1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: calexpr.c,v 2.41 2022/01/15 02:00:21 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Compute data values using expression parser |
6 |
* |
7 |
* 7/1/85 Greg Ward |
8 |
* |
9 |
* 11/11/85 Made channel input conditional with (INCHAN) compiles. |
10 |
* |
11 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
12 |
* |
13 |
* 1/29/87 Made variables conditional (VARIABLE) |
14 |
* |
15 |
* 5/19/88 Added constant subexpression elimination (RCONST) |
16 |
* |
17 |
* 2/19/03 Eliminated conditional compiles in favor of esupport extern. |
18 |
*/ |
19 |
|
20 |
#include "copyright.h" |
21 |
|
22 |
#include <ctype.h> |
23 |
#include <errno.h> |
24 |
#include <math.h> |
25 |
#include <stdlib.h> |
26 |
|
27 |
#include "rtmisc.h" |
28 |
#include "rtio.h" |
29 |
#include "rterror.h" |
30 |
#include "calcomp.h" |
31 |
|
32 |
#define MAXLINE 256 /* maximum line length */ |
33 |
|
34 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
35 |
|
36 |
#define isdecimal(c) (isdigit(c) | ((c) == '.')) |
37 |
|
38 |
static double euminus(EPNODE *), eargument(EPNODE *), enumber(EPNODE *); |
39 |
static double echannel(EPNODE *); |
40 |
static double eadd(EPNODE *), esubtr(EPNODE *), |
41 |
emult(EPNODE *), edivi(EPNODE *), |
42 |
epow(EPNODE *); |
43 |
static double ebotch(EPNODE *); |
44 |
|
45 |
unsigned int esupport = /* what to support */ |
46 |
E_VARIABLE | E_FUNCTION ; |
47 |
|
48 |
int eofc = 0; /* optional end-of-file character */ |
49 |
int nextc; /* lookahead character */ |
50 |
|
51 |
double (*eoper[])(EPNODE *) = { /* expression operations */ |
52 |
ebotch, |
53 |
evariable, |
54 |
enumber, |
55 |
euminus, |
56 |
echannel, |
57 |
efunc, |
58 |
eargument, |
59 |
ebotch, |
60 |
ebotch, |
61 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
62 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
63 |
emult, |
64 |
eadd, |
65 |
0, |
66 |
esubtr, |
67 |
0, |
68 |
edivi, |
69 |
0,0,0,0,0,0,0,0,0,0, |
70 |
ebotch, |
71 |
0,0, |
72 |
ebotch, |
73 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
74 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
75 |
epow, |
76 |
}; |
77 |
|
78 |
static FILE *infp; /* input file pointer */ |
79 |
static char *linbuf; /* line buffer */ |
80 |
static char *infile; /* input file name */ |
81 |
static int lineno; /* input line number */ |
82 |
static int linepos; /* position in buffer */ |
83 |
|
84 |
|
85 |
EPNODE * |
86 |
eparse( /* parse an expression string */ |
87 |
char *expr |
88 |
) |
89 |
{ |
90 |
EPNODE *ep; |
91 |
|
92 |
initstr(expr, NULL, 0); |
93 |
curfunc = NULL; |
94 |
ep = getE1(); |
95 |
if (nextc != EOF) |
96 |
syntax("unexpected character"); |
97 |
return(ep); |
98 |
} |
99 |
|
100 |
|
101 |
double |
102 |
eval( /* evaluate an expression string */ |
103 |
