0b55f123 |
1 | /***** spin: pangen6.c *****/ |
2 | |
3 | /* Copyright (c) 2000-2003 by Lucent Technologies, Bell Laboratories. */ |
4 | /* All Rights Reserved. This software is for educational purposes only. */ |
5 | /* No guarantee whatsoever is expressed or implied by the distribution of */ |
6 | /* this code. Permission is given to distribute this code provided that */ |
7 | /* this introductory message is not removed and no monies are exchanged. */ |
8 | /* Software written by Gerard J. Holzmann. For tool documentation see: */ |
9 | /* http://spinroot.com/ */ |
10 | /* Send all bug-reports and/or questions to: bugs@spinroot.com */ |
11 | |
12 | /* Abstract syntax tree analysis / slicing (spin option -A) */ |
13 | /* AST_store stores the fsms's for each proctype */ |
14 | /* AST_track keeps track of variables used in properties */ |
15 | /* AST_slice starts the slicing algorithm */ |
16 | /* it first collects more info and then calls */ |
17 | /* AST_criteria to process the slice criteria */ |
18 | |
19 | #include "spin.h" |
20 | #include "y.tab.h" |
21 | |
22 | extern Ordered *all_names; |
23 | extern FSM_use *use_free; |
24 | extern FSM_state **fsm_tbl; |
25 | extern FSM_state *fsm; |
26 | extern int verbose, o_max; |
27 | |
28 | static FSM_trans *cur_t; |
29 | static FSM_trans *expl_par; |
30 | static FSM_trans *expl_var; |
31 | static FSM_trans *explicit; |
32 | |
33 | extern void rel_use(FSM_use *); |
34 | |
35 | #define ulong unsigned long |
36 | |
37 | typedef struct Pair { |
38 | FSM_state *h; |
39 | int b; |
40 | struct Pair *nxt; |
41 | } Pair; |
42 | |
43 | typedef struct AST { |
44 | ProcList *p; /* proctype decl */ |
45 | int i_st; /* start state */ |
46 | int nstates, nwords; |
47 | int relevant; |
48 | Pair *pairs; /* entry and exit nodes of proper subgraphs */ |
49 | FSM_state *fsm; /* proctype body */ |
50 | struct AST *nxt; /* linked list */ |
51 | } AST; |
52 | |
53 | typedef struct RPN { /* relevant proctype names */ |
54 | Symbol *rn; |
55 | struct RPN *nxt; |
56 | } RPN; |
57 | |
58 | typedef struct ALIAS { /* channel aliasing info */ |
59 | Lextok *cnm; /* this chan */ |
60 | int origin; /* debugging - origin of the alias */ |
61 | struct ALIAS *alias; /* can be an alias for these other chans */ |
62 | struct ALIAS *nxt; /* linked list */ |
63 | } ALIAS; |
64 | |
65 | typedef struct ChanList { |
66 | Lextok *s; /* containing stmnt */ |
67 | Lextok *n; /* point of reference - could be struct */ |
68 | struct ChanList *nxt; /* linked list */ |
69 | } ChanList; |
70 | |
71 | /* a chan alias can be created in one of three ways: |
72 | assignement to chan name |
73 | a = b -- a is now an alias for b |
74 | passing chan name as parameter in run |
75 | run x(b) -- proctype x(chan a) |
76 | passing chan name through channel |
77 | x!b -- x?a |
78 | */ |
79 | |
80 | #define USE 1 |
81 | #define DEF 2 |
82 | #define DEREF_DEF 4 |
83 | #define DEREF_USE 8 |
84 | |
85 | static AST *ast; |
86 | static ALIAS *chalcur; |
87 | static ALIAS *chalias; |
88 | static ChanList *chanlist; |
89 | static Slicer *slicer; |
90 | static Slicer *rel_vars; /* all relevant variables */ |
91 | static int AST_Changes; |
92 | static int AST_Round; |
93 | static RPN *rpn; |
94 | static int in_recv = 0; |
95 | |
96 | static int AST_mutual(Lextok *, Lextok *, int); |
97 | static void AST_dominant(void); |
98 | static void AST_hidden(void); |
99 | static void AST_setcur(Lextok *); |
100 | static void check_slice(Lextok *, int); |
101 | static void curtail(AST *); |
102 | static void def_use(Lextok *, int); |
103 | static void name_AST_track(Lextok *, int); |
104 | static void show_expl(void); |
105 | |
106 | static int |
107 | AST_isini(Lextok *n) /* is this an initialized channel */ |
108 | { Symbol *s; |
109 | |
110 | if (!n || !n->sym) return 0; |
111 | |
112 | s = n->sym; |
113 | |
114 | if (s->type == CHAN) |
115 | return (s->ini->ntyp == CHAN); /* freshly instantiated */ |
116 | |
117 | if (s->type == STRUCT && n->rgt) |
118 | return AST_isini(n->rgt->lft); |
119 | |
120 | return 0; |
121 | } |
122 | |
123 | static void |
124 | AST_var(Lextok *n, Symbol *s, int toplevel) |
125 | { |
126 | if (!s) return; |
127 | |
128 | if (toplevel) |
129 | { if (s->context && s->type) |
130 | printf(":%s:L:", s->context->name); |
131 | else |
132 | printf("G:"); |
133 | } |
134 | printf("%s", s->name); /* array indices ignored */ |
135 | |
136 | if (s->type == STRUCT && n && n->rgt && n->rgt->lft) |
137 | { printf(":"); |
138 | AST_var(n->rgt->lft, n->rgt->lft->sym, 0); |
139 | } |
140 | } |
141 | |
142 | static void |
143 | name_def_indices(Lextok *n, int code) |
144 | { |
145 | if (!n || !n->sym) return; |
146 | |
147 | if (n->sym->nel != 1) |
148 | def_use(n->lft, code); /* process the index */ |
149 | |
150 | if (n->sym->type == STRUCT /* and possible deeper ones */ |
151 | && n->rgt) |
152 | name_def_indices(n->rgt->lft, code); |
153 | } |
154 | |
155 | static void |
156 | name_def_use(Lextok *n, int code) |
157 | { FSM_use *u; |
158 | |
159 | if (!n) return; |
160 | |
161 | if ((code&USE) |
162 | && cur_t->step |
163 | && cur_t->step->n) |
164 | { switch (cur_t->step->n->ntyp) { |
165 | case 'c': /* possible predicate abstraction? */ |
166 | n->sym->colnr |= 2; /* yes */ |
167 | break; |
168 | default: |
169 | n->sym->colnr |= 1; /* no */ |
170 | break; |
171 | } |
172 | } |
173 | |
174 | for (u = cur_t->Val[0]; u; u = u->nxt) |
175 | if (AST_mutual(n, u->n, 1) |
176 | && u->special == code) |
177 | return; |
178 | |
179 | if (use_free) |
180 | { u = use_free; |
181 | use_free = use_free->nxt; |
182 | } else |
183 | u = (FSM_use *) emalloc(sizeof(FSM_use)); |
184 | |
185 | u->n = n; |
186 | u->special = code; |
187 | u->nxt = cur_t->Val[0]; |
188 | cur_t->Val[0] = u; |
189 | |
190 | name_def_indices(n, USE|(code&(~DEF))); /* not def, but perhaps deref */ |
191 | } |
192 | |
193 | static void |
194 | def_use(Lextok *now, int code) |
195 | { Lextok *v; |
196 | |
197 | if (now) |
198 | switch (now->ntyp) { |
199 | case '!': |
200 | case UMIN: |
201 | case '~': |
202 | case 'c': |
203 | case ENABLED: |
204 | case ASSERT: |
205 | case EVAL: |
206 | def_use(now->lft, USE|code); |
207 | break; |
208 | |
209 | case LEN: |
210 | case FULL: |
211 | case EMPTY: |
212 | case NFULL: |
213 | case NEMPTY: |
214 | def_use(now->lft, DEREF_USE|USE|code); |
215 | break; |
216 | |
217 | case '/': |
218 | case '*': |
219 | case '-': |
220 | case '+': |
221 | case '%': |
222 | case '&': |
223 | case '^': |
224 | case '|': |
225 | case LE: |
226 | case GE: |
227 | case GT: |
228 | case LT: |
229 | case NE: |
230 | case EQ: |
231 | case OR: |
232 | case AND: |
233 | case LSHIFT: |
234 | case RSHIFT: |
235 | def_use(now->lft, USE|code); |
236 | def_use(now->rgt, USE|code); |
237 | break; |
238 | |
239 | case ASGN: |
240 | def_use(now->lft, DEF|code); |
241 | def_use(now->rgt, USE|code); |
242 | break; |
243 | |
244 | case TYPE: /* name in parameter list */ |
245 | name_def_use(now, code); |
246 | break; |
247 | |
248 | case NAME: |
249 | name_def_use(now, code); |
250 | break; |
251 | |
252 | case RUN: |
253 | name_def_use(now, USE); /* procname - not really needed */ |
254 | for (v = now->lft; v; v = v->rgt) |
255 | def_use(v->lft, USE); /* params */ |
256 | break; |
257 | |
258 | case 's': |
259 | def_use(now->lft, DEREF_DEF|DEREF_USE|USE|code); |
260 | for (v = now->rgt; v; v = v->rgt) |
261 | def_use(v->lft, USE|code); |
262 | break; |
263 | |
264 | case 'r': |
265 | def_use(now->lft, DEREF_DEF|DEREF_USE|USE|code); |
266 | for (v = now->rgt; v; v = v->rgt) |
267 | { if (v->lft->ntyp == EVAL) |
268 | def_use(v->lft, code); /* will add USE */ |
269 | else if (v->lft->ntyp != CONST) |
270 | def_use(v->lft, DEF|code); |
271 | } |
272 | break; |
273 | |
274 | case 'R': |
275 | def_use(now->lft, DEREF_USE|USE|code); |
276 | for (v = now->rgt; v; v = v->rgt) |
277 | { if (v->lft->ntyp == EVAL) |
278 | def_use(v->lft, code); /* will add USE */ |
279 | } |
280 | break; |
281 | |
282 | case '?': |
283 | def_use(now->lft, USE|code); |
284 | if (now->rgt) |
285 | { def_use(now->rgt->lft, code); |
