1 %{
2 /* Expression parsing for plural form selection.
3 Copyright (C) 2000, 2001 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 USA. */
20
21 /* The bison generated parser uses alloca. AIX 3 forces us to put this
22 declaration at the beginning of the file. The declaration in bison's
23 skeleton file comes too late. This must come before <autoconf.h>
24 because <autoconf.h> may include arbitrary system headers. */
25 #if defined _AIX && !defined __GNUC__
26 #pragma alloca
27 #endif
28
29 #ifdef HAVE_CONFIG_H
30 # include <autoconf.h>
31 #endif
32
33 #include <stdlib.h>
34 #include "gettextP.h"
35
36 /* Names for the libintl functions are a problem. They must not clash
37 with existing names and they should follow ANSI C. But this source
38 code is also used in GNU C Library where the names have a __
39 prefix. So we have to make a difference here. */
40 #ifdef _LIBC
41 # define FREE_EXPRESSION __gettext_free_exp
42 #else
43 # define FREE_EXPRESSION gettext_free_exp__
44 # define __gettextparse gettextparse__
45 #endif
46
47 #define YYLEX_PARAM &((struct parse_args *) arg)->cp
48 #define YYPARSE_PARAM arg
49 %}
50 %pure_parser
51 %expect 7
52
53 %union {
54 unsigned long int num;
55 enum operator op;
56 struct expression *exp;
57 }
58
59 %{
60 /* Prototypes for local functions. */
61 static struct expression *new_exp PARAMS ((int nargs, enum operator op,
62 struct expression * const *args));
63 static inline struct expression *new_exp_0 PARAMS ((enum operator op));
64 static inline struct expression *new_exp_1 PARAMS ((enum operator op,
65 struct expression *right));
66 static struct expression *new_exp_2 PARAMS ((enum operator op,
67 struct expression *left,
68 struct expression *right));
69 static inline struct expression *new_exp_3 PARAMS ((enum operator op,
70 struct expression *bexp,
71 struct expression *tbranch,
72 struct expression *fbranch));
73 static int yylex PARAMS ((YYSTYPE *lval, const char **pexp));
74 static void yyerror PARAMS ((const char *str));
75
76 /* Allocation of expressions. */
77
78 static struct expression *
new_exp(nargs,op,args)79 new_exp (nargs, op, args)
80 int nargs;
81 enum operator op;
82 struct expression * const *args;
83 {
84 int i;
85 struct expression *newp;
86
87 /* If any of the argument could not be malloc'ed, just return NULL. */
88 for (i = nargs - 1; i >= 0; i--)
89 if (args[i] == NULL)
90 goto fail;
91
92 /* Allocate a new expression. */
93 newp = (struct expression *) malloc (sizeof (*newp));
94 if (newp != NULL)
95 {
96 newp->nargs = nargs;
97 newp->operation = op;
98 for (i = nargs - 1; i >= 0; i--)
99 newp->val.args[i] = args[i];
100 return newp;
101 }
102
103 fail:
104 for (i = nargs - 1; i >= 0; i--)
105 FREE_EXPRESSION (args[i]);
106
107 return NULL;
108 }
109
110 static inline struct expression *
new_exp_0(op)111 new_exp_0 (op)
112 enum operator op;
113 {
114 return new_exp (0, op, NULL);
115 }
116
117 static inline struct expression *
new_exp_1(op,right)118 new_exp_1 (op, right)
119 enum operator op;
120 struct expression *right;
121 {
122 struct expression *args[1];
123
124 args[0] = right;
125 return new_exp (1, op, args);
126 }
127
128 static struct expression *
new_exp_2(op,left,right)129 new_exp_2 (op, left, right)
130 enum operator op;
131 struct expression *left;
132 struct expression *right;
133 {
134 struct expression *args[2];
135
136 args[0] = left;
137 args[1] = right;
138 return new_exp (2, op, args);
139 }
140
141 static inline struct expression *
new_exp_3(op,bexp,tbranch,fbranch)142 new_exp_3 (op, bexp, tbranch, fbranch)
143 enum operator op;
144 struct expression *bexp;
145 struct expression *tbranch;
146 struct expression *fbranch;
147 {
148 struct expression *args[3];
149
150 args[0] = bexp;
151 args[1] = tbranch;
152 args[2] = fbranch;
153 return new_exp (3, op, args);
154 }
155
156 %}
157
158 /* This declares that all operators have the same associativity and the
159 precedence order as in C. See [Harbison, Steele: C, A Reference Manual].