char *expr |
104 |
) |
105 |
{ |
106 |
int prev_support = esupport; |
107 |
EPNODE *ep; |
108 |
double rval; |
109 |
|
110 |
esupport &= ~E_RCONST; /* don't bother reducing constant expr */ |
111 |
ep = eparse(expr); |
112 |
esupport = prev_support; /* as you were */ |
113 |
rval = evalue(ep); |
114 |
epfree(ep); |
115 |
return(rval); |
116 |
} |
117 |
|
118 |
|
119 |
int |
120 |
epcmp( /* compare two expressions for equivalence */ |
121 |
EPNODE *ep1, |
122 |
EPNODE *ep2 |
123 |
) |
124 |
{ |
125 |
double d; |
126 |
|
127 |
if (ep1->type != ep2->type) |
128 |
return(1); |
129 |
|
130 |
switch (ep1->type) { |
131 |
|
132 |
case VAR: |
133 |
return(ep1->v.ln != ep2->v.ln); |
134 |
|
135 |
case NUM: |
136 |
if (ep2->v.num == 0) |
137 |
return(ep1->v.num != 0); |
138 |
d = ep1->v.num / ep2->v.num; |
139 |
return((d > 1.000000000001) | (d < 0.999999999999)); |
140 |
|
141 |
case CHAN: |
142 |
case ARG: |
143 |
return(ep1->v.chan != ep2->v.chan); |
144 |
|
145 |
case '=': |
146 |
case ':': |
147 |
return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
148 |
|
149 |
case CLKT: |
150 |
case SYM: /* should never get this one */ |
151 |
return(0); |
152 |
|
153 |
default: |
154 |
ep1 = ep1->v.kid; |
155 |
ep2 = ep2->v.kid; |
156 |
while (ep1 != NULL) { |
157 |
if (ep2 == NULL) |
158 |
return(1); |
159 |
if (epcmp(ep1, ep2)) |
160 |
return(1); |
161 |
ep1 = ep1->sibling; |
162 |
ep2 = ep2->sibling; |
163 |
} |
164 |
return(ep2 != NULL); |
165 |
} |
166 |
} |
167 |
|
168 |
|
169 |
void |
170 |
epfree( /* free a parse tree */ |
171 |
EPNODE *epar |
172 |
) |
173 |
{ |
174 |
EPNODE *ep; |
175 |
|
176 |
switch (epar->type) { |
177 |
|
178 |
case VAR: |
179 |
varfree(epar->v.ln); |
180 |
break; |
181 |
|
182 |
case SYM: |
183 |
freestr(epar->v.name); |
184 |
break; |
185 |
|
186 |
case NUM: |
187 |
case CHAN: |
188 |
case ARG: |
189 |
case CLKT: |
190 |
break; |
191 |
|
192 |
default: |
193 |
while ((ep = epar->v.kid) != NULL) { |
194 |
epar->v.kid = ep->sibling; |
195 |
epfree(ep); |
196 |
} |
197 |
break; |
198 |
|
199 |
} |
200 |
|
201 |
efree(epar); |
202 |
} |
203 |
|
204 |
/* the following used to be a switch */ |
205 |
static double |
206 |
eargument( |
207 |
EPNODE *ep |
208 |
) |
209 |
{ |
210 |
return(argument(ep->v.chan)); |
211 |
} |
212 |
|
213 |
static double |
214 |
enumber( |
215 |
EPNODE *ep |
216 |
) |
217 |
{ |
218 |
return(ep->v.num); |
219 |
} |
220 |
|
221 |
static double |
222 |
euminus( |
223 |
EPNODE *ep |
224 |
) |
225 |
{ |
226 |
EPNODE *ep1 = ep->v.kid; |
227 |
|
228 |
return(-evalue(ep1)); |
229 |
} |
230 |
|
231 |
static double |
232 |
echannel( |
233 |
EPNODE *ep |
234 |
) |
235 |
{ |
236 |
return(chanvalue(ep->v.chan)); |
237 |
} |
238 |
|
239 |
static double |
240 |
eadd( |
241 |
EPNODE *ep |
242 |
) |
243 |
{ |
244 |
EPNODE *ep1 = ep->v.kid; |
