1//===- ObjectFile.h - File format independent object file -------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file declares a file format independent ObjectFile class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_OBJECT_OBJECTFILE_H
15#define LLVM_OBJECT_OBJECTFILE_H
16
17#include "llvm/ADT/StringRef.h"
18#include "llvm/ADT/iterator_range.h"
19#include "llvm/BinaryFormat/Magic.h"
20#include "llvm/MC/SubtargetFeature.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/ErrorOr.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
34namespace llvm {
35
36class ARMAttributeParser;
37
38namespace object {
39
40class COFFObjectFile;
41class MachOObjectFile;
42class ObjectFile;
43class SectionRef;
44class SymbolRef;
45class symbol_iterator;
46class WasmObjectFile;
47
48using 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.
52class RelocationRef {
53  DataRefImpl RelocationPimpl;
54  const ObjectFile *OwningObject = nullptr;
55
56public:
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  /// @brief 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
77using 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.
81class SectionRef {
82  friend class SymbolRef;
83
84  DataRefImpl SectionPimpl;
85  const ObjectFile *OwningObject = nullptr;
86
87public:
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  std::error_code getName(StringRef &Result) const;
98  uint64_t getAddress() const;
99  uint64_t getIndex() const;
100  uint64_t getSize() const;
101  std::error_code getContents(StringRef &Result) const;
102
103  /// @brief Get the alignment of this section as the actual value (not log 2).
104  uint64_t getAlignment() const;
105
106  bool isCompressed() const;
107  bool isText() const;
108  bool isData() const;
109  bool isBSS() const;
110  bool isVirtual() const;
111  bool isBitcode() const;
112
113  bool containsSymbol(SymbolRef S) const;
114
115  relocation_iterator relocation_begin() const;
116  relocation_iterator relocation_end() const;
117  iterator_range<relocation_iterator> relocations() const {
118    return make_range(relocation_begin(), relocation_end());
119  }
120  section_iterator getRelocatedSection() const;
121
122  DataRefImpl getRawDataRefImpl() const;
123  const ObjectFile *getObject() const;
124};
125
126/// This is a value type class that represents a single symbol in the list of
127/// symbols in the object file.
128class SymbolRef : public BasicSymbolRef {
129  friend class SectionRef;
130
131public:
132  enum Type {
133    ST_Unknown, // Type not specified
134    ST_Data,
135    ST_Debug,
136    ST_File,
137    ST_Function,
138    ST_Other
139  };
140
141  SymbolRef() = default;
142  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
143  SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
144    assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
145  }
146
147  Expected<StringRef> getName() const;
148  /// Returns the symbol virtual address (i.e. address at which it will be
149  /// mapped).
150  Expected<uint64_t> getAddress() const;
151
152  /// Return the value of the symbol depending on the object this can be an
153  /// offset or a virtual address.
154  uint64_t getValue() const;
155
156  /// @brief Get the alignment of this symbol as the actual value (not log 2).
157  uint32_t getAlignment() const;
158  uint64_t getCommonSize() const;
159  Expected<SymbolRef::Type> getType() const;
160
161  /// @brief Get section this symbol is defined in reference to. Result is
162  /// end_sections() if it is undefined or is an absolute symbol.
163  Expected<section_iterator> getSection() const;
164
165  const ObjectFile *getObject() const;
166};
167
168class symbol_iterator : public basic_symbol_iterator {
169public:
170  symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
171  symbol_iterator(const basic_symbol_iterator &B)
172      : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
173                                        cast<ObjectFile>(B->getObject()))) {}
174
175  const SymbolRef *operator->() const {
176    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
177    return static_cast<const SymbolRef*>(&P);
178  }
179
180  const SymbolRef &operator*() const {
181    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
182    return static_cast<const SymbolRef&>(P);
183  }
184};
185
186/// This class is the base class for all object file types. Concrete instances
187/// of this object are created by createObjectFile, which figures out which type
188/// to create.
189class ObjectFile : public SymbolicFile {
190  virtual void anchor();
191
192protected:
193  ObjectFile(unsigned int Type, MemoryBufferRef Source);
194
195  const uint8_t *base() const {
196    return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
197  }
198
199  // These functions are for SymbolRef to call internally. The main goal of
200  // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
201  // entry in the memory mapped object file. SymbolPimpl cannot contain any
202  // virtual functions because then it could not point into the memory mapped
203  // file.
204  //
205  // Implementations assume that the DataRefImpl is valid and has not been
206  // modified externally. It's UB otherwise.
207  friend class SymbolRef;
208
209  virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
210  std::error_code printSymbolName(raw_ostream &OS,
211                                  DataRefImpl Symb) const override;
212  virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
213  virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
214  virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
215  virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
216  virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0;
217  virtual Expected<section_iterator>
218  getSymbolSection(DataRefImpl Symb) const = 0;
219
220  // Same as above for SectionRef.
