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1 | /* | |
2 | ** Splint - annotation-assisted static program checker | |
3 | ** Copyright (C) 1994-2003 University of Virginia, | |
4 | ** Massachusetts Institute of Technology | |
5 | ** | |
6 | ** This program is free software; you can redistribute it and/or modify it | |
7 | ** under the terms of the GNU General Public License as published by the | |
8 | ** Free Software Foundation; either version 2 of the License, or (at your | |
9 | ** option) any later version. | |
10 | ** | |
11 | ** This program is distributed in the hope that it will be useful, but | |
12 | ** WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | ** General Public License for more details. | |
15 | ** | |
16 | ** The GNU General Public License is available from http://www.gnu.org/ or | |
17 | ** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
18 | ** MA 02111-1307, USA. | |
19 | ** | |
20 | ** For information on splint: info@splint.org | |
21 | ** To report a bug: splint-bug@splint.org | |
22 | ** For more information: http://www.splint.org | |
23 | */ | |
24 | ||
25 | /* | |
26 | * | |
27 | ** constraintResolve.c | |
28 | */ | |
29 | ||
30 | /* #define DEBUGPRINT 1 */ | |
31 | ||
32 | # include <ctype.h> /* for isdigit */ | |
33 | # include "splintMacros.nf" | |
34 | # include "basic.h" | |
35 | # include "cgrammar.h" | |
36 | # include "cgrammar_tokens.h" | |
37 | ||
38 | # include "exprChecks.h" | |
39 | # include "exprNodeSList.h" | |
40 | ||
41 | /*@access constraint, exprNode @*/ /*!!! NO! Don't do this so recklessly - design your code more carefully so you don't need to! */ | |
42 | ||
43 | static constraint inequalitySubstitute (/*@returned@*/ constraint p_c, constraintList p_p); | |
44 | static bool rangeCheck (arithType p_ar1, /*@observer@*/ constraintExpr p_expr1, arithType p_ar2, /*@observer@*/ constraintExpr p_expr2); | |
45 | ||
46 | static constraint inequalitySubstituteUnsound (/*@returned@*/ constraint p_c, constraintList p_p); | |
47 | static constraint inequalitySubstituteStrong (/*@returned@*/ constraint p_c, constraintList p_p); | |
48 | ||
49 | static constraint constraint_searchandreplace (/*@returned@*/ constraint p_c, constraintExpr p_old, constraintExpr p_newExpr); | |
50 | ||
51 | static constraint constraint_addOr (/*@returned@*/ constraint p_orig, /*@observer@*/ constraint p_orConstr); | |
52 | ||
53 | static bool resolveOr (/*@temp@*/constraint p_c, /*@observer@*/ /*@temp@*/ constraintList p_list); | |
54 | ||
55 | static /*@only@*/ constraintList reflectChangesEnsuresFree1 (/*@only@*/ constraintList p_pre2, constraintList p_post1); | |
56 | ||
57 | ||
58 | /*@only@*/ constraintList constraintList_mergeEnsuresFreeFirst (constraintList list1, constraintList list2) | |
59 | { | |
60 | constraintList ret; | |
61 | ||
62 | ret = constraintList_mergeEnsures (list1, list2); | |
63 | ||
64 | constraintList_free(list1); | |
65 | return ret; | |
66 | } | |
67 | ||
68 | /*@only@*/ constraintList constraintList_mergeEnsures (constraintList list1, constraintList list2) | |
69 | { | |
70 | constraintList ret; | |
71 | constraintList temp; | |
72 | ||
73 | llassert(constraintList_isDefined(list1) ); | |
74 | llassert(constraintList_isDefined(list2) ); | |
75 | ||
76 | DPRINTF(( message ("constraintList_mergeEnsures: list1 %s list2 %s", | |
77 | constraintList_print(list1), constraintList_print(list2) | |
78 | ))); | |
79 | ||
80 | ret = constraintList_fixConflicts (list1, list2); | |
81 | ret = reflectChangesEnsuresFree1 (ret, list2); | |
82 | temp = constraintList_subsumeEnsures (ret, list2); | |
83 | constraintList_free(ret); | |
84 | ret = temp; | |
85 | ||
86 | temp = constraintList_subsumeEnsures (list2, ret); | |
87 | ||
88 | temp = constraintList_addList (temp, ret); | |
89 | constraintList_free(ret); | |
90 | ||
91 | DPRINTF(( message ("constraintList_mergeEnsures: returning %s ", | |
92 | constraintList_print(temp) ) | |
93 | )); | |
94 | ||
95 | ||
96 | return temp; | |
97 | } | |
98 | ||
99 | ||
100 | /*@only@*/ constraintList constraintList_mergeRequiresFreeFirst (/*@only@*/ constraintList list1, constraintList list2) | |
101 | { | |
102 | constraintList ret; | |
103 | ||
104 | ret = constraintList_mergeRequires(list1, list2); | |
105 | ||
106 | constraintList_free(list1); | |
107 | ||
108 | return ret; | |
109 | } | |
110 | ||
111 | /*@only@*/ constraintList constraintList_mergeRequires (constraintList list1, constraintList list2) | |
112 | { | |
113 | constraintList ret; | |
114 | constraintList temp; | |
115 | ||
116 | DPRINTF((message ("constraintList_mergeRequires: merging %s and %s ", constraintList_print (list1), constraintList_print(list2) ) ) ); | |
117 | ||
118 | if (context_getFlag (FLG_REDUNDANTCONSTRAINTS) ) | |
119 | { | |
120 | ret = constraintList_copy(list1); | |
121 | ret = constraintList_addList(ret, list2); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | /* get constraints in list1 not satified by list2 */ | |
126 | temp = constraintList_reflectChanges(list1, list2); | |
127 | DPRINTF((message ("constraintList_mergeRequires: temp = %s", constraintList_print(temp) ) ) ); | |
128 | ||
129 | /*get constraints in list2 not satified by temp*/ | |
130 | ret = constraintList_reflectChanges(list2, temp); | |
131 | ||
132 | DPRINTF((message ("constraintList_mergeRequires: ret = %s", constraintList_print(ret) ) ) ); | |
133 | ||
134 | ret = constraintList_addListFree (ret, temp); | |
135 | ||
136 | DPRINTF((message ("constraintList_mergeRequires: returning %s", constraintList_print(ret) ) ) ); | |
137 | ||
138 | return ret; | |
139 | } | |
140 | ||
141 | /* old name mergeResolve renamed for czech naming convention */ | |
142 | void exprNode_mergeResolve (exprNode parent, exprNode child1, exprNode child2) | |
143 | { | |
144 | constraintList temp, temp2; | |
145 | ||
146 | DPRINTF((message ("magically merging constraint into parent:%s for", exprNode_unparse (parent) )) ); | |
147 | ||
148 | DPRINTF((message (" children: %s and %s", exprNode_unparse (child1), exprNode_unparse(child2) ) ) ); | |
149 | ||
150 | ||
151 | if (exprNode_isUndefined(parent) ) | |
152 | { | |
153 | llassert (exprNode_isDefined(parent) ); | |
154 | return; | |
155 | } | |
156 | ||
157 | ||
158 | if (exprNode_isError (child1) || exprNode_isError(child2) ) | |
159 | { | |
