1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: calexpr.c,v 2.37 2019/03/04 18:16:18 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, |
63 |
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 |
int prev_support = esupport; |
109 |
EPNODE *ep; |
110 |
double rval; |
111 |
|
112 |
esupport &= ~E_RCONST; /* don't bother reducing constant expr */ |
113 |
ep = eparse(expr); |
114 |
esupport = prev_support; /* as you were */ |
115 |
rval = evalue(ep); |
116 |
epfree(ep); |
117 |
return(rval); |
118 |
} |
119 |
|
120 |
|
121 |
int |
122 |
epcmp( /* compare two expressions for equivalence */ |
123 |
EPNODE *ep1, |
124 |
EPNODE *ep2 |
125 |
) |
126 |
{ |
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double d; |
128 |
|
129 |
if (ep1->type != ep2->type) |
130 |
return(1); |
131 |
|
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switch (ep1->type) { |
133 |
|
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case VAR: |
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return(ep1->v.ln != ep2->v.ln); |
136 |
|
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case NUM: |
138 |
if (ep2->v.num == 0) |
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return(ep1->v.num != 0); |
140 |
d = ep1->v.num / ep2->v.num; |
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return((d > 1.000000000001) | (d < 0.999999999999)); |
142 |
|
143 |
case CHAN: |
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case ARG: |
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return(ep1->v.chan != ep2->v.chan); |
146 |
|
147 |
case '=': |
148 |
case ':': |
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return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
150 |
|
151 |
case CLKT: |
152 |
case SYM: /* should never get this one */ |
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return(0); |
154 |
|
155 |
default: |
156 |
ep1 = ep1->v.kid; |
157 |
ep2 = ep2->v.kid; |
158 |
while (ep1 != NULL) { |
159 |
if (ep2 == NULL) |
160 |
return(1); |
161 |
if (epcmp(ep1, ep2)) |
162 |
return(1); |
163 |
ep1 = ep1->sibling; |
164 |
ep2 = ep2->sibling; |
165 |
} |
166 |
return(ep2 != NULL); |
167 |
} |
168 |
} |
169 |
|
170 |
|
171 |
void |
172 |
epfree( /* free a parse tree */ |
173 |
EPNODE *epar |
174 |
) |
175 |
{ |
176 |
EPNODE *ep; |
177 |
|
178 |
switch (epar->type) { |
179 |
|
180 |
case VAR: |
181 |
varfree(epar->v.ln); |
182 |
break; |
183 |
|
184 |
case SYM: |
185 |
freestr(epar->v.name); |
186 |
break; |
187 |
|
188 |
case NUM: |
189 |
case CHAN: |
190 |
case ARG: |
191 |
case CLKT: |
192 |
break; |
193 |
|
194 |
default: |
195 |
while ((ep = epar->v.kid) != NULL) { |
196 |
epar->v.kid = ep->sibling; |
197 |
epfree(ep); |
198 |
} |
199 |
break; |
200 |
|
201 |
} |
202 |
|
203 |
efree((char *)epar); |
204 |
} |
205 |
|
206 |
/* the following used to be a switch */ |
207 |
static double |
208 |
eargument( |
209 |
EPNODE *ep |
