1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: calexpr.c,v 2.35 2010/09/04 19:04:35 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 <stdio.h> |
23 |
#include <string.h> |
24 |
#include <ctype.h> |
25 |
#include <errno.h> |
26 |
#include <math.h> |
27 |
#include <stdlib.h> |
28 |
|
29 |
#include "rtmisc.h" |
30 |
#include "rtio.h" |
31 |
#include "rterror.h" |
32 |
#include "calcomp.h" |
33 |
|
34 |
#define MAXLINE 256 /* maximum line length */ |
35 |
|
36 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
37 |
|
38 |
#define isdecimal(c) (isdigit(c) || (c) == '.') |
39 |
|
40 |
static double euminus(EPNODE *), eargument(EPNODE *), enumber(EPNODE *); |
41 |
static double echannel(EPNODE *); |
42 |
static double eadd(EPNODE *), esubtr(EPNODE *), |
43 |
emult(EPNODE *), edivi(EPNODE *), |
44 |
epow(EPNODE *); |
45 |
static double ebotch(EPNODE *); |
46 |
|
47 |
unsigned int esupport = /* what to support */ |
48 |
E_VARIABLE | E_FUNCTION ; |
49 |
|
50 |
int eofc = 0; /* optional end-of-file character */ |
51 |
int nextc; /* lookahead character */ |
52 |
|
53 |
double (*eoper[])(EPNODE *) = { /* expression operations */ |
54 |
ebotch, |
55 |
evariable, |
56 |
enumber, |
57 |
euminus, |
58 |
echannel, |
59 |
efunc, |
60 |
eargument, |
61 |
ebotch, |
62 |
ebotch, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
64 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
65 |
emult, |
66 |
eadd, |
67 |
0, |
68 |
esubtr, |
69 |
0, |
70 |
edivi, |
71 |
0,0,0,0,0,0,0,0,0,0, |
72 |
ebotch, |
73 |
0,0, |
74 |
ebotch, |
75 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
76 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
77 |
epow, |
78 |
}; |
79 |
|
80 |
static FILE *infp; /* input file pointer */ |
81 |
static char *linbuf; /* line buffer */ |
82 |
static char *infile; /* input file name */ |
83 |
static int lineno; /* input line number */ |
84 |
static int linepos; /* position in buffer */ |
85 |
|
86 |
|
87 |
EPNODE * |
88 |
eparse( /* parse an expression string */ |
89 |
char *expr |
90 |
) |
91 |
{ |
92 |
EPNODE *ep; |
93 |
|
94 |
initstr(expr, NULL, 0); |
95 |
curfunc = NULL; |
96 |
ep = getE1(); |
97 |
if (nextc != EOF) |
98 |
syntax("unexpected character"); |
99 |
return(ep); |
100 |
} |
101 |
|
102 |
|
103 |
double |
104 |
eval( /* evaluate an expression string */ |
105 |
char *expr |
106 |
) |
107 |
{ |
108 |
register EPNODE *ep; |
109 |
double rval; |
110 |
|
111 |
ep = eparse(expr); |
112 |
rval = evalue(ep); |
113 |
epfree(ep); |
114 |
return(rval); |
115 |
} |
116 |
|
117 |
|
118 |
int |
119 |
epcmp( /* compare two expressions for equivalence */ |
120 |
register EPNODE *ep1, |
121 |
register EPNODE *ep2 |
122 |
) |
123 |
{ |
124 |
double d; |
125 |
|
126 |
if (ep1->type != ep2->type) |
127 |
return(1); |
128 |
