1//===- Archive.h - ar archive file format -----------------------*- 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 the ar archive file format class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_OBJECT_ARCHIVE_H
15#define LLVM_OBJECT_ARCHIVE_H
16
17#include "llvm/ADT/Optional.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/ADT/iterator_range.h"
20#include "llvm/Object/Binary.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/ErrorOr.h"
23#include "llvm/Support/FileSystem.h"
24#include "llvm/Support/MemoryBuffer.h"
25
26namespace llvm {
27namespace object {
28struct ArchiveMemberHeader {
29  char Name[16];
30  char LastModified[12];
31  char UID[6];
32  char GID[6];
33  char AccessMode[8];
34  char Size[10]; ///< Size of data, not including header or padding.
35  char Terminator[2];
36
37  /// Get the name without looking up long names.
38  llvm::StringRef getName() const;
39
40  /// Members are not larger than 4GB.
41  ErrorOr<uint32_t> getSize() const;
42
43  sys::fs::perms getAccessMode() const;
44  sys::TimeValue getLastModified() const;
45  llvm::StringRef getRawLastModified() const {
46    return StringRef(LastModified, sizeof(LastModified)).rtrim(' ');
47  }
48  unsigned getUID() const;
49  unsigned getGID() const;
50};
51
52class Archive : public Binary {
53  virtual void anchor();
54public:
55  class Child {
56    friend Archive;
57    const Archive *Parent;
58    /// \brief Includes header but not padding byte.
59    StringRef Data;
60    /// \brief Offset from Data to the start of the file.
61    uint16_t StartOfFile;
62
63    const ArchiveMemberHeader *getHeader() const {
64      return reinterpret_cast<const ArchiveMemberHeader *>(Data.data());
65    }
66
67    bool isThinMember() const;
68
69  public:
70    Child(const Archive *Parent, const char *Start, std::error_code *EC);
71    Child(const Archive *Parent, StringRef Data, uint16_t StartOfFile);
72
73    bool operator ==(const Child &other) const {
74      assert(Parent == other.Parent);
75      return Data.begin() == other.Data.begin();
76    }
77
78    const Archive *getParent() const { return Parent; }
79    ErrorOr<Child> getNext() const;
80
81    ErrorOr<StringRef> getName() const;
82    ErrorOr<std::string> getFullName() const;
83    StringRef getRawName() const { return getHeader()->getName(); }
84    sys::TimeValue getLastModified() const {
85      return getHeader()->getLastModified();
86    }
87    StringRef getRawLastModified() const {
88      return getHeader()->getRawLastModified();
89    }
90    unsigned getUID() const { return getHeader()->getUID(); }
91    unsigned getGID() const { return getHeader()->getGID(); }
92    sys::fs::perms getAccessMode() const {
93      return getHeader()->getAccessMode();
94    }
95    /// \return the size of the archive member without the header or padding.
96    ErrorOr<uint64_t> getSize() const;
97    /// \return the size in the archive header for this member.
98    ErrorOr<uint64_t> getRawSize() const;
99
100    ErrorOr<StringRef> getBuffer() const;
101    uint64_t getChildOffset() const;
102
103    ErrorOr<MemoryBufferRef> getMemoryBufferRef() const;
104
105    Expected<std::unique_ptr<Binary>>
106    getAsBinary(LLVMContext *Context = nullptr) const;
107  };
108
109  class child_iterator {
110    Child C;
111    Error *E;
112
113  public:
114    child_iterator() : C(Child(nullptr, nullptr, nullptr)), E(nullptr) {}
115    child_iterator(const Child &C, Error *E) : C(C), E(E) {}
116    const Child *operator->() const { return &C; }
117    const Child &operator*() const { return C; }
118
119    bool operator==(const child_iterator &other) const {
120      // Ignore errors here: If an error occurred during increment then getNext
121      // will have been set to child_end(), and the following comparison should
122      // do the right thing.
