ObjectFile.h revision dedd6ee135f886e219035b2cf5957ce492f90ed1 
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
42class RelocationRef {
43  DataRefImpl RelocationPimpl;
44  const ObjectFile *OwningObject;
45
46public:
47  RelocationRef() : OwningObject(NULL) {
48    std::memset(&RelocationPimpl, 0, sizeof(RelocationPimpl));
49  }
50
51  RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
52
53  bool operator==(const RelocationRef &Other) const;
54
55  error_code getNext(RelocationRef &Result);
56};
57
58/// SymbolRef - This is a value type class that represents a single symbol in
59/// the list of symbols in the object file.
60class SymbolRef {
61  DataRefImpl SymbolPimpl;
62  const ObjectFile *OwningObject;
63
64public:
65  SymbolRef() : OwningObject(NULL) {
66    std::memset(&SymbolPimpl, 0, sizeof(SymbolPimpl));
67  }
68
69  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
70
71  bool operator==(const SymbolRef &Other) const;
72
73  error_code getNext(SymbolRef &Result) const;
74
75  error_code getName(StringRef &Result) const;
76  error_code getAddress(uint64_t &Result) const;
77  error_code getSize(uint64_t &Result) const;
78
79  /// Returns the ascii char that should be displayed in a symbol table dump via
80  /// nm for this symbol.
81  error_code getNMTypeChar(char &Result) const;
82
83  /// Returns true for symbols that are internal to the object file format such
84  /// as section symbols.
85  error_code isInternal(bool &Result) const;
86};
87
88/// SectionRef - This is a value type class that represents a single section in
89/// the list of sections in the object file.
90class SectionRef {
91  DataRefImpl SectionPimpl;
92  const ObjectFile *OwningObject;
93
94public:
95  SectionRef() : OwningObject(NULL) {
96    std::memset(&SectionPimpl, 0, sizeof(SectionPimpl));
97  }
98
99  SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
100
101  bool operator==(const SectionRef &Other) const;
102
103  error_code getNext(SectionRef &Result) const;
104
105  error_code getName(StringRef &Result) const;
106  error_code getAddress(uint64_t &Result) const;
107  error_code getSize(uint64_t &Result) const;
108  error_code getContents(StringRef &Result) const;
109
110  // FIXME: Move to the normalization layer when it's created.
111  error_code isText(bool &Result) const;
112};
113
114const uint64_t UnknownAddressOrSize = ~0ULL;
115
116/// ObjectFile - This class is the base class for all object file types.
117/// Concrete instances of this object are created by createObjectFile, which
118/// figure out which type to create.
119class ObjectFile : public Binary {
120private:
121  ObjectFile(); // = delete
122  ObjectFile(const ObjectFile &other); // = delete
123
124protected:
125  ObjectFile(unsigned int Type, MemoryBuffer *source, error_code &ec);
126
127  const uint8_t *base() const {
128    return reinterpret_cast<const uint8_t *>(Data->getBufferStart());
129  }
130
131  // These functions are for SymbolRef to call internally. The main goal of
132  // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
133  // entry in the memory mapped object file. SymbolPimpl cannot contain any
134  // virtual functions because then it could not point into the memory mapped
135  // file.
136  //
137  // Implementations assume that the DataRefImpl is valid and has not been
138  // modified externally. It's UB otherwise.
139  friend class SymbolRef;
140  virtual error_code getSymbolNext(DataRefImpl Symb, SymbolRef &Res) const = 0;
141  virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const = 0;
142  virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const =0;
143  virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const = 0;
144  virtual error_code getSymbolNMTypeChar(DataRefImpl Symb, char &Res) const = 0;
145  virtual error_code isSymbolInternal(DataRefImpl Symb, bool &Res) const = 0;
146
147  // Same as above for SectionRef.
