mingw/share/gettext/intl/plural.y

   1 %{
   2 /* Expression parsing for plural form selection.
   3    Copyright (C) 2000-2001, 2003, 2005-2006 Free Software Foundation, Inc.
   4    Written by Ulrich Drepper <drepper@cygnus.com>, 2000.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU Library General Public License as published
   8    by the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program 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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19    USA.  */
  20
  21 /* For bison < 2.0, the bison generated parser uses alloca.  AIX 3 forces us
  22    to put this declaration at the beginning of the file.  The declaration in
  23    bison's skeleton file comes too late.  This must come before <config.h>
  24    because <config.h> may include arbitrary system headers.
  25    This can go away once the AM_INTL_SUBDIR macro requires bison >= 2.0.  */
  26 #if defined _AIX && !defined __GNUC__
  27  #pragma alloca
  28 #endif
  29
  30 #ifdef HAVE_CONFIG_H
  31 # include <config.h>
  32 #endif
  33
  34 #include <stddef.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include "plural-exp.h"
  38
  39 /* The main function generated by the parser is called __gettextparse,
  40    but we want it to be called PLURAL_PARSE.  */
  41 #ifndef _LIBC
  42 # define __gettextparse PLURAL_PARSE
  43 #endif
  44
  45 #define YYLEX_PARAM     &((struct parse_args *) arg)->cp
  46 #define YYPARSE_PARAM   arg
  47 %}
  48 %pure_parser
  49 %expect 7
  50
  51 %union {
  52   unsigned long int num;
  53   enum expression_operator op;
  54   struct expression *exp;
  55 }
  56
  57 %{
  58 /* Prototypes for local functions.  */
  59 static int yylex (YYSTYPE *lval, const char **pexp);
  60 static void yyerror (const char *str);
  61
  62 /* Allocation of expressions.  */
  63
  64 static struct expression *
  65 new_exp (int nargs, enum expression_operator op,
  66          struct expression * const *args)
  67 {
  68   int i;
  69   struct expression *newp;
  70
  71   /* If any of the argument could not be malloc'ed, just return NULL.  */
  72   for (i = nargs - 1; i >= 0; i--)
  73     if (args[i] == NULL)
  74       goto fail;
  75
  76   /* Allocate a new expression.  */
  77   newp = (struct expression *) malloc (sizeof (*newp));
  78   if (newp != NULL)
  79     {
  80       newp->nargs = nargs;
  81       newp->operation = op;
  82       for (i = nargs - 1; i >= 0; i--)
  83         newp->val.args[i] = args[i];
  84       return newp;
  85     }
  86
  87  fail:
  88   for (i = nargs - 1; i >= 0; i--)
  89     FREE_EXPRESSION (args[i]);
  90
  91   return NULL;
  92 }
  93
  94 static inline struct expression *
  95 new_exp_0 (enum expression_operator op)
  96 {
  97   return new_exp (0, op, NULL);
  98 }
  99
 100 static inline struct expression *
 101 new_exp_1 (enum expression_operator op, struct expression *right)
 102 {
 103   struct expression *args[1];
 104
 105   args[0] = right;
 106   return new_exp (1, op, args);
 107 }
 108
 109 static struct expression *
 110 new_exp_2 (enum expression_operator op, struct expression *left,
 111            struct expression *right)
 112 {
 113   struct expression *args[2];
 114
 115   args[0] = left;
 116   args[1] = right;
 117   return new_exp (2, op, args);
 118 }
 119
 120 static inline struct expression *
 121 new_exp_3 (enum expression_operator op, struct expression *bexp,
 122            struct expression *tbranch, struct expression *fbranch)
 123 {
 124   struct expression *args[3];
 125
 126   args[0] = bexp;
 127   args[1] = tbranch;
 128   args[2] = fbranch;
 129   return new_exp (3, op, args);
 130 }
 131
 132 %}
 133
 134 /* This declares that all operators have the same associativity and the
 135    precedence order as in C.  See [Harbison, Steele: C, A Reference Manual].