123      return C == other.C;
124    }
125
126    bool operator!=(const child_iterator &other) const {
127      return !(*this == other);
128    }
129
130    // Code in loops with child_iterators must check for errors on each loop
131    // iteration.  And if there is an error break out of the loop.
132    child_iterator &operator++() { // Preincrement
133      assert(E && "Can't increment iterator with no Error attached");
134      if (auto ChildOrErr = C.getNext())
135        C = *ChildOrErr;
136      else {
137        ErrorAsOutParameter ErrAsOutParam(*E);
138        C = C.getParent()->child_end().C;
139        *E = errorCodeToError(ChildOrErr.getError());
140        E = nullptr;
141      }
142      return *this;
143    }
144  };
145
146  class Symbol {
147    const Archive *Parent;
148    uint32_t SymbolIndex;
149    uint32_t StringIndex; // Extra index to the string.
150
151  public:
152    bool operator ==(const Symbol &other) const {
153      return (Parent == other.Parent) && (SymbolIndex == other.SymbolIndex);
154    }
155
156    Symbol(const Archive *p, uint32_t symi, uint32_t stri)
157      : Parent(p)
158      , SymbolIndex(symi)
159      , StringIndex(stri) {}
160    StringRef getName() const;
161    ErrorOr<Child> getMember() const;
162    Symbol getNext() const;
163  };
164
165  class symbol_iterator {
166    Symbol symbol;
167  public:
168    symbol_iterator(const Symbol &s) : symbol(s) {}
169    const Symbol *operator->() const { return &symbol; }
170    const Symbol &operator*() const { return symbol; }
171
172    bool operator==(const symbol_iterator &other) const {
173      return symbol == other.symbol;
174    }
175
176    bool operator!=(const symbol_iterator &other) const {
177      return !(*this == other);
178    }
179
180    symbol_iterator& operator++() {  // Preincrement
181      symbol = symbol.getNext();
182      return *this;
183    }
184  };
185
186  Archive(MemoryBufferRef Source, Error &Err);
187  static Expected<std::unique_ptr<Archive>> create(MemoryBufferRef Source);
188
189  enum Kind {
190    K_GNU,
191    K_MIPS64,
192    K_BSD,
193    K_DARWIN64,
194    K_COFF
195  };
196
197  Kind kind() const { return (Kind)Format; }
198  bool isThin() const { return IsThin; }
199
200  child_iterator child_begin(Error &Err, bool SkipInternal = true) const;
201  child_iterator child_end() const;
202  iterator_range<child_iterator> children(Error &Err,
203                                          bool SkipInternal = true) const {
204    return make_range(child_begin(Err, SkipInternal), child_end());
205  }
206
207  symbol_iterator symbol_begin() const;
208  symbol_iterator symbol_end() const;
209  iterator_range<symbol_iterator> symbols() const {
210    return make_range(symbol_begin(), symbol_end());
211  }
212
213  // Cast methods.
214  static inline bool classof(Binary const *v) {
215    return v->isArchive();
216  }
217
218  // check if a symbol is in the archive
219  Expected<Optional<Child>> findSym(StringRef name) const;
220
221  bool hasSymbolTable() const;
222  StringRef getSymbolTable() const { return SymbolTable; }
223  uint32_t getNumberOfSymbols() const;
224
225  std::vector<std::unique_ptr<MemoryBuffer>> takeThinBuffers() {
226    return std::move(ThinBuffers);
227  }
228
229private:
230  StringRef SymbolTable;
231  StringRef StringTable;
232
233  StringRef FirstRegularData;
234  uint16_t FirstRegularStartOfFile = -1;
235  void setFirstRegular(const Child &C);
236
237  unsigned Format : 3;
238  unsigned IsThin : 1;
239  mutable std::vector<std::unique_ptr<MemoryBuffer>> ThinBuffers;
240};
241
242}
243}
244
245#endif
246