1 //===- ObjectFile.h - File format independent object file -------*- 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 // This file declares a file format independent ObjectFile class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_OBJECT_OBJECTFILE_H 14 #define LLVM_OBJECT_OBJECTFILE_H 15 16 #include "llvm/ADT/DenseMapInfo.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/ADT/Triple.h" 19 #include "llvm/ADT/iterator_range.h" 20 #include "llvm/BinaryFormat/Magic.h" 21 #include "llvm/MC/SubtargetFeature.h" 22 #include "llvm/Object/Binary.h" 23 #include "llvm/Object/Error.h" 24 #include "llvm/Object/SymbolicFile.h" 25 #include "llvm/Support/Casting.h" 26 #include "llvm/Support/Error.h" 27 #include "llvm/Support/FileSystem.h" 28 #include "llvm/Support/MemoryBuffer.h" 29 #include <cassert> 30 #include <cstdint> 31 #include <memory> 32 #include <system_error> 33 34 namespace llvm { 35 36 class ARMAttributeParser; 37 38 namespace object { 39 40 class COFFObjectFile; 41 class MachOObjectFile; 42 class ObjectFile; 43 class SectionRef; 44 class SymbolRef; 45 class symbol_iterator; 46 class WasmObjectFile; 47 48 using section_iterator = content_iterator<SectionRef>; 49 50 /// This is a value type class that represents a single relocation in the list 51 /// of relocations in the object file. 52 class RelocationRef { 53 DataRefImpl RelocationPimpl; 54 const ObjectFile *OwningObject = nullptr; 55 56 public: 57 RelocationRef() = default; 58 RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner); 59 60 bool operator==(const RelocationRef &Other) const; 61 62 void moveNext(); 63 64 uint64_t getOffset() const; 65 symbol_iterator getSymbol() const; 66 uint64_t getType() const; 67 68 /// Get a string that represents the type of this relocation. 69 /// 70 /// This is for display purposes only. 71 void getTypeName(SmallVectorImpl<char> &Result) const; 72 73 DataRefImpl getRawDataRefImpl() const; 74 const ObjectFile *getObject() const; 75 }; 76 77 using relocation_iterator = content_iterator<RelocationRef>; 78 79 /// This is a value type class that represents a single section in the list of 80 /// sections in the object file. 81 class SectionRef { 82 friend class SymbolRef; 83 84 DataRefImpl SectionPimpl; 85 const ObjectFile *OwningObject = nullptr; 86 87 public: 88 SectionRef() = default; 89 SectionRef(DataRefImpl SectionP, const ObjectFile *Owner); 90 91 bool operator==(const SectionRef &Other) const; 92 bool operator!=(const SectionRef &Other) const; 93 bool operator<(const SectionRef &Other) const; 94 95 void moveNext(); 96 97 Expected<StringRef> getName() const; 98 uint64_t getAddress() const; 99 uint64_t getIndex() const; 100 uint64_t getSize() const; 101 Expected<StringRef> getContents() const; 102 103 /// Get the alignment of this section as the actual value (not log 2). 104 uint64_t getAlignment() const; 105 106 bool isCompressed() const; 107 /// Whether this section contains instructions. 108 bool isText() const; 109 /// Whether this section contains data, not instructions. 110 bool isData() const; 111 /// Whether this section contains BSS uninitialized data. 112 bool isBSS() const; 113 bool isVirtual() const; 114 bool isBitcode() const; 115 bool isStripped() const; 116 117 /// Whether this section will be placed in the text segment, according to the 118 /// Berkeley size format. This is true if the section is allocatable, and 119 /// contains either code or readonly data. 120 bool isBerkeleyText() const; 121 /// Whether this section will be placed in the data segment, according to the 122 /// Berkeley size format. This is true if the section is allocatable and 123 /// contains data (e.g. PROGBITS), but is not text. 124 bool isBerkeleyData() const; 125 126 bool containsSymbol(SymbolRef S) const; 127 128 relocation_iterator relocation_begin() const; 129 relocation_iterator relocation_end() const; 130 iterator_range<relocation_iterator> relocations() const { 131 return make_range(relocation_begin(), relocation_end()); 132 } 133 Expected<section_iterator> getRelocatedSection() const; 134 135 DataRefImpl getRawDataRefImpl() const; 136 const ObjectFile *getObject() const; 137 }; 138 139 struct SectionedAddress { 140 const static uint64_t UndefSection = UINT64_MAX; 141 142 uint64_t Address = 0; 143 uint64_t SectionIndex = UndefSection; 144 }; 145 146 inline bool operator<(const SectionedAddress &LHS, 147 const SectionedAddress &RHS) { 148 return std::tie(LHS.SectionIndex, LHS.Address) < 149 std::tie(RHS.SectionIndex, RHS.Address); 150 } 151 152 inline bool operator==(const SectionedAddress &LHS, 153 const SectionedAddress &RHS) { 154 return std::tie(LHS.SectionIndex, LHS.Address) == 155 std::tie(RHS.SectionIndex, RHS.Address); 156 } 157 158 raw_ostream &operator<<(raw_ostream &OS, const SectionedAddress &Addr); 159 160 /// This is a value type class that represents a single symbol in the list of 161 /// symbols in the object file. 162 class SymbolRef : public BasicSymbolRef { 163 friend class SectionRef; 164 165 public: 166 enum Type { 167 ST_Unknown, // Type not specified 168 ST_Data, 169 ST_Debug, 170 ST_File, 171 ST_Function, 172 ST_Other 173 }; 174 175 SymbolRef() = default; 176 SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner); 177 SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) { 178 assert(isa<ObjectFile>(BasicSymbolRef::getObject())); 179 } 180 181 Expected<StringRef> getName() const; 182 /// Returns the symbol virtual address (i.e. address at which it will be 183 /// mapped). 184 Expected<uint64_t> getAddress() const; 185 186 /// Return the value of the symbol depending on the object this can be an 187 /// offset or a virtual address. 188 uint64_t getValue() const; 189 190 /// Get the alignment of this symbol as the actual value (not log 2). 191 uint32_t getAlignment() const; 192 uint64_t getCommonSize() const; 193 Expected<SymbolRef::Type> getType() const; 194 195 /// Get section this symbol is defined in reference to. Result is 196 /// end_sections() if it is undefined or is an absolute symbol. 197 Expected<section_iterator> getSection() const; 198 199 const ObjectFile *getObject() const; 200 }; 201 202 class symbol_iterator : public basic_symbol_iterator { 203 public: 204 symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {} 205 symbol_iterator(const basic_symbol_iterator &B) 206 : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(), 207 cast<ObjectFile>(B->getObject()))) {} 208 209 const SymbolRef *operator->() const { 210 const BasicSymbolRef &P = basic_symbol_iterator::operator *(); 211 return static_cast<const SymbolRef*>(&P); 212 } 213 214 const SymbolRef &operator*() const { 215 const BasicSymbolRef &P = basic_symbol_iterator::operator *(); 216 return static_cast<const SymbolRef&>(P); 217 } 218 }; 219 220 /// This class is the base class for all object file types. Concrete instances 221 /// of this object are created by createObjectFile, which figures out which type 222 /// to create. 223 class ObjectFile : public SymbolicFile { 224 virtual void anchor(); 225 226 protected: 227 ObjectFile(unsigned int Type, MemoryBufferRef Source); 228 229 const uint8_t *base() const { 230 return reinterpret_cast<const uint8_t *>(Data.getBufferStart()); 231 } 232 233 // These functions are for SymbolRef to call internally. The main goal of 234 // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol 235 // entry in the memory mapped object file. SymbolPimpl cannot contain any 236 // virtual functions because then it could not point into the memory mapped 237 // file. 238 // 239 // Implementations assume that the DataRefImpl is valid and has not been 240 // modified externally. It's UB otherwise. 