|
129 |
switch (ep1->type) { |
130 |
|
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case VAR: |
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return(ep1->v.ln != ep2->v.ln); |
133 |
|
134 |
case NUM: |
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if (ep2->v.num == 0) |
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return(ep1->v.num != 0); |
137 |
d = ep1->v.num / ep2->v.num; |
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return((d > 1.000000000001) | (d < 0.999999999999)); |
139 |
|
140 |
case CHAN: |
141 |
case ARG: |
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return(ep1->v.chan != ep2->v.chan); |
143 |
|
144 |
case '=': |
145 |
case ':': |
146 |
return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
147 |
|
148 |
case CLKT: |
149 |
case SYM: /* should never get this one */ |
150 |
return(0); |
151 |
|
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default: |
153 |
ep1 = ep1->v.kid; |
154 |
ep2 = ep2->v.kid; |
155 |
while (ep1 != NULL) { |
156 |
if (ep2 == NULL) |
157 |
return(1); |
158 |
if (epcmp(ep1, ep2)) |
159 |
return(1); |
160 |
ep1 = ep1->sibling; |
161 |
ep2 = ep2->sibling; |
162 |
} |
163 |
return(ep2 != NULL); |
164 |
} |
165 |
} |
166 |
|
167 |
|
168 |
void |
169 |
epfree( /* free a parse tree */ |
170 |
register EPNODE *epar |
171 |
) |
172 |
{ |
173 |
register EPNODE *ep; |
174 |
|
175 |
switch (epar->type) { |
176 |
|
177 |
case VAR: |
178 |
varfree(epar->v.ln); |
179 |
break; |
180 |
|
181 |
case SYM: |
182 |
freestr(epar->v.name); |
183 |
break; |
184 |
|
185 |
case NUM: |
186 |
case CHAN: |
187 |
case ARG: |
188 |
case CLKT: |
189 |
break; |
190 |
|
191 |
default: |
192 |
while ((ep = epar->v.kid) != NULL) { |
193 |
epar->v.kid = ep->sibling; |
194 |
epfree(ep); |
195 |
} |
196 |
break; |
197 |
|
198 |
} |
199 |
|
200 |
efree((char *)epar); |
201 |
} |
202 |
|
203 |
/* the following used to be a switch */ |
204 |
static double |
205 |
eargument( |
206 |
EPNODE *ep |
207 |
) |
208 |
{ |
209 |
return(argument(ep->v.chan)); |
210 |
} |
211 |
|
212 |
static double |
213 |
enumber( |
214 |
EPNODE *ep |
215 |
) |
216 |
{ |
217 |
return(ep->v.num); |
218 |
} |
219 |
|
220 |
static double |
221 |
euminus( |
222 |
EPNODE *ep |
223 |
) |
224 |
{ |
225 |
register EPNODE *ep1 = ep->v.kid; |
226 |
|
227 |
return(-evalue(ep1)); |
228 |
} |
229 |
|
230 |
static double |
231 |
echannel( |
232 |
EPNODE *ep |
233 |
) |
234 |
{ |
235 |
return(chanvalue(ep->v.chan)); |
236 |
} |
237 |
|
238 |
static double |
239 |
eadd( |
240 |
EPNODE *ep |
241 |
) |
242 |
{ |
243 |
register EPNODE *ep1 = ep->v.kid; |
244 |
|
245 |
return(evalue(ep1) + evalue(ep1->sibling)); |
246 |
} |
247 |
|
248 |
static double |
249 |
esubtr( |
250 |
EPNODE *ep |
251 |
) |
252 |
{ |
253 |
register EPNODE *ep1 = ep->v.kid; |