245 |
|
246 |
return(evalue(ep1) + evalue(ep1->sibling)); |
247 |
} |
248 |
|
249 |
static double |
250 |
esubtr( |
251 |
EPNODE *ep |
252 |
) |
253 |
{ |
254 |
EPNODE *ep1 = ep->v.kid; |
255 |
|
256 |
return(evalue(ep1) - evalue(ep1->sibling)); |
257 |
} |
258 |
|
259 |
static double |
260 |
emult( |
261 |
EPNODE *ep |
262 |
) |
263 |
{ |
264 |
EPNODE *ep1 = ep->v.kid; |
265 |
|
266 |
return(evalue(ep1) * evalue(ep1->sibling)); |
267 |
} |
268 |
|
269 |
static double |
270 |
edivi( |
271 |
EPNODE *ep |
272 |
) |
273 |
{ |
274 |
EPNODE *ep1 = ep->v.kid; |
275 |
double d; |
276 |
|
277 |
d = evalue(ep1->sibling); |
278 |
if (d == 0.0) { |
279 |
wputs("Division by zero\n"); |
280 |
errno = ERANGE; |
281 |
return(0.0); |
282 |
} |
283 |
return(evalue(ep1) / d); |
284 |
} |
285 |
|
286 |
static double |
287 |
epow( |
288 |
EPNODE *ep |
289 |
) |
290 |
{ |
291 |
EPNODE *ep1 = ep->v.kid; |
292 |
double d; |
293 |
int lasterrno; |
294 |
|
295 |
lasterrno = errno; |
296 |
errno = 0; |
297 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
298 |
#ifdef isnan |
299 |
if (errno == 0) { |
300 |
if (isnan(d)) |
301 |
errno = EDOM; |
302 |
else if (isinf(d)) |
303 |
errno = ERANGE; |
304 |
} |
305 |
#endif |
306 |
if ((errno == EDOM) | (errno == ERANGE)) { |
307 |
wputs("Illegal power\n"); |
308 |
return(0.0); |
309 |
} |
310 |
errno = lasterrno; |
311 |
return(d); |
312 |
} |
313 |
|
314 |
static double |
315 |
ebotch( |
316 |
EPNODE *ep |
317 |
) |
318 |
{ |
319 |
eputs("Bad expression!\n"); |
320 |
quit(1); |
321 |
return 0.0; /* pro forma return */ |
322 |
} |
323 |
|
324 |
|
325 |
EPNODE * |
326 |
ekid( /* return pointer to a node's nth kid */ |
327 |
EPNODE *ep, |
328 |
int n |
329 |
) |
330 |
{ |
331 |
|
332 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
333 |
if (--n < 0) |
334 |
break; |
335 |
|
336 |
return(ep); |
337 |
} |
338 |
|
339 |
|
340 |
int |
341 |
nekids( /* return # of kids for node ep */ |
342 |
EPNODE *ep |
343 |
) |
344 |
{ |
345 |
int n = 0; |
346 |
|
347 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
348 |
n++; |
349 |
|
350 |
return(n); |
351 |
} |
352 |
|
353 |
|
354 |
void |
355 |
initfile( /* prepare input file */ |
356 |
FILE *fp, |
357 |
char *fn, |
358 |
int ln |
359 |
) |
360 |
{ |
361 |
static char inpbuf[MAXLINE]; |
362 |
|
363 |
infp = fp; |
364 |
linbuf = inpbuf; |
365 |
infile = fn; |
366 |
lineno = ln; |
367 |
linepos = 0; |
368 |
inpbuf[0] = '\0'; |
369 |
scan(); |
370 |
} |
371 |
|
372 |
|
373 |
void |
374 |
initstr( /* prepare input string */ |
375 |
char *s, |
376 |
char *fn, |
377 |
int ln |
378 |
) |
379 |
{ |
380 |
infp = NULL; |
381 |
infile = fn; |
382 |
lineno = ln; |
383 |
linbuf = s; |
384 |
linepos = 0; |
385 |
scan(); |
386 |
} |
387 |
|
388 |
|
389 |
void |
390 |
getscanpos( /* return current scan position */ |
