ObjectFile.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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/Object/SymbolicFile.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/Support/FileSystem.h"
22#include "llvm/Support/MemoryBuffer.h"
23#include <cstring>
24#include <vector>
25
26namespace llvm {
27namespace object {
28
29class ObjectFile;
30
31class SymbolRef;
32class symbol_iterator;
33
34/// RelocationRef - This is a value type class that represents a single
35/// relocation in the list of relocations in the object file.
36class RelocationRef {
37  DataRefImpl RelocationPimpl;
38  const ObjectFile *OwningObject;
39
40public:
41  RelocationRef() : OwningObject(nullptr) { }
42
43  RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
44
45  bool operator==(const RelocationRef &Other) const;
46
47  void moveNext();
48
49  error_code getAddress(uint64_t &Result) const;
50  error_code getOffset(uint64_t &Result) const;
51  symbol_iterator getSymbol() const;
52  error_code getType(uint64_t &Result) const;
53
54  /// @brief Indicates whether this relocation should hidden when listing
55  /// relocations, usually because it is the trailing part of a multipart
56  /// relocation that will be printed as part of the leading relocation.
57  error_code getHidden(bool &Result) const;
58
59  /// @brief Get a string that represents the type of this relocation.
60  ///
61  /// This is for display purposes only.
62  error_code getTypeName(SmallVectorImpl<char> &Result) const;
63
64  /// @brief Get a string that represents the calculation of the value of this
65  ///        relocation.
66  ///
67  /// This is for display purposes only.
68  error_code getValueString(SmallVectorImpl<char> &Result) const;
69
70  DataRefImpl getRawDataRefImpl() const;
71  const ObjectFile *getObjectFile() const;
72};
73typedef content_iterator<RelocationRef> relocation_iterator;
74
75/// SectionRef - This is a value type class that represents a single section in
76/// the list of sections in the object file.
77class SectionRef;
78typedef content_iterator<SectionRef> section_iterator;
79class SectionRef {
80  friend class SymbolRef;
81  DataRefImpl SectionPimpl;
82  const ObjectFile *OwningObject;
83
84public:
85  SectionRef() : OwningObject(nullptr) { }
86
87  SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
88
89  bool operator==(const SectionRef &Other) const;
90  bool operator!=(const SectionRef &Other) const;
91  bool operator<(const SectionRef &Other) const;
92
93  void moveNext();
94
95  error_code getName(StringRef &Result) const;
96  error_code getAddress(uint64_t &Result) const;
97  error_code getSize(uint64_t &Result) const;
98  error_code getContents(StringRef &Result) const;
99
100  /// @brief Get the alignment of this section as the actual value (not log 2).
101  error_code getAlignment(uint64_t &Result) const;
102
103  // FIXME: Move to the normalization layer when it's created.
104  error_code isText(bool &Result) const;
105  error_code isData(bool &Result) const;
106  error_code isBSS(bool &Result) const;
107  error_code isRequiredForExecution(bool &Result) const;
108  error_code isVirtual(bool &Result) const;
109  error_code isZeroInit(bool &Result) const;
110  error_code isReadOnlyData(bool &Result) const;
111
112  error_code containsSymbol(SymbolRef S, bool &Result) const;
113
114  relocation_iterator relocation_begin() const;
115  relocation_iterator relocation_end() const;
116  iterator_range<relocation_iterator> relocations() const {
117    return iterator_range<relocation_iterator>(relocation_begin(),
118                                               relocation_end());
119  }
120  section_iterator getRelocatedSection() const;
121
122  DataRefImpl getRawDataRefImpl() const;
123};
124
125/// SymbolRef - This is a value type class that represents a single symbol in
126/// the list of symbols in the object file.
127class SymbolRef : public BasicSymbolRef {
128  friend class SectionRef;
129
130public:
131  SymbolRef() : BasicSymbolRef() {}
132
133  enum Type {
134    ST_Unknown, // Type not specified
135    ST_Data,
136    ST_Debug,
137    ST_File,
138    ST_Function,
139    ST_Other
140  };
141
142  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
143
144  error_code getName(StringRef &Result) const;
145  /// Returns the symbol virtual address (i.e. address at which it will be
146  /// mapped).
147  error_code getAddress(uint64_t &Result) const;
148  /// @brief Get the alignment of this symbol as the actual value (not log 2).
149  error_code getAlignment(uint32_t &Result) const;
150  error_code getSize(uint64_t &Result) const;
151  error_code getType(SymbolRef::Type &Result) const;
152
153  /// @brief Get section this symbol is defined in reference to. Result is
154  /// end_sections() if it is undefined or is an absolute symbol.