254 |
|
255 |
return(evalue(ep1) - evalue(ep1->sibling)); |
256 |
} |
257 |
|
258 |
static double |
259 |
emult( |
260 |
EPNODE *ep |
261 |
) |
262 |
{ |
263 |
register EPNODE *ep1 = ep->v.kid; |
264 |
|
265 |
return(evalue(ep1) * evalue(ep1->sibling)); |
266 |
} |
267 |
|
268 |
static double |
269 |
edivi( |
270 |
EPNODE *ep |
271 |
) |
272 |
{ |
273 |
register EPNODE *ep1 = ep->v.kid; |
274 |
double d; |
275 |
|
276 |
d = evalue(ep1->sibling); |
277 |
if (d == 0.0) { |
278 |
wputs("Division by zero\n"); |
279 |
errno = ERANGE; |
280 |
return(0.0); |
281 |
} |
282 |
return(evalue(ep1) / d); |
283 |
} |
284 |
|
285 |
static double |
286 |
epow( |
287 |
EPNODE *ep |
288 |
) |
289 |
{ |
290 |
register EPNODE *ep1 = ep->v.kid; |
291 |
double d; |
292 |
int lasterrno; |
293 |
|
294 |
lasterrno = errno; |
295 |
errno = 0; |
296 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
297 |
#ifdef isnan |
298 |
if (errno == 0) { |
299 |
if (isnan(d)) |
300 |
errno = EDOM; |
301 |
else if (isinf(d)) |
302 |
errno = ERANGE; |
303 |
} |
304 |
#endif |
305 |
if (errno == EDOM || errno == ERANGE) { |
306 |
wputs("Illegal power\n"); |
307 |
return(0.0); |
308 |
} |
309 |
errno = lasterrno; |
310 |
return(d); |
311 |
} |
312 |
|
313 |
static double |
314 |
ebotch( |
315 |
EPNODE *ep |
316 |
) |
317 |
{ |
318 |
eputs("Bad expression!\n"); |
319 |
quit(1); |
320 |
return 0.0; /* pro forma return */ |
321 |
} |
322 |
|
323 |
|
324 |
EPNODE * |
325 |
ekid( /* return pointer to a node's nth kid */ |
326 |
register EPNODE *ep, |
327 |
register int n |
328 |
) |
329 |
{ |
330 |
|
331 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
332 |
if (--n < 0) |
333 |
break; |
334 |
|
335 |
return(ep); |
336 |
} |
337 |
|
338 |
|
339 |
int |
340 |
nekids( /* return # of kids for node ep */ |
341 |
register EPNODE *ep |
342 |
) |
343 |
{ |
344 |
register int n = 0; |
345 |
|
346 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
347 |
n++; |
348 |
|
349 |
return(n); |
350 |
} |
351 |
|
352 |
|
353 |
void |
354 |
initfile( /* prepare input file */ |
355 |
FILE *fp, |
356 |
char *fn, |
357 |
int ln |
358 |
) |
359 |
{ |
360 |
static char inpbuf[MAXLINE]; |
361 |
|
362 |
infp = fp; |
363 |
linbuf = inpbuf; |
364 |
infile = fn; |
365 |
lineno = ln; |
366 |
linepos = 0; |
367 |
inpbuf[0] = '\0'; |
368 |
scan(); |
369 |
} |
370 |
|
371 |
|
372 |
void |
373 |
initstr( /* prepare input string */ |
374 |
char *s, |
375 |
char *fn, |
376 |
int ln |
377 |
) |
378 |
{ |
379 |
infp = NULL; |
380 |
infile = fn; |
381 |
lineno = ln; |
382 |
linbuf = s; |
383 |
linepos = 0; |
384 |
scan(); |
385 |
} |
386 |
|
387 |
|
388 |
void |
389 |
getscanpos( /* return current scan position */ |
390 |
char **fnp, |
391 |
int *lnp, |
392 |
char **spp, |
393 |
FILE **fpp |
394 |
) |
395 |
