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 
26 namespace llvm {
27 namespace object {
28 struct 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;
getRawLastModifiedArchiveMemberHeader45   llvm::StringRef getRawLastModified() const {
46     return StringRef(LastModified, sizeof(LastModified)).rtrim(' ');
47   }
48   unsigned getUID() const;
49   unsigned getGID() const;
50 };
51 
52 class Archive : public Binary {
53   virtual void anchor();
54 public:
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 
getHeader()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 
getParent()78     const Archive *getParent() const { return Parent; }
79     ErrorOr<Child> getNext() const;
80 
81     ErrorOr<StringRef> getName() const;
82     ErrorOr<std::string> getFullName() const;
getRawName()83     StringRef getRawName() const { return getHeader()->getName(); }
getLastModified()84     sys::TimeValue getLastModified() const {
85       return getHeader()->getLastModified();
86     }
getRawLastModified()87     StringRef getRawLastModified() const {
88       return getHeader()->getRawLastModified();
89     }
getUID()90     unsigned getUID() const { return getHeader()->getUID(); }
getGID()91     unsigned getGID() const { return getHeader()->getGID(); }
getAccessMode()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:
child_iterator()114     child_iterator() : C(Child(nullptr, nullptr, nullptr)), E(nullptr) {}
child_iterator(const Child & C,Error * E)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 
Symbol(const Archive * p,uint32_t symi,uint32_t stri)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:
symbol_iterator(const Symbol & s)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 
kind()197   Kind kind() const { return (Kind)Format; }
isThin()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;
symbols()209   iterator_range<symbol_iterator> symbols() const {
210     return make_range(symbol_begin(), symbol_end());
211   }
212 
213   // Cast methods.
classof(Binary const * v)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;
getSymbolTable()222   StringRef getSymbolTable() const { return SymbolTable; }
223   uint32_t getNumberOfSymbols() const;
224 
takeThinBuffers()225   std::vector<std::unique_ptr<MemoryBuffer>> takeThinBuffers() {
226     return std::move(ThinBuffers);
227   }
228 
229 private:
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