source: trunk/src/makedep/ifparser.c@ 202

Last change on this file since 202 was 164, checked in by bird, 21 years ago

Initial revision
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1/*
2 * $Xorg: ifparser.c,v 1.3 2000/08/17 19:41:50 cpqbld Exp $
3 *
4 * Copyright 1992 Network Computing Devices, Inc.
5 *
6 * Permission to use, copy, modify, and distribute this software and its
7 * documentation for any purpose and without fee is hereby granted, provided
8 * that the above copyright notice appear in all copies and that both that
9 * copyright notice and this permission notice appear in supporting
10 * documentation, and that the name of Network Computing Devices may not be
11 * used in advertising or publicity pertaining to distribution of the software
12 * without specific, written prior permission. Network Computing Devices makes
13 * no representations about the suitability of this software for any purpose.
14 * It is provided ``as is'' without express or implied warranty.
15 *
16 * NETWORK COMPUTING DEVICES DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
17 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
18 * IN NO EVENT SHALL NETWORK COMPUTING DEVICES BE LIABLE FOR ANY SPECIAL,
19 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
20 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
21 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
22 * PERFORMANCE OF THIS SOFTWARE.
23 *
24 * Author: Jim Fulton
25 * Network Computing Devices, Inc.
26 *
27 * Simple if statement processor
28 *
29 * This module can be used to evaluate string representations of C language
30 * if constructs. It accepts the following grammar:
31 *
32 * EXPRESSION := VALUE
33 * | VALUE BINOP EXPRESSION
34 * | VALUE '?' EXPRESSION ':' EXPRESSION
35 *
36 * VALUE := '(' EXPRESSION ')'
37 * | '!' VALUE
38 * | '-' VALUE
39 * | '+' VALUE
40 * | '~' VALUE
41 * | 'defined' '(' variable ')'
42 * | 'defined' variable
43 * | # variable '(' variable-list ')'
44 * | variable
45 * | number
46 *
47 * BINOP := '*' | '/' | '%'
48 * | '+' | '-'
49 * | '<<' | '>>'
50 * | '<' | '>' | '<=' | '>='
51 * | '==' | '!='
52 * | '&' | '^' | '|'
53 * | '&&' | '||'
54 *
55 * The normal C order of precedence is supported.
56 *
57 *
58 * External Entry Points:
59 *
60 * ParseIfExpression parse a string for #if
61 */
62/* $XFree86: xc/config/makedepend/ifparser.c,v 3.10tsi Exp $ */
63
64#include "ifparser.h"
65#include <ctype.h>
66#include <stdlib.h>
67#include <string.h>
68
69/****************************************************************************
70 Internal Macros and Utilities for Parser
71 ****************************************************************************/
72
73#define DO(val) if (!(val)) return NULL
74#define CALLFUNC(ggg,fff) (*((ggg)->funcs.fff))
75#define SKIPSPACE(ccc) while (isspace(*ccc)) ccc++
76#define isvarfirstletter(ccc) (isalpha(ccc) || (ccc) == '_')
77
78
79static const char *
80parse_variable (IfParser *g, const char *cp, const char **varp)
81{
82 SKIPSPACE (cp);
83
84 if (!isvarfirstletter (*cp))
85 return CALLFUNC(g, handle_error) (g, cp, "variable name");
86
87 *varp = cp;
88 /* EMPTY */
89 for (cp++; isalnum(*cp) || *cp == '_'; cp++) ;
90 return cp;
91}
92
93
94static const char *
95parse_number (IfParser *g, const char *cp, long *valp)
