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/Object/Binary.h"
22#include "llvm/Object/Error.h"
23#include "llvm/Object/SymbolicFile.h"
24#include "llvm/Support/Casting.h"
25#include "llvm/Support/Error.h"
26#include "llvm/Support/MemoryBuffer.h"
27#include <cassert>
28#include <cstdint>
29#include <memory>
30#include <system_error>
31
32namespace llvm {
33
34class ARMAttributeParser;
35class SubtargetFeatures;
36
37namespace object {
38
39class COFFObjectFile;
40class MachOObjectFile;
41class ObjectFile;
42class SectionRef;
43class SymbolRef;
44class symbol_iterator;
45class WasmObjectFile;
46
47using section_iterator = content_iterator<SectionRef>;
48
49/// This is a value type class that represents a single relocation in the list
50/// of relocations in the object file.
51class RelocationRef {
52 DataRefImpl RelocationPimpl;
53 const ObjectFile *OwningObject = nullptr;
54
55public:
56 RelocationRef() = default;
57 RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
58
59 bool operator==(const RelocationRef &Other) const;
60
61 void moveNext();
62
63 uint64_t getOffset() const;
64 symbol_iterator getSymbol() const;
65 uint64_t getType() const;
66
67 /// Get a string that represents the type of this relocation.
68 ///
69 /// This is for display purposes only.
70 void getTypeName(SmallVectorImpl<char> &Result) const;
71
72 DataRefImpl getRawDataRefImpl() const;
73 const ObjectFile *getObject() const;
74};
75
76using relocation_iterator = content_iterator<RelocationRef>;
77
78/// This is a value type class that represents a single section in the list of
79/// sections in the object file.
80class SectionRef {
81 friend class SymbolRef;
82
83 DataRefImpl SectionPimpl;
84 const ObjectFile *OwningObject = nullptr;
85
86public:
87 SectionRef() = default;
88 SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
89
90 bool operator==(const SectionRef &Other) const;
91 bool operator!=(const SectionRef &Other) const;
92 bool operator<(const SectionRef &Other) const;
93
94 void moveNext();
95
96 Expected<StringRef> getName() const;
97 uint64_t getAddress() const;
98 uint64_t getIndex() const;
99 uint64_t getSize() const;
100 Expected<StringRef> getContents() const;
101
102 /// Get the alignment of this section as the actual value (not log 2).
103 uint64_t getAlignment() const;
104
105 bool isCompressed() const;
106 /// Whether this section contains instructions.
107 bool isText() const;
108 /// Whether this section contains data, not instructions.
109 bool isData() const;
110 /// Whether this section contains BSS uninitialized data.
111 bool isBSS() const;
112 bool isVirtual() const;
113 bool isBitcode() const;
114 bool isStripped() const;
115
116 /// Whether this section will be placed in the text segment, according to the
117 /// Berkeley size format. This is true if the section is allocatable, and
118 /// contains either code or readonly data.
119 bool isBerkeleyText() const;
120 /// Whether this section will be placed in the data segment, according to the
121 /// Berkeley size format. This is true if the section is allocatable and
122 /// contains data (e.g. PROGBITS), but is not text.
123 bool isBerkeleyData() const;
124
125 /// Whether this section is a debug section.
