1 //===- tools/dsymutil/MachODebugMapParser.cpp - Parse STABS debug maps ----===//
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 "BinaryHolder.h"
10 #include "DebugMap.h"
11 #include "MachOUtils.h"
12 #include "llvm/ADT/SmallSet.h"
13 #include "llvm/Object/MachO.h"
14 #include "llvm/Support/Path.h"
15 #include "llvm/Support/WithColor.h"
16 #include "llvm/Support/raw_ostream.h"
17 #include <optional>
18 #include <vector>
19
20 namespace {
21 using namespace llvm;
22 using namespace llvm::dsymutil;
23 using namespace llvm::object;
24
25 class MachODebugMapParser {
26 public:
MachODebugMapParser(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,StringRef BinaryPath,ArrayRef<std::string> Archs,StringRef PathPrefix="",bool PaperTrailWarnings=false,bool Verbose=false)27 MachODebugMapParser(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
28 StringRef BinaryPath, ArrayRef<std::string> Archs,
29 StringRef PathPrefix = "",
30 bool PaperTrailWarnings = false, bool Verbose = false)
31 : BinaryPath(std::string(BinaryPath)), Archs(Archs.begin(), Archs.end()),
32 PathPrefix(std::string(PathPrefix)),
33 PaperTrailWarnings(PaperTrailWarnings), BinHolder(VFS, Verbose),
34 CurrentDebugMapObject(nullptr) {}
35
36 /// Parses and returns the DebugMaps of the input binary. The binary contains
37 /// multiple maps in case it is a universal binary.
38 /// \returns an error in case the provided BinaryPath doesn't exist
39 /// or isn't of a supported type.
40 ErrorOr<std::vector<std::unique_ptr<DebugMap>>> parse();
41
42 /// Walk the symbol table and dump it.
43 bool dumpStab();
44
45 private:
46 std::string BinaryPath;
47 SmallVector<StringRef, 1> Archs;
48 std::string PathPrefix;
49 bool PaperTrailWarnings;
50
51 /// Owns the MemoryBuffer for the main binary.
52 BinaryHolder BinHolder;
53 /// Map of the binary symbol addresses.
54 StringMap<uint64_t> MainBinarySymbolAddresses;
55 StringRef MainBinaryStrings;
56 /// The constructed DebugMap.
57 std::unique_ptr<DebugMap> Result;
58 /// List of common symbols that need to be added to the debug map.
59 std::vector<std::string> CommonSymbols;
60
61 /// Map of the currently processed object file symbol addresses.
62 StringMap<std::optional<uint64_t>> CurrentObjectAddresses;
63
64 /// Lazily computed map of symbols aliased to the processed object file.
65 StringMap<std::optional<uint64_t>> CurrentObjectAliasMap;
66
67 /// If CurrentObjectAliasMap has been computed for a given address.
68 SmallSet<uint64_t, 4> SeenAliasValues;
69
70 /// Element of the debug map corresponding to the current object file.
71 DebugMapObject *CurrentDebugMapObject;
72
73 /// Holds function info while function scope processing.
74 const char *CurrentFunctionName;
75 uint64_t CurrentFunctionAddress;
76
77 std::unique_ptr<DebugMap> parseOneBinary(const MachOObjectFile &MainBinary,
78 StringRef BinaryPath);
79
80 void
81 switchToNewDebugMapObject(StringRef Filename,
82 sys::TimePoint<std::chrono::seconds> Timestamp);
83 void resetParserState();
84 uint64_t getMainBinarySymbolAddress(StringRef Name);
85 std::vector<StringRef> getMainBinarySymbolNames(uint64_t Value);
86 void loadMainBinarySymbols(const MachOObjectFile &MainBinary);
87 void loadCurrentObjectFileSymbols(const object::MachOObjectFile &Obj);
88 void handleStabSymbolTableEntry(uint32_t StringIndex, uint8_t Type,
89 uint8_t SectionIndex, uint16_t Flags,
90 uint64_t Value);
91
handleStabDebugMapEntry(const STEType & STE)92 template <typename STEType> void handleStabDebugMapEntry(const STEType &STE) {
93 handleStabSymbolTableEntry(STE.n_strx, STE.n_type, STE.n_sect, STE.n_desc,
94 STE.n_value);
95 }
96
97 void addCommonSymbols();
98
99 /// Dump the symbol table output header.