286 | def_use(now->rgt->rgt, code); |
287 | } |
288 | break; |
289 | |
290 | case PRINT: |
291 | for (v = now->lft; v; v = v->rgt) |
292 | def_use(v->lft, USE|code); |
293 | break; |
294 | |
295 | case PRINTM: |
296 | def_use(now->lft, USE); |
297 | break; |
298 | |
299 | case CONST: |
300 | case ELSE: /* ? */ |
301 | case NONPROGRESS: |
302 | case PC_VAL: |
303 | case 'p': |
304 | case 'q': |
305 | break; |
306 | |
307 | case '.': |
308 | case GOTO: |
309 | case BREAK: |
310 | case '@': |
311 | case D_STEP: |
312 | case ATOMIC: |
313 | case NON_ATOMIC: |
314 | case IF: |
315 | case DO: |
316 | case UNLESS: |
317 | case TIMEOUT: |
318 | case C_CODE: |
319 | case C_EXPR: |
320 | default: |
321 | break; |
322 | } |
323 | } |
324 | |
325 | static int |
326 | AST_add_alias(Lextok *n, int nr) |
327 | { ALIAS *ca; |
328 | int res; |
329 | |
330 | for (ca = chalcur->alias; ca; ca = ca->nxt) |
331 | if (AST_mutual(ca->cnm, n, 1)) |
332 | { res = (ca->origin&nr); |
333 | ca->origin |= nr; /* 1, 2, or 4 - run, asgn, or rcv */ |
334 | return (res == 0); /* 0 if already there with same origin */ |
335 | } |
336 | |
337 | ca = (ALIAS *) emalloc(sizeof(ALIAS)); |
338 | ca->cnm = n; |
339 | ca->origin = nr; |
340 | ca->nxt = chalcur->alias; |
341 | chalcur->alias = ca; |
342 | return 1; |
343 | } |
344 | |
345 | static void |
346 | AST_run_alias(char *pn, char *s, Lextok *t, int parno) |
347 | { Lextok *v; |
348 | int cnt; |
349 | |
350 | if (!t) return; |
351 | |
352 | if (t->ntyp == RUN) |
353 | { if (strcmp(t->sym->name, s) == 0) |
354 | for (v = t->lft, cnt = 1; v; v = v->rgt, cnt++) |
355 | if (cnt == parno) |
356 | { AST_add_alias(v->lft, 1); /* RUN */ |
357 | break; |
358 | } |
359 | } else |
360 | { AST_run_alias(pn, s, t->lft, parno); |
361 | AST_run_alias(pn, s, t->rgt, parno); |
362 | } |
363 | } |
364 | |
365 | static void |
366 | AST_findrun(char *s, int parno) |
367 | { FSM_state *f; |
368 | FSM_trans *t; |
369 | AST *a; |
370 | |
371 | for (a = ast; a; a = a->nxt) /* automata */ |
372 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
373 | for (t = f->t; t; t = t->nxt) /* transitions */ |
374 | { if (t->step) |
375 | AST_run_alias(a->p->n->name, s, t->step->n, parno); |
376 | } |
377 | } |
378 | |
379 | static void |
380 | AST_par_chans(ProcList *p) /* find local chan's init'd to chan passed as param */ |
381 | { Ordered *walk; |
382 | Symbol *sp; |
383 | |
384 | for (walk = all_names; walk; walk = walk->next) |
385 | { sp = walk->entry; |
386 | if (sp |
387 | && sp->context |
388 | && strcmp(sp->context->name, p->n->name) == 0 |
389 | && sp->Nid >= 0 /* not itself a param */ |
390 | && sp->type == CHAN |
391 | && sp->ini->ntyp == NAME) /* != CONST and != CHAN */ |
392 | { Lextok *x = nn(ZN, 0, ZN, ZN); |
393 | x->sym = sp; |
394 | AST_setcur(x); |
395 | AST_add_alias(sp->ini, 2); /* ASGN */ |
396 | } } |
397 | } |
398 | |
399 | static void |
400 | AST_para(ProcList *p) |
401 | { Lextok *f, *t, *c; |
402 | int cnt = 0; |
403 | |
404 | AST_par_chans(p); |
405 | |
406 | for (f = p->p; f; f = f->rgt) /* list of types */ |
407 | for (t = f->lft; t; t = t->rgt) |
408 | { if (t->ntyp != ',') |
409 | c = t; |
410 | else |
411 | c = t->lft; /* expanded struct */ |
412 | |
413 | cnt++; |
414 | if (Sym_typ(c) == CHAN) |
415 | { ALIAS *na = (ALIAS *) emalloc(sizeof(ALIAS)); |
416 | |
417 | na->cnm = c; |
418 | na->nxt = chalias; |
419 | chalcur = chalias = na; |
420 | #if 0 |
421 | printf("%s -- (par) -- ", p->n->name); |
422 | AST_var(c, c->sym, 1); |
423 | printf(" => <<"); |
424 | #endif |
425 | AST_findrun(p->n->name, cnt); |
426 | #if 0 |
427 | printf(">>\n"); |
428 | #endif |
429 | } |
430 | } |
431 | } |
432 | |
433 | static void |
434 | AST_haschan(Lextok *c) |
435 | { |
436 | if (!c) return; |
437 | if (Sym_typ(c) == CHAN) |
438 | { AST_add_alias(c, 2); /* ASGN */ |
439 | #if 0 |
440 | printf("<<"); |
441 | AST_var(c, c->sym, 1); |
442 | printf(">>\n"); |
443 | #endif |
444 | } else |
445 | { AST_haschan(c->rgt); |
446 | AST_haschan(c->lft); |
447 | } |
448 | } |
449 | |
450 | static int |
451 | AST_nrpar(Lextok *n) /* 's' or 'r' */ |
452 | { Lextok *m; |
453 | int j = 0; |
454 | |
455 | for (m = n->rgt; m; m = m->rgt) |
456 | j++; |
457 | return j; |
458 | } |
459 | |
460 | static int |
461 | AST_ord(Lextok *n, Lextok *s) |
462 | { Lextok *m; |
463 | int j = 0; |
464 | |
465 | for (m = n->rgt; m; m = m->rgt) |
466 | { j++; |
467 | if (s->sym == m->lft->sym) |
468 | return j; |
469 | } |
470 | return 0; |
471 | } |
472 | |
473 | #if 0 |
474 | static void |
475 | AST_ownership(Symbol *s) |
476 | { |
477 | if (!s) return; |
478 | printf("%s:", s->name); |
479 | AST_ownership(s->owner); |
480 | } |
481 | #endif |
482 | |
483 | static int |
484 | AST_mutual(Lextok *a, Lextok *b, int toplevel) |
485 | { Symbol *as, *bs; |
486 | |
487 | if (!a && !b) return 1; |
488 | |
489 | if (!a || !b) return 0; |
490 | |
491 | as = a->sym; |
492 | bs = b->sym; |
493 | |
494 | if (!as || !bs) return 0; |
495 | |
496 | if (toplevel && as->context != bs->context) |
497 | return 0; |
498 | |
499 | if (as->type != bs->type) |
500 | return 0; |
501 | |
502 | if (strcmp(as->name, bs->name) != 0) |
503 | return 0; |
504 | |
505 | if (as->type == STRUCT && a->rgt && b->rgt) /* we know that a and b are not null */ |
506 | return AST_mutual(a->rgt->lft, b->rgt->lft, 0); |
507 | |
508 | return 1; |
509 | } |
510 | |
511 | static void |
512 | AST_setcur(Lextok *n) /* set chalcur */ |
513 | { ALIAS *ca; |
514 | |
515 | for (ca = chalias; ca; ca = ca->nxt) |
516 | if (AST_mutual(ca->cnm, n, 1)) /* if same chan */ |
517 | { chalcur = ca; |
518 | return; |
519 | } |
520 | |
521 | ca = (ALIAS *) emalloc(sizeof(ALIAS)); |
522 | ca->cnm = n; |
523 | ca->nxt = chalias; |
524 | chalcur = chalias = ca; |
525 | } |
526 | |
527 | static void |
528 | AST_other(AST *a) /* check chan params in asgns and recvs */ |
529 | { FSM_state *f; |
530 | FSM_trans *t; |
531 | FSM_use *u; |
532 | ChanList *cl; |
533 | |
534 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
535 | for (t = f->t; t; t = t->nxt) /* transitions */ |
536 | for (u = t->Val[0]; u; u = u->nxt) /* def/use info */ |
537 | if (Sym_typ(u->n) == CHAN |
538 | && (u->special&DEF)) /* def of chan-name */ |
539 | { AST_setcur(u->n); |
540 | switch (t->step->n->ntyp) { |
541 | case ASGN: |
542 | AST_haschan(t->step->n->rgt); |
543 | break; |
544 | case 'r': |
545 | /* guess sends where name may originate */ |
546 | for (cl = chanlist; cl; cl = cl->nxt) /* all sends */ |
547 | { int aa = AST_nrpar(cl->s); |
548 | int bb = AST_nrpar(t->step->n); |
549 | if (aa != bb) /* matching nrs of params */ |
550 | continue; |
551 | |
552 | aa = AST_ord(cl->s, cl->n); |
553 | bb = AST_ord(t->step->n, u->n); |
554 | if (aa != bb) /* same position in parlist */ |
555 | continue; |
556 | |
557 | AST_add_alias(cl->n, 4); /* RCV assume possible match */ |
558 | } |
559 | break; |
560 | default: |
561 | printf("type = %d\n", t->step->n->ntyp); |
562 | non_fatal("unexpected chan def type", (char *) 0); |
563 | break; |
564 | } } |
565 | } |
566 | |
567 | static void |
568 | AST_aliases(void) |
569 | { ALIAS *na, *ca; |
570 | |
571 | for (na = chalias; na; na = na->nxt) |
572 | { printf("\npossible aliases of "); |
573 | AST_var(na->cnm, na->cnm->sym, 1); |
574 | printf("\n\t"); |
575 | for (ca = na->alias; ca; ca = ca->nxt) |
576 | { if (!ca->cnm->sym) |
577 | printf("no valid name "); |
578 | else |
579 | AST_var(ca->cnm, ca->cnm->sym, 1); |
580 | printf("<"); |
581 | if (ca->origin & 1) printf("RUN "); |
582 | if (ca->origin & 2) printf("ASGN "); |
583 | if (ca->origin & 4) printf("RCV "); |
584 | printf("[%s]", AST_isini(ca->cnm)?"Initzd":"Name"); |
585 | printf(">"); |
586 | if (ca->nxt) printf(", "); |
587 | } |
588 | printf("\n"); |
589 | } |
590 | printf("\n"); |
591 | } |
592 | |
593 | static void |
594 | AST_indirect(FSM_use *uin, FSM_trans *t, char *cause, char *pn) |
595 | { FSM_use *u; |
596 | |
597 | /* this is a newly discovered relevant statement */ |
598 | /* all vars it uses to contribute to its DEF are new criteria */ |