148  friend class SectionRef;
149  virtual error_code getSectionNext(DataRefImpl Sec, SectionRef &Res) const = 0;
150  virtual error_code getSectionName(DataRefImpl Sec, StringRef &Res) const = 0;
151  virtual error_code getSectionAddress(DataRefImpl Sec, uint64_t &Res) const =0;
152  virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const = 0;
153  virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res)const=0;
154  virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const = 0;
155
156
157public:
158  template<class content_type>
159  class content_iterator {
160    content_type Current;
161  public:
162    content_iterator(content_type symb)
163      : Current(symb) {}
164
165    const content_type* operator->() const {
166      return &Current;
167    }
168
169    bool operator==(const content_iterator &other) const {
170      return Current == other.Current;
171    }
172
173    bool operator!=(const content_iterator &other) const {
174      return !(*this == other);
175    }
176
177    content_iterator& increment(error_code &err) {
178      content_type next;
179      if (error_code ec = Current.getNext(next))
180        err = ec;
181      else
182        Current = next;
183      return *this;
184    }
185  };
186
187  typedef content_iterator<SymbolRef> symbol_iterator;
188  typedef content_iterator<SectionRef> section_iterator;
189
190  virtual symbol_iterator begin_symbols() const = 0;
191  virtual symbol_iterator end_symbols() const = 0;
192
193  virtual section_iterator begin_sections() const = 0;
194  virtual section_iterator end_sections() const = 0;
195
196  /// @brief The number of bytes used to represent an address in this object
197  ///        file format.
198  virtual uint8_t getBytesInAddress() const = 0;
199
200  virtual StringRef getFileFormatName() const = 0;
201  virtual /* Triple::ArchType */ unsigned getArch() const = 0;
202
203  /// @returns Pointer to ObjectFile subclass to handle this type of object.
204  /// @param ObjectPath The path to the object file. ObjectPath.isObject must
205  ///        return true.
206  /// @brief Create ObjectFile from path.
207  static ObjectFile *createObjectFile(StringRef ObjectPath);
208  static ObjectFile *createObjectFile(MemoryBuffer *Object);
209
210  static inline bool classof(const Binary *v) {
211    return v->getType() >= isObject &&
212           v->getType() < lastObject;
213  }
214  static inline bool classof(const ObjectFile *v) { return true; }
215
216public:
217  static ObjectFile *createCOFFObjectFile(MemoryBuffer *Object);
218  static ObjectFile *createELFObjectFile(MemoryBuffer *Object);
219  static ObjectFile *createMachOObjectFile(MemoryBuffer *Object);
220};
221
222// Inline function definitions.
223inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
224  : SymbolPimpl(SymbolP)
225  , OwningObject(Owner) {}
226
227inline bool SymbolRef::operator==(const SymbolRef &Other) const {
228  return SymbolPimpl == Other.SymbolPimpl;
229}
230
231inline error_code SymbolRef::getNext(SymbolRef &Result) const {
232  return OwningObject->getSymbolNext(SymbolPimpl, Result);
233}
234
235inline error_code SymbolRef::getName(StringRef &Result) const {
236  return OwningObject->getSymbolName(SymbolPimpl, Result);
237}
238
239inline error_code SymbolRef::getAddress(uint64_t &Result) const {
240  return OwningObject->getSymbolAddress(SymbolPimpl, Result);
241}
242
243inline error_code SymbolRef::getSize(uint64_t &Result) const {
244  return OwningObject->getSymbolSize(SymbolPimpl, Result);
245}
246
247inline error_code SymbolRef::getNMTypeChar(char &Result) const {
248  return OwningObject->getSymbolNMTypeChar(SymbolPimpl, Result);
249}
250
251inline error_code SymbolRef::isInternal(bool &Result) const {
252  return OwningObject->isSymbolInternal(SymbolPimpl, Result);
253}
254
255
256/// SectionRef
257inline SectionRef::SectionRef(DataRefImpl SectionP,
258                              const ObjectFile *Owner)
259  : SectionPimpl(SectionP)
260  , OwningObject(Owner) {}
261
262inline bool SectionRef::operator==(const SectionRef &Other) const {
263  return SectionPimpl == Other.SectionPimpl;
264}
265
266inline error_code SectionRef::getNext(SectionRef &Result) const {
267  return OwningObject->getSectionNext(SectionPimpl, Result);
268}
269
270inline error_code SectionRef::getName(StringRef &Result) const {
271  return OwningObject->getSectionName(SectionPimpl, Result);
272}
273
274inline error_code SectionRef::getAddress(uint64_t &Result) const {
275  return OwningObject->getSectionAddress(SectionPimpl, Result);
276}
277
278inline error_code SectionRef::getSize(uint64_t &Result) const {
279  return OwningObject->getSectionSize(SectionPimpl, Result);
280}
281
282inline error_code SectionRef::getContents(StringRef &Result) const {
283  return OwningObject->getSectionContents(SectionPimpl, Result);
284}
285
286inline error_code SectionRef::isText(bool &Result) const {
287  return OwningObject->isSectionText(SectionPimpl, Result);
288}
289
290} // end namespace object
291} // end namespace llvm
292
293#endif
294