1 |
/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ SGI"; |
5 |
#endif |
6 |
|
7 |
/* |
8 |
* Compute data values using expression parser |
9 |
* |
10 |
* 7/1/85 Greg Ward |
11 |
* |
12 |
* 11/11/85 Made channel input conditional with (INCHAN) compiles. |
13 |
* |
14 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
15 |
* |
16 |
* 1/29/87 Made variables conditional (VARIABLE) |
17 |
* |
18 |
* 5/19/88 Added constant subexpression elimination (RCONST) |
19 |
*/ |
20 |
|
21 |
#include <stdio.h> |
22 |
|
23 |
#include <ctype.h> |
24 |
|
25 |
#include <errno.h> |
26 |
|
27 |
#include <math.h> |
28 |
|
29 |
#include "calcomp.h" |
30 |
|
31 |
#define MAXLINE 256 /* maximum line length */ |
32 |
|
33 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
34 |
|
35 |
#define isdecimal(c) (isdigit(c) || (c) == '.') |
36 |
|
37 |
extern char *savestr(); |
38 |
extern char *emalloc(), *ecalloc(); |
39 |
extern EPNODE *curfunc; |
40 |
extern double efunc(), evariable(); |
41 |
static double euminus(), eargument(), enumber(); |
42 |
#ifdef INCHAN |
43 |
static double echannel(); |
44 |
#endif |
45 |
static double eadd(), esubtr(), emult(), edivi(), epow(); |
46 |
static double ebotch(); |
47 |
|
48 |
#ifdef DCL_ATOF |
49 |
extern double atof(); |
50 |
#endif |
51 |
|
52 |
int nextc; /* lookahead character */ |
53 |
|
54 |
double (*eoper[])() = { /* expression operations */ |
55 |
ebotch, |
56 |
#ifdef VARIABLE |
57 |
evariable, |
58 |
#else |
59 |
ebotch, |
60 |
#endif |
61 |
enumber, |
62 |
euminus, |
63 |
#ifdef INCHAN |
64 |
echannel, |
65 |
#else |
66 |
ebotch, |
67 |
#endif |
68 |
#ifdef FUNCTION |
69 |
efunc, |
70 |
eargument, |
71 |
#else |
72 |
ebotch, |
73 |
ebotch, |
74 |
#endif |
75 |
ebotch, |
76 |
ebotch, |
77 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
78 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
79 |
emult, |
80 |
eadd, |
81 |
0, |
82 |
esubtr, |
83 |
0, |
84 |
edivi, |
85 |
0,0,0,0,0,0,0,0,0,0, |
86 |
ebotch, |
87 |
0,0, |
88 |
ebotch, |
89 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
90 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
91 |
epow, |
92 |
}; |
93 |
|
94 |
static FILE *infp; /* input file pointer */ |
95 |
static char *linbuf; /* line buffer */ |
96 |
static char *infile; /* input file name */ |
97 |
static int lineno; /* input line number */ |
98 |
static int linepos; /* position in buffer */ |
99 |
|
100 |
|
101 |
EPNODE * |
102 |
eparse(expr) /* parse an expression string */ |
103 |
char *expr; |
104 |
{ |
105 |
EPNODE *ep; |
106 |
|
107 |
initstr(expr, NULL, 0); |
108 |
#if defined(VARIABLE) && defined(FUNCTION) |
109 |
curfunc = NULL; |
110 |
#endif |
111 |
ep = getE1(); |
112 |
if (nextc != EOF) |
113 |
syntax("unexpected character"); |
114 |
return(ep); |
115 |
} |
116 |
|
117 |
|
118 |
double |
119 |
eval(expr) /* evaluate an expression string */ |
120 |
char *expr; |
121 |
{ |
122 |
register EPNODE *ep; |
123 |
double rval; |
124 |
|
125 |
ep = eparse(expr); |
126 |
rval = evalue(ep); |
127 |
epfree(ep); |
128 |
return(rval); |
129 |
} |
130 |
|
131 |
|
132 |