221  friend class SectionRef;
222
223  virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
224  virtual std::error_code getSectionName(DataRefImpl Sec,
225                                         StringRef &Res) const = 0;
226  virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
227  virtual uint64_t getSectionIndex(DataRefImpl Sec) const = 0;
228  virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
229  virtual std::error_code getSectionContents(DataRefImpl Sec,
230                                             StringRef &Res) const = 0;
231  virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
232  virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
233  virtual bool isSectionText(DataRefImpl Sec) const = 0;
234  virtual bool isSectionData(DataRefImpl Sec) const = 0;
235  virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
236  // A section is 'virtual' if its contents aren't present in the object image.
237  virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
238  virtual bool isSectionBitcode(DataRefImpl Sec) const;
239  virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
240  virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
241  virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
242
243  // Same as above for RelocationRef.
244  friend class RelocationRef;
245  virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
246  virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
247  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
248  virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
249  virtual void getRelocationTypeName(DataRefImpl Rel,
250                                     SmallVectorImpl<char> &Result) const = 0;
251
252  uint64_t getSymbolValue(DataRefImpl Symb) const;
253
254public:
255  ObjectFile() = delete;
256  ObjectFile(const ObjectFile &other) = delete;
257
258  uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
259    assert(getSymbolFlags(Symb) & SymbolRef::SF_Common);
260    return getCommonSymbolSizeImpl(Symb);
261  }
262
263  using symbol_iterator_range = iterator_range<symbol_iterator>;
264  symbol_iterator_range symbols() const {
265    return symbol_iterator_range(symbol_begin(), symbol_end());
266  }
267
268  virtual section_iterator section_begin() const = 0;
269  virtual section_iterator section_end() const = 0;
270
271  using section_iterator_range = iterator_range<section_iterator>;
272  section_iterator_range sections() const {
273    return section_iterator_range(section_begin(), section_end());
274  }
275
276  /// @brief The number of bytes used to represent an address in this object
277  ///        file format.
278  virtual uint8_t getBytesInAddress() const = 0;
279
280  virtual StringRef getFileFormatName() const = 0;
281  virtual /* Triple::ArchType */ unsigned getArch() const = 0;
282  virtual SubtargetFeatures getFeatures() const = 0;
283  virtual void setARMSubArch(Triple &TheTriple) const { }
284
285  /// Returns platform-specific object flags, if any.
286  virtual std::error_code getPlatformFlags(unsigned &Result) const {
287    Result = 0;
288    return object_error::invalid_file_type;
289  }
290
291  virtual std::error_code
292    getBuildAttributes(ARMAttributeParser &Attributes) const {
293      return std::error_code();
294    }
295
296  /// Maps a debug section name to a standard DWARF section name.
297  virtual StringRef mapDebugSectionName(StringRef Name) const { return Name; }
298
299  /// True if this is a relocatable object (.o/.obj).
300  virtual bool isRelocatableObject() const = 0;
301
302  /// @returns Pointer to ObjectFile subclass to handle this type of object.
303  /// @param ObjectPath The path to the object file. ObjectPath.isObject must
304  ///        return true.
305  /// @brief Create ObjectFile from path.
306  static Expected<OwningBinary<ObjectFile>>
307  createObjectFile(StringRef ObjectPath);
308
309  static Expected<std::unique_ptr<ObjectFile>>
310  createObjectFile(MemoryBufferRef Object, llvm::file_magic Type);
311  static Expected<std::unique_ptr<ObjectFile>>
312  createObjectFile(MemoryBufferRef Object) {
313    return createObjectFile(Object, llvm::file_magic::unknown);
314  }
315
316  static inline bool classof(const Binary *v) {
317    return v->isObject();
318  }
319
320  static ErrorOr<std::unique_ptr<COFFObjectFile>>
321  createCOFFObjectFile(MemoryBufferRef Object);
322
323  static ErrorOr<std::unique_ptr<ObjectFile>>
324  createELFObjectFile(MemoryBufferRef Object);
325
326  static Expected<std::unique_ptr<MachOObjectFile>>
327  createMachOObjectFile(MemoryBufferRef Object,
328                        uint32_t UniversalCputype = 0,
329                        uint32_t UniversalIndex = 0);
330
331  static Expected<std::unique_ptr<WasmObjectFile>>
332  createWasmObjectFile(MemoryBufferRef Object);
333};
334
335// Inline function definitions.
336inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
337    : BasicSymbolRef(SymbolP, Owner) {}
338
339inline Expected<StringRef> SymbolRef::getName() const {
340  return getObject()->getSymbolName(getRawDataRefImpl());
341}
342
343inline Expected<uint64_t> SymbolRef::getAddress() const {
344  return getObject()->getSymbolAddress(getRawDataRefImpl());
345}
346
347inline uint64_t SymbolRef::getValue() const {
348  return getObject()->getSymbolValue(getRawDataRefImpl());
349}
350
351inline uint32_t SymbolRef::getAlignment() const {
352  return getObject()->getSymbolAlignment(getRawDataRefImpl());
353}
354
355inline uint64_t SymbolRef::getCommonSize() const {
356  return getObject()->getCommonSymbolSize(getRawDataRefImpl());
357}
358
359inline Expected<section_iterator> SymbolRef::getSection() const {
360  return getObject()->getSymbolSection(getRawDataRefImpl());
361}
362
363inline Expected<SymbolRef::Type> SymbolRef::getType() const {
364  return getObject()->getSymbolType(getRawDataRefImpl());
365}
366
367inline const ObjectFile *SymbolRef::getObject() const {
368  const SymbolicFile *O = BasicSymbolRef::getObject();
369  return cast<ObjectFile>(O);
370}
371
372/// SectionRef
373inline SectionRef::SectionRef(DataRefImpl SectionP,
374                              const ObjectFile *Owner)
375  : SectionPimpl(SectionP)
376  , OwningObject(Owner) {}
377
378inline bool SectionRef::operator==(const SectionRef &Other) const {
379  return SectionPimpl == Other.SectionPimpl;
380}
381
382inline bool SectionRef::operator!=(const SectionRef &Other) const {
383  return SectionPimpl != Other.SectionPimpl;
384}
385
386inline bool SectionRef::operator<(const SectionRef &Other) const {
387  return SectionPimpl < Other.SectionPimpl;
388}
389
390inline void SectionRef::moveNext() {
391  return OwningObject->moveSectionNext(SectionPimpl);
392}
393
394inline std::error_code SectionRef::getName(StringRef &Result) const {
395  return OwningObject->getSectionName(SectionPimpl, Result);
396}
397
398inline uint64_t SectionRef::getAddress() const {
399  return OwningObject->getSectionAddress(SectionPimpl);
400}
401
402inline uint64_t SectionRef::getIndex() const {
403  return OwningObject->getSectionIndex(SectionPimpl);
404}
405
406inline uint64_t SectionRef::getSize() const {
407  return OwningObject->getSectionSize(SectionPimpl);
408}
409
410inline std::error_code SectionRef::getContents(StringRef &Result) const {
411  return OwningObject->getSectionContents(SectionPimpl, Result);
412}
413
414inline uint64_t SectionRef::getAlignment() const {
415  return OwningObject->getSectionAlignment(SectionPimpl);
416}
417
418inline bool SectionRef::isCompressed() const {
419  return OwningObject->isSectionCompressed(SectionPimpl);
420}
421
422inline bool SectionRef::isText() const {
423  return OwningObject->isSectionText(SectionPimpl);
424}
425
426inline bool SectionRef::isData() const {
427  return OwningObject->isSectionData(SectionPimpl);
428}
429
430inline bool SectionRef::isBSS() const {
431  return OwningObject->isSectionBSS(SectionPimpl);
432}
433
434inline bool SectionRef::isVirtual() const {
435  return OwningObject->isSectionVirtual(SectionPimpl);
436}
437
438inline bool SectionRef::isBitcode() const {
439  return OwningObject->isSectionBitcode(SectionPimpl);
440}
441
442inline relocation_iterator SectionRef::relocation_begin() const {
443  return OwningObject->section_rel_begin(SectionPimpl);
444}
445
446inline relocation_iterator SectionRef::relocation_end() const {
447  return OwningObject->section_rel_end(SectionPimpl);
448}
449
450inline section_iterator SectionRef::getRelocatedSection() const {
451  return OwningObject->getRelocatedSection(SectionPimpl);
452}
453
454inline DataRefImpl SectionRef::getRawDataRefImpl() const {
455  return SectionPimpl;
456}
457
458inline const ObjectFile *SectionRef::getObject() const {
459  return OwningObject;
460}
461
462/// RelocationRef
463inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
464                              const ObjectFile *Owner)
465  : RelocationPimpl(RelocationP)
466  , OwningObject(Owner) {}
467
468inline bool RelocationRef::operator==(const RelocationRef &Other) const {
469  return RelocationPimpl == Other.RelocationPimpl;
470}
471
472inline void RelocationRef::moveNext() {
473  return OwningObject->moveRelocationNext(RelocationPimpl);
474}
475
476inline uint64_t RelocationRef::getOffset() const {
477  return OwningObject->getRelocationOffset(RelocationPimpl);
478}
479
480inline symbol_iterator RelocationRef::getSymbol() const {
481  return OwningObject->getRelocationSymbol(RelocationPimpl);
482}
483
484inline uint64_t RelocationRef::getType() const {
485  return OwningObject->getRelocationType(RelocationPimpl);
486}
487
488inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
489  return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
490}
491
492inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
493  return RelocationPimpl;
494}
495
496inline const ObjectFile *RelocationRef::getObject() const {
497  return OwningObject;
498}
499
500} // end namespace object
501
502} // end namespace llvm
503
504#endif // LLVM_OBJECT_OBJECTFILE_H
505