1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id$"; |
3 |
#endif |
4 |
/* |
5 |
* Store variable definitions. |
6 |
* |
7 |
* 7/1/85 Greg Ward |
8 |
* |
9 |
* 11/11/85 Added conditional compiles (OUTCHAN) for control output. |
10 |
* |
11 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
12 |
* |
13 |
* 1/15/88 Added clock for caching of variable values. |
14 |
* |
15 |
* 11/16/88 Added VARDEF structure for hard linking. |
16 |
* |
17 |
* 5/31/90 Added conditional compile (REDEFW) for redefinition warning. |
18 |
* |
19 |
* 4/23/91 Added ':' assignment for constant expressions |
20 |
* |
21 |
* 8/7/91 Added optional context path to append to variable names |
22 |
* |
23 |
* 5/17/2001 Fixed clock counter wrapping behavior |
24 |
* |
25 |
* 2/19/03 Eliminated conditional compiles in favor of esupport extern. |
26 |
*/ |
27 |
|
28 |
#include "copyright.h" |
29 |
|
30 |
#include <stdio.h> |
31 |
|
32 |
#include <string.h> |
33 |
|
34 |
#include <ctype.h> |
35 |
|
36 |
#include "calcomp.h" |
37 |
|
38 |
#ifndef NHASH |
39 |
#define NHASH 521 /* hash size (a prime!) */ |
40 |
#endif |
41 |
|
42 |
#define hash(s) (shash(s)%NHASH) |
43 |
|
44 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
45 |
|
46 |
static double dvalue(); |
47 |
|
48 |
#define MAXCLOCK (1L<<31) /* clock wrap value */ |
49 |
|
50 |
unsigned long eclock = 0; /* value storage timer */ |
51 |
|
52 |
#define MAXCNTX 1023 /* maximum context length */ |
53 |
|
54 |
static char context[MAXCNTX+1]; /* current context path */ |
55 |
|
56 |
static VARDEF *hashtbl[NHASH]; /* definition list */ |
57 |
static int htndx; /* index for */ |
58 |
static VARDEF *htpos; /* ...dfirst() and */ |
59 |
static EPNODE *ochpos; /* ...dnext */ |
60 |
static EPNODE *outchan; |
61 |
|
62 |
EPNODE *curfunc = NULL; |
63 |
#define dname(ep) ((ep)->v.kid->type == SYM ? \ |
64 |
(ep)->v.kid->v.name : \ |
65 |
(ep)->v.kid->v.kid->v.name) |
66 |
|
67 |
|
68 |
void |
69 |
fcompile(fname) /* get definitions from a file */ |
70 |
char *fname; |
71 |
{ |
72 |
FILE *fp; |
73 |
|
74 |
if (fname == NULL) |
75 |
fp = stdin; |
76 |
else if ((fp = fopen(fname, "r")) == NULL) { |
77 |
eputs(fname); |
78 |
eputs(": cannot open\n"); |
79 |
quit(1); |
80 |
} |
81 |
initfile(fp, fname, 0); |
82 |
while (nextc != EOF) |
83 |
getstatement(); |
84 |
if (fname != NULL) |
85 |
fclose(fp); |
86 |
} |
87 |
|
88 |
|
89 |
void |
90 |
scompile(str, fn, ln) /* get definitions from a string */ |
91 |
char *str; |
92 |
char *fn; |
93 |
int ln; |
94 |
{ |
95 |
initstr(str, fn, ln); |
96 |
while (nextc != EOF) |
97 |
getstatement(); |
98 |
} |
99 |
|
100 |
|
101 |
double |
102 |
varvalue(vname) /* return a variable's value */ |
103 |
char *vname; |
104 |
{ |
105 |
return(dvalue(vname, dlookup(vname))); |
106 |
} |
107 |
|
108 |
|
109 |
double |
110 |
evariable(ep) /* evaluate a variable */ |
111 |
EPNODE *ep; |
112 |
{ |
113 |
register VARDEF *dp = ep->v.ln; |
114 |
|
115 |
return(dvalue(dp->name, dp->def)); |
