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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 | /* * Copyright (c) 2021 Apple Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #include "MemoryBuffer.h" #include <algorithm> #include <sys/types.h> #include <assert.h> #include <limits.h> #include <stdlib.h> #include <string.h> #if BUILDING_MACHO_WRITER #include <mach-o/loader.h> #include <mach-o/nlist.h> #include <mach-o/stab.h> #include "Algorithm.h" #endif // BUILDING_MACHO_WRITER #include "Symbol.h" #include "NListSymbolTable.h" #include "Misc.h" namespace mach_o { // // MARK: --- NListSymbolTable inspection methods --- // NListSymbolTable::NListSymbolTable(uint32_t preferredLoadAddress, const struct nlist* symbols, uint32_t nlistCount, const char* stringPool, uint32_t stringPoolSize, uint32_t localsCount, uint32_t globalsCount, uint32_t undefsCount) : _preferredLoadAddress(preferredLoadAddress), _stringPool(stringPool), _nlist32(symbols), _nlist64(nullptr), _stringPoolSize(stringPoolSize), _nlistCount(nlistCount), _localsCount(localsCount), _globalsCount(globalsCount), _undefsCount(undefsCount) { } NListSymbolTable::NListSymbolTable(uint64_t preferredLoadAddress, const struct nlist_64* symbols, uint32_t nlistCount, const char* stringPool, uint32_t stringPoolSize, uint32_t localsCount, uint32_t globalsCount, uint32_t undefsCount) : _preferredLoadAddress(preferredLoadAddress), _stringPool(stringPool), _nlist32(nullptr), _nlist64(symbols), _stringPoolSize(stringPoolSize), _nlistCount(nlistCount), _localsCount(localsCount), _globalsCount(globalsCount), _undefsCount(undefsCount) { } Error NListSymbolTable::valid(uint64_t maxVmOffset) const { // FIXME return Error::none(); } int NListSymbolTable::libOrdinalFromDesc(uint16_t n_desc) const { // -flat_namespace is always flat lookup // if ( (this->flags & MH_TWOLEVEL) == 0 ) // return BIND_SPECIAL_DYLIB_FLAT_LOOKUP; // extract byte from undefined symbol entry int libIndex = GET_LIBRARY_ORDINAL(n_desc); switch ( libIndex ) { case SELF_LIBRARY_ORDINAL: return BIND_SPECIAL_DYLIB_SELF; case DYNAMIC_LOOKUP_ORDINAL: return BIND_SPECIAL_DYLIB_FLAT_LOOKUP; case EXECUTABLE_ORDINAL: return BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE; } return libIndex; } Symbol NListSymbolTable::symbolFromNList(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc) const { bool dontDeadStrip = (n_desc & N_NO_DEAD_STRIP); bool cold = (n_desc & N_COLD_FUNC); switch ( n_type & N_TYPE ) { case N_UNDF: if ( n_value == 0 ) return Symbol::makeUndefined(symbolName, libOrdinalFromDesc(n_desc), ((n_desc & N_WEAK_REF) != 0)); else if ( n_type & N_PEXT ) return Symbol::makeHiddenTentativeDef(symbolName, n_value, GET_COMM_ALIGN(n_desc), dontDeadStrip, cold); else return Symbol::makeTentativeDef(symbolName, n_value, GET_COMM_ALIGN(n_desc), dontDeadStrip, cold); case N_ABS: if ( n_type & N_EXT ) return Symbol::makeAbsoluteExport(symbolName, n_value, dontDeadStrip); else return Symbol::makeAbsoluteLocal(symbolName, n_value, dontDeadStrip); case N_INDR: { const char* importName = symbolName; if ( n_value < _stringPoolSize ) importName = _stringPool + n_value; if ( (n_type & N_EXT) == 0 ) { if ( (n_type & N_PEXT )) return Symbol::makeReExport(symbolName, 0, importName, Symbol::Scope::wasLinkageUnit); else return Symbol::makeReExport(symbolName, 0, importName, Symbol::Scope::translationUnit); } else if ( (n_type & N_PEXT ) ) return Symbol::makeReExport(symbolName, 0, importName, Symbol::Scope::linkageUnit); else return Symbol::makeReExport(symbolName, 0, importName, Symbol::Scope::global); } case N_SECT: { if ( (n_type & N_EXT) == 0 ) { if ( n_desc & N_ALT_ENTRY ) return Symbol::makeAltEntry(symbolName, n_value - _preferredLoadAddress, n_sect, Symbol::Scope::translationUnit, dontDeadStrip, cold, (n_desc & N_WEAK_DEF) != 0); else if ( n_type & N_PEXT ) { if ( n_desc & N_WEAK_DEF ) return Symbol::makeWeakDefWasPrivateExtern(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); else