160 | if (exprNode_isError (child1) && !exprNode_isError(child2) ) | |
161 | { | |
162 | constraintList_free(parent->requiresConstraints); | |
163 | ||
164 | parent->requiresConstraints = constraintList_copy (child2->requiresConstraints); | |
165 | constraintList_free(parent->ensuresConstraints); | |
166 | ||
167 | parent->ensuresConstraints = constraintList_copy (child2->ensuresConstraints); | |
168 | DPRINTF((message ("Copied child constraints: pre: %s and post: %s", | |
169 | constraintList_print( child2->requiresConstraints), | |
170 | constraintList_print (child2->ensuresConstraints) | |
171 | ) | |
172 | )); | |
173 | return; | |
174 | } | |
175 | else | |
176 | { | |
177 | llassert(exprNode_isError(child2) ); | |
178 | return; | |
179 | } | |
180 | } | |
181 | ||
182 | llassert(!exprNode_isError (child1) && ! exprNode_isError(child2) ); | |
183 | ||
184 | DPRINTF((message ("Child constraints are %s %s and %s %s", | |
185 | constraintList_print (child1->requiresConstraints), | |
186 | constraintList_print (child1->ensuresConstraints), | |
187 | constraintList_print (child2->requiresConstraints), | |
188 | constraintList_print (child2->ensuresConstraints) | |
189 | ) ) ); | |
190 | ||
191 | ||
192 | constraintList_free(parent->requiresConstraints); | |
193 | ||
194 | parent->requiresConstraints = constraintList_copy (child1->requiresConstraints); | |
195 | ||
196 | if ( context_getFlag (FLG_ORCONSTRAINT) ) | |
197 | temp = constraintList_reflectChangesOr (child2->requiresConstraints, child1->ensuresConstraints); | |
198 | else | |
199 | temp = constraintList_reflectChanges(child2->requiresConstraints, child1->ensuresConstraints); | |
200 | ||
201 | temp2 = constraintList_mergeRequires (parent->requiresConstraints, temp); | |
202 | constraintList_free(parent->requiresConstraints); | |
203 | constraintList_free(temp); | |
204 | ||
205 | parent->requiresConstraints = temp2; | |
206 | ||
207 | DPRINTF((message ("Parent requires constraints are %s ", | |
208 | constraintList_print (parent->requiresConstraints) | |
209 | ) ) ); | |
210 | ||
211 | constraintList_free(parent->ensuresConstraints); | |
212 | ||
213 | parent->ensuresConstraints = constraintList_mergeEnsures(child1->ensuresConstraints, | |
214 | child2->ensuresConstraints); | |
215 | ||
216 | ||
217 | DPRINTF((message ("Parent constraints are %s and %s ", | |
218 | constraintList_print (parent->requiresConstraints), | |
219 | constraintList_print (parent->ensuresConstraints) | |
220 | ) ) ); | |
221 | ||
222 | } | |
223 | ||
224 | /*@only@*/ constraintList constraintList_subsumeEnsures (constraintList list1, constraintList list2) | |
225 | { | |
226 | constraintList ret; | |
227 | ret = constraintList_makeNew(); | |
228 | constraintList_elements (list1, el) | |
229 | { | |
230 | ||
231 | DPRINTF ((message ("Examining %s", constraint_print (el) ) ) ); | |
232 | if (!constraintList_resolve (el, list2) ) | |
233 | { | |
234 | constraint temp; | |
235 | temp = constraint_copy(el); | |
236 | ret = constraintList_add (ret, temp); | |
237 | } | |
238 | else | |
239 | { | |
240 | DPRINTF ((message ("Subsuming %s", constraint_print (el) ) ) ); | |
241 | } | |
242 | } end_constraintList_elements; | |
243 | ||
244 | return ret; | |
245 | } | |
246 | ||
247 | ||
248 | ||
249 | /*used to be reflectChangesFreePre renamed for Czech naming conventino*/ | |
250 | /* tries to resolve constraints in list pre2 using post1 */ | |
251 | /*@only@*/ constraintList constraintList_reflectChangesFreePre (/*@only@*/ constraintList pre2, /*@observer@*/ constraintList post1) | |
252 | { | |
253 | constraintList ret; | |
254 | ||
255 | ret = constraintList_reflectChanges(pre2, post1); | |
256 | ||
257 | constraintList_free (pre2); | |
258 | ||
259 | return ret; | |
260 | } | |
261 | ||
262 | /* tries to resolve constraints in list pre2 using post1 */ | |
263 | ||
264 | static /*@only@*/ constraintList reflectChangesNoOr (/*@observer@*/ /*@temp@*/ constraintList pre2, /*@observer@*/ /*@temp@*/ constraintList post1) | |
265 | { | |
266 | ||
267 | constraintList ret; | |
268 | constraint temp; | |
269 | constraint temp2; | |
270 | ||
271 | llassert (! context_getFlag (FLG_ORCONSTRAINT) ); | |
272 | ||
273 | ret = constraintList_makeNew(); | |
274 | DPRINTF((message ("reflectChanges: lists %s and %s", constraintList_print(pre2), constraintList_print(post1) ))); | |
275 | ||
276 | constraintList_elements (pre2, el) | |
277 | { | |
278 | if (!constraintList_resolve (el, post1) ) | |
279 | { | |
280 | temp = constraint_substitute (el, post1); | |
281 | if (!constraintList_resolve (temp, post1) ) | |
282 | { | |
283 | /* try inequality substitution | |
284 | the inequality substitution may cause us to lose information | |
285 | so we don't want to store the result but we do it anyway | |
286 | */ | |
287 | temp2 = constraint_copy (temp); | |
288 | temp2 = inequalitySubstitute (temp2, post1); | |
289 | if (!constraintList_resolve (temp2, post1) ) | |
290 | { | |
291 | temp2 = inequalitySubstituteUnsound (temp2, post1); | |
292 | if (!constraintList_resolve (temp2, post1) ) | |
293 | ret = constraintList_add (ret, temp2); | |
294 | else | |
295 | constraint_free(temp2); | |
296 | } | |
297 | else | |
298 | { | |
299 | constraint_free(temp2); | |
300 | } | |
301 | } | |
302 | constraint_free(temp); | |
303 | } | |
304 | } end_constraintList_elements; | |
305 | ||
306 | DPRINTF((message ("reflectChanges: returning %s", constraintList_print(ret) ) ) ); | |
307 | return ret; | |
308 | } | |
309 | ||
310 | /* tries to resolve constraints in list pre2 using post1 */ | |
311 | /*@only@*/ constraintList constraintList_reflectChanges(/*@observer@*/ constraintList pre2, /*@observer@*/ constraintList post1) | |
312 | { | |
313 | constraintList temp; | |
314 | ||
315 | if ( context_getFlag (FLG_ORCONSTRAINT) ) | |
316 | ||
317 | temp = constraintList_reflectChangesOr (pre2, post1); | |
318 | else | |
319 | temp = reflectChangesNoOr(pre2, post1); | |
320 | ||
321 | return temp; | |
322 | } | |
323 | ||
324 | static constraint constraint_addOr (/*@returned@*/ constraint orig, /*@observer@*/ constraint orConstr) | |
325 | { | |
326 | constraint c; | |
327 | ||
328 | llassert(constraint_isDefined(orig) ); | |
329 | ||
330 | c = orig; | |
331 | ||
332 | DPRINTF((message("constraint_addor: oring %s onto %s", constraint_printOr(orConstr), constraint_printOr(orig) ) )); | |
