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/StringRef.h"
18 #include "llvm/ADT/iterator_range.h"
19 #include "llvm/Object/Binary.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/ErrorOr.h"
22 #include "llvm/Support/FileSystem.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 
25 namespace llvm {
26 namespace object {
27 struct ArchiveMemberHeader {
28   char Name[16];
29   char LastModified[12];
30   char UID[6];
31   char GID[6];
32   char AccessMode[8];
33   char Size[10]; ///< Size of data, not including header or padding.
34   char Terminator[2];
35 
36   /// Get the name without looking up long names.
37   llvm::StringRef getName() const;
38 
39   /// Members are not larger than 4GB.
40   uint32_t getSize() const;
41 
42   sys::fs::perms getAccessMode() const;
43   sys::TimeValue getLastModified() const;
getRawLastModifiedArchiveMemberHeader44   llvm::StringRef getRawLastModified() const {
45     return StringRef(LastModified, sizeof(LastModified)).rtrim(" ");
46   }
47   unsigned getUID() const;
48   unsigned getGID() const;
49 };
50 
51 class Archive : public Binary {
52   virtual void anchor();
53 public:
54   class Child {
55     const Archive *Parent;
56     /// \brief Includes header but not padding byte.
57     StringRef Data;
58     /// \brief Offset from Data to the start of the file.
59     uint16_t StartOfFile;
60 
getHeader()61     const ArchiveMemberHeader *getHeader() const {
62       return reinterpret_cast<const ArchiveMemberHeader *>(Data.data());
63     }
64 
65   public:
66     Child(const Archive *Parent, const char *Start);
67 
68     bool operator ==(const Child &other) const {
69       assert(Parent == other.Parent);
70       return Data.begin() == other.Data.begin();
71     }
72 
73     bool operator <(const Child &other) const {
74       return Data.begin() < other.Data.begin();
75     }
76 
77     Child getNext() const;
78 
79     ErrorOr<StringRef> getName() const;
getRawName()80     StringRef getRawName() const { return getHeader()->getName(); }
getLastModified()81     sys::TimeValue getLastModified() const {
82       return getHeader()->getLastModified();
83     }
getRawLastModified()84     StringRef getRawLastModified() const {
85       return getHeader()->getRawLastModified();
86     }
getUID()87     unsigned getUID() const { return getHeader()->getUID(); }
getGID()88     unsigned getGID() const { return getHeader()->getGID(); }
getAccessMode()89     sys::fs::perms getAccessMode() const {
90       return getHeader()->getAccessMode();
91     }
92     /// \return the size of the archive member without the header or padding.
93     uint64_t getSize() const;
94     /// \return the size in the archive header for this member.
95     uint64_t getRawSize() const;
96 
getBuffer()97     StringRef getBuffer() const {
98       return StringRef(Data.data() + StartOfFile, getSize());
99     }
100     uint64_t getChildOffset() const;
101 
102     ErrorOr<MemoryBufferRef> getMemoryBufferRef() const;
103 
104     ErrorOr<std::unique_ptr<Binary>>
105     getAsBinary(LLVMContext *Context = nullptr) const;
106   };
107 
108   class child_iterator {
109     Child child;
110 
111   public:
child_iterator()112     child_iterator() : child(Child(nullptr, nullptr)) {}
child_iterator(const Child & c)113     child_iterator(const Child &c) : child(c) {}
114     const Child *operator->() const { return &child; }
115     const Child &operator*() const { return child; }
116 
117     bool operator==(const child_iterator &other) const {
118       return child == other.child;
119     }
120 
121     bool operator!=(const child_iterator &other) const {
122       return !(*this == other);
123     }
124 
125     bool operator<(const child_iterator &other) const {
126       return child < other.child;
127     }
128 
129     child_iterator &operator++() { // Preincrement
130       child = child.getNext();
131       return *this;
132     }
133   };
134 
135   class Symbol {
136     const Archive *Parent;
137     uint32_t SymbolIndex;
138     uint32_t StringIndex; // Extra index to the string.
139 
140   public:
141     bool operator ==(const Symbol &other) const {
142       return (Parent == other.Parent) && (SymbolIndex == other.SymbolIndex);
143     }
144 
Symbol(const Archive * p,uint32_t symi,uint32_t stri)145     Symbol(const Archive *p, uint32_t symi, uint32_t stri)
146       : Parent(p)
147       , SymbolIndex(symi)
148       , StringIndex(stri) {}
149     StringRef getName() const;
150     ErrorOr<child_iterator> getMember() const;
151     Symbol getNext() const;
152   };
153 
154   class symbol_iterator {
155     Symbol symbol;
156   public:
symbol_iterator(const Symbol & s)157     symbol_iterator(const Symbol &s) : symbol(s) {}
158     const Symbol *operator->() const { return &symbol; }
159     const Symbol &operator*() const { return symbol; }
160 
161     bool operator==(const symbol_iterator &other) const {
162       return symbol == other.symbol;
163     }
164 
165     bool operator!=(const symbol_iterator &other) const {
166       return !(*this == other);
167     }
168 
169     symbol_iterator& operator++() {  // Preincrement
170       symbol = symbol.getNext();
171       return *this;
172     }
173   };
174 
175   Archive(MemoryBufferRef Source, std::error_code &EC);
176   static ErrorOr<std::unique_ptr<Archive>> create(MemoryBufferRef Source);
177 
178   enum Kind {
179     K_GNU,
180     K_MIPS64,
181     K_BSD,
182     K_COFF
183   };
184 
kind()185   Kind kind() const { return (Kind)Format; }
186 
187   child_iterator child_begin(bool SkipInternal = true) const;
188   child_iterator child_end() const;
189   iterator_range<child_iterator> children(bool SkipInternal = true) const {
190     return iterator_range<child_iterator>(child_begin(SkipInternal),
191                                           child_end());
192   }
193 
194   symbol_iterator symbol_begin() const;
195   symbol_iterator symbol_end() const;
symbols()196   iterator_range<symbol_iterator> symbols() const {
197     return iterator_range<symbol_iterator>(symbol_begin(), symbol_end());
198   }
199 
200   // Cast methods.
classof(Binary const * v)201   static inline bool classof(Binary const *v) {
202     return v->isArchive();
203   }
204 
205   // check if a symbol is in the archive
206   child_iterator findSym(StringRef name) const;
207 
208   bool hasSymbolTable() const;
getSymbolTableChild()209   child_iterator getSymbolTableChild() const { return SymbolTable; }
210 
211 private:
212   child_iterator SymbolTable;
213   child_iterator StringTable;
214   child_iterator FirstRegular;
215   unsigned Format : 2;
216   unsigned IsThin : 1;
217 };
218 
219 }
220 }
221 
222 #endif
223