210 |
) |
211 |
{ |
212 |
return(argument(ep->v.chan)); |
213 |
} |
214 |
|
215 |
static double |
216 |
enumber( |
217 |
EPNODE *ep |
218 |
) |
219 |
{ |
220 |
return(ep->v.num); |
221 |
} |
222 |
|
223 |
static double |
224 |
euminus( |
225 |
EPNODE *ep |
226 |
) |
227 |
{ |
228 |
EPNODE *ep1 = ep->v.kid; |
229 |
|
230 |
return(-evalue(ep1)); |
231 |
} |
232 |
|
233 |
static double |
234 |
echannel( |
235 |
EPNODE *ep |
236 |
) |
237 |
{ |
238 |
return(chanvalue(ep->v.chan)); |
239 |
} |
240 |
|
241 |
static double |
242 |
eadd( |
243 |
EPNODE *ep |
244 |
) |
245 |
{ |
246 |
EPNODE *ep1 = ep->v.kid; |
247 |
|
248 |
return(evalue(ep1) + evalue(ep1->sibling)); |
249 |
} |
250 |
|
251 |
static double |
252 |
esubtr( |
253 |
EPNODE *ep |
254 |
) |
255 |
{ |
256 |
EPNODE *ep1 = ep->v.kid; |
257 |
|
258 |
return(evalue(ep1) - evalue(ep1->sibling)); |
259 |
} |
260 |
|
261 |
static double |
262 |
emult( |
263 |
EPNODE *ep |
264 |
) |
265 |
{ |
266 |
EPNODE *ep1 = ep->v.kid; |
267 |
|
268 |
return(evalue(ep1) * evalue(ep1->sibling)); |
269 |
} |
270 |
|
271 |
static double |
272 |
edivi( |
273 |
EPNODE *ep |
274 |
) |
275 |
{ |
276 |
EPNODE *ep1 = ep->v.kid; |
277 |
double d; |
278 |
|
279 |
d = evalue(ep1->sibling); |
280 |
if (d == 0.0) { |
281 |
wputs("Division by zero\n"); |
282 |
errno = ERANGE; |
283 |
return(0.0); |
284 |
} |
285 |
return(evalue(ep1) / d); |
286 |
} |
287 |
|
288 |
static double |
289 |
epow( |
290 |
EPNODE *ep |
291 |
) |
292 |
{ |
293 |
EPNODE *ep1 = ep->v.kid; |
294 |
double d; |
295 |
int lasterrno; |
296 |
|
297 |
lasterrno = errno; |
298 |
errno = 0; |
299 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
300 |
#ifdef isnan |
301 |
if (errno == 0) { |
302 |
if (isnan(d)) |
303 |
errno = EDOM; |
304 |
else if (isinf(d)) |
305 |
errno = ERANGE; |
306 |
} |
307 |
#endif |
308 |
if (errno == EDOM || errno == ERANGE) { |
309 |
wputs("Illegal power\n"); |
310 |
return(0.0); |
311 |
} |
312 |
errno = lasterrno; |
313 |
return(d); |
314 |
} |
315 |
|
316 |
static double |
317 |
ebotch( |
318 |
EPNODE *ep |
319 |
) |
320 |
{ |
321 |
eputs("Bad expression!\n"); |
322 |
quit(1); |
323 |
return 0.0; /* pro forma return */ |
324 |
} |
325 |
|
326 |
|
327 |
EPNODE * |
328 |
ekid( /* return pointer to a node's nth kid */ |
329 |
EPNODE *ep, |
330 |
int n |
331 |
) |
332 |
{ |
333 |
|
334 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
335 |
if (--n < 0) |
336 |
break; |
337 |
|
338 |
return(ep); |
339 |
} |
340 |
|
341 |
|
342 |
int |
343 |
nekids( /* return # of kids for node ep */ |
344 |
EPNODE *ep |
345 |
) |
346 |
{ |
347 |
int n = 0; |
348 |
|
349 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
350 |
n++; |
351 |
|
352 |
return(n); |
353 |
} |
354 |
|
355 |
|
356 |
void |
357 |
initfile( /* prepare input file */ |
358 |
FILE *fp, |
359 |
char *fn, |
360 |
int ln |
361 |
) |
362 |
{ |
363 |
static char inpbuf[MAXLINE]; |