return Symbol::makeRegularWasPrivateExtern(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); } else return Symbol::makeRegularLocal(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); } else if ( n_type & N_PEXT ) { if ( n_desc & N_ALT_ENTRY ) return Symbol::makeAltEntry(symbolName, n_value - _preferredLoadAddress, n_sect, Symbol::Scope::linkageUnit, dontDeadStrip, cold, (n_desc & N_WEAK_DEF) != 0); else if ( n_desc & N_WEAK_DEF ) return Symbol::makeWeakDefHidden(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); else return Symbol::makeRegularHidden(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); } else if ( n_desc & N_ALT_ENTRY ) { return Symbol::makeAltEntry(symbolName, n_value - _preferredLoadAddress, n_sect, Symbol::Scope::global, dontDeadStrip, cold, (n_desc & N_WEAK_DEF) != 0); } else if ( (n_desc & (N_WEAK_DEF|N_WEAK_REF)) == (N_WEAK_DEF|N_WEAK_REF) ) { return Symbol::makeWeakDefAutoHide(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); } else if ( n_desc & N_WEAK_DEF ) { return Symbol::makeWeakDefExport(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold); } else if ( n_desc & N_SYMBOL_RESOLVER ) { return Symbol::makeDynamicResolver(symbolName, n_sect, 0, n_value - _preferredLoadAddress); } else { bool neverStrip = (n_desc & REFERENCED_DYNAMICALLY); return Symbol::makeRegularExport(symbolName, n_value - _preferredLoadAddress, n_sect, dontDeadStrip, cold, neverStrip); } } } return Symbol(); } void NListSymbolTable::forEachExportedSymbol(void (^callback)(const Symbol& symbol, uint32_t symbolIndex, bool& stop)) const { if ( (_localsCount == 0) && (_globalsCount == 0) && (_undefsCount == 0) && (_nlistCount != 0) ) { // if no LC_DYSYMTAB, need to scan whole table and selectively find global symbols forEachSymbol(^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { uint8_t type = n_type & N_TYPE; if ( (n_type & N_EXT) && ((type == N_SECT) || (type == N_ABS) || (type == N_INDR)) && ((n_type & N_STAB) == 0)) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } else { uint32_t globalsStartIndex = _localsCount; forEachSymbol(globalsStartIndex, _globalsCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { uint8_t type = n_type & N_TYPE; if ( (n_type & N_EXT) && ((type == N_SECT) || (type == N_ABS) || (type == N_INDR)) && ((n_type & N_STAB) == 0)) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } } void NListSymbolTable::forEachDefinedSymbol(void (^callback)(const Symbol& symbol, uint32_t symbolIndex, bool& stop)) const { if ( (_localsCount == 0) && (_globalsCount == 0) && (_undefsCount == 0) && (_nlistCount != 0) ) { // if no LC_DYSYMTAB, need to scan whole table and selectively find defined symbols forEachSymbol(0, _nlistCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { uint8_t type = n_type & N_TYPE; if ( ((type == N_SECT) || (type == N_ABS)) && ((n_type & N_STAB) == 0) ) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } else { forEachSymbol(0, _localsCount+_globalsCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { uint8_t type = n_type & N_TYPE; if ( ((type == N_SECT) || (type == N_ABS)) && ((n_type & N_STAB) == 0) ) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } } void NListSymbolTable::forEachSymbol(void (^callback)(const Symbol& symbol, uint32_t symbolIndex, bool& stop)) const { forEachSymbol(0, _nlistCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { if ( (n_type & N_STAB) == 0 ) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } void NListSymbolTable::forEachSymbol(void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop)) const { forEachSymbol(0, _nlistCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { callback(symbolName, n_value, n_type, n_sect, n_desc, symbolIndex, stop); }); } bool NListSymbolTable::forEachSymbol(uint32_t startSymbolIndex, uint32_t symbolCount, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop)) const { bool