1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: calexpr.c,v 2.42 2022/04/08 23:32:25 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 |
* |
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* 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, |
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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, |
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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,1); |
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) |
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return(1); |
129 |
|
130 |
switch (ep1->type) { |
131 |
|
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case VAR: |
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return(ep1->v.ln != ep2->v.ln); |
134 |
|
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case NUM: |
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if (ep2->v.num == 0) |
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return(ep1->v.num != 0); |
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d = ep1->v.num / ep2->v.num; |
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return((d > 1.000000000001) | (d < 0.999999999999)); |
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|
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case CHAN: |
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case ARG: |
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return(ep1->v.chan != ep2->v.chan); |
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|
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case '=': |
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case ':': |
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return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
148 |
|
149 |
case CLKT: |
150 |
case SYM: /* should never get this one */ |
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return(0); |
152 |
|
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default: |
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ep1 = ep1->v.kid; |
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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 |
int frep |
173 |
) |
174 |
{ |
175 |
EPNODE *ep; |
176 |
|
177 |
switch (epar->type) { |
178 |
|
179 |
case VAR: |
180 |
varfree(epar->v.ln); |
181 |
break; |
182 |
|
183 |
case SYM: |
184 |
freestr(epar->v.name); |
185 |
break; |
186 |
|
187 |
case NUM: |
188 |
case CHAN: |
189 |
case ARG: |
190 |
case CLKT: |
191 |
break; |
192 |
|
193 |
default: |
194 |
if (epar->nkids < 0) { |
195 |
ep = epar->v.kid - epar->nkids; |
196 |
while (ep > epar->v.kid) |
197 |
epfree(--ep, 0); |
198 |
efree(ep); /* free array space */ |
199 |
} else |
200 |
while ((ep = epar->v.kid) != NULL) { |
201 |
epar->v.kid = ep->sibling; |
202 |
epfree(ep, 1); |
203 |
} |
204 |
break; |
205 |
|
206 |
} |
207 |
if (frep) |
208 |
efree(epar); |
209 |
} |
210 |
|
211 |
|
212 |
void |
213 |
epoptimize( /* realloc lists as arrays if > length 3 */ |
214 |
EPNODE *epar |
215 |
) |
216 |
{ |
217 |
EPNODE *ep; |