155  error_code getSection(section_iterator &Result) const;
156
157  const ObjectFile *getObject() const;
158};
159
160class symbol_iterator : public basic_symbol_iterator {
161public:
162  symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
163  symbol_iterator(const basic_symbol_iterator &B)
164      : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
165                                        cast<ObjectFile>(B->getObject()))) {}
166
167  const SymbolRef *operator->() const {
168    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
169    return static_cast<const SymbolRef*>(&P);
170  }
171
172  const SymbolRef &operator*() const {
173    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
174    return static_cast<const SymbolRef&>(P);
175  }
176};
177
178/// LibraryRef - This is a value type class that represents a single library in
179/// the list of libraries needed by a shared or dynamic object.
180class LibraryRef {
181  friend class SectionRef;
182  DataRefImpl LibraryPimpl;
183  const ObjectFile *OwningObject;
184
185public:
186  LibraryRef() : OwningObject(nullptr) { }
187
188  LibraryRef(DataRefImpl LibraryP, const ObjectFile *Owner);
189
190  bool operator==(const LibraryRef &Other) const;
191  bool operator<(const LibraryRef &Other) const;
192
193  error_code getNext(LibraryRef &Result) const;
194
195  // Get the path to this library, as stored in the object file.
196  error_code getPath(StringRef &Result) const;
197
198  DataRefImpl getRawDataRefImpl() const;
199};
200typedef content_iterator<LibraryRef> library_iterator;
201
202/// ObjectFile - This class is the base class for all object file types.
203/// Concrete instances of this object are created by createObjectFile, which
204/// figures out which type to create.
205class ObjectFile : public SymbolicFile {
206  virtual void anchor();
207  ObjectFile() LLVM_DELETED_FUNCTION;
208  ObjectFile(const ObjectFile &other) LLVM_DELETED_FUNCTION;
209
210protected:
211  ObjectFile(unsigned int Type, MemoryBuffer *Source, bool BufferOwned = true);
212
213  const uint8_t *base() const {
214    return reinterpret_cast<const uint8_t *>(Data->getBufferStart());
215  }
216
217  // These functions are for SymbolRef to call internally. The main goal of
218  // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
219  // entry in the memory mapped object file. SymbolPimpl cannot contain any
220  // virtual functions because then it could not point into the memory mapped
221  // file.
222  //
223  // Implementations assume that the DataRefImpl is valid and has not been
224  // modified externally. It's UB otherwise.
225  friend class SymbolRef;
226  virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const = 0;
227  error_code printSymbolName(raw_ostream &OS, DataRefImpl Symb) const override;
228  virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const = 0;
229  virtual error_code getSymbolAlignment(DataRefImpl Symb, uint32_t &Res) const;
230  virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const = 0;
231  virtual error_code getSymbolType(DataRefImpl Symb,
232                                   SymbolRef::Type &Res) const = 0;
233  virtual error_code getSymbolSection(DataRefImpl Symb,
234                                      section_iterator &Res) const = 0;
235
236  // Same as above for SectionRef.
237  friend class SectionRef;
238  virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
239  virtual error_code getSectionName(DataRefImpl Sec, StringRef &Res) const = 0;
240  virtual error_code getSectionAddress(DataRefImpl Sec, uint64_t &Res) const =0;
241  virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const = 0;
242  virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res)const=0;
243  virtual error_code getSectionAlignment(DataRefImpl Sec, uint64_t &Res)const=0;
244  virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const = 0;
245  virtual error_code isSectionData(DataRefImpl Sec, bool &Res) const = 0;
246  virtual error_code isSectionBSS(DataRefImpl Sec, bool &Res) const = 0;
247  virtual error_code isSectionRequiredForExecution(DataRefImpl Sec,
248                                                   bool &Res) const = 0;
249  // A section is 'virtual' if its contents aren't present in the object image.
250  virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const = 0;
251  virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const = 0;
252  virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const =0;
253  virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
254                                           bool &Result) const = 0;
255  virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
256  virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
257  virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
258
259  // Same as above for RelocationRef.