100 void dumpSymTabHeader(raw_ostream &OS, StringRef Arch);
101
102 /// Dump the contents of nlist entries.
103 void dumpSymTabEntry(raw_ostream &OS, uint64_t Index, uint32_t StringIndex,
104 uint8_t Type, uint8_t SectionIndex, uint16_t Flags,
105 uint64_t Value);
106
107 template <typename STEType>
dumpSymTabEntry(raw_ostream & OS,uint64_t Index,const STEType & STE)108 void dumpSymTabEntry(raw_ostream &OS, uint64_t Index, const STEType &STE) {
109 dumpSymTabEntry(OS, Index, STE.n_strx, STE.n_type, STE.n_sect, STE.n_desc,
110 STE.n_value);
111 }
112 void dumpOneBinaryStab(const MachOObjectFile &MainBinary,
113 StringRef BinaryPath);
114
Warning(const Twine & Msg,StringRef File=StringRef ())115 void Warning(const Twine &Msg, StringRef File = StringRef()) {
116 WithColor::warning() << "("
117 << MachOUtils::getArchName(
118 Result->getTriple().getArchName())
119 << ") " << File << " " << Msg << "\n";
120
121 if (PaperTrailWarnings) {
122 if (!File.empty())
123 Result->addDebugMapObject(File, sys::TimePoint<std::chrono::seconds>());
124 if (Result->end() != Result->begin())
125 (*--Result->end())->addWarning(Msg.str());
126 }
127 }
128 };
129
130 } // anonymous namespace
131
132 /// Reset the parser state corresponding to the current object
133 /// file. This is to be called after an object file is finished
134 /// processing.
resetParserState()135 void MachODebugMapParser::resetParserState() {
136 CommonSymbols.clear();
137 CurrentObjectAddresses.clear();
138 CurrentObjectAliasMap.clear();
139 SeenAliasValues.clear();
140 CurrentDebugMapObject = nullptr;
141 }
142
143 /// Commons symbols won't show up in the symbol map but might need to be
144 /// relocated. We can add them to the symbol table ourselves by combining the
145 /// information in the object file (the symbol name) and the main binary (the
146 /// address).
addCommonSymbols()147 void MachODebugMapParser::addCommonSymbols() {
148 for (auto &CommonSymbol : CommonSymbols) {
149 uint64_t CommonAddr = getMainBinarySymbolAddress(CommonSymbol);
150 if (CommonAddr == 0) {
151 // The main binary doesn't have an address for the given symbol.
152 continue;
153 }
154 if (!CurrentDebugMapObject->addSymbol(CommonSymbol,
155 std::nullopt /*ObjectAddress*/,
156 CommonAddr, 0 /*size*/)) {
157 // The symbol is already present.
158 continue;
159 }
160 }
161 }
162
163 /// Create a new DebugMapObject. This function resets the state of the
164 /// parser that was referring to the last object file and sets
165 /// everything up to add symbols to the new one.