epcmp(ep1, ep2) /* compare two expressions for equivalence */ |
133 |
register EPNODE *ep1, *ep2; |
134 |
{ |
135 |
double d; |
136 |
|
137 |
if (ep1->type != ep2->type) |
138 |
return(1); |
139 |
|
140 |
switch (ep1->type) { |
141 |
|
142 |
case VAR: |
143 |
return(ep1->v.ln != ep2->v.ln); |
144 |
|
145 |
case NUM: |
146 |
if (ep2->v.num == 0) |
147 |
return(ep1->v.num != 0); |
148 |
d = ep1->v.num / ep2->v.num; |
149 |
return(d > 1.000000000001 | d < 0.999999999999); |
150 |
|
151 |
case CHAN: |
152 |
case ARG: |
153 |
return(ep1->v.chan != ep2->v.chan); |
154 |
|
155 |
case '=': |
156 |
case ':': |
157 |
return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
158 |
|
159 |
case TICK: |
160 |
case SYM: /* should never get this one */ |
161 |
return(0); |
162 |
|
163 |
default: |
164 |
ep1 = ep1->v.kid; |
165 |
ep2 = ep2->v.kid; |
166 |
while (ep1 != NULL) { |
167 |
if (ep2 == NULL) |
168 |
return(1); |
169 |
if (epcmp(ep1, ep2)) |
170 |
return(1); |
171 |
ep1 = ep1->sibling; |
172 |
ep2 = ep2->sibling; |
173 |
} |
174 |
return(ep2 != NULL); |
175 |
} |
176 |
} |
177 |
|
178 |
|
179 |
epfree(epar) /* free a parse tree */ |
180 |
register EPNODE *epar; |
181 |
{ |
182 |
register EPNODE *ep; |
183 |
|
184 |
switch (epar->type) { |
185 |
|
186 |
#if defined(VARIABLE) || defined(FUNCTION) |
187 |
case VAR: |
188 |
varfree(epar->v.ln); |
189 |
break; |
190 |
|
191 |
case SYM: |
192 |
freestr(epar->v.name); |
193 |
break; |
194 |
#endif |
195 |
|
196 |
case NUM: |
197 |
case CHAN: |
198 |
case ARG: |
199 |
case TICK: |
200 |
break; |
201 |
|
202 |
default: |
203 |
while ((ep = epar->v.kid) != NULL) { |
204 |
epar->v.kid = ep->sibling; |
205 |
epfree(ep); |
206 |
} |
207 |
break; |
208 |
|
209 |
} |
210 |
|
211 |
efree((char *)epar); |
212 |
} |
213 |
|
214 |
/* the following used to be a switch */ |
215 |
#ifdef FUNCTION |
216 |
static double |
217 |
eargument(ep) |
218 |
EPNODE *ep; |
219 |
{ |
220 |
return(argument(ep->v.chan)); |
221 |
} |
222 |
#endif |
223 |
|
224 |
static double |
225 |
enumber(ep) |
226 |
EPNODE *ep; |
227 |
{ |
228 |
return(ep->v.num); |
229 |
} |
230 |
|
231 |
static double |
232 |
euminus(ep) |
233 |
EPNODE *ep; |
234 |
{ |
235 |
register EPNODE *ep1 = ep->v.kid; |
236 |
|
237 |
return(-evalue(ep1)); |
238 |
} |
239 |
|
240 |
#ifdef INCHAN |
241 |
static double |
242 |
echannel(ep) |
243 |
EPNODE *ep; |
244 |
{ |
245 |
return(chanvalue(ep->v.chan)); |
246 |
} |
247 |
#endif |
248 |
|
249 |
static double |
250 |
eadd(ep) |
251 |
EPNODE *ep; |
252 |
{ |
253 |
register EPNODE *ep1 = ep->v.kid; |
254 |
|
255 |
return(evalue(ep1) + evalue(ep1->sibling)); |
256 |
} |
257 |
|
258 |
static double |
259 |
esubtr(ep) |
260 |
EPNODE *ep; |
261 |
{ |
262 |
register EPNODE *ep1 = ep->v.kid; |
263 |
|
264 |
return(evalue(ep1) - evalue(ep1->sibling)); |
265 |
} |
266 |
|
267 |
static double |
268 |
emult(ep) |
269 |
EPNODE *ep; |
270 |
{ |
271 |
register EPNODE *ep1 = ep->v.kid; |
272 |
|
273 |
return(evalue(ep1) * evalue(ep1->sibling)); |
274 |
} |
275 |
|
276 |
static double |
277 |
edivi(ep) |
278 |
EPNODE *ep; |
279 |
{ |
280 |