599 | |
600 | if (!(t->relevant&1)) AST_Changes++; |
601 | |
602 | t->round = AST_Round; |
603 | t->relevant = 1; |
604 | |
605 | if ((verbose&32) && t->step) |
606 | { printf("\tDR %s [[ ", pn); |
607 | comment(stdout, t->step->n, 0); |
608 | printf("]]\n\t\tfully relevant %s", cause); |
609 | if (uin) { printf(" due to "); AST_var(uin->n, uin->n->sym, 1); } |
610 | printf("\n"); |
611 | } |
612 | for (u = t->Val[0]; u; u = u->nxt) |
613 | if (u != uin |
614 | && (u->special&(USE|DEREF_USE))) |
615 | { if (verbose&32) |
616 | { printf("\t\t\tuses(%d): ", u->special); |
617 | AST_var(u->n, u->n->sym, 1); |
618 | printf("\n"); |
619 | } |
620 | name_AST_track(u->n, u->special); /* add to slice criteria */ |
621 | } |
622 | } |
623 | |
624 | static void |
625 | def_relevant(char *pn, FSM_trans *t, Lextok *n, int ischan) |
626 | { FSM_use *u; |
627 | ALIAS *na, *ca; |
628 | int chanref; |
629 | |
630 | /* look for all DEF's of n |
631 | * mark those stmnts relevant |
632 | * mark all var USEs in those stmnts as criteria |
633 | */ |
634 | |
635 | if (n->ntyp != ELSE) |
636 | for (u = t->Val[0]; u; u = u->nxt) |
637 | { chanref = (Sym_typ(u->n) == CHAN); |
638 | |
639 | if (ischan != chanref /* no possible match */ |
640 | || !(u->special&(DEF|DEREF_DEF))) /* not a def */ |
641 | continue; |
642 | |
643 | if (AST_mutual(u->n, n, 1)) |
644 | { AST_indirect(u, t, "(exact match)", pn); |
645 | continue; |
646 | } |
647 | |
648 | if (chanref) |
649 | for (na = chalias; na; na = na->nxt) |
650 | { if (!AST_mutual(u->n, na->cnm, 1)) |
651 | continue; |
652 | for (ca = na->alias; ca; ca = ca->nxt) |
653 | if (AST_mutual(ca->cnm, n, 1) |
654 | && AST_isini(ca->cnm)) |
655 | { AST_indirect(u, t, "(alias match)", pn); |
656 | break; |
657 | } |
658 | if (ca) break; |
659 | } } |
660 | } |
661 | |
662 | static void |
663 | AST_relevant(Lextok *n) |
664 | { AST *a; |
665 | FSM_state *f; |
666 | FSM_trans *t; |
667 | int ischan; |
668 | |
669 | /* look for all DEF's of n |
670 | * mark those stmnts relevant |
671 | * mark all var USEs in those stmnts as criteria |
672 | */ |
673 | |
674 | if (!n) return; |
675 | ischan = (Sym_typ(n) == CHAN); |
676 | |
677 | if (verbose&32) |
678 | { printf("<<ast_relevant (ntyp=%d) ", n->ntyp); |
679 | AST_var(n, n->sym, 1); |
680 | printf(">>\n"); |
681 | } |
682 | |
683 | for (t = expl_par; t; t = t->nxt) /* param assignments */ |
684 | { if (!(t->relevant&1)) |
685 | def_relevant(":params:", t, n, ischan); |
686 | } |
687 | |
688 | for (t = expl_var; t; t = t->nxt) |
689 | { if (!(t->relevant&1)) /* var inits */ |
690 | def_relevant(":vars:", t, n, ischan); |
691 | } |
692 | |
693 | for (a = ast; a; a = a->nxt) /* all other stmnts */ |
694 | { if (strcmp(a->p->n->name, ":never:") != 0 |
695 | && strcmp(a->p->n->name, ":trace:") != 0 |
696 | && strcmp(a->p->n->name, ":notrace:") != 0) |
697 | for (f = a->fsm; f; f = f->nxt) |
698 | for (t = f->t; t; t = t->nxt) |
699 | { if (!(t->relevant&1)) |
700 | def_relevant(a->p->n->name, t, n, ischan); |
701 | } } |
702 | } |
703 | |
704 | static int |
705 | AST_relpar(char *s) |
706 | { FSM_trans *t, *T; |
707 | FSM_use *u; |
708 | |
709 | for (T = expl_par; T; T = (T == expl_par)?expl_var: (FSM_trans *) 0) |
710 | for (t = T; t; t = t->nxt) |
711 | { if (t->relevant&1) |
712 | for (u = t->Val[0]; u; u = u->nxt) |
713 | { if (u->n->sym->type |
714 | && u->n->sym->context |
715 | && strcmp(u->n->sym->context->name, s) == 0) |
716 | { |
717 | if (verbose&32) |
718 | { printf("proctype %s relevant, due to symbol ", s); |
719 | AST_var(u->n, u->n->sym, 1); |
720 | printf("\n"); |
721 | } |
722 | return 1; |
723 | } } } |
724 | return 0; |
725 | } |
726 | |
727 | static void |
728 | AST_dorelevant(void) |
729 | { AST *a; |
730 | RPN *r; |
731 | |
732 | for (r = rpn; r; r = r->nxt) |
733 | { for (a = ast; a; a = a->nxt) |
734 | if (strcmp(a->p->n->name, r->rn->name) == 0) |
735 | { a->relevant |= 1; |
736 | break; |
737 | } |
738 | if (!a) |
739 | fatal("cannot find proctype %s", r->rn->name); |
740 | } |
741 | } |
742 | |
743 | static void |
744 | AST_procisrelevant(Symbol *s) |
745 | { RPN *r; |
746 | for (r = rpn; r; r = r->nxt) |
747 | if (strcmp(r->rn->name, s->name) == 0) |
748 | return; |
749 | r = (RPN *) emalloc(sizeof(RPN)); |
750 | r->rn = s; |
751 | r->nxt = rpn; |
752 | rpn = r; |
753 | } |
754 | |
755 | static int |
756 | AST_proc_isrel(char *s) |
757 | { AST *a; |
758 | |
759 | for (a = ast; a; a = a->nxt) |
760 | if (strcmp(a->p->n->name, s) == 0) |
761 | return (a->relevant&1); |
762 | non_fatal("cannot happen, missing proc in ast", (char *) 0); |
763 | return 0; |
764 | } |
765 | |
766 | static int |
767 | AST_scoutrun(Lextok *t) |
768 | { |
769 | if (!t) return 0; |
770 | |
771 | if (t->ntyp == RUN) |
772 | return AST_proc_isrel(t->sym->name); |
773 | return (AST_scoutrun(t->lft) || AST_scoutrun(t->rgt)); |
774 | } |
775 | |
776 | static void |
777 | AST_tagruns(void) |
778 | { AST *a; |
779 | FSM_state *f; |
780 | FSM_trans *t; |
781 | |
782 | /* if any stmnt inside a proctype is relevant |
783 | * or any parameter passed in a run |
784 | * then so are all the run statements on that proctype |
785 | */ |
786 | |
787 | for (a = ast; a; a = a->nxt) |
788 | { if (strcmp(a->p->n->name, ":never:") == 0 |
789 | || strcmp(a->p->n->name, ":trace:") == 0 |
790 | || strcmp(a->p->n->name, ":notrace:") == 0 |
791 | || strcmp(a->p->n->name, ":init:") == 0) |
792 | { a->relevant |= 1; /* the proctype is relevant */ |
793 | continue; |
794 | } |
795 | if (AST_relpar(a->p->n->name)) |
796 | a->relevant |= 1; |
797 | else |
798 | { for (f = a->fsm; f; f = f->nxt) |
799 | for (t = f->t; t; t = t->nxt) |
800 | if (t->relevant) |
801 | goto yes; |
802 | yes: if (f) |
803 | a->relevant |= 1; |
804 | } |
805 | } |
806 | |
807 | for (a = ast; a; a = a->nxt) |
808 | for (f = a->fsm; f; f = f->nxt) |
809 | for (t = f->t; t; t = t->nxt) |
810 | if (t->step |
811 | && AST_scoutrun(t->step->n)) |
812 | { AST_indirect((FSM_use *)0, t, ":run:", a->p->n->name); |
813 | /* BUT, not all actual params are relevant */ |
814 | } |
815 | } |
816 | |
817 | static void |
818 | AST_report(AST *a, Element *e) /* ALSO deduce irrelevant vars */ |
819 | { |
820 | if (!(a->relevant&2)) |
821 | { a->relevant |= 2; |
822 | printf("spin: redundant in proctype %s (for given property):\n", |
823 | a->p->n->name); |
824 | } |
825 | printf(" line %3d %s (state %d)", |
826 | e->n?e->n->ln:-1, |
827 | e->n?e->n->fn->name:"-", |
828 | e->seqno); |
829 | printf(" ["); |
830 | comment(stdout, e->n, 0); |
831 | printf("]\n"); |
832 | } |
833 | |
834 | static int |
835 | AST_always(Lextok *n) |
836 | { |
837 | if (!n) return 0; |
838 | |
839 | if (n->ntyp == '@' /* -end */ |
840 | || n->ntyp == 'p') /* remote reference */ |
841 | return 1; |
842 | return AST_always(n->lft) || AST_always(n->rgt); |
843 | } |
844 | |
845 | static void |
846 | AST_edge_dump(AST *a, FSM_state *f) |
847 | { FSM_trans *t; |
848 | FSM_use *u; |
849 | |
850 | for (t = f->t; t; t = t->nxt) /* edges */ |
851 | { |
852 | if (t->step && AST_always(t->step->n)) |
853 | t->relevant |= 1; /* always relevant */ |
854 | |
855 | if (verbose&32) |
856 | { switch (t->relevant) { |
857 | case 0: printf(" "); break; |
858 | case 1: printf("*%3d ", t->round); break; |
859 | case 2: printf("+%3d ", t->round); break; |
860 | case 3: printf("#%3d ", t->round); break; |
861 | default: printf("? "); break; |
862 | } |
863 | |
864 | printf("%d\t->\t%d\t", f->from, t->to); |
865 | if (t->step) |
866 | comment(stdout, t->step->n, 0); |
867 | else |
868 | printf("Unless"); |
869 | |
870 | for (u = t->Val[0]; u; u = u->nxt) |
871 | { printf(" <"); |
872 | AST_var(u->n, u->n->sym, 1); |
873 | printf(":%d>", u->special); |
874 | } |
875 | printf("\n"); |
876 | } else |
877 | { if (t->relevant) |
878 | continue; |
879 | |
880 | if (t->step) |
881 | switch(t->step->n->ntyp) { |
882 | case ASGN: |
883 | case 's': |
884 | case 'r': |
885 | case 'c': |
886 | if (t->step->n->lft->ntyp != CONST) |
887 | AST_report(a, t->step); |
888 | break; |
889 | |
890 | case PRINT: /* don't report */ |