333 | ||
334 | while (c->or != NULL) | |
335 | { | |
336 | c = c->or; | |
337 | } | |
338 | ||
339 | c->or = constraint_copy(orConstr); | |
340 | ||
341 | DPRINTF((message("constraint_addor: returning %s",constraint_printOr(orig) ) )); | |
342 | ||
343 | return orig; | |
344 | } | |
345 | ||
346 | ||
347 | static bool resolveOr ( /*@temp@*/ constraint c, /*@observer@*/ /*@temp@*/ constraintList list) | |
348 | { | |
349 | constraint temp; | |
350 | ||
351 | int numberOr; | |
352 | ||
353 | numberOr = 0; | |
354 | ||
355 | llassert(constraint_isDefined(c) ); | |
356 | ||
357 | DPRINTF(( message("resolveOr: constraint %s and list %s", constraint_printOr(c), constraintList_print(list) ) )); | |
358 | ||
359 | temp = c; | |
360 | ||
361 | do | |
362 | { | |
363 | if (constraintList_resolve (temp, list) ) | |
364 | return TRUE; | |
365 | temp = temp->or; | |
366 | numberOr++; | |
367 | llassert(numberOr <= 10); | |
368 | } | |
369 | while (constraint_isDefined(temp)); | |
370 | ||
371 | return FALSE; | |
372 | } | |
373 | ||
374 | /*This is a "helper" function for doResolveOr */ | |
375 | ||
376 | static /*@only@*/ constraint doResolve (/*@only@*/ constraint c, constraintList post1, bool * resolved) | |
377 | { | |
378 | constraint temp; | |
379 | ||
380 | llassert(constraint_isDefined (c ) ); | |
381 | ||
382 | DPRINTF((message("doResolve:: call on constraint c = : %q and constraintList %q", | |
383 | constraint_printOr(c), constraintList_print(post1) | |
384 | ) | |
385 | )); | |
386 | ||
387 | if (!resolveOr (c, post1) ) | |
388 | { | |
389 | ||
390 | temp = constraint_substitute (c, post1); | |
391 | ||
392 | DPRINTF((message("doResolve:: after substitute temp is %q", | |
393 | constraint_printOr(temp) | |
394 | ) | |
395 | )); | |
396 | ||
397 | if (!resolveOr (temp, post1) ) | |
398 | { | |
399 | /* try inequality substitution */ | |
400 | constraint temp2; | |
401 | ||
402 | /* the inequality substitution may cause us to lose information | |
403 | so we don't want to store the result but we do anyway | |
404 | */ | |
405 | temp2 = constraint_copy (c); | |
406 | temp2 = inequalitySubstitute (temp2, post1); | |
407 | ||
408 | if (!resolveOr (temp2, post1) ) | |
409 | { | |
410 | constraint temp3; | |
411 | temp3 = constraint_copy(temp2); | |
412 | ||
413 | temp3 = inequalitySubstituteStrong (temp3, post1); | |
414 | if (!resolveOr (temp3, post1) ) | |
415 | { | |
416 | temp2 = inequalitySubstituteUnsound (temp2, post1); | |
417 | if (!resolveOr (temp2, post1) ) | |
418 | { | |
419 | if (!constraint_same (temp, temp2) ) | |
420 | { | |
421 | /* drl added 8/28/2002*/ | |
422 | /*make sure that the information from | |
423 | a post condition like i = i + 1 is transfered | |
424 | */ | |
425 | constraint tempSub; | |
426 | tempSub = constraint_substitute (temp2, post1); | |
427 | ||
428 | DPRINTF(( | |
429 | message("doResolve: adding %s ", | |
430 | constraint_printOr(tempSub) | |
431 | ) | |
432 | )); | |
433 | ||
434 | DPRINTF(( | |
435 | message("doResolve: not adding %s ", | |
436 | constraint_printOr(temp2) | |
437 | ) | |
438 | )); | |
439 | ||
440 | temp = constraint_addOr (temp, tempSub); | |
441 | constraint_free(tempSub); | |
442 | ||
443 | } | |
444 | if (!constraint_same (temp, temp3) && !constraint_same (temp3, temp2) ) | |
445 | { | |
446 | /* drl added 8/28/2002*/ | |
447 | /*make sure that the information from | |
448 | a post condition like i = i + 1 is transfered | |
449 | */ | |
450 | constraint tempSub; | |
451 | ||
452 | tempSub = constraint_substitute (temp3, post1); | |
453 | ||
454 | DPRINTF(( | |
455 | message("doResolve: adding %s ", | |
456 | constraint_printOr(tempSub) | |
457 | ) | |
458 | )); | |
459 | ||
460 | ||
461 | DPRINTF(( | |
462 | message("doResolve: not adding %s ", | |
463 | constraint_printOr(temp3) | |
464 | ) | |
465 | )); | |
466 | ||
467 | temp = constraint_addOr (temp, tempSub); | |
468 | ||
469 | constraint_free(tempSub); | |
470 | } | |
471 | *resolved = FALSE; | |
472 | ||
473 | constraint_free(temp2); | |
474 | constraint_free(temp3); | |
475 | constraint_free(c); | |
476 | ||
477 | return temp; | |
478 | } | |
479 | constraint_free(temp2); | |
480 | constraint_free(temp3); | |
481 | } | |
482 | else | |
483 | { | |
484 | constraint_free(temp2); | |
485 | constraint_free(temp3); | |
486 | } | |
487 | } | |
488 | else | |
489 | { | |
490 | constraint_free(temp2); | |
491 | } | |
492 | ||
493 | } | |
494 | constraint_free(temp); | |
495 | } | |
496 | constraint_free(c); | |
497 | ||
498 | *resolved = TRUE; | |
499 | return NULL; | |
500 | } | |
501 | ||
502 | static /*@only@*/ constraint doResolveOr (/*@observer@*/ /*@temp@*/ constraint c, constraintList post1, /*@out@*/bool * resolved) | |
503 | { | |
504 | constraint ret; | |
505 | constraint next; | |
506 | constraint curr; | |
507 | ||
508 | DPRINTF(( message("doResolveOr: constraint %s and list %s", constraint_printOr(c), constraintList_print(post1) ) )); | |
509 | ||
510 | *resolved = FALSE; | |
511 | ||
512 | llassert(constraint_isDefined(c) ); | |
513 | ||
514 | ret = constraint_copy(c); | |
515 | ||
516 | llassert(constraint_isDefined(ret) ); | |
517 | ||
518 | if (constraintList_isEmpty(post1) ) | |
519 | { | |
520 | return ret; | |
521 | } | |
522 | ||
523 | next = ret->or; | |
524 | ret->or = NULL; | |
525 | ||
526 | ret = doResolve (ret, post1, resolved); | |
527 | ||
528 | if (*resolved) | |
529 | { | |
530 | if (next != NULL) | |
531 | constraint_free(next); | |
532 | ||
533 | /*we don't need to free ret when resolved is false because ret is null*/ | |
534 | llassert(ret == NULL); | |
535 | ||
536 | return NULL; | |
537 | } | |
538 | ||
539 | while (next != NULL) | |
540 | { | |
541 | curr = next; | |
542 | next = curr->or; | |
543 | curr->or = NULL; | |
544 | ||
545 | curr = doResolve (curr, post1, resolved); | |
546 | ||
547 | if (*resolved) | |
548 | { | |
549 | /* curr is null so we don't try to free it*/ | |
550 | llassert(curr == NULL); | |
551 | ||
552 | if (next != NULL) | |
553 | constraint_free(next); | |
554 | ||
555 | constraint_free(ret); | |
556 | return NULL; | |
557 | } | |
558 | ret = constraint_addOr (ret, curr); | |
559 | constraint_free(curr); | |
560 | } | |
561 | return ret; | |
562 | } | |
563 | ||
564 | /* tries to resolve constraints in list pr2 using post1 */ | |