241 friend class SymbolRef; 242 243 virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0; 244 Error printSymbolName(raw_ostream &OS, 245 DataRefImpl Symb) const override; 246 virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0; 247 virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0; 248 virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const; 249 virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0; 250 virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0; 251 virtual Expected<section_iterator> 252 getSymbolSection(DataRefImpl Symb) const = 0; 253 254 // Same as above for SectionRef. 255 friend class SectionRef; 256 257 virtual void moveSectionNext(DataRefImpl &Sec) const = 0; 258 virtual Expected<StringRef> getSectionName(DataRefImpl Sec) const = 0; 259 virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0; 260 virtual uint64_t getSectionIndex(DataRefImpl Sec) const = 0; 261 virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0; 262 virtual Expected<ArrayRef<uint8_t>> 263 getSectionContents(DataRefImpl Sec) const = 0; 264 virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0; 265 virtual bool isSectionCompressed(DataRefImpl Sec) const = 0; 266 virtual bool isSectionText(DataRefImpl Sec) const = 0; 267 virtual bool isSectionData(DataRefImpl Sec) const = 0; 268 virtual bool isSectionBSS(DataRefImpl Sec) const = 0; 269 // A section is 'virtual' if its contents aren't present in the object image. 270 virtual bool isSectionVirtual(DataRefImpl Sec) const = 0; 271 virtual bool isSectionBitcode(DataRefImpl Sec) const; 272 virtual bool isSectionStripped(DataRefImpl Sec) const; 273 virtual bool isBerkeleyText(DataRefImpl Sec) const; 274 virtual bool isBerkeleyData(DataRefImpl Sec) const; 275 virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0; 276 virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0; 277 virtual Expected<section_iterator> getRelocatedSection(DataRefImpl Sec) const; 278 279 // Same as above for RelocationRef. 280 friend class RelocationRef; 281 virtual void moveRelocationNext(DataRefImpl &Rel) const = 0; 282 virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0; 283 virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0; 284 virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0; 285 virtual void getRelocationTypeName(DataRefImpl Rel, 286 SmallVectorImpl<char> &Result) const = 0; 287 288 uint64_t getSymbolValue(DataRefImpl Symb) const; 289 290 public: 291 ObjectFile() = delete; 292 ObjectFile(const ObjectFile &other) = delete; 293 294 uint64_t getCommonSymbolSize(DataRefImpl Symb) const { 295 assert(getSymbolFlags(Symb) & SymbolRef::SF_Common); 296 return getCommonSymbolSizeImpl(Symb); 297 } 298 299 virtual std::vector<SectionRef> dynamic_relocation_sections() const { 300 return std::vector<SectionRef>(); 301 } 302 303 using symbol_iterator_range = iterator_range<symbol_iterator>; 304 symbol_iterator_range symbols() const { 305 return symbol_iterator_range(symbol_begin(), symbol_end()); 306 } 307 308 virtual section_iterator section_begin() const = 0; 309 virtual section_iterator section_end() const = 0; 310 311 using section_iterator_range = iterator_range<section_iterator>; 312 section_iterator_range sections() const { 313 return section_iterator_range(section_begin(), section_end()); 314 } 315 316 /// The number of bytes used to represent an address in this object 317 /// file format. 318 virtual uint8_t getBytesInAddress() const = 0; 319 320 virtual StringRef getFileFormatName() const = 0; 321 virtual Triple::ArchType getArch() const = 0; 322 virtual SubtargetFeatures getFeatures() const = 0; 323 virtual void setARMSubArch(Triple &TheTriple) const { } 324 virtual Expected<uint64_t> getStartAddress() const { 325 return errorCodeToError(object_error::parse_failed); 326 }; 327 328 /// Create a triple from the data in this object file. 329 Triple makeTriple() const; 330 331 /// Maps a debug section name to a standard DWARF section name. 332 virtual StringRef mapDebugSectionName(StringRef Name) const { return Name; } 333 334 /// True if this is a relocatable object (.o/.obj). 