391 |
char **fnp, |
392 |
int *lnp, |
393 |
char **spp, |
394 |
FILE **fpp |
395 |
) |
396 |
{ |
397 |
if (fnp != NULL) *fnp = infile; |
398 |
if (lnp != NULL) *lnp = lineno; |
399 |
if (spp != NULL) *spp = linbuf+linepos; |
400 |
if (fpp != NULL) *fpp = infp; |
401 |
} |
402 |
|
403 |
|
404 |
int |
405 |
scan(void) /* scan next character, return literal next */ |
406 |
{ |
407 |
int lnext = 0; |
408 |
|
409 |
do { |
410 |
if (linbuf[linepos] == '\0') |
411 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
412 |
nextc = EOF; |
413 |
else { |
414 |
nextc = linbuf[0]; |
415 |
lineno++; |
416 |
linepos = 1; |
417 |
} |
418 |
else |
419 |
nextc = linbuf[linepos++]; |
420 |
if (!lnext) |
421 |
lnext = nextc; |
422 |
if (nextc == eofc) { |
423 |
nextc = EOF; |
424 |
break; |
425 |
} |
426 |
if (nextc == '{') { |
427 |
scan(); |
428 |
while (nextc != '}') |
429 |
if (nextc == EOF) |
430 |
syntax("'}' expected"); |
431 |
else |
432 |
scan(); |
433 |
scan(); |
434 |
} |
435 |
} while (isspace(nextc)); |
436 |
return(lnext); |
437 |
} |
438 |
|
439 |
|
440 |
char * |
441 |
long2ascii( /* convert long to ascii */ |
442 |
long l |
443 |
) |
444 |
{ |
445 |
static char buf[16]; |
446 |
char *cp; |
447 |
int neg = 0; |
448 |
|
449 |
if (l == 0) |
450 |
return("0"); |
451 |
if (l < 0) { |
452 |
l = -l; |
453 |
neg++; |
454 |
} |
455 |
cp = buf + sizeof(buf); |
456 |
*--cp = '\0'; |
457 |
while (l) { |
458 |
*--cp = l % 10 + '0'; |
459 |
l /= 10; |
460 |
} |
461 |
if (neg) |
462 |
*--cp = '-'; |
463 |
return(cp); |
464 |
} |
465 |
|
466 |
|
467 |
void |
468 |
syntax( /* report syntax error and quit */ |
469 |
char *err |
470 |
) |
471 |
{ |
472 |
int i; |
473 |
|
474 |
if ((infile != NULL) | (lineno != 0)) { |
475 |
if (infile != NULL) eputs(infile); |
476 |
if (lineno != 0) { |
477 |
eputs(infile != NULL ? ", line " : "line "); |
478 |
eputs(long2ascii((long)lineno)); |
479 |
} |
480 |
eputs(":\n"); |
481 |
} |
482 |
eputs(linbuf); |
483 |
if (linbuf[strlen(linbuf)-1] != '\n') |
484 |
eputs("\n"); |
485 |
for (i = 0; i < linepos-1; i++) |
486 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
487 |
eputs("^ "); |
488 |
eputs(err); |
489 |
eputs("\n"); |
490 |
quit(1); |
491 |
} |
492 |
|
493 |
|
494 |
void |
495 |
addekid( /* add a child to ep */ |
496 |
EPNODE *ep, |
497 |
EPNODE *ekid |
498 |
) |
499 |
{ |
500 |
if (ep->v.kid == NULL) |
501 |
ep->v.kid = ekid; |
502 |
else { |
503 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
504 |
; |
505 |
ep->sibling = ekid; |
506 |
} |
507 |
ekid->sibling = NULL; |
508 |
} |
509 |
|
510 |
|
511 |
char * |
512 |
getname(void) /* scan an identifier */ |
513 |
{ |
514 |
static char str[RMAXWORD+1]; |
515 |
int i, lnext; |
516 |
|
517 |
lnext = nextc; |
518 |
for (i = 0; i < RMAXWORD && isid(lnext); i++, lnext = scan()) |
519 |