260  friend class RelocationRef;
261  virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
262  virtual error_code getRelocationAddress(DataRefImpl Rel,
263                                          uint64_t &Res) const =0;
264  virtual error_code getRelocationOffset(DataRefImpl Rel,
265                                         uint64_t &Res) const =0;
266  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
267  virtual error_code getRelocationType(DataRefImpl Rel,
268                                       uint64_t &Res) const = 0;
269  virtual error_code getRelocationTypeName(DataRefImpl Rel,
270                                       SmallVectorImpl<char> &Result) const = 0;
271  virtual error_code getRelocationValueString(DataRefImpl Rel,
272                                       SmallVectorImpl<char> &Result) const = 0;
273  virtual error_code getRelocationHidden(DataRefImpl Rel, bool &Result) const {
274    Result = false;
275    return object_error::success;
276  }
277
278  // Same for LibraryRef
279  friend class LibraryRef;
280  virtual error_code getLibraryNext(DataRefImpl Lib, LibraryRef &Res) const = 0;
281  virtual error_code getLibraryPath(DataRefImpl Lib, StringRef &Res) const = 0;
282
283public:
284  typedef iterator_range<symbol_iterator> symbol_iterator_range;
285  symbol_iterator_range symbols() const {
286    return symbol_iterator_range(symbol_begin(), symbol_end());
287  }
288
289  virtual section_iterator section_begin() const = 0;
290  virtual section_iterator section_end() const = 0;
291
292  typedef iterator_range<section_iterator> section_iterator_range;
293  section_iterator_range sections() const {
294    return section_iterator_range(section_begin(), section_end());
295  }
296
297  virtual library_iterator needed_library_begin() const = 0;
298  virtual library_iterator needed_library_end() const = 0;
299
300  /// @brief The number of bytes used to represent an address in this object
301  ///        file format.
302  virtual uint8_t getBytesInAddress() const = 0;
303
304  virtual StringRef getFileFormatName() const = 0;
305  virtual /* Triple::ArchType */ unsigned getArch() const = 0;
306
307  /// For shared objects, returns the name which this object should be
308  /// loaded from at runtime. This corresponds to DT_SONAME on ELF and
309  /// LC_ID_DYLIB (install name) on MachO.
310  virtual StringRef getLoadName() const = 0;
311
312  /// @returns Pointer to ObjectFile subclass to handle this type of object.
313  /// @param ObjectPath The path to the object file. ObjectPath.isObject must
314  ///        return true.
315  /// @brief Create ObjectFile from path.
316  static ErrorOr<ObjectFile *> createObjectFile(StringRef ObjectPath);
317  static ErrorOr<ObjectFile *> createObjectFile(MemoryBuffer *Object,
318                                                bool BufferOwned,
319                                                sys::fs::file_magic Type);
320  static ErrorOr<ObjectFile *> createObjectFile(MemoryBuffer *Object) {
321    return createObjectFile(Object, true, sys::fs::file_magic::unknown);
322  }
323
324
325  static inline bool classof(const Binary *v) {
326    return v->isObject();
327  }
328
329public:
330  static ErrorOr<ObjectFile *> createCOFFObjectFile(MemoryBuffer *Object,
331                                                    bool BufferOwned = true);
332  static ErrorOr<ObjectFile *> createELFObjectFile(MemoryBuffer *Object,
333                                                   bool BufferOwned = true);
334  static ErrorOr<ObjectFile *> createMachOObjectFile(MemoryBuffer *Object,
335                                                     bool BufferOwned = true);
336};
337
338// Inline function definitions.
339inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
340    : BasicSymbolRef(SymbolP, Owner) {}
341
342inline error_code SymbolRef::getName(StringRef &Result) const {
343  return getObject()->getSymbolName(getRawDataRefImpl(), Result);
344}
345
346inline error_code SymbolRef::getAddress(uint64_t &Result) const {
347  return getObject()->getSymbolAddress(getRawDataRefImpl(), Result);
348}
349
350inline error_code SymbolRef::getAlignment(uint32_t &Result) const {
351  return getObject()->getSymbolAlignment(getRawDataRefImpl(), Result);
352}
353
354inline error_code SymbolRef::getSize(uint64_t &Result) const {
355  return getObject()->getSymbolSize(getRawDataRefImpl(), Result);
356}
357
358inline error_code SymbolRef::getSection(section_iterator &Result) const {
359  return getObject()->getSymbolSection(getRawDataRefImpl(), Result);
360}
361
362inline error_code SymbolRef::getType(SymbolRef::Type &Result) const {
363  return getObject()->getSymbolType(getRawDataRefImpl(), Result);
364}
365
366inline const ObjectFile *SymbolRef::getObject() const {
367  const SymbolicFile *O = BasicSymbolRef::getObject();
368  return cast<ObjectFile>(O);
369}
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 error_code SectionRef::getName(StringRef &Result) const {