160 There is no unary minus and no bitwise operators.
161 Operators with the same syntactic behaviour have been merged into a single
162 token, to save space in the array generated by bison. */
163 %right '?' /* ? */
164 %left '|' /* || */
165 %left '&' /* && */
166 %left EQUOP2 /* == != */
167 %left CMPOP2 /* < > <= >= */
168 %left ADDOP2 /* + - */
169 %left MULOP2 /* * / % */
170 %right '!' /* ! */
171
172 %token <op> EQUOP2 CMPOP2 ADDOP2 MULOP2
173 %token <num> NUMBER
174 %type <exp> exp
175
176 %%
177
178 start: exp
179 {
180 if ($1 == NULL)
181 YYABORT;
182 ((struct parse_args *) arg)->res = $1;
183 }
184 ;
185
186 exp: exp '?' exp ':' exp
187 {
188 $$ = new_exp_3 (qmop, $1, $3, $5);
189 }
190 | exp '|' exp
191 {
192 $$ = new_exp_2 (lor, $1, $3);
193 }
194 | exp '&' exp
195 {
196 $$ = new_exp_2 (land, $1, $3);
197 }
198 | exp EQUOP2 exp
199 {
200 $$ = new_exp_2 ($2, $1, $3);
201 }
202 | exp CMPOP2 exp
203 {
204 $$ = new_exp_2 ($2, $1, $3);
205 }
206 | exp ADDOP2 exp
207 {
208 $$ = new_exp_2 ($2, $1, $3);
209 }
210 | exp MULOP2 exp
211 {
212 $$ = new_exp_2 ($2, $1, $3);
213 }
214 | '!' exp
215 {
216 $$ = new_exp_1 (lnot, $2);
217 }
218 | 'n'
219 {
220 $$ = new_exp_0 (var);
221 }
222 | NUMBER
223 {
224 if (($$ = new_exp_0 (num)) != NULL)
225 $$->val.num = $1;
226 }
227 | '(' exp ')'
228 {
229 $$ = $2;
230 }
231 ;
232
233 %%
234
235 void
236 internal_function
FREE_EXPRESSION(exp)237 FREE_EXPRESSION (exp)
238 struct expression *exp;
239 {
240 if (exp == NULL)
241 return;
242
243 /* Handle the recursive case. */
244 switch (exp->nargs)
245 {
246 case 3:
247 FREE_EXPRESSION (exp->val.args[2]);
248 /* FALLTHROUGH */
249 case 2:
250 FREE_EXPRESSION (exp->val.args[1]);
251 /* FALLTHROUGH */
252 case 1:
253 FREE_EXPRESSION (exp->val.args[0]);
254 /* FALLTHROUGH */
255 default:
256 break;
257 }
258
259 free (exp);
260 }
261
262
263 static int
yylex(lval,pexp)264 yylex (lval, pexp)
265 YYSTYPE *lval;
266 const char **pexp;
267 {
268 const char *exp = *pexp;
269 int result;
270
271 while (1)
272 {
273 if (exp[0] == '\0')
274 {
275 *pexp = exp;
276 return YYEOF;
277 }
278
279 if (exp[0] != ' ' && exp[0] != '\t')
280 break;
281
282 ++exp;
283 }
284
285 result = *exp++;
286 switch (result)
287 {
288 case '0': case '1': case '2': case '3': case '4':
289 case '5': case '6': case '7': case '8': case '9':
290 {
291 unsigned long int n = result - '0';
292 while (exp[0] >= '0' && exp[0] <= '9')
293 {
294 n *= 10;
295 n += exp[0] - '0';
296 ++exp;
297 }
298 lval->num = n;
299 result = NUMBER;
300 }
301 break;
302
303 case '=':
304 if (exp[0] == '=')
305 {
306 ++exp;
307 lval->op = equal;
308 result = EQUOP2;
309 }
310 else
311 result = YYERRCODE;
312 break;
313
314 case '!':
315 if (exp[0] == '=')
316 {
317 ++exp;
318 lval->op = not_equal;
319 result = EQUOP2;
320 }
321 break;
322
323 case '&':
324 case '|':
325 if (exp[0] == result)
326 ++exp;
327 else
328 result = YYERRCODE;
329 break;
330
331 case '<':
332 if (exp[0] == '=')
333 {
334 ++exp;
335 lval->op = less_or_equal;
336 }
337 else
338 lval->op = less_than;
339 result = CMPOP2;
340 break;
341
342 case '>':
343 if (exp[0] == '=')
344 {
345 ++exp;
346 lval->op = greater_or_equal;
347 }
348 else
349 lval->op = greater_than;
350 result = CMPOP2;
351 break;
352
353 case '*':
354 lval->op = mult;
355 result = MULOP2;
356 break;
357
358 case '/':
359 lval->op = divide;
360 result = MULOP2;
361 break;
362
363 case '%':
364 lval->op = module;
365 result = MULOP2;
366 break;
367
368 case '+':
369 lval->op = plus;
370 result = ADDOP2;
371 break;
372
373 case '-':
374 lval->op = minus;
375 result = ADDOP2;
376 break;
377
378 case 'n':
379 case '?':
380 case ':':
381 case '(':
382 case ')':
383 /* Nothing, just return the character. */
384 break;
385
386 case ';':
387 case '\n':
388 case '\0':
389 /* Be safe and let the user call this function again. */
390 --exp;
391 result = YYEOF;
392 break;
393
394 default:
395 result = YYERRCODE;
396 #if YYDEBUG != 0
397 --exp;
398 #endif
399 break;
400 }
401
402 *pexp = exp;
403
404 return result;
405 }
406
407
408 static void
yyerror(str)409 yyerror (str)
410 const char *str;
411 {
412 /* Do nothing. We don't print error messages here. */
413 }
414