stop = false; for (uint32_t i = 0; (i < symbolCount) && !stop; ++i ) { if ( _nlist64 != nullptr ) { const struct nlist_64& sym = _nlist64[startSymbolIndex + i]; if ( sym.n_un.n_strx > _stringPoolSize ) continue; callback(&_stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, startSymbolIndex + i, stop); } else { const struct nlist& sym = _nlist32[startSymbolIndex + i]; if ( sym.n_un.n_strx > _stringPoolSize ) continue; callback(&_stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, startSymbolIndex + i, stop); } } return stop; } bool NListSymbolTable::symbolAtIndex(uint32_t symbolIndex, Symbol& symbol) const { if ( symbolIndex >= _nlistCount ) return false; if ( _nlist64 ) { const struct nlist_64& sym = _nlist64[symbolIndex]; if ( sym.n_un.n_strx > _stringPoolSize ) return false; symbol = symbolFromNList(&_stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc); return true; } if ( _nlist32 ) { const struct nlist& sym = _nlist32[symbolIndex]; if ( sym.n_un.n_strx > _stringPoolSize ) return false; symbol = symbolFromNList(&_stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc); return true; } return false; } bool NListSymbolTable::findClosestDefinedSymbol(uint64_t unslidAddr, Symbol& sym) const { __block uint64_t bestNValue = 0; __block const char* bestName = nullptr; __block uint16_t bestNDesc = 0; __block uint8_t bestNType = 0; __block uint8_t bestNSect = 0; auto nlistChecker = ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { if ( ((n_type & N_TYPE) == N_SECT) && ((n_type & N_STAB) == 0) ) { if ( (bestNValue < n_value) && (n_value <= unslidAddr) ) { bestNValue = n_value; bestNDesc = n_desc; bestNType = n_type; bestNSect = n_sect; bestName = symbolName; } } }; // first walk all global symbols, then all locals, recording closet symbol <= to target const uint32_t globalsStartIndex = _localsCount; const uint32_t localsStartIndex = 0; if ( !this->forEachSymbol(globalsStartIndex, _globalsCount, nlistChecker) ) this->forEachSymbol(localsStartIndex, _localsCount, nlistChecker); if ( bestName != nullptr ) { sym = symbolFromNList(bestName, bestNValue, bestNType, bestNSect, bestNDesc); return true; } return false; } uint32_t NListSymbolTable::undefsStartIndex() const { if ( (_localsCount == 0) && (_globalsCount == 0) && (_undefsCount == 0) && (_nlistCount != 0) ) return 0; // no LC_DYSYMTAB, any symbol can be undefined return _localsCount+_globalsCount; } void NListSymbolTable::forEachUndefinedSymbol(void (^callback)(const Symbol& symbol, uint32_t symbolIndex, bool& stop)) const { if ( (_localsCount == 0) && (_globalsCount == 0) && (_undefsCount == 0) && (_nlistCount != 0) ) { // if no LC_DYSYMTAB, need to scan whole table and selectively find undefined symbols forEachSymbol(0, _nlistCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { if ( ((n_type & N_TYPE) == N_UNDF) && ((n_type & N_STAB) == 0) ) callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } else { uint32_t undefinesStartIndex = _localsCount+_globalsCount; forEachSymbol(undefinesStartIndex, _undefsCount, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { callback(symbolFromNList(symbolName, n_value, n_type, n_sect, n_desc), symbolIndex, stop); }); } } uint64_t NListSymbolTable::nValueFromSymbolIndex(uint32_t symbolIndex) const { assert(symbolIndex < _nlistCount); if ( _nlist64 != nullptr ) return _nlist64[symbolIndex].n_value; else return _nlist32[symbolIndex].n_value; } // // MARK: --- NListSymbolTable building methods --- // #if BUILDING_MACHO_WRITER void NListSymbolTable::forEachDebugNote(bool freeFileInfo, void (^callback)(const DebugNote& note, bool& stop)) const { __block CString currentSrcDir = nullptr; __block CString currentSrcName = nullptr; __block CString currentObjPath = nullptr; __block uint32_t currentObjModTime = 0; __block uint32_t currentObjSubType = 0; __block CString currentOriginlibPath = nullptr; __block DebugNote currentNote; // if no LC_DYSYMTAB, need to