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root/radiance/ray/src/common/caldefn.c
Revision: 1.13
Committed: Thu Aug 8 11:22:06 1991 UTC (32 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.12: +118 -27 lines
Log Message:
added contexts to definition naming

File Contents

# Content
1 /* Copyright (c) 1991 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * Store variable definitions.
9 *
10 * 7/1/85 Greg Ward
11 *
12 * 11/11/85 Added conditional compiles (OUTCHAN) for control output.
13 *
14 * 4/2/86 Added conditional compiles for function definitions (FUNCTION).
15 *
16 * 1/15/88 Added clock for caching of variable values.
17 *
18 * 11/16/88 Added VARDEF structure for hard linking.
19 *
20 * 5/31/90 Added conditional compile (REDEFW) for redefinition warning.
21 *
22 * 4/23/91 Added ':' assignment for constant expressions
23 *
24 * 8/7/91 Added optional context path to append to variable names
25 */
26
27 #include <stdio.h>
28
29 #include <ctype.h>
30
31 #include "calcomp.h"
32
33 #ifndef NHASH
34 #define NHASH 521 /* hash size (a prime!) */
35 #endif
36
37 #define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE))
38
39 extern char *ecalloc(), *savestr(), *strcpy();
40
41 static double dvalue();
42
43 long eclock = -1; /* value storage timer */
44
45 static char context[MAXWORD]; /* current context path */
46
47 static VARDEF *hashtbl[NHASH]; /* definition list */
48 static int htndx; /* index for */
49 static VARDEF *htpos; /* ...dfirst() and */
50 #ifdef OUTCHAN
51 static EPNODE *ochpos; /* ...dnext */
52 static EPNODE *outchan;
53 #endif
54
55 #ifdef FUNCTION
56 EPNODE *curfunc;
57 #define dname(ep) ((ep)->v.kid->type == SYM ? \
58 (ep)->v.kid->v.name : \
59 (ep)->v.kid->v.kid->v.name)
60 #else
61 #define dname(ep) ((ep)->v.kid->v.name)
62 #endif
63
64
65 fcompile(fname) /* get definitions from a file */
66 char *fname;
67 {
68 FILE *fp;
69
70 if (fname == NULL)
71 fp = stdin;
72 else if ((fp = fopen(fname, "r")) == NULL) {
73 eputs(fname);
74 eputs(": cannot open\n");
75 quit(1);
76 }
77 initfile(fp, fname, 0);
78 while (nextc != EOF)
79 getstatement();
80 if (fname != NULL)
81 fclose(fp);
82 }
83
84
85 scompile(str, fn, ln) /* get definitions from a string */
86 char *str;
87 char *fn;
88 int ln;
89 {
90 initstr(str, fn, ln);
91 while (nextc != EOF)
92 getstatement();
93 }
94
95
96 double
97 varvalue(vname) /* return a variable's value */
98 char *vname;
99 {
100 return(dvalue(vname, dlookup(vname)));
101 }
102
103
104 double
105 evariable(ep) /* evaluate a variable */
106 EPNODE *ep;
107 {
108 register VARDEF *dp = ep->v.ln;
109
110 return(dvalue(dp->name, dp->def));
111 }
112
113
114 varset(vname, assign, val) /* set a variable's value */
115 char *vname;
116 int assign;
117 double val;
118 {
119 char *qname;
120 register EPNODE *ep1, *ep2;
121 /* get qualified name */
122 qname = qualname(vname, 0);
123 /* check for quick set */
124 if ((ep1 = dlookup(qname)) != NULL && ep1->v.kid->type == SYM) {
125 ep2 = ep1->v.kid->sibling;
126 if (ep2->type == NUM) {
127 ep2->v.num = val;
128 ep1->type = assign;
129 return;
130 }
131 }
132 /* hand build definition */
133 ep1 = newnode();
134 ep1->type = assign;
135 ep2 = newnode();
136 ep2->type = SYM;
137 ep2->v.name = savestr(vname);
138 addekid(ep1, ep2);
139 ep2 = newnode();
140 ep2->type = NUM;
141 ep2->v.num = val;
142 addekid(ep1, ep2);
143 dremove(qname);
144 dpush(qname, ep1);