565 | /*@only@*/ constraintList constraintList_reflectChangesOr (constraintList pre2, constraintList post1) | |
566 | { | |
567 | bool resolved; | |
568 | constraintList ret; | |
569 | constraint temp; | |
570 | ret = constraintList_makeNew(); | |
571 | DPRINTF((message ("constraintList_reflectChangesOr: lists %s and %s", constraintList_print(pre2), constraintList_print(post1) ))); | |
572 | ||
573 | constraintList_elements (pre2, el) | |
574 | { | |
575 | temp = doResolveOr (el, post1, &resolved); | |
576 | ||
577 | if (!resolved) | |
578 | { | |
579 | ret = constraintList_add(ret, temp); | |
580 | } | |
581 | else | |
582 | { | |
583 | /* we don't need to free temp when | |
584 | resolved is false because temp is null */ | |
585 | llassert(temp == NULL); | |
586 | } | |
587 | ||
588 | } end_constraintList_elements; | |
589 | ||
590 | DPRINTF((message ("constraintList_reflectChangesOr: returning %s", constraintList_print(ret) ) ) ); | |
591 | return ret; | |
592 | } | |
593 | ||
594 | static /*@only@*/ constraintList reflectChangesEnsures (/*@observer@*/ constraintList pre2, constraintList post1) | |
595 | { | |
596 | constraintList ret; | |
597 | constraint temp; | |
598 | ret = constraintList_makeNew(); | |
599 | constraintList_elements (pre2, el) | |
600 | { | |
601 | if (!constraintList_resolve (el, post1) ) | |
602 | { | |
603 | temp = constraint_substitute (el, post1); | |
604 | llassert (temp != NULL); | |
605 | ||
606 | if (!constraintList_resolve (temp, post1) ) | |
607 | ret = constraintList_add (ret, temp); | |
608 | else | |
609 | constraint_free(temp); | |
610 | } | |
611 | else | |
612 | { | |
613 | DPRINTF ((message ("Resolved away %s ", constraint_print(el) ) ) ); | |
614 | } | |
615 | } end_constraintList_elements; | |
616 | ||
617 | return ret; | |
618 | } | |
619 | ||
620 | ||
621 | static /*@only@*/ constraintList reflectChangesEnsuresFree1 (/*@only@*/ constraintList pre2, constraintList post1) | |
622 | { | |
623 | constraintList ret; | |
624 | ||
625 | ret = reflectChangesEnsures (pre2, post1); | |
626 | ||
627 | constraintList_free(pre2); | |
628 | ||
629 | return ret; | |
630 | } | |
631 | ||
632 | ||
633 | static bool constraint_conflict (constraint c1, constraint c2) | |
634 | { | |
635 | if (!constraint_isDefined(c1) || !constraint_isDefined(c2)) | |
636 | { | |
637 | return FALSE; | |
638 | } | |
639 | ||
640 | if (constraintExpr_similar (c1->lexpr, c2->lexpr)) | |
641 | { | |
642 | if (c1->ar == EQ) | |
643 | if (c1->ar == c2->ar) | |
644 | { | |
645 | DPRINTF (("%s conflicts with %s", constraint_unparse (c1), constraint_unparse (c2))); | |
646 | return TRUE; | |
647 | } | |
648 | } | |
649 | ||
650 | /* This is a slight kludge to prevent circular constraints like | |
651 | strlen(str) == maxRead(s) + strlen(str); | |
652 | */ | |
653 | ||
654 | /*this code is functional but it may be worth cleaning up at some point. */ | |
655 | ||
656 | if (c1->ar == EQ) | |
657 | if (c1->ar == c2->ar) | |
658 | { | |
659 | if (constraintExpr_search (c1->lexpr, c2->expr) ) | |
660 | if (constraintExpr_isTerm(c1->lexpr) ) | |
661 | { | |
662 | constraintTerm term; | |
663 | ||
664 | term = constraintExpr_getTerm(c1->lexpr); | |
665 | ||
666 | if (constraintTerm_isExprNode(term) ) | |
667 | { | |
668 | DPRINTF ((message ("%s conflicts with %s ", constraint_print (c1), constraint_print(c2) ) ) ); | |
669 | return TRUE; | |
670 | } | |
671 | } | |
672 | } | |
673 | ||
674 | if (constraint_tooDeep(c1) || constraint_tooDeep(c2) ) | |
675 | { | |
676 | DPRINTF ((message ("%s conflicts with %s (constraint is too deep", constraint_print (c1), constraint_print(c2) ) ) ); | |
677 | return TRUE; | |
678 | } | |
679 | ||
680 | DPRINTF ((message ("%s doesn't conflict with %s ", constraint_print (c1), constraint_print(c2) ) ) ); | |
681 | ||
682 | return FALSE; | |
683 | ||
684 | } | |
685 | ||
686 | static void constraint_fixConflict (/*@temp@*/ constraint good, /*@temp@*/ /*@observer@*/ constraint conflicting) /*@modifies good@*/ | |
687 | { | |
688 | llassert(constraint_isDefined(conflicting) ); | |
689 | ||
690 | if (conflicting->ar == EQ) | |
691 | { | |
692 | llassert (constraint_isDefined(good)); | |
693 | DPRINTF (("Replacing here!")); | |
694 | good->expr = constraintExpr_searchandreplace (good->expr, conflicting->lexpr, conflicting->expr); | |
695 | good = constraint_simplify (good); | |
696 | } | |
697 | ||
698 | ||
699 | } | |
700 | ||
701 | static bool conflict (constraint c, constraintList list) | |
702 | { | |
703 | ||
704 | constraintList_elements (list, el) | |
705 | { | |
706 | if ( constraint_conflict(el, c) ) | |
707 | { | |
708 | constraint_fixConflict (el, c); | |
709 | return TRUE; | |
710 | } | |
711 | } end_constraintList_elements; | |
712 | ||
713 | return FALSE; | |
714 | ||
715 | } | |
716 | ||
717 | /* | |
718 | check if constraint in list1 conflicts with constraints in List2. If so we | |
719 | remove form list1 and change list2. | |
720 | */ | |
721 | ||
722 | constraintList constraintList_fixConflicts (constraintList list1, constraintList list2) | |
723 | { | |
724 | constraintList ret; | |
725 | ret = constraintList_makeNew(); | |
726 | llassert(constraintList_isDefined(list1) ); | |
727 | constraintList_elements (list1, el) | |
728 | { | |
729 | if (! conflict (el, list2) ) | |
730 | { | |
731 | constraint temp; | |
732 | temp = constraint_copy(el); | |
733 | ret = constraintList_add (ret, temp); | |
734 | } | |
735 | } end_constraintList_elements; | |
736 | ||
737 | return ret; | |
738 | } | |
739 | ||
740 | /*returns true if constraint post satisfies cosntriant pre */ | |
741 | ||
742 | static bool constraintResolve_satisfies (constraint pre, constraint post) | |
743 | { | |
744 | if (!constraint_isDefined (pre)) | |
745 | { | |
746 | return TRUE; | |
747 | } | |
748 | ||
749 | if (!constraint_isDefined(post)) | |
750 | { | |
751 | return FALSE; | |
752 | } | |
753 | ||
754 | if (constraint_isAlwaysTrue (pre)) | |
755 | return TRUE; | |
756 | ||
757 | if (!constraintExpr_similar (pre->lexpr, post->lexpr) ) | |
758 | { | |
759 | return FALSE; | |
760 | } | |
761 | ||
762 | if (constraintExpr_isUndefined(post->expr)) | |
763 | { | |
764 | llassert(FALSE); | |
765 | return FALSE; | |
766 | } | |
767 | ||
768 | return rangeCheck (pre->ar, pre->expr, post->ar, post->expr); | |