116 |
} |
117 |
|
118 |
|
119 |
void |
120 |
varset(vname, assign, val) /* set a variable's value */ |
121 |
char *vname; |
122 |
int assign; |
123 |
double val; |
124 |
{ |
125 |
char *qname; |
126 |
register EPNODE *ep1, *ep2; |
127 |
/* get qualified name */ |
128 |
qname = qualname(vname, 0); |
129 |
/* check for quick set */ |
130 |
if ((ep1 = dlookup(qname)) != NULL && ep1->v.kid->type == SYM) { |
131 |
ep2 = ep1->v.kid->sibling; |
132 |
if (ep2->type == NUM) { |
133 |
ep2->v.num = val; |
134 |
ep1->type = assign; |
135 |
return; |
136 |
} |
137 |
} |
138 |
/* hand build definition */ |
139 |
ep1 = newnode(); |
140 |
ep1->type = assign; |
141 |
ep2 = newnode(); |
142 |
ep2->type = SYM; |
143 |
ep2->v.name = savestr(vname); |
144 |
addekid(ep1, ep2); |
145 |
ep2 = newnode(); |
146 |
ep2->type = NUM; |
147 |
ep2->v.num = val; |
148 |
addekid(ep1, ep2); |
149 |
dremove(qname); |
150 |
dpush(qname, ep1); |
151 |
} |
152 |
|
153 |
|
154 |
void |
155 |
dclear(name) /* delete variable definitions of name */ |
156 |
char *name; |
157 |
{ |
158 |
register EPNODE *ep; |
159 |
|
160 |
while ((ep = dpop(name)) != NULL) { |
161 |
if (ep->type == ':') { |
162 |
dpush(name, ep); /* don't clear constants */ |
163 |
return; |
164 |
} |
165 |
epfree(ep); |
166 |
} |
167 |
} |
168 |
|
169 |
|
170 |
void |
171 |
dremove(name) /* delete all definitions of name */ |
172 |
char *name; |
173 |
{ |
174 |
register EPNODE *ep; |
175 |
|
176 |
while ((ep = dpop(name)) != NULL) |
177 |
epfree(ep); |
178 |
} |
179 |
|
180 |
|
181 |
int |
182 |
vardefined(name) /* return non-zero if variable defined */ |
183 |
char *name; |
184 |
{ |
185 |
register EPNODE *dp; |
186 |
|
187 |
return((dp = dlookup(name)) != NULL && dp->v.kid->type == SYM); |
188 |
} |
189 |
|
190 |
|
191 |
char * |
192 |
setcontext(ctx) /* set a new context path */ |
193 |
register char *ctx; |
194 |
{ |
195 |
register char *cpp; |
196 |
|
197 |
if (ctx == NULL) |
198 |
return(context); /* just asking */ |
199 |
while (*ctx == CNTXMARK) |
200 |
ctx++; /* skip past marks */ |
201 |
if (!*ctx) { |
202 |
context[0] = '\0'; /* empty means clear context */ |
203 |
return(context); |
204 |
} |
205 |
cpp = context; /* start context with mark */ |
206 |
*cpp++ = CNTXMARK; |
207 |
do { /* carefully copy new context */ |
208 |
if (cpp >= context+MAXCNTX) |
209 |
break; /* just copy what we can */ |
210 |
if (isid(*ctx)) |
211 |
*cpp++ = *ctx++; |
212 |
else { |
213 |
*cpp++ = '_'; ctx++; |
214 |
} |
215 |
} while (*ctx); |
216 |
while (cpp[-1] == CNTXMARK) /* cannot end in context mark */ |
217 |
cpp--; |
218 |
*cpp = '\0'; |
219 |
return(context); |
220 |
} |
221 |
|
222 |
|
223 |
char * |
224 |
pushcontext(ctx) /* push on another context */ |
225 |
char *ctx; |
226 |
{ |
227 |
extern char *strncpy(), *strcpy(); |
228 |
char oldcontext[MAXCNTX+1]; |
229 |
register int n; |
230 |
|
231 |
strcpy(oldcontext, context); /* save old context */ |
232 |
setcontext(ctx); /* set new context */ |