891 | case PRINTM: |
892 | case ASSERT: |
893 | case C_CODE: |
894 | case C_EXPR: |
895 | default: |
896 | break; |
897 | } } } |
898 | } |
899 | |
900 | static void |
901 | AST_dfs(AST *a, int s, int vis) |
902 | { FSM_state *f; |
903 | FSM_trans *t; |
904 | |
905 | f = fsm_tbl[s]; |
906 | if (f->seen) return; |
907 | |
908 | f->seen = 1; |
909 | if (vis) AST_edge_dump(a, f); |
910 | |
911 | for (t = f->t; t; t = t->nxt) |
912 | AST_dfs(a, t->to, vis); |
913 | } |
914 | |
915 | static void |
916 | AST_dump(AST *a) |
917 | { FSM_state *f; |
918 | |
919 | for (f = a->fsm; f; f = f->nxt) |
920 | { f->seen = 0; |
921 | fsm_tbl[f->from] = f; |
922 | } |
923 | |
924 | if (verbose&32) |
925 | printf("AST_START %s from %d\n", a->p->n->name, a->i_st); |
926 | |
927 | AST_dfs(a, a->i_st, 1); |
928 | } |
929 | |
930 | static void |
931 | AST_sends(AST *a) |
932 | { FSM_state *f; |
933 | FSM_trans *t; |
934 | FSM_use *u; |
935 | ChanList *cl; |
936 | |
937 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
938 | for (t = f->t; t; t = t->nxt) /* transitions */ |
939 | { if (t->step |
940 | && t->step->n |
941 | && t->step->n->ntyp == 's') |
942 | for (u = t->Val[0]; u; u = u->nxt) |
943 | { if (Sym_typ(u->n) == CHAN |
944 | && ((u->special&USE) && !(u->special&DEREF_USE))) |
945 | { |
946 | #if 0 |
947 | printf("%s -- (%d->%d) -- ", |
948 | a->p->n->name, f->from, t->to); |
949 | AST_var(u->n, u->n->sym, 1); |
950 | printf(" -> chanlist\n"); |
951 | #endif |
952 | cl = (ChanList *) emalloc(sizeof(ChanList)); |
953 | cl->s = t->step->n; |
954 | cl->n = u->n; |
955 | cl->nxt = chanlist; |
956 | chanlist = cl; |
957 | } } } } |
958 | |
959 | static ALIAS * |
960 | AST_alfind(Lextok *n) |
961 | { ALIAS *na; |
962 | |
963 | for (na = chalias; na; na = na->nxt) |
964 | if (AST_mutual(na->cnm, n, 1)) |
965 | return na; |
966 | return (ALIAS *) 0; |
967 | } |
968 | |
969 | static void |
970 | AST_trans(void) |
971 | { ALIAS *na, *ca, *da, *ea; |
972 | int nchanges; |
973 | |
974 | do { |
975 | nchanges = 0; |
976 | for (na = chalias; na; na = na->nxt) |
977 | { chalcur = na; |
978 | for (ca = na->alias; ca; ca = ca->nxt) |
979 | { da = AST_alfind(ca->cnm); |
980 | if (da) |
981 | for (ea = da->alias; ea; ea = ea->nxt) |
982 | { nchanges += AST_add_alias(ea->cnm, |
983 | ea->origin|ca->origin); |
984 | } } } |
985 | } while (nchanges > 0); |
986 | |
987 | chalcur = (ALIAS *) 0; |
988 | } |
989 | |
990 | static void |
991 | AST_def_use(AST *a) |
992 | { FSM_state *f; |
993 | FSM_trans *t; |
994 | |
995 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
996 | for (t = f->t; t; t = t->nxt) /* all edges */ |
997 | { cur_t = t; |
998 | rel_use(t->Val[0]); /* redo Val; doesn't cover structs */ |
999 | rel_use(t->Val[1]); |
1000 | t->Val[0] = t->Val[1] = (FSM_use *) 0; |
1001 | |
1002 | if (!t->step) continue; |
1003 | |
1004 | def_use(t->step->n, 0); /* def/use info, including structs */ |
1005 | } |
1006 | cur_t = (FSM_trans *) 0; |
1007 | } |
1008 | |
1009 | static void |
1010 | name_AST_track(Lextok *n, int code) |
1011 | { extern int nr_errs; |
1012 | #if 0 |
1013 | printf("AST_name: "); |
1014 | AST_var(n, n->sym, 1); |
1015 | printf(" -- %d\n", code); |
1016 | #endif |
1017 | if (in_recv && (code&DEF) && (code&USE)) |
1018 | { printf("spin: error: DEF and USE of same var in rcv stmnt: "); |
1019 | AST_var(n, n->sym, 1); |
1020 | printf(" -- %d\n", code); |
1021 | nr_errs++; |
1022 | } |
1023 | check_slice(n, code); |
1024 | } |
1025 | |
1026 | void |
1027 | AST_track(Lextok *now, int code) /* called from main.c */ |
1028 | { Lextok *v; extern int export_ast; |
1029 | |
1030 | if (!export_ast) return; |
1031 | |
1032 | if (now) |
1033 | switch (now->ntyp) { |
1034 | case LEN: |
1035 | case FULL: |
1036 | case EMPTY: |
1037 | case NFULL: |
1038 | case NEMPTY: |
1039 | AST_track(now->lft, DEREF_USE|USE|code); |
1040 | break; |
1041 | |
1042 | case '/': |
1043 | case '*': |
1044 | case '-': |
1045 | case '+': |
1046 | case '%': |
1047 | case '&': |
1048 | case '^': |
1049 | case '|': |
1050 | case LE: |
1051 | case GE: |
1052 | case GT: |
1053 | case LT: |
1054 | case NE: |
1055 | case EQ: |
1056 | case OR: |
1057 | case AND: |
1058 | case LSHIFT: |
1059 | case RSHIFT: |
1060 | AST_track(now->rgt, USE|code); |
1061 | /* fall through */ |
1062 | case '!': |
1063 | case UMIN: |
1064 | case '~': |
1065 | case 'c': |
1066 | case ENABLED: |
1067 | case ASSERT: |
1068 | AST_track(now->lft, USE|code); |
1069 | break; |
1070 | |
1071 | case EVAL: |
1072 | AST_track(now->lft, USE|(code&(~DEF))); |
1073 | break; |
1074 | |
1075 | case NAME: |
1076 | name_AST_track(now, code); |
1077 | if (now->sym->nel != 1) |
1078 | AST_track(now->lft, USE|code); /* index */ |
1079 | break; |
1080 | |
1081 | case 'R': |
1082 | AST_track(now->lft, DEREF_USE|USE|code); |
1083 | for (v = now->rgt; v; v = v->rgt) |
1084 | AST_track(v->lft, code); /* a deeper eval can add USE */ |
1085 | break; |
1086 | |
1087 | case '?': |
1088 | AST_track(now->lft, USE|code); |
1089 | if (now->rgt) |
1090 | { AST_track(now->rgt->lft, code); |
1091 | AST_track(now->rgt->rgt, code); |
1092 | } |
1093 | break; |
1094 | |
1095 | /* added for control deps: */ |
1096 | case TYPE: |
1097 | name_AST_track(now, code); |
1098 | break; |
1099 | case ASGN: |
1100 | AST_track(now->lft, DEF|code); |
1101 | AST_track(now->rgt, USE|code); |
1102 | break; |
1103 | case RUN: |
1104 | name_AST_track(now, USE); |
1105 | for (v = now->lft; v; v = v->rgt) |
1106 | AST_track(v->lft, USE|code); |
1107 | break; |
1108 | case 's': |
1109 | AST_track(now->lft, DEREF_DEF|DEREF_USE|USE|code); |
1110 | for (v = now->rgt; v; v = v->rgt) |
1111 | AST_track(v->lft, USE|code); |
1112 | break; |
1113 | case 'r': |
1114 | AST_track(now->lft, DEREF_DEF|DEREF_USE|USE|code); |
1115 | for (v = now->rgt; v; v = v->rgt) |
1116 | { in_recv++; |
1117 | AST_track(v->lft, DEF|code); |
1118 | in_recv--; |
1119 | } |
1120 | break; |
1121 | case PRINT: |
1122 | for (v = now->lft; v; v = v->rgt) |
1123 | AST_track(v->lft, USE|code); |
1124 | break; |
1125 | case PRINTM: |
1126 | AST_track(now->lft, USE); |
1127 | break; |
1128 | /* end add */ |
1129 | case 'p': |
1130 | #if 0 |
1131 | 'p' -sym-> _p |
1132 | / |
1133 | '?' -sym-> a (proctype) |
1134 | / |
1135 | b (pid expr) |
1136 | #endif |
1137 | AST_track(now->lft->lft, USE|code); |
1138 | AST_procisrelevant(now->lft->sym); |
1139 | break; |
1140 | |
1141 | case CONST: |
1142 | case ELSE: |
1143 | case NONPROGRESS: |
1144 | case PC_VAL: |
1145 | case 'q': |
1146 | break; |
1147 | |
1148 | case '.': |
1149 | case GOTO: |
1150 | case BREAK: |
1151 | case '@': |
1152 | case D_STEP: |
1153 | case ATOMIC: |
1154 | case NON_ATOMIC: |
1155 | case IF: |
1156 | case DO: |
1157 | case UNLESS: |
1158 | case TIMEOUT: |
1159 | case C_CODE: |
1160 | case C_EXPR: |
1161 | break; |
1162 | |
1163 | default: |
1164 | printf("AST_track, NOT EXPECTED ntyp: %d\n", now->ntyp); |
1165 | break; |
1166 | } |
1167 | } |
1168 | |
1169 | static int |
1170 | AST_dump_rel(void) |
1171 | { Slicer *rv; |
1172 | Ordered *walk; |
1173 | char buf[64]; |
1174 | int banner=0; |
1175 | |
1176 | if (verbose&32) |
1177 | { printf("Relevant variables:\n"); |
1178 | for (rv = rel_vars; rv; rv = rv->nxt) |
1179 | { printf("\t"); |
1180 | AST_var(rv->n, rv->n->sym, 1); |
1181 | printf("\n"); |
1182 | } |
1183 | return 1; |
1184 | } |
1185 | for (rv = rel_vars; rv; rv = rv->nxt) |
1186 | rv->n->sym->setat = 1; /* mark it */ |
1187 | |
1188 | for (walk = all_names; walk; walk = walk->next) |
1189 | { Symbol *s; |
1190 | s = walk->entry; |
1191 | if (!s->setat |
1192 | && (s->type != MTYPE || s->ini->ntyp != CONST) |
1193 | && s->type != STRUCT /* report only fields */ |
1194 | && s->type != PROCTYPE |
1195 | && !s->owner |
1196 | && sputtype(buf, s->type)) |
1197 | { if (!banner) |
1198 | { banner = 1; |
1199 | printf("spin: redundant vars (for given property):\n"); |
1200 | } |
1201 | printf("\t"); |
1202 | symvar(s); |
1203 | } } |
1204 | return banner; |
1205 | } |
1206 | |
1207 | static void |
1208 | AST_suggestions(void) |