218 |
|
219 |
if (epar->nkids > 3) { /* do this node if > 3 kids */ |
220 |
int n = 1; |
221 |
epar->v.kid = (EPNODE *)erealloc(epar->v.kid, |
222 |
sizeof(EPNODE)*epar->nkids); |
223 |
while (n < epar->nkids) { |
224 |
ep = epar->v.kid[n-1].sibling; |
225 |
epar->v.kid[n] = *ep; |
226 |
efree(ep); /* not epfree()! */ |
227 |
epar->v.kid[n-1].sibling = epar->v.kid + n; |
228 |
n++; |
229 |
} |
230 |
epar->nkids = -epar->nkids; |
231 |
} |
232 |
if (epar->nkids) /* do children if any */ |
233 |
for (ep = epar->v.kid; ep != NULL; ep = ep->sibling) |
234 |
epoptimize(ep); |
235 |
} |
236 |
|
237 |
/* the following used to be a switch */ |
238 |
static double |
239 |
eargument( |
240 |
EPNODE *ep |
241 |
) |
242 |
{ |
243 |
return(argument(ep->v.chan)); |
244 |
} |
245 |
|
246 |
static double |
247 |
enumber( |
248 |
EPNODE *ep |
249 |
) |
250 |
{ |
251 |
return(ep->v.num); |
252 |
} |
253 |
|
254 |
static double |
255 |
euminus( |
256 |
EPNODE *ep |
257 |
) |
258 |
{ |
259 |
EPNODE *ep1 = ep->v.kid; |
260 |
|
261 |
return(-evalue(ep1)); |
262 |
} |
263 |
|
264 |
static double |
265 |
echannel( |
266 |
EPNODE *ep |
267 |
) |
268 |
{ |
269 |
return(chanvalue(ep->v.chan)); |
270 |
} |
271 |
|
272 |
static double |
273 |
eadd( |
274 |
EPNODE *ep |
275 |
) |
276 |
{ |
277 |
EPNODE *ep1 = ep->v.kid; |
278 |
|
279 |
return(evalue(ep1) + evalue(ep1->sibling)); |
280 |
} |
281 |
|
282 |
static double |
283 |
esubtr( |
284 |
EPNODE *ep |
285 |
) |
286 |
{ |
287 |
EPNODE *ep1 = ep->v.kid; |
288 |
|
289 |
return(evalue(ep1) - evalue(ep1->sibling)); |
290 |
} |
291 |
|
292 |
static double |
293 |
emult( |
294 |
EPNODE *ep |
295 |
) |
296 |
{ |
297 |
EPNODE *ep1 = ep->v.kid; |
298 |
|
299 |
return(evalue(ep1) * evalue(ep1->sibling)); |
300 |
} |
301 |
|
302 |
static double |
303 |
edivi( |
304 |
EPNODE *ep |
305 |
) |
306 |
{ |
307 |
EPNODE *ep1 = ep->v.kid; |
308 |
double d; |
309 |
|
310 |
d = evalue(ep1->sibling); |
311 |
if (d == 0.0) { |
312 |
wputs("Division by zero\n"); |
313 |
errno = ERANGE; |
314 |
return(0.0); |
315 |
} |
316 |
return(evalue(ep1) / d); |
317 |
} |
318 |
|
319 |
static double |
320 |
epow( |
321 |
EPNODE *ep |
322 |
) |
323 |
{ |
324 |
EPNODE *ep1 = ep->v.kid; |
325 |
double d; |
326 |
int lasterrno; |
327 |
|
328 |
lasterrno = errno; |
329 |
errno = 0; |
330 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
331 |
#ifdef isnan |
332 |
if (errno == 0) { |
333 |
if (isnan(d)) |
334 |
errno = EDOM; |
335 |
else if (isinf(d)) |
336 |
errno = ERANGE; |
337 |
} |
338 |
#endif |
339 |
if ((errno == EDOM) | (errno == ERANGE)) { |
340 |
wputs("Illegal power\n"); |
341 |
return(0.0); |
342 |
} |
343 |
errno = lasterrno; |
344 |
return(d); |
345 |
} |
346 |
|
347 |
static double |
348 |
ebotch( |
349 |
EPNODE *ep |
350 |
) |
351 |
{ |
352 |
eputs("Bad expression!\n"); |
353 |
quit(1); |
354 |
return 0.0; /* pro forma return */ |
355 |
} |
356 |
|
357 |
|
358 |
EPNODE * |
359 |
ekid( /* return pointer to a node's nth kid */ |
360 |
EPNODE *ep, |
361 |
int n |
362 |
) |
363 |
{ |
364 |
if (ep->nkids < 0) { /* allocated array? */ |