str[i] = lnext; |
520 |
str[i] = '\0'; |
521 |
while (isid(lnext)) /* skip rest of name */ |
522 |
lnext = scan(); |
523 |
|
524 |
return(str); |
525 |
} |
526 |
|
527 |
|
528 |
int |
529 |
getinum(void) /* scan a positive integer */ |
530 |
{ |
531 |
int n, lnext; |
532 |
|
533 |
n = 0; |
534 |
lnext = nextc; |
535 |
while (isdigit(lnext)) { |
536 |
n = n * 10 + lnext - '0'; |
537 |
lnext = scan(); |
538 |
} |
539 |
return(n); |
540 |
} |
541 |
|
542 |
|
543 |
double |
544 |
getnum(void) /* scan a positive float */ |
545 |
{ |
546 |
int i, lnext; |
547 |
char str[RMAXWORD+1]; |
548 |
|
549 |
i = 0; |
550 |
lnext = nextc; |
551 |
while (isdigit(lnext) && i < RMAXWORD) { |
552 |
str[i++] = lnext; |
553 |
lnext = scan(); |
554 |
} |
555 |
if ((lnext == '.') & (i < RMAXWORD)) { |
556 |
str[i++] = lnext; |
557 |
lnext = scan(); |
558 |
if (i == 1 && !isdigit(lnext)) |
559 |
syntax("badly formed number"); |
560 |
while (isdigit(lnext) && i < RMAXWORD) { |
561 |
str[i++] = lnext; |
562 |
lnext = scan(); |
563 |
} |
564 |
} |
565 |
if ((lnext == 'e') | (lnext == 'E') && i < RMAXWORD) { |
566 |
str[i++] = lnext; |
567 |
lnext = scan(); |
568 |
if ((lnext == '-') | (lnext == '+') && i < RMAXWORD) { |
569 |
str[i++] = lnext; |
570 |
lnext = scan(); |
571 |
} |
572 |
if (!isdigit(lnext)) |
573 |
syntax("missing exponent"); |
574 |
while (isdigit(lnext) && i < RMAXWORD) { |
575 |
str[i++] = lnext; |
576 |
lnext = scan(); |
577 |
} |
578 |
} |
579 |
str[i] = '\0'; |
580 |
|
581 |
return(atof(str)); |
582 |
} |
583 |
|
584 |
|
585 |
EPNODE * |
586 |
getE1(void) /* E1 -> E1 ADDOP E2 */ |
587 |
/* E2 */ |
588 |
{ |
589 |
EPNODE *ep1, *ep2; |
590 |
|
591 |
ep1 = getE2(); |
592 |
while ((nextc == '+') | (nextc == '-')) { |
593 |
ep2 = newnode(); |
594 |
ep2->type = nextc; |
595 |
scan(); |
596 |
addekid(ep2, ep1); |
597 |
addekid(ep2, getE2()); |
598 |
if (esupport&E_RCONST && |
599 |
(ep1->type == NUM) & (ep1->sibling->type == NUM)) |
600 |
ep2 = rconst(ep2); |
601 |
ep1 = ep2; |
602 |
} |
603 |
return(ep1); |
604 |
} |
605 |
|
606 |
|
607 |
EPNODE * |
608 |
getE2(void) /* E2 -> E2 MULOP E3 */ |
609 |
/* E3 */ |
610 |
{ |
611 |
EPNODE *ep1, *ep2; |
612 |
|
613 |
ep1 = getE3(); |
614 |
while ((nextc == '*') | (nextc == '/')) { |
615 |
ep2 = newnode(); |
616 |
ep2->type = nextc; |
617 |
scan(); |
618 |
addekid(ep2, ep1); |
619 |
addekid(ep2, getE3()); |
620 |
if (esupport&E_RCONST) { |
621 |
EPNODE *ep3 = ep1->sibling; |
622 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
623 |
ep2 = rconst(ep2); |
624 |
} else if (ep3->type == NUM) { |
625 |
if (ep2->type == '/') { |
626 |
if (ep3->v.num == 0) |
627 |
syntax("divide by zero constant"); |
628 |
ep2->type = '*'; /* for speed */ |
629 |
ep3->v.num = 1./ep3->v.num; |
630 |
} else if (ep3->v.num == 0) { |
631 |
