1 //===-- Symbol.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 "lldb/Symbol/Symbol.h" 10 11 #include "lldb/Core/Module.h" 12 #include "lldb/Core/ModuleSpec.h" 13 #include "lldb/Core/Section.h" 14 #include "lldb/Symbol/Function.h" 15 #include "lldb/Symbol/ObjectFile.h" 16 #include "lldb/Symbol/SymbolVendor.h" 17 #include "lldb/Symbol/Symtab.h" 18 #include "lldb/Target/Process.h" 19 #include "lldb/Target/Target.h" 20 #include "lldb/Utility/Stream.h" 21 22 using namespace lldb; 23 using namespace lldb_private; 24 25 Symbol::Symbol() 26 : SymbolContextScope(), m_uid(UINT32_MAX), m_type_data(0), 27 m_type_data_resolved(false), m_is_synthetic(false), m_is_debug(false), 28 m_is_external(false), m_size_is_sibling(false), 29 m_size_is_synthesized(false), m_size_is_valid(false), 30 m_demangled_is_synthesized(false), m_contains_linker_annotations(false), 31 m_is_weak(false), m_type(eSymbolTypeInvalid), m_mangled(), m_addr_range(), 32 m_flags() {} 33 34 Symbol::Symbol(uint32_t symID, llvm::StringRef name, SymbolType type, bool external, 35 bool is_debug, bool is_trampoline, bool is_artificial, 36 const lldb::SectionSP §ion_sp, addr_t offset, addr_t size, 37 bool size_is_valid, bool contains_linker_annotations, 38 uint32_t flags) 39 : SymbolContextScope(), m_uid(symID), m_type_data(0), 40 m_type_data_resolved(false), m_is_synthetic(is_artificial), 41 m_is_debug(is_debug), m_is_external(external), m_size_is_sibling(false), 42 m_size_is_synthesized(false), m_size_is_valid(size_is_valid || size > 0), 43 m_demangled_is_synthesized(false), 44 m_contains_linker_annotations(contains_linker_annotations), 45 m_is_weak(false), m_type(type), 46 m_mangled(name), 47 m_addr_range(section_sp, offset, size), m_flags(flags) {} 48 49 Symbol::Symbol(uint32_t symID, const Mangled &mangled, SymbolType type, 50 bool external, bool is_debug, bool is_trampoline, 51 bool is_artificial, const AddressRange &range, 52 bool size_is_valid, bool contains_linker_annotations, 53 uint32_t flags) 54 : SymbolContextScope(), m_uid(symID), m_type_data(0), 55 m_type_data_resolved(false), m_is_synthetic(is_artificial), 56 m_is_debug(is_debug), m_is_external(external), m_size_is_sibling(false), 57 m_size_is_synthesized(false), 58 m_size_is_valid(size_is_valid || range.GetByteSize() > 0), 59 m_demangled_is_synthesized(false), 60 m_contains_linker_annotations(contains_linker_annotations), 61 m_is_weak(false), m_type(type), m_mangled(mangled), m_addr_range(range), 62 m_flags(flags) {} 63 64 Symbol::Symbol(const Symbol &rhs) 65 : SymbolContextScope(rhs), m_uid(rhs.m_uid), m_type_data(rhs.m_type_data), 66 m_type_data_resolved(rhs.m_type_data_resolved), 67 m_is_synthetic(rhs.m_is_synthetic), m_is_debug(rhs.m_is_debug), 68 m_is_external(rhs.m_is_external), 69 m_size_is_sibling(rhs.m_size_is_sibling), m_size_is_synthesized(false), 70 m_size_is_valid(rhs.m_size_is_valid), 71 m_demangled_is_synthesized(rhs.m_demangled_is_synthesized), 72 m_contains_linker_annotations(rhs.m_contains_linker_annotations), 73 m_is_weak(rhs.m_is_weak), m_type(rhs.m_type), m_mangled(rhs.m_mangled), 74 m_addr_range(rhs.m_addr_range), m_flags(rhs.m_flags) {} 75 76 const Symbol &Symbol::operator=(const Symbol &rhs) { 77 if (this != &rhs) { 78 SymbolContextScope::operator=(rhs); 79 m_uid = rhs.m_uid; 80 m_type_data = rhs.m_type_data; 81 m_type_data_resolved = rhs.m_type_data_resolved; 82 m_is_synthetic = rhs.m_is_synthetic; 83 m_is_debug = rhs.m_is_debug; 84 m_is_external = rhs.m_is_external; 85 m_size_is_sibling = rhs.m_size_is_sibling; 86 m_size_is_synthesized = rhs.m_size_is_sibling; 87 m_size_is_valid = rhs.m_size_is_valid; 88 m_demangled_is_synthesized = rhs.m_demangled_is_synthesized; 89 m_contains_linker_annotations = rhs.m_contains_linker_annotations; 90 m_is_weak = rhs.m_is_weak; 91 m_type = rhs.m_type; 92 m_mangled = rhs.m_mangled; 93 m_addr_range = rhs.m_addr_range; 94 m_flags = rhs.m_flags; 95 } 96 return *this; 97 } 98 99 void Symbol::Clear() { 100 m_uid = UINT32_MAX; 101 m_mangled.Clear(); 102 m_type_data = 0; 103 m_type_data_resolved = false; 104 m_is_synthetic = false; 105 m_is_debug = false; 106 m_is_external = false; 107 m_size_is_sibling = false; 108 m_size_is_synthesized = false; 109 m_size_is_valid = false; 110 m_demangled_is_synthesized = false; 111 m_contains_linker_annotations = false; 112 m_is_weak = false; 113 m_type = eSymbolTypeInvalid; 114 m_flags = 0; 115 m_addr_range.Clear(); 116 } 117 118 bool Symbol::ValueIsAddress() const { 119 return m_addr_range.GetBaseAddress().GetSection().get() != nullptr; 120 } 121 122 ConstString Symbol::GetDisplayName() const { 123 return m_mangled.GetDisplayDemangledName(GetLanguage()); 124 } 125 126 ConstString Symbol::GetReExportedSymbolName() const { 127 if (m_type == eSymbolTypeReExported) { 128 // For eSymbolTypeReExported, the "const char *" from a ConstString is used 129 // as the offset in the address range base address. We can then make this 130 // back into a string that is the re-exported name. 131 intptr_t str_ptr = m_addr_range.GetBaseAddress().GetOffset(); 132 if (str_ptr != 0) 133 return ConstString((const char *)str_ptr); 134 else 135 return GetName(); 136 } 137 return ConstString(); 138 } 139 140 FileSpec Symbol::GetReExportedSymbolSharedLibrary() const { 141 if (m_type == eSymbolTypeReExported) { 142 // For eSymbolTypeReExported, the "const char *" from a ConstString is used 143 // as the offset in the address range base address. We can then make this 144 // back into a string that is the re-exported name. 145 intptr_t str_ptr = m_addr_range.GetByteSize(); 146 if (str_ptr != 0) 147 return FileSpec((const char *)str_ptr); 148 } 149 return FileSpec(); 150 } 151 152 void Symbol::SetReExportedSymbolName(ConstString name) { 153 SetType(eSymbolTypeReExported); 154 // For eSymbolTypeReExported, the "const char *" from a ConstString is used 155 // as the offset in the address range base address. 156 m_addr_range.GetBaseAddress().SetOffset((uintptr_t)name.GetCString()); 157 } 158 159 bool Symbol::SetReExportedSymbolSharedLibrary(const FileSpec &fspec) { 160 if (m_type == eSymbolTypeReExported) { 161 // For eSymbolTypeReExported, the "const char *" from a ConstString is used 162 // as the offset in the address range base address. 