elf/stringtable.h

   1 /* String tables for ld.so.cache construction.
   2    Copyright (C) 2020-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published
   7    by the Free Software Foundation; version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _STRINGTABLE_H
  19 #define _STRINGTABLE_H
  20
  21 #include <stddef.h>
  22 #include <stdint.h>
  23
  24 /* An entry in the string table.  Only the length and string fields are
  25    expected to be used outside the string table code.  */
  26 struct stringtable_entry
  27 {
  28   struct stringtable_entry *next; /* For collision resolution.  */
  29   uint32_t length;                /* Length of then string.  */
  30   uint32_t offset;                /* From start of finalized table.  */
  31   char string[];                  /* Null-terminated string.  */
  32 };
  33
  34 /* A string table.  Zero-initialization produces a valid atable.  */
  35 struct stringtable
  36 {
  37   struct stringtable_entry **entries;  /* Array of hash table buckets.  */
  38   uint32_t count;                 /* Number of elements in the table.  */
  39   uint32_t allocated;             /* Length of the entries array.  */
  40 };
  41
  42 /* Adds STRING to TABLE.  May return the address of an existing entry.  */
  43 struct stringtable_entry *stringtable_add (struct stringtable *table,
  44                                            const char *string);
  45
  46 /* Result of stringtable_finalize.  SIZE bytes at STRINGS should be
  47    written to the file.  */
  48 struct stringtable_finalized
  49 {
  50   char *strings;
  51   size_t size;
  52 };
  53
  54 /* Assigns offsets to string table entries and computes the serialized
  55    form of the string table.  */
  56 void stringtable_finalize (struct stringtable *table,
  57                            struct stringtable_finalized *result);
  58
  59 /* Deallocate the string table (but not the TABLE pointer itself).
  60    (The table can be re-used for adding more strings without
  61    initialization.)  */
  62 void stringtable_free (struct stringtable *table);
  63
  64 #endif /* _STRINGTABLE_H */