gdb/dwarf-index-common.c

   1 /* Things needed for both reading and writing DWARF indices.
   2
   3    Copyright (C) 1994-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 /* Local non-gdb includes.  */
  23 #include "dwarf-index-common.h"
  24
  25 /* See dwarf-index-common.h.  */
  26
  27 hashval_t
  28 mapped_index_string_hash (int index_version, const void *p)
  29 {
  30   const unsigned char *str = (const unsigned char *) p;
  31   hashval_t r = 0;
  32   unsigned char c;
  33
  34   while ((c = *str++) != 0)
  35     {
  36       if (index_version >= 5)
  37         c = tolower (c);
  38       r = r * 67 + c - 113;
  39     }
  40
  41   return r;
  42 }
  43
  44 /* See dwarf-index-common.h.  */
  45
  46 uint32_t
  47 dwarf5_djb_hash (const char *str_)
  48 {
  49   const unsigned char *str = (const unsigned char *) str_;
  50
  51   /* Note: tolower here ignores UTF-8, which isn't fully compliant.
  52      See http://dwarfstd.org/ShowIssue.php?issue=161027.1.  */
  53
  54   uint32_t hash = 5381;
  55   while (int c = *str++)
  56     hash = hash * 33 + tolower (c);
  57   return hash;
  58 }