364 |
|
365 |
infp = fp; |
366 |
linbuf = inpbuf; |
367 |
infile = fn; |
368 |
lineno = ln; |
369 |
linepos = 0; |
370 |
inpbuf[0] = '\0'; |
371 |
scan(); |
372 |
} |
373 |
|
374 |
|
375 |
void |
376 |
initstr( /* prepare input string */ |
377 |
char *s, |
378 |
char *fn, |
379 |
int ln |
380 |
) |
381 |
{ |
382 |
infp = NULL; |
383 |
infile = fn; |
384 |
lineno = ln; |
385 |
linbuf = s; |
386 |
linepos = 0; |
387 |
scan(); |
388 |
} |
389 |
|
390 |
|
391 |
void |
392 |
getscanpos( /* return current scan position */ |
393 |
char **fnp, |
394 |
int *lnp, |
395 |
char **spp, |
396 |
FILE **fpp |
397 |
) |
398 |
{ |
399 |
if (fnp != NULL) *fnp = infile; |
400 |
if (lnp != NULL) *lnp = lineno; |
401 |
if (spp != NULL) *spp = linbuf+linepos; |
402 |
if (fpp != NULL) *fpp = infp; |
403 |
} |
404 |
|
405 |
|
406 |
int |
407 |
scan(void) /* scan next character, return literal next */ |
408 |
{ |
409 |
int lnext = 0; |
410 |
|
411 |
do { |
412 |
if (linbuf[linepos] == '\0') |
413 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
414 |
nextc = EOF; |
415 |
else { |
416 |
nextc = linbuf[0]; |
417 |
lineno++; |
418 |
linepos = 1; |
419 |
} |
420 |
else |
421 |
nextc = linbuf[linepos++]; |
422 |
if (!lnext) |
423 |
lnext = nextc; |
424 |
if (nextc == eofc) { |
425 |
nextc = EOF; |
426 |
break; |
427 |
} |
428 |
if (nextc == '{') { |
429 |
scan(); |
430 |
while (nextc != '}') |
431 |
if (nextc == EOF) |
432 |
syntax("'}' expected"); |
433 |
else |
434 |
scan(); |
435 |
scan(); |
436 |
} |
437 |
} while (isspace(nextc)); |
438 |
return(lnext); |
439 |
} |
440 |
|
441 |
|
442 |
char * |
443 |
long2ascii( /* convert long to ascii */ |
444 |
long l |
445 |
) |
446 |
{ |
447 |
static char buf[16]; |
448 |
char *cp; |
449 |
int neg = 0; |
450 |
|
451 |
if (l == 0) |
452 |
return("0"); |
453 |
if (l < 0) { |
454 |
l = -l; |
455 |
neg++; |
456 |
} |
457 |
cp = buf + sizeof(buf); |
458 |
*--cp = '\0'; |
459 |
while (l) { |
460 |
*--cp = l % 10 + '0'; |
461 |
l /= 10; |
462 |
} |
463 |
if (neg) |
464 |
*--cp = '-'; |
465 |
return(cp); |
466 |
} |
467 |
|
468 |
|
469 |
void |
470 |
syntax( /* report syntax error and quit */ |
471 |
char *err |
472 |
) |
473 |
{ |
474 |
int i; |
475 |
|
476 |
if (infile != NULL || lineno != 0) { |
477 |
if (infile != NULL) eputs(infile); |
478 |
if (lineno != 0) { |
479 |
eputs(infile != NULL ? ", line " : "line "); |
480 |
eputs(long2ascii((long)lineno)); |
481 |
} |
482 |
eputs(":\n"); |
483 |
} |
484 |
eputs(linbuf); |
485 |
if (linbuf[strlen(linbuf)-1] != '\n') |
486 |
eputs("\n"); |
487 |
for (i = 0; i < linepos-1; i++) |
488 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
489 |
eputs("^ "); |
490 |
eputs(err); |
491 |
eputs("\n"); |
492 |
quit(1); |
493 |
} |
494 |
|
495 |
|
496 |
void |
497 |
addekid( /* add a child to ep */ |
498 |
EPNODE *ep, |
499 |
EPNODE *ekid |
500 |
) |
501 |
{ |
502 |
if (ep->v.kid == NULL) |
503 |