switchToNewDebugMapObject(StringRef Filename,sys::TimePoint<std::chrono::seconds> Timestamp)166 void MachODebugMapParser::switchToNewDebugMapObject(
167 StringRef Filename, sys::TimePoint<std::chrono::seconds> Timestamp) {
168 addCommonSymbols();
169 resetParserState();
170
171 SmallString<80> Path(PathPrefix);
172 sys::path::append(Path, Filename);
173
174 auto ObjectEntry = BinHolder.getObjectEntry(Path, Timestamp);
175 if (!ObjectEntry) {
176 auto Err = ObjectEntry.takeError();
177 Warning("unable to open object file: " + toString(std::move(Err)),
178 Path.str());
179 return;
180 }
181
182 auto Object = ObjectEntry->getObjectAs<MachOObjectFile>(Result->getTriple());
183 if (!Object) {
184 auto Err = Object.takeError();
185 Warning("unable to open object file: " + toString(std::move(Err)),
186 Path.str());
187 return;
188 }
189
190 CurrentDebugMapObject =
191 &Result->addDebugMapObject(Path, Timestamp, MachO::N_OSO);
192 loadCurrentObjectFileSymbols(*Object);
193 }
194
getArchName(const object::MachOObjectFile & Obj)195 static std::string getArchName(const object::MachOObjectFile &Obj) {
196 Triple T = Obj.getArchTriple();
197 return std::string(T.getArchName());
198 }
199
200 std::unique_ptr<DebugMap>
parseOneBinary(const MachOObjectFile & MainBinary,StringRef BinaryPath)201 MachODebugMapParser::parseOneBinary(const MachOObjectFile &MainBinary,
202 StringRef BinaryPath) {
203 loadMainBinarySymbols(MainBinary);
204 ArrayRef<uint8_t> UUID = MainBinary.getUuid();
205 Result =
206 std::make_unique<DebugMap>(MainBinary.getArchTriple(), BinaryPath, UUID);
207 MainBinaryStrings = MainBinary.getStringTableData();
208 for (const SymbolRef &Symbol : MainBinary.symbols()) {
209 const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
210 if (MainBinary.is64Bit())
211 handleStabDebugMapEntry(MainBinary.getSymbol64TableEntry(DRI));
212 else
213 handleStabDebugMapEntry(MainBinary.getSymbolTableEntry(DRI));
214 }
215
216 resetParserState();
217 return std::move(Result);
218 }
219
220 // Table that maps Darwin's Mach-O stab constants to strings to allow printing.
221 // llvm-nm has very similar code, the strings used here are however slightly
222 // different and part of the interface of dsymutil (some project's build-systems
223 // parse the ouptut of dsymutil -s), thus they shouldn't be changed.
224 struct DarwinStabName {
225 uint8_t NType;
226 const char *Name;
227 };
228
229 const struct DarwinStabName DarwinStabNames[] = {
230 {MachO::N_GSYM, "N_GSYM"}, {MachO::N_FNAME, "N_FNAME"},
231 {MachO::N_FUN, "N_FUN"}, {MachO::N_STSYM, "N_STSYM"},
232 {MachO::N_LCSYM, "N_LCSYM"}, {MachO::N_BNSYM, "N_BNSYM"},
233 {MachO::N_PC, "N_PC"}, {MachO::N_AST, "N_AST"},
234 {MachO::N_OPT, "N_OPT"}, {MachO::N_RSYM, "N_RSYM"},
235 {MachO::N_SLINE, "N_SLINE"}, {MachO::N_ENSYM, "N_ENSYM"},
236 {MachO::N_SSYM, "N_SSYM"}, {MachO::N_SO, "N_SO"},
237 {MachO::N_OSO, "N_OSO"}, {MachO::N_LSYM, "N_LSYM"},
238 {MachO::N_BINCL, "N_BINCL"}, {MachO::N_SOL, "N_SOL"},
239 {MachO::N_PARAMS, "N_PARAM"}, {MachO::N_VERSION, "N_VERS"},
240 {MachO::N_OLEVEL, "N_OLEV"}, {MachO::N_PSYM, "N_PSYM"},
241 {MachO::N_EINCL, "N_EINCL"}, {MachO::N_ENTRY, "N_ENTRY"},
242 {MachO::N_LBRAC, "N_LBRAC"}, {MachO::N_EXCL, "N_EXCL"},
243 {MachO::N_RBRAC, "N_RBRAC"}, {MachO::N_BCOMM, "N_BCOMM"},
244 {MachO::N_ECOMM, "N_ECOMM"}, {MachO::N_ECOML, "N_ECOML"},
245 {MachO::N_LENG, "N_LENG"}, {0, nullptr}};
246
getDarwinStabString(uint8_t NType)247 static const char *getDarwinStabString(uint8_t NType) {
248 for (unsigned i = 0; DarwinStabNames[i].Name; i++) {
249 if (DarwinStabNames[i].NType == NType)
250 return DarwinStabNames[i].Name;
251 }
252 return nullptr;
253 }
254
dumpSymTabHeader(raw_ostream & OS,StringRef Arch)255 void MachODebugMapParser::dumpSymTabHeader(raw_ostream &OS, StringRef Arch) {
256 OS << "-----------------------------------"
257 "-----------------------------------\n";
258 OS << "Symbol table for: '" << BinaryPath << "' (" << Arch.data() << ")\n";
259 OS << "-----------------------------------"
260 "-----------------------------------\n";
261 OS << "Index n_strx n_type n_sect n_desc n_value\n";
262 OS << "======== -------- ------------------ ------ ------ ----------------\n";
263 }
264
dumpSymTabEntry(raw_ostream & OS,uint64_t Index,uint32_t StringIndex,uint8_t Type,uint8_t SectionIndex,uint16_t Flags,uint64_t Value)265 void MachODebugMapParser::dumpSymTabEntry(raw_ostream &OS, uint64_t Index,
266 uint32_t StringIndex, uint8_t Type,
267 uint8_t SectionIndex, uint16_t Flags,
268 uint64_t Value) {
269 // Index
270 OS << '[' << format_decimal(Index, 6)
271 << "] "
272 // n_strx
273 << format_hex_no_prefix(StringIndex, 8)
274 << ' '
275 // n_type...
