ObjectFile.h revision ac241fe9f0d73c6f632e4f7f89e06b698d39da54 
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_OBJECT_FILE_H
15#define LLVM_OBJECT_OBJECT_FILE_H
16
17#include "llvm/Object/Binary.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/Support/MemoryBuffer.h"
22#include <cstring>
23
24namespace llvm {
25namespace object {
26
27class ObjectFile;
28
29union DataRefImpl {
30  struct {
31    uint32_t a, b;
32  } d;
33  uintptr_t p;
34};
35
36static bool operator ==(const DataRefImpl &a, const DataRefImpl &b) {
37  // Check bitwise identical. This is the only legal way to compare a union w/o
38  // knowing which member is in use.
39  return std::memcmp(&a, &b, sizeof(DataRefImpl)) == 0;
40}
41
42/// SymbolRef - This is a value type class that represents a single symbol in
43/// the list of symbols in the object file.
44class SymbolRef {
45  friend class SectionRef;
46  DataRefImpl SymbolPimpl;
47  const ObjectFile *OwningObject;
48
49public:
50  SymbolRef() : OwningObject(NULL) {
51    std::memset(&SymbolPimpl, 0, sizeof(SymbolPimpl));
52  }
53
54  enum SymbolType {
55    ST_Function,
56    ST_Data,
57    ST_External,    // Defined in another object file
58    ST_Other
59  };
60
61  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
62
63  bool operator==(const SymbolRef &Other) const;
64
65  error_code getNext(SymbolRef &Result) const;
66
67  error_code getName(StringRef &Result) const;
68  error_code getAddress(uint64_t &Result) const;
69  error_code getOffset(uint64_t &Result) const;
70  error_code getSize(uint64_t &Result) const;
71  error_code getSymbolType(SymbolRef::SymbolType &Result) const;
72
73  /// Returns the ascii char that should be displayed in a symbol table dump via
74  /// nm for this symbol.
75  error_code getNMTypeChar(char &Result) const;
76
77  /// Returns true for symbols that are internal to the object file format such
78  /// as section symbols.
79  error_code isInternal(bool &Result) const;
80
81  /// Returns true for symbols that can be used in another objects,
82  /// such as library functions
83  error_code isGlobal(bool &Result) const;
84};
85
86/// RelocationRef - This is a value type class that represents a single
87/// relocation in the list of relocations in the object file.
88class RelocationRef {
89  DataRefImpl RelocationPimpl;
90  const ObjectFile *OwningObject;
91
92public:
93  RelocationRef() : OwningObject(NULL) {
94    std::memset(&RelocationPimpl, 0, sizeof(RelocationPimpl));
95  }
96
97  RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
98
99  bool operator==(const RelocationRef &Other) const;
100
101  error_code getNext(RelocationRef &Result) const;
102
103  error_code getAddress(uint64_t &Result) const;
104  error_code getSymbol(SymbolRef &Result) const;
105  error_code getType(uint32_t &Result) const;
106  error_code getAdditionalInfo(int64_t &Result) const;
107};
108
109/// SectionRef - This is a value type class that represents a single section in
110/// the list of sections in the object file.
111class SectionRef {
112  friend class SymbolRef;
113  DataRefImpl SectionPimpl;
114  const ObjectFile *OwningObject;
115
116public:
117  SectionRef() : OwningObject(NULL) {
118    std::memset(&SectionPimpl, 0, sizeof(SectionPimpl));
119  }
120
121  SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
122
123  bool operator==(const SectionRef &Other) const;
124
125  error_code getNext(SectionRef &Result) const;
126
127  error_code getName(StringRef &Result) const;
128  error_code getAddress(uint64_t &Result) const;
129  error_code getSize(uint64_t &Result) const;
130  error_code getContents(StringRef &Result) const;
131
132  // FIXME: Move to the normalization layer when it's created.
133  error_code isText(bool &Result) const;
134
135  error_code containsSymbol(SymbolRef S, bool &Result) const;
136};
137
138const uint64_t UnknownAddressOrSize = ~0ULL;
139
140/// ObjectFile - This class is the base class for all object file types.
141/// Concrete instances of this object are created by createObjectFile, which
142/// figure out which type to create.
143class ObjectFile : public Binary {
144private:
145  ObjectFile(); // = delete
146  ObjectFile(const ObjectFile &other); // = delete
147
148protected:
149  ObjectFile(unsigned int Type, MemoryBuffer *source, error_code &ec);
150
151  const uint8_t *base() const {
152    return reinterpret_cast<const uint8_t *>(Data->getBufferStart());
153  }
154
155  // These functions are for SymbolRef to call internally. The main goal of
156  // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
157  // entry in the memory mapped object file. SymbolPimpl cannot contain any
158  // virtual functions because then it could not point into the memory mapped
159  // file.