163 m_addr_range.SetByteSize( 164 (uintptr_t)ConstString(fspec.GetPath().c_str()).GetCString()); 165 return true; 166 } 167 return false; 168 } 169 170 uint32_t Symbol::GetSiblingIndex() const { 171 return m_size_is_sibling ? m_addr_range.GetByteSize() : UINT32_MAX; 172 } 173 174 bool Symbol::IsTrampoline() const { return m_type == eSymbolTypeTrampoline; } 175 176 bool Symbol::IsIndirect() const { return m_type == eSymbolTypeResolver; } 177 178 void Symbol::GetDescription(Stream *s, lldb::DescriptionLevel level, 179 Target *target) const { 180 s->Printf("id = {0x%8.8x}", m_uid); 181 182 if (m_addr_range.GetBaseAddress().GetSection()) { 183 if (ValueIsAddress()) { 184 const lldb::addr_t byte_size = GetByteSize(); 185 if (byte_size > 0) { 186 s->PutCString(", range = "); 187 m_addr_range.Dump(s, target, Address::DumpStyleLoadAddress, 188 Address::DumpStyleFileAddress); 189 } else { 190 s->PutCString(", address = "); 191 m_addr_range.GetBaseAddress().Dump(s, target, 192 Address::DumpStyleLoadAddress, 193 Address::DumpStyleFileAddress); 194 } 195 } else 196 s->Printf(", value = 0x%16.16" PRIx64, 197 m_addr_range.GetBaseAddress().GetOffset()); 198 } else { 199 if (m_size_is_sibling) 200 s->Printf(", sibling = %5" PRIu64, 201 m_addr_range.GetBaseAddress().GetOffset()); 202 else 203 s->Printf(", value = 0x%16.16" PRIx64, 204 m_addr_range.GetBaseAddress().GetOffset()); 205 } 206 ConstString demangled = m_mangled.GetDemangledName(GetLanguage()); 207 if (demangled) 208 s->Printf(", name=\"%s\"", demangled.AsCString()); 209 if (m_mangled.GetMangledName()) 210 s->Printf(", mangled=\"%s\"", m_mangled.GetMangledName().AsCString()); 211 } 212 213 void Symbol::Dump(Stream *s, Target *target, uint32_t index) const { 214 s->Printf("[%5u] %6u %c%c%c %-15s ", index, GetID(), m_is_debug ? 'D' : ' ', 215 m_is_synthetic ? 'S' : ' ', m_is_external ? 'X' : ' ', 216 GetTypeAsString()); 217 218 // Make sure the size of the symbol is up to date before dumping 219 GetByteSize(); 220 221 ConstString name = m_mangled.GetName(GetLanguage()); 222 if (ValueIsAddress()) { 223 if (!m_addr_range.GetBaseAddress().Dump(s, nullptr, 224 Address::DumpStyleFileAddress)) 225 s->Printf("%*s", 18, ""); 226 227 s->PutChar(' '); 228 229 if (!m_addr_range.GetBaseAddress().Dump(s, target, 230 Address::DumpStyleLoadAddress)) 231 s->Printf("%*s", 18, ""); 232 233 const char *format = m_size_is_sibling ? " Sibling -> [%5llu] 0x%8.8x %s\n" 234 : " 0x%16.16" PRIx64 " 0x%8.8x %s\n"; 235 s->Printf(format, GetByteSize(), m_flags, name.AsCString("")); 236 } else if (m_type == eSymbolTypeReExported) { 237 s->Printf( 238 " 0x%8.8x %s", 239 m_flags, name.AsCString("")); 240 241 ConstString reexport_name = GetReExportedSymbolName(); 242 intptr_t shlib = m_addr_range.GetByteSize(); 243 if (shlib) 244 s->Printf(" -> %s`%s\n", (const char *)shlib, reexport_name.GetCString()); 245 else 246 s->Printf(" -> %s\n", reexport_name.GetCString()); 247 } else { 248 const char *format = 249 m_size_is_sibling 250 ? "0x%16.16" PRIx64 251 " Sibling -> [%5llu] 0x%8.8x %s\n" 252 : "0x%16.16" PRIx64 " 0x%16.16" PRIx64 253 " 0x%8.8x %s\n"; 254 s->Printf(format, m_addr_range.GetBaseAddress().GetOffset(), GetByteSize(), 255 m_flags, name.AsCString("")); 256 } 257 } 258 259 uint32_t Symbol::GetPrologueByteSize() { 260 if (m_type == eSymbolTypeCode || m_type == eSymbolTypeResolver) { 261 if (!m_type_data_resolved) { 262 m_type_data_resolved = true; 263 264 const Address &base_address = m_addr_range.GetBaseAddress(); 265 Function *function = base_address.CalculateSymbolContextFunction(); 266 if (function) { 267 // Functions have line entries which can also potentially have end of 268 // prologue information. So if this symbol points to a function, use 269 // the prologue information from there. 