register EPNODE *ep1 = ep->v.kid; |
281 |
double d; |
282 |
|
283 |
d = evalue(ep1->sibling); |
284 |
if (d == 0.0) { |
285 |
wputs("Division by zero\n"); |
286 |
errno = ERANGE; |
287 |
return(0.0); |
288 |
} |
289 |
return(evalue(ep1) / d); |
290 |
} |
291 |
|
292 |
static double |
293 |
epow(ep) |
294 |
EPNODE *ep; |
295 |
{ |
296 |
register EPNODE *ep1 = ep->v.kid; |
297 |
double d; |
298 |
int lasterrno; |
299 |
|
300 |
lasterrno = errno; |
301 |
errno = 0; |
302 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
303 |
#ifdef IEEE |
304 |
if (!finite(d)) |
305 |
errno = EDOM; |
306 |
#endif |
307 |
if (errno) { |
308 |
wputs("Illegal power\n"); |
309 |
return(0.0); |
310 |
} |
311 |
errno = lasterrno; |
312 |
return(d); |
313 |
} |
314 |
|
315 |
static double |
316 |
ebotch(ep) |
317 |
EPNODE *ep; |
318 |
{ |
319 |
eputs("Bad expression!\n"); |
320 |
quit(1); |
321 |
} |
322 |
|
323 |
|
324 |
EPNODE * |
325 |
ekid(ep, n) /* return pointer to a node's nth kid */ |
326 |
register EPNODE *ep; |
327 |
register int n; |
328 |
{ |
329 |
|
330 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
331 |
if (--n < 0) |
332 |
break; |
333 |
|
334 |
return(ep); |
335 |
} |
336 |
|
337 |
|
338 |
int |
339 |
nekids(ep) /* return # of kids for node ep */ |
340 |
register EPNODE *ep; |
341 |
{ |
342 |
register int n = 0; |
343 |
|
344 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
345 |
n++; |
346 |
|
347 |
return(n); |
348 |
} |
349 |
|
350 |
|
351 |
initfile(fp, fn, ln) /* prepare input file */ |
352 |
FILE *fp; |
353 |
char *fn; |
354 |
int ln; |
355 |
{ |
356 |
static char inpbuf[MAXLINE]; |
357 |
|
358 |
infp = fp; |
359 |
linbuf = inpbuf; |
360 |
infile = fn; |
361 |
lineno = ln; |
362 |
linepos = 0; |
363 |
inpbuf[0] = '\0'; |
364 |
scan(); |
365 |
} |
366 |
|
367 |
|
368 |
initstr(s, fn, ln) /* prepare input string */ |
369 |
char *s; |
370 |
char *fn; |
371 |
int ln; |
372 |
{ |
373 |
infp = NULL; |
374 |
infile = fn; |
375 |
lineno = ln; |
376 |
linbuf = s; |
377 |
linepos = 0; |
378 |
scan(); |
379 |
} |
380 |
|
381 |
|
382 |
getscanpos(fnp, lnp, spp, fpp) /* return current scan position */ |
383 |
char **fnp; |
384 |
int *lnp; |
385 |
char **spp; |
386 |
FILE **fpp; |
387 |
{ |
388 |
if (fnp != NULL) *fnp = infile; |
389 |
if (lnp != NULL) *lnp = lineno; |
390 |
if (spp != NULL) *spp = linbuf+linepos; |
391 |
if (fpp != NULL) *fpp = infp; |
392 |
} |
393 |
|
394 |
|
395 |
int |
396 |
scan() /* scan next character, return literal next */ |
397 |
{ |
398 |
register int lnext = 0; |
399 |
|
400 |
do { |
401 |
if (linbuf[linepos] == '\0') |
402 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
403 |
nextc = EOF; |
404 |
else { |
405 |
nextc = linbuf[0]; |
406 |
lineno++; |
407 |
linepos = 1; |
408 |
} |
409 |
else |
410 |
nextc = linbuf[linepos++]; |
411 |
if (!lnext) |
412 |
lnext = nextc; |
413 |
if (nextc == '{') { |
414 |
scan(); |
415 |
while (nextc != '}') |
416 |
if (nextc == EOF) |
417 |
syntax("'}' expected"); |
418 |
else |
419 |
scan(); |
420 |
scan(); |
421 |
} |
422 |
} while (isspace(nextc)); |
423 |
return(lnext); |