233 |
n = strlen(context); /* tack on old */ |
234 |
if (n+strlen(oldcontext) > MAXCNTX) { |
235 |
strncpy(context+n, oldcontext, MAXCNTX-n); |
236 |
context[MAXCNTX] = '\0'; |
237 |
} else |
238 |
strcpy(context+n, oldcontext); |
239 |
return(context); |
240 |
} |
241 |
|
242 |
|
243 |
char * |
244 |
popcontext() /* pop off top context */ |
245 |
{ |
246 |
register char *cp1, *cp2; |
247 |
|
248 |
if (!context[0]) /* nothing left to pop */ |
249 |
return(context); |
250 |
cp2 = context; /* find mark */ |
251 |
while (*++cp2 && *cp2 != CNTXMARK) |
252 |
; |
253 |
cp1 = context; /* copy tail to front */ |
254 |
while (*cp1++ = *cp2++) |
255 |
; |
256 |
return(context); |
257 |
} |
258 |
|
259 |
|
260 |
char * |
261 |
qualname(nam, lvl) /* get qualified name */ |
262 |
register char *nam; |
263 |
int lvl; |
264 |
{ |
265 |
static char nambuf[MAXWORD+1]; |
266 |
register char *cp = nambuf, *cpp; |
267 |
/* check for explicit local */ |
268 |
if (*nam == CNTXMARK) |
269 |
if (lvl > 0) /* only action is to refuse search */ |
270 |
return(NULL); |
271 |
else |
272 |
nam++; |
273 |
else if (nam == nambuf) /* check for repeat call */ |
274 |
return(lvl > 0 ? NULL : nam); |
275 |
/* copy name to static buffer */ |
276 |
while (*nam) { |
277 |
if (cp >= nambuf+MAXWORD) |
278 |
goto toolong; |
279 |
*cp++ = *nam++; |
280 |
} |
281 |
/* check for explicit global */ |
282 |
if (cp > nambuf && cp[-1] == CNTXMARK) { |
283 |
if (lvl > 0) |
284 |
return(NULL); |
285 |
*--cp = '\0'; |
286 |
return(nambuf); /* already qualified */ |
287 |
} |
288 |
cpp = context; /* else skip the requested levels */ |
289 |
while (lvl-- > 0) { |
290 |
if (!*cpp) |
291 |
return(NULL); /* return NULL if past global level */ |
292 |
while (*++cpp && *cpp != CNTXMARK) |
293 |
; |
294 |
} |
295 |
while (*cpp) { /* copy context to static buffer */ |
296 |
if (cp >= nambuf+MAXWORD) |
297 |
goto toolong; |
298 |
*cp++ = *cpp++; |
299 |
} |
300 |
toolong: |
301 |
*cp = '\0'; |
302 |
return(nambuf); /* return qualified name */ |
303 |
} |
304 |
|
305 |
|
306 |
int |
307 |
incontext(qn) /* is qualified name in current context? */ |
308 |
register char *qn; |
309 |
{ |
310 |
if (!context[0]) /* global context accepts all */ |
311 |
return(1); |
312 |
while (*qn && *qn != CNTXMARK) /* find context mark */ |
313 |
qn++; |
314 |
return(!strcmp(qn, context)); |
315 |
} |
316 |
|
317 |
|
318 |
void |
319 |
chanout(cs) /* set output channels */ |
320 |
int (*cs)(); |
321 |
{ |
322 |
register EPNODE *ep; |
323 |
|
324 |
for (ep = outchan; ep != NULL; ep = ep->sibling) |
325 |
(*cs)(ep->v.kid->v.chan, evalue(ep->v.kid->sibling)); |
326 |
|
327 |
} |
328 |
|
329 |
|
330 |
void |
331 |
dcleanup(lvl) /* clear definitions (0->vars,1->output,2->consts) */ |
332 |
int lvl; |
333 |
{ |
334 |
register int i; |
335 |
register VARDEF *vp; |
336 |
register EPNODE *ep; |
337 |
/* if context is global, clear all */ |
338 |
for (i = 0; i < NHASH; i++) |
339 |