{ |
396 |
if (fnp != NULL) *fnp = infile; |
397 |
if (lnp != NULL) *lnp = lineno; |
398 |
if (spp != NULL) *spp = linbuf+linepos; |
399 |
if (fpp != NULL) *fpp = infp; |
400 |
} |
401 |
|
402 |
|
403 |
int |
404 |
scan(void) /* scan next character, return literal next */ |
405 |
{ |
406 |
register int lnext = 0; |
407 |
|
408 |
do { |
409 |
if (linbuf[linepos] == '\0') |
410 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
411 |
nextc = EOF; |
412 |
else { |
413 |
nextc = linbuf[0]; |
414 |
lineno++; |
415 |
linepos = 1; |
416 |
} |
417 |
else |
418 |
nextc = linbuf[linepos++]; |
419 |
if (!lnext) |
420 |
lnext = nextc; |
421 |
if (nextc == eofc) { |
422 |
nextc = EOF; |
423 |
break; |
424 |
} |
425 |
if (nextc == '{') { |
426 |
scan(); |
427 |
while (nextc != '}') |
428 |
if (nextc == EOF) |
429 |
syntax("'}' expected"); |
430 |
else |
431 |
scan(); |
432 |
scan(); |
433 |
} |
434 |
} while (isspace(nextc)); |
435 |
return(lnext); |
436 |
} |
437 |
|
438 |
|
439 |
char * |
440 |
long2ascii( /* convert long to ascii */ |
441 |
long l |
442 |
) |
443 |
{ |
444 |
static char buf[16]; |
445 |
register char *cp; |
446 |
int neg = 0; |
447 |
|
448 |
if (l == 0) |
449 |
return("0"); |
450 |
if (l < 0) { |
451 |
l = -l; |
452 |
neg++; |
453 |
} |
454 |
cp = buf + sizeof(buf); |
455 |
*--cp = '\0'; |
456 |
while (l) { |
457 |
*--cp = l % 10 + '0'; |
458 |
l /= 10; |
459 |
} |
460 |
if (neg) |
461 |
*--cp = '-'; |
462 |
return(cp); |
463 |
} |
464 |
|
465 |
|
466 |
void |
467 |
syntax( /* report syntax error and quit */ |
468 |
char *err |
469 |
) |
470 |
{ |
471 |
register int i; |
472 |
|
473 |
if (infile != NULL || lineno != 0) { |
474 |
if (infile != NULL) eputs(infile); |
475 |
if (lineno != 0) { |
476 |
eputs(infile != NULL ? ", line " : "line "); |
477 |
eputs(long2ascii((long)lineno)); |
478 |
} |
479 |
eputs(":\n"); |
480 |
} |
481 |
eputs(linbuf); |
482 |
if (linbuf[strlen(linbuf)-1] != '\n') |
483 |
eputs("\n"); |
484 |
for (i = 0; i < linepos-1; i++) |
485 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
486 |
eputs("^ "); |
487 |
eputs(err); |
488 |
eputs("\n"); |
489 |
quit(1); |
490 |
} |
491 |
|
492 |
|
493 |
void |
494 |
addekid( /* add a child to ep */ |
495 |
register EPNODE *ep, |
496 |
EPNODE *ekid |
497 |
) |
498 |
{ |
499 |
if (ep->v.kid == NULL) |
500 |
ep->v.kid = ekid; |
501 |
else { |
502 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
503 |
; |
504 |
ep->sibling = ekid; |
505 |
} |
506 |
ekid->sibling = NULL; |
507 |
} |
508 |
|
509 |
|
510 |
char * |
511 |
getname(void) /* scan an identifier */ |
512 |
{ |
513 |
static char str[RMAXWORD+1]; |
514 |
register int i, lnext; |
515 |
|
516 |
lnext = nextc; |
517 |
for (i = 0; i < RMAXWORD && isid(lnext); i++, lnext = scan()) |
518 |
str[i] = lnext; |
519 |
