1 // stringpool.h -- a string pool for gold -*- C++ -*-
7 // Manage a pool of unique strings.
9 #ifndef GOLD_STRINGPOOL_H
10 #define GOLD_STRINGPOOL_H
20 // The type of a key into the stringpool. A key value will always
21 // be the same during any run of the linker. The string pointers
22 // may change when using address space randomization. We use key
23 // values in order to get repeatable runs when the value is inserted
24 // into an unordered hash table. Zero is never a valid key.
31 // Add a string to the pool. This returns a canonical permanent
32 // pointer to the string. If PKEY is not NULL, this sets *PKEY to
33 // the key for the string.
35 add(const char*, Key* pkey);
38 add(const std::string& s, Key* pkey)
39 { return this->add(s.c_str(), pkey); }
41 // Add the prefix of a string to the pool.
43 add(const char *, size_t, Key* pkey);
45 // If a string is present, return the canonical string. Otherwise,
46 // return NULL. If PKEY is not NULL, set *PKEY to the key.
48 find(const char*, Key* pkey) const;
50 // Turn the stringpool into an ELF strtab: determine the offsets of
55 // Get the offset of a string in an ELF strtab.
57 get_offset(const char*) const;
60 get_offset(const std::string& s) const
61 { return this->get_offset(s.c_str()); }
63 // Get the size of the ELF strtab.
65 get_strtab_size() const
66 { return this->strtab_size_; }
68 // Write the strtab into the output file at the specified offset.
70 write(Output_file*, off_t offset);
73 Stringpool(const Stringpool&);
74 Stringpool& operator=(const Stringpool&);
76 // We store the actual data in a list of these buffers.
79 // Length of data in buffer.
81 // Allocated size of buffer.
89 // Copy a string into the buffers, returning a canonical string.
91 add_string(const char*, Key*);
93 struct Stringpool_hash
96 operator()(const char*) const;
102 operator()(const char* p1, const char* p2) const
103 { return strcmp(p1, p2) == 0; }
106 // Return whether s1 is a suffix of s2.
107 static bool is_suffix(const char* s1, const char* s2);
109 // The hash table is a map from string names to a pair of Key and
110 // ELF strtab offsets. We only use the offsets if we turn this into
111 // an ELF strtab section.
113 typedef std::pair<Key, off_t> Val;
115 #ifdef HAVE_TR1_UNORDERED_SET
116 typedef Unordered_map<const char*, Val, Stringpool_hash,
118 std::allocator<std::pair<const char* const, Val> >,
119 true> String_set_type;
121 typedef Unordered_map<const char*, Val, Stringpool_hash,
122 Stringpool_eq> String_set_type;
125 // Comparison routine used when sorting into an ELF strtab.
127 struct Stringpool_sort_comparison
130 operator()(String_set_type::iterator,
131 String_set_type::iterator) const;
134 // List of Stringdata structures.
135 typedef std::list<Stringdata*> Stringdata_list;
137 // Mapping from const char* to namepool entry.
138 String_set_type string_set_;
140 Stringdata_list strings_;
141 // Size of ELF strtab.
143 // Next Stringdata index.
144 unsigned int next_index_;
147 } // End namespace gold.
149 #endif // !defined(GOLD_STRINGPOOL_H)