365 |
if (n >= -ep->nkids) |
366 |
return(NULL); |
367 |
return(ep->v.kid + n); |
368 |
} |
369 |
ep = ep->v.kid; /* else get from list */ |
370 |
while (n-- > 0) |
371 |
if ((ep = ep->sibling) == NULL) |
372 |
break; |
373 |
return(ep); |
374 |
} |
375 |
|
376 |
|
377 |
void |
378 |
initfile( /* prepare input file */ |
379 |
FILE *fp, |
380 |
char *fn, |
381 |
int ln |
382 |
) |
383 |
{ |
384 |
static char inpbuf[MAXLINE]; |
385 |
|
386 |
infp = fp; |
387 |
linbuf = inpbuf; |
388 |
infile = fn; |
389 |
lineno = ln; |
390 |
linepos = 0; |
391 |
inpbuf[0] = '\0'; |
392 |
scan(); |
393 |
} |
394 |
|
395 |
|
396 |
void |
397 |
initstr( /* prepare input string */ |
398 |
char *s, |
399 |
char *fn, |
400 |
int ln |
401 |
) |
402 |
{ |
403 |
infp = NULL; |
404 |
infile = fn; |
405 |
lineno = ln; |
406 |
linbuf = s; |
407 |
linepos = 0; |
408 |
scan(); |
409 |
} |
410 |
|
411 |
|
412 |
void |
413 |
getscanpos( /* return current scan position */ |
414 |
char **fnp, |
415 |
int *lnp, |
416 |
char **spp, |
417 |
FILE **fpp |
418 |
) |
419 |
{ |
420 |
if (fnp != NULL) *fnp = infile; |
421 |
if (lnp != NULL) *lnp = lineno; |
422 |
if (spp != NULL) *spp = linbuf+linepos; |
423 |
if (fpp != NULL) *fpp = infp; |
424 |
} |
425 |
|
426 |
|
427 |
int |
428 |
scan(void) /* scan next character, return literal next */ |
429 |
{ |
430 |
int lnext = 0; |
431 |
|
432 |
do { |
433 |
if (linbuf[linepos] == '\0') |
434 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
435 |
nextc = EOF; |
436 |
else { |
437 |
nextc = linbuf[0]; |
438 |
lineno++; |
439 |
linepos = 1; |
440 |
} |
441 |
else |
442 |
nextc = linbuf[linepos++]; |
443 |
if (!lnext) |
444 |
lnext = nextc; |
445 |
if (nextc == eofc) { |
446 |
nextc = EOF; |
447 |
break; |
448 |
} |
449 |
if (nextc == '{') { |
450 |
scan(); |
451 |
while (nextc != '}') |
452 |
if (nextc == EOF) |
453 |
syntax("'}' expected"); |
454 |
else |
455 |
scan(); |
456 |
scan(); |
457 |
} |
458 |
} while (isspace(nextc)); |
459 |
return(lnext); |
460 |
} |
461 |
|
462 |
|
463 |
char * |
464 |
long2ascii( /* convert long to ascii */ |
465 |
long l |
466 |
) |
467 |
{ |
468 |
static char buf[16]; |
469 |
char *cp; |
470 |
int neg = 0; |
471 |
|
472 |
if (l == 0) |
473 |
return("0"); |
474 |
if (l < 0) { |
475 |
l = -l; |
476 |
neg++; |
477 |
} |
478 |
cp = buf + sizeof(buf); |
479 |
*--cp = '\0'; |
480 |
while (l) { |
481 |
*--cp = l % 10 + '0'; |
482 |
l /= 10; |
483 |
} |
484 |
if (neg) |
485 |
*--cp = '-'; |
486 |
return(cp); |
487 |
} |
488 |
|
489 |
|
490 |
void |
491 |
syntax( /* report syntax error and quit */ |
492 |
char *err |
493 |
) |
494 |
{ |
495 |
int i; |
496 |
|
497 |
if ((infile != NULL) | (lineno != 0)) { |
498 |
if (infile != NULL) eputs(infile); |
499 |
if (lineno != 0) { |
500 |
eputs(infile != NULL ? ", line " : "line "); |
501 |
eputs(long2ascii((long)lineno)); |
502 |
} |
503 |
eputs(":\n"); |
504 |
} |
505 |
eputs(linbuf); |
506 |
if (linbuf[strlen(linbuf)-1] != '\n') |
507 |
eputs("\n"); |
508 |
for (i = 0; i < linepos-1; i++) |
509 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
510 |