769 | } | |
770 | ||
771 | ||
772 | bool constraintList_resolve (/*@temp@*/ /*@observer@*/ constraint c, | |
773 | /*@temp@*/ /*@observer@*/ constraintList p) | |
774 | { | |
775 | DPRINTF (("[resolve] Trying to resolve constraint: %s using %s", | |
776 | constraint_unparse (c), | |
777 | constraintList_unparse (p))); | |
778 | ||
779 | constraintList_elements (p, el) | |
780 | { | |
781 | if (constraintResolve_satisfies (c, el)) | |
782 | { | |
783 | DPRINTF (("constraintList_resolve: %s satifies %s", | |
784 | constraint_unparse (el), constraint_unparse (c))); | |
785 | return TRUE; | |
786 | } | |
787 | ||
788 | DPRINTF (("constraintList_resolve: %s does not satify %s\n ", | |
789 | constraint_unparse (el), constraint_unparse (c))); | |
790 | } | |
791 | end_constraintList_elements; | |
792 | ||
793 | DPRINTF (("No constraints satify: %s", constraint_unparse (c))); | |
794 | return FALSE; | |
795 | } | |
796 | ||
797 | static bool arithType_canResolve (arithType ar1, arithType ar2) | |
798 | { | |
799 | switch (ar1) | |
800 | { | |
801 | case GTE: | |
802 | case GT: | |
803 | if ((ar2 == GT) || (ar2 == GTE) || (ar2 == EQ)) | |
804 | { | |
805 | return TRUE; | |
806 | } | |
807 | break; | |
808 | ||
809 | case EQ: | |
810 | if (ar2 == EQ) | |
811 | return TRUE; | |
812 | break; | |
813 | ||
814 | case LT: | |
815 | case LTE: | |
816 | if ((ar2 == LT) || (ar2 == LTE) || (ar2 == EQ)) | |
817 | return TRUE; | |
818 | break; | |
819 | default: | |
820 | return FALSE; | |
821 | } | |
822 | return FALSE; | |
823 | } | |
824 | ||
825 | /*checks for the case expr2 == sizeof buf1 and buf1 is a fixed array*/ | |
826 | static bool sizeofBufComp(constraintExpr buf1, constraintExpr expr2) | |
827 | { | |
828 | constraintTerm ct; | |
829 | exprNode e, t; | |
830 | sRef s1, s2; | |
831 | ||
832 | llassert(constraintExpr_isDefined(buf1) && constraintExpr_isDefined(expr2) ); | |
833 | ||
834 | /*@access constraintExpr@*/ | |
835 | ||
836 | if ((expr2->kind != term) && (buf1->kind != term) ) | |
837 | return FALSE; | |
838 | ||
839 | ||
840 | ct = constraintExprData_termGetTerm(expr2->data); | |
841 | ||
842 | if (!constraintTerm_isExprNode(ct) ) | |
843 | return FALSE; | |
844 | ||
845 | e = constraintTerm_getExprNode(ct); | |
846 | ||
847 | llassert (exprNode_isDefined(e)); | |
848 | ||
849 | if (! (exprNode_isDefined(e))) | |
850 | return FALSE; | |
851 | ||
852 | if (e->kind != XPR_SIZEOF) | |
853 | return FALSE; | |
854 | ||
855 | t = exprData_getSingle (e->edata); | |
856 | s1 = exprNode_getSref (t); | |
857 | ||
858 | s2 = constraintTerm_getsRef(constraintExprData_termGetTerm(buf1->data) ); | |
859 | ||
860 | /*drl this may be the wronge thing to test for but this | |
861 | seems to work correctly*/ | |
862 | if (sRef_similarRelaxed(s1, s2) || sRef_sameName (s1, s2) ) | |
863 | { | |
864 | /* origly checked that ctype_isFixedArray(sRef_getType(s2)) but | |
865 | removed that test */ | |
866 | return TRUE; | |
867 | } | |
868 | return FALSE; | |
869 | } | |
870 | ||
871 | /* look for the special case of | |
872 | maxSet(buf) >= sizeof(buf) - 1 | |
873 | */ | |
874 | ||
875 | /*drl eventually it would be good to check that | |
876 | buf is of type char.*/ | |
877 | ||
878 | static bool sizeOfMaxSet( /*@observer@*/ /*@temp@*/ constraint c) | |
879 | { | |
880 | constraintExpr l, r, buf1, buf2, con; | |
881 | ||
882 | DPRINTF(( message("sizeOfMaxSet: checking %s ", constraint_print(c) ) | |
883 | )); | |
884 | ||
885 | llassert (constraint_isDefined(c) ); | |
886 | ||
887 | l = c->lexpr; | |
888 | r = c->expr; | |
889 | ||
890 | if (!((c->ar == EQ) || (c->ar == GTE) || (c->ar == LTE) ) ) | |
891 | return FALSE; | |
892 | ||
893 | llassert (constraintExpr_isDefined(l) ); | |
894 | llassert (constraintExpr_isDefined(r) ); | |
895 | ||
896 | /*check if the constraintExpr is MaxSet(buf) */ | |
897 | if (l->kind == unaryExpr) | |
898 | { | |
899 | if (constraintExprData_unaryExprGetOp(l->data) == MAXSET) | |
900 | { | |
901 | buf1 = constraintExprData_unaryExprGetExpr(l->data); | |
902 | } | |
903 | else | |
904 | return FALSE; | |
905 | } | |
906 | else | |
907 | return FALSE; | |
908 | ||
909 | ||
910 | if (r->kind != binaryexpr) | |
911 | return FALSE; | |
912 | ||
913 | buf2 = constraintExprData_binaryExprGetExpr1(r->data); | |
914 | con = constraintExprData_binaryExprGetExpr2(r->data); | |
915 | ||
916 | if (constraintExprData_binaryExprGetOp(r->data) == BINARYOP_MINUS) | |
917 | { | |
918 | if (constraintExpr_canGetValue(con) ) | |
919 | { | |
920 | long i; | |
921 | ||
922 | i = constraintExpr_getValue(con); | |
923 | if (i != 1) | |
924 | { | |
925 | return FALSE; | |
926 | } | |
927 | } | |
928 | else | |
929 | return FALSE; | |
930 | } | |
931 | ||
932 | if (constraintExprData_binaryExprGetOp(r->data) == BINARYOP_PLUS) | |
933 | { | |
934 | if (constraintExpr_canGetValue(con) ) | |
935 | { | |
936 | long i; | |
937 | ||
938 | i = constraintExpr_getValue(con); | |
939 | if (i != -1) | |
940 | { | |
941 | return FALSE; | |
942 | } | |
943 | } | |
944 | else | |
945 | return FALSE; | |
946 | } | |
947 | ||
948 | if (sizeofBufComp(buf1, buf2)) | |
949 | { | |
950 | return TRUE; | |
951 | } | |
952 | else | |
953 | { | |
954 | return FALSE; | |
955 | } | |
956 | } | |
957 | /*@noaccess constraintExpr@*/ | |
958 | ||
959 | /* We look for constraint which are tautologies */ | |
960 | ||
961 | bool constraint_isAlwaysTrue (/*@observer@*/ /*@temp@*/ constraint c) | |
962 | { | |
963 | constraintExpr l, r; | |
964 | bool rHasConstant; | |
965 | int rConstant; | |
966 | ||
967 | ||
968 | llassert (constraint_isDefined(c) ); | |
969 | ||
970 | l = c->lexpr; | |
971 | r = c->expr; | |
972 | ||
973 | DPRINTF(( message("constraint_IsAlwaysTrue:examining %s", constraint_print(c) ) )); | |
974 | ||
975 | if (sizeOfMaxSet(c) ) | |
976 | return TRUE; | |
977 | ||
978 | if (constraintExpr_canGetValue(l) && constraintExpr_canGetValue(r) ) | |
979 | { | |
980 | int cmp; | |
981 | cmp = constraintExpr_compare (l, r); | |
982 | switch (c->ar) | |
983 | { | |
984 | case EQ: | |
985 | return (cmp == 0); | |
986 | case GT: | |
987 | return (cmp > 0); | |
988 | case GTE: | |
989 | return (cmp >= 0); | |
990 | case LTE: | |
991 | return (cmp <= 0); | |
992 | case LT: | |
993 | return (cmp < 0); | |
994 | ||
995 | default: | |
996 | BADEXIT; | |