145 }
146
147
148 dclear(name) /* delete variable definitions of name */
149 char *name;
150 {
151 register EPNODE *ep;
152
153 while ((ep = dpop(name)) != NULL) {
154 if (ep->type == ':') {
155 dpush(name, ep); /* don't clear constants */
156 return;
157 }
158 epfree(ep);
159 }
160 }
161
162
163 dremove(name) /* delete all definitions of name */
164 char *name;
165 {
166 register EPNODE *ep;
167
168 while ((ep = dpop(name)) != NULL)
169 epfree(ep);
170 }
171
172
173 vardefined(name) /* return non-zero if variable defined */
174 char *name;
175 {
176 register EPNODE *dp;
177
178 return((dp = dlookup(name)) != NULL && dp->v.kid->type == SYM);
179 }
180
181
182 char *
183 setcontext(ctx) /* set a new context path */
184 register char *ctx;
185 {
186 register char *cpp;
187
188 if (ctx == NULL)
189 return(context); /* just asking */
190 if (!*ctx) {
191 context[0] = '\0'; /* clear context */
192 return(context);
193 }
194 cpp = context; /* else copy it (carefully!) */
195 if (*ctx != CNTXMARK)
196 *cpp++ = CNTXMARK; /* make sure there's a mark */
197 do {
198 if (cpp >= context+MAXWORD-1) {
199 *cpp = '\0';
200 wputs(context);
201 wputs(": context path too long\n");
202 return(NULL);
203 }
204 if (isid(*ctx))
205 *cpp++ = *ctx++;
206 else {
207 *cpp++ = '_'; ctx++;
208 }
209 } while (*ctx);
210 *cpp = '\0';
211 return(context);
212 }
213
214
215 char *
216 qualname(nam, lvl) /* get qualified name */
217 register char *nam;
218 int lvl;
219 {
220 static char nambuf[MAXWORD];
221 register char *cp = nambuf, *cpp = context;
222 /* check for repeat call */
223 if (nam == nambuf)
224 return(lvl > 0 ? NULL : nambuf);
225 /* copy name to static buffer */
226 while (*nam) {
227 if (cp >= nambuf+MAXWORD-1)
228 goto toolong;
229 if ((*cp++ = *nam++) == CNTXMARK)
230 cpp = NULL; /* flag a qualified name */
231 }
232 if (cpp == NULL) {
233 if (lvl > 0)
234 return(NULL); /* no higher level */
235 if (cp[-1] == CNTXMARK) {
236 cp--; cpp = context; /* current context explicitly */
237 } else
238 cpp = ""; /* else fully qualified */
239 } else /* else skip the requested levels */
240 while (lvl-- > 0) {
241 if (!*cpp)
242 return(NULL); /* return NULL if past global level */
243 while (*++cpp && *cpp != CNTXMARK)
244 ;
245 }
246 while (*cpp) { /* copy context to static buffer */
247 if (cp >= nambuf+MAXWORD-1)
248 goto toolong;
249 *cp++ = *cpp++;
250 }
251 *cp = '\0';
252 return(nambuf); /* return qualified name */
253 toolong:
254 *cp = '\0';
255 wputs(nambuf);
256 wputs(": name too long\n");
257 return(NULL);
258 }
259
260
261 #ifdef OUTCHAN
262 chanout(cs) /* set output channels */
263 int (*cs)();
264 {
265 register EPNODE *ep;
266
267 for (ep = outchan; ep != NULL; ep = ep->sibling)
268 (*cs)(ep->v.kid->v.chan, evalue(ep->v.kid->sibling));
269
270 }
271 #endif
272
273
274 dcleanup(lvl) /* clear definitions (0->vars,1->output,2->consts) */
275 int lvl;
276 {
277 register int i;
278 register VARDEF *vp;
279 register EPNODE *ep;
280
281 for (i = 0; i < NHASH; i++)
282 for (vp = hashtbl[i]; vp != NULL; vp = vp->next)
283 if (lvl >= 2)
284 dremove(vp->name);
285 else
286 dclear(vp->name);
287 #ifdef OUTCHAN
288 if (lvl >= 1) {
289 for (ep = outchan; ep != NULL; ep = ep->sibling)
290 epfree(ep);
291 outchan = NULL;
292 }
293 #endif
294 }
295
296
297 EPNODE *
298 dlookup(name) /* look up a definition */
299 char *name;
300 {
301 register VARDEF *vp;
302