eputs("^ "); |
511 |
eputs(err); |
512 |
eputs("\n"); |
513 |
quit(1); |
514 |
} |
515 |
|
516 |
|
517 |
void |
518 |
addekid( /* add a child to ep */ |
519 |
EPNODE *ep, |
520 |
EPNODE *ek |
521 |
) |
522 |
{ |
523 |
if (ep->nkids < 0) { |
524 |
eputs("Cannot add child after optimization\n"); |
525 |
quit(1); |
526 |
} |
527 |
ep->nkids++; |
528 |
if (ep->v.kid == NULL) |
529 |
ep->v.kid = ek; |
530 |
else { |
531 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
532 |
; |
533 |
ep->sibling = ek; |
534 |
} |
535 |
ek->sibling = NULL; |
536 |
} |
537 |
|
538 |
|
539 |
char * |
540 |
getname(void) /* scan an identifier */ |
541 |
{ |
542 |
static char str[RMAXWORD+1]; |
543 |
int i, lnext; |
544 |
|
545 |
lnext = nextc; |
546 |
for (i = 0; i < RMAXWORD && isid(lnext); i++, lnext = scan()) |
547 |
str[i] = lnext; |
548 |
str[i] = '\0'; |
549 |
while (isid(lnext)) /* skip rest of name */ |
550 |
lnext = scan(); |
551 |
|
552 |
return(str); |
553 |
} |
554 |
|
555 |
|
556 |
int |
557 |
getinum(void) /* scan a positive integer */ |
558 |
{ |
559 |
int n, lnext; |
560 |
|
561 |
n = 0; |
562 |
lnext = nextc; |
563 |
while (isdigit(lnext)) { |
564 |
n = n * 10 + lnext - '0'; |
565 |
lnext = scan(); |
566 |
} |
567 |
return(n); |
568 |
} |
569 |
|
570 |
|
571 |
double |
572 |
getnum(void) /* scan a positive float */ |
573 |
{ |
574 |
int i, lnext; |
575 |
char str[RMAXWORD+1]; |
576 |
|
577 |
i = 0; |
578 |
lnext = nextc; |
579 |
while (isdigit(lnext) && i < RMAXWORD) { |
580 |
str[i++] = lnext; |
581 |
lnext = scan(); |
582 |
} |
583 |
if ((lnext == '.') & (i < RMAXWORD)) { |
584 |
str[i++] = lnext; |
585 |
lnext = scan(); |
586 |
if (i == 1 && !isdigit(lnext)) |
587 |
syntax("badly formed number"); |
588 |
while (isdigit(lnext) && i < RMAXWORD) { |
589 |
str[i++] = lnext; |
590 |
lnext = scan(); |
591 |
} |
592 |
} |
593 |
if ((lnext == 'e') | (lnext == 'E') && i < RMAXWORD) { |
594 |
str[i++] = lnext; |
595 |
lnext = scan(); |
596 |
if ((lnext == '-') | (lnext == '+') && i < RMAXWORD) { |
597 |
str[i++] = lnext; |
598 |
lnext = scan(); |
599 |
} |
600 |
if (!isdigit(lnext)) |
601 |
syntax("missing exponent"); |
602 |
while (isdigit(lnext) && i < RMAXWORD) { |
603 |
str[i++] = lnext; |
604 |
lnext = scan(); |
605 |
} |
606 |
} |
607 |
str[i] = '\0'; |
608 |
|
609 |
return(atof(str)); |
610 |
} |
611 |
|
612 |
|
613 |
EPNODE * |
614 |
getE1(void) /* E1 -> E1 ADDOP E2 */ |
615 |
/* E2 */ |
616 |
{ |
617 |
EPNODE *ep1, *ep2; |
618 |
|
619 |
ep1 = getE2(); |
620 |
while ((nextc == '+') | (nextc == '-')) { |
621 |
ep2 = newnode(); |
622 |
ep2->type = nextc; |
623 |
scan(); |
624 |
addekid(ep2, ep1); |
625 |
addekid(ep2, getE2()); |
626 |
if (esupport&E_RCONST && |
627 |
(ep1->type == NUM) & (ep1->sibling->type == NUM)) |
628 |
ep2 = rconst(ep2); |
629 |
ep1 = ep2; |
630 |
} |
631 |
return(ep1); |
632 |
} |
633 |
|
634 |
|
635 |
EPNODE * |
636 |
getE2(void) /* E2 -> E2 MULOP E3 */ |
637 |
/* E3 */ |
638 |
{ |
639 |
EPNODE *ep1, *ep2; |
640 |
|
641 |
ep1 = getE3(); |
642 |
while ((nextc == '*') | (nextc == '/')) { |
643 |
ep2 = newnode(); |