ep->v.kid = ekid; |
504 |
else { |
505 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
506 |
; |
507 |
ep->sibling = ekid; |
508 |
} |
509 |
ekid->sibling = NULL; |
510 |
} |
511 |
|
512 |
|
513 |
char * |
514 |
getname(void) /* scan an identifier */ |
515 |
{ |
516 |
static char str[RMAXWORD+1]; |
517 |
int i, lnext; |
518 |
|
519 |
lnext = nextc; |
520 |
for (i = 0; i < RMAXWORD && isid(lnext); i++, lnext = scan()) |
521 |
str[i] = lnext; |
522 |
str[i] = '\0'; |
523 |
while (isid(lnext)) /* skip rest of name */ |
524 |
lnext = scan(); |
525 |
|
526 |
return(str); |
527 |
} |
528 |
|
529 |
|
530 |
int |
531 |
getinum(void) /* scan a positive integer */ |
532 |
{ |
533 |
int n, lnext; |
534 |
|
535 |
n = 0; |
536 |
lnext = nextc; |
537 |
while (isdigit(lnext)) { |
538 |
n = n * 10 + lnext - '0'; |
539 |
lnext = scan(); |
540 |
} |
541 |
return(n); |
542 |
} |
543 |
|
544 |
|
545 |
double |
546 |
getnum(void) /* scan a positive float */ |
547 |
{ |
548 |
int i, lnext; |
549 |
char str[RMAXWORD+1]; |
550 |
|
551 |
i = 0; |
552 |
lnext = nextc; |
553 |
while (isdigit(lnext) && i < RMAXWORD) { |
554 |
str[i++] = lnext; |
555 |
lnext = scan(); |
556 |
} |
557 |
if (lnext == '.' && i < RMAXWORD) { |
558 |
str[i++] = lnext; |
559 |
lnext = scan(); |
560 |
if (i == 1 && !isdigit(lnext)) |
561 |
syntax("badly formed number"); |
562 |
while (isdigit(lnext) && i < RMAXWORD) { |
563 |
str[i++] = lnext; |
564 |
lnext = scan(); |
565 |
} |
566 |
} |
567 |
if ((lnext == 'e') | (lnext == 'E') && i < RMAXWORD) { |
568 |
str[i++] = lnext; |
569 |
lnext = scan(); |
570 |
if ((lnext == '-') | (lnext == '+') && i < RMAXWORD) { |
571 |
str[i++] = lnext; |
572 |
lnext = scan(); |
573 |
} |
574 |
if (!isdigit(lnext)) |
575 |
syntax("missing exponent"); |
576 |
while (isdigit(lnext) && i < RMAXWORD) { |
577 |
str[i++] = lnext; |
578 |
lnext = scan(); |
579 |
} |
580 |
} |
581 |
str[i] = '\0'; |
582 |
|
583 |
return(atof(str)); |
584 |
} |
585 |
|
586 |
|
587 |
EPNODE * |
588 |
getE1(void) /* E1 -> E1 ADDOP E2 */ |
589 |
/* E2 */ |
590 |
{ |
591 |
EPNODE *ep1, *ep2; |
592 |
|
593 |
ep1 = getE2(); |
594 |
while (nextc == '+' || nextc == '-') { |
595 |
ep2 = newnode(); |
596 |
ep2->type = nextc; |
597 |
scan(); |
598 |
addekid(ep2, ep1); |
599 |
addekid(ep2, getE2()); |
600 |
if (esupport&E_RCONST && |
601 |
ep1->type == NUM && ep1->sibling->type == NUM) |
602 |
ep2 = rconst(ep2); |
603 |
ep1 = ep2; |
604 |
} |
605 |
return(ep1); |
606 |
} |
607 |
|
608 |
|
609 |
EPNODE * |
610 |
getE2(void) /* E2 -> E2 MULOP E3 */ |
611 |
/* E3 */ |
612 |
{ |
613 |
EPNODE *ep1, *ep2; |
614 |
|
615 |
ep1 = getE3(); |
616 |
while (nextc == '*' || nextc == '/') { |
617 |
ep2 = newnode(); |
618 |
ep2->type = nextc; |
619 |
scan(); |
620 |
addekid(ep2, ep1); |
621 |
addekid(ep2, getE3()); |
622 |
if (esupport&E_RCONST) { |
623 |
EPNODE *ep3 = ep1->sibling; |
624 |
if (ep1->type == NUM && ep3->type == NUM) { |
