gold/stringpool.h

   1 // stringpool.h -- a string pool for gold    -*- C++ -*-
   2
   3 #include <string>
   4 #include <list>
   5
   6 // Stringpool
   7 //   Manage a pool of unique strings.
   8
   9 #ifndef GOLD_STRINGPOOL_H
  10 #define GOLD_STRINGPOOL_H
  11
  12 namespace gold
  13 {
  14
  15 class Output_file;
  16
  17 class Stringpool
  18 {
  19  public:
  20   Stringpool();
  21
  22   ~Stringpool();
  23
  24   // Add a string to the pool.  This returns a canonical permanent
  25   // pointer to the string.
  26   const char*
  27   add(const char*);
  28
  29   const char*
  30   add(const std::string& s)
  31   { return this->add(s.c_str()); }
  32
  33   // Add the prefix of a string to the pool.
  34   const char*
  35   add(const char *, size_t);
  36
  37   // If a string is present, return the canonical string.  Otherwise,
  38   // return NULL.
  39   const char*
  40   find(const char*) const;
  41
  42   // Turn the stringpool into an ELF strtab: determine the offsets of
  43   // all the strings.
  44   void
  45   set_string_offsets();
  46
  47   // Get the offset of a string.
  48   off_t
  49   get_offset(const char*) const;
  50
  51   off_t
  52   get_offset(const std::string& s) const
  53   { return this->get_offset(s.c_str()); }
  54
  55   // Get the size of the ELF strtab.
  56   off_t
  57   get_strtab_size() const
  58   { return this->strtab_size_; }
  59
  60   // Write the strtab into the output file at the specified offset.
  61   void
  62   write(Output_file*, off_t offset);
  63
  64  private:
  65   Stringpool(const Stringpool&);
  66   Stringpool& operator=(const Stringpool&);
  67
  68   // We store the actual data in a list of these buffers.
  69   struct Stringdata
  70   {
  71     // Length of data in buffer.
  72     size_t len;
  73     // Allocated size of buffer.
  74     size_t alc;
  75     // Buffer.
  76     char data[1];
  77   };
  78
  79   // Copy a string into the buffers, returning a canonical string.
  80   const char*
  81   add_string(const char*);
  82
  83   struct Stringpool_hash
  84   {
  85     size_t
  86     operator()(const char*) const;
  87   };
  88
  89   struct Stringpool_eq
  90   {
  91     bool
  92     operator()(const char* p1, const char* p2) const
  93     { return strcmp(p1, p2) == 0; }
  94   };
  95
  96   // Return whether s1 is a suffix of s2.
  97   static bool is_suffix(const char* s1, const char* s2);
  98
  99   // The hash table is a map from string names to offsets.  We only
 100   // use the offsets if we turn this into an ELF strtab section.
 101
 102 #ifdef HAVE_TR1_UNORDERED_SET
 103   typedef Unordered_map<const char*, off_t, Stringpool_hash,
 104                         Stringpool_eq,
 105                         std::allocator<std::pair<const char* const, off_t> >,
 106                         true> String_set_type;
 107 #else
 108   typedef Unordered_map<const char*, off_t, Stringpool_hash,
 109                         Stringpool_eq> String_set_type;
 110 #endif
 111
 112   // Comparison routine used when sorting into an ELF strtab.
 113
 114   struct Stringpool_sort_comparison
 115   {
 116     bool
 117     operator()(String_set_type::iterator,
 118                String_set_type::iterator) const;
 119   };
 120
 121   String_set_type string_set_;
 122   std::list<Stringdata*> strings_;
 123   off_t strtab_size_;
 124 };
 125
 126 } // End namespace gold.
 127
 128 #endif // !defined(GOLD_STRINGPOOL_H)