424 |
} |
425 |
|
426 |
|
427 |
char * |
428 |
long2ascii(l) /* convert long to ascii */ |
429 |
long l; |
430 |
{ |
431 |
static char buf[16]; |
432 |
register char *cp; |
433 |
int neg = 0; |
434 |
|
435 |
if (l == 0) |
436 |
return("0"); |
437 |
if (l < 0) { |
438 |
l = -l; |
439 |
neg++; |
440 |
} |
441 |
cp = buf + sizeof(buf); |
442 |
*--cp = '\0'; |
443 |
while (l) { |
444 |
*--cp = l % 10 + '0'; |
445 |
l /= 10; |
446 |
} |
447 |
if (neg) |
448 |
*--cp = '-'; |
449 |
return(cp); |
450 |
} |
451 |
|
452 |
|
453 |
syntax(err) /* report syntax error and quit */ |
454 |
char *err; |
455 |
{ |
456 |
register int i; |
457 |
|
458 |
if (infile != NULL || lineno != 0) { |
459 |
if (infile != NULL) eputs(infile); |
460 |
if (lineno != 0) { |
461 |
eputs(infile != NULL ? ", line " : "line "); |
462 |
eputs(long2ascii((long)lineno)); |
463 |
} |
464 |
eputs(":\n"); |
465 |
} |
466 |
eputs(linbuf); |
467 |
if (linbuf[strlen(linbuf)-1] != '\n') |
468 |
eputs("\n"); |
469 |
for (i = 0; i < linepos-1; i++) |
470 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
471 |
eputs("^ "); |
472 |
eputs(err); |
473 |
eputs("\n"); |
474 |
quit(1); |
475 |
} |
476 |
|
477 |
|
478 |
addekid(ep, ekid) /* add a child to ep */ |
479 |
register EPNODE *ep; |
480 |
EPNODE *ekid; |
481 |
{ |
482 |
if (ep->v.kid == NULL) |
483 |
ep->v.kid = ekid; |
484 |
else { |
485 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
486 |
; |
487 |
ep->sibling = ekid; |
488 |
} |
489 |
ekid->sibling = NULL; |
490 |
} |
491 |
|
492 |
|
493 |
#if defined(VARIABLE) || defined(FUNCTION) |
494 |
char * |
495 |
getname() /* scan an identifier */ |
496 |
{ |
497 |
static char str[MAXWORD+1]; |
498 |
register int i, lnext; |
499 |
|
500 |
lnext = nextc; |
501 |
for (i = 0; i < MAXWORD && isid(lnext); i++, lnext = scan()) |
502 |
str[i] = lnext; |
503 |
str[i] = '\0'; |
504 |
while (isid(lnext)) /* skip rest of name */ |
505 |
lnext = scan(); |
506 |
|
507 |
return(str); |
508 |
} |
509 |
#endif |
510 |
|
511 |
|
512 |
int |
513 |
getinum() /* scan a positive integer */ |
514 |
{ |
515 |
register int n, lnext; |
516 |
|
517 |
n = 0; |
518 |
lnext = nextc; |
519 |
while (isdigit(lnext)) { |
520 |
n = n * 10 + lnext - '0'; |
521 |
lnext = scan(); |
522 |
} |
523 |
return(n); |
524 |
} |
525 |
|
526 |
|
527 |
double |
528 |
getnum() /* scan a positive float */ |
529 |
{ |
530 |
register int i, lnext; |
531 |
char str[MAXWORD+1]; |
532 |
|
533 |
i = 0; |
534 |
lnext = nextc; |
535 |
while (isdigit(lnext) && i < MAXWORD) { |
536 |
str[i++] = lnext; |
537 |
lnext = scan(); |
538 |
} |
539 |
if (lnext == '.' && i < MAXWORD) { |
540 |
str[i++] = lnext; |
541 |
lnext = scan(); |
542 |
if (i == 1 && !isdigit(lnext)) |
543 |
syntax("badly formed number"); |
544 |
while (isdigit(lnext) && i < MAXWORD) { |
545 |
str[i++] = lnext; |
546 |
lnext = scan(); |
547 |
} |
548 |
} |
549 |
if ((lnext == 'e' | lnext == 'E') && i < MAXWORD) { |
550 |
str[i++] = lnext; |
551 |
lnext = scan(); |
552 |
if ((lnext == '-' | lnext == '+') && i < MAXWORD) { |
553 |
str[i++] = lnext; |
554 |
lnext = scan(); |