96{
97 long base = 10;
98 SKIPSPACE (cp);
99
100 if (!isdigit(*cp))
101 return CALLFUNC(g, handle_error) (g, cp, "number");
102
103 *valp = 0;
104
105 if (*cp == '0') {
106 cp++;
107 if ((*cp == 'x') || (*cp == 'X')) {
108 base = 16;
109 cp++;
110 } else {
111 base = 8;
112 }
113 }
114
115 /* Ignore overflows and assume ASCII, what source is usually written in */
116 while (1) {
117 int increment = -1;
118 if (base == 8) {
119 if ((*cp >= '0') && (*cp <= '7'))
120 increment = *cp++ - '0';
121 } else if (base == 16) {
122 if ((*cp >= '0') && (*cp <= '9'))
123 increment = *cp++ - '0';
124 else if ((*cp >= 'A') && (*cp <= 'F'))
125 increment = *cp++ - ('A' - 10);
126 else if ((*cp >= 'a') && (*cp <= 'f'))
127 increment = *cp++ - ('a' - 10);
128 } else { /* Decimal */
129 if ((*cp >= '0') && (*cp <= '9'))
130 increment = *cp++ - '0';
131 }
132 if (increment < 0)
133 break;
134 *valp = (*valp * base) + increment;
135 }
136
137 /* Skip trailing qualifiers */
138 while (*cp == 'U' || *cp == 'u' || *cp == 'L' || *cp == 'l') cp++;
139 return cp;
140}
141
142static const char *
143parse_character (IfParser *g, const char *cp, long *valp)
144{
145 char val;
146
147 SKIPSPACE (cp);
148 if (*cp == '\\')
149 switch (cp[1]) {
150 case 'n': val = '\n'; break;
151 case 't': val = '\t'; break;
152 case 'v': val = '\v'; break;
153 case 'b': val = '\b'; break;
154 case 'r': val = '\r'; break;
155 case 'f': val = '\f'; break;
156 case 'a': val = '\a'; break;
157 case '\\': val = '\\'; break;
158 case '?': val = '\?'; break;
159 case '\'': val = '\''; break;
160 case '\"': val = '\"'; break;
161 case 'x': val = (char) strtol (cp + 2, NULL, 16); break;
162 default: val = (char) strtol (cp + 1, NULL, 8); break;
163 }
164 else
165 val = *cp;
166 while (*cp != '\'') cp++;
167 *valp = (long) val;
168 return cp;
169}
170
171static const char *
172parse_value (IfParser *g, const char *cp, long *valp)
173{
174 const char *var, *varend;
175
176 *valp = 0;
177
178 SKIPSPACE (cp);
179 if (!*cp)
180 return cp;
181
182 switch (*cp) {
183 case '(':
184 DO (cp = ParseIfExpression (g, cp + 1, valp));
185 SKIPSPACE (cp);
186 if (*cp != ')')
187 return CALLFUNC(g, handle_error) (g, cp, ")");
188
189 return cp + 1; /* skip the right paren */
190
191 case '!':
192 DO (cp = parse_value (g, cp + 1, valp));
193 *valp = !(*valp);
194 return cp;
195
196 case '-':
197 DO (cp = parse_value (g, cp + 1, valp));
198 *valp = -(*valp);
199 return cp;
200
201 case '+':
202 DO (cp = parse_value (g, cp + 1, valp));
203 return cp;
204
205 case '~':
206 DO (cp = parse_value (g, cp + 1, valp));
207 *valp = ~(*valp);
208 return cp;
209
210 case '#':
211 DO (cp = parse_variable (g, cp + 1, &var));
212 SKIPSPACE (cp);
213 if (*cp != '(')
214 return CALLFUNC(g, handle_error) (g, cp, "(");
215 do {
216 DO (cp = parse_variable (g, cp + 1, &var));
217 SKIPSPACE (cp);
218 } while (*cp && *cp != ')');
219 if (*cp != ')')
220 return CALLFUNC(g, handle_error) (g, cp, ")");
221 *valp = 1; /* XXX */
222 return cp + 1;
223
224 case '\'':
225 DO (cp = parse_character (g, cp + 1, valp));
226 if (*cp != '\'')
227 return CALLFUNC(g, handle_error) (g, cp, "'");
228 return cp + 1;
229
230 case 'd':
231 if (strncmp (cp, "defined", 7) == 0 && !isalnum(cp[7])) {