303 if ((vp = varlookup(name)) == NULL)
304 return(NULL);
305 return(vp->def);
306 }
307
308
309 VARDEF *
310 varlookup(name) /* look up a variable */
311 char *name;
312 {
313 int lvl = 0;
314 register char *qname;
315 register VARDEF *vp;
316 /* find most qualified match */
317 while ((qname = qualname(name, lvl++)) != NULL)
318 for (vp = hashtbl[hash(qname)]; vp != NULL; vp = vp->next)
319 if (!strcmp(vp->name, qname))
320 return(vp);
321 return(NULL);
322 }
323
324
325 VARDEF *
326 varinsert(name) /* get a link to a variable */
327 char *name;
328 {
329 register VARDEF *vp;
330 int hv;
331
332 if ((vp = varlookup(name)) != NULL) {
333 vp->nlinks++;
334 return(vp);
335 }
336 name = qualname(name, 0); /* use fully qualified name */
337 hv = hash(name);
338 vp = (VARDEF *)emalloc(sizeof(VARDEF));
339 vp->name = savestr(name);
340 vp->nlinks = 1;
341 vp->def = NULL;
342 vp->lib = NULL;
343 vp->next = hashtbl[hv];
344 hashtbl[hv] = vp;
345 return(vp);
346 }
347
348
349 varfree(ln) /* release link to variable */
350 register VARDEF *ln;
351 {
352 register VARDEF *vp;
353 int hv;
354
355 if (--ln->nlinks > 0)
356 return; /* still active */
357
358 hv = hash(ln->name);
359 vp = hashtbl[hv];
360 if (vp == ln)
361 hashtbl[hv] = vp->next;
362 else {
363 while (vp->next != ln) /* must be in list */
364 vp = vp->next;
365 vp->next = ln->next;
366 }
367 freestr(ln->name);
368 efree((char *)ln);
369 }
370
371
372 EPNODE *
373 dfirst() /* return pointer to first definition */
374 {
375 htndx = 0;
376 htpos = NULL;
377 #ifdef OUTCHAN
378 ochpos = outchan;
379 #endif
380 return(dnext());
381 }
382
383
384 EPNODE *
385 dnext() /* return pointer to next definition */
386 {
387 register EPNODE *ep;
388
389 while (htndx < NHASH) {
390 if (htpos == NULL)
391 htpos = hashtbl[htndx++];
392 while (htpos != NULL) {
393 ep = htpos->def;
394 htpos = htpos->next;
395 if (ep != NULL)
396 return(ep);
397 }
398 }
399 #ifdef OUTCHAN
400 if ((ep = ochpos) != NULL)
401 ochpos = ep->sibling;
402 return(ep);
403 #else
404 return(NULL);
405 #endif
406 }
407
408
409 EPNODE *
410 dpop(name) /* pop a definition */
411 char *name;
412 {
413 register VARDEF *vp;
414 register EPNODE *dp;
415
416 if ((vp = varlookup(name)) == NULL || vp->def == NULL)
417 return(NULL);
418 dp = vp->def;
419 vp->def = dp->sibling;
420 varfree(vp);
421 return(dp);
422 }
423
424
425 dpush(nm, ep) /* push on a definition */
426 char *nm;
427 register EPNODE *ep;
428 {
429 register VARDEF *vp;
430
431 vp = varinsert(nm);
432 ep->sibling = vp->def;
433 vp->def = ep;
434 }
435
436
437 #ifdef OUTCHAN
438 addchan(sp) /* add an output channel assignment */
439 EPNODE *sp;
440 {
441 int ch = sp->v.kid->v.chan;
442 register EPNODE *ep, *epl;
443
444 for (epl = NULL, ep = outchan; ep != NULL; epl = ep, ep = ep->sibling)
445 if (ep->v.kid->v.chan >= ch) {
446 if (epl != NULL)
447 epl->sibling = sp;
448 else
449 outchan = sp;
450 if (ep->v.kid->v.chan > ch)
451 sp->sibling = ep;
452 else {
453 sp->sibling = ep->sibling;
454 epfree(ep);
455 }
456 return;
457 }
458 if (epl != NULL)
459 epl->sibling = sp;
460 else
461 outchan = sp;
462 sp->sibling = NULL;
463
464 }
465 #endif
466
467
468 getstatement() /* get next statement */
469 {
470 register EPNODE *ep;
471 char *qname;
472 EPNODE *lastdef;
473
474 if (nextc == ';') { /* empty statement */
475 scan();
476 return;
477 }
478 #ifdef OUTCHAN
479 if (nextc == '$') { /* channel assignment */
