merge from gcc
[binutils.git] / gold / stringpool.h
blob05c498e49fac165faab2cf566cb5c0af67b7877f
1 // stringpool.h -- a string pool for gold -*- C++ -*-
3 #include <string>
4 #include <list>
6 // Stringpool
7 // Manage a pool of unique strings.
9 #ifndef GOLD_STRINGPOOL_H
10 #define GOLD_STRINGPOOL_H
12 namespace gold
15 class Output_file;
17 class Stringpool
19 public:
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.
25 typedef size_t Key;
27 Stringpool();
29 ~Stringpool();
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.
34 const char*
35 add(const char*, Key* pkey);
37 const char*
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.
42 const char*
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.
47 const char*
48 find(const char*, Key* pkey) const;
50 // Turn the stringpool into an ELF strtab: determine the offsets of
51 // all the strings.
52 void
53 set_string_offsets();
55 // Get the offset of a string in an ELF strtab.
56 off_t
57 get_offset(const char*) const;
59 off_t
60 get_offset(const std::string& s) const
61 { return this->get_offset(s.c_str()); }
63 // Get the size of the ELF strtab.
64 off_t
65 get_strtab_size() const
67 gold_assert(this->strtab_size_ != 0);
68 return this->strtab_size_;
71 // Write the strtab into the output file at the specified offset.
72 void
73 write(Output_file*, off_t offset);
75 private:
76 Stringpool(const Stringpool&);
77 Stringpool& operator=(const Stringpool&);
79 // We store the actual data in a list of these buffers.
80 struct Stringdata
82 // Length of data in buffer.
83 size_t len;
84 // Allocated size of buffer.
85 size_t alc;
86 // Buffer index.
87 unsigned int index;
88 // Buffer.
89 char data[1];
92 // Copy a string into the buffers, returning a canonical string.
93 const char*
94 add_string(const char*, Key*);
96 struct Stringpool_hash
98 size_t
99 operator()(const char*) const;
102 struct Stringpool_eq
104 bool
105 operator()(const char* p1, const char* p2) const
106 { return strcmp(p1, p2) == 0; }
109 // Return whether s1 is a suffix of s2.
110 static bool is_suffix(const char* s1, const char* s2);
112 // The hash table is a map from string names to a pair of Key and
113 // ELF strtab offsets. We only use the offsets if we turn this into
114 // an ELF strtab section.
116 typedef std::pair<Key, off_t> Val;
118 #ifdef HAVE_TR1_UNORDERED_SET
119 typedef Unordered_map<const char*, Val, Stringpool_hash,
120 Stringpool_eq,
121 std::allocator<std::pair<const char* const, Val> >,
122 true> String_set_type;
123 #else
124 typedef Unordered_map<const char*, Val, Stringpool_hash,
125 Stringpool_eq> String_set_type;
126 #endif
128 // Comparison routine used when sorting into an ELF strtab.
130 struct Stringpool_sort_comparison
132 bool
133 operator()(String_set_type::iterator,
134 String_set_type::iterator) const;
137 // List of Stringdata structures.
138 typedef std::list<Stringdata*> Stringdata_list;
140 // Mapping from const char* to namepool entry.
141 String_set_type string_set_;
142 // List of buffers.
143 Stringdata_list strings_;
144 // Size of ELF strtab.
145 off_t strtab_size_;
146 // Next Stringdata index.
147 unsigned int next_index_;
150 } // End namespace gold.
152 #endif // !defined(GOLD_STRINGPOOL_H)