997 | /*@notreached@*/ | |
998 | break; | |
999 | } | |
1000 | } | |
1001 | ||
1002 | if (constraintExpr_similar (l,r)) | |
1003 | { | |
1004 | switch (c->ar) | |
1005 | { | |
1006 | case EQ: | |
1007 | case GTE: | |
1008 | case LTE: | |
1009 | return TRUE; | |
1010 | ||
1011 | case GT: | |
1012 | case LT: | |
1013 | break; | |
1014 | default: | |
1015 | BADEXIT; | |
1016 | /*@notreached@*/ | |
1017 | break; | |
1018 | } | |
1019 | } | |
1020 | ||
1021 | l = constraintExpr_copy (c->lexpr); | |
1022 | r = constraintExpr_copy (c->expr); | |
1023 | ||
1024 | r = constraintExpr_propagateConstants (r, &rHasConstant, &rConstant); | |
1025 | ||
1026 | if (constraintExpr_similar (l,r) && (rHasConstant ) ) | |
1027 | { | |
1028 | DPRINTF(( message("constraint_IsAlwaysTrue: after removing constants %s and %s are similar", constraintExpr_unparse(l), constraintExpr_unparse(r) ) )); | |
1029 | DPRINTF(( message("constraint_IsAlwaysTrue: rconstant is %d", rConstant ) )); | |
1030 | ||
1031 | constraintExpr_free(l); | |
1032 | constraintExpr_free(r); | |
1033 | ||
1034 | switch (c->ar) | |
1035 | { | |
1036 | case EQ: | |
1037 | return (rConstant == 0); | |
1038 | case LT: | |
1039 | return (rConstant > 0); | |
1040 | case LTE: | |
1041 | return (rConstant >= 0); | |
1042 | case GTE: | |
1043 | return (rConstant <= 0); | |
1044 | case GT: | |
1045 | return (rConstant < 0); | |
1046 | ||
1047 | default: | |
1048 | BADEXIT; | |
1049 | /*@notreached@*/ | |
1050 | break; | |
1051 | } | |
1052 | } | |
1053 | else | |
1054 | { | |
1055 | constraintExpr_free(l); | |
1056 | constraintExpr_free(r); | |
1057 | DPRINTF(( message("Constraint %s is not always true", constraint_print(c) ) )); | |
1058 | return FALSE; | |
1059 | } | |
1060 | ||
1061 | BADEXIT; | |
1062 | } | |
1063 | ||
1064 | static bool rangeCheck (arithType ar1, /*@observer@*/ constraintExpr expr1, arithType ar2, /*@observer@*/ constraintExpr expr2) | |
1065 | ||
1066 | { | |
1067 | DPRINTF (("Doing range check %s and %s", | |
1068 | constraintExpr_unparse (expr1), constraintExpr_unparse (expr2))); | |
1069 | ||
1070 | if (!arithType_canResolve (ar1, ar2)) | |
1071 | return FALSE; | |
1072 | ||
1073 | switch (ar1) | |
1074 | { | |
1075 | case GTE: | |
1076 | if (constraintExpr_similar (expr1, expr2) ) | |
1077 | return TRUE; | |
1078 | /*@fallthrough@*/ | |
1079 | case GT: | |
1080 | if (! (constraintExpr_canGetValue (expr1) && | |
1081 | constraintExpr_canGetValue (expr2) ) ) | |
1082 | { | |
1083 | constraintExpr e1, e2; | |
1084 | bool p1, p2; | |
1085 | int const1, const2; | |
1086 | ||
1087 | e1 = constraintExpr_copy(expr1); | |
1088 | e2 = constraintExpr_copy(expr2); | |
1089 | ||
1090 | e1 = constraintExpr_propagateConstants (e1, &p1, &const1); | |
1091 | e2 = constraintExpr_propagateConstants (e2, &p2, &const2); | |
1092 | ||
1093 | if (p1 || p2) | |
1094 | { | |
1095 | if (!p1) | |
1096 | const1 = 0; | |
1097 | ||
1098 | if (!p2) | |
1099 | const2 = 0; | |
1100 | ||
1101 | if (const1 <= const2) | |
1102 | if (constraintExpr_similar (e1, e2) ) | |
1103 | { | |
1104 | constraintExpr_free(e1); | |
1105 | constraintExpr_free(e2); | |
1106 | return TRUE; | |
1107 | } | |
1108 | } | |
1109 | DPRINTF(("Can't Get value")); | |
1110 | ||
1111 | constraintExpr_free(e1); | |
1112 | constraintExpr_free(e2); | |
1113 | return FALSE; | |
1114 | } | |
1115 | ||
1116 | if (constraintExpr_compare (expr2, expr1) >= 0) | |
1117 | return TRUE; | |
1118 | ||
1119 | return FALSE; | |
1120 | case EQ: | |
1121 | if (constraintExpr_similar (expr1, expr2) ) | |
1122 | return TRUE; | |
1123 | ||
1124 | return FALSE; | |
1125 | case LTE: | |
1126 | if (constraintExpr_similar (expr1, expr2) ) | |
1127 | return TRUE; | |
1128 | /*@fallthrough@*/ | |
1129 | case LT: | |
1130 | if (! (constraintExpr_canGetValue (expr1) && | |
1131 | constraintExpr_canGetValue (expr2) ) ) | |
1132 | { | |
1133 | constraintExpr e1, e2; | |
1134 | bool p1, p2; | |
1135 | int const1, const2; | |
1136 | ||
1137 | e1 = constraintExpr_copy(expr1); | |
1138 | e2 = constraintExpr_copy(expr2); | |
1139 | ||
1140 | e1 = constraintExpr_propagateConstants (e1, &p1, &const1); | |
1141 | ||
1142 | e2 = constraintExpr_propagateConstants (e2, &p2, &const2); | |
1143 | ||
1144 | if (p1 || p2) | |
1145 | { | |
1146 | if (!p1) | |
1147 | const1 = 0; | |
1148 | ||
1149 | if (!p2) | |
1150 | const2 = 0; | |
1151 | ||
1152 | if (const1 >= const2) | |
1153 | if (constraintExpr_similar (e1, e2) ) | |
1154 | { | |
1155 | constraintExpr_free(e1); | |
1156 | constraintExpr_free(e2); | |
1157 | return TRUE; | |
1158 | } | |
1159 | } | |
1160 | constraintExpr_free(e1); | |
1161 | constraintExpr_free(e2); | |
1162 | ||
1163 | DPRINTF(("Can't Get value")); | |
1164 | return FALSE; | |
1165 | } | |
1166 | ||
1167 | if (constraintExpr_compare (expr2, expr1) <= 0) | |
1168 | return TRUE; | |
1169 | ||
1170 | return FALSE; | |
1171 | ||
1172 | default: | |
1173 | llcontbug((message("Unhandled case in switch: %q", arithType_print(ar1) ) ) ); | |
1174 | } | |
1175 | BADEXIT; | |
1176 | } | |
1177 | ||
1178 | static constraint constraint_searchandreplace (/*@returned@*/ constraint c, constraintExpr old, constraintExpr newExpr) | |
1179 | { | |
1180 | llassert (constraint_isDefined(c)); | |
1181 | ||
1182 | DPRINTF (("Starting replace lexpr [%p]: %s < %s ==> %s > in %s", c, | |
1183 | constraintExpr_unparse (c->lexpr), | |
1184 | constraintExpr_unparse (old), constraintExpr_unparse (newExpr), | |
1185 | constraint_unparse (c))); | |
1186 | c->lexpr = constraintExpr_searchandreplace (c->lexpr, old, newExpr); | |
1187 | DPRINTF (("Finished replace lexpr [%p]: %s", c, constraintExpr_unparse (c->lexpr))); | |
1188 | c->expr = constraintExpr_searchandreplace (c->expr, old, newExpr); | |
1189 | return c; | |
1190 | } | |
1191 | ||
1192 | bool constraint_search (constraint c, constraintExpr old) /*@*/ | |
1193 | { | |
1194 | bool ret; | |
1195 | ret = FALSE; | |
1196 | ||
1197 | llassert (constraint_isDefined (c)); | |
1198 | ||
1199 | ret = constraintExpr_search (c->lexpr, old); | |
1200 | ret = ret || constraintExpr_search (c->expr, old); | |
1201 | return ret; | |
1202 | } | |
1203 | ||
1204 | /* adjust file locs and stuff */ | |
1205 | static constraint constraint_adjust (/*@returned@*/ constraint substitute, /*@observer@*/ constraint old) | |
1206 | { | |