270 m_type_data = function->GetPrologueByteSize(); 271 } else { 272 ModuleSP module_sp(base_address.GetModule()); 273 SymbolContext sc; 274 if (module_sp) { 275 uint32_t resolved_flags = module_sp->ResolveSymbolContextForAddress( 276 base_address, eSymbolContextLineEntry, sc); 277 if (resolved_flags & eSymbolContextLineEntry) { 278 // Default to the end of the first line entry. 279 m_type_data = sc.line_entry.range.GetByteSize(); 280 281 // Set address for next line. 282 Address addr(base_address); 283 addr.Slide(m_type_data); 284 285 // Check the first few instructions and look for one that has a 286 // line number that is different than the first entry. This is also 287 // done in Function::GetPrologueByteSize(). 288 uint16_t total_offset = m_type_data; 289 for (int idx = 0; idx < 6; ++idx) { 290 SymbolContext sc_temp; 291 resolved_flags = module_sp->ResolveSymbolContextForAddress( 292 addr, eSymbolContextLineEntry, sc_temp); 293 // Make sure we got line number information... 294 if (!(resolved_flags & eSymbolContextLineEntry)) 295 break; 296 297 // If this line number is different than our first one, use it 298 // and we're done. 299 if (sc_temp.line_entry.line != sc.line_entry.line) { 300 m_type_data = total_offset; 301 break; 302 } 303 304 // Slide addr up to the next line address. 305 addr.Slide(sc_temp.line_entry.range.GetByteSize()); 306 total_offset += sc_temp.line_entry.range.GetByteSize(); 307 // If we've gone too far, bail out. 308 if (total_offset >= m_addr_range.GetByteSize()) 309 break; 310 } 311 312 // Sanity check - this may be a function in the middle of code that 313 // has debug information, but not for this symbol. So the line 314 // entries surrounding us won't lie inside our function. In that 315 // case, the line entry will be bigger than we are, so we do that 316 // quick check and if that is true, we just return 0. 317 if (m_type_data >= m_addr_range.GetByteSize()) 318 m_type_data = 0; 319 } else { 320 // TODO: expose something in Process to figure out the 321 // size of a function prologue. 322 m_type_data = 0; 323 } 324 } 325 } 326 } 327 return m_type_data; 328 } 329 return 0; 330 } 331 332 bool Symbol::Compare(ConstString name, SymbolType type) const { 333 if (type == eSymbolTypeAny || m_type == type) 334 return m_mangled.GetMangledName() == name || 335 m_mangled.GetDemangledName(GetLanguage()) == name; 336 return false; 337 } 338 339 #define ENUM_TO_CSTRING(x) \ 340 case eSymbolType##x: \ 341 return #x; 342 343 const char *Symbol::GetTypeAsString() const { 344 switch (m_type) { 345 ENUM_TO_CSTRING(Invalid); 346 ENUM_TO_CSTRING(Absolute); 347 ENUM_TO_CSTRING(Code); 348 ENUM_TO_CSTRING(Resolver); 349 ENUM_TO_CSTRING(Data); 350 ENUM_TO_CSTRING(Trampoline); 351 ENUM_TO_CSTRING(Runtime); 352 ENUM_TO_CSTRING(Exception); 353 ENUM_TO_CSTRING(SourceFile); 354 ENUM_TO_CSTRING(HeaderFile); 355 ENUM_TO_CSTRING(ObjectFile); 356 ENUM_TO_CSTRING(CommonBlock); 357 ENUM_TO_CSTRING(Block); 358 ENUM_TO_CSTRING(Local); 359 ENUM_TO_CSTRING(Param); 360 ENUM_TO_CSTRING(Variable); 361 ENUM_TO_CSTRING(VariableType); 362 ENUM_TO_CSTRING(LineEntry); 363 ENUM_TO_CSTRING(LineHeader); 364 