232 int paren = 0;
233 int len;
234
235 cp += 7;
236 SKIPSPACE (cp);
237 if (*cp == '(') {
238 paren = 1;
239 cp++;
240 }
241 DO (cp = parse_variable (g, cp, &var));
242 len = cp - var;
243 SKIPSPACE (cp);
244 if (paren && *cp != ')')
245 return CALLFUNC(g, handle_error) (g, cp, ")");
246 *valp = (*(g->funcs.eval_defined)) (g, var, len);
247 return cp + paren; /* skip the right paren */
248 }
249 /* fall out */
250 }
251
252 if (isdigit(*cp)) {
253 DO (cp = parse_number (g, cp, valp));
254 } else if (!isvarfirstletter(*cp))
255 return CALLFUNC(g, handle_error) (g, cp, "variable or number");
256 else {
257 DO (cp = parse_variable (g, cp, &var));
258 varend = cp;
259 SKIPSPACE(cp);
260 if (*cp != '(') {
261 *valp = (*(g->funcs.eval_variable)) (g, var, varend - var);
262 } else {
263 do {
264 long dummy;
265 DO (cp = ParseIfExpression (g, cp + 1, &dummy));
266 SKIPSPACE(cp);
267 if (*cp == ')')
268 break;
269 if (*cp != ',')
270 return CALLFUNC(g, handle_error) (g, cp, ",");
271 } while (1);
272
273 *valp = 1; /* XXX */
274 cp++;
275 }
276 }
277
278 return cp;
279}
280
281
282
283static const char *
284parse_product (IfParser *g, const char *cp, long *valp)
285{
286 long rightval;
287
288 DO (cp = parse_value (g, cp, valp));
289 SKIPSPACE (cp);
290
291 switch (*cp) {
292 case '*':
293 DO (cp = parse_product (g, cp + 1, &rightval));
294 *valp = (*valp * rightval);
295 break;
296
297 case '/':
298 DO (cp = parse_product (g, cp + 1, &rightval));
299 *valp = (*valp / rightval);
300 break;
301
302 case '%':
303 DO (cp = parse_product (g, cp + 1, &rightval));
304 *valp = (*valp % rightval);
305 break;
306 }
307 return cp;
308}
309
310
311static const char *
312parse_sum (IfParser *g, const char *cp, long *valp)
313{
314 long rightval;
315
316 DO (cp = parse_product (g, cp, valp));
317 SKIPSPACE (cp);
318
319 switch (*cp) {
320 case '+':
321 DO (cp = parse_sum (g, cp + 1, &rightval));
322 *valp = (*valp + rightval);
323 break;
324
325 case '-':
326 DO (cp = parse_sum (g, cp + 1, &rightval));
327 *valp = (*valp - rightval);
328 break;
329 }
330 return cp;
331}
332
333
334static const char *
335parse_shift (IfParser *g, const char *cp, long *valp)
336{
337 long rightval;
338
339 DO (cp = parse_sum (g, cp, valp));
340 SKIPSPACE (cp);
341
342 switch (*cp) {
343 case '<':
344 if (cp[1] == '<') {
345 DO (cp = parse_shift (g, cp + 2, &rightval));
346 *valp = (*valp << rightval);
347 }
348 break;
349
350 case '>':
351 if (cp[1] == '>') {
352 DO (cp = parse_shift (g, cp + 2, &rightval));
353 *valp = (*valp >> rightval);
354 }
355 break;
356 }
357 return cp;
358}
359
360
361static const char *
362parse_inequality (IfParser *g, const char *cp, long *valp)
363{
364 long rightval;
365
366 DO (cp = parse_shift (g, cp, valp));
367 SKIPSPACE (cp);
368
369 switch (*cp) {
370 case '<':
371 if (cp[1] == '=') {
372 DO (cp = parse_inequality (g, cp + 2, &rightval));
373 *valp = (*valp <= rightval);
374 } else {
375 DO (cp = parse_inequality (g, cp + 1, &rightval));
376 *valp = (*valp < rightval);
377 }
378 break;
379
380 case '>':
381 if (cp[1] == '=') {
382 DO (cp = parse_inequality (g, cp + 2, &rightval));
383 *valp = (*valp >= rightval);
384 } else {
385 DO (cp = parse_inequality (g, cp + 1, &rightval));
386 *valp = (*valp > rightval);
387 }
388 break;