126 bool isDebugSection(StringRef SectionName) const;
127
128 bool containsSymbol(SymbolRef S) const;
129
130 relocation_iterator relocation_begin() const;
131 relocation_iterator relocation_end() const;
132 iterator_range<relocation_iterator> relocations() const {
133 return make_range(relocation_begin(), relocation_end());
134 }
135 Expected<section_iterator> getRelocatedSection() const;
136
137 DataRefImpl getRawDataRefImpl() const;
138 const ObjectFile *getObject() const;
139};
140
141struct SectionedAddress {
142 const static uint64_t UndefSection = UINT64_MAX;
143
144 uint64_t Address = 0;
145 uint64_t SectionIndex = UndefSection;
146};
147
148inline bool operator<(const SectionedAddress &LHS,
149 const SectionedAddress &RHS) {
150 return std::tie(LHS.SectionIndex, LHS.Address) <
151 std::tie(RHS.SectionIndex, RHS.Address);
152}
153
154inline bool operator==(const SectionedAddress &LHS,
155 const SectionedAddress &RHS) {
156 return std::tie(LHS.SectionIndex, LHS.Address) ==
157 std::tie(RHS.SectionIndex, RHS.Address);
158}
159
160raw_ostream &operator<<(raw_ostream &OS, const SectionedAddress &Addr);
161
162/// This is a value type class that represents a single symbol in the list of
163/// symbols in the object file.
164class SymbolRef : public BasicSymbolRef {
165 friend class SectionRef;
166
167public:
168 enum Type {
169 ST_Unknown, // Type not specified
170 ST_Data,
171 ST_Debug,
172 ST_File,
173 ST_Function,
174 ST_Other
175 };
176
177 SymbolRef() = default;
178 SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
179 SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
180 assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
181 }
182
183 Expected<StringRef> getName() const;
184 /// Returns the symbol virtual address (i.e. address at which it will be
185 /// mapped).
186 Expected<uint64_t> getAddress() const;
187
188 /// Return the value of the symbol depending on the object this can be an
189 /// offset or a virtual address.
190 Expected<uint64_t> getValue() const;
191
192 /// Get the alignment of this symbol as the actual value (not log 2).
193 uint32_t getAlignment() const;
194 uint64_t getCommonSize() const;
195 Expected<SymbolRef::Type> getType() const;
196
197 /// Get section this symbol is defined in reference to. Result is
198 /// end_sections() if it is undefined or is an absolute symbol.
199 Expected<section_iterator> getSection() const;
200
201 const ObjectFile *getObject() const;
202};
203
204class symbol_iterator : public basic_symbol_iterator {
205public:
206 symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
207 symbol_iterator(const basic_symbol_iterator &B)
208 : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
209 cast<ObjectFile>(B->getObject()))) {}
210
211 const SymbolRef *operator->() const {
212 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
213 return static_cast<const SymbolRef*>(&P);
214 }
215
216 const SymbolRef &operator*() const {
217 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
218 return static_cast<const SymbolRef&>(P);
219 }
220};
221
222/// This class is the base class for all object file types. Concrete instances
223/// of this object are created by createObjectFile, which figures out which type
224/// to create.
225class ObjectFile : public SymbolicFile {
226 virtual void anchor();
227
228protected:
229 ObjectFile(unsigned int Type, MemoryBufferRef Source);
230
231 const uint8_t *base() const {
232 return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
233 }
234
235 // These functions are for SymbolRef to call internally. The main goal of
236 // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
237 // entry in the memory mapped object file. SymbolPimpl cannot contain any
238 // virtual functions because then it could not point into the memory mapped
239 // file.
240 //
241 // Implementations assume that the DataRefImpl is valid and has not been
242 // modified externally. It's UB otherwise.
243 friend class SymbolRef;
244
245 virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
246 Error printSymbolName(raw_ostream &OS,
247 DataRefImpl Symb) const override;
248 virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
249 virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
250 virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
251 virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
252 virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0;
253 virtual Expected<section_iterator>
254 getSymbolSection(DataRefImpl Symb) const = 0;
255
256 // Same as above for SectionRef.
257 friend class SectionRef;
258
259 virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
260 virtual Expected<StringRef> getSectionName(DataRefImpl Sec) const = 0;
261 virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
262 virtual uint64_t getSectionIndex(DataRefImpl Sec) const = 0;
263 virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
264 virtual Expected<ArrayRef<uint8_t>>
265 getSectionContents(DataRefImpl Sec) const = 0;
266 virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
267 virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
268 virtual bool isSectionText(DataRefImpl Sec) const = 0;
269 virtual bool isSectionData(DataRefImpl Sec) const = 0;
270 virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
271 // A section is 'virtual' if its contents aren't present in the object image.