scan whole table and selectively find stab symbols uint32_t count = _localsCount; if ( (_localsCount == 0) && (_globalsCount == 0) && (_undefsCount == 0) && (_nlistCount != 0) ) count = _nlistCount; forEachSymbol(0, count, ^(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, uint32_t symbolIndex, bool& stop) { if ( (n_type & N_STAB) == 0 ) return; switch ( n_type ) { case N_SO: if ( n_sect == 1 ) { // end of file // ld64 wrote extra "end SO" at start of debug notes, we need to skip over that if ( !currentSrcName.empty() ) { // build temp DebugNoteFileInfo just for use during the callback const DebugNoteFileInfo* fileInfo = DebugNoteFileInfo::make(currentSrcDir, currentSrcName, currentObjPath, currentObjModTime, currentObjSubType, "", currentOriginlibPath); currentNote.fileInfo = fileInfo; callback(currentNote, stop); currentNote.fileInfo = nullptr; currentSrcDir = nullptr; currentSrcName = nullptr; currentObjPath = nullptr; currentObjModTime = 0; currentObjSubType = 0; currentOriginlibPath = nullptr; if ( freeFileInfo ) free((void*)fileInfo); } } else { currentNote.items.clear(); size_t len = strlen(symbolName); if ( (len > 1) && (symbolName[len-1] == '/') ) currentSrcDir = symbolName; else currentSrcName = symbolName; } break; case N_OSO: currentObjPath = symbolName; currentObjModTime = (uint32_t)n_value; currentObjSubType = n_sect; break; case N_LIB: currentOriginlibPath = symbolName; break; case N_BNSYM: currentNote.items.push_back({n_value, 0, nullptr, N_FUN, n_sect}); break; case N_FUN: if ( n_sect != 0 ) currentNote.items.back().name = symbolName; else currentNote.items.back().size = n_value; break; case N_ENSYM: break; case N_STSYM: currentNote.items.push_back({n_value, 0, symbolName, N_STSYM, n_sect}); break; case N_GSYM: currentNote.items.push_back({0, 0, symbolName, N_GSYM, 0}); break; default: // ignore other stabs break; } }); } uint32_t NListSymbolTable::countDebugNoteNLists(std::span<const DebugBuilderNote> debugNotes) { uint32_t debugStabNlists=0; bool startedSO=false; for ( const DebugBuilderNote& note : debugNotes ) { if ( note.fileInfo->srcDir().empty() && note.fileInfo->srcName().empty() ) { debugStabNlists += 1; } else { if ( !startedSO ) { startedSO = true; debugStabNlists += 1; } debugStabNlists += 4; if ( note.fileInfo->hasOriginLibInfo() ) debugStabNlists += 1; for ( const DebugBuilderNoteItem& item : note.items ) { if ( item.type == N_FUN ) debugStabNlists += 4; else debugStabNlists += 1; } } } return debugStabNlists; } template <typename T> void NListSymbolTable::addStabsFromDebugNotes(std::span<const DebugBuilderNote> debugNotes, bool zeroModTimes, NListBuffer& nlists) { typedef __typeof(T::n_value) V; bool startedSOs = false; for (const DebugBuilderNote& note : debugNotes) { uint32_t mtime = (zeroModTimes ? 0 : note.fileInfo->objModTime()); if ( note.srcDirPoolOffset == 0 && note.srcNamePoolOffset == 0 ) { nlists.add(T{{note.objPathPoolOffset}, N_AST, 0, 0, (V)mtime}); } else { if ( !startedSOs ) nlists.add(T{{1}, N_SO, 1, 0, 0}); // match ld64 which always started debug notes with an "end SO" // Put this before the other N_SO's. We can't put it right before the N_OSO as lldb expects the N_OSO // to be immediately preceded by the N_SO if ( note.originLibPathPoolOffset != 0 ) { nlists.add(T{{note.originLibPathPoolOffset}, N_LIB, 0, 0, 0}); } startedSOs = true; nlists.add(T{{note.srcDirPoolOffset}, N_SO, 0, 0, 0}); nlists.add(T{{note.srcNamePoolOffset}, N_SO, 0, 0, 0}); nlists.add(T{{note.objPathPoolOffset}, N_OSO, note.fileInfo->objSubType(), 1, (V)mtime}); for (const DebugBuilderNoteItem& item : note.items) { uint32_t stringPoolOffset = item.stringPoolOffset; switch ( item.type ) { case N_FUN: // for functions, we use four symbols to record the name, address, size, and sectNum nlists.add(T{{1}, N_BNSYM, item.sectNum, 0, (V)item.addr}); nlists.add(T{{stringPoolOffset}, N_FUN, item.sectNum, 0, (V)item.addr}); nlists.add(T{{1}, N_FUN, 