644 |
ep2->type = nextc; |
645 |
scan(); |
646 |
addekid(ep2, ep1); |
647 |
addekid(ep2, getE3()); |
648 |
if (esupport&E_RCONST) { |
649 |
EPNODE *ep3 = ep1->sibling; |
650 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
651 |
ep2 = rconst(ep2); |
652 |
} else if (ep3->type == NUM) { |
653 |
if (ep2->type == '/') { |
654 |
if (ep3->v.num == 0) |
655 |
syntax("divide by zero constant"); |
656 |
ep2->type = '*'; /* for speed */ |
657 |
ep3->v.num = 1./ep3->v.num; |
658 |
} else if (ep3->v.num == 0) { |
659 |
ep1->sibling = NULL; /* (E2 * 0) */ |
660 |
epfree(ep2,1); |
661 |
ep2 = ep3; |
662 |
} |
663 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
664 |
epfree(ep3,1); /* (0 * E3) or (0 / E3) */ |
665 |
ep1->sibling = NULL; |
666 |
efree(ep2); |
667 |
ep2 = ep1; |
668 |
} |
669 |
} |
670 |
ep1 = ep2; |
671 |
} |
672 |
return(ep1); |
673 |
} |
674 |
|
675 |
|
676 |
EPNODE * |
677 |
getE3(void) /* E3 -> E4 ^ E3 */ |
678 |
/* E4 */ |
679 |
{ |
680 |
EPNODE *ep1, *ep2; |
681 |
|
682 |
ep1 = getE4(); |
683 |
if (nextc != '^') |
684 |
return(ep1); |
685 |
ep2 = newnode(); |
686 |
ep2->type = nextc; |
687 |
scan(); |
688 |
addekid(ep2, ep1); |
689 |
addekid(ep2, getE3()); |
690 |
if (esupport&E_RCONST) { |
691 |
EPNODE *ep3 = ep1->sibling; |
692 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
693 |
ep2 = rconst(ep2); |
694 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
695 |
epfree(ep3,1); /* (0 ^ E3) */ |
696 |
ep1->sibling = NULL; |
697 |
efree(ep2); |
698 |
ep2 = ep1; |
699 |
} else if ((ep3->type == NUM && ep3->v.num == 0) | |
700 |
(ep1->type == NUM && ep1->v.num == 1)) { |
701 |
epfree(ep2,1); /* (E4 ^ 0) or (1 ^ E3) */ |
702 |
ep2 = newnode(); |
703 |
ep2->type = NUM; |
704 |
ep2->v.num = 1; |
705 |
} else if (ep3->type == NUM && ep3->v.num == 1) { |
706 |
efree(ep3); /* (E4 ^ 1) */ |
707 |
ep1->sibling = NULL; |
708 |
efree(ep2); |
709 |
ep2 = ep1; |
710 |
} |
711 |
} |
712 |
return(ep2); |
713 |
} |
714 |
|
715 |
|
716 |
EPNODE * |
717 |
getE4(void) /* E4 -> ADDOP E5 */ |
718 |
/* E5 */ |
719 |
{ |
720 |
EPNODE *ep1, *ep2; |
721 |
|
722 |
if (nextc == '-') { |
723 |
scan(); |
724 |
ep2 = getE5(); |
725 |
if (ep2->type == NUM) { |
726 |
ep2->v.num = -ep2->v.num; |
727 |
return(ep2); |
728 |
} |
729 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
730 |
ep1 = ep2->v.kid; |
731 |
efree(ep2); |
732 |
return(ep1); |
733 |
} |
734 |
ep1 = newnode(); |
735 |
ep1->type = UMINUS; |
736 |
addekid(ep1, ep2); |
737 |
return(ep1); |
738 |
} |
739 |
if (nextc == '+') |
740 |
scan(); |
741 |
return(getE5()); |
742 |
} |
743 |
|
744 |
|
745 |
EPNODE * |
746 |
getE5(void) /* E5 -> (E1) */ |
747 |
/* VAR */ |
748 |
/* NUM */ |
749 |
/* $N */ |
750 |
/* FUNC(E1,..) */ |
751 |
/* ARG */ |
752 |
{ |
753 |
int i; |
754 |
char *nam; |
755 |
EPNODE *ep1, *ep2; |
756 |
|
757 |
if (nextc == '(') { |
758 |
scan(); |
759 |
ep1 = getE1(); |
760 |
if (nextc != ')') |
761 |
syntax("')' expected"); |
762 |
scan(); |
763 |
return(ep1); |
764 |
} |
765 |
|
766 |
if (esupport&E_INCHAN && nextc == '$') { |
767 |
scan(); |
768 |
ep1 = newnode(); |