 136    There is no unary minus and no bitwise operators.
 137    Operators with the same syntactic behaviour have been merged into a single
 138    token, to save space in the array generated by bison.  */
 139 %right '?'              /*   ?          */
 140 %left '|'               /*   ||         */
 141 %left '&'               /*   &&         */
 142 %left EQUOP2            /*   == !=      */
 143 %left CMPOP2            /*   < > <= >=  */
 144 %left ADDOP2            /*   + -        */
 145 %left MULOP2            /*   * / %      */
 146 %right '!'              /*   !          */
 147
 148 %token <op> EQUOP2 CMPOP2 ADDOP2 MULOP2
 149 %token <num> NUMBER
 150 %type <exp> exp
 151
 152 %%
 153
 154 start:    exp
 155           {
 156             if ($1 == NULL)
 157               YYABORT;
 158             ((struct parse_args *) arg)->res = $1;
 159           }
 160         ;
 161
 162 exp:      exp '?' exp ':' exp
 163           {
 164             $$ = new_exp_3 (qmop, $1, $3, $5);
 165           }
 166         | exp '|' exp
 167           {
 168             $$ = new_exp_2 (lor, $1, $3);
 169           }
 170         | exp '&' exp
 171           {
 172             $$ = new_exp_2 (land, $1, $3);
 173           }
 174         | exp EQUOP2 exp
 175           {
 176             $$ = new_exp_2 ($2, $1, $3);
 177           }
 178         | exp CMPOP2 exp
 179           {
 180             $$ = new_exp_2 ($2, $1, $3);
 181           }
 182         | exp ADDOP2 exp
 183           {
 184             $$ = new_exp_2 ($2, $1, $3);
 185           }
 186         | exp MULOP2 exp
 187           {
 188             $$ = new_exp_2 ($2, $1, $3);
 189           }
 190         | '!' exp
 191           {
 192             $$ = new_exp_1 (lnot, $2);
 193           }
 194         | 'n'
 195           {
 196             $$ = new_exp_0 (var);
 197           }
 198         | NUMBER
 199           {
 200             if (($$ = new_exp_0 (num)) != NULL)
 201               $$->val.num = $1;
 202           }
 203         | '(' exp ')'
 204           {
 205             $$ = $2;
 206           }
 207         ;
 208
 209 %%
 210
 211 void
 212 internal_function
 213 FREE_EXPRESSION (struct expression *exp)
 214 {
 215   if (exp == NULL)
 216     return;
 217
 218   /* Handle the recursive case.  */
 219   switch (exp->nargs)
 220     {
 221     case 3:
 222       FREE_EXPRESSION (exp->val.args[2]);
 223       /* FALLTHROUGH */
 224     case 2:
 225       FREE_EXPRESSION (exp->val.args[1]);
 226       /* FALLTHROUGH */
 227     case 1:
 228       FREE_EXPRESSION (exp->val.args[0]);
 229       /* FALLTHROUGH */
 230     default:
 231       break;
 232     }
 233
 234   free (exp);
 235 }
 236
 237
 238 static int
 239 yylex (YYSTYPE *lval, const char **pexp)
 240 {
 241   const char *exp = *pexp;
 242   int result;
 243
 244   while (1)
 245     {
 246       if (exp[0] == '\0')
 247         {
 248           *pexp = exp;
 249           return YYEOF;
 250         }
 251
 252       if (exp[0] != ' ' && exp[0] != '\t')
 253         break;
 254
 255       ++exp;
 256     }
 257
 258   result = *exp++;
 259   switch (result)
 260     {
 261     case '0': case '1': case '2': case '3': case '4':
 262     case '5': case '6': case '7': case '8': case '9':
 263       {
 264         unsigned long int n = result - '0';
 265         while (exp[0] >= '0' && exp[0] <= '9')
 266           {
 267             n *= 10;
 268             n += exp[0] - '0';
 269             ++exp;
 270           }
 271         lval->num = n;
 272         result = NUMBER;
 273       }
 274       break;
 275
 276     case '=':
 277       if (exp[0] == '=')
 278         {
 279           ++exp;
 280           lval->op = equal;
 281           result = EQUOP2;
 282         }
 283       else
 284         result = YYERRCODE;
 285       break;
 286
 287     case '!':
 288       if (exp[0] == '=')
 289         {
 290           ++exp;
 291           lval->op = not_equal;
 292           result = EQUOP2;
 293         }
 294       break;
 295
 296     case '&':
 297     case '|':
 298       if (exp[0] == result)
 299         ++exp;
 300       else
 301         result = YYERRCODE;
 302       break;
 303
 304     case '<':
 305       if (exp[0] == '=')
 306         {
 307           ++exp;
 308           lval->op = less_or_equal;
 309         }
 310       else
 311         lval->op = less_than;
 312       result = CMPOP2;
 313       break;
 314
 315     case '>':
 316       if (exp[0] == '=')
 317         {
 318           ++exp;
 319           lval->op = greater_or_equal;
 320         }
 321       else
 322         lval->op = greater_than;
 323       result = CMPOP2;
 324       break;
 325
 326     case '*':
 327       lval->op = mult;
 328       result = MULOP2;
 329       break;
 330
 331     case '/':
 332       lval->op = divide;
 333       result = MULOP2;
 334       break;
 335
 336     case '%':
 337       lval->op = module;
 338       result = MULOP2;
 339       break;
 340
 341     case '+':
 342       lval->op = plus;
 343       result = ADDOP2;
 344       break;
 345
 346     case '-':
 347       lval->op = minus;
 348       result = ADDOP2;
 349       break;
 350
 351     case 'n':
 352     case '?':
 353     case ':':
 354     case '(':
 355     case ')':
 356       /* Nothing, just return the character.  */
 357       break;
 358
 359     case ';':
 360     case '\n':
 361     case '\0':
 362       /* Be safe and let the user call this function again.  */
 363       --exp;
 364       result = YYEOF;
 365       break;
 366
 367     default:
 368       result = YYERRCODE;
 369 #if YYDEBUG != 0
 370       --exp;
 371 #endif
 372       break;
 373     }
 374
 375   *pexp = exp;
 376
 377   return result;
 378 }
 379
 380
 381 static void
 382 yyerror (const char *str)
 383 {
 384   /* Do nothing.  We don't print error messages here.  */
 385 }