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;
30class COFFObjectFile;
31class MachOObjectFile;
32
33class SymbolRef;
34class symbol_iterator;
35class SectionRef;
36typedef content_iterator<SectionRef> section_iterator;
37
38/// This is a value type class that represents a single relocation in the list
39/// of relocations in the object file.
40class RelocationRef {
41  DataRefImpl RelocationPimpl;
42  const ObjectFile *OwningObject;
43
44public:
45  RelocationRef() : OwningObject(nullptr) { }
46
47  RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
48
49  bool operator==(const RelocationRef &Other) const;
50
51  void moveNext();
52
53  uint64_t getOffset() const;
54  symbol_iterator getSymbol() const;
55  uint64_t getType() const;
56
57  /// @brief Get a string that represents the type of this relocation.
58  ///
59  /// This is for display purposes only.
60  void getTypeName(SmallVectorImpl<char> &Result) const;
61
62  DataRefImpl getRawDataRefImpl() const;
63  const ObjectFile *getObject() const;
64};
65typedef content_iterator<RelocationRef> relocation_iterator;
66
67/// This is a value type class that represents a single section in the list of
68/// sections in the object file.
69class SectionRef {
70  friend class SymbolRef;
71  DataRefImpl SectionPimpl;
72  const ObjectFile *OwningObject;
73
74public:
75  SectionRef() : OwningObject(nullptr) { }
76
77  SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
78
79  bool operator==(const SectionRef &Other) const;
80  bool operator!=(const SectionRef &Other) const;
81  bool operator<(const SectionRef &Other) const;
82
83  void moveNext();
84
85  std::error_code getName(StringRef &Result) const;
86  uint64_t getAddress() const;
87  uint64_t getSize() const;
88  std::error_code getContents(StringRef &Result) const;
89
90  /// @brief Get the alignment of this section as the actual value (not log 2).
91  uint64_t getAlignment() const;
92
93  bool isText() const;
94  bool isData() const;
95  bool isBSS() const;
96  bool isVirtual() const;
97
98  bool containsSymbol(SymbolRef S) const;
99
100  relocation_iterator relocation_begin() const;
101  relocation_iterator relocation_end() const;
102  iterator_range<relocation_iterator> relocations() const {
103    return make_range(relocation_begin(), relocation_end());
104  }
105  section_iterator getRelocatedSection() const;
106
107  DataRefImpl getRawDataRefImpl() const;
108  const ObjectFile *getObject() const;
109};
110
111/// This is a value type class that represents a single symbol in the list of
112/// symbols in the object file.
113class SymbolRef : public BasicSymbolRef {
114  friend class SectionRef;
115
116public:
117  SymbolRef() : BasicSymbolRef() {}
118
119  enum Type {
120    ST_Unknown, // Type not specified
121    ST_Data,
122    ST_Debug,
123    ST_File,
124    ST_Function,
125    ST_Other
126  };
127
128  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
129  SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
130    assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
131  }
132
133  ErrorOr<StringRef> getName() const;
134  /// Returns the symbol virtual address (i.e. address at which it will be
135  /// mapped).
136  ErrorOr<uint64_t> getAddress() const;
137
138  /// Return the value of the symbol depending on the object this can be an
139  /// offset or a virtual address.
140  uint64_t getValue() const;
141
142  /// @brief Get the alignment of this symbol as the actual value (not log 2).
143  uint32_t getAlignment() const;
144  uint64_t getCommonSize() const;
145  SymbolRef::Type getType() const;
146
147  /// @brief Get section this symbol is defined in reference to. Result is
148  /// end_sections() if it is undefined or is an absolute symbol.
149  ErrorOr<section_iterator> getSection() const;
150
151  const ObjectFile *getObject() const;
152};
153
154class symbol_iterator : public basic_symbol_iterator {
155public:
156  symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
157  symbol_iterator(const basic_symbol_iterator &B)
158      : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
159                                        cast<ObjectFile>(B->getObject()))) {}
160
161  const SymbolRef *operator->() const {
162    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
163    return static_cast<const SymbolRef*>(&P);
164  }
165
166  const SymbolRef &operator*() const {
167    const BasicSymbolRef &P = basic_symbol_iterator::operator *();
168    return static_cast<const SymbolRef&>(P);
169  }
170};
171
172/// This class is the base class for all object file types. Concrete instances
173/// of this object are created by createObjectFile, which figures out which type
174/// to create.
175class ObjectFile : public SymbolicFile {
176  virtual void anchor();
177  ObjectFile() = delete;
178  ObjectFile(const ObjectFile &other) = delete;
179
180protected:
181  ObjectFile(unsigned int Type, MemoryBufferRef Source);
182
183  const uint8_t *base() const {
184    return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
185  }
186
187  // These functions are for SymbolRef to call internally. The main goal of
188  // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
189  // entry in the memory mapped object file. SymbolPimpl cannot contain any
190  // virtual functions because then it could not point into the memory mapped
191  // file.