272 virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
273 virtual bool isSectionBitcode(DataRefImpl Sec) const;
274 virtual bool isSectionStripped(DataRefImpl Sec) const;
275 virtual bool isBerkeleyText(DataRefImpl Sec) const;
276 virtual bool isBerkeleyData(DataRefImpl Sec) const;
277 virtual bool isDebugSection(StringRef SectionName) const;
278 virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
279 virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
280 virtual Expected<section_iterator> getRelocatedSection(DataRefImpl Sec) const;
281
282 // Same as above for RelocationRef.
283 friend class RelocationRef;
284 virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
285 virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
286 virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
287 virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
288 virtual void getRelocationTypeName(DataRefImpl Rel,
289 SmallVectorImpl<char> &Result) const = 0;
290
291 Expected<uint64_t> getSymbolValue(DataRefImpl Symb) const;
292
293public:
294 ObjectFile() = delete;
295 ObjectFile(const ObjectFile &other) = delete;
296
297 uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
298 Expected<uint32_t> SymbolFlagsOrErr = getSymbolFlags(Symb);
299 if (!SymbolFlagsOrErr)
300 // TODO: Actually report errors helpfully.
301 report_fatal_error(SymbolFlagsOrErr.takeError());
302 assert(*SymbolFlagsOrErr & SymbolRef::SF_Common);
303 return getCommonSymbolSizeImpl(Symb);
304 }
305
306 virtual std::vector<SectionRef> dynamic_relocation_sections() const {
307 return std::vector<SectionRef>();
308 }
309
310 using symbol_iterator_range = iterator_range<symbol_iterator>;
311 symbol_iterator_range symbols() const {
312 return symbol_iterator_range(symbol_begin(), symbol_end());
313 }
314
315 virtual section_iterator section_begin() const = 0;
316 virtual section_iterator section_end() const = 0;
317
318 using section_iterator_range = iterator_range<section_iterator>;
319 section_iterator_range sections() const {
320 return section_iterator_range(section_begin(), section_end());
321 }
322
323 /// The number of bytes used to represent an address in this object
324 /// file format.
325 virtual uint8_t getBytesInAddress() const = 0;
326
327 virtual StringRef getFileFormatName() const = 0;
328 virtual Triple::ArchType getArch() const = 0;
329 virtual SubtargetFeatures getFeatures() const = 0;
330 virtual Optional<StringRef> tryGetCPUName() const { return None; };
331 virtual void setARMSubArch(Triple &TheTriple) const { }
332 virtual Expected<uint64_t> getStartAddress() const {
333 return errorCodeToError(object_error::parse_failed);
334 };
335
336 /// Create a triple from the data in this object file.
337 Triple makeTriple() const;
338
339 /// Maps a debug section name to a standard DWARF section name.
340 virtual StringRef mapDebugSectionName(StringRef Name) const { return Name; }
341
342 /// True if this is a relocatable object (.o/.obj).
343 virtual bool isRelocatableObject() const = 0;
344
345 /// @returns Pointer to ObjectFile subclass to handle this type of object.
346 /// @param ObjectPath The path to the object file. ObjectPath.isObject must
347 /// return true.
348 /// Create ObjectFile from path.