1209 | { Symbol *s; |
1210 | Ordered *walk; |
1211 | FSM_state *f; |
1212 | FSM_trans *t; |
1213 | AST *a; |
1214 | int banner=0; |
1215 | int talked=0; |
1216 | |
1217 | for (walk = all_names; walk; walk = walk->next) |
1218 | { s = walk->entry; |
1219 | if (s->colnr == 2 /* only used in conditionals */ |
1220 | && (s->type == BYTE |
1221 | || s->type == SHORT |
1222 | || s->type == INT |
1223 | || s->type == MTYPE)) |
1224 | { if (!banner) |
1225 | { banner = 1; |
1226 | printf("spin: consider using predicate"); |
1227 | printf(" abstraction to replace:\n"); |
1228 | } |
1229 | printf("\t"); |
1230 | symvar(s); |
1231 | } } |
1232 | |
1233 | /* look for source and sink processes */ |
1234 | |
1235 | for (a = ast; a; a = a->nxt) /* automata */ |
1236 | { banner = 0; |
1237 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
1238 | for (t = f->t; t; t = t->nxt) /* transitions */ |
1239 | { if (t->step) |
1240 | switch (t->step->n->ntyp) { |
1241 | case 's': |
1242 | banner |= 1; |
1243 | break; |
1244 | case 'r': |
1245 | banner |= 2; |
1246 | break; |
1247 | case '.': |
1248 | case D_STEP: |
1249 | case ATOMIC: |
1250 | case NON_ATOMIC: |
1251 | case IF: |
1252 | case DO: |
1253 | case UNLESS: |
1254 | case '@': |
1255 | case GOTO: |
1256 | case BREAK: |
1257 | case PRINT: |
1258 | case PRINTM: |
1259 | case ASSERT: |
1260 | case C_CODE: |
1261 | case C_EXPR: |
1262 | break; |
1263 | default: |
1264 | banner |= 4; |
1265 | goto no_good; |
1266 | } |
1267 | } |
1268 | no_good: if (banner == 1 || banner == 2) |
1269 | { printf("spin: proctype %s defines a %s process\n", |
1270 | a->p->n->name, |
1271 | banner==1?"source":"sink"); |
1272 | talked |= banner; |
1273 | } else if (banner == 3) |
1274 | { printf("spin: proctype %s mimics a buffer\n", |
1275 | a->p->n->name); |
1276 | talked |= 4; |
1277 | } |
1278 | } |
1279 | if (talked&1) |
1280 | { printf("\tto reduce complexity, consider merging the code of\n"); |
1281 | printf("\teach source process into the code of its target\n"); |
1282 | } |
1283 | if (talked&2) |
1284 | { printf("\tto reduce complexity, consider merging the code of\n"); |
1285 | printf("\teach sink process into the code of its source\n"); |
1286 | } |
1287 | if (talked&4) |
1288 | printf("\tto reduce complexity, avoid buffer processes\n"); |
1289 | } |
1290 | |
1291 | static void |
1292 | AST_preserve(void) |
1293 | { Slicer *sc, *nx, *rv; |
1294 | |
1295 | for (sc = slicer; sc; sc = nx) |
1296 | { if (!sc->used) |
1297 | break; /* done */ |
1298 | |
1299 | nx = sc->nxt; |
1300 | |
1301 | for (rv = rel_vars; rv; rv = rv->nxt) |
1302 | if (AST_mutual(sc->n, rv->n, 1)) |
1303 | break; |
1304 | |
1305 | if (!rv) /* not already there */ |
1306 | { sc->nxt = rel_vars; |
1307 | rel_vars = sc; |
1308 | } } |
1309 | slicer = sc; |
1310 | } |
1311 | |
1312 | static void |
1313 | check_slice(Lextok *n, int code) |
1314 | { Slicer *sc; |
1315 | |
1316 | for (sc = slicer; sc; sc = sc->nxt) |
1317 | if (AST_mutual(sc->n, n, 1) |
1318 | && sc->code == code) |
1319 | return; /* already there */ |
1320 | |
1321 | sc = (Slicer *) emalloc(sizeof(Slicer)); |
1322 | sc->n = n; |
1323 | |
1324 | sc->code = code; |
1325 | sc->used = 0; |
1326 | sc->nxt = slicer; |
1327 | slicer = sc; |
1328 | } |
1329 | |
1330 | static void |
1331 | AST_data_dep(void) |
1332 | { Slicer *sc; |
1333 | |
1334 | /* mark all def-relevant transitions */ |
1335 | for (sc = slicer; sc; sc = sc->nxt) |
1336 | { sc->used = 1; |
1337 | if (verbose&32) |
1338 | { printf("spin: slice criterion "); |
1339 | AST_var(sc->n, sc->n->sym, 1); |
1340 | printf(" type=%d\n", Sym_typ(sc->n)); |
1341 | } |
1342 | AST_relevant(sc->n); |
1343 | } |
1344 | AST_tagruns(); /* mark 'run's relevant if target proctype is relevant */ |
1345 | } |
1346 | |
1347 | static int |
1348 | AST_blockable(AST *a, int s) |
1349 | { FSM_state *f; |
1350 | FSM_trans *t; |
1351 | |
1352 | f = fsm_tbl[s]; |
1353 | |
1354 | for (t = f->t; t; t = t->nxt) |
1355 | { if (t->relevant&2) |
1356 | return 1; |
1357 | |
1358 | if (t->step && t->step->n) |
1359 | switch (t->step->n->ntyp) { |
1360 | case IF: |
1361 | case DO: |
1362 | case ATOMIC: |
1363 | case NON_ATOMIC: |
1364 | case D_STEP: |
1365 | if (AST_blockable(a, t->to)) |
1366 | { t->round = AST_Round; |
1367 | t->relevant |= 2; |
1368 | return 1; |
1369 | } |
1370 | /* else fall through */ |
1371 | default: |
1372 | break; |
1373 | } |
1374 | else if (AST_blockable(a, t->to)) /* Unless */ |
1375 | { t->round = AST_Round; |
1376 | t->relevant |= 2; |
1377 | return 1; |
1378 | } |
1379 | } |
1380 | return 0; |
1381 | } |
1382 | |
1383 | static void |
1384 | AST_spread(AST *a, int s) |
1385 | { FSM_state *f; |
1386 | FSM_trans *t; |
1387 | |
1388 | f = fsm_tbl[s]; |
1389 | |
1390 | for (t = f->t; t; t = t->nxt) |
1391 | { if (t->relevant&2) |
1392 | continue; |
1393 | |
1394 | if (t->step && t->step->n) |
1395 | switch (t->step->n->ntyp) { |
1396 | case IF: |
1397 | case DO: |
1398 | case ATOMIC: |
1399 | case NON_ATOMIC: |
1400 | case D_STEP: |
1401 | AST_spread(a, t->to); |
1402 | /* fall thru */ |
1403 | default: |
1404 | t->round = AST_Round; |
1405 | t->relevant |= 2; |
1406 | break; |
1407 | } |
1408 | else /* Unless */ |
1409 | { AST_spread(a, t->to); |
1410 | t->round = AST_Round; |
1411 | t->relevant |= 2; |
1412 | } |
1413 | } |
1414 | } |
1415 | |
1416 | static int |
1417 | AST_notrelevant(Lextok *n) |
1418 | { Slicer *s; |
1419 | |
1420 | for (s = rel_vars; s; s = s->nxt) |
1421 | if (AST_mutual(s->n, n, 1)) |
1422 | return 0; |
1423 | for (s = slicer; s; s = s->nxt) |
1424 | if (AST_mutual(s->n, n, 1)) |
1425 | return 0; |
1426 | return 1; |
1427 | } |
1428 | |
1429 | static int |
1430 | AST_withchan(Lextok *n) |
1431 | { |
1432 | if (!n) return 0; |
1433 | if (Sym_typ(n) == CHAN) |
1434 | return 1; |
1435 | return AST_withchan(n->lft) || AST_withchan(n->rgt); |
1436 | } |
1437 | |
1438 | static int |
1439 | AST_suspect(FSM_trans *t) |
1440 | { FSM_use *u; |
1441 | /* check for possible overkill */ |
1442 | if (!t || !t->step || !AST_withchan(t->step->n)) |
1443 | return 0; |
1444 | for (u = t->Val[0]; u; u = u->nxt) |
1445 | if (AST_notrelevant(u->n)) |
1446 | return 1; |
1447 | return 0; |
1448 | } |
1449 | |
1450 | static void |
1451 | AST_shouldconsider(AST *a, int s) |
1452 | { FSM_state *f; |
1453 | FSM_trans *t; |
1454 | |
1455 | f = fsm_tbl[s]; |
1456 | for (t = f->t; t; t = t->nxt) |
1457 | { if (t->step && t->step->n) |
1458 | switch (t->step->n->ntyp) { |
1459 | case IF: |
1460 | case DO: |
1461 | case ATOMIC: |
1462 | case NON_ATOMIC: |
1463 | case D_STEP: |
1464 | AST_shouldconsider(a, t->to); |
1465 | break; |
1466 | default: |
1467 | AST_track(t->step->n, 0); |
1468 | /* |
1469 | AST_track is called here for a blockable stmnt from which |
1470 | a relevant stmnmt was shown to be reachable |
1471 | for a condition this makes all USEs relevant |
1472 | but for a channel operation it only makes the executability |
1473 | relevant -- in those cases, parameters that aren't already |
1474 | relevant may be replaceable with arbitrary tokens |
1475 | */ |
1476 | if (AST_suspect(t)) |
1477 | { printf("spin: possibly redundant parameters in: "); |
1478 | comment(stdout, t->step->n, 0); |
1479 | printf("\n"); |
1480 | } |
1481 | break; |
1482 | } |
1483 | else /* an Unless */ |
1484 | AST_shouldconsider(a, t->to); |
1485 | } |
1486 | } |
1487 | |
1488 | static int |
1489 | FSM_critical(AST *a, int s) |
1490 | { FSM_state *f; |
1491 | FSM_trans *t; |
1492 | |
1493 | /* is a 1-relevant stmnt reachable from this state? */ |
1494 | |
1495 | f = fsm_tbl[s]; |
1496 | if (f->seen) |
1497 | goto done; |
1498 | f->seen = 1; |
1499 | f->cr = 0; |
1500 | for (t = f->t; t; t = t->nxt) |
1501 | if ((t->relevant&1) |
1502 | || FSM_critical(a, t->to)) |
1503 | { f->cr = 1; |
1504 | |
1505 | if (verbose&32) |
1506 | { printf("\t\t\t\tcritical(%d) ", t->relevant); |
1507 | comment(stdout, t->step->n, 0); |
1508 | printf("\n"); |
1509 | } |
1510 | break; |
1511 | } |
1512 | #if 0 |
1513 | else { |
1514 | if (verbose&32) |
1515 | { printf("\t\t\t\tnot-crit "); |