625 |
ep2 = rconst(ep2); |
626 |
} else if (ep3->type == NUM) { |
627 |
if (ep2->type == '/') { |
628 |
if (ep3->v.num == 0) |
629 |
syntax("divide by zero constant"); |
630 |
ep2->type = '*'; /* for speed */ |
631 |
ep3->v.num = 1./ep3->v.num; |
632 |
} else if (ep3->v.num == 0) { |
633 |
ep1->sibling = NULL; /* (E2 * 0) */ |
634 |
epfree(ep2); |
635 |
ep2 = ep3; |
636 |
} |
637 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
638 |
epfree(ep3); /* (0 * E3) or (0 / E3) */ |
639 |
ep1->sibling = NULL; |
640 |
efree((char *)ep2); |
641 |
ep2 = ep1; |
642 |
} |
643 |
} |
644 |
ep1 = ep2; |
645 |
} |
646 |
return(ep1); |
647 |
} |
648 |
|
649 |
|
650 |
EPNODE * |
651 |
getE3(void) /* E3 -> E4 ^ E3 */ |
652 |
/* E4 */ |
653 |
{ |
654 |
EPNODE *ep1, *ep2; |
655 |
|
656 |
ep1 = getE4(); |
657 |
if (nextc != '^') |
658 |
return(ep1); |
659 |
ep2 = newnode(); |
660 |
ep2->type = nextc; |
661 |
scan(); |
662 |
addekid(ep2, ep1); |
663 |
addekid(ep2, getE3()); |
664 |
if (esupport&E_RCONST) { |
665 |
EPNODE *ep3 = ep1->sibling; |
666 |
if (ep1->type == NUM && ep3->type == NUM) { |
667 |
ep2 = rconst(ep2); |
668 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
669 |
epfree(ep3); /* (0 ^ E3) */ |
670 |
ep1->sibling = NULL; |
671 |
efree((char *)ep2); |
672 |
ep2 = ep1; |
673 |
} else if ((ep3->type == NUM && ep3->v.num == 0) || |
674 |
(ep1->type == NUM && ep1->v.num == 1)) { |
675 |
epfree(ep2); /* (E4 ^ 0) or (1 ^ E3) */ |
676 |
ep2 = newnode(); |
677 |
ep2->type = NUM; |
678 |
ep2->v.num = 1; |
679 |
} |
680 |
} |
681 |
return(ep2); |
682 |
} |
683 |
|
684 |
|
685 |
EPNODE * |
686 |
getE4(void) /* E4 -> ADDOP E5 */ |
687 |
/* E5 */ |
688 |
{ |
689 |
EPNODE *ep1, *ep2; |
690 |
|
691 |
if (nextc == '-') { |
692 |
scan(); |
693 |
ep2 = getE5(); |
694 |
if (ep2->type == NUM) { |
695 |
ep2->v.num = -ep2->v.num; |
696 |
return(ep2); |
697 |
} |
698 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
699 |
ep1 = ep2->v.kid; |
700 |
efree((char *)ep2); |
701 |
return(ep1); |
702 |
} |
703 |
ep1 = newnode(); |
704 |
ep1->type = UMINUS; |
705 |
addekid(ep1, ep2); |
706 |
return(ep1); |
707 |
} |
708 |
if (nextc == '+') |
709 |
scan(); |
710 |
return(getE5()); |
711 |
} |
712 |
|
713 |
|
714 |
EPNODE * |
715 |
getE5(void) /* E5 -> (E1) */ |
716 |
/* VAR */ |
717 |
/* NUM */ |
718 |
/* $N */ |
719 |
/* FUNC(E1,..) */ |
720 |
/* ARG */ |
721 |
{ |
722 |
int i; |
723 |
char *nam; |
724 |
EPNODE *ep1, *ep2; |
725 |
|
726 |
if (nextc == '(') { |
727 |
scan(); |
728 |
ep1 = getE1(); |
729 |
if (nextc != ')') |
730 |
syntax("')' expected"); |
731 |
scan(); |
732 |
return(ep1); |
733 |
} |
734 |
|
735 |
if (esupport&E_INCHAN && nextc == '$') { |
736 |
scan(); |
737 |
ep1 = newnode(); |
738 |
ep1->type = CHAN; |
739 |
ep1->v.chan = getinum(); |
740 |
return(ep1); |
741 |
} |
742 |
|
743 |
if (esupport&(E_VARIABLE|E_FUNCTION) && |
744 |