192  //
193  // Implementations assume that the DataRefImpl is valid and has not been
194  // modified externally. It's UB otherwise.
195  friend class SymbolRef;
196  virtual ErrorOr<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
197  std::error_code printSymbolName(raw_ostream &OS,
198                                  DataRefImpl Symb) const override;
199  virtual ErrorOr<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
200  virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
201  virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
202  virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
203  virtual SymbolRef::Type getSymbolType(DataRefImpl Symb) const = 0;
204  virtual ErrorOr<section_iterator>
205  getSymbolSection(DataRefImpl Symb) const = 0;
206
207  // Same as above for SectionRef.
208  friend class SectionRef;
209  virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
210  virtual std::error_code getSectionName(DataRefImpl Sec,
211                                         StringRef &Res) const = 0;
212  virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
213  virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
214  virtual std::error_code getSectionContents(DataRefImpl Sec,
215                                             StringRef &Res) const = 0;
216  virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
217  virtual bool isSectionText(DataRefImpl Sec) const = 0;
218  virtual bool isSectionData(DataRefImpl Sec) const = 0;
219  virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
220  // A section is 'virtual' if its contents aren't present in the object image.
221  virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
222  virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
223  virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
224  virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
225
226  // Same as above for RelocationRef.
227  friend class RelocationRef;
228  virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
229  virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
230  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
231  virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
232  virtual void getRelocationTypeName(DataRefImpl Rel,
233                                     SmallVectorImpl<char> &Result) const = 0;
234
235  uint64_t getSymbolValue(DataRefImpl Symb) const;
236
237public:
238  uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
239    assert(getSymbolFlags(Symb) & SymbolRef::SF_Common);
240    return getCommonSymbolSizeImpl(Symb);
241  }
242
243  typedef iterator_range<symbol_iterator> symbol_iterator_range;
244  symbol_iterator_range symbols() const {
245    return symbol_iterator_range(symbol_begin(), symbol_end());
246  }
247
248  virtual section_iterator section_begin() const = 0;
249  virtual section_iterator section_end() const = 0;
250
251  typedef iterator_range<section_iterator> section_iterator_range;
252  section_iterator_range sections() const {
253    return section_iterator_range(section_begin(), section_end());
254  }
255
256  /// @brief The number of bytes used to represent an address in this object
257  ///        file format.
258  virtual uint8_t getBytesInAddress() const = 0;
259
260  virtual StringRef getFileFormatName() const = 0;
261  virtual /* Triple::ArchType */ unsigned getArch() const = 0;
262
263  /// Returns platform-specific object flags, if any.
264  virtual std::error_code getPlatformFlags(unsigned &Result) const {
265    Result = 0;
266    return object_error::invalid_file_type;
267  }
268
269  /// True if this is a relocatable object (.o/.obj).
270  virtual bool isRelocatableObject() const = 0;
271
272  /// @returns Pointer to ObjectFile subclass to handle this type of object.
273  /// @param ObjectPath The path to the object file. ObjectPath.isObject must
274  ///        return true.
275  /// @brief Create ObjectFile from path.
276  static ErrorOr<OwningBinary<ObjectFile>>
277  createObjectFile(StringRef ObjectPath);
278
279  static ErrorOr<std::unique_ptr<ObjectFile>>
280  createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type);
281  static ErrorOr<std::unique_ptr<ObjectFile>>
282  createObjectFile(MemoryBufferRef Object) {
283    return createObjectFile(Object, sys::fs::file_magic::unknown);
284  }
285
286
287  static inline bool classof(const Binary *v) {
288    return v->isObject();
289  }
290
291  static ErrorOr<std::unique_ptr<COFFObjectFile>>
292  createCOFFObjectFile(MemoryBufferRef Object);
293
294  static ErrorOr<std::unique_ptr<ObjectFile>>
295  createELFObjectFile(MemoryBufferRef Object);
296
297  static ErrorOr<std::unique_ptr<MachOObjectFile>>
298  createMachOObjectFile(MemoryBufferRef Object);
299};
300
301// Inline function definitions.
302inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
303    : BasicSymbolRef(SymbolP, Owner) {}
304
305inline ErrorOr<StringRef> SymbolRef::getName() const {
306  return getObject()->getSymbolName(getRawDataRefImpl());
307}
308
309inline ErrorOr<uint64_t> SymbolRef::getAddress() const {
310  return getObject()->getSymbolAddress(getRawDataRefImpl());
311}
312
313inline uint64_t SymbolRef::getValue() const {
314  return getObject()->getSymbolValue(getRawDataRefImpl());
315}
316
317inline uint32_t SymbolRef::getAlignment() const {
318  return getObject()->getSymbolAlignment(getRawDataRefImpl());
319}
320
321inline uint64_t SymbolRef::getCommonSize() const {
322  return getObject()->getCommonSymbolSize(getRawDataRefImpl());
323}
324
325inline ErrorOr<section_iterator> SymbolRef::getSection() const {
326  return getObject()->getSymbolSection(getRawDataRefImpl());
327}
328
329inline SymbolRef::Type SymbolRef::getType() const {
330  return getObject()->getSymbolType(getRawDataRefImpl());
331}
332
333inline const ObjectFile *SymbolRef::getObject() const {
334  const SymbolicFile *O = BasicSymbolRef::getObject();
335  return cast<ObjectFile>(O);
336}
337
338
339/// SectionRef
340inline SectionRef::SectionRef(DataRefImpl SectionP,
341                              const ObjectFile *Owner)
342  : SectionPimpl(SectionP)
343  , OwningObject(Owner) {}
344
345inline bool SectionRef::operator==(const SectionRef &Other) const {
346  return SectionPimpl == Other.SectionPimpl;
347}
348
349inline bool SectionRef::operator!=(const SectionRef &Other) const {
350  return SectionPimpl != Other.SectionPimpl;
351}
352
353inline bool SectionRef::operator<(const SectionRef &Other) const {
354  return SectionPimpl < Other.SectionPimpl;
355}
356
357inline void SectionRef::moveNext() {
358  return OwningObject->moveSectionNext(SectionPimpl);
359}
360
361inline std::error_code SectionRef::getName(StringRef &Result) const {
362  return OwningObject->getSectionName(SectionPimpl, Result);
363}
364
365inline uint64_t SectionRef::getAddress() const {
366  return OwningObject->getSectionAddress(SectionPimpl);
367}
368
369inline uint64_t SectionRef::getSize() const {
370  return OwningObject->getSectionSize(SectionPimpl);
371}
372
373inline std::error_code SectionRef::getContents(StringRef &Result) const {
374  return OwningObject->getSectionContents(SectionPimpl, Result);
375}
376
377inline uint64_t SectionRef::getAlignment() const {
378  return OwningObject->getSectionAlignment(SectionPimpl);
379}
380
381inline bool SectionRef::isText() const {
382  return OwningObject->isSectionText(SectionPimpl);
383}
384
385inline bool SectionRef::isData() const {
386  return OwningObject->isSectionData(SectionPimpl);
387}
388
389inline bool SectionRef::isBSS() const {
390  return OwningObject->isSectionBSS(SectionPimpl);
391}
392
393inline bool SectionRef::isVirtual() const {
394  return OwningObject->isSectionVirtual(SectionPimpl);
395}
396
397inline relocation_iterator SectionRef::relocation_begin() const {
398  return OwningObject->section_rel_begin(SectionPimpl);
399}
400
401inline relocation_iterator SectionRef::relocation_end() const {
402  return OwningObject->section_rel_end(SectionPimpl);
403}
404
405inline section_iterator SectionRef::getRelocatedSection() const {
406  return OwningObject->getRelocatedSection(SectionPimpl);
407}
408
409inline DataRefImpl SectionRef::getRawDataRefImpl() const {
410  return SectionPimpl;
411}
412
413inline const ObjectFile *SectionRef::getObject() const {
414  return OwningObject;
415}
416
417/// RelocationRef
418inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
419                              const ObjectFile *Owner)
420  : RelocationPimpl(RelocationP)
421  , OwningObject(Owner) {}
422
423inline bool RelocationRef::operator==(const RelocationRef &Other) const {
424  return RelocationPimpl == Other.RelocationPimpl;
425}
426
427inline void RelocationRef::moveNext() {
428  return OwningObject->moveRelocationNext(RelocationPimpl);
429}
430
431inline uint64_t RelocationRef::getOffset() const {
432  return OwningObject->getRelocationOffset(RelocationPimpl);
433}
434
435inline symbol_iterator RelocationRef::getSymbol() const {
436  return OwningObject->getRelocationSymbol(RelocationPimpl);
437}
438
439inline uint64_t RelocationRef::getType() const {
440  return OwningObject->getRelocationType(RelocationPimpl);
441}
442
443inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
444  return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
445}
446
447inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
448  return RelocationPimpl;
449}
450
451inline const ObjectFile *RelocationRef::getObject() const {
452  return OwningObject;
453}
454
455
456} // end namespace object
457} // end namespace llvm
458
459#endif
460