1516 | comment(stdout, t->step->n, 0); |
1517 | printf("\n"); |
1518 | } |
1519 | } |
1520 | #endif |
1521 | done: |
1522 | return f->cr; |
1523 | } |
1524 | |
1525 | static void |
1526 | AST_ctrl(AST *a) |
1527 | { FSM_state *f; |
1528 | FSM_trans *t; |
1529 | int hit; |
1530 | |
1531 | /* add all blockable transitions |
1532 | * from which relevant transitions can be reached |
1533 | */ |
1534 | if (verbose&32) |
1535 | printf("CTL -- %s\n", a->p->n->name); |
1536 | |
1537 | /* 1 : mark all blockable edges */ |
1538 | for (f = a->fsm; f; f = f->nxt) |
1539 | { if (!(f->scratch&2)) /* not part of irrelevant subgraph */ |
1540 | for (t = f->t; t; t = t->nxt) |
1541 | { if (t->step && t->step->n) |
1542 | switch (t->step->n->ntyp) { |
1543 | case 'r': |
1544 | case 's': |
1545 | case 'c': |
1546 | case ELSE: |
1547 | t->round = AST_Round; |
1548 | t->relevant |= 2; /* mark for next phases */ |
1549 | if (verbose&32) |
1550 | { printf("\tpremark "); |
1551 | comment(stdout, t->step->n, 0); |
1552 | printf("\n"); |
1553 | } |
1554 | break; |
1555 | default: |
1556 | break; |
1557 | } } } |
1558 | |
1559 | /* 2: keep only 2-marked stmnts from which 1-marked stmnts can be reached */ |
1560 | for (f = a->fsm; f; f = f->nxt) |
1561 | { fsm_tbl[f->from] = f; |
1562 | f->seen = 0; /* used in dfs from FSM_critical */ |
1563 | } |
1564 | for (f = a->fsm; f; f = f->nxt) |
1565 | { if (!FSM_critical(a, f->from)) |
1566 | for (t = f->t; t; t = t->nxt) |
1567 | if (t->relevant&2) |
1568 | { t->relevant &= ~2; /* clear mark */ |
1569 | if (verbose&32) |
1570 | { printf("\t\tnomark "); |
1571 | if (t->step && t->step->n) |
1572 | comment(stdout, t->step->n, 0); |
1573 | printf("\n"); |
1574 | } } } |
1575 | |
1576 | /* 3 : lift marks across IF/DO etc. */ |
1577 | for (f = a->fsm; f; f = f->nxt) |
1578 | { hit = 0; |
1579 | for (t = f->t; t; t = t->nxt) |
1580 | { if (t->step && t->step->n) |
1581 | switch (t->step->n->ntyp) { |
1582 | case IF: |
1583 | case DO: |
1584 | case ATOMIC: |
1585 | case NON_ATOMIC: |
1586 | case D_STEP: |
1587 | if (AST_blockable(a, t->to)) |
1588 | hit = 1; |
1589 | break; |
1590 | default: |
1591 | break; |
1592 | } |
1593 | else if (AST_blockable(a, t->to)) /* Unless */ |
1594 | hit = 1; |
1595 | |
1596 | if (hit) break; |
1597 | } |
1598 | if (hit) /* at least one outgoing trans can block */ |
1599 | for (t = f->t; t; t = t->nxt) |
1600 | { t->round = AST_Round; |
1601 | t->relevant |= 2; /* lift */ |
1602 | if (verbose&32) |
1603 | { printf("\t\t\tliftmark "); |
1604 | if (t->step && t->step->n) |
1605 | comment(stdout, t->step->n, 0); |
1606 | printf("\n"); |
1607 | } |
1608 | AST_spread(a, t->to); /* and spread to all guards */ |
1609 | } } |
1610 | |
1611 | /* 4: nodes with 2-marked out-edges contribute new slice criteria */ |
1612 | for (f = a->fsm; f; f = f->nxt) |
1613 | for (t = f->t; t; t = t->nxt) |
1614 | if (t->relevant&2) |
1615 | { AST_shouldconsider(a, f->from); |
1616 | break; /* inner loop */ |
1617 | } |
1618 | } |
1619 | |
1620 | static void |
1621 | AST_control_dep(void) |
1622 | { AST *a; |
1623 | |
1624 | for (a = ast; a; a = a->nxt) |
1625 | if (strcmp(a->p->n->name, ":never:") != 0 |
1626 | && strcmp(a->p->n->name, ":trace:") != 0 |
1627 | && strcmp(a->p->n->name, ":notrace:") != 0) |
1628 | AST_ctrl(a); |
1629 | } |
1630 | |
1631 | static void |
1632 | AST_prelabel(void) |
1633 | { AST *a; |
1634 | FSM_state *f; |
1635 | FSM_trans *t; |
1636 | |
1637 | for (a = ast; a; a = a->nxt) |
1638 | { if (strcmp(a->p->n->name, ":never:") != 0 |
1639 | && strcmp(a->p->n->name, ":trace:") != 0 |
1640 | && strcmp(a->p->n->name, ":notrace:") != 0) |
1641 | for (f = a->fsm; f; f = f->nxt) |
1642 | for (t = f->t; t; t = t->nxt) |
1643 | { if (t->step |
1644 | && t->step->n |
1645 | && t->step->n->ntyp == ASSERT |
1646 | ) |
1647 | { t->relevant |= 1; |
1648 | } } } |
1649 | } |
1650 | |
1651 | static void |
1652 | AST_criteria(void) |
1653 | { /* |
1654 | * remote labels are handled separately -- by making |
1655 | * sure they are not pruned away during optimization |
1656 | */ |
1657 | AST_Changes = 1; /* to get started */ |
1658 | for (AST_Round = 1; slicer && AST_Changes; AST_Round++) |
1659 | { AST_Changes = 0; |
1660 | AST_data_dep(); |
1661 | AST_preserve(); /* moves processed vars from slicer to rel_vars */ |
1662 | AST_dominant(); /* mark data-irrelevant subgraphs */ |
1663 | AST_control_dep(); /* can add data deps, which add control deps */ |
1664 | |
1665 | if (verbose&32) |
1666 | printf("\n\nROUND %d -- changes %d\n", |
1667 | AST_Round, AST_Changes); |
1668 | } |
1669 | } |
1670 | |
1671 | static void |
1672 | AST_alias_analysis(void) /* aliasing of promela channels */ |
1673 | { AST *a; |
1674 | |
1675 | for (a = ast; a; a = a->nxt) |
1676 | AST_sends(a); /* collect chan-names that are send across chans */ |
1677 | |
1678 | for (a = ast; a; a = a->nxt) |
1679 | AST_para(a->p); /* aliasing of chans thru proctype parameters */ |
1680 | |
1681 | for (a = ast; a; a = a->nxt) |
1682 | AST_other(a); /* chan params in asgns and recvs */ |
1683 | |
1684 | AST_trans(); /* transitive closure of alias table */ |
1685 | |
1686 | if (verbose&32) |
1687 | AST_aliases(); /* show channel aliasing info */ |
1688 | } |
1689 | |
1690 | void |
1691 | AST_slice(void) |
1692 | { AST *a; |
1693 | int spurious = 0; |
1694 | |
1695 | if (!slicer) |
1696 | { non_fatal("no slice criteria (or no claim) specified", |
1697 | (char *) 0); |
1698 | spurious = 1; |
1699 | } |
1700 | AST_dorelevant(); /* mark procs refered to in remote refs */ |
1701 | |
1702 | for (a = ast; a; a = a->nxt) |
1703 | AST_def_use(a); /* compute standard def/use information */ |
1704 | |
1705 | AST_hidden(); /* parameter passing and local var inits */ |
1706 | |
1707 | AST_alias_analysis(); /* channel alias analysis */ |
1708 | |
1709 | AST_prelabel(); /* mark all 'assert(...)' stmnts as relevant */ |
1710 | AST_criteria(); /* process the slice criteria from |
1711 | * asserts and from the never claim |
1712 | */ |
1713 | if (!spurious || (verbose&32)) |
1714 | { spurious = 1; |
1715 | for (a = ast; a; a = a->nxt) |
1716 | { AST_dump(a); /* marked up result */ |
1717 | if (a->relevant&2) /* it printed something */ |
1718 | spurious = 0; |
1719 | } |
1720 | if (!AST_dump_rel() /* relevant variables */ |
1721 | && spurious) |
1722 | printf("spin: no redundancies found (for given property)\n"); |
1723 | } |
1724 | AST_suggestions(); |
1725 | |
1726 | if (verbose&32) |
1727 | show_expl(); |
1728 | } |
1729 | |
1730 | void |
1731 | AST_store(ProcList *p, int start_state) |
1732 | { AST *n_ast; |
1733 | |
1734 | if (strcmp(p->n->name, ":never:") != 0 |
1735 | && strcmp(p->n->name, ":trace:") != 0 |
1736 | && strcmp(p->n->name, ":notrace:") != 0) |
1737 | { n_ast = (AST *) emalloc(sizeof(AST)); |
1738 | n_ast->p = p; |
1739 | n_ast->i_st = start_state; |
1740 | n_ast->relevant = 0; |
1741 | n_ast->fsm = fsm; |
1742 | n_ast->nxt = ast; |
1743 | ast = n_ast; |
1744 | } |
1745 | fsm = (FSM_state *) 0; /* hide it from FSM_DEL */ |
1746 | } |
1747 | |
1748 | static void |
1749 | AST_add_explicit(Lextok *d, Lextok *u) |
1750 | { FSM_trans *e = (FSM_trans *) emalloc(sizeof(FSM_trans)); |
1751 | |
1752 | e->to = 0; /* or start_state ? */ |
1753 | e->relevant = 0; /* to be determined */ |
1754 | e->step = (Element *) 0; /* left blank */ |
1755 | e->Val[0] = e->Val[1] = (FSM_use *) 0; |
1756 | |
1757 | cur_t = e; |
1758 | |
1759 | def_use(u, USE); |
1760 | def_use(d, DEF); |
1761 | |
1762 | cur_t = (FSM_trans *) 0; |
1763 | |
1764 | e->nxt = explicit; |
1765 | explicit = e; |
1766 | } |
1767 | |
1768 | static void |
1769 | AST_fp1(char *s, Lextok *t, Lextok *f, int parno) |
1770 | { Lextok *v; |
1771 | int cnt; |
1772 | |
1773 | if (!t) return; |
1774 | |
1775 | if (t->ntyp == RUN) |
1776 | { if (strcmp(t->sym->name, s) == 0) |
1777 | for (v = t->lft, cnt = 1; v; v = v->rgt, cnt++) |
1778 | if (cnt == parno) |
1779 | { AST_add_explicit(f, v->lft); |
1780 | break; |
1781 | } |
1782 | } else |
1783 | { AST_fp1(s, t->lft, f, parno); |
1784 | AST_fp1(s, t->rgt, f, parno); |
1785 | } |