276 << format_hex_no_prefix(Type, 2) << " (";
277
278 if (Type & MachO::N_STAB)
279 OS << left_justify(getDarwinStabString(Type), 13);
280 else {
281 if (Type & MachO::N_PEXT)
282 OS << "PEXT ";
283 else
284 OS << " ";
285 switch (Type & MachO::N_TYPE) {
286 case MachO::N_UNDF: // 0x0 undefined, n_sect == NO_SECT
287 OS << "UNDF";
288 break;
289 case MachO::N_ABS: // 0x2 absolute, n_sect == NO_SECT
290 OS << "ABS ";
291 break;
292 case MachO::N_SECT: // 0xe defined in section number n_sect
293 OS << "SECT";
294 break;
295 case MachO::N_PBUD: // 0xc prebound undefined (defined in a dylib)
296 OS << "PBUD";
297 break;
298 case MachO::N_INDR: // 0xa indirect
299 OS << "INDR";
300 break;
301 default:
302 OS << format_hex_no_prefix(Type, 2) << " ";
303 break;
304 }
305 if (Type & MachO::N_EXT)
306 OS << " EXT";
307 else
308 OS << " ";
309 }
310
311 OS << ") "
312 // n_sect
313 << format_hex_no_prefix(SectionIndex, 2)
314 << " "
315 // n_desc
316 << format_hex_no_prefix(Flags, 4)
317 << " "
318 // n_value
319 << format_hex_no_prefix(Value, 16);
320
321 const char *Name = &MainBinaryStrings.data()[StringIndex];
322 if (Name && Name[0])
323 OS << " '" << Name << "'";
324
325 OS << "\n";
326 }
327
dumpOneBinaryStab(const MachOObjectFile & MainBinary,StringRef BinaryPath)328 void MachODebugMapParser::dumpOneBinaryStab(const MachOObjectFile &MainBinary,
329 StringRef BinaryPath) {
330 loadMainBinarySymbols(MainBinary);
331 MainBinaryStrings = MainBinary.getStringTableData();
332 raw_ostream &OS(llvm::outs());
333
334 dumpSymTabHeader(OS, getArchName(MainBinary));
335 uint64_t Idx = 0;
336 for (const SymbolRef &Symbol : MainBinary.symbols()) {
337 const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
338 if (MainBinary.is64Bit())
339 dumpSymTabEntry(OS, Idx, MainBinary.getSymbol64TableEntry(DRI));
340 else
341 dumpSymTabEntry(OS, Idx, MainBinary.getSymbolTableEntry(DRI));
342 Idx++;
343 }
344
345 OS << "\n\n";
346 resetParserState();
347 }
348
shouldLinkArch(SmallVectorImpl<StringRef> & Archs,StringRef Arch)349 static bool shouldLinkArch(SmallVectorImpl<StringRef> &Archs, StringRef Arch) {
350 if (Archs.empty() || is_contained(Archs, "all") || is_contained(Archs, "*"))
351 return true;
352
353 if (Arch.startswith("arm") && Arch != "arm64" && is_contained(Archs, "arm"))
354 return true;
355
356 SmallString<16> ArchName = Arch;
357 if (Arch.startswith("thumb"))
358 ArchName = ("arm" + Arch.substr(5)).str();
359
360 return is_contained(Archs, ArchName);
361 }
362
dumpStab()363 bool MachODebugMapParser::dumpStab() {
364 auto ObjectEntry = BinHolder.getObjectEntry(BinaryPath);
365 if (!ObjectEntry) {
366 auto Err = ObjectEntry.takeError();
367 WithColor::error() << "cannot load '" << BinaryPath
368 << "': " << toString(std::move(Err)) << '\n';
369 return false;
370 }
371
372 auto Objects = ObjectEntry->getObjectsAs<MachOObjectFile>();
373 if (!Objects) {
374 auto Err = Objects.takeError();
375 WithColor::error() << "cannot get '" << BinaryPath
376 << "' as MachO file: " << toString(std::move(Err))
377 << "\n";
378 return false;
379 }
380
381 for (const auto *Object : *Objects)
382 if (shouldLinkArch(Archs, Object->getArchTriple().getArchName()))
383 dumpOneBinaryStab(*Object, BinaryPath);
384
385 return true;
386 }
387
388 /// This main parsing routine tries to open the main binary and if
389 /// successful iterates over the STAB entries. The real parsing is
390 /// done in handleStabSymbolTableEntry.