(isalpha(nextc) || nextc == CNTXMARK)) { |
745 |
nam = getname(); |
746 |
ep1 = NULL; |
747 |
if ((esupport&(E_VARIABLE|E_FUNCTION)) == (E_VARIABLE|E_FUNCTION) |
748 |
&& curfunc != NULL) |
749 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
750 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
751 |
if (!strcmp(ep2->v.name, nam)) { |
752 |
ep1 = newnode(); |
753 |
ep1->type = ARG; |
754 |
ep1->v.chan = i; |
755 |
break; |
756 |
} |
757 |
if (ep1 == NULL) { |
758 |
ep1 = newnode(); |
759 |
ep1->type = VAR; |
760 |
ep1->v.ln = varinsert(nam); |
761 |
} |
762 |
if (esupport&E_FUNCTION && nextc == '(') { |
763 |
ep2 = newnode(); |
764 |
ep2->type = FUNC; |
765 |
addekid(ep2, ep1); |
766 |
ep1 = ep2; |
767 |
do { |
768 |
scan(); |
769 |
addekid(ep1, getE1()); |
770 |
} while (nextc == ','); |
771 |
if (nextc != ')') |
772 |
syntax("')' expected"); |
773 |
scan(); |
774 |
} else if (!(esupport&E_VARIABLE)) |
775 |
syntax("'(' expected"); |
776 |
if (esupport&E_RCONST && isconstvar(ep1)) |
777 |
ep1 = rconst(ep1); |
778 |
return(ep1); |
779 |
} |
780 |
|
781 |
if (isdecimal(nextc)) { |
782 |
ep1 = newnode(); |
783 |
ep1->type = NUM; |
784 |
ep1->v.num = getnum(); |
785 |
return(ep1); |
786 |
} |
787 |
syntax("unexpected character"); |
788 |
return NULL; /* pro forma return */ |
789 |
} |
790 |
|
791 |
|
792 |
EPNODE * |
793 |
rconst( /* reduce a constant expression */ |
794 |
EPNODE *epar |
795 |
) |
796 |
{ |
797 |
EPNODE *ep; |
798 |
|
799 |
ep = newnode(); |
800 |
ep->type = NUM; |
801 |
errno = 0; |
802 |
ep->v.num = evalue(epar); |
803 |
if (errno == EDOM || errno == ERANGE) |
804 |
syntax("bad constant expression"); |
805 |
epfree(epar); |
806 |
|
807 |
return(ep); |
808 |
} |
809 |
|
810 |
|
811 |
int |
812 |
isconstvar( /* is ep linked to a constant expression? */ |
813 |
EPNODE *ep |
814 |
) |
815 |
{ |
816 |
EPNODE *ep1; |
817 |
|
818 |
if (esupport&E_FUNCTION && ep->type == FUNC) { |
819 |
if (!isconstfun(ep->v.kid)) |
820 |
return(0); |
821 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
822 |
if (ep1->type != NUM && !isconstfun(ep1)) |
823 |
return(0); |
824 |
return(1); |
825 |
} |
826 |
if (ep->type != VAR) |
827 |
return(0); |
828 |
ep1 = ep->v.ln->def; |
829 |
if (ep1 == NULL || ep1->type != ':') |
830 |
return(0); |
831 |
if (esupport&E_FUNCTION && ep1->v.kid->type != SYM) |
832 |
return(0); |
833 |
return(1); |
834 |
} |
835 |
|
836 |
|
837 |
int |
838 |
isconstfun( /* is ep linked to a constant function? */ |
839 |
EPNODE *ep |
840 |
) |
841 |
{ |
842 |
EPNODE *dp; |
843 |
LIBR *lp; |
844 |
|
845 |
if (ep->type != VAR) |
846 |
return(0); |
847 |
if ((dp = ep->v.ln->def) != NULL) { |
848 |
if (dp->v.kid->type == FUNC) |
849 |
return(dp->type == ':'); |
850 |
else |
851 |
return(0); /* don't identify masked library functions */ |
852 |
} |
853 |
if ((lp = ep->v.ln->lib) != NULL) |
854 |
return(lp->atyp == ':'); |
855 |
return(0); |
856 |
} |