1207 | fileloc loc1, loc2, loc3; | |
1208 | ||
1209 | DPRINTF ((message("Start adjust on %s and %s", constraint_print(substitute), | |
1210 | constraint_print(old)) | |
1211 | )); | |
1212 | ||
1213 | llassert(constraint_isDefined(substitute)); | |
1214 | llassert(constraint_isDefined(old)); | |
1215 | ||
1216 | loc1 = constraint_getFileloc (old); | |
1217 | loc2 = constraintExpr_loc (substitute->lexpr); | |
1218 | loc3 = constraintExpr_loc (substitute->expr); | |
1219 | ||
1220 | /* special case of an equality that "contains itself" */ | |
1221 | if (constraintExpr_search (substitute->expr, substitute->lexpr) ) | |
1222 | if (fileloc_closer (loc1, loc3, loc2)) | |
1223 | { | |
1224 | constraintExpr temp; | |
1225 | DPRINTF ((message("Doing adjust on %s", constraint_print(substitute) ) | |
1226 | )); | |
1227 | temp = substitute->lexpr; | |
1228 | substitute->lexpr = substitute->expr; | |
1229 | substitute->expr = temp; | |
1230 | substitute = constraint_simplify(substitute); | |
1231 | } | |
1232 | ||
1233 | fileloc_free (loc1); | |
1234 | fileloc_free (loc2); | |
1235 | fileloc_free (loc3); | |
1236 | ||
1237 | return substitute; | |
1238 | ||
1239 | } | |
1240 | ||
1241 | /* If function preforms substitutes based on inequality | |
1242 | ||
1243 | It uses the rule x >= y && b < y ===> x >= b + 1 | |
1244 | ||
1245 | Warning this is sound but throws out information | |
1246 | */ | |
1247 | ||
1248 | constraint inequalitySubstitute (/*@returned@*/ constraint c, constraintList p) | |
1249 | { | |
1250 | llassert(constraint_isDefined(c) ); | |
1251 | ||
1252 | if (c->ar != GTE) | |
1253 | return c; | |
1254 | ||
1255 | constraintList_elements (p, el) | |
1256 | { | |
1257 | ||
1258 | llassert(constraint_isDefined(el) ); | |
1259 | ||
1260 | if ((el->ar == LT ) ) | |
1261 | { | |
1262 | constraintExpr temp2; | |
1263 | ||
1264 | if (constraintExpr_same (el->expr, c->expr) ) | |
1265 | { | |
1266 | DPRINTF((message ("inequalitySubstitute Replacing %q in %q with %q", | |
1267 | constraintExpr_print (c->expr), | |
1268 | constraint_print (c), | |
1269 | constraintExpr_print (el->expr) ) | |
1270 | )); | |
1271 | temp2 = constraintExpr_copy (el->lexpr); | |
1272 | constraintExpr_free(c->expr); | |
1273 | c->expr = constraintExpr_makeIncConstraintExpr (temp2); | |
1274 | ||
1275 | } | |
1276 | ||
1277 | } | |
1278 | } | |
1279 | end_constraintList_elements; | |
1280 | ||
1281 | c = constraint_simplify(c); | |
1282 | return c; | |
1283 | } | |
1284 | ||
1285 | ||
1286 | /* drl7x 7/26/001 | |
1287 | ||
1288 | THis function is like inequalitySubstitute but it adds the rule | |
1289 | added the rules x >= y && y <= b ===> x >= b | |
1290 | x >= y && y < b ===> x >= b + 1 | |
1291 | ||
1292 | This is sound but sonce it throws out additional information it should only one used | |
1293 | if we're oring constraints. | |
1294 | */ | |
1295 | ||
1296 | static constraint inequalitySubstituteStrong (/*@returned@*/ constraint c, constraintList p) | |
1297 | { | |
1298 | DPRINTF (( message ("inequalitySubstituteStrong examining substituting for %q", constraint_print(c) ) )); | |
1299 | ||
1300 | llassert(constraint_isDefined(c) ); | |
1301 | ||
1302 | if (! (constraint_isDefined(c) ) ) | |
1303 | { | |
1304 | return c; | |
1305 | } | |
1306 | ||
1307 | if (c->ar != GTE) | |
1308 | return c; | |
1309 | ||
1310 | DPRINTF (( message ("inequalitySubstituteStrong examining substituting for %q with %q", | |
1311 | constraint_print(c), constraintList_print(p) ) )); | |
1312 | constraintList_elements (p, el) | |
1313 | { | |
1314 | ||
1315 | DPRINTF (( message ("inequalitySubstituteStrong examining substituting %s on %s", constraint_print(el), constraint_print(c) ) )); | |
1316 | ||
1317 | llassert(constraint_isDefined(el) ); | |
1318 | if ((el->ar == LT ) || (el->ar == LTE ) ) | |
1319 | { | |
1320 | constraintExpr temp2; | |
1321 | ||
1322 | if (constraintExpr_same (el->lexpr, c->expr) ) | |
1323 | { | |
1324 | DPRINTF((message ("inequalitySubstitute Replacing %s in %s with %s", | |
1325 | constraintExpr_print (c->expr), | |
1326 | constraint_print (c), | |
1327 | constraintExpr_print (el->expr) ) | |
1328 | )); | |
1329 | temp2 = constraintExpr_copy (el->expr); | |
1330 | constraintExpr_free(c->expr); | |
1331 | if ((el->ar == LTE ) ) | |
1332 | { | |
1333 | c->expr = temp2; | |
1334 | } | |
1335 | else | |
1336 | { | |
1337 | c->expr = constraintExpr_makeIncConstraintExpr (temp2); | |
1338 | } | |
1339 | } | |
1340 | ||
1341 | } | |
1342 | } | |
1343 | end_constraintList_elements; | |
1344 | ||
1345 | c = constraint_simplify(c); | |
1346 | return c; | |
1347 | } | |
1348 | ||
1349 | ||
1350 | /* This function performs substitutions based on the rule: | |
1351 | for a constraint of the form expr1 >= expr2; a < b => | |
1352 | a = b -1 for all a in expr1. This will work in most cases. | |
1353 | ||
1354 | Like inequalitySubstitute we're throwing away some information | |
1355 | */ | |
1356 | ||
1357 | static constraint inequalitySubstituteUnsound (/*@returned@*/ constraint c, constraintList p) | |
1358 | { | |
1359 | DPRINTF (( message ("Doing inequalitySubstituteUnsound " ) )); | |
1360 | ||
1361 | llassert(constraint_isDefined(c) ); | |
1362 | ||
1363 | if (c->ar != GTE) | |
1364 | return c; | |
1365 | ||
1366 | constraintList_elements (p, el) | |
1367 | { | |
1368 | ||
1369 | llassert(constraint_isDefined(el) ); | |
1370 | ||
1371 | DPRINTF (( message ("inequalitySubstituteUnsound examining substituting %s on %s", constraint_print(el), constraint_print(c) ) )); | |
1372 | if (( el->ar == LTE) || (el->ar == LT) ) | |
1373 | { | |
1374 | constraintExpr temp2; | |
1375 | ||
1376 | temp2 = constraintExpr_copy (el->expr); | |
1377 | ||
1378 | if (el->ar == LT) | |
1379 | temp2 = constraintExpr_makeDecConstraintExpr (temp2); | |
1380 | ||
1381 | DPRINTF((message ("Replacing %s in %s with %s", | |
1382 | constraintExpr_print (el->lexpr), | |
1383 | constraintExpr_print (c->lexpr), | |
1384 | constraintExpr_print (temp2) ) )); | |
1385 | ||
1386 | c->lexpr = constraintExpr_searchandreplace (c->lexpr, el->lexpr, temp2); | |
1387 | constraintExpr_free(temp2); | |
1388 | } | |
1389 | } | |
1390 | end_constraintList_elements; | |
1391 | ||
1392 | c = constraint_simplify(c); | |
1393 | return c; | |
1394 | } | |
1395 | ||