160  //
161  // Implementations assume that the DataRefImpl is valid and has not been
162  // modified externally. It's UB otherwise.
163  friend class SymbolRef;
164  virtual error_code getSymbolNext(DataRefImpl Symb, SymbolRef &Res) const = 0;
165  virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const = 0;
166  virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const =0;
167  virtual error_code getSymbolOffset(DataRefImpl Symb, uint64_t &Res) const =0;
168  virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const = 0;
169  virtual error_code getSymbolNMTypeChar(DataRefImpl Symb, char &Res) const = 0;
170  virtual error_code isSymbolInternal(DataRefImpl Symb, bool &Res) const = 0;
171  virtual error_code isSymbolGlobal(DataRefImpl Symb, bool &Res) const = 0;
172  virtual error_code getSymbolType(DataRefImpl Symb, SymbolRef::SymbolType &Res) const = 0;
173
174  // Same as above for SectionRef.
175  friend class SectionRef;
176  virtual error_code getSectionNext(DataRefImpl Sec, SectionRef &Res) const = 0;
177  virtual error_code getSectionName(DataRefImpl Sec, StringRef &Res) const = 0;
178  virtual error_code getSectionAddress(DataRefImpl Sec, uint64_t &Res) const =0;
179  virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const = 0;
180  virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res)const=0;
181  virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const = 0;
182  virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
183                                           bool &Result) const = 0;
184
185
186  // Same as above for RelocationRef.
187  friend class RelocationRef;
188  virtual error_code getRelocationNext(DataRefImpl Rel,
189                                       RelocationRef &Res) const = 0;
190  virtual error_code getRelocationAddress(DataRefImpl Rel,
191                                          uint64_t &Res) const =0;
192  virtual error_code getRelocationSymbol(DataRefImpl Rel,
193                                         SymbolRef &Res) const = 0;
194  virtual error_code getRelocationType(DataRefImpl Rel,
195                                       uint32_t &Res) const = 0;
196  virtual error_code getRelocationAdditionalInfo(DataRefImpl Rel,
197                                                 int64_t &Res) const = 0;
198
199public:
200  template<class content_type>
201  class content_iterator {
202    content_type Current;
203  public:
204    content_iterator(content_type symb)
205      : Current(symb) {}
206
207    const content_type* operator->() const {
208      return &Current;
209    }
210
211    const content_type &operator*() const {
212      return Current;
213    }
214
215    bool operator==(const content_iterator &other) const {
216      return Current == other.Current;
217    }
218
219    bool operator!=(const content_iterator &other) const {
220      return !(*this == other);
221    }
222
223    content_iterator& increment(error_code &err) {
224      content_type next;
225      if (error_code ec = Current.getNext(next))
226        err = ec;
227      else
228        Current = next;
229      return *this;
230    }
231  };
232
233  typedef content_iterator<SymbolRef> symbol_iterator;
234  typedef content_iterator<SectionRef> section_iterator;
235  typedef content_iterator<RelocationRef> relocation_iterator;
236
237  virtual symbol_iterator begin_symbols() const = 0;
238  virtual symbol_iterator end_symbols() const = 0;
239
240  virtual section_iterator begin_sections() const = 0;
241  virtual section_iterator end_sections() const = 0;
242
243  virtual relocation_iterator begin_relocations() const = 0;
244  virtual relocation_iterator end_relocations() const = 0;
245
246  /// @brief The number of bytes used to represent an address in this object
247  ///        file format.
248  virtual uint8_t getBytesInAddress() const = 0;
249
250  virtual StringRef getFileFormatName() const = 0;
251  virtual /* Triple::ArchType */ unsigned getArch() const = 0;
252
253  /// @returns Pointer to ObjectFile subclass to handle this type of object.
254  /// @param ObjectPath The path to the object file. ObjectPath.isObject must
255  ///        return true.
256  /// @brief Create ObjectFile from path.
257  static ObjectFile *createObjectFile(StringRef ObjectPath);
258  static ObjectFile *createObjectFile(MemoryBuffer *Object);
259
260  static inline bool classof(const Binary *v) {
261    return v->getType() >= isObject &&
262           v->getType() < lastObject;
263  }
264  static inline bool classof(const ObjectFile *v) { return true; }
265
266public:
267  static ObjectFile *createCOFFObjectFile(MemoryBuffer *Object);
268  static ObjectFile *createELFObjectFile(MemoryBuffer *Object);
269  static ObjectFile *createMachOObjectFile(MemoryBuffer *Object);
270};
271
272// Inline function definitions.
273inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
274  : SymbolPimpl(SymbolP)
275  , OwningObject(Owner) {}
276
277inline bool SymbolRef::operator==(const SymbolRef &Other) const {
278  return SymbolPimpl == Other.SymbolPimpl;
279}
280
281inline error_code SymbolRef::getNext(SymbolRef &Result) const {
282  return OwningObject->getSymbolNext(SymbolPimpl, Result);
283}
284
285inline error_code SymbolRef::getName(StringRef &Result) const {
286  return OwningObject->getSymbolName(SymbolPimpl, Result);
287}
288
289inline error_code SymbolRef::getAddress(uint64_t &Result) const {
290  return OwningObject->getSymbolAddress(SymbolPimpl, Result);
291}
292
293inline error_code SymbolRef::getOffset(uint64_t &Result) const {
294  return OwningObject->getSymbolOffset(SymbolPimpl, Result);
295}
296
297inline error_code SymbolRef::getSize(uint64_t &Result) const {
298  return OwningObject->getSymbolSize(SymbolPimpl, Result);
299}
300
301inline error_code SymbolRef::getNMTypeChar(char &Result) const {
302  return OwningObject->getSymbolNMTypeChar(SymbolPimpl, Result);
303}
304
305inline error_code SymbolRef::isInternal(bool &Result) const {
306  return OwningObject->isSymbolInternal(SymbolPimpl, Result);
307}
308
309inline error_code SymbolRef::isGlobal(bool &Result) const {
310  return OwningObject->isSymbolGlobal(SymbolPimpl, Result);
311}
312
313inline error_code SymbolRef::getSymbolType(SymbolRef::SymbolType &Result) const {
314  return OwningObject->getSymbolType(SymbolPimpl, Result);
315}
316
317
318/// SectionRef
319inline SectionRef::SectionRef(DataRefImpl SectionP,
320                              const ObjectFile *Owner)
321  : SectionPimpl(SectionP)
322  , OwningObject(Owner) {}
323
324inline bool SectionRef::operator==(const SectionRef &Other) const {
325  return SectionPimpl == Other.SectionPimpl;
326}
327
328inline error_code SectionRef::getNext(SectionRef &Result) const {
329  return OwningObject->getSectionNext(SectionPimpl, Result);
330}
331
332inline error_code SectionRef::getName(StringRef &Result) const {
333  return OwningObject->getSectionName(SectionPimpl, Result);
334}
335
336inline error_code SectionRef::getAddress(uint64_t &Result) const {
337  return OwningObject->getSectionAddress(SectionPimpl, Result);
338}
339
340inline error_code SectionRef::getSize(uint64_t &Result) const {
341  return OwningObject->getSectionSize(SectionPimpl, Result);
342}
343
344inline error_code SectionRef::getContents(StringRef &Result) const {
345  return OwningObject->getSectionContents(SectionPimpl, Result);
346}
347
348inline error_code SectionRef::isText(bool &Result) const {
349  return OwningObject->isSectionText(SectionPimpl, Result);
350}
351
352inline error_code SectionRef::containsSymbol(SymbolRef S, bool &Result) const {
353  return OwningObject->sectionContainsSymbol(SectionPimpl, S.SymbolPimpl,
354                                             Result);
355}
356
357
358/// RelocationRef
359inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
360                              const ObjectFile *Owner)
361  : RelocationPimpl(RelocationP)
362  , OwningObject(Owner) {}
363
364inline bool RelocationRef::operator==(const RelocationRef &Other) const {
365  return RelocationPimpl == Other.RelocationPimpl;
366}
367
368inline error_code RelocationRef::getNext(RelocationRef &Result) const {
369  return OwningObject->getRelocationNext(RelocationPimpl, Result);
370}
371
372inline error_code RelocationRef::getAddress(uint64_t &Result) const {
373  return OwningObject->getRelocationAddress(RelocationPimpl, Result);
374}
375
376inline error_code RelocationRef::getSymbol(SymbolRef &Result) const {
377  return OwningObject->getRelocationSymbol(RelocationPimpl, Result);
378}
379
380inline error_code RelocationRef::getType(uint32_t &Result) const {
381  return OwningObject->getRelocationType(RelocationPimpl, Result);
382}
383
384inline error_code RelocationRef::getAdditionalInfo(int64_t &Result) const {
385  return OwningObject->getRelocationAdditionalInfo(RelocationPimpl, Result);
386}
387
388} // end namespace object
389} // end namespace llvm
390
391#endif
392