X-Git-Url: http://andersk.mit.edu/gitweb/splint.git/blobdiff_plain/361091ccc3ff7e62a4817ef6400e752fef38f3c2..288cbc5cbbbb68f1c95fd491c667d34e162f7863:/src/constraintResolve.c diff --git a/src/constraintResolve.c b/src/constraintResolve.c index 2774ad9..9cbc788 100644 --- a/src/constraintResolve.c +++ b/src/constraintResolve.c @@ -1,387 +1,1482 @@ /* +** Splint - annotation-assisted static program checker +** Copyright (C) 1994-2002 University of Virginia, +** Massachusetts Institute of Technology +** +** This program is free software; you can redistribute it and/or modify it +** under the terms of the GNU General Public License as published by the +** Free Software Foundation; either version 2 of the License, or (at your +** option) any later version. +** +** This program is distributed in the hope that it will be useful, but +** WITHOUT ANY WARRANTY; without even the implied warranty of +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +** General Public License for more details. +** +** The GNU General Public License is available from http://www.gnu.org/ or +** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +** MA 02111-1307, USA. +** +** For information on splint: info@splint.org +** To report a bug: splint-bug@splint.org +** For more information: http://www.splint.org +*/ + /* +* ** constraintResolve.c */ +/* #define DEBUGPRINT 1 */ + # include /* for isdigit */ -# include "lclintMacros.nf" +# include "splintMacros.nf" # include "basic.h" # include "cgrammar.h" # include "cgrammar_tokens.h" # include "exprChecks.h" -# include "aliasChecks.h" # include "exprNodeSList.h" -# include "exprData.i" -int constraintExpr_getValue (constraintExpr expr) -{ - if (expr->expr != NULL) - { - TPRINTF( ( "Not Implemented" )); - llassert(FALSE); - } - return (constraintTerm_getValue (expr->term) ); -} +/*@access constraint, exprNode @*/ /*!!! NO! Don't do this so recklessly - design your code more carefully so you don't need to! */ -// returns 1 0 -1 like strcopy -int constraintExpr_compare (constraintExpr expr1, constraintExpr expr2) -{ - int value1, value2; +/*@-nullderef@*/ /* !!! DRL needs to fix this code! */ +/*@-nullstate@*/ /* !!! DRL needs to fix this code! */ +/*@-nullpass@*/ /* !!! DRL needs to fix this code! */ +/*@-temptrans@*/ /* !!! DRL needs to fix this code! */ - value1 = constraintExpr_getValue(expr1); - value2 = constraintExpr_getValue(expr2); - if (value1 > value2) - return 1; - if (value1 == value2) - return 0; +static constraint inequalitySubstitute (/*@returned@*/ constraint p_c, constraintList p_p); - else - return -1; -} -bool constraintExpr_canCompare (constraintExpr expr1, constraintExpr expr2) -{ - if (expr1->expr != NULL) - { - return FALSE; - } +static bool rangeCheck (arithType p_ar1, /*@observer@*/ constraintExpr p_expr1, arithType p_ar2, /*@observer@*/ constraintExpr p_expr2); - if (expr2->expr != NULL) - { - return FALSE; - } +static constraint inequalitySubstituteUnsound (/*@returned@*/ constraint p_c, constraintList p_p); - return TRUE; -} +static constraint inequalitySubstituteStrong (/*@returned@*/ constraint p_c, constraintList p_p); + +static constraint constraint_searchandreplace (/*@returned@*/ constraint p_c, constraintExpr p_old, constraintExpr p_newExpr); + + +static constraint constraint_addOr (/*@returned@*/ constraint p_orig, /*@observer@*/ constraint p_orConstr); + +static bool resolveOr (/*@temp@*/constraint p_c, /*@observer@*/ /*@temp@*/ constraintList p_list); + +static /*@only@*/ constraintList reflectChangesEnsuresFree1 (/*@only@*/ constraintList p_pre2, constraintList p_post1); -bool rangeCheck (arithType ar1, constraintExpr expr1, arithType ar2, constraintExpr expr2) +/*********************************************/ + + + +/*@only@*/ constraintList constraintList_mergeEnsuresFreeFirst (constraintList list1, constraintList list2) { - switch (ar1) - { - case GTE: - case GT: - /*irst constraint is > only > => or == cosntraint can satify it */ - if ( (ar2 == GT) || (ar2 == GTE) || (ar2 == EQ) ) - { - if (! constraintExpr_canCompare (expr1, expr2) ) - return FALSE; - - if (constraintExpr_compare (expr2, expr1) >= 0) - return TRUE; - - } - return FALSE; - default: - TPRINTF(("case not handled")); - } - return FALSE; -} + constraintList ret; + + ret = constraintList_mergeEnsures (list1, list2); -/*returns true if cosntraint post satifies cosntriant pre */ -bool satifies (constraint pre, constraint post) + constraintList_free(list1); + return ret; +} + +/*@only@*/ constraintList constraintList_mergeEnsures (constraintList list1, constraintList list2) { - if (!constraintTerm_same(pre->lexpr->term, post->lexpr->term) ) - { - return FALSE; - } - if (post->expr->expr == NULL) - return FALSE; - return rangeCheck (pre->ar, pre->expr, post->ar, post->expr); + constraintList ret; + constraintList temp; + + llassert(constraintList_isDefined(list1) ); + llassert(constraintList_isDefined(list2) ); + + DPRINTF(( message ("constraintList_mergeEnsures: list1 %s list2 %s", + constraintList_print(list1), constraintList_print(list2) + ))); - return TRUE; -} + ret = constraintList_fixConflicts (list1, list2); + ret = reflectChangesEnsuresFree1 (ret, list2); + temp = constraintList_subsumeEnsures (ret, list2); + constraintList_free(ret); + ret = temp; -constraintExpr constraintExpr_simplify (constraintExpr expr) -{ + temp = constraintList_subsumeEnsures (list2, ret); + + temp = constraintList_addList (temp, ret); + constraintList_free(ret); - expr->term = constraintTerm_simplify (expr->term); - if (expr->expr == NULL) - return expr; + DPRINTF(( message ("constraintList_mergeEnsures: returning %s ", + constraintList_print(temp) ) + )); - expr->expr = constraintExpr_simplify (expr->expr); - if ( (expr->term->constrType == INTLITERAL) && (expr->expr->term->constrType == INTLITERAL) ) - { - TPRINTF( ("EVENTUAL IMPLEMENTATION OF LITERAL MERGE " )); - TPRINTF ( (message ("Expression is %s ", constraintExpr_print (expr) ) ) ); - - if (expr->op == PLUS ) - { - TPRINTF( (message ("Adding %d and %d ", expr->term->value.intlit, - expr->expr->term->value.intlit) ) ); - expr->term->value.intlit += expr->expr->term->value.intlit; - } - else if (expr->op == MINUS ) - { - expr->term->value.intlit -= expr->expr->term->value.intlit; - } - expr->op = expr->expr->op; + return temp; +} - expr->expr = expr->expr->expr; - } - return expr; - + +/*@only@*/ constraintList constraintList_mergeRequiresFreeFirst (/*@only@*/ constraintList list1, constraintList list2) +{ + constraintList ret; + + ret = constraintList_mergeRequires(list1, list2); + + constraintList_free(list1); + + return ret; } -constraintExpr constraintExpr_add (constraintExpr e, constraintTerm term, constraintExprOp op) +/*@only@*/ constraintList constraintList_mergeRequires (constraintList list1, constraintList list2) { - constraintExpr p; + constraintList ret; + constraintList temp; - p = e; - while (p->expr != NULL) + DPRINTF((message ("constraintList_mergeRequires: merging %s and %s ", constraintList_print (list1), constraintList_print(list2) ) ) ); + + if (context_getFlag (FLG_REDUNDANTCONSTRAINTS) ) { - p = p->expr; + ret = constraintList_copy(list1); + ret = constraintList_addList(ret, list2); + return ret; } + + /* get constraints in list1 not satified by list2 */ + temp = constraintList_reflectChanges(list1, list2); + DPRINTF((message ("constraintList_mergeRequires: temp = %s", constraintList_print(temp) ) ) ); - p->op = op; - p->expr = constraintExpr_alloc(); - p->expr->term = term; +/*get constraints in list2 not satified by temp*/ + ret = constraintList_reflectChanges(list2, temp); + + DPRINTF((message ("constraintList_mergeRequires: ret = %s", constraintList_print(ret) ) ) ); + + ret = constraintList_addListFree (ret, temp); + + DPRINTF((message ("constraintList_mergeRequires: returning %s", constraintList_print(ret) ) ) ); - return e; + return ret; } -constraintExpr termMove (constraintExpr dst, constraintExpr src) +/* old name mergeResolve renamed for czech naming convention */ +void exprNode_mergeResolve (exprNode parent, exprNode child1, exprNode child2) { - constraintTerm term; - llassert (src->expr != NULL); - term = src->expr->term; - if (src->op == PLUS) - dst = constraintExpr_add (dst, term, MINUS); + constraintList temp, temp2; + + DPRINTF((message ("magically merging constraint into parent:%s for", exprNode_unparse (parent) )) ); + + DPRINTF((message (" children: %s and %s", exprNode_unparse (child1), exprNode_unparse(child2) ) ) ); + + if (exprNode_isError (child1) || exprNode_isError(child2) ) + { + if (exprNode_isError (child1) && !exprNode_isError(child2) ) + { + constraintList_free(parent->requiresConstraints); + + parent->requiresConstraints = constraintList_copy (child2->requiresConstraints); + constraintList_free(parent->ensuresConstraints); + + parent->ensuresConstraints = constraintList_copy (child2->ensuresConstraints); + DPRINTF((message ("Copied child constraints: pre: %s and post: %s", + constraintList_print( child2->requiresConstraints), + constraintList_print (child2->ensuresConstraints) + ) + )); + return; + } + else + { + llassert(exprNode_isError(child2) ); + return; + } + } + + llassert(!exprNode_isError (child1) && ! exprNode_isError(child2) ); + + DPRINTF((message ("Child constraints are %s %s and %s %s", + constraintList_print (child1->requiresConstraints), + constraintList_print (child1->ensuresConstraints), + constraintList_print (child2->requiresConstraints), + constraintList_print (child2->ensuresConstraints) + ) ) ); + + + constraintList_free(parent->requiresConstraints); + + parent->requiresConstraints = constraintList_copy (child1->requiresConstraints); + + if ( context_getFlag (FLG_ORCONSTRAINT) ) + temp = constraintList_reflectChangesOr (child2->requiresConstraints, child1->ensuresConstraints); else - if (src->op == MINUS) - dst = constraintExpr_add (dst, term, PLUS); + temp = constraintList_reflectChanges(child2->requiresConstraints, child1->ensuresConstraints); + + temp2 = constraintList_mergeRequires (parent->requiresConstraints, temp); + constraintList_free(parent->requiresConstraints); + constraintList_free(temp); - return dst; -} + parent->requiresConstraints = temp2; -constraint solveforterm (constraint c) -{ - constraintExpr p; - p = c->lexpr; - while (p->expr != NULL) - { - TPRINTF( (message("Moving %s", constraintExpr_print (c->expr) ) ) ); - c->expr = termMove(c->expr, p); - p->op = p->expr->op; - #warning memleak + DPRINTF((message ("Parent requires constraints are %s ", + constraintList_print (parent->requiresConstraints) + ) ) ); - p->expr = p->expr->expr; - } - return