769 |
ep1->type = CHAN; |
770 |
ep1->v.chan = getinum(); |
771 |
return(ep1); |
772 |
} |
773 |
|
774 |
if (esupport&(E_VARIABLE|E_FUNCTION) && |
775 |
(isalpha(nextc) | (nextc == CNTXMARK))) { |
776 |
nam = getname(); |
777 |
ep1 = NULL; |
778 |
if ((esupport&(E_VARIABLE|E_FUNCTION)) == (E_VARIABLE|E_FUNCTION) |
779 |
&& curfunc != NULL) |
780 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
781 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
782 |
if (!strcmp(ep2->v.name, nam)) { |
783 |
ep1 = newnode(); |
784 |
ep1->type = ARG; |
785 |
ep1->v.chan = i; |
786 |
break; |
787 |
} |
788 |
if (ep1 == NULL) { |
789 |
ep1 = newnode(); |
790 |
ep1->type = VAR; |
791 |
ep1->v.ln = varinsert(nam); |
792 |
} |
793 |
if (esupport&E_FUNCTION && nextc == '(') { |
794 |
ep2 = newnode(); |
795 |
ep2->type = FUNC; |
796 |
addekid(ep2, ep1); |
797 |
ep1 = ep2; |
798 |
do { |
799 |
scan(); |
800 |
addekid(ep1, getE1()); |
801 |
} while (nextc == ','); |
802 |
if (nextc != ')') |
803 |
syntax("')' expected"); |
804 |
scan(); |
805 |
} else if (!(esupport&E_VARIABLE)) |
806 |
syntax("'(' expected"); |
807 |
if (esupport&E_RCONST && isconstvar(ep1)) |
808 |
ep1 = rconst(ep1); |
809 |
return(ep1); |
810 |
} |
811 |
|
812 |
if (isdecimal(nextc)) { |
813 |
ep1 = newnode(); |
814 |
ep1->type = NUM; |
815 |
ep1->v.num = getnum(); |
816 |
return(ep1); |
817 |
} |
818 |
syntax("unexpected character"); |
819 |
return NULL; /* pro forma return */ |
820 |
} |
821 |
|
822 |
|
823 |
EPNODE * |
824 |
rconst( /* reduce a constant expression */ |
825 |
EPNODE *epar |
826 |
) |
827 |
{ |
828 |
EPNODE *ep; |
829 |
|
830 |
ep = newnode(); |
831 |
ep->type = NUM; |
832 |
errno = 0; |
833 |
ep->v.num = evalue(epar); |
834 |
if ((errno == EDOM) | (errno == ERANGE)) |
835 |
syntax("bad constant expression"); |
836 |
epfree(epar,1); |
837 |
|
838 |
return(ep); |
839 |
} |
840 |
|
841 |
|
842 |
int |
843 |
isconstvar( /* is ep linked to a constant expression? */ |
844 |
EPNODE *ep |
845 |
) |
846 |
{ |
847 |
EPNODE *ep1; |
848 |
|
849 |
if (esupport&E_FUNCTION && ep->type == FUNC) { |
850 |
if (!isconstfun(ep->v.kid)) |
851 |
return(0); |
852 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
853 |
if (ep1->type != NUM && !isconstfun(ep1)) |
854 |
return(0); |
855 |
return(1); |
856 |
} |
857 |
if (ep->type != VAR) |
858 |
return(0); |
859 |
ep1 = ep->v.ln->def; |
860 |
if (ep1 == NULL || ep1->type != ':') |
861 |
return(0); |
862 |
if (esupport&E_FUNCTION && ep1->v.kid->type != SYM) |
863 |
return(0); |
864 |
return(1); |
865 |
} |
866 |
|
867 |
|
868 |
int |
869 |
isconstfun( /* is ep linked to a constant function? */ |
870 |
EPNODE *ep |
871 |
) |
872 |
{ |
873 |
EPNODE *dp; |
874 |
LIBR *lp; |
875 |
|
876 |
if (ep->type != VAR) |
877 |
return(0); |
878 |
if ((dp = ep->v.ln->def) != NULL) { |
879 |
if (dp->v.kid->type == FUNC) |
880 |
return(dp->type == ':'); |
881 |
else |
882 |
return(0); /* don't identify masked library functions */ |
883 |
} |
884 |
if ((lp = ep->v.ln->lib) != NULL) |
885 |
return(lp->atyp == ':'); |
886 |
return(0); |
887 |
} |