for (vp = hashtbl[i]; vp != NULL; vp = vp->next) |
340 |
if (incontext(vp->name)) |
341 |
if (lvl >= 2) |
342 |
dremove(vp->name); |
343 |
else |
344 |
dclear(vp->name); |
345 |
if (lvl >= 1) { |
346 |
for (ep = outchan; ep != NULL; ep = ep->sibling) |
347 |
epfree(ep); |
348 |
outchan = NULL; |
349 |
} |
350 |
} |
351 |
|
352 |
|
353 |
EPNODE * |
354 |
dlookup(name) /* look up a definition */ |
355 |
char *name; |
356 |
{ |
357 |
register VARDEF *vp; |
358 |
|
359 |
if ((vp = varlookup(name)) == NULL) |
360 |
return(NULL); |
361 |
return(vp->def); |
362 |
} |
363 |
|
364 |
|
365 |
VARDEF * |
366 |
varlookup(name) /* look up a variable */ |
367 |
char *name; |
368 |
{ |
369 |
int lvl = 0; |
370 |
register char *qname; |
371 |
register VARDEF *vp; |
372 |
/* find most qualified match */ |
373 |
while ((qname = qualname(name, lvl++)) != NULL) |
374 |
for (vp = hashtbl[hash(qname)]; vp != NULL; vp = vp->next) |
375 |
if (!strcmp(vp->name, qname)) |
376 |
return(vp); |
377 |
return(NULL); |
378 |
} |
379 |
|
380 |
|
381 |
VARDEF * |
382 |
varinsert(name) /* get a link to a variable */ |
383 |
char *name; |
384 |
{ |
385 |
register VARDEF *vp; |
386 |
int hv; |
387 |
|
388 |
if ((vp = varlookup(name)) != NULL) { |
389 |
vp->nlinks++; |
390 |
return(vp); |
391 |
} |
392 |
vp = (VARDEF *)emalloc(sizeof(VARDEF)); |
393 |
vp->lib = liblookup(name); |
394 |
if (vp->lib == NULL) /* if name not in library */ |
395 |
name = qualname(name, 0); /* use fully qualified version */ |
396 |
hv = hash(name); |
397 |
vp->name = savestr(name); |
398 |
vp->nlinks = 1; |
399 |
vp->def = NULL; |
400 |
vp->next = hashtbl[hv]; |
401 |
hashtbl[hv] = vp; |
402 |
return(vp); |
403 |
} |
404 |
|
405 |
|
406 |
void |
407 |
libupdate(fn) /* update library links */ |
408 |
char *fn; |
409 |
{ |
410 |
register int i; |
411 |
register VARDEF *vp; |
412 |
/* if fn is NULL then relink all */ |
413 |
for (i = 0; i < NHASH; i++) |
414 |
for (vp = hashtbl[i]; vp != NULL; vp = vp->next) |
415 |
if (vp->lib != NULL || fn == NULL || !strcmp(fn, vp->name)) |
416 |
vp->lib = liblookup(vp->name); |
417 |
} |
418 |
|
419 |
|
420 |
void |
421 |
varfree(ln) /* release link to variable */ |
422 |
register VARDEF *ln; |
423 |
{ |
424 |
register VARDEF *vp; |
425 |
int hv; |
426 |
|
427 |
if (--ln->nlinks > 0) |
428 |
return; /* still active */ |
429 |
|
430 |
hv = hash(ln->name); |
431 |
vp = hashtbl[hv]; |
432 |
if (vp == ln) |
433 |
hashtbl[hv] = vp->next; |
434 |
else { |
435 |
while (vp->next != ln) /* must be in list */ |
436 |
vp = vp->next; |
437 |
vp->next = ln->next; |
438 |
} |
439 |
freestr(ln->name); |
440 |
efree((char *)ln); |
441 |
} |
442 |
|
443 |
|
444 |
EPNODE * |
445 |
dfirst() /* return pointer to first definition */ |
446 |
{ |
447 |
htndx = 0; |
448 |
htpos = NULL; |
449 |
ochpos = outchan; |
450 |
return(dnext()); |
451 |
} |
452 |
|
453 |
|
454 |
EPNODE * |
455 |
dnext() /* return pointer to next definition */ |
456 |
{ |
457 |
register EPNODE *ep; |
458 |
