intl/plural-exp.c

   1 /* Expression parsing for plural form selection.
   2    Copyright (C) 2000-2017 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as published by
   7    the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include <ctype.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <plural-exp.h>
  27
  28 #if (defined __GNUC__ && !(defined __APPLE_CC_ && __APPLE_CC__ > 1) && \
  29      !defined __cplusplus)                                             \
  30     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
  31
  32 /* These structs are the constant expression for the germanic plural
  33    form determination.  It represents the expression  "n != 1".  */
  34 static const struct expression plvar =
  35 {
  36   .nargs = 0,
  37   .operation = var,
  38 };
  39 static const struct expression plone =
  40 {
  41   .nargs = 0,
  42   .operation = num,
  43   .val =
  44   {
  45     .num = 1
  46   }
  47 };
  48 const struct expression GERMANIC_PLURAL =
  49 {
  50   .nargs = 2,
  51   .operation = not_equal,
  52   .val =
  53   {
  54     .args =
  55     {
  56       [0] = (struct expression *) &plvar,
  57       [1] = (struct expression *) &plone
  58     }
  59   }
  60 };
  61
  62 # define INIT_GERMANIC_PLURAL()
  63
  64 #else
  65
  66 /* For compilers without support for ISO C 99 struct/union initializers:
  67    Initialization at run-time.  */
  68
  69 static struct expression plvar;
  70 static struct expression plone;
  71 struct expression GERMANIC_PLURAL;
  72
  73 static void
  74 init_germanic_plural (void)
  75 {
  76   if (plone.val.num == 0)
  77     {
  78       plvar.nargs = 0;
  79       plvar.operation = var;
  80
  81       plone.nargs = 0;
  82       plone.operation = num;
  83       plone.val.num = 1;
  84
  85       GERMANIC_PLURAL.nargs = 2;
  86       GERMANIC_PLURAL.operation = not_equal;
  87       GERMANIC_PLURAL.val.args[0] = &plvar;
  88       GERMANIC_PLURAL.val.args[1] = &plone;
  89     }
  90 }
  91
  92 # define INIT_GERMANIC_PLURAL() init_germanic_plural ()
  93
  94 #endif
  95
  96 void
  97 EXTRACT_PLURAL_EXPRESSION (const char *nullentry,
  98                            const struct expression **pluralp,
  99                            unsigned long int *npluralsp)
 100 {
 101   if (nullentry != NULL)
 102     {
 103       const char *plural;
 104       const char *nplurals;
 105
 106       plural = strstr (nullentry, "plural=");
 107       nplurals = strstr (nullentry, "nplurals=");
 108       if (plural == NULL || nplurals == NULL)
 109         goto no_plural;
 110       else
 111         {
 112           char *endp;
 113           unsigned long int n;
 114           struct parse_args args;
 115
 116           /* First get the number.  */
 117           nplurals += 9;
 118           while (*nplurals != '\0' && isspace ((unsigned char) *nplurals))
 119             ++nplurals;
 120           if (!(*nplurals >= '0' && *nplurals <= '9'))
 121             goto no_plural;
 122 #if defined HAVE_STRTOUL || defined _LIBC
 123           n = strtoul (nplurals, &endp, 10);
 124 #else
 125           for (endp = nplurals, n = 0; *endp >= '0' && *endp <= '9'; endp++)
 126             n = n * 10 + (*endp - '0');
 127 #endif
 128           if (nplurals == endp)
 129             goto no_plural;
 130           *npluralsp = n;
 131
 132           /* Due to the restrictions bison imposes onto the interface of the
 133              scanner function we have to put the input string and the result
 134              passed up from the parser into the same structure which address
 135              is passed down to the parser.  */
 136           plural += 7;
 137           args.cp = plural;
 138           if (PLURAL_PARSE (&args) != 0)
 139             goto no_plural;
 140           *pluralp = args.res;
 141         }
 142     }
 143   else
 144     {
 145       /* By default we are using the Germanic form: singular form only
 146          for `one', the plural form otherwise.  Yes, this is also what
 147          English is using since English is a Germanic language.  */
 148     no_plural:
 149       INIT_GERMANIC_PLURAL ();
 150       *pluralp = &GERMANIC_PLURAL;
 151       *npluralsp = 2;
 152     }
 153 }