1786 | } |
1787 | |
1788 | static void |
1789 | AST_mk1(char *s, Lextok *c, int parno) |
1790 | { AST *a; |
1791 | FSM_state *f; |
1792 | FSM_trans *t; |
1793 | |
1794 | /* concoct an extra FSM_trans *t with the asgn of |
1795 | * formal par c to matching actual pars made explicit |
1796 | */ |
1797 | |
1798 | for (a = ast; a; a = a->nxt) /* automata */ |
1799 | for (f = a->fsm; f; f = f->nxt) /* control states */ |
1800 | for (t = f->t; t; t = t->nxt) /* transitions */ |
1801 | { if (t->step) |
1802 | AST_fp1(s, t->step->n, c, parno); |
1803 | } |
1804 | } |
1805 | |
1806 | static void |
1807 | AST_par_init(void) /* parameter passing -- hidden assignments */ |
1808 | { AST *a; |
1809 | Lextok *f, *t, *c; |
1810 | int cnt; |
1811 | |
1812 | for (a = ast; a; a = a->nxt) |
1813 | { if (strcmp(a->p->n->name, ":never:") == 0 |
1814 | || strcmp(a->p->n->name, ":trace:") == 0 |
1815 | || strcmp(a->p->n->name, ":notrace:") == 0 |
1816 | || strcmp(a->p->n->name, ":init:") == 0) |
1817 | continue; /* have no params */ |
1818 | |
1819 | cnt = 0; |
1820 | for (f = a->p->p; f; f = f->rgt) /* types */ |
1821 | for (t = f->lft; t; t = t->rgt) /* formals */ |
1822 | { cnt++; /* formal par count */ |
1823 | c = (t->ntyp != ',')? t : t->lft; /* the formal parameter */ |
1824 | AST_mk1(a->p->n->name, c, cnt); /* all matching run statements */ |
1825 | } } |
1826 | } |
1827 | |
1828 | static void |
1829 | AST_var_init(void) /* initialized vars (not chans) - hidden assignments */ |
1830 | { Ordered *walk; |
1831 | Lextok *x; |
1832 | Symbol *sp; |
1833 | AST *a; |
1834 | |
1835 | for (walk = all_names; walk; walk = walk->next) |
1836 | { sp = walk->entry; |
1837 | if (sp |
1838 | && !sp->context /* globals */ |
1839 | && sp->type != PROCTYPE |
1840 | && sp->ini |
1841 | && (sp->type != MTYPE || sp->ini->ntyp != CONST) /* not mtype defs */ |
1842 | && sp->ini->ntyp != CHAN) |
1843 | { x = nn(ZN, TYPE, ZN, ZN); |
1844 | x->sym = sp; |
1845 | AST_add_explicit(x, sp->ini); |
1846 | } } |
1847 | |
1848 | for (a = ast; a; a = a->nxt) |
1849 | { if (strcmp(a->p->n->name, ":never:") != 0 |
1850 | && strcmp(a->p->n->name, ":trace:") != 0 |
1851 | && strcmp(a->p->n->name, ":notrace:") != 0) /* claim has no locals */ |
1852 | for (walk = all_names; walk; walk = walk->next) |
1853 | { sp = walk->entry; |
1854 | if (sp |
1855 | && sp->context |
1856 | && strcmp(sp->context->name, a->p->n->name) == 0 |
1857 | && sp->Nid >= 0 /* not a param */ |
1858 | && sp->type != LABEL |
1859 | && sp->ini |
1860 | && sp->ini->ntyp != CHAN) |
1861 | { x = nn(ZN, TYPE, ZN, ZN); |
1862 | x->sym = sp; |
1863 | AST_add_explicit(x, sp->ini); |
1864 | } } } |
1865 | } |
1866 | |
1867 | static void |
1868 | show_expl(void) |
1869 | { FSM_trans *t, *T; |
1870 | FSM_use *u; |
1871 | |
1872 | printf("\nExplicit List:\n"); |
1873 | for (T = expl_par; T; T = (T == expl_par)?expl_var: (FSM_trans *) 0) |
1874 | { for (t = T; t; t = t->nxt) |
1875 | { if (!t->Val[0]) continue; |
1876 | printf("%s", t->relevant?"*":" "); |
1877 | printf("%3d", t->round); |
1878 | for (u = t->Val[0]; u; u = u->nxt) |
1879 | { printf("\t<"); |
1880 | AST_var(u->n, u->n->sym, 1); |
1881 | printf(":%d>, ", u->special); |
1882 | } |
1883 | printf("\n"); |
1884 | } |
1885 | printf("==\n"); |
1886 | } |
1887 | printf("End\n"); |
1888 | } |
1889 | |
1890 | static void |
1891 | AST_hidden(void) /* reveal all hidden assignments */ |
1892 | { |
1893 | AST_par_init(); |
1894 | expl_par = explicit; |
1895 | explicit = (FSM_trans *) 0; |
1896 | |
1897 | AST_var_init(); |
1898 | expl_var = explicit; |
1899 | explicit = (FSM_trans *) 0; |
1900 | } |
1901 | |
1902 | #define BPW (8*sizeof(ulong)) /* bits per word */ |
1903 | |
1904 | static int |
1905 | bad_scratch(FSM_state *f, int upto) |
1906 | { FSM_trans *t; |
1907 | #if 0 |
1908 | 1. all internal branch-points have else-s |
1909 | 2. all non-branchpoints have non-blocking out-edge |
1910 | 3. all internal edges are non-relevant |
1911 | subgraphs like this need NOT contribute control-dependencies |
1912 | #endif |
1913 | |
1914 | if (!f->seen |
1915 | || (f->scratch&4)) |
1916 | return 0; |
1917 | |
1918 | if (f->scratch&8) |
1919 | return 1; |
1920 | |
1921 | f->scratch |= 4; |
1922 | |
1923 | if (verbose&32) printf("X[%d:%d:%d] ", f->from, upto, f->scratch); |
1924 | |
1925 | if (f->scratch&1) |
1926 | { if (verbose&32) |
1927 | printf("\tbad scratch: %d\n", f->from); |
1928 | bad: f->scratch &= ~4; |
1929 | /* f->scratch |= 8; wrong */ |
1930 | return 1; |
1931 | } |
1932 | |
1933 | if (f->from != upto) |
1934 | for (t = f->t; t; t = t->nxt) |
1935 | if (bad_scratch(fsm_tbl[t->to], upto)) |
1936 | goto bad; |
1937 | |
1938 | return 0; |
1939 | } |
1940 | |
1941 | static void |
1942 | mark_subgraph(FSM_state *f, int upto) |
1943 | { FSM_trans *t; |
1944 | |
1945 | if (f->from == upto |
1946 | || !f->seen |
1947 | || (f->scratch&2)) |
1948 | return; |
1949 | |
1950 | f->scratch |= 2; |
1951 | |
1952 | for (t = f->t; t; t = t->nxt) |
1953 | mark_subgraph(fsm_tbl[t->to], upto); |
1954 | } |
1955 | |
1956 | static void |
1957 | AST_pair(AST *a, FSM_state *h, int y) |
1958 | { Pair *p; |
1959 | |
1960 | for (p = a->pairs; p; p = p->nxt) |
1961 | if (p->h == h |
1962 | && p->b == y) |
1963 | return; |
1964 | |
1965 | p = (Pair *) emalloc(sizeof(Pair)); |
1966 | p->h = h; |
1967 | p->b = y; |
1968 | p->nxt = a->pairs; |
1969 | a->pairs = p; |
1970 | } |
1971 | |
1972 | static void |
1973 | AST_checkpairs(AST *a) |
1974 | { Pair *p; |
1975 | |
1976 | for (p = a->pairs; p; p = p->nxt) |
1977 | { if (verbose&32) |
1978 | printf(" inspect pair %d %d\n", p->b, p->h->from); |
1979 | if (!bad_scratch(p->h, p->b)) /* subgraph is clean */ |
1980 | { if (verbose&32) |
1981 | printf("subgraph: %d .. %d\n", p->b, p->h->from); |
1982 | mark_subgraph(p->h, p->b); |
1983 | } |
1984 | } |
1985 | } |
1986 | |
1987 | static void |
1988 | subgraph(AST *a, FSM_state *f, int out) |
1989 | { FSM_state *h; |
1990 | int i, j; |
1991 | ulong *g; |
1992 | #if 0 |
1993 | reverse dominance suggests that this is a possible |
1994 | entry and exit node for a proper subgraph |
1995 | #endif |
1996 | h = fsm_tbl[out]; |
1997 | |
1998 | i = f->from / BPW; |
1999 | j = f->from % BPW; |
2000 | g = h->mod; |
2001 | |
2002 | if (verbose&32) |
2003 | printf("possible pair %d %d -- %d\n", |
2004 | f->from, h->from, (g[i]&(1<<j))?1:0); |
2005 | |
2006 | if (g[i]&(1<<j)) /* also a forward dominance pair */ |
2007 | AST_pair(a, h, f->from); /* record this pair */ |
2008 | } |
2009 | |
2010 | static void |
2011 | act_dom(AST *a) |
2012 | { FSM_state *f; |
2013 | FSM_trans *t; |
2014 | int i, j, cnt; |
2015 | |
2016 | for (f = a->fsm; f; f = f->nxt) |
2017 | { if (!f->seen) continue; |
2018 | #if 0 |
2019 | f->from is the exit-node of a proper subgraph, with |
2020 | the dominator its entry-node, if: |
2021 | a. this node has more than 1 reachable predecessor |
2022 | b. the dominator has more than 1 reachable successor |
2023 | (need reachability - in case of reverse dominance) |
2024 | d. the dominator is reachable, and not equal to this node |
2025 | #endif |
2026 | for (t = f->p, i = 0; t; t = t->nxt) |
2027 | i += fsm_tbl[t->to]->seen; |
2028 | if (i <= 1) continue; /* a. */ |
2029 | |
2030 | for (cnt = 1; cnt < a->nstates; cnt++) /* 0 is endstate */ |
2031 | { if (cnt == f->from |
2032 | || !fsm_tbl[cnt]->seen) |
2033 | continue; /* c. */ |
2034 | |
2035 | i = cnt / BPW; |
2036 | j = cnt % BPW; |
2037 | if (!(f->dom[i]&(1<<j))) |
2038 | continue; |
2039 | |
2040 | for (t = fsm_tbl[cnt]->t, i = 0; t; t = t->nxt) |
2041 | i += fsm_tbl[t->to]->seen; |
2042 | if (i <= 1) |
2043 | continue; /* b. */ |
2044 | |
2045 | if (f->mod) /* final check in 2nd phase */ |
2046 | subgraph(a, f, cnt); /* possible entry-exit pair */ |
2047 | } |
2048 | } |
2049 | } |
2050 | |
2051 | static void |
2052 | reachability(AST *a) |
2053 | { FSM_state *f; |
2054 | |
2055 | for (f = a->fsm; f; f = f->nxt) |
2056 | f->seen = 0; /* clear */ |
2057 | AST_dfs(a, a->i_st, 0); /* mark 'seen' */ |
2058 | } |
2059 | |
2060 | static int |
2061 | see_else(FSM_state *f) |