register char *nm; |
459 |
|
460 |
while (htndx < NHASH) { |
461 |
if (htpos == NULL) |
462 |
htpos = hashtbl[htndx++]; |
463 |
while (htpos != NULL) { |
464 |
ep = htpos->def; |
465 |
nm = htpos->name; |
466 |
htpos = htpos->next; |
467 |
if (ep != NULL && incontext(nm)) |
468 |
return(ep); |
469 |
} |
470 |
} |
471 |
if ((ep = ochpos) != NULL) |
472 |
ochpos = ep->sibling; |
473 |
return(ep); |
474 |
} |
475 |
|
476 |
|
477 |
EPNODE * |
478 |
dpop(name) /* pop a definition */ |
479 |
char *name; |
480 |
{ |
481 |
register VARDEF *vp; |
482 |
register EPNODE *dp; |
483 |
|
484 |
if ((vp = varlookup(name)) == NULL || vp->def == NULL) |
485 |
return(NULL); |
486 |
dp = vp->def; |
487 |
vp->def = dp->sibling; |
488 |
varfree(vp); |
489 |
return(dp); |
490 |
} |
491 |
|
492 |
|
493 |
void |
494 |
dpush(nm, ep) /* push on a definition */ |
495 |
char *nm; |
496 |
register EPNODE *ep; |
497 |
{ |
498 |
register VARDEF *vp; |
499 |
|
500 |
vp = varinsert(nm); |
501 |
ep->sibling = vp->def; |
502 |
vp->def = ep; |
503 |
} |
504 |
|
505 |
|
506 |
void |
507 |
addchan(sp) /* add an output channel assignment */ |
508 |
EPNODE *sp; |
509 |
{ |
510 |
int ch = sp->v.kid->v.chan; |
511 |
register EPNODE *ep, *epl; |
512 |
|
513 |
for (epl = NULL, ep = outchan; ep != NULL; epl = ep, ep = ep->sibling) |
514 |
if (ep->v.kid->v.chan >= ch) { |
515 |
if (epl != NULL) |
516 |
epl->sibling = sp; |
517 |
else |
518 |
outchan = sp; |
519 |
if (ep->v.kid->v.chan > ch) |
520 |
sp->sibling = ep; |
521 |
else { |
522 |
sp->sibling = ep->sibling; |
523 |
epfree(ep); |
524 |
} |
525 |
return; |
526 |
} |
527 |
if (epl != NULL) |
528 |
epl->sibling = sp; |
529 |
else |
530 |
outchan = sp; |
531 |
sp->sibling = NULL; |
532 |
|
533 |
} |
534 |
|
535 |
|
536 |
void |
537 |
getstatement() /* get next statement */ |
538 |
{ |
539 |
register EPNODE *ep; |
540 |
char *qname; |
541 |
register VARDEF *vdef; |
542 |
|
543 |
if (nextc == ';') { /* empty statement */ |
544 |
scan(); |
545 |
return; |
546 |
} |
547 |
if (esupport&E_OUTCHAN && |
548 |
nextc == '$') { /* channel assignment */ |
549 |
ep = getchan(); |
550 |
addchan(ep); |
551 |
} else { /* ordinary definition */ |
552 |
ep = getdefn(); |
553 |
qname = qualname(dname(ep), 0); |
554 |
if (esupport&E_REDEFW && (vdef = varlookup(qname)) != NULL) |
555 |
if (vdef->def != NULL && epcmp(ep, vdef->def)) { |
556 |
wputs(qname); |
557 |
if (vdef->def->type == ':') |
558 |
wputs(": redefined constant expression\n"); |
559 |
else |
560 |
wputs(": redefined\n"); |
561 |
} else if (ep->v.kid->type == FUNC && vdef->lib != NULL) { |
562 |
wputs(qname); |
563 |
wputs(": definition hides library function\n"); |
564 |
} |
565 |
if (ep->type == ':') |
566 |
dremove(qname); |
567 |
else |
568 |
dclear(qname); |
569 |
dpush(qname, ep); |
570 |
} |
571 |
if (nextc != EOF) { |
572 |
if (nextc != ';') |
573 |
syntax("';' expected"); |
574 |
scan(); |
575 |
} |
576 |
} |
577 |
|
578 |
|
579 |
EPNODE * |
580 |