ENUM_TO_CSTRING(ScopeBegin); 365 ENUM_TO_CSTRING(ScopeEnd); 366 ENUM_TO_CSTRING(Additional); 367 ENUM_TO_CSTRING(Compiler); 368 ENUM_TO_CSTRING(Instrumentation); 369 ENUM_TO_CSTRING(Undefined); 370 ENUM_TO_CSTRING(ObjCClass); 371 ENUM_TO_CSTRING(ObjCMetaClass); 372 ENUM_TO_CSTRING(ObjCIVar); 373 ENUM_TO_CSTRING(ReExported); 374 default: 375 break; 376 } 377 return "<unknown SymbolType>"; 378 } 379 380 void Symbol::CalculateSymbolContext(SymbolContext *sc) { 381 // Symbols can reconstruct the symbol and the module in the symbol context 382 sc->symbol = this; 383 if (ValueIsAddress()) 384 sc->module_sp = GetAddressRef().GetModule(); 385 else 386 sc->module_sp.reset(); 387 } 388 389 ModuleSP Symbol::CalculateSymbolContextModule() { 390 if (ValueIsAddress()) 391 return GetAddressRef().GetModule(); 392 return ModuleSP(); 393 } 394 395 Symbol *Symbol::CalculateSymbolContextSymbol() { return this; } 396 397 void Symbol::DumpSymbolContext(Stream *s) { 398 bool dumped_module = false; 399 if (ValueIsAddress()) { 400 ModuleSP module_sp(GetAddressRef().GetModule()); 401 if (module_sp) { 402 dumped_module = true; 403 module_sp->DumpSymbolContext(s); 404 } 405 } 406 if (dumped_module) 407 s->PutCString(", "); 408 409 s->Printf("Symbol{0x%8.8x}", GetID()); 410 } 411 412 lldb::addr_t Symbol::GetByteSize() const { return m_addr_range.GetByteSize(); } 413 414 Symbol *Symbol::ResolveReExportedSymbolInModuleSpec( 415 Target &target, ConstString &reexport_name, ModuleSpec &module_spec, 416 ModuleList &seen_modules) const { 417 ModuleSP module_sp; 418 if (module_spec.GetFileSpec()) { 419 // Try searching for the module file spec first using the full path 420 module_sp = target.GetImages().FindFirstModule(module_spec); 421 if (!module_sp) { 422 // Next try and find the module by basename in case environment variables 423 // or other runtime trickery causes shared libraries to be loaded from 424 // alternate paths 425 module_spec.GetFileSpec().GetDirectory().Clear(); 426 module_sp = target.GetImages().FindFirstModule(module_spec); 427 } 428 } 429 430 if (module_sp) { 431 // There should not be cycles in the reexport list, but we don't want to 432 // crash if there are so make sure we haven't seen this before: 433 if (!seen_modules.AppendIfNeeded(module_sp)) 434 return nullptr; 435 436 lldb_private::SymbolContextList sc_list; 437 module_sp->FindSymbolsWithNameAndType(reexport_name, eSymbolTypeAny, 438 sc_list); 439 const size_t num_scs = sc_list.GetSize(); 440 if (num_scs > 0) { 441 for (size_t i = 0; i < num_scs; ++i) { 442 lldb_private::SymbolContext sc; 443 if (sc_list.GetContextAtIndex(i, sc)) { 444 if (sc.symbol->IsExternal()) 445 return sc.symbol; 446 } 447 } 448 } 449 // If we didn't find the symbol in this module, it may be because this 450 // module re-exports some whole other library. We have to search those as 451 // well: 452 seen_modules.Append(module_sp); 453 454 FileSpecList reexported_libraries = 455 module_sp->GetObjectFile()->GetReExportedLibraries(); 456 size_t num_reexported_libraries = reexported_libraries.GetSize(); 457 for (size_t idx = 0; idx < num_reexported_libraries; idx++) { 458 ModuleSpec reexported_module_spec; 459 reexported_module_spec.GetFileSpec() = 460 reexported_libraries.GetFileSpecAtIndex(idx); 461 Symbol *result_symbol = ResolveReExportedSymbolInModuleSpec( 462 target, reexport_name, reexported_module_spec, seen_modules); 463 if (result_symbol) 464 return result_symbol; 465 } 466 } 467 return nullptr; 468 } 469 470 Symbol *Symbol::ResolveReExportedSymbol(Target &target) const { 471 ConstString reexport_name(GetReExportedSymbolName()); 472 if (reexport_name) { 473 ModuleSpec module_spec; 474 ModuleList seen_modules; 475 module_spec.GetFileSpec() = GetReExportedSymbolSharedLibrary(); 476 if (module_spec.GetFileSpec()) { 477 return ResolveReExportedSymbolInModuleSpec(target, reexport_name, 478 module_spec, seen_modules); 479 } 480 } 481 return nullptr; 482 } 483 484 lldb::addr_t Symbol::GetFileAddress() const { 485 if (ValueIsAddress()) 486 return GetAddressRef().GetFileAddress(); 487 else 488 return LLDB_INVALID_ADDRESS; 489 } 490 491 lldb::addr_t Symbol::GetLoadAddress(Target *target) const { 492 if (ValueIsAddress()) 493 return GetAddressRef().GetLoadAddress(target); 494 else 495 return LLDB_INVALID_ADDRESS; 496 } 497 498 ConstString Symbol::GetName() const { return m_mangled.GetName(GetLanguage()); } 499 500 ConstString Symbol::GetNameNoArguments() const { 501 return m_mangled.GetName(GetLanguage(), 502 Mangled::ePreferDemangledWithoutArguments); 503 } 504 505 lldb::addr_t Symbol::ResolveCallableAddress(Target &target) const { 506 if (GetType() == lldb::eSymbolTypeUndefined) 507 return LLDB_INVALID_ADDRESS; 508 509 Address func_so_addr; 510 511 bool is_indirect = IsIndirect(); 512 if (GetType() == eSymbolTypeReExported) { 513 Symbol *reexported_symbol = ResolveReExportedSymbol(target); 514 if (reexported_symbol) { 515 func_so_addr = reexported_symbol->GetAddress(); 516 is_indirect = reexported_symbol->IsIndirect(); 517 } 518 } else { 519 func_so_addr = GetAddress(); 520 is_indirect = IsIndirect(); 521 } 522 523 if (func_so_addr.IsValid()) { 524 if (!target.GetProcessSP() && is_indirect) { 525 // can't resolve indirect symbols without calling a function... 526 return LLDB_INVALID_ADDRESS; 527 } 528 529 lldb::addr_t load_addr = 530 func_so_addr.GetCallableLoadAddress(&target, is_indirect); 531 532 if (load_addr != LLDB_INVALID_ADDRESS) { 533 return load_addr; 534 } 535 } 536 537 return LLDB_INVALID_ADDRESS; 538 } 539 540 lldb::DisassemblerSP Symbol::GetInstructions(const ExecutionContext &exe_ctx, 541 const char *flavor, 542 bool prefer_file_cache) { 543 ModuleSP module_sp(m_addr_range.GetBaseAddress().GetModule()); 544 if (module_sp) { 545 const bool prefer_file_cache = false; 546 return Disassembler::DisassembleRange(module_sp->GetArchitecture(), nullptr, 547 flavor, exe_ctx, m_addr_range, 548 prefer_file_cache); 549 } 550 return lldb::DisassemblerSP(); 551 } 552 553 bool Symbol::GetDisassembly(const ExecutionContext &exe_ctx, const char *flavor, 554 bool prefer_file_cache, Stream &strm) { 555 lldb::DisassemblerSP disassembler_sp = 556 GetInstructions(exe_ctx, flavor, prefer_file_cache); 557 if (disassembler_sp) { 558 const bool show_address = true; 559 const bool show_bytes = false; 560 disassembler_sp->GetInstructionList().Dump(&strm, show_address, show_bytes, 561 &exe_ctx); 562 return true; 563 } 564 return false; 565 } 566 567 bool Symbol::ContainsFileAddress(lldb::addr_t file_addr) const { 568 return m_addr_range.ContainsFileAddress(file_addr); 569 } 570