intl/plural-exp.c

   1 /* Expression parsing for plural form selection.
   2    Copyright (C) 2000, 2001, 2005, 2007 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include <ctype.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "plural-exp.h"
  29
  30 #if (defined __GNUC__ && !defined __APPLE_CC__) \
  31     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
  32
  33 /* These structs are the constant expression for the germanic plural
  34    form determination.  It represents the expression  "n != 1".  */
  35 static const struct expression plvar =
  36 {
  37   .nargs = 0,
  38   .operation = var,
  39 };
  40 static const struct expression plone =
  41 {
  42   .nargs = 0,
  43   .operation = num,
  44   .val =
  45   {
  46     .num = 1
  47   }
  48 };
  49 const struct expression GERMANIC_PLURAL =
  50 {
  51   .nargs = 2,
  52   .operation = not_equal,
  53   .val =
  54   {
  55     .args =
  56     {
  57       [0] = (struct expression *) &plvar,
  58       [1] = (struct expression *) &plone
  59     }
  60   }
  61 };
  62
  63 # define INIT_GERMANIC_PLURAL()
  64
  65 #else
  66
  67 /* For compilers without support for ISO C 99 struct/union initializers:
  68    Initialization at run-time.  */
  69
  70 static struct expression plvar;
  71 static struct expression plone;
  72 struct expression GERMANIC_PLURAL;
  73
  74 static void
  75 init_germanic_plural ()
  76 {
  77   if (plone.val.num == 0)
  78     {
  79       plvar.nargs = 0;
  80       plvar.operation = var;
  81
  82       plone.nargs = 0;
  83       plone.operation = num;
  84       plone.val.num = 1;
  85
  86       GERMANIC_PLURAL.nargs = 2;
  87       GERMANIC_PLURAL.operation = not_equal;
  88       GERMANIC_PLURAL.val.args[0] = &plvar;
  89       GERMANIC_PLURAL.val.args[1] = &plone;
  90     }
  91 }
  92
  93 # define INIT_GERMANIC_PLURAL() init_germanic_plural ()
  94
  95 #endif
  96
  97 void
  98 internal_function
  99 EXTRACT_PLURAL_EXPRESSION (nullentry, pluralp, npluralsp)
 100      const char *nullentry;
 101      const struct expression **pluralp;
 102      unsigned long int *npluralsp;
 103 {
 104   if (nullentry != NULL)
 105     {
 106       const char *plural;
 107       const char *nplurals;
 108
 109       plural = strstr (nullentry, "plural=");
 110       nplurals = strstr (nullentry, "nplurals=");
 111       if (plural == NULL || nplurals == NULL)
 112         goto no_plural;
 113       else
 114         {
 115           char *endp;
 116           unsigned long int n;
 117           struct parse_args args;
 118
 119           /* First get the number.  */
 120           nplurals += 9;
 121           while (*nplurals != '\0' && isspace ((unsigned char) *nplurals))
 122             ++nplurals;
 123           if (!(*nplurals >= '0' && *nplurals <= '9'))
 124             goto no_plural;
 125 #if defined HAVE_STRTOUL || defined _LIBC
 126           n = strtoul (nplurals, &endp, 10);
 127 #else
 128           for (endp = nplurals, n = 0; *endp >= '0' && *endp <= '9'; endp++)
 129             n = n * 10 + (*endp - '0');
 130 #endif
 131           if (nplurals == endp)
 132             goto no_plural;
 133           *npluralsp = n;
 134
 135           /* Due to the restrictions bison imposes onto the interface of the
 136              scanner function we have to put the input string and the result
 137              passed up from the parser into the same structure which address
 138              is passed down to the parser.  */
 139           plural += 7;
 140           args.cp = plural;
 141           if (PLURAL_PARSE (&args) != 0)
 142             goto no_plural;
 143           *pluralp = args.res;
 144         }
 145     }
 146   else
 147     {
 148       /* By default we are using the Germanic form: singular form only
 149          for `one', the plural form otherwise.  Yes, this is also what
 150          English is using since English is a Germanic language.  */
 151     no_plural:
 152       INIT_GERMANIC_PLURAL ();
 153       *pluralp = &GERMANIC_PLURAL;
 154       *npluralsp = 2;
 155     }
 156 }