ep1->sibling = NULL; /* (E2 * 0) */ |
632 |
epfree(ep2); |
633 |
ep2 = ep3; |
634 |
} |
635 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
636 |
epfree(ep3); /* (0 * E3) or (0 / E3) */ |
637 |
ep1->sibling = NULL; |
638 |
efree(ep2); |
639 |
ep2 = ep1; |
640 |
} |
641 |
} |
642 |
ep1 = ep2; |
643 |
} |
644 |
return(ep1); |
645 |
} |
646 |
|
647 |
|
648 |
EPNODE * |
649 |
getE3(void) /* E3 -> E4 ^ E3 */ |
650 |
/* E4 */ |
651 |
{ |
652 |
EPNODE *ep1, *ep2; |
653 |
|
654 |
ep1 = getE4(); |
655 |
if (nextc != '^') |
656 |
return(ep1); |
657 |
ep2 = newnode(); |
658 |
ep2->type = nextc; |
659 |
scan(); |
660 |
addekid(ep2, ep1); |
661 |
addekid(ep2, getE3()); |
662 |
if (esupport&E_RCONST) { |
663 |
EPNODE *ep3 = ep1->sibling; |
664 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
665 |
ep2 = rconst(ep2); |
666 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
667 |
epfree(ep3); /* (0 ^ E3) */ |
668 |
ep1->sibling = NULL; |
669 |
efree(ep2); |
670 |
ep2 = ep1; |
671 |
} else if ((ep3->type == NUM && ep3->v.num == 0) | |
672 |
(ep1->type == NUM && ep1->v.num == 1)) { |
673 |
epfree(ep2); /* (E4 ^ 0) or (1 ^ E3) */ |
674 |
ep2 = newnode(); |
675 |
ep2->type = NUM; |
676 |
ep2->v.num = 1; |
677 |
} else if (ep3->type == NUM && ep3->v.num == 1) { |
678 |
efree(ep3); /* (E4 ^ 1) */ |
679 |
ep1->sibling = NULL; |
680 |
efree(ep2); |
681 |
ep2 = ep1; |
682 |
} |
683 |
} |
684 |
return(ep2); |
685 |
} |
686 |
|
687 |
|
688 |
EPNODE * |
689 |
getE4(void) /* E4 -> ADDOP E5 */ |
690 |
/* E5 */ |
691 |
{ |
692 |
EPNODE *ep1, *ep2; |
693 |
|
694 |
if (nextc == '-') { |
695 |
scan(); |
696 |
ep2 = getE5(); |
697 |
if (ep2->type == NUM) { |
698 |
ep2->v.num = -ep2->v.num; |
699 |
return(ep2); |
700 |
} |
701 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
702 |
ep1 = ep2->v.kid; |
703 |
efree(ep2); |
704 |
return(ep1); |
705 |
} |
706 |
ep1 = newnode(); |
707 |
ep1->type = UMINUS; |
708 |
addekid(ep1, ep2); |
709 |
return(ep1); |
710 |
} |
711 |
if (nextc == '+') |
712 |
scan(); |
713 |
return(getE5()); |
714 |
} |
715 |
|
716 |
|
717 |
EPNODE * |
718 |
getE5(void) /* E5 -> (E1) */ |
719 |
/* VAR */ |
720 |
/* NUM */ |
721 |
/* $N */ |
722 |
/* FUNC(E1,..) */ |
723 |
/* ARG */ |
724 |
{ |
725 |
int i; |
726 |
char *nam; |
727 |
EPNODE *ep1, *ep2; |
728 |
|
729 |
if (nextc == '(') { |
730 |
scan(); |
731 |
ep1 = getE1(); |
732 |
if (nextc != ')') |
733 |
syntax("')' expected"); |
734 |
scan(); |
735 |
return(ep1); |
736 |
} |
737 |
|
738 |
if (esupport&E_INCHAN && nextc == '$') { |
739 |
scan(); |
740 |
ep1 = newnode(); |
741 |
ep1->type = CHAN; |
742 |
ep1->v.chan = getinum(); |
743 |
return(ep1); |
744 |
} |
745 |
|
746 |
if (esupport&(E_VARIABLE|E_FUNCTION) && |
747 |
(isalpha(nextc) | (nextc == CNTXMARK))) { |
748 |
nam = getname(); |
749 |
ep1 = NULL; |
750 |