349 static Expected<OwningBinary<ObjectFile>>
350 createObjectFile(StringRef ObjectPath);
351
352 static Expected<std::unique_ptr<ObjectFile>>
353 createObjectFile(MemoryBufferRef Object, llvm::file_magic Type,
354 bool InitContent = true);
355 static Expected<std::unique_ptr<ObjectFile>>
356 createObjectFile(MemoryBufferRef Object) {
357 return createObjectFile(Object, llvm::file_magic::unknown);
358 }
359
360 static bool classof(const Binary *v) {
361 return v->isObject();
362 }
363
364 static Expected<std::unique_ptr<COFFObjectFile>>
365 createCOFFObjectFile(MemoryBufferRef Object);
366
367 static Expected<std::unique_ptr<ObjectFile>>
368 createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType);
369
370 static Expected<std::unique_ptr<ObjectFile>>
371 createELFObjectFile(MemoryBufferRef Object, bool InitContent = true);
372
373 static Expected<std::unique_ptr<MachOObjectFile>>
374 createMachOObjectFile(MemoryBufferRef Object,
375 uint32_t UniversalCputype = 0,
376 uint32_t UniversalIndex = 0);
377
378 static Expected<std::unique_ptr<WasmObjectFile>>
379 createWasmObjectFile(MemoryBufferRef Object);
380};
381
382// Inline function definitions.
383inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
384 : BasicSymbolRef(SymbolP, Owner) {}
385
386inline Expected<StringRef> SymbolRef::getName() const {
387 return getObject()->getSymbolName(getRawDataRefImpl());
388}
389
390inline Expected<uint64_t> SymbolRef::getAddress() const {
391 return getObject()->getSymbolAddress(getRawDataRefImpl());
392}
393
394inline Expected<uint64_t> SymbolRef::getValue() const {
395 return getObject()->getSymbolValue(getRawDataRefImpl());
396}
397
398inline uint32_t SymbolRef::getAlignment() const {
399 return getObject()->getSymbolAlignment(getRawDataRefImpl());
400}
401
402inline uint64_t SymbolRef::getCommonSize() const {
403 return getObject()->getCommonSymbolSize(getRawDataRefImpl());
404}
405
406inline Expected<section_iterator> SymbolRef::getSection() const {
407 return getObject()->getSymbolSection(getRawDataRefImpl());
408}
409
410inline Expected<SymbolRef::Type> SymbolRef::getType() const {
411 return getObject()->getSymbolType(getRawDataRefImpl());
412}
413
414inline const ObjectFile *SymbolRef::getObject() const {
415 const SymbolicFile *O = BasicSymbolRef::getObject();
416 return cast<ObjectFile>(O);
417}
418
419/// SectionRef
420inline SectionRef::SectionRef(DataRefImpl SectionP,
421 const ObjectFile *Owner)
422 : SectionPimpl(SectionP)
423 , OwningObject(Owner) {}
424
425inline bool SectionRef::operator==(const SectionRef &Other) const {
426 return OwningObject == Other.OwningObject &&
427 SectionPimpl == Other.SectionPimpl;
428}
429
430inline bool SectionRef::operator!=(const SectionRef &Other) const {
431 return !(*this == Other);
432}
433
434inline bool SectionRef::operator<(const SectionRef &Other) const {
435 assert(OwningObject == Other.OwningObject);
436 return SectionPimpl < Other.SectionPimpl;
437}
438
439inline void SectionRef::moveNext() {
440 return OwningObject->moveSectionNext(SectionPimpl);
441}
442
443inline Expected<StringRef> SectionRef::getName() const {
444 return OwningObject->getSectionName(SectionPimpl);
445}
446
447inline uint64_t SectionRef::getAddress() const {
448 return OwningObject->getSectionAddress(SectionPimpl);
449}
450
451inline uint64_t SectionRef::getIndex() const {
452 return OwningObject->getSectionIndex(SectionPimpl);
453}
454
455inline uint64_t SectionRef::getSize() const {
456 return OwningObject->getSectionSize(SectionPimpl);
457}
458
459inline Expected<StringRef> SectionRef::getContents() const {
460 Expected<ArrayRef<uint8_t>> Res =
461 OwningObject->getSectionContents(SectionPimpl);
462 if (!Res)
463 return Res.takeError();