parse()391 ErrorOr<std::vector<std::unique_ptr<DebugMap>>> MachODebugMapParser::parse() {
392 auto ObjectEntry = BinHolder.getObjectEntry(BinaryPath);
393 if (!ObjectEntry) {
394 return errorToErrorCode(ObjectEntry.takeError());
395 }
396
397 auto Objects = ObjectEntry->getObjectsAs<MachOObjectFile>();
398 if (!Objects) {
399 return errorToErrorCode(Objects.takeError());
400 }
401
402 std::vector<std::unique_ptr<DebugMap>> Results;
403 for (const auto *Object : *Objects)
404 if (shouldLinkArch(Archs, Object->getArchTriple().getArchName()))
405 Results.push_back(parseOneBinary(*Object, BinaryPath));
406
407 return std::move(Results);
408 }
409
410 /// Interpret the STAB entries to fill the DebugMap.
handleStabSymbolTableEntry(uint32_t StringIndex,uint8_t Type,uint8_t SectionIndex,uint16_t Flags,uint64_t Value)411 void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
412 uint8_t Type,
413 uint8_t SectionIndex,
414 uint16_t Flags,
415 uint64_t Value) {
416 if (!(Type & MachO::N_STAB))
417 return;
418
419 const char *Name = &MainBinaryStrings.data()[StringIndex];
420
421 // An N_OSO entry represents the start of a new object file description.
422 if (Type == MachO::N_OSO)
423 return switchToNewDebugMapObject(Name, sys::toTimePoint(Value));
424
425 if (Type == MachO::N_AST) {
426 SmallString<80> Path(PathPrefix);
427 sys::path::append(Path, Name);
428 Result->addDebugMapObject(Path, sys::toTimePoint(Value), Type);
429 return;
430 }
431
432 // If the last N_OSO object file wasn't found, CurrentDebugMapObject will be
433 // null. Do not update anything until we find the next valid N_OSO entry.
434 if (!CurrentDebugMapObject)
435 return;
436
437 uint32_t Size = 0;
438 switch (Type) {
439 case MachO::N_GSYM:
440 // This is a global variable. We need to query the main binary
441 // symbol table to find its address as it might not be in the
442 // debug map (for common symbols).
443 Value = getMainBinarySymbolAddress(Name);
444 break;
445 case MachO::N_FUN:
446 // Functions are scopes in STABS. They have an end marker that
447 // contains the function size.
448 if (Name[0] == '\0') {
449 Size = Value;
450 Value = CurrentFunctionAddress;
451 Name = CurrentFunctionName;
452 break;
453 } else {
454 CurrentFunctionName = Name;
455 CurrentFunctionAddress = Value;
456 return;
457 }
458 case MachO::N_STSYM:
459 break;
460 default:
461 return;
462 }
463
464 auto ObjectSymIt = CurrentObjectAddresses.find(Name);
465
466 // If the name of a (non-static) symbol is not in the current object, we
467 // check all its aliases from the main binary.