389 }
390 return cp;
391}
392
393
394static const char *
395parse_equality (IfParser *g, const char *cp, long *valp)
396{
397 long rightval;
398
399 DO (cp = parse_inequality (g, cp, valp));
400 SKIPSPACE (cp);
401
402 switch (*cp) {
403 case '=':
404 if (cp[1] == '=')
405 cp++;
406 DO (cp = parse_equality (g, cp + 1, &rightval));
407 *valp = (*valp == rightval);
408 break;
409
410 case '!':
411 if (cp[1] != '=')
412 break;
413 DO (cp = parse_equality (g, cp + 2, &rightval));
414 *valp = (*valp != rightval);
415 break;
416 }
417 return cp;
418}
419
420
421static const char *
422parse_band (IfParser *g, const char *cp, long *valp)
423{
424 long rightval;
425
426 DO (cp = parse_equality (g, cp, valp));
427 SKIPSPACE (cp);
428
429 switch (*cp) {
430 case '&':
431 if (cp[1] != '&') {
432 DO (cp = parse_band (g, cp + 1, &rightval));
433 *valp = (*valp & rightval);
434 }
435 break;
436 }
437 return cp;
438}
439
440
441static const char *
442parse_bxor (IfParser *g, const char *cp, long *valp)
443{
444 long rightval;
445
446 DO (cp = parse_band (g, cp, valp));
447 SKIPSPACE (cp);
448
449 switch (*cp) {
450 case '^':
451 DO (cp = parse_bxor (g, cp + 1, &rightval));
452 *valp = (*valp ^ rightval);
453 break;
454 }
455 return cp;
456}
457
458
459static const char *
460parse_bor (IfParser *g, const char *cp, long *valp)
461{
462 long rightval;
463
464 DO (cp = parse_bxor (g, cp, valp));
465 SKIPSPACE (cp);
466
467 switch (*cp) {
468 case '|':
469 if (cp[1] != '|') {
470 DO (cp = parse_bor (g, cp + 1, &rightval));
471 *valp = (*valp | rightval);
472 }
473 break;
474 }
475 return cp;
476}
477
478
479static const char *
480parse_land (IfParser *g, const char *cp, long *valp)
481{
482 long rightval;
483
484 DO (cp = parse_bor (g, cp, valp));
485 SKIPSPACE (cp);
486
487 switch (*cp) {
488 case '&':
489 if (cp[1] != '&')
490 return CALLFUNC(g, handle_error) (g, cp, "&&");
491 DO (cp = parse_land (g, cp + 2, &rightval));
492 *valp = (*valp && rightval);
493 break;
494 }
495 return cp;
496}
497
498
499static const char *
500parse_lor (IfParser *g, const char *cp, long *valp)
501{
502 long rightval;
503
504 DO (cp = parse_land (g, cp, valp));
505 SKIPSPACE (cp);
506
507 switch (*cp) {
508 case '|':
509 if (cp[1] != '|')
510 return CALLFUNC(g, handle_error) (g, cp, "||");
511 DO (cp = parse_lor (g, cp + 2, &rightval));
512 *valp = (*valp || rightval);
513 break;
514 }
515 return cp;
516}
517
518
519static const char *
520parse_cond(IfParser *g, const char *cp, long *valp)
521{
522 long trueval, falseval;
523
524 DO (cp = parse_lor (g, cp, valp));
525 SKIPSPACE (cp);
526
527 switch (*cp) {
528 case '?':
529 DO (cp = parse_cond (g, cp + 1, &trueval));
530 SKIPSPACE (cp);
531 if (*cp != ':')
532 return CALLFUNC(g, handle_error) (g, cp, ":");
533 DO (cp = parse_cond (g, cp + 1, &falseval));
534 *valp = (*valp ? trueval : falseval);
535 break;
536 }
537 return cp;
538}
539
540
541/****************************************************************************
542 External Entry Points
543 ****************************************************************************/
544
545const char *
546ParseIfExpression (IfParser *g, const char *cp, long *valp)
547{
548 return parse_cond (g, cp, valp);
549}
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