str[i] = '\0'; |
520 |
while (isid(lnext)) /* skip rest of name */ |
521 |
lnext = scan(); |
522 |
|
523 |
return(str); |
524 |
} |
525 |
|
526 |
|
527 |
int |
528 |
getinum(void) /* scan a positive integer */ |
529 |
{ |
530 |
register int n, lnext; |
531 |
|
532 |
n = 0; |
533 |
lnext = nextc; |
534 |
while (isdigit(lnext)) { |
535 |
n = n * 10 + lnext - '0'; |
536 |
lnext = scan(); |
537 |
} |
538 |
return(n); |
539 |
} |
540 |
|
541 |
|
542 |
double |
543 |
getnum(void) /* scan a positive float */ |
544 |
{ |
545 |
register int i, lnext; |
546 |
char str[RMAXWORD+1]; |
547 |
|
548 |
i = 0; |
549 |
lnext = nextc; |
550 |
while (isdigit(lnext) && i < RMAXWORD) { |
551 |
str[i++] = lnext; |
552 |
lnext = scan(); |
553 |
} |
554 |
if (lnext == '.' && i < RMAXWORD) { |
555 |
str[i++] = lnext; |
556 |
lnext = scan(); |
557 |
if (i == 1 && !isdigit(lnext)) |
558 |
syntax("badly formed number"); |
559 |
while (isdigit(lnext) && i < RMAXWORD) { |
560 |
str[i++] = lnext; |
561 |
lnext = scan(); |
562 |
} |
563 |
} |
564 |
if ((lnext == 'e') | (lnext == 'E') && i < RMAXWORD) { |
565 |
str[i++] = lnext; |
566 |
lnext = scan(); |
567 |
if ((lnext == '-') | (lnext == '+') && i < RMAXWORD) { |
568 |
str[i++] = lnext; |
569 |
lnext = scan(); |
570 |
} |
571 |
if (!isdigit(lnext)) |
572 |
syntax("missing exponent"); |
573 |
while (isdigit(lnext) && i < RMAXWORD) { |
574 |
str[i++] = lnext; |
575 |
lnext = scan(); |
576 |
} |
577 |
} |
578 |
str[i] = '\0'; |
579 |
|
580 |
return(atof(str)); |
581 |
} |
582 |
|
583 |
|
584 |
EPNODE * |
585 |
getE1(void) /* E1 -> E1 ADDOP E2 */ |
586 |
/* E2 */ |
587 |
{ |
588 |
register EPNODE *ep1, *ep2; |
589 |
|
590 |
ep1 = getE2(); |
591 |
while (nextc == '+' || nextc == '-') { |
592 |
ep2 = newnode(); |
593 |
ep2->type = nextc; |
594 |
scan(); |
595 |
addekid(ep2, ep1); |
596 |
addekid(ep2, getE2()); |
597 |
if (esupport&E_RCONST && |
598 |
ep1->type == NUM && ep1->sibling->type == NUM) |
599 |
ep2 = rconst(ep2); |
600 |
ep1 = ep2; |
601 |
} |
602 |
return(ep1); |
603 |
} |
604 |
|
605 |
|
606 |
EPNODE * |
607 |
getE2(void) /* E2 -> E2 MULOP E3 */ |
608 |
/* E3 */ |
609 |
{ |
610 |
register EPNODE *ep1, *ep2; |
611 |
|
612 |
ep1 = getE3(); |
613 |
while (nextc == '*' || nextc == '/') { |
614 |
ep2 = newnode(); |
615 |
ep2->type = nextc; |
616 |
scan(); |
617 |
addekid(ep2, ep1); |
618 |
addekid(ep2, getE3()); |
619 |
if (esupport&E_RCONST) { |
620 |
EPNODE *ep3 = ep1->sibling; |
621 |
if (ep1->type == NUM && ep3->type == NUM) { |
622 |
ep2 = rconst(ep2); |
623 |
} else if (ep3->type == NUM) { |
624 |
if (ep2->type == '/') { |
625 |
if (ep3->v.num == 0) |
626 |
syntax("divide by zero constant"); |
627 |
ep2->type = '*'; /* for speed */ |
628 |
ep3->v.num = 1./ep3->v.num; |
629 |
} else if (ep3->v.num == 0) { |
630 |