1396 | /*@only@*/ constraint constraint_substitute (/*@observer@*/ /*@temp@*/ constraint c, constraintList p) | |
1397 | { | |
1398 | constraint ret = constraint_copy (c); | |
1399 | ||
1400 | constraintList_elements (p, el) | |
1401 | { | |
1402 | if (constraint_isDefined (el)) | |
1403 | { | |
1404 | if ( el->ar == EQ) | |
1405 | if (!constraint_conflict (ret, el)) | |
1406 | { | |
1407 | constraint temp = constraint_copy(el); | |
1408 | temp = constraint_adjust(temp, ret); | |
1409 | ||
1410 | llassert(constraint_isDefined(temp) ); | |
1411 | ||
1412 | ||
1413 | DPRINTF (("constraint_substitute :: Substituting in %s using %s", | |
1414 | constraint_print (ret), constraint_print (temp))); | |
1415 | ||
1416 | ret = constraint_searchandreplace (ret, temp->lexpr, temp->expr); | |
1417 | DPRINTF (("constraint_substitute :: The new constraint is %s", constraint_print (ret)));; | |
1418 | constraint_free(temp); | |
1419 | } | |
1420 | } | |
1421 | } | |
1422 | end_constraintList_elements; | |
1423 | ||
1424 | ret = constraint_simplify (ret); | |
1425 | DPRINTF(( message (" constraint_substitute :: The final new constraint is %s", constraint_print (ret) ) )); | |
1426 | return ret; | |
1427 | } | |
1428 | ||
1429 | ||
1430 | /*@only@*/ constraintList constraintList_substituteFreeTarget (/*@only@*/ constraintList target, /*@observer@*/ constraintList subList) | |
1431 | { | |
1432 | constraintList ret; | |
1433 | ||
1434 | ret = constraintList_substitute (target, subList); | |
1435 | ||
1436 | constraintList_free(target); | |
1437 | ||
1438 | return ret; | |
1439 | } | |
1440 | ||
1441 | /* we try to do substitutions on each constraint in target using the constraint in sublist*/ | |
1442 | ||
1443 | /*@only@*/ constraintList constraintList_substitute (constraintList target,/*2observer@*/ constraintList subList) | |
1444 | { | |
1445 | ||
1446 | constraintList ret; | |
1447 | ||
1448 | ret = constraintList_makeNew(); | |
1449 | ||
1450 | constraintList_elements(target, el) | |
1451 | { | |
1452 | constraint temp; | |
1453 | /* drl possible problem : warning make sure that a side effect is not expected */ | |
1454 | ||
1455 | temp = constraint_substitute(el, subList); | |
1456 | ret = constraintList_add (ret, temp); | |
1457 | } | |
1458 | end_constraintList_elements; | |
1459 | ||
1460 | return ret; | |
1461 | } | |
1462 | ||
1463 | static constraint constraint_solve (/*@returned@*/ constraint c) | |
1464 | { | |
1465 | ||
1466 | llassert(constraint_isDefined(c) ); | |
1467 | ||
1468 | DPRINTF((message ("Solving %s\n", constraint_print(c) ) ) ); | |
1469 | c->expr = constraintExpr_solveBinaryExpr (c->lexpr, c->expr); | |
1470 | DPRINTF((message ("Solved and got %s\n", constraint_print(c) ) ) ); | |
1471 | ||
1472 | return c; | |
1473 | } | |
1474 | ||
1475 | static arithType flipAr (arithType ar) | |
1476 | { | |
1477 | switch (ar) | |
1478 | { | |
1479 | case LT: | |
1480 | return GT; | |
1481 | case LTE: | |
1482 | return GTE; | |
1483 | case EQ: | |
1484 | return EQ; | |
1485 | case GT: | |
1486 | return LT; | |
1487 | case GTE: | |
1488 | return LTE; | |
1489 | default: | |
1490 | llcontbug (message("unexpected value: case not handled")); | |
1491 | } | |
1492 | BADEXIT; | |
1493 | } | |
1494 | ||
1495 | static constraint constraint_swapLeftRight (/*@returned@*/ constraint c) | |
1496 | { | |
1497 | constraintExpr temp; | |
1498 | ||
1499 | llassert(constraint_isDefined(c) ); | |
1500 | ||
1501 | c->ar = flipAr (c->ar); | |
1502 | temp = c->lexpr; | |
1503 | c->lexpr = c->expr; | |
1504 | c->expr = temp; | |
1505 | DPRINTF(("Swaped left and right sides of constraint")); | |
1506 | return c; | |
1507 | } | |
1508 | ||
1509 | ||
1510 | ||
1511 | constraint constraint_simplify ( /*@returned@*/ constraint c) | |
1512 | { | |
1513 | ||
1514 | llassert(constraint_isDefined(c) ); | |
1515 | ||
1516 | DPRINTF(( message("constraint_simplify on %q ", constraint_print(c) ) )); | |
1517 | ||
1518 | if (constraint_tooDeep(c)) | |
1519 | { | |
1520 | DPRINTF(( message("constraint_simplify: constraint to complex aborting %q ", constraint_print(c) ) )); | |
1521 | return c; | |
1522 | ||
1523 | } | |
1524 | ||
1525 | c->lexpr = constraintExpr_simplify (c->lexpr); | |
1526 | c->expr = constraintExpr_simplify (c->expr); | |
1527 | ||
1528 | if (constraintExpr_isBinaryExpr (c->lexpr) ) | |
1529 | { | |
1530 | c = constraint_solve (c); | |
1531 | ||
1532 | c->lexpr = constraintExpr_simplify (c->lexpr); | |
1533 | c->expr = constraintExpr_simplify (c->expr); | |
1534 | } | |
1535 | ||
1536 | if (constraintExpr_isLit(c->lexpr) && (!constraintExpr_isLit(c->expr) ) ) | |
1537 | { | |
1538 | c = constraint_swapLeftRight(c); | |
1539 | /*I don't think this will be an infinate loop*/ | |
1540 | c = constraint_simplify(c); | |
1541 | } | |
1542 | ||
1543 | DPRINTF(( message("constraint_simplify returning %q ", constraint_print(c) ) )); | |
1544 | ||
1545 | return c; | |
1546 | } | |
1547 | ||
1548 | ||
1549 | ||
1550 | ||
1551 | /* returns true if fileloc for term1 is closer to file for term2 than term3*/ | |
1552 | ||
1553 | bool fileloc_closer (fileloc loc1, fileloc loc2, fileloc loc3) | |
1554 | { | |
1555 | ||
1556 | if (!fileloc_isDefined (loc1) ) | |
1557 | return FALSE; | |
1558 | ||
1559 | if (!fileloc_isDefined (loc2) ) | |
1560 | return FALSE; | |
1561 | ||
1562 | if (!fileloc_isDefined (loc3) ) | |
1563 | return TRUE; | |
1564 | ||
1565 | ||
1566 | ||
1567 | ||
1568 | if (fileloc_equal (loc2, loc3) ) | |
1569 | return FALSE; | |
1570 | ||
1571 | if (fileloc_equal (loc1, loc2) ) | |
1572 | return TRUE; | |
1573 | ||
1574 | if (fileloc_equal (loc1, loc3) ) | |
1575 | return FALSE; | |
1576 | ||
1577 | if ( fileloc_lessthan (loc1, loc2) ) | |
1578 | { | |
1579 | if (fileloc_lessthan (loc2, loc3) ) | |
1580 | { | |
1581 | llassert (fileloc_lessthan (loc1, loc3) ); | |
1582 | return TRUE; | |
1583 | } | |
1584 | else | |
1585 | { | |
1586 | return FALSE; | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | if ( !fileloc_lessthan (loc1, loc2) ) | |
1591 | { | |
1592 | if (!fileloc_lessthan (loc2, loc3) ) | |
1593 | { | |
1594 | llassert (!fileloc_lessthan (loc1, loc3) ); | |
1595 | return TRUE; | |
1596 | } | |
1597 | else | |
1598 | { | |
1599 | return FALSE; | |
1600 | } | |
1601 | } | |
1602 | ||
1603 | llassert(FALSE); | |
1604 | return FALSE; | |
1605 | } | |
1606 | ||
1607 |