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 internal_function
  98 EXTRACT_PLURAL_EXPRESSION (const char *nullentry,
  99                            const struct expression **pluralp,
 100                            unsigned long int *npluralsp)
 101 {
 102   if (nullentry != NULL)
 103     {
 104       const char *plural;
 105       const char *nplurals;
 106
 107       plural = strstr (nullentry, "plural=");
 108       nplurals = strstr (nullentry, "nplurals=");
 109       if (plural == NULL || nplurals == NULL)
 110         goto no_plural;
 111       else
 112         {
 113           char *endp;
 114           unsigned long int n;
 115           struct parse_args args;
 116
 117           /* First get the number.  */
 118           nplurals += 9;
 119           while (*nplurals != '\0' && isspace ((unsigned char) *nplurals))
 120             ++nplurals;
 121           if (!(*nplurals >= '0' && *nplurals <= '9'))
 122             goto no_plural;
 123 #if defined HAVE_STRTOUL || defined _LIBC
 124           n = strtoul (nplurals, &endp, 10);
 125 #else
 126           for (endp = nplurals, n = 0; *endp >= '0' && *endp <= '9'; endp++)
 127             n = n * 10 + (*endp - '0');
 128 #endif
 129           if (nplurals == endp)
 130             goto no_plural;
 131           *npluralsp = n;
 132
 133           /* Due to the restrictions bison imposes onto the interface of the
 134              scanner function we have to put the input string and the result
 135              passed up from the parser into the same structure which address
 136              is passed down to the parser.  */
 137           plural += 7;
 138           args.cp = plural;
 139           if (PLURAL_PARSE (&args) != 0)
 140             goto no_plural;
 141           *pluralp = args.res;
 142         }
 143     }
 144   else
 145     {
 146       /* By default we are using the Germanic form: singular form only
 147          for `one', the plural form otherwise.  Yes, this is also what
 148          English is using since English is a Germanic language.  */
 149     no_plural:
 150       INIT_GERMANIC_PLURAL ();
 151       *pluralp = &GERMANIC_PLURAL;
 152       *npluralsp = 2;
 153     }
 154 }