols[i].Decode(data, offset_ptr, section_list: sections, strtab))
1322 return false;
1323 }
1324 }
1325
1326 { // Scope for "elapsed" object below so it can measure the time to index.
1327 ElapsedTime elapsed(m_objfile->GetModule()->GetSymtabIndexTime());
1328 const uint8_t num_cstr_maps = data.GetU8(offset_ptr);
1329 for (uint8_t i=0; i<num_cstr_maps; ++i) {
1330 uint8_t type = data.GetU8(offset_ptr);
1331 UniqueCStringMap<uint32_t> &cstr_map =
1332 GetNameToSymbolIndexMap(type: (lldb::FunctionNameType)type);
1333 if (!DecodeCStrMap(data, offset_ptr, strtab, cstr_map))
1334 return false;
1335 }
1336 m_name_indexes_computed = true;
1337 }
1338 return true;
1339}
1340
1341bool Symtab::LoadFromCache() {
1342 DataFileCache *cache = Module::GetIndexCache();
1343 if (!cache)
1344 return false;
1345
1346 std::unique_ptr<llvm::MemoryBuffer> mem_buffer_up =
1347 cache->GetCachedData(key: GetCacheKey());
1348 if (!mem_buffer_up)
1349 return false;
1350 DataExtractor data(mem_buffer_up->getBufferStart(),
1351 mem_buffer_up->getBufferSize(),
1352 m_objfile->GetByteOrder(),
1353 m_objfile->GetAddressByteSize());
1354 bool signature_mismatch = false;
1355 lldb::offset_t offset = 0;
1356 const bool result = Decode(data, offset_ptr: &offset, signature_mismatch);
1357 if (signature_mismatch)
1358 cache->RemoveCacheFile(key: GetCacheKey());
1359 if (result)
1360 SetWasLoadedFromCache();
1361 return result;
1362}
1363

source code of lldb/source/Symbol/Symtab.cpp