555 |
} |
556 |
if (!isdigit(lnext)) |
557 |
syntax("missing exponent"); |
558 |
while (isdigit(lnext) && i < MAXWORD) { |
559 |
str[i++] = lnext; |
560 |
lnext = scan(); |
561 |
} |
562 |
} |
563 |
str[i] = '\0'; |
564 |
|
565 |
return(atof(str)); |
566 |
} |
567 |
|
568 |
|
569 |
EPNODE * |
570 |
getE1() /* E1 -> E1 ADDOP E2 */ |
571 |
/* E2 */ |
572 |
{ |
573 |
register EPNODE *ep1, *ep2; |
574 |
|
575 |
ep1 = getE2(); |
576 |
while (nextc == '+' || nextc == '-') { |
577 |
ep2 = newnode(); |
578 |
ep2->type = nextc; |
579 |
scan(); |
580 |
addekid(ep2, ep1); |
581 |
addekid(ep2, getE2()); |
582 |
#ifdef RCONST |
583 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
584 |
ep2 = rconst(ep2); |
585 |
#endif |
586 |
ep1 = ep2; |
587 |
} |
588 |
return(ep1); |
589 |
} |
590 |
|
591 |
|
592 |
EPNODE * |
593 |
getE2() /* E2 -> E2 MULOP E3 */ |
594 |
/* E3 */ |
595 |
{ |
596 |
register EPNODE *ep1, *ep2; |
597 |
|
598 |
ep1 = getE3(); |
599 |
while (nextc == '*' || nextc == '/') { |
600 |
ep2 = newnode(); |
601 |
ep2->type = nextc; |
602 |
scan(); |
603 |
addekid(ep2, ep1); |
604 |
addekid(ep2, getE3()); |
605 |
#ifdef RCONST |
606 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
607 |
ep2 = rconst(ep2); |
608 |
#endif |
609 |
ep1 = ep2; |
610 |
} |
611 |
return(ep1); |
612 |
} |
613 |
|
614 |
|
615 |
EPNODE * |
616 |
getE3() /* E3 -> E4 ^ E3 */ |
617 |
/* E4 */ |
618 |
{ |
619 |
register EPNODE *ep1, *ep2; |
620 |
|
621 |
ep1 = getE4(); |
622 |
if (nextc == '^') { |
623 |
ep2 = newnode(); |
624 |
ep2->type = nextc; |
625 |
scan(); |
626 |
addekid(ep2, ep1); |
627 |
addekid(ep2, getE3()); |
628 |
#ifdef RCONST |
629 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
630 |
ep2 = rconst(ep2); |
631 |
#endif |
632 |
return(ep2); |
633 |
} |
634 |
return(ep1); |
635 |
} |
636 |
|
637 |
|
638 |
EPNODE * |
639 |
getE4() /* E4 -> ADDOP E5 */ |
640 |
/* E5 */ |
641 |
{ |
642 |
register EPNODE *ep1, *ep2; |
643 |
|
644 |
if (nextc == '-') { |
645 |
scan(); |
646 |
ep2 = getE5(); |
647 |
if (ep2->type == NUM) { |
648 |
ep2->v.num = -ep2->v.num; |
649 |
return(ep2); |
650 |
} |
651 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
652 |
efree((char *)ep2); |
653 |
return(ep2->v.kid); |
654 |
} |
655 |
ep1 = newnode(); |
656 |
ep1->type = UMINUS; |
657 |
addekid(ep1, ep2); |
658 |
return(ep1); |
659 |
} |
660 |
if (nextc == '+') |
661 |
scan(); |
662 |
return(getE5()); |
663 |
} |
664 |
|
665 |
|
666 |
EPNODE * |
667 |
getE5() /* E5 -> (E1) */ |
668 |
/* VAR */ |
669 |
/* NUM */ |
670 |
/* $N */ |
671 |
/* FUNC(E1,..) */ |
672 |
/* ARG */ |
673 |
{ |
674 |
int i; |
675 |
char *nam; |
676 |
register EPNODE *ep1, *ep2; |
677 |
|
678 |
if (nextc == '(') { |
679 |
scan(); |
680 |
ep1 = getE1(); |
681 |
if (nextc != ')') |
682 |
syntax("')' expected"); |
683 |
scan(); |
684 |
return(ep1); |
685 |
} |
686 |
|
687 |
#ifdef INCHAN |
688 |
if (nextc == '$') { |
689 |
scan(); |
690 |
ep1 = newnode(); |
691 |
ep1->type = CHAN; |
692 |
ep1->v.chan = getinum(); |
693 |
return(ep1); |
694 |
} |
695 |
#endif |
696 |
|
697 |
#if defined(VARIABLE) || defined(FUNCTION) |