468 if (ObjectSymIt == CurrentObjectAddresses.end() && Type != MachO::N_STSYM) {
469 if (SeenAliasValues.count(Value) == 0) {
470 auto Aliases = getMainBinarySymbolNames(Value);
471 for (const auto &Alias : Aliases) {
472 auto It = CurrentObjectAddresses.find(Alias);
473 if (It != CurrentObjectAddresses.end()) {
474 auto AliasValue = It->getValue();
475 for (const auto &Alias : Aliases)
476 CurrentObjectAliasMap[Alias] = AliasValue;
477 break;
478 }
479 }
480 SeenAliasValues.insert(Value);
481 }
482
483 auto AliasIt = CurrentObjectAliasMap.find(Name);
484 if (AliasIt != CurrentObjectAliasMap.end())
485 ObjectSymIt = AliasIt;
486 }
487
488 // ThinLTO adds a unique suffix to exported private symbols.
489 if (ObjectSymIt == CurrentObjectAddresses.end()) {
490 for (auto Iter = CurrentObjectAddresses.begin();
491 Iter != CurrentObjectAddresses.end(); ++Iter) {
492 llvm::StringRef SymbolName = Iter->getKey();
493 auto Pos = SymbolName.rfind(".llvm.");
494 if (Pos != llvm::StringRef::npos && SymbolName.substr(0, Pos) == Name) {
495 ObjectSymIt = Iter;
496 break;
497 }
498 }
499 }
500
501 if (ObjectSymIt == CurrentObjectAddresses.end()) {
502 Warning("could not find object file symbol for symbol " + Twine(Name));
503 return;
504 }
505
506 if (!CurrentDebugMapObject->addSymbol(Name, ObjectSymIt->getValue(), Value,
507 Size)) {
508 Warning(Twine("failed to insert symbol '") + Name + "' in the debug map.");
509 return;
510 }
511 }
512
513 /// Load the current object file symbols into CurrentObjectAddresses.
loadCurrentObjectFileSymbols(const object::MachOObjectFile & Obj)514 void MachODebugMapParser::loadCurrentObjectFileSymbols(
515 const object::MachOObjectFile &Obj) {
516 CurrentObjectAddresses.clear();
517
518 for (auto Sym : Obj.symbols()) {
519 uint64_t Addr = cantFail(Sym.getValue());
520 Expected<StringRef> Name = Sym.getName();
521 if (!Name) {
522 auto Err = Name.takeError();
523 Warning("failed to get symbol name: " + toString(std::move(Err)),
524 Obj.getFileName());
525 continue;
526 }
527 // The value of some categories of symbols isn't meaningful. For
528 // example common symbols store their size in the value field, not
529 // their address. Absolute symbols have a fixed address that can
530 // conflict with standard symbols. These symbols (especially the
531 // common ones), might still be referenced by relocations. These
532 // relocations will use the symbol itself, and won't need an
533 // object file address. The object file address field is optional
534 // in the DebugMap, leave it unassigned for these symbols.
535 uint32_t Flags = cantFail(Sym.getFlags());
536 if (Flags & SymbolRef::SF_Absolute) {
537 CurrentObjectAddresses[*Name] = std::nullopt;
538 } else if (Flags & SymbolRef::SF_Common) {
539 CurrentObjectAddresses[*Name] = std::nullopt;
540 CommonSymbols.push_back(std::string(*Name));
541 } else {
542 CurrentObjectAddresses[*Name] = Addr;
543 }
544 }
545 }
546
547 /// Lookup a symbol address in the main binary symbol table. The
548 /// parser only needs to query common symbols, thus not every symbol's
549 /// address is available through this function.
getMainBinarySymbolAddress(StringRef Name)550 uint64_t MachODebugMapParser::getMainBinarySymbolAddress(StringRef Name) {
551 auto Sym = MainBinarySymbolAddresses.find(Name);
552 if (Sym == MainBinarySymbolAddresses.end())
553 return 0;
554 return Sym->second;
555 }
556
557 /// Get all symbol names in the main binary for the given value.