480 ep = getchan();
481 addchan(ep);
482 } else
483 #endif
484 { /* ordinary definition */
485 ep = getdefn();
486 qname = qualname(dname(ep), 0);
487 #ifdef REDEFW
488 if ((lastdef = dlookup(qname)) != NULL) {
489 wputs(qname);
490 if (lastdef->type == ':')
491 wputs(": redefined constant expression\n");
492 else
493 wputs(": redefined\n");
494 }
495 #ifdef FUNCTION
496 else if (ep->v.kid->type == FUNC && liblookup(qname) != NULL) {
497 wputs(qname);
498 wputs(": definition hides library function\n");
499 }
500 #endif
501 #endif
502 if (ep->type == ':')
503 dremove(qname);
504 else
505 dclear(qname);
506 dpush(qname, ep);
507 }
508 if (nextc != EOF) {
509 if (nextc != ';')
510 syntax("';' expected");
511 scan();
512 }
513 }
514
515
516 EPNODE *
517 getdefn() /* A -> SYM = E1 */
518 /* SYM : E1 */
519 /* FUNC(SYM,..) = E1 */
520 /* FUNC(SYM,..) : E1 */
521 {
522 register EPNODE *ep1, *ep2;
523
524 if (!isalpha(nextc))
525 syntax("illegal variable name");
526
527 ep1 = newnode();
528 ep1->type = SYM;
529 ep1->v.name = savestr(getname());
530
531 #ifdef FUNCTION
532 if (nextc == '(') {
533 ep2 = newnode();
534 ep2->type = FUNC;
535 addekid(ep2, ep1);
536 ep1 = ep2;
537 do {
538 scan();
539 if (!isalpha(nextc))
540 syntax("illegal variable name");
541 ep2 = newnode();
542 ep2->type = SYM;
543 ep2->v.name = savestr(getname());
544 addekid(ep1, ep2);
545 } while (nextc == ',');
546 if (nextc != ')')
547 syntax("')' expected");
548 scan();
549 curfunc = ep1;
550 } else
551 curfunc = NULL;
552 #endif
553
554 if (nextc != '=' && nextc != ':')
555 syntax("'=' or ':' expected");
556
557 ep2 = newnode();
558 ep2->type = nextc;
559 scan();
560 addekid(ep2, ep1);
561 addekid(ep2, getE1());
562
563 if (
564 #ifdef FUNCTION
565 ep1->type == SYM &&
566 #endif
567 ep1->sibling->type != NUM) {
568 ep1 = newnode();
569 ep1->type = TICK;
570 ep1->v.tick = -1;
571 addekid(ep2, ep1);
572 ep1 = newnode();
573 ep1->type = NUM;
574 addekid(ep2, ep1);
575 }
576
577 return(ep2);
578 }
579
580
581 #ifdef OUTCHAN
582 EPNODE *
583 getchan() /* A -> $N = E1 */
584 {
585 register EPNODE *ep1, *ep2;
586
587 if (nextc != '$')
588 syntax("missing '$'");
589 scan();
590
591 ep1 = newnode();
592 ep1->type = CHAN;
593 ep1->v.chan = getinum();
594
595 if (nextc != '=')
596 syntax("'=' expected");
597 scan();
598
599 ep2 = newnode();
600 ep2->type = '=';
601 addekid(ep2, ep1);
602 addekid(ep2, getE1());
603
604 return(ep2);
605 }
606 #endif
607
608
609
610 /*
611 * The following routines are for internal use only:
612 */
613
614
615 static double
616 dvalue(name, d) /* evaluate a variable */
617 char *name;
618 EPNODE *d;
619 {
620 register EPNODE *ep1, *ep2;
621
622 if (d == NULL || d->v.kid->type != SYM) {
623 eputs(name);
624 eputs(": undefined variable\n");
625 quit(1);
626 }
627 ep1 = d->v.kid->sibling; /* get expression */
628 if (ep1->type == NUM)
629 return(ep1->v.num); /* return if number */
630 ep2 = ep1->sibling; /* check time */
631 if (ep2->v.tick < 0 || ep2->v.tick < eclock) {
632 ep2->v.tick = d->type == ':' ? 1L<<30 : eclock;
633 ep2 = ep2->sibling;
634 ep2->v.num = evalue(ep1); /* needs new value */
635 } else
636 ep2 = ep2->sibling; /* else reuse old value */
637
638 return(ep2->v.num);
639 }
640
641
642 static int
643 hash(s) /* hash a string */
644 register char *s;
645 {
646 register int rval = 0;
647
648 while (*s)
649 rval += *s++;
650
651 return(rval % NHASH);
652 }