395  return OwningObject->getSectionName(SectionPimpl, Result);
396}
397
398inline error_code SectionRef::getAddress(uint64_t &Result) const {
399  return OwningObject->getSectionAddress(SectionPimpl, Result);
400}
401
402inline error_code SectionRef::getSize(uint64_t &Result) const {
403  return OwningObject->getSectionSize(SectionPimpl, Result);
404}
405
406inline error_code SectionRef::getContents(StringRef &Result) const {
407  return OwningObject->getSectionContents(SectionPimpl, Result);
408}
409
410inline error_code SectionRef::getAlignment(uint64_t &Result) const {
411  return OwningObject->getSectionAlignment(SectionPimpl, Result);
412}
413
414inline error_code SectionRef::isText(bool &Result) const {
415  return OwningObject->isSectionText(SectionPimpl, Result);
416}
417
418inline error_code SectionRef::isData(bool &Result) const {
419  return OwningObject->isSectionData(SectionPimpl, Result);
420}
421
422inline error_code SectionRef::isBSS(bool &Result) const {
423  return OwningObject->isSectionBSS(SectionPimpl, Result);
424}
425
426inline error_code SectionRef::isRequiredForExecution(bool &Result) const {
427  return OwningObject->isSectionRequiredForExecution(SectionPimpl, Result);
428}
429
430inline error_code SectionRef::isVirtual(bool &Result) const {
431  return OwningObject->isSectionVirtual(SectionPimpl, Result);
432}
433
434inline error_code SectionRef::isZeroInit(bool &Result) const {
435  return OwningObject->isSectionZeroInit(SectionPimpl, Result);
436}
437
438inline error_code SectionRef::isReadOnlyData(bool &Result) const {
439  return OwningObject->isSectionReadOnlyData(SectionPimpl, Result);
440}
441
442inline error_code SectionRef::containsSymbol(SymbolRef S, bool &Result) const {
443  return OwningObject->sectionContainsSymbol(SectionPimpl,
444                                             S.getRawDataRefImpl(), Result);
445}
446
447inline relocation_iterator SectionRef::relocation_begin() const {
448  return OwningObject->section_rel_begin(SectionPimpl);
449}
450
451inline relocation_iterator SectionRef::relocation_end() const {
452  return OwningObject->section_rel_end(SectionPimpl);
453}
454
455inline section_iterator SectionRef::getRelocatedSection() const {
456  return OwningObject->getRelocatedSection(SectionPimpl);
457}
458
459inline DataRefImpl SectionRef::getRawDataRefImpl() const {
460  return SectionPimpl;
461}
462
463/// RelocationRef
464inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
465                              const ObjectFile *Owner)
466  : RelocationPimpl(RelocationP)
467  , OwningObject(Owner) {}
468
469inline bool RelocationRef::operator==(const RelocationRef &Other) const {
470  return RelocationPimpl == Other.RelocationPimpl;
471}
472
473inline void RelocationRef::moveNext() {
474  return OwningObject->moveRelocationNext(RelocationPimpl);
475}
476
477inline error_code RelocationRef::getAddress(uint64_t &Result) const {
478  return OwningObject->getRelocationAddress(RelocationPimpl, Result);
479}
480
481inline error_code RelocationRef::getOffset(uint64_t &Result) const {
482  return OwningObject->getRelocationOffset(RelocationPimpl, Result);
483}
484
485inline symbol_iterator RelocationRef::getSymbol() const {
486  return OwningObject->getRelocationSymbol(RelocationPimpl);
487}
488
489inline error_code RelocationRef::getType(uint64_t &Result) const {
490  return OwningObject->getRelocationType(RelocationPimpl, Result);
491}
492
493inline error_code RelocationRef::getTypeName(SmallVectorImpl<char> &Result)
494  const {
495  return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
496}
497
498inline error_code RelocationRef::getValueString(SmallVectorImpl<char> &Result)
499  const {
500  return OwningObject->getRelocationValueString(RelocationPimpl, Result);
501}
502
503inline error_code RelocationRef::getHidden(bool &Result) const {
504  return OwningObject->getRelocationHidden(RelocationPimpl, Result);
505}
506
507inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
508  return RelocationPimpl;
509}
510
511inline const ObjectFile *RelocationRef::getObjectFile() const {
512  return OwningObject;
513}
514
515// Inline function definitions.
516inline LibraryRef::LibraryRef(DataRefImpl LibraryP, const ObjectFile *Owner)
517  : LibraryPimpl(LibraryP)
518  , OwningObject(Owner) {}
519
520inline bool LibraryRef::operator==(const LibraryRef &Other) const {
521  return LibraryPimpl == Other.LibraryPimpl;
522}
523
524inline bool LibraryRef::operator<(const LibraryRef &Other) const {
525  return LibraryPimpl < Other.LibraryPimpl;
526}
527
528inline error_code LibraryRef::getNext(LibraryRef &Result) const {
529  return OwningObject->getLibraryNext(LibraryPimpl, Result);
530}
531
532inline error_code LibraryRef::getPath(StringRef &Result) const {
533  return OwningObject->getLibraryPath(LibraryPimpl, Result);
534}
535
536} // end namespace object
537} // end namespace llvm
538
539#endif
540