335 virtual bool isRelocatableObject() const = 0; 336 337 /// @returns Pointer to ObjectFile subclass to handle this type of object. 338 /// @param ObjectPath The path to the object file. ObjectPath.isObject must 339 /// return true. 340 /// Create ObjectFile from path. 341 static Expected<OwningBinary<ObjectFile>> 342 createObjectFile(StringRef ObjectPath); 343 344 static Expected<std::unique_ptr<ObjectFile>> 345 createObjectFile(MemoryBufferRef Object, llvm::file_magic Type); 346 static Expected<std::unique_ptr<ObjectFile>> 347 createObjectFile(MemoryBufferRef Object) { 348 return createObjectFile(Object, llvm::file_magic::unknown); 349 } 350 351 static bool classof(const Binary *v) { 352 return v->isObject(); 353 } 354 355 static Expected<std::unique_ptr<COFFObjectFile>> 356 createCOFFObjectFile(MemoryBufferRef Object); 357 358 static Expected<std::unique_ptr<ObjectFile>> 359 createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType); 360 361 static Expected<std::unique_ptr<ObjectFile>> 362 createELFObjectFile(MemoryBufferRef Object); 363 364 static Expected<std::unique_ptr<MachOObjectFile>> 365 createMachOObjectFile(MemoryBufferRef Object, 366 uint32_t UniversalCputype = 0, 367 uint32_t UniversalIndex = 0); 368 369 static Expected<std::unique_ptr<WasmObjectFile>> 370 createWasmObjectFile(MemoryBufferRef Object); 371 }; 372 373 // Inline function definitions. 374 inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner) 375 : BasicSymbolRef(SymbolP, Owner) {} 376 377 inline Expected<StringRef> SymbolRef::getName() const { 378 return getObject()->getSymbolName(getRawDataRefImpl()); 379 } 380 381 inline Expected<uint64_t> SymbolRef::getAddress() const { 382 return getObject()->getSymbolAddress(getRawDataRefImpl()); 383 } 384 385 inline uint64_t SymbolRef::getValue() const { 386 return getObject()->getSymbolValue(getRawDataRefImpl()); 387 } 388 389 inline uint32_t SymbolRef::getAlignment() const { 390 return getObject()->getSymbolAlignment(getRawDataRefImpl()); 391 } 392 393 inline uint64_t SymbolRef::getCommonSize() const { 394 return getObject()->getCommonSymbolSize(getRawDataRefImpl()); 395 } 396 397 inline Expected<section_iterator> SymbolRef::getSection() const { 398 return getObject()->getSymbolSection(getRawDataRefImpl()); 399 } 400 401 inline Expected<SymbolRef::Type> SymbolRef::getType() const { 402 return getObject()->getSymbolType(getRawDataRefImpl()); 403 } 404 405 inline const ObjectFile *SymbolRef::getObject() const { 406 const SymbolicFile *O = BasicSymbolRef::getObject(); 407 return cast<ObjectFile>(O); 408 } 409 410 /// SectionRef 411 inline SectionRef::SectionRef(DataRefImpl SectionP, 412 const ObjectFile *Owner) 413 : SectionPimpl(SectionP) 414 , OwningObject(Owner) {} 415 416 inline bool SectionRef::operator==(const SectionRef &Other) const { 417 return OwningObject == Other.OwningObject && 418 SectionPimpl == Other.SectionPimpl; 419 } 420 421 inline bool SectionRef::operator!=(const SectionRef &Other) const { 422 return !(*this == Other); 423 } 424 425 inline bool SectionRef::operator<(const SectionRef &Other) const { 426 assert(OwningObject == Other.OwningObject); 427 return SectionPimpl < Other.SectionPimpl; 428 } 429 430 inline void SectionRef::moveNext() { 431 return OwningObject->moveSectionNext(SectionPimpl); 432 } 433 434 inline Expected<StringRef> SectionRef::getName() const { 435 return OwningObject->getSectionName(SectionPimpl); 436 } 437 438 inline uint64_t SectionRef::getAddress() const { 439 return OwningObject->getSectionAddress(SectionPimpl); 440 } 441 442 inline uint64_t SectionRef::getIndex() const { 443 return OwningObject->getSectionIndex(SectionPimpl); 444 } 445 446 inline uint64_t SectionRef::getSize() const { 447 return OwningObject->getSectionSize(SectionPimpl); 448 } 449 450 inline Expected<StringRef> SectionRef::getContents() const { 451 Expected<ArrayRef<uint8_t>> Res = 452 OwningObject->getSectionContents(SectionPimpl); 453 if (!Res) 454 return Res.takeError(); 455 return StringRef(reinterpret_cast<const char *>(Res->data()), Res->size()); 456 } 457 458 inline uint64_t SectionRef::getAlignment() const { 459 return OwningObject->getSectionAlignment(SectionPimpl); 460 } 461 462 inline bool SectionRef::isCompressed() const { 463 return OwningObject->isSectionCompressed(SectionPimpl); 464 } 465 466 inline bool SectionRef::isText() const { 467 return OwningObject->isSectionText(SectionPimpl); 468 } 469 470 inline bool SectionRef::isData() const { 471 return OwningObject->isSectionData(SectionPimpl); 472 } 473 474 inline bool SectionRef::isBSS() const { 475 return OwningObject->isSectionBSS(SectionPimpl); 476 } 477 478 inline bool SectionRef::isVirtual() const { 479 return OwningObject->isSectionVirtual(SectionPimpl); 480 } 481 482 inline bool SectionRef::isBitcode() const { 483 return OwningObject->isSectionBitcode(SectionPimpl); 484 } 485 486 inline bool SectionRef::isStripped() const { 487 return OwningObject->isSectionStripped(SectionPimpl); 488 } 489 490 inline bool SectionRef::isBerkeleyText() const { 491 return OwningObject->isBerkeleyText(SectionPimpl); 492 } 493 494 inline bool SectionRef::isBerkeleyData() const { 495 return OwningObject->isBerkeleyData(SectionPimpl); 496 } 497 498 inline relocation_iterator SectionRef::relocation_begin() const { 499 return OwningObject->section_rel_begin(SectionPimpl); 500 } 501 502 inline relocation_iterator SectionRef::relocation_end() const { 503 return OwningObject->section_rel_end(SectionPimpl); 504 } 505 506 inline Expected<section_iterator> SectionRef::getRelocatedSection() const { 507 return OwningObject->getRelocatedSection(SectionPimpl); 508 } 509 510 inline DataRefImpl SectionRef::getRawDataRefImpl() const { 511 return SectionPimpl; 512 } 513 514 inline const ObjectFile *SectionRef::getObject() const { 515 return OwningObject; 516 } 517 518 /// RelocationRef 519 inline RelocationRef::RelocationRef(DataRefImpl RelocationP, 520 const ObjectFile *Owner) 521 : RelocationPimpl(RelocationP) 522 , OwningObject(Owner) {} 523 524 inline bool RelocationRef::operator==(const RelocationRef &Other) const { 525 return RelocationPimpl == Other.RelocationPimpl; 526 } 527 528 inline void RelocationRef::moveNext() { 529 return OwningObject->moveRelocationNext(RelocationPimpl); 530 } 531 532 inline uint64_t RelocationRef::getOffset() const { 533 return OwningObject->getRelocationOffset(RelocationPimpl); 534 } 535 536 inline symbol_iterator RelocationRef::getSymbol() const { 537 return OwningObject->getRelocationSymbol(RelocationPimpl); 538 } 539 540 inline uint64_t RelocationRef::getType() const { 541 return OwningObject->getRelocationType(RelocationPimpl); 542 } 543 544 inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const { 545 return OwningObject->getRelocationTypeName(RelocationPimpl, Result); 546 } 547 548 inline DataRefImpl RelocationRef::getRawDataRefImpl() const { 549 return RelocationPimpl; 550 } 551 552 inline const ObjectFile *RelocationRef::getObject() const { 553 return OwningObject; 554 } 555 556 } // end namespace object 557 558 template <> struct DenseMapInfo<object::SectionRef> { 559 static bool isEqual(const object::SectionRef &A, 560 const object::SectionRef &B) { 561 return A == B; 562 } 563 static object::SectionRef getEmptyKey() { 564 return object::SectionRef({}, nullptr); 565 } 566 static object::SectionRef getTombstoneKey() { 567 object::DataRefImpl TS; 568 TS.p = (uintptr_t)-1; 569 return object::SectionRef(TS, nullptr); 570 } 571 static unsigned getHashValue(const object::SectionRef &Sec) { 572 object::DataRefImpl Raw = Sec.getRawDataRefImpl(); 573 return hash_combine(Raw.p, Raw.d.a, Raw.d.b); 574 } 575 }; 576 577 } // end namespace llvm 578 579 #endif // LLVM_OBJECT_OBJECTFILE_H 580