698 |
if (isalpha(nextc) || nextc == CNTXMARK) { |
699 |
nam = getname(); |
700 |
#if defined(VARIABLE) && defined(FUNCTION) |
701 |
ep1 = NULL; |
702 |
if (curfunc != NULL) |
703 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
704 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
705 |
if (!strcmp(ep2->v.name, nam)) { |
706 |
ep1 = newnode(); |
707 |
ep1->type = ARG; |
708 |
ep1->v.chan = i; |
709 |
break; |
710 |
} |
711 |
if (ep1 == NULL) |
712 |
#endif |
713 |
{ |
714 |
ep1 = newnode(); |
715 |
ep1->type = VAR; |
716 |
ep1->v.ln = varinsert(nam); |
717 |
} |
718 |
#ifdef FUNCTION |
719 |
if (nextc == '(') { |
720 |
ep2 = newnode(); |
721 |
ep2->type = FUNC; |
722 |
addekid(ep2, ep1); |
723 |
ep1 = ep2; |
724 |
do { |
725 |
scan(); |
726 |
addekid(ep1, getE1()); |
727 |
} while (nextc == ','); |
728 |
if (nextc != ')') |
729 |
syntax("')' expected"); |
730 |
scan(); |
731 |
} |
732 |
#ifndef VARIABLE |
733 |
else |
734 |
syntax("'(' expected"); |
735 |
#endif |
736 |
#endif |
737 |
#ifdef RCONST |
738 |
if (isconstvar(ep1)) |
739 |
ep1 = rconst(ep1); |
740 |
#endif |
741 |
return(ep1); |
742 |
} |
743 |
#endif |
744 |
|
745 |
if (isdecimal(nextc)) { |
746 |
ep1 = newnode(); |
747 |
ep1->type = NUM; |
748 |
ep1->v.num = getnum(); |
749 |
return(ep1); |
750 |
} |
751 |
syntax("unexpected character"); |
752 |
} |
753 |
|
754 |
|
755 |
#ifdef RCONST |
756 |
EPNODE * |
757 |
rconst(epar) /* reduce a constant expression */ |
758 |
register EPNODE *epar; |
759 |
{ |
760 |
register EPNODE *ep; |
761 |
|
762 |
ep = newnode(); |
763 |
ep->type = NUM; |
764 |
errno = 0; |
765 |
ep->v.num = evalue(epar); |
766 |
if (errno) |
767 |
syntax("bad constant expression"); |
768 |
epfree(epar); |
769 |
|
770 |
return(ep); |
771 |
} |
772 |
|
773 |
|
774 |
isconstvar(ep) /* is ep linked to a constant expression? */ |
775 |
register EPNODE *ep; |
776 |
{ |
777 |
#ifdef VARIABLE |
778 |
register EPNODE *ep1; |
779 |
#ifdef FUNCTION |
780 |
|
781 |
if (ep->type == FUNC) { |
782 |
if (!isconstfun(ep->v.kid)) |
783 |
return(0); |
784 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
785 |
if (ep1->type != NUM && !isconstfun(ep1)) |
786 |
return(0); |
787 |
return(1); |
788 |
} |
789 |
#endif |
790 |
if (ep->type != VAR) |
791 |
return(0); |
792 |
ep1 = ep->v.ln->def; |
793 |
if (ep1 == NULL || ep1->type != ':') |
794 |
return(0); |
795 |
#ifdef FUNCTION |
796 |
if (ep1->v.kid->type != SYM) |
797 |
return(0); |
798 |
#endif |
799 |
return(1); |
800 |
#else |
801 |
return(ep->type == FUNC); |
802 |
#endif |
803 |
} |
804 |
|
805 |
|
806 |
#if defined(FUNCTION) && defined(VARIABLE) |
807 |
isconstfun(ep) /* is ep linked to a constant function? */ |
808 |
register EPNODE *ep; |
809 |
{ |
810 |
register EPNODE *dp; |
811 |
register LIBR *lp; |
812 |
|
813 |
if (ep->type != VAR) |
814 |
return(0); |
815 |
if ((dp = ep->v.ln->def) != NULL && dp->v.kid->type == FUNC) |
816 |
return(dp->type == ':'); |
817 |
if ((lp = ep->v.ln->lib) != NULL) |
818 |
return(lp->atyp == ':'); |
819 |
return(0); |
820 |
} |
821 |
#endif |
822 |
#endif |