getdefn() /* A -> SYM = E1 */ |
581 |
/* SYM : E1 */ |
582 |
/* FUNC(SYM,..) = E1 */ |
583 |
/* FUNC(SYM,..) : E1 */ |
584 |
{ |
585 |
register EPNODE *ep1, *ep2; |
586 |
|
587 |
if (!isalpha(nextc) && nextc != CNTXMARK) |
588 |
syntax("illegal variable name"); |
589 |
|
590 |
ep1 = newnode(); |
591 |
ep1->type = SYM; |
592 |
ep1->v.name = savestr(getname()); |
593 |
|
594 |
if (esupport&E_FUNCTION && nextc == '(') { |
595 |
ep2 = newnode(); |
596 |
ep2->type = FUNC; |
597 |
addekid(ep2, ep1); |
598 |
ep1 = ep2; |
599 |
do { |
600 |
scan(); |
601 |
if (!isalpha(nextc)) |
602 |
syntax("illegal variable name"); |
603 |
ep2 = newnode(); |
604 |
ep2->type = SYM; |
605 |
ep2->v.name = savestr(getname()); |
606 |
addekid(ep1, ep2); |
607 |
} while (nextc == ','); |
608 |
if (nextc != ')') |
609 |
syntax("')' expected"); |
610 |
scan(); |
611 |
curfunc = ep1; |
612 |
} |
613 |
|
614 |
if (nextc != '=' && nextc != ':') |
615 |
syntax("'=' or ':' expected"); |
616 |
|
617 |
ep2 = newnode(); |
618 |
ep2->type = nextc; |
619 |
scan(); |
620 |
addekid(ep2, ep1); |
621 |
addekid(ep2, getE1()); |
622 |
|
623 |
if (ep1->type == SYM && ep1->sibling->type != NUM) { |
624 |
ep1 = newnode(); |
625 |
ep1->type = TICK; |
626 |
ep1->v.tick = 0; |
627 |
addekid(ep2, ep1); |
628 |
ep1 = newnode(); |
629 |
ep1->type = NUM; |
630 |
addekid(ep2, ep1); |
631 |
} |
632 |
curfunc = NULL; |
633 |
|
634 |
return(ep2); |
635 |
} |
636 |
|
637 |
|
638 |
EPNODE * |
639 |
getchan() /* A -> $N = E1 */ |
640 |
{ |
641 |
register EPNODE *ep1, *ep2; |
642 |
|
643 |
if (nextc != '$') |
644 |
syntax("missing '$'"); |
645 |
scan(); |
646 |
|
647 |
ep1 = newnode(); |
648 |
ep1->type = CHAN; |
649 |
ep1->v.chan = getinum(); |
650 |
|
651 |
if (nextc != '=') |
652 |
syntax("'=' expected"); |
653 |
scan(); |
654 |
|
655 |
ep2 = newnode(); |
656 |
ep2->type = '='; |
657 |
addekid(ep2, ep1); |
658 |
addekid(ep2, getE1()); |
659 |
|
660 |
return(ep2); |
661 |
} |
662 |
|
663 |
|
664 |
|
665 |
/* |
666 |
* The following routines are for internal use only: |
667 |
*/ |
668 |
|
669 |
|
670 |
static double |
671 |
dvalue(name, d) /* evaluate a variable */ |
672 |
char *name; |
673 |
EPNODE *d; |
674 |
{ |
675 |
register EPNODE *ep1, *ep2; |
676 |
|
677 |
if (d == NULL || d->v.kid->type != SYM) { |
678 |
eputs(name); |
679 |
eputs(": undefined variable\n"); |
680 |
quit(1); |
681 |
} |
682 |
ep1 = d->v.kid->sibling; /* get expression */ |
683 |
if (ep1->type == NUM) |
684 |
return(ep1->v.num); /* return if number */ |
685 |
ep2 = ep1->sibling; /* check time */ |
686 |
if (eclock >= MAXCLOCK) |
687 |
eclock = 1; /* wrap clock counter */ |
688 |
if (ep2->v.tick < MAXCLOCK && |
689 |
ep2->v.tick == 0 | ep2->v.tick != eclock) { |
690 |
ep2->v.tick = d->type == ':' ? MAXCLOCK : eclock; |
691 |
ep2 = ep2->sibling; |
692 |
ep2->v.num = evalue(ep1); /* needs new value */ |
693 |
} else |
694 |
ep2 = ep2->sibling; /* else reuse old value */ |
695 |
|
696 |
return(ep2->v.num); |
697 |
} |