2062 | { FSM_trans *t; |
2063 | |
2064 | for (t = f->t; t; t = t->nxt) |
2065 | { if (t->step |
2066 | && t->step->n) |
2067 | switch (t->step->n->ntyp) { |
2068 | case ELSE: |
2069 | return 1; |
2070 | case IF: |
2071 | case DO: |
2072 | case ATOMIC: |
2073 | case NON_ATOMIC: |
2074 | case D_STEP: |
2075 | if (see_else(fsm_tbl[t->to])) |
2076 | return 1; |
2077 | default: |
2078 | break; |
2079 | } |
2080 | } |
2081 | return 0; |
2082 | } |
2083 | |
2084 | static int |
2085 | is_guard(FSM_state *f) |
2086 | { FSM_state *g; |
2087 | FSM_trans *t; |
2088 | |
2089 | for (t = f->p; t; t = t->nxt) |
2090 | { g = fsm_tbl[t->to]; |
2091 | if (!g->seen) |
2092 | continue; |
2093 | |
2094 | if (t->step |
2095 | && t->step->n) |
2096 | switch(t->step->n->ntyp) { |
2097 | case IF: |
2098 | case DO: |
2099 | return 1; |
2100 | case ATOMIC: |
2101 | case NON_ATOMIC: |
2102 | case D_STEP: |
2103 | if (is_guard(g)) |
2104 | return 1; |
2105 | default: |
2106 | break; |
2107 | } |
2108 | } |
2109 | return 0; |
2110 | } |
2111 | |
2112 | static void |
2113 | curtail(AST *a) |
2114 | { FSM_state *f, *g; |
2115 | FSM_trans *t; |
2116 | int i, haselse, isrel, blocking; |
2117 | #if 0 |
2118 | mark nodes that do not satisfy these requirements: |
2119 | 1. all internal branch-points have else-s |
2120 | 2. all non-branchpoints have non-blocking out-edge |
2121 | 3. all internal edges are non-data-relevant |
2122 | #endif |
2123 | if (verbose&32) |
2124 | printf("Curtail %s:\n", a->p->n->name); |
2125 | |
2126 | for (f = a->fsm; f; f = f->nxt) |
2127 | { if (!f->seen |
2128 | || (f->scratch&(1|2))) |
2129 | continue; |
2130 | |
2131 | isrel = haselse = i = blocking = 0; |
2132 | |
2133 | for (t = f->t; t; t = t->nxt) |
2134 | { g = fsm_tbl[t->to]; |
2135 | |
2136 | isrel |= (t->relevant&1); /* data relevant */ |
2137 | i += g->seen; |
2138 | |
2139 | if (t->step |
2140 | && t->step->n) |
2141 | { switch (t->step->n->ntyp) { |
2142 | case IF: |
2143 | case DO: |
2144 | haselse |= see_else(g); |
2145 | break; |
2146 | case 'c': |
2147 | case 's': |
2148 | case 'r': |
2149 | blocking = 1; |
2150 | break; |
2151 | } } } |
2152 | #if 0 |
2153 | if (verbose&32) |
2154 | printf("prescratch %d -- %d %d %d %d -- %d\n", |
2155 | f->from, i, isrel, blocking, haselse, is_guard(f)); |
2156 | #endif |
2157 | if (isrel /* 3. */ |
2158 | || (i == 1 && blocking) /* 2. */ |
2159 | || (i > 1 && !haselse)) /* 1. */ |
2160 | { if (!is_guard(f)) |
2161 | { f->scratch |= 1; |
2162 | if (verbose&32) |
2163 | printf("scratch %d -- %d %d %d %d\n", |
2164 | f->from, i, isrel, blocking, haselse); |
2165 | } |
2166 | } |
2167 | } |
2168 | } |
2169 | |
2170 | static void |
2171 | init_dom(AST *a) |
2172 | { FSM_state *f; |
2173 | int i, j, cnt; |
2174 | #if 0 |
2175 | (1) D(s0) = {s0} |
2176 | (2) for s in S - {s0} do D(s) = S |
2177 | #endif |
2178 | |
2179 | for (f = a->fsm; f; f = f->nxt) |
2180 | { if (!f->seen) continue; |
2181 | |
2182 | f->dom = (ulong *) |
2183 | emalloc(a->nwords * sizeof(ulong)); |
2184 | |
2185 | if (f->from == a->i_st) |
2186 | { i = a->i_st / BPW; |
2187 | j = a->i_st % BPW; |
2188 | f->dom[i] = (1<<j); /* (1) */ |
2189 | } else /* (2) */ |
2190 | { for (i = 0; i < a->nwords; i++) |
2191 | f->dom[i] = (ulong) ~0; /* all 1's */ |
2192 | |
2193 | if (a->nstates % BPW) |
2194 | for (i = (a->nstates % BPW); i < (int) BPW; i++) |
2195 | f->dom[a->nwords-1] &= ~(1<<i); /* clear tail */ |
2196 | |
2197 | for (cnt = 0; cnt < a->nstates; cnt++) |
2198 | if (!fsm_tbl[cnt]->seen) |
2199 | { i = cnt / BPW; |
2200 | j = cnt % BPW; |
2201 | f->dom[i] &= ~(1<<j); |
2202 | } } } |
2203 | } |
2204 | |
2205 | static int |
2206 | dom_perculate(AST *a, FSM_state *f) |
2207 | { static ulong *ndom = (ulong *) 0; |
2208 | static int on = 0; |
2209 | int i, j, cnt = 0; |
2210 | FSM_state *g; |
2211 | FSM_trans *t; |
2212 | |
2213 | if (on < a->nwords) |
2214 | { on = a->nwords; |
2215 | ndom = (ulong *) |
2216 | emalloc(on * sizeof(ulong)); |
2217 | } |
2218 | |
2219 | for (i = 0; i < a->nwords; i++) |
2220 | ndom[i] = (ulong) ~0; |
2221 | |
2222 | for (t = f->p; t; t = t->nxt) /* all reachable predecessors */ |
2223 | { g = fsm_tbl[t->to]; |
2224 | if (g->seen) |
2225 | for (i = 0; i < a->nwords; i++) |
2226 | ndom[i] &= g->dom[i]; /* (5b) */ |
2227 | } |
2228 | |
2229 | i = f->from / BPW; |
2230 | j = f->from % BPW; |
2231 | ndom[i] |= (1<<j); /* (5a) */ |
2232 | |
2233 | for (i = 0; i < a->nwords; i++) |
2234 | if (f->dom[i] != ndom[i]) |
2235 | { cnt++; |
2236 | f->dom[i] = ndom[i]; |
2237 | } |
2238 | |
2239 | return cnt; |
2240 | } |
2241 | |
2242 | static void |
2243 | dom_forward(AST *a) |
2244 | { FSM_state *f; |
2245 | int cnt; |
2246 | |
2247 | init_dom(a); /* (1,2) */ |
2248 | do { |
2249 | cnt = 0; |
2250 | for (f = a->fsm; f; f = f->nxt) |
2251 | { if (f->seen |
2252 | && f->from != a->i_st) /* (4) */ |
2253 | cnt += dom_perculate(a, f); /* (5) */ |
2254 | } |
2255 | } while (cnt); /* (3) */ |
2256 | dom_perculate(a, fsm_tbl[a->i_st]); |
2257 | } |
2258 | |
2259 | static void |
2260 | AST_dominant(void) |
2261 | { FSM_state *f; |
2262 | FSM_trans *t; |
2263 | AST *a; |
2264 | int oi; |
2265 | static FSM_state no_state; |
2266 | #if 0 |
2267 | find dominators |
2268 | Aho, Sethi, & Ullman, Compilers - principles, techniques, and tools |
2269 | Addison-Wesley, 1986, p.671. |
2270 | |
2271 | (1) D(s0) = {s0} |
2272 | (2) for s in S - {s0} do D(s) = S |
2273 | |
2274 | (3) while any D(s) changes do |
2275 | (4) for s in S - {s0} do |
2276 | (5) D(s) = {s} union with intersection of all D(p) |
2277 | where p are the immediate predecessors of s |
2278 | |
2279 | the purpose is to find proper subgraphs |
2280 | (one entry node, one exit node) |
2281 | #endif |
2282 | if (AST_Round == 1) /* computed once, reused in every round */ |
2283 | for (a = ast; a; a = a->nxt) |
2284 | { a->nstates = 0; |
2285 | for (f = a->fsm; f; f = f->nxt) |
2286 | { a->nstates++; /* count */ |
2287 | fsm_tbl[f->from] = f; /* fast lookup */ |
2288 | f->scratch = 0; /* clear scratch marks */ |
2289 | } |
2290 | for (oi = 0; oi < a->nstates; oi++) |
2291 | if (!fsm_tbl[oi]) |
2292 | fsm_tbl[oi] = &no_state; |
2293 | |
2294 | a->nwords = (a->nstates + BPW - 1) / BPW; /* round up */ |
2295 | |
2296 | if (verbose&32) |
2297 | { printf("%s (%d): ", a->p->n->name, a->i_st); |
2298 | printf("states=%d (max %d), words = %d, bpw %d, overflow %d\n", |
2299 | a->nstates, o_max, a->nwords, |
2300 | (int) BPW, (int) (a->nstates % BPW)); |
2301 | } |
2302 | |
2303 | reachability(a); |
2304 | dom_forward(a); /* forward dominance relation */ |
2305 | |
2306 | curtail(a); /* mark ineligible edges */ |
2307 | for (f = a->fsm; f; f = f->nxt) |
2308 | { t = f->p; |
2309 | f->p = f->t; |
2310 | f->t = t; /* invert edges */ |
2311 | |
2312 | f->mod = f->dom; |
2313 | f->dom = (ulong *) 0; |
2314 | } |
2315 | oi = a->i_st; |
2316 | if (fsm_tbl[0]->seen) /* end-state reachable - else leave it */ |
2317 | a->i_st = 0; /* becomes initial state */ |
2318 | |
2319 | dom_forward(a); /* reverse dominance -- don't redo reachability! */ |
2320 | act_dom(a); /* mark proper subgraphs, if any */ |
2321 | AST_checkpairs(a); /* selectively place 2 scratch-marks */ |
2322 | |
2323 | for (f = a->fsm; f; f = f->nxt) |
2324 | { t = f->p; |
2325 | f->p = f->t; |
2326 | f->t = t; /* restore */ |
2327 | } |
2328 | a->i_st = oi; /* restore */ |
2329 | } else |
2330 | for (a = ast; a; a = a->nxt) |
2331 | { for (f = a->fsm; f; f = f->nxt) |
2332 | { fsm_tbl[f->from] = f; |
2333 | f->scratch &= 1; /* preserve 1-marks */ |
2334 | } |
2335 | for (oi = 0; oi < a->nstates; oi++) |
2336 | if (!fsm_tbl[oi]) |
2337 | fsm_tbl[oi] = &no_state; |
2338 | |
2339 | curtail(a); /* mark ineligible edges */ |
2340 | |
2341 | for (f = a->fsm; f; f = f->nxt) |
2342 | { t = f->p; |
2343 | f->p = f->t; |
2344 | f->t = t; /* invert edges */ |
2345 | } |
2346 | |
2347 | AST_checkpairs(a); /* recompute 2-marks */ |
2348 | |
2349 | for (f = a->fsm; f; f = f->nxt) |
2350 | { t = f->p; |
2351 | f->p = f->t; |
2352 | f->t = t; /* restore */ |
2353 | } } |
2354 | } |