if ((esupport&(E_VARIABLE|E_FUNCTION)) == (E_VARIABLE|E_FUNCTION) |
751 |
&& curfunc != NULL) |
752 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
753 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
754 |
if (!strcmp(ep2->v.name, nam)) { |
755 |
ep1 = newnode(); |
756 |
ep1->type = ARG; |
757 |
ep1->v.chan = i; |
758 |
break; |
759 |
} |
760 |
if (ep1 == NULL) { |
761 |
ep1 = newnode(); |
762 |
ep1->type = VAR; |
763 |
ep1->v.ln = varinsert(nam); |
764 |
} |
765 |
if (esupport&E_FUNCTION && nextc == '(') { |
766 |
ep2 = newnode(); |
767 |
ep2->type = FUNC; |
768 |
addekid(ep2, ep1); |
769 |
ep1 = ep2; |
770 |
do { |
771 |
scan(); |
772 |
addekid(ep1, getE1()); |
773 |
} while (nextc == ','); |
774 |
if (nextc != ')') |
775 |
syntax("')' expected"); |
776 |
scan(); |
777 |
} else if (!(esupport&E_VARIABLE)) |
778 |
syntax("'(' expected"); |
779 |
if (esupport&E_RCONST && isconstvar(ep1)) |
780 |
ep1 = rconst(ep1); |
781 |
return(ep1); |
782 |
} |
783 |
|
784 |
if (isdecimal(nextc)) { |
785 |
ep1 = newnode(); |
786 |
ep1->type = NUM; |
787 |
ep1->v.num = getnum(); |
788 |
return(ep1); |
789 |
} |
790 |
syntax("unexpected character"); |
791 |
return NULL; /* pro forma return */ |
792 |
} |
793 |
|
794 |
|
795 |
EPNODE * |
796 |
rconst( /* reduce a constant expression */ |
797 |
EPNODE *epar |
798 |
) |
799 |
{ |
800 |
EPNODE *ep; |
801 |
|
802 |
ep = newnode(); |
803 |
ep->type = NUM; |
804 |
errno = 0; |
805 |
ep->v.num = evalue(epar); |
806 |
if ((errno == EDOM) | (errno == ERANGE)) |
807 |
syntax("bad constant expression"); |
808 |
epfree(epar); |
809 |
|
810 |
return(ep); |
811 |
} |
812 |
|
813 |
|
814 |
int |
815 |
isconstvar( /* is ep linked to a constant expression? */ |
816 |
EPNODE *ep |
817 |
) |
818 |
{ |
819 |
EPNODE *ep1; |
820 |
|
821 |
if (esupport&E_FUNCTION && ep->type == FUNC) { |
822 |
if (!isconstfun(ep->v.kid)) |
823 |
return(0); |
824 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
825 |
if (ep1->type != NUM && !isconstfun(ep1)) |
826 |
return(0); |
827 |
return(1); |
828 |
} |
829 |
if (ep->type != VAR) |
830 |
return(0); |
831 |
ep1 = ep->v.ln->def; |
832 |
if (ep1 == NULL || ep1->type != ':') |
833 |
return(0); |
834 |
if (esupport&E_FUNCTION && ep1->v.kid->type != SYM) |
835 |
return(0); |
836 |
return(1); |
837 |
} |
838 |
|
839 |
|
840 |
int |
841 |
isconstfun( /* is ep linked to a constant function? */ |
842 |
EPNODE *ep |
843 |
) |
844 |
{ |
845 |
EPNODE *dp; |
846 |
LIBR *lp; |
847 |
|
848 |
if (ep->type != VAR) |
849 |
return(0); |
850 |
if ((dp = ep->v.ln->def) != NULL) { |
851 |
if (dp->v.kid->type == FUNC) |
852 |
return(dp->type == ':'); |
853 |
else |
854 |
return(0); /* don't identify masked library functions */ |
855 |
} |
856 |
if ((lp = ep->v.ln->lib) != NULL) |
857 |
return(lp->atyp == ':'); |
858 |
return(0); |
859 |
} |