ep1->sibling = NULL; /* (E2 * 0) */ |
631 |
epfree(ep2); |
632 |
ep2 = ep3; |
633 |
} |
634 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
635 |
epfree(ep3); /* (0 * E3) or (0 / E3) */ |
636 |
ep1->sibling = NULL; |
637 |
efree((char *)ep2); |
638 |
ep2 = ep1; |
639 |
} |
640 |
} |
641 |
ep1 = ep2; |
642 |
} |
643 |
return(ep1); |
644 |
} |
645 |
|
646 |
|
647 |
EPNODE * |
648 |
getE3(void) /* E3 -> E4 ^ E3 */ |
649 |
/* E4 */ |
650 |
{ |
651 |
register EPNODE *ep1, *ep2; |
652 |
|
653 |
ep1 = getE4(); |
654 |
if (nextc != '^') |
655 |
return(ep1); |
656 |
ep2 = newnode(); |
657 |
ep2->type = nextc; |
658 |
scan(); |
659 |
addekid(ep2, ep1); |
660 |
addekid(ep2, getE3()); |
661 |
if (esupport&E_RCONST) { |
662 |
EPNODE *ep3 = ep1->sibling; |
663 |
if (ep1->type == NUM && ep3->type == NUM) { |
664 |
ep2 = rconst(ep2); |
665 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
666 |
epfree(ep3); /* (0 ^ E3) */ |
667 |
ep1->sibling = NULL; |
668 |
efree((char *)ep2); |
669 |
ep2 = ep1; |
670 |
} else if ((ep3->type == NUM && ep3->v.num == 0) || |
671 |
(ep1->type == NUM && ep1->v.num == 1)) { |
672 |
epfree(ep2); /* (E4 ^ 0) or (1 ^ E3) */ |
673 |
ep2 = newnode(); |
674 |
ep2->type = NUM; |
675 |
ep2->v.num = 1; |
676 |
} |
677 |
} |
678 |
return(ep2); |
679 |
} |
680 |
|
681 |
|
682 |
EPNODE * |
683 |
getE4(void) /* E4 -> ADDOP E5 */ |
684 |
/* E5 */ |
685 |
{ |
686 |
register EPNODE *ep1, *ep2; |
687 |
|
688 |
if (nextc == '-') { |
689 |
scan(); |
690 |
ep2 = getE5(); |
691 |
if (ep2->type == NUM) { |
692 |
ep2->v.num = -ep2->v.num; |
693 |
return(ep2); |
694 |
} |
695 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
696 |
ep1 = ep2->v.kid; |
697 |
efree((char *)ep2); |
698 |
return(ep1); |
699 |
} |
700 |
ep1 = newnode(); |
701 |
ep1->type = UMINUS; |
702 |
addekid(ep1, ep2); |
703 |
return(ep1); |
704 |
} |
705 |
if (nextc == '+') |
706 |
scan(); |
707 |
return(getE5()); |
708 |
} |
709 |
|
710 |
|
711 |
EPNODE * |
712 |
getE5(void) /* E5 -> (E1) */ |
713 |
/* VAR */ |
714 |
/* NUM */ |
715 |
/* $N */ |
716 |
/* FUNC(E1,..) */ |
717 |
/* ARG */ |
718 |
{ |
719 |
int i; |
720 |
char *nam; |
721 |
register EPNODE *ep1, *ep2; |
722 |
|
723 |
if (nextc == '(') { |
724 |
scan(); |
725 |
ep1 = getE1(); |
726 |
if (nextc != ')') |
727 |
syntax("')' expected"); |
728 |
scan(); |
729 |
return(ep1); |
730 |
} |
731 |
|
732 |
if (esupport&E_INCHAN && nextc == '$') { |
733 |
scan(); |
734 |
ep1 = newnode(); |
735 |
ep1->type = CHAN; |
736 |
ep1->v.chan = getinum(); |
737 |
return(ep1); |
738 |
} |
739 |
|
740 |
if (esupport&(E_VARIABLE|E_FUNCTION) && |
741 |
(isalpha(nextc) || nextc == CNTXMARK)) { |
742 |
nam = getname(); |
743 |
ep1 = NULL; |
744 |
if ((esupport&(E_VARIABLE|E_FUNCTION)) == (E_VARIABLE|E_FUNCTION) |
745 |
&& curfunc != NULL) |