558 std::vector<StringRef>
getMainBinarySymbolNames(uint64_t Value)559 MachODebugMapParser::getMainBinarySymbolNames(uint64_t Value) {
560 std::vector<StringRef> Names;
561 for (const auto &Entry : MainBinarySymbolAddresses) {
562 if (Entry.second == Value)
563 Names.push_back(Entry.first());
564 }
565 return Names;
566 }
567
568 /// Load the interesting main binary symbols' addresses into
569 /// MainBinarySymbolAddresses.
loadMainBinarySymbols(const MachOObjectFile & MainBinary)570 void MachODebugMapParser::loadMainBinarySymbols(
571 const MachOObjectFile &MainBinary) {
572 section_iterator Section = MainBinary.section_end();
573 MainBinarySymbolAddresses.clear();
574 for (const auto &Sym : MainBinary.symbols()) {
575 Expected<SymbolRef::Type> TypeOrErr = Sym.getType();
576 if (!TypeOrErr) {
577 auto Err = TypeOrErr.takeError();
578 Warning("failed to get symbol type: " + toString(std::move(Err)),
579 MainBinary.getFileName());
580 continue;
581 }
582 SymbolRef::Type Type = *TypeOrErr;
583 // Skip undefined and STAB entries.
584 if ((Type == SymbolRef::ST_Debug) || (Type == SymbolRef::ST_Unknown))
585 continue;
586 // In theory, the only symbols of interest are the global variables. These
587 // are the only ones that need to be queried because the address of common
588 // data won't be described in the debug map. All other addresses should be
589 // fetched for the debug map. In reality, by playing with 'ld -r' and
590 // export lists, you can get symbols described as N_GSYM in the debug map,
591 // but associated with a local symbol. Gather all the symbols, but prefer
592 // the global ones.
593 uint8_t SymType =
594 MainBinary.getSymbolTableEntry(Sym.getRawDataRefImpl()).n_type;
595 bool Extern = SymType & (MachO::N_EXT | MachO::N_PEXT);
596 Expected<section_iterator> SectionOrErr = Sym.getSection();
597 if (!SectionOrErr) {
598 auto Err = TypeOrErr.takeError();
599 Warning("failed to get symbol section: " + toString(std::move(Err)),
600 MainBinary.getFileName());
601 continue;
602 }
603 Section = *SectionOrErr;
604 if ((Section == MainBinary.section_end() || Section->isText()) && !Extern)
605 continue;
606 uint64_t Addr = cantFail(Sym.getValue());
607 Expected<StringRef> NameOrErr = Sym.getName();
608 if (!NameOrErr) {
609 auto Err = NameOrErr.takeError();
610 Warning("failed to get symbol name: " + toString(std::move(Err)),
611 MainBinary.getFileName());
612 continue;
613 }
614 StringRef Name = *NameOrErr;
615 if (Name.size() == 0 || Name[0] == '\0')
616 continue;
617 // Override only if the new key is global.
618 if (Extern)
619 MainBinarySymbolAddresses[Name] = Addr;
620 else
621 MainBinarySymbolAddresses.try_emplace(Name, Addr);
622 }
623 }
624
625 namespace llvm {
626 namespace dsymutil {
627 llvm::ErrorOr<std::vector<std::unique_ptr<DebugMap>>>
parseDebugMap(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,StringRef InputFile,ArrayRef<std::string> Archs,StringRef PrependPath,bool PaperTrailWarnings,bool Verbose,bool InputIsYAML)628 parseDebugMap(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
629 StringRef InputFile, ArrayRef<std::string> Archs,
630 StringRef PrependPath, bool PaperTrailWarnings, bool Verbose,
631 bool InputIsYAML) {
632 if (InputIsYAML)
633 return DebugMap::parseYAMLDebugMap(InputFile, PrependPath, Verbose);
634
635 MachODebugMapParser Parser(VFS, InputFile, Archs, PrependPath,
636 PaperTrailWarnings, Verbose);
637 return Parser.parse();
638 }
639
dumpStab(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,StringRef InputFile,ArrayRef<std::string> Archs,StringRef PrependPath)640 bool dumpStab(llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
641 StringRef InputFile, ArrayRef<std::string> Archs,
642 StringRef PrependPath) {
643 MachODebugMapParser Parser(VFS, InputFile, Archs, PrependPath, false);
644 return Parser.dumpStab();
645 }
646 } // namespace dsymutil
647 } // namespace llvm
648