464 return StringRef(reinterpret_cast<const char *>(Res->data()), Res->size());
465}
466
467inline uint64_t SectionRef::getAlignment() const {
468 return OwningObject->getSectionAlignment(SectionPimpl);
469}
470
471inline bool SectionRef::isCompressed() const {
472 return OwningObject->isSectionCompressed(SectionPimpl);
473}
474
475inline bool SectionRef::isText() const {
476 return OwningObject->isSectionText(SectionPimpl);
477}
478
479inline bool SectionRef::isData() const {
480 return OwningObject->isSectionData(SectionPimpl);
481}
482
483inline bool SectionRef::isBSS() const {
484 return OwningObject->isSectionBSS(SectionPimpl);
485}
486
487inline bool SectionRef::isVirtual() const {
488 return OwningObject->isSectionVirtual(SectionPimpl);
489}
490
491inline bool SectionRef::isBitcode() const {
492 return OwningObject->isSectionBitcode(SectionPimpl);
493}
494
495inline bool SectionRef::isStripped() const {
496 return OwningObject->isSectionStripped(SectionPimpl);
497}
498
499inline bool SectionRef::isBerkeleyText() const {
500 return OwningObject->isBerkeleyText(SectionPimpl);
501}
502
503inline bool SectionRef::isBerkeleyData() const {
504 return OwningObject->isBerkeleyData(SectionPimpl);
505}
506
507inline bool SectionRef::isDebugSection(StringRef SectionName) const {
508 return OwningObject->isDebugSection(SectionName);
509}
510
511inline relocation_iterator SectionRef::relocation_begin() const {
512 return OwningObject->section_rel_begin(SectionPimpl);
513}
514
515inline relocation_iterator SectionRef::relocation_end() const {
516 return OwningObject->section_rel_end(SectionPimpl);
517}
518
519inline Expected<section_iterator> SectionRef::getRelocatedSection() const {
520 return OwningObject->getRelocatedSection(SectionPimpl);
521}
522
523inline DataRefImpl SectionRef::getRawDataRefImpl() const {
524 return SectionPimpl;
525}
526
527inline const ObjectFile *SectionRef::getObject() const {
528 return OwningObject;
529}
530
531/// RelocationRef
532inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
533 const ObjectFile *Owner)
534 : RelocationPimpl(RelocationP)
535 , OwningObject(Owner) {}
536
537inline bool RelocationRef::operator==(const RelocationRef &Other) const {
538 return RelocationPimpl == Other.RelocationPimpl;
539}
540
541inline void RelocationRef::moveNext() {
542 return OwningObject->moveRelocationNext(RelocationPimpl);
543}
544
545inline uint64_t RelocationRef::getOffset() const {
546 return OwningObject->getRelocationOffset(RelocationPimpl);
547}
548
549inline symbol_iterator RelocationRef::getSymbol() const {
550 return OwningObject->getRelocationSymbol(RelocationPimpl);
551}
552
553inline uint64_t RelocationRef::getType() const {
554 return OwningObject->getRelocationType(RelocationPimpl);
555}
556
557inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
558 return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
559}
560
561inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
562 return RelocationPimpl;
563}
564
565inline const ObjectFile *RelocationRef::getObject() const {
566 return OwningObject;
567}
568
569} // end namespace object
570
571template <> struct DenseMapInfo<object::SectionRef> {
572 static bool isEqual(const object::SectionRef &A,
573 const object::SectionRef &B) {
574 return A == B;
575 }
576 static object::SectionRef getEmptyKey() {
577 return object::SectionRef({}, nullptr);
578 }
579 static object::SectionRef getTombstoneKey() {
580 object::DataRefImpl TS;
581 TS.p = (uintptr_t)-1;
582 return object::SectionRef(TS, nullptr);
583 }
584 static unsigned getHashValue(const object::SectionRef &Sec) {
585 object::DataRefImpl Raw = Sec.getRawDataRefImpl();
586 return hash_combine(Raw.p, Raw.d.a, Raw.d.b);
587 }
588};
589
590} // end namespace llvm
591
592#endif // LLVM_OBJECT_OBJECTFILE_H
593