746 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
747 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
748 |
if (!strcmp(ep2->v.name, nam)) { |
749 |
ep1 = newnode(); |
750 |
ep1->type = ARG; |
751 |
ep1->v.chan = i; |
752 |
break; |
753 |
} |
754 |
if (ep1 == NULL) { |
755 |
ep1 = newnode(); |
756 |
ep1->type = VAR; |
757 |
ep1->v.ln = varinsert(nam); |
758 |
} |
759 |
if (esupport&E_FUNCTION && nextc == '(') { |
760 |
ep2 = newnode(); |
761 |
ep2->type = FUNC; |
762 |
addekid(ep2, ep1); |
763 |
ep1 = ep2; |
764 |
do { |
765 |
scan(); |
766 |
addekid(ep1, getE1()); |
767 |
} while (nextc == ','); |
768 |
if (nextc != ')') |
769 |
syntax("')' expected"); |
770 |
scan(); |
771 |
} else if (!(esupport&E_VARIABLE)) |
772 |
syntax("'(' expected"); |
773 |
if (esupport&E_RCONST && isconstvar(ep1)) |
774 |
ep1 = rconst(ep1); |
775 |
return(ep1); |
776 |
} |
777 |
|
778 |
if (isdecimal(nextc)) { |
779 |
ep1 = newnode(); |
780 |
ep1->type = NUM; |
781 |
ep1->v.num = getnum(); |
782 |
return(ep1); |
783 |
} |
784 |
syntax("unexpected character"); |
785 |
return NULL; /* pro forma return */ |
786 |
} |
787 |
|
788 |
|
789 |
EPNODE * |
790 |
rconst( /* reduce a constant expression */ |
791 |
register EPNODE *epar |
792 |
) |
793 |
{ |
794 |
register EPNODE *ep; |
795 |
|
796 |
ep = newnode(); |
797 |
ep->type = NUM; |
798 |
errno = 0; |
799 |
ep->v.num = evalue(epar); |
800 |
if (errno == EDOM || errno == ERANGE) |
801 |
syntax("bad constant expression"); |
802 |
epfree(epar); |
803 |
|
804 |
return(ep); |
805 |
} |
806 |
|
807 |
|
808 |
int |
809 |
isconstvar( /* is ep linked to a constant expression? */ |
810 |
register EPNODE *ep |
811 |
) |
812 |
{ |
813 |
register EPNODE *ep1; |
814 |
|
815 |
if (esupport&E_FUNCTION && ep->type == FUNC) { |
816 |
if (!isconstfun(ep->v.kid)) |
817 |
return(0); |
818 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
819 |
if (ep1->type != NUM && !isconstfun(ep1)) |
820 |
return(0); |
821 |
return(1); |
822 |
} |
823 |
if (ep->type != VAR) |
824 |
return(0); |
825 |
ep1 = ep->v.ln->def; |
826 |
if (ep1 == NULL || ep1->type != ':') |
827 |
return(0); |
828 |
if (esupport&E_FUNCTION && ep1->v.kid->type != SYM) |
829 |
return(0); |
830 |
return(1); |
831 |
} |
832 |
|
833 |
|
834 |
int |
835 |
isconstfun( /* is ep linked to a constant function? */ |
836 |
register EPNODE *ep |
837 |
) |
838 |
{ |
839 |
register EPNODE *dp; |
840 |
register LIBR *lp; |
841 |
|
842 |
if (ep->type != VAR) |
843 |
return(0); |
844 |
if ((dp = ep->v.ln->def) != NULL) { |
845 |
if (dp->v.kid->type == FUNC) |
846 |
return(dp->type == ':'); |
847 |
else |
848 |
return(0); /* don't identify masked library functions */ |
849 |
} |
850 |
if ((lp = ep->v.ln->lib) != NULL) |
851 |
return(lp->atyp == ':'); |
852 |
return(0); |
853 |
} |