0, 0, (V)item.size}); nlists.add(T{{1}, N_ENSYM, item.sectNum, 0, (V)item.addr}); break; case N_STSYM: // for static variables, we record the name, address, and sectNum nlists.add(T{{stringPoolOffset}, N_STSYM, item.sectNum, 0, (V)item.addr}); break; case N_GSYM: // for global variables, we record just the name nlists.add(T{{stringPoolOffset}, N_GSYM, 0, 0, 0}); break; default: assert(false && "invalid debug note item"); break; } } nlists.add(T{{1}, N_SO, 1, 0, 0}); } } } /*! * @class NListStringPoolBuffer * * @abstract * Simple NList string pool buffer, used in unit-tests. */ struct NListStringPoolBuffer { std::vector<char> buffer; uint32_t pos = 0; NListStringPoolBuffer() { add(' '); add('\0'); } NListStringPoolBuffer(const NListStringPoolBuffer&) = delete; NListStringPoolBuffer(NListStringPoolBuffer&&) = default; NListStringPoolBuffer& operator=(const NListStringPoolBuffer&) = delete; NListStringPoolBuffer& operator=(NListStringPoolBuffer&&) = default; uint32_t add(CString str); uint32_t add(std::span<const char> bytes); uint32_t add(char ch); uint32_t size() { return pos; } char* data() { return buffer.data(); } void finalize(bool is64) { uint32_t pointerSize = is64 ? 8 : 4; while ( size() % pointerSize ) add('\0'); } std::pair<uint32_t, char*> reserve(size_t); }; NListSymbolTable::SymbolPartition::SymbolPartition(std::span<const Symbol> symbols, bool objectFile) { for (const Symbol& symbol : symbols) { int libOrdinal; bool weakImport; uint64_t size; uint8_t p2Align; if ( symbol.isUndefined(libOrdinal, weakImport) || symbol.isTentativeDef(size, p2Align) ) undefs.push_back(symbol); else if ( symbol.scope() == Symbol::Scope::global ) globals.push_back(symbol); else if ( (symbol.scope() == Symbol::Scope::linkageUnit) && objectFile ) globals.push_back(symbol); // in .o files hidden symbols are in globals range else if ( (symbol.scope() == Symbol::Scope::autoHide) && objectFile ) globals.push_back(symbol); // in .o files hidden symbols are in globals range else locals.push_back(symbol); } // for historical binary search reasons, globals are sorted by name std::sort(globals.begin(), globals.end(), [&](const Symbol& a, const Symbol& b) { return a.name() < b.name(); }); // undefs are sorted by name std::sort(undefs.begin(), undefs.end(), [&](const Symbol& a, const Symbol& b) { return a.name() < b.name(); }); // locals are already sorted by their position in their section. We don't need to sort them again } NListSymbolTable::NListSymbolTable(std::span<const Symbol> symbols, uint64_t prefLoadAddr, bool is64, std::span<DebugBuilderNote> debugNotes, bool zeroModTimes, bool objectFile) : NListSymbolTable(SymbolPartition(symbols, objectFile), debugNotes, prefLoadAddr, is64, zeroModTimes) {} NListSymbolTable::NListSymbolTable(const SymbolPartition& partition, std::span<DebugBuilderNote> debugNotes, uint64_t prefLoadAddr, bool is64, bool zeroModTimes) : NListSymbolTable(partition.globals, partition.undefs, partition.locals, debugNotes, prefLoadAddr, is64, zeroModTimes) {} NListSymbolTable::NListSymbolTable(std::span<const Symbol> globals, std::span<const Symbol> undefs, std::span<const Symbol> locals, std::span<DebugBuilderNote> debugNotes, uint64_t prefLoadAddr, bool is64, bool zeroModTimes) { uint32_t numDebugNlist = countDebugNoteNLists(debugNotes); size_t nlistSize = (locals.size() + globals.size() + undefs.size() + numDebugNlist) * (is64 ? sizeof(nlist_64) : sizeof(struct nlist)); NListStringPoolBuffer stringPoolBuffer; size_t strxAllCount = globals.size() * 2 + locals.size() + undefs.size(); std::vector<uint32_t> strxAll(strxAllCount); std::span<uint32_t> globalsStrx = std::span(strxAll).subspan(0, globals.size()); std::span<uint32_t> reexportsStrx = std::span(globalsStrx.end().base(), globals.size()); std::span<uint32_t> undefsStrx = std::span(reexportsStrx.end().base(), undefs.size()); std::span<uint32_t> localsStrx = std::span(undefsStrx.end().base(), locals.size()); for ( size_t i = 0; i < globals.size(); ++i ) { const Symbol& s = globals[i]; globalsStrx[i] = stringPoolBuffer.add(s.name()); int32_t ordinal; const char* importName=nullptr; if ( s.isReExport(ordinal, importName) ) reexportsStrx[i] = stringPoolBuffer.add(s.name()); } for ( size_t i = 0; i < undefs.size(); ++i ) { const Symbol& s = undefs[i]; undefsStrx[i] = stringPoolBuffer.add(s.name()); } for ( size_t i = 0; i < locals.size(); ++i ) { const Symbol& s = locals[i]; localsStrx[i] = stringPoolBuffer.add(s.name()); } for ( DebugBuilderNote& debugNote : debugNotes ) { if ( CString srcDir = debugNote.fileInfo->srcDir(); !srcDir.empty() ) debugNote.srcDirPoolOffset = stringPoolBuffer.add(srcDir); if ( CString srcName = debugNote.fileInfo->srcName(); !srcName.empty() ) debugNote.srcNamePoolOffset = stringPoolBuffer.add(srcName); if ( CString originLibPath = debugNote.fileInfo->originLibPath(); !originLibPath.empty() ) debugNote.originLibPathPoolOffset=stringPoolBuffer.add(originLibPath); if ( CString objPath = debugNote.fileInfo->objPath(); !objPath.empty() ) debugNote.objPathPoolOffset=stringPoolBuffer.add(objPath); for ( DebugBuilderNoteItem& item : debugNote.items ) { item.stringPoolOffset=stringPoolBuffer.add(item.name); } } stringPoolBuffer.finalize(is64); *this = NListSymbolTable(NListLayout{ globals, globalsStrx, reexportsStrx, undefs, undefsStrx, locals, localsStrx, debugNotes, numDebugNlist }, NListBuffer(nlistSize), std::move(stringPoolBuffer.buffer), prefLoadAddr, is64, zeroModTimes); } NListSymbolTable::NListSymbolTable(NListLayout layout, std::span<uint8_t> nlistBuffer, uint64_t prefLoadAddr, bool is64, bool zeroModTimes): NListSymbolTable(layout, NListBuffer(nlistBuffer), {}, prefLoadAddr, is64, zeroModTimes) {} NListSymbolTable::NListSymbolTable(NListLayout layout, NListBuffer nlist, std::vector<char> stringPoolBuffer, uint64_t prefLoadAddr, bool is64, bool zeroModTimes) : _nlistBuffer(std::move(nlist)), _stringPoolBuffer(std::move(stringPoolBuffer)) { // partition symbols into locals, globals, and undefs _localsCount = (uint32_t)layout.locals.size() + layout.debugNotesNListCount; _globalsCount = (uint32_t)layout.globals.size(); _undefsCount = (uint32_t)layout.undefs.size(); _nlistCount = _localsCount + _globalsCount + _undefsCount; assert(layout.globals.size() == layout.globalsStrx.size()); assert(layout.globals.size() == layout.reexportStrx.size()); assert(layout.undefs.size() == layout.undefsStrx.size()); assert(layout.locals.size() == layout.localsStrx.size()); std::span<uint8_t> nlistBuffer = _nlistBuffer.buffer; // convert each symbol to nlist _preferredLoadAddress = prefLoadAddr; if ( is64 ) { assert(nlistBuffer.size() == (_localsCount + _globalsCount + _undefsCount) * sizeof(nlist_64)); // symbol table strings are added in the order of globals, imports, locals // but the nlist itself is emitted as locals, globals, imports. // So we'll walk in the string order, and then create the nlist after std::span<nlist_64> nlist64Buffer = std::span<nlist_64>((nlist_64*)nlistBuffer.data(), nlistBuffer.size() / sizeof(nlist_64)); std::span<nlist_64> globalsBuffer(nlist64Buffer.subspan(_localsCount, _globalsCount)); std::span<nlist_64> undefsBuffer(nlist64Buffer.subspan(_localsCount + _globalsCount, _undefsCount)); std::span<nlist_64> localsBuffer(nlist64Buffer.subspan(0, _localsCount)); dispatchForEach(layout.globals, [this, globalsBuffer, &layout](size_t i, const Symbol& sym) { globalsBuffer[i] = nlist64FromSymbol(sym, layout.globalsStrx[i], layout.reexportStrx[i]); }); dispatchForEach(layout.undefs, [this, undefsBuffer, &layout](size_t i, const Symbol& sym) { undefsBuffer[i] = nlist64FromSymbol(sym, layout.undefsStrx[i], 0); }); dispatchForEach(layout.locals, [this, localsBuffer, &layout](size_t i, const Symbol& sym) { localsBuffer[i] = nlist64FromSymbol(sym, layout.localsStrx[i], 0); }); NListBuffer stabsBuffer = localsBuffer.subspan(layout.locals.size()); assert((stabsBuffer.buffer.size() / sizeof(nlist_64)) == layout.debugNotesNListCount); addStabsFromDebugNotes<nlist_64>(layout.debugNotes, zeroModTimes, stabsBuffer); } else { // symbol table strings are added in the order of globals, imports, locals // but the nlist itself is emitted as locals, globals, imports. // So we'll walk in the string order, and then create the nlist after std::span<struct nlist> nlist32Buffer = std::span<struct nlist>((struct nlist*)nlistBuffer.data(), nlistBuffer.size() / sizeof(struct nlist)); std::span<struct nlist> globalsBuffer(nlist32Buffer.subspan(_localsCount, _globalsCount)); std::span<struct nlist> undefsBuffer(nlist32Buffer.subspan(_localsCount + _globalsCount, _undefsCount)); std::span<struct nlist> localsBuffer(nlist32Buffer.subspan(0, _localsCount)); dispatchForEach(layout.globals, [this, globalsBuffer, &layout](size_t i, const Symbol& sym) { globalsBuffer[i] = nlistFromSymbol(sym, layout.globalsStrx[i], layout.reexportStrx[i]); }); dispatchForEach(layout.undefs, [this, undefsBuffer, &layout](size_t i, const Symbol& sym) { undefsBuffer[i] = nlistFromSymbol(sym, layout.undefsStrx[i], 0); }); dispatchForEach(layout.locals, [this, localsBuffer, &layout](size_t i, const Symbol& sym) { localsBuffer[i] = nlistFromSymbol(sym, layout.localsStrx[i], 0); }); NListBuffer stabsBuffer = localsBuffer.subspan(layout.locals.size()); assert((stabsBuffer.buffer.size() / sizeof(struct nlist)) == layout.debugNotesNListCount); addStabsFromDebugNotes<struct nlist>(layout.debugNotes, zeroModTimes, stabsBuffer); } // fill in all ivars as if this came from a mach-o file _preferredLoadAddress = prefLoadAddr; _stringPool = _stringPoolBuffer.data(); _nlist32 = is64 ? nullptr : (struct nlist*)nlistBuffer.data(); _nlist64 = is64 ? (nlist_64*)nlistBuffer.data() : nullptr; _stringPoolSize = (uint32_t)_stringPoolBuffer.size(); } static uint8_t ntypeFromSymbol(const Symbol& symbol) { switch ( symbol.scope() ) { case Symbol::Scope::global: case Symbol::Scope::globalNeverStrip: case Symbol::Scope::autoHide: return N_EXT; case Symbol::Scope::linkageUnit: return N_EXT | N_PEXT; case Symbol::Scope::translationUnit: return 0; case Symbol::Scope::wasLinkageUnit: return N_PEXT; } } static uint16_t weakDefDesc(const Symbol& symbol) { uint16_t desc = 0; if ( symbol.isWeakDef() ) { switch ( symbol.scope() ) { case Symbol::Scope::globalNeverStrip: case Symbol::Scope::global: case Symbol::Scope::linkageUnit: case Symbol::Scope::wasLinkageUnit: desc = N_WEAK_DEF; break; case Symbol::Scope::autoHide: desc = N_WEAK_DEF | N_WEAK_REF; break; case Symbol::Scope::translationUnit: break; } } return desc; } struct nlist_64 NListSymbolTable::nlist64FromSymbol(const Symbol& symbol, uint32_t strx, uint32_t reexportStrx) { struct nlist_64 result; int libOrdinal; uint64_t absAddress; bool weakImport; uint64_t implOffset; uint64_t size; uint64_t stubOffset; uint8_t p2align; const char* importName; if ( symbol.isTentativeDef(size, p2align) ) { result.n_un.n_strx = strx; result.n_type = N_UNDF | ntypeFromSymbol(symbol); result.n_sect = 0; result.n_desc = 0; result.n_value = size; SET_COMM_ALIGN(result.n_desc,p2align); } else if ( symbol.isUndefined(libOrdinal, weakImport) ) { result.n_un.n_strx = strx; result.n_type = N_UNDF | N_EXT; result.n_sect = 0; result.n_desc = (libOrdinal << 8) | (weakImport ? N_WEAK_REF : 0); result.n_value = 0; } else if ( symbol.isAbsolute(absAddress) ) { result.n_un.n_strx = strx; result.n_type = N_ABS | ntypeFromSymbol(symbol); result.n_sect = 0; result.n_desc = 0; result.n_value = absAddress; } else if ( symbol.isRegular(implOffset) || symbol.isThreadLocal(implOffset) ) { uint16_t desc = weakDefDesc(symbol); if ( symbol.dontDeadStrip() ) desc |= N_NO_DEAD_STRIP; if ( symbol.cold() ) desc |= N_COLD_FUNC; if ( symbol.scope() == Symbol::Scope::globalNeverStrip ) desc |= REFERENCED_DYNAMICALLY; result.n_un.n_strx = strx; result.n_type = N_SECT | ntypeFromSymbol(symbol); result.n_sect = symbol.sectionOrdinal(); result.n_desc = desc; result.n_value = _preferredLoadAddress + implOffset; } else if ( symbol.isAltEntry(implOffset) ) { uint64_t desc = N_ALT_ENTRY | weakDefDesc(symbol); if ( symbol.dontDeadStrip() ) desc |= N_NO_DEAD_STRIP; result.n_un.n_strx = strx; result.n_type = N_SECT | ntypeFromSymbol(symbol); result.n_sect = symbol.sectionOrdinal(); result.n_desc = desc; result.n_value = _preferredLoadAddress + implOffset; } else if ( symbol.isReExport(libOrdinal, importName) ) { // re-exports can't be local, they're always global in linked images, // in object files they can have global/linkage unit scope or be undefined. assert(symbol.scope() != Symbol::Scope::translationUnit && "re-exports can't have a translation unit"); result.n_un.n_strx = strx; result.n_type = N_INDR | ntypeFromSymbol(symbol); result.n_sect = 0; result.n_desc = 0; result.n_value = reexportStrx; } else if ( symbol.isDynamicResolver(stubOffset) ) { result.n_un.n_strx = strx; result.n_type = N_SECT | ntypeFromSymbol(symbol); result.n_sect = symbol.sectionOrdinal(); result.n_desc = N_SYMBOL_RESOLVER; result.n_value = _preferredLoadAddress + symbol.implOffset(); } else { assert(false && "unhandled symbol kind"); } return result; } // avoid duplicating code by filling in nlist_64 and converting to nlist struct nlist NListSymbolTable::nlistFromSymbol(const Symbol& symbol, uint32_t strx, uint32_t reexportStrx) { struct nlist_64 result64 = nlist64FromSymbol(symbol, strx, reexportStrx); struct nlist result; result.n_un.n_strx = result64.n_un.n_strx; result.n_type = result64.n_type; result.n_sect = result64.n_sect; result.n_desc = result64.n_desc; result.n_value = (uint32_t)result64.n_value; return result; } std::pair<uint32_t, char*> NListStringPoolBuffer::reserve(size_t size) { size_t startPos = pos; pos += size; buffer.resize(buffer.size() + size); return std::make_pair(startPos, buffer.data() + startPos); } uint32_t NListStringPoolBuffer::add(std::span<const char> bytes) { auto [startPos, ptr] = reserve(bytes.size()); memcpy(ptr, bytes.data(), bytes.size()); return startPos; } uint32_t NListStringPoolBuffer::add(char ch) { auto [startPos, ptr] = reserve(1); *ptr = ch; return startPos; } uint32_t NListStringPoolBuffer::add(CString cstr) { return add(std::span(cstr.c_str(), cstr.size() + 1)); } #endif // BUILDING_MACHO_WRITER const DebugNoteFileInfo* DebugNoteFileInfo::make(CString srcDir, CString srcName, CString objPath, uint32_t objModTime, uint8_t objSubType, CString libPath, CString originLibPath) { DebugNoteFileInfo* result = (DebugNoteFileInfo*)calloc(sizeof(DebugNoteFileInfo), sizeof(uint8_t)); result->_objModTime = objModTime; result->_objSubType = objSubType; result->_srcDir = srcDir; result->_srcName = srcName; result->_objPath = objPath; result->_libPath = libPath; result->_originLibPath = originLibPath; return result; } Error DebugNoteFileInfo::valid(std::span<const uint8_t> buffer) { return Error::none(); } const DebugNoteFileInfo* DebugNoteFileInfo::copy() const { return DebugNoteFileInfo::make(_srcDir, _srcName, _objPath, _objModTime, _objSubType, _libPath, _originLibPath); } bool DebugNoteFileInfo::shouldbeUpdated(CString libPath) const { // .o -> .dylib if ( !this->hasLibInfo() && !this->hasOriginLibInfo() ) return true; if ( strcmp(libPath.c_str(), this->libPath().c_str()) != 0 ) return true; return false; } __attribute__((used)) void DebugNoteFileInfo::dump() const { fprintf(stdout, "scrDir: %s\n", srcDir().c_str()); fprintf(stdout, "scrName: %s\n", srcName().c_str()); fprintf(stdout, "objPath: %s\n", objPath().c_str()); fprintf(stdout, "objModTime: 0x%08X\n", this->objModTime()); fprintf(stdout, "objSubType: 0X%02X\n", this->objSubType()); fprintf(stdout, "libPath: %s\n", hasLibInfo() ? libPath().c_str() : "N/A"); fprintf(stdout, "origlibPath: %s\n", hasOriginLibInfo() ? originLibPath().c_str() : "N/A"); } } // namespace mach_o |