c; -} + constraintList_free(parent->ensuresConstraints); -constraint constraint_simplify (constraint c) -{ - c = solveforterm (c); - c->lexpr = constraintExpr_simplify (c->lexpr); - c->expr = constraintExpr_simplify (c->expr); - return c; + parent->ensuresConstraints = constraintList_mergeEnsures(child1->ensuresConstraints, + child2->ensuresConstraints); + + + DPRINTF((message ("Parent constraints are %s and %s ", + constraintList_print (parent->requiresConstraints), + constraintList_print (parent->ensuresConstraints) + ) ) ); + } -bool resolve (constraint c, constraintList p) + + + +/*@only@*/ constraintList constraintList_subsumeEnsures (constraintList list1, constraintList list2) { - constraintList_elements (p, el) + constraintList ret; + ret = constraintList_makeNew(); + constraintList_elements (list1, el) { - if ( satifies (c, el) ) + + DPRINTF ((message ("Examining %s", constraint_print (el) ) ) ); + if (!constraintList_resolve (el, list2) ) { - TPRINTF ( (message ("\n%s Satifies %s\n ", constraint_print(el), constraint_print(c) ) ) ); - return TRUE; + constraint temp; + temp = constraint_copy(el); + ret = constraintList_add (ret, temp); } - } - end_constraintList_elements; - TPRINTF ( (message ("no constraints satify %s", constraint_print(c) ) )); - return FALSE; -} - -constraint substitute (constraint c, constraintList p) -{ - constraintList_elements (p, el) - { - if (constraintTerm_same(c->lexpr->term, el->lexpr->term) ) + else { - if ( el->ar == EQ) - { - c->lexpr = constraintExpr_copy (el->expr); - c = constraint_simplify(c); - return c; - } + DPRINTF ((message ("Subsuming %s", constraint_print (el) ) ) ); } - } - end_constraintList_elements; + } end_constraintList_elements; - c = constraint_simplify(c); - return c; + return ret; } + + +/*used to be reflectChangesFreePre renamed for Czech naming conventino*/ +/* tries to resolve constraints in list pre2 using post1 */ +/*@only@*/ constraintList constraintList_reflectChangesFreePre (/*@only@*/ constraintList pre2, /*@observer@*/ constraintList post1) +{ + constraintList ret; + + ret = constraintList_reflectChanges(pre2, post1); + + constraintList_free (pre2); -constraintList reflectChanges (constraintList pre2, constraintList post1) + return ret; +} + + + +/* tries to resolve constraints in list pre2 using post1 */ + +static /*@only@*/ constraintList reflectChangesNoOr (/*@observer@*/ /*@temp@*/ constraintList pre2, /*@observer@*/ /*@temp@*/ constraintList post1) { constraintList ret; constraint temp; - ret = constraintList_new(); + constraint temp2; + + llassert (! context_getFlag (FLG_ORCONSTRAINT) ); + + ret = constraintList_makeNew(); + DPRINTF((message ("reflectChanges: lists %s and %s", constraintList_print(pre2), constraintList_print(post1) ))); + constraintList_elements (pre2, el) { - if (!resolve (el, post1) ) + if (!constraintList_resolve (el, post1) ) { - temp = substitute (el, post1); - ret = constraintList_add (ret, temp); + temp = constraint_substitute (el, post1); + if (!constraintList_resolve (temp, post1) ) + { + /* try inequality substitution + the inequality substitution may cause us to lose information + so we don't want to store the result but we do it anyway + */ + temp2 = constraint_copy (temp); + temp2 = inequalitySubstitute (temp2, post1); + if (!constraintList_resolve (temp2, post1) ) + { + temp2 = inequalitySubstituteUnsound (temp2, post1); + if (!constraintList_resolve (temp2, post1) ) + ret = constraintList_add (ret, temp2); + else + constraint_free(temp2); + } + else + { + constraint_free(temp2); + } + } + constraint_free(temp); } } end_constraintList_elements; + DPRINTF((message ("reflectChanges: returning %s", constraintList_print(ret) ) ) ); return ret; } - -/*check if rvalue side has term*/ -bool constraintExpr_hasTerm (constraint c, constraintTerm term) +/* tries to resolve constraints in list pre2 using post1 */ +/*@only@*/ constraintList constraintList_reflectChanges(/*@observer@*/ constraintList pre2, /*@observer@*/ constraintList post1) { - constraintExpr p; - p = c->expr; - while (p != NULL) - { - if (constraintTerm_same (p->term, term) ) - return TRUE; + constraintList temp; + + if ( context_getFlag (FLG_ORCONSTRAINT) ) + + temp = constraintList_reflectChangesOr (pre2, post1); + else + temp = reflectChangesNoOr(pre2, post1); - p = p->expr->expr; - } - TPRINTF(( - message ("constraintExpr_hasTerm returned fallse for %s %S", - constraint_print(c), constraintTerm_print(term) - ) - )); - return FALSE; + return temp; } -constraintExpr solveEq (constraint c, constraintTerm t) +static constraint constraint_addOr (/*@returned@*/ constraint orig, /*@observer@*/ constraint orConstr) { - constraintExpr p; - c = constraint_copy (c); - TPRINTF(("\ndoing solveEq\n")); - if (! constraintTerm_same (c->expr->term, t) ) - { - TPRINTF ( (message ("\n\nconstraintTerms: %s %s not same ", constraintTerm_print(c->expr->term), - constraintTerm_print(t) ) - ) ); - return NULL; - } + constraint c; + c = orig; - p = c->expr; - while (p->expr != NULL) + DPRINTF((message("constraint_addor: oring %s onto %s", constraint_printOr(orConstr), constraint_printOr(orig) ) )); + + while (c->or != NULL) { - TPRINTF( (message("\n\nMoving %s", constraintExpr_print (c->expr) ) ) ); - c->lexpr = termMove(c->lexpr, p); - p->expr = p->expr->expr; + c = c->or; } - return c->lexpr; + c->or = constraint_copy(orConstr); + + DPRINTF((message("constraint_addor: returning %s",constraint_printOr(orig) ) )); + return orig; } -constraint updateConstraint (constraint c, constraintList p) + +static bool resolveOr ( /*@temp@*/ constraint c, /*@observer@*/ /*@temp@*/ constraintList list) { - TPRINTF(("start updateConstraints")); - constraintList_elements (p, el) + constraint temp; + + int numberOr; + + numberOr = 0; + DPRINTF(( message("resolveOr: constraint %s and list %s", constraint_printOr(c), constraintList_print(list) ) )); + temp = c; + + do + { + if (constraintList_resolve (temp, list) ) + return TRUE; + temp = temp->or; + numberOr++; + llassert(numberOr <= 10); + } + while (constraint_isDefined(temp)); + + return FALSE; +} + +/*This is a "helper" function for doResolveOr */ + +static /*@only@*/ constraint doResolve (/*@only@*/ constraint c, constraintList post1, bool * resolved) +{ + constraint temp; + + llassert(constraint_isUndefined (c->or ) ); + + if (!resolveOr (c, post1) ) { - if (constraintTerm_same(c->lexpr->term, el->lexpr->term) ) + temp = constraint_substitute (c, post1); + + if (!resolveOr (temp, post1) ) { - TPRINTF(("")); - if ( el->ar == EQ) - { - TPRINTF(("")); + /* try inequality substitution */ + constraint temp2; + + /* the inequality substitution may cause us to lose information + so we don't want to store the result but we do anyway + */ + temp2 = constraint_copy (c); + temp2 = inequalitySubstitute (temp2, post1); - if (constraintExpr_hasTerm (el, c->lexpr->term) ) + if (!resolveOr (temp2, post1) ) + { + constraint temp3; + temp3 = constraint_copy(temp2); + + temp3 = inequalitySubstituteStrong (temp3, post1); + if (!resolveOr (temp3, post1) ) { - constraintExpr solve; - TPRINTF(("")); - solve = solveEq (el, c->lexpr->term); - if (solve) - { - c->lexpr = constraintExpr_copy (solve); - c = constraint_simplify(c); - return c; + temp2 = inequalitySubstituteUnsound (temp2, post1); + if (!resolveOr (temp2, post1) ) + { + if (!constraint_same (temp, temp2) ) + temp = constraint_addOr (temp, temp2); + + if (!constraint_same (temp, temp3) && !constraint_same (temp3, temp2) ) + temp = constraint_addOr (temp, temp3); + + *resolved = FALSE; + + constraint_free(temp2); + constraint_free(temp3); + constraint_free(c); + + return temp; } + constraint_free(temp2); + constraint_free(temp3); + } + else + { + constraint_free(temp2); + constraint_free(temp3); } } + else + { + constraint_free(temp2); + } + } + constraint_free(temp); } - end_constraintList_elements; - c = constraint_simplify(c); + constraint_free(c); - TPRINTF(("end updateConstraints")); - return c; + /*drl bee: pbr*/ *resolved = TRUE; + return NULL; +} + +static /*@only@*/ constraint doResolveOr (/*@observer@*/ /*@temp@*/ constraint c, constraintList post1, /*@out@*/bool * resolved) +{ + constraint ret; + constraint next; + constraint curr; + + + DPRINTF(( message("doResolveOr: constraint %s and list %s", constraint_printOr(c), constraintList_print(post1) ) )); + + + + /*drl bee: pbr*/ *resolved = FALSE; + + + ret = constraint_copy(c); + + if (constraintList_isEmpty(post1) ) + { + return ret; + } + + next = ret->or; + ret->or = NULL; + + ret = doResolve (ret, post1, resolved); + + if (*resolved) + { + if (next != NULL) + constraint_free(next); + + /*we don't need to free ret when resolved is false because ret is null*/ + llassert(ret == NULL); + + return NULL; + } + + while (next != NULL) + { + curr = next; + next = curr->or; + curr->or = NULL; + + curr = doResolve (curr, post1, resolved); + + /*drl bee: pbr*/ if (*resolved) + { + /* curr is null so we don't try to free it*/ + llassert(curr == NULL); + + if (next != NULL) + constraint_free(next); + + constraint_free(ret); + return NULL; + } + ret = constraint_addOr (ret, curr); + constraint_free(curr); + } + return ret; } +/* tries to resolve constraints in list pr2 using post1 */ +/*@only@*/ constraintList constraintList_reflectChangesOr (constraintList pre2, constraintList post1) +{ + bool resolved; + constraintList ret; + constraint temp; + ret = constraintList_makeNew(); + DPRINTF((message ("constraintList_reflectChangesOr: lists %s and %s", constraintList_print(pre2), constraintList_print(post1) ))); + + constraintList_elements (pre2, el) + { + temp = doResolveOr (el, post1, &resolved); + + if (!resolved) + { + ret = constraintList_add(ret, temp); + } + else + { + /* we don't need to free temp when + resolved is false because temp is null */ + llassert(temp == NULL); + } + + } end_constraintList_elements; + + DPRINTF((message ("constraintList_reflectChangesOr: returning %s", constraintList_print(ret) ) ) ); + return ret; +} -constraintList reflectChangesEnsures (constraintList pre2, constraintList post1) +static /*@only@*/ constraintList reflectChangesEnsures (/*@observer@*/ constraintList pre2, constraintList post1) { constraintList ret; constraint temp; - ret = constraintList_new(); + ret = constraintList_makeNew(); constraintList_elements (pre2, el) { - if (!resolve (el, post1) ) + if (!constraintList_resolve (el, post1) ) { - temp = updateConstraint (el, post1); - if (temp != NULL) + temp = constraint_substitute (el, post1); + llassert (temp != NULL); + + if (!constraintList_resolve (temp, post1) ) ret = constraintList_add (ret, temp); + else + constraint_free(temp); + } + else + { + DPRINTF ((message ("Resolved away %s ", constraint_print(el) ) ) ); } } end_constraintList_elements; return ret; } -void mergeResolve (exprNode parent, exprNode child1, exprNode child2) + +static /*@only@*/ constraintList reflectChangesEnsuresFree1 (/*@only@*/ constraintList pre2, constraintList post1) { - constraintList temp; - TPRINTF( (message ("magically merging constraint into parent:%s for children: %s and %s", exprNode_unparse (parent), exprNode_unparse (child1), exprNode_unparse(child2) ) - ) ); - llassert (!exprNode_isError (child1) || !exprNode_isError(child2) ); - if (exprNode_isError (child1) ) - { - parent->requiresConstraints = constraintList_copy (child2->requiresConstraints); - parent->ensuresConstraints = constraintList_copy (child2->ensuresConstraints); - DPRINTF((message ("Copied child constraints: pre: %s and post: %s ", - constraintList_print( child2->requiresConstraints), - constraintList_print (child2->ensuresConstraints) - ) - )); - return; - } + constraintList ret; - llassert(!exprNode_isError(child2) ); + ret = reflectChangesEnsures (pre2, post1); - TPRINTF( (message ("Child constraints are %s and %s ", - constraintList_print (child1->requiresConstraints), - constraintList_print (child2->requiresConstraints) - ) ) ); - - parent->requiresConstraints = constraintList_new(); - parent->ensuresConstraints = constraintList_new(); + constraintList_free(pre2); - parent->requiresConstraints = constraintList_copy (child1->requiresConstraints); - - temp = reflectChanges (child2->requiresConstraints, child1->ensuresConstraints); - parent->requiresConstraints = constraintList_addList (parent->requiresConstraints, temp); + return ret; +} - - temp = reflectChangesEnsures (child1->ensuresConstraints, child2->ensuresConstraints); - // temp = constraintList_copy (child1->ensuresConstraints); +static bool constraint_conflict (constraint c1, constraint c2) +{ - parent->ensuresConstraints = constraintList_copy (child2->ensuresConstraints); - parent->ensuresConstraints = constraintList_addList (parent->ensuresConstraints, temp); + if (constraintExpr_similar(c1->lexpr, c2->lexpr) ) + { + if (c1->ar == EQ) + if (c1->ar == c2->ar) + { + DPRINTF ((message ("%s conflicts with %s ", constraint_print (c1), constraint_print(c2) ) ) ); + return TRUE; + } + } + + /* This is a slight kludg to prevent circular constraints like + strlen(str) == maxRead(s) + strlen(str); + */ + + /*@i324234*/ /* clean this up */ - TPRINTF( (message ("Parent constraints are %s and %s ", - constraintList_print (parent->requiresConstraints), - constraintList_print (parent->ensuresConstraints) - ) ) ); - + if (c1->ar == EQ) + if (c1->ar == c2->ar) + { + if (constraintExpr_search (c1->lexpr, c2->expr) ) + if (constraintExpr_isTerm(c1->lexpr) ) + { + constraintTerm term; + + term = constraintExpr_getTerm(c1->lexpr); + + if (constraintTerm_isExprNode(term) ) + { + DPRINTF ((message ("%s conflicts with %s ", constraint_print (c1), constraint_print(c2) ) ) ); + return TRUE; + } + } + } + + if (constraint_tooDeep(c1) || constraint_tooDeep(c2) ) + { + DPRINTF ((message ("%s conflicts with %s (constraint is too deep", constraint_print (c1), constraint_print(c2) ) ) ); + return TRUE; + } + + DPRINTF ((message ("%s doesn't conflict with %s ", constraint_print (c1), constraint_print(c2) ) ) ); + + return FALSE; + +} + +static void constraint_fixConflict (/*@temp@*/ constraint good, /*@temp@*/ /*@observer@*/ constraint conflicting) /*@modifies good@*/ +{ + if (conflicting->ar ==EQ ) + { + good->expr = constraintExpr_searchandreplace (good->expr, conflicting->lexpr, conflicting->expr); + good = constraint_simplify (good); + } + + +} + +static bool conflict (constraint c, constraintList list) +{ + + constraintList_elements (list, el) + { + if ( constraint_conflict(el, c) ) + { + constraint_fixConflict (el, c); + return TRUE; + } + } end_constraintList_elements; + + return FALSE; + +} + +/* + check if constraint in list1 conflicts with constraints in List2. If so we + remove form list1 and change list2. +*/ + +constraintList constraintList_fixConflicts (constraintList list1, constraintList list2) +{ + constraintList ret; + ret = constraintList_makeNew(); + llassert(constraintList_isDefined(list1) ); + constraintList_elements (list1, el) + { + if (! conflict (el, list2) ) + { + constraint temp; + temp = constraint_copy(el); + ret = constraintList_add (ret, temp); + } + } end_constraintList_elements; + + return ret; +} + +/*returns true if constraint post satifies cosntriant pre */ +static bool satifies (constraint pre, constraint post) +{ + if (constraint_isAlwaysTrue (pre) ) + return TRUE; + + if (!constraintExpr_similar (pre->lexpr, post->lexpr) ) + { + return FALSE; + } + if (constraintExpr_isUndefined(post->expr)) + { + llassert(FALSE); + return FALSE; + } + + return rangeCheck (pre->ar, pre->expr, post->ar, post->expr); +} + + +bool constraintList_resolve (/*@temp@*/ /*@observer@*/ constraint c, /*@temp@*/ /*@observer@*/ constraintList p) +{ + constraintList_elements (p, el) + { + if ( satifies (c, el) ) + { + DPRINTF ((message ("\n%s Satifies %s\n ", constraint_print(el), constraint_print(c) ) ) ); + return TRUE; + } + DPRINTF ((message ("\n%s does not satify %s\n ", constraint_print(el), constraint_print(c) ) ) ); + } + end_constraintList_elements; + DPRINTF ((message ("no constraints satify %s", constraint_print(c) ) )); + return FALSE; +} + +static bool arithType_canResolve (arithType ar1, arithType ar2) +{ + switch (ar1) + { + case GTE: + case GT: + if ((ar2 == GT) || (ar2 == GTE) || (ar2 == EQ) ) + { + return TRUE; + } + break; + + case EQ: + if (ar2 == EQ) + return TRUE; + break; + + case LT: + case LTE: + if ((ar2 == LT) || (ar2 == LTE) || (ar2 == EQ) ) + return TRUE; + break; + default: + return FALSE; + } + return FALSE; +} + +/*checks for the case expr2 == sizeof buf1 and buf1 is a fixed array*/ +static bool sizeofBufComp(constraintExpr buf1, constraintExpr expr2) +{ + constraintTerm ct; + exprNode e, t; + sRef s1, s2; + /*@access constraintExpr@*/ + + if ((expr2->kind != term) && (buf1->kind != term) ) + return FALSE; + + + ct = constraintExprData_termGetTerm(expr2->data); + + if (!constraintTerm_isExprNode(ct) ) + return FALSE; + + e = constraintTerm_getExprNode(ct); + + if (e->kind != XPR_SIZEOF) + return FALSE; + + t = exprData_getSingle (e->edata); + s1 = exprNode_getSref (t); + + s2 = constraintTerm_getsRef(constraintExprData_termGetTerm(buf1->data) ); + + /*@i223@*/ /*this may be the wronge thing to test for */ + if (sRef_similarRelaxed(s1, s2) || sRef_sameName (s1, s2) ) + { + /*@i22*/ /* get rid of this test of now */ + /* if (ctype_isFixedArray (sRef_getType (s2) ) ) */ + return TRUE; + } + return FALSE; +} + +/* look for the special case of + maxSet(buf) >= sizeof(buf) - 1 +*/ + +/*@i223@*/ /*need to add some type checking */ +static bool sizeOfMaxSet( /*@observer@*/ /*@temp@*/ constraint c) +{ + constraintExpr l, r, buf1, buf2, con; + + DPRINTF(( message("sizeOfMaxSet: checking %s ", constraint_print(c) ) + )); + + l = c->lexpr; + r = c->expr; + + if (!((c->ar == EQ) || (c->ar == GTE) || (c->ar == LTE) ) ) + return FALSE; + + /*check if the constraintExpr is MaxSet(buf) */ + if (l->kind == unaryExpr) + { + if (constraintExprData_unaryExprGetOp(l->data) == MAXSET) + { + buf1 = constraintExprData_unaryExprGetExpr(l->data); + } + else + return FALSE; + } + else + return FALSE; + + + if (r->kind != binaryexpr) + return FALSE; + + buf2 = constraintExprData_binaryExprGetExpr1(r->data); + con = constraintExprData_binaryExprGetExpr2(r->data); + + if (constraintExprData_binaryExprGetOp(r->data) == BINARYOP_MINUS) + { + if (constraintExpr_canGetValue(con) ) + { + long i; + + i = constraintExpr_getValue(con); + if (i != 1) + { + return FALSE; + } + } + else + return FALSE; + } + + if (constraintExprData_binaryExprGetOp(r->data) == BINARYOP_PLUS) + { + if (constraintExpr_canGetValue(con) ) + { + long i; + + i = constraintExpr_getValue(con); + if (i != -1) + { + return FALSE; + } + } + else + return FALSE; + } + + if (sizeofBufComp(buf1, buf2)) + { + return TRUE; + } + else + { + return FALSE; + } + + +} +/*@noaccess constraintExpr@*/ + +/* We look for constraint which are tautologies */ + +bool constraint_isAlwaysTrue (/*@observer@*/ /*@temp@*/ constraint c) +{ + constraintExpr l, r; + bool rHasConstant; + int rConstant; + + l = c->lexpr; + r = c->expr; + + DPRINTF(( message("constraint_IsAlwaysTrue:examining %s", constraint_print(c) ) )); + + if (sizeOfMaxSet(c) ) + return TRUE; + + if (constraintExpr_canGetValue(l) && constraintExpr_canGetValue(r) ) + { + int cmp; + cmp = constraintExpr_compare (l, r); + switch (c->ar) + { + case EQ: + return (cmp == 0); + case GT: + return (cmp > 0); + case GTE: + return (cmp >= 0); + case LTE: + return (cmp <= 0); + case LT: + return (cmp < 0); + + default: + BADEXIT; + /*@notreached@*/ + break; + } + } + + if (constraintExpr_similar (l,r) ) + { + switch (c->ar) + { + case EQ: + case GTE: + case LTE: + return TRUE; + + case GT: + case LT: + break; + default: + BADEXIT; + /*@notreached@*/ + break; + } + } + + l = constraintExpr_copy (c->lexpr); + r = constraintExpr_copy (c->expr); + + r = constraintExpr_propagateConstants (r, &rHasConstant, &rConstant); + + if (constraintExpr_similar (l,r) && (rHasConstant ) ) + { + DPRINTF(( message("constraint_IsAlwaysTrue: after removing constants %s and %s are similar", constraintExpr_unparse(l), constraintExpr_unparse(r) ) )); + DPRINTF(( message("constraint_IsAlwaysTrue: rconstant is %d", rConstant ) )); + + constraintExpr_free(l); + constraintExpr_free(r); + + switch (c->ar) + { + case EQ: + return (rConstant == 0); + case LT: + return (rConstant > 0); + case LTE: + return (rConstant >= 0); + case GTE: + return (rConstant <= 0); + case GT: + return (rConstant < 0); + + default: + BADEXIT; + /*@notreached@*/ + break; + } + } + else + { + constraintExpr_free(l); + constraintExpr_free(r); + DPRINTF(( message("Constraint %s is not always true", constraint_print(c) ) )); + return FALSE; + } + + BADEXIT; +} + +static bool rangeCheck (arithType ar1, /*@observer@*/ constraintExpr expr1, arithType ar2, /*@observer@*/ constraintExpr expr2) + +{ + DPRINTF ((message ("Doing Range CHECK %s and %s", constraintExpr_unparse(expr1), constraintExpr_unparse(expr2) ) )); + + if (! arithType_canResolve (ar1, ar2) ) + return FALSE; + + switch (ar1) + { + case GTE: + if (constraintExpr_similar (expr1, expr2) ) + return TRUE; + /*@fallthrough@*/ + case GT: + if (! (constraintExpr_canGetValue (expr1) && + constraintExpr_canGetValue (expr2) ) ) + { + constraintExpr e1, e2; + bool p1, p2; + int const1, const2; + + e1 = constraintExpr_copy(expr1); + e2 = constraintExpr_copy(expr2); + + e1 = constraintExpr_propagateConstants (e1, &p1, &const1); + + e2 = constraintExpr_propagateConstants (e2, &p2, &const2); + + if (p1 || p2) + { + if (!p1) + const1 = 0; + + if (!p2) + const2 = 0; + + if (const1 <= const2) + if (constraintExpr_similar (e1, e2) ) + { + constraintExpr_free(e1); + constraintExpr_free(e2); + return TRUE; + } + } + DPRINTF(("Can't Get value")); + + constraintExpr_free(e1); + constraintExpr_free(e2); + return FALSE; + } + + if (constraintExpr_compare (expr2, expr1) >= 0) + return TRUE; + + return FALSE; + case EQ: + if (constraintExpr_similar (expr1, expr2) ) + return TRUE; + + return FALSE; + case LTE: + if (constraintExpr_similar (expr1, expr2) ) + return TRUE; + /*@fallthrough@*/ + case LT: + if (! (constraintExpr_canGetValue (expr1) && + constraintExpr_canGetValue (expr2) ) ) + { + constraintExpr e1, e2; + bool p1, p2; + int const1, const2; + + e1 = constraintExpr_copy(expr1); + e2 = constraintExpr_copy(expr2); + + e1 = constraintExpr_propagateConstants (e1, &p1, &const1); + + e2 = constraintExpr_propagateConstants (e2, &p2, &const2); + + if (p1 || p2) + { + if (!p1) + const1 = 0; + + if (!p2) + const2 = 0; + + if (const1 >= const2) + if (constraintExpr_similar (e1, e2) ) + { + constraintExpr_free(e1); + constraintExpr_free(e2); + return TRUE; + } + } + constraintExpr_free(e1); + constraintExpr_free(e2); + + DPRINTF(("Can't Get value")); + return FALSE; + } + + if (constraintExpr_compare (expr2, expr1) <= 0) + return TRUE; + + return FALSE; + + default: + llcontbug((message("Unhandled case in switch: %q", arithType_print(ar1) ) ) ); + } + BADEXIT; +} + +static constraint constraint_searchandreplace (/*@returned@*/ constraint c, constraintExpr old, constraintExpr newExpr) +{ + DPRINTF (("Doing replace for lexpr") ); + c->lexpr = constraintExpr_searchandreplace (c->lexpr, old, newExpr); + DPRINTF (("Doing replace for expr") ); + c->expr = constraintExpr_searchandreplace (c->expr, old, newExpr); + return c; +} + +bool constraint_search (constraint c, constraintExpr old) /*@*/ +{ + bool ret; + ret = FALSE; + + ret = constraintExpr_search (c->lexpr, old); + ret = ret || constraintExpr_search (c->expr, old); + return ret; +} + +/* adjust file locs and stuff */ +static constraint constraint_adjust (/*@returned@*/ constraint substitute, /*@observer@*/ constraint old) +{ + fileloc loc1, loc2, loc3; + + DPRINTF ((message("Start adjust on %s and %s", constraint_print(substitute), + constraint_print(old)) + )); + + loc1 = constraint_getFileloc (old); + loc2 = constraintExpr_getFileloc (substitute->lexpr); + loc3 = constraintExpr_getFileloc (substitute->expr); + + /* special case of an equality that "contains itself" */ + if (constraintExpr_search (substitute->expr, substitute->lexpr) ) + if (fileloc_closer (loc1, loc3, loc2)) + { + constraintExpr temp; + DPRINTF ((message("Doing adjust on %s", constraint_print(substitute) ) + )); + temp = substitute->lexpr; + substitute->lexpr = substitute->expr; + substitute->expr = temp; + substitute = constraint_simplify(substitute); + } + + fileloc_free (loc1); + fileloc_free (loc2); + fileloc_free (loc3); + + return substitute; + +} + +/* If function preforms substitutes based on inequality + + It uses the rule x >= y && b < y ===> x >= b + 1 + + Warning this is sound but throws out information + */ + +constraint inequalitySubstitute (/*@returned@*/ constraint c, constraintList p) +{ + if (c->ar != GTE) + return c; + + constraintList_elements (p, el) + { + if ((el->ar == LT ) ) + /* if (!constraint_conflict (c, el) ) */ /*@i523 explain this! */ + { + constraintExpr temp2; + + /*@i22*/ + + if (constraintExpr_same (el->expr, c->expr) ) + { + DPRINTF((message ("inequalitySubstitute Replacing %q in %q with %q", + constraintExpr_print (c->expr), + constraint_print (c), + constraintExpr_print (el->expr) ) + )); + temp2 = constraintExpr_copy (el->lexpr); + constraintExpr_free(c->expr); + c->expr = constraintExpr_makeIncConstraintExpr (temp2); + + } + + } + } + end_constraintList_elements; + + c = constraint_simplify(c); + return c; +} + + +/* drl7x 7/26/001 + + THis function is like inequalitySubstitute but it adds the rule + added the rules x >= y && y <= b ===> x >= b + x >= y && y < b ===> x >= b + 1 + + This is sound but sonce it throws out additional information it should only one used + if we're oring constraints. + */ + +static constraint inequalitySubstituteStrong (/*@returned@*/ constraint c, constraintList p) +{ + DPRINTF (( message ("inequalitySubstituteStrong examining substituting for %q", constraint_print(c) ) )); + + if (c->ar != GTE) + return c; + + DPRINTF (( message ("inequalitySubstituteStrong examining substituting for %q with %q", + constraint_print(c), constraintList_print(p) ) )); + constraintList_elements (p, el) + { + DPRINTF (( message ("inequalitySubstituteStrong examining substituting %s on %s", constraint_print(el), constraint_print(c) ) )); + + if ((el->ar == LT ) || (el->ar == LTE ) ) + /* if (!constraint_conflict (c, el) ) */ /*@i523@*/ + { + constraintExpr temp2; + + /*@i22*/ + + if (constraintExpr_same (el->lexpr, c->expr) ) + { + DPRINTF((message ("inequalitySubstitute Replacing %s in %s with %s", + constraintExpr_print (c->expr), + constraint_print (c), + constraintExpr_print (el->expr) ) + )); + temp2 = constraintExpr_copy (el->expr); + constraintExpr_free(c->expr); + if ((el->ar == LTE ) ) + { + c->expr = temp2; + } + else + { + c->expr = constraintExpr_makeIncConstraintExpr (temp2); + } + } + + } + } + end_constraintList_elements; + + c = constraint_simplify(c); + return c; +} + + +/* This function performs substitutions based on the rule: + for a constraint of the form expr1 >= expr2; a < b => + a = b -1 for all a in expr1. This will work in most cases. + + Like inequalitySubstitute we're throwing away some information +*/ + +static constraint inequalitySubstituteUnsound (/*@returned@*/ constraint c, constraintList p) +{ + DPRINTF (( message ("Doing inequalitySubstituteUnsound " ) )); + + if (c->ar != GTE) + return c; + + constraintList_elements (p, el) + { + DPRINTF (( message ("inequalitySubstituteUnsound examining substituting %s on %s", constraint_print(el), constraint_print(c) ) )); + if (( el->ar == LTE) || (el->ar == LT) ) + /* if (!constraint_conflict (c, el) ) */ /*@i532@*/ + { + constraintExpr temp2; + + temp2 = constraintExpr_copy (el->expr); + + if (el->ar == LT) + temp2 = constraintExpr_makeDecConstraintExpr (temp2); + + DPRINTF((message ("Replacing %s in %s with %s", + constraintExpr_print (el->lexpr), + constraintExpr_print (c->lexpr), + constraintExpr_print (temp2) ) )); + + c->lexpr = constraintExpr_searchandreplace (c->lexpr, el->lexpr, temp2); + constraintExpr_free(temp2); + } + } + end_constraintList_elements; + + c = constraint_simplify(c); + return c; +} + +/*@only@*/ constraint constraint_substitute (/*@observer@*/ /*@temp@*/ constraint c, constraintList p) +{ + constraint ret; + + ret = constraint_copy(c); + constraintList_elements (p, el) + { + if ( el->ar == EQ) + if (!constraint_conflict (ret, el) ) + + { + constraint temp; + + temp = constraint_copy(el); + + temp = constraint_adjust(temp, ret); + + DPRINTF((message ("Substituting %s in the constraint %s", + constraint_print (temp), constraint_print (ret) + ) ) ); + + + ret = constraint_searchandreplace (ret, temp->lexpr, temp->expr); + DPRINTF(( message ("The new constraint is %s", constraint_print (ret) ) )); + constraint_free(temp); + } + } + end_constraintList_elements; + DPRINTF(( message ("The finial new constraint is %s", constraint_print (ret) ) )); + + ret = constraint_simplify(ret); + return ret; +} + + +/*@only@*/ constraintList constraintList_substituteFreeTarget (/*@only@*/ constraintList target, /*@observer@*/ constraintList subList) +{ +constraintList ret; + +ret = constraintList_substitute (target, subList); + +constraintList_free(target); + +return ret; +} + +/* we try to do substitutions on each constraint in target using the constraint in sublist*/ + +/*@only@*/ constraintList constraintList_substitute (constraintList target,/*2observer@*/ constraintList subList) +{ + + constraintList ret; + + ret = constraintList_makeNew(); + + constraintList_elements(target, el) + { + constraint temp; + /* drl possible problem : warning make sure that a side effect is not expected */ + + temp = constraint_substitute(el, subList); + ret = constraintList_add (ret, temp); + } + end_constraintList_elements; + + return ret; +} + +static constraint constraint_solve (/*@returned@*/ constraint c) +{ + DPRINTF((message ("Solving %s\n", constraint_print(c) ) ) ); + c->expr = constraintExpr_solveBinaryExpr (c->lexpr, c->expr); + DPRINTF((message ("Solved and got %s\n", constraint_print(c) ) ) ); + + return c; +} + +static arithType flipAr (arithType ar) +{ + switch (ar) + { + case LT: + return GT; + case LTE: + return GTE; + case EQ: + return EQ; + case GT: + return LT; + case GTE: + return LTE; + default: + llcontbug (message("unexpected value: case not handled")); + } + BADEXIT; +} + +static constraint constraint_swapLeftRight (/*@returned@*/ constraint c) +{ + constraintExpr temp; + c->ar = flipAr (c->ar); + temp = c->lexpr; + c->lexpr = c->expr; + c->expr = temp; + DPRINTF(("Swaped left and right sides of constraint")); + return c; +} + + + +constraint constraint_simplify ( /*@returned@*/ constraint c) +{ + + DPRINTF(( message("constraint_simplify on %q ", constraint_print(c) ) )); + + if (constraint_tooDeep(c)) + { + DPRINTF(( message("constraint_simplify: constraint to complex aborting %q ", constraint_print(c) ) )); + return c; + + } + + c->lexpr = constraintExpr_simplify (c->lexpr); + c->expr = constraintExpr_simplify (c->expr); + + if (constraintExpr_isBinaryExpr (c->lexpr) ) + { + c = constraint_solve (c); + + c->lexpr = constraintExpr_simplify (c->lexpr); + c->expr = constraintExpr_simplify (c->expr); + } + + if (constraintExpr_isLit(c->lexpr) && (!constraintExpr_isLit(c->expr) ) ) + { + c = constraint_swapLeftRight(c); + /*I don't think this will be an infinate loop*/ + c = constraint_simplify(c); + } + + DPRINTF(( message("constraint_simplify returning %q ", constraint_print(c) ) )); + + return c; } + + + +/* returns true if fileloc for term1 is closer to file for term2 than term3*/ + +bool fileloc_closer (fileloc loc1, fileloc loc2, fileloc loc3) +{ + + if (!fileloc_isDefined (loc1) ) + return FALSE; + + if (!fileloc_isDefined (loc2) ) + return FALSE; + + if (!fileloc_isDefined (loc3) ) + return TRUE; + + + + + if (fileloc_equal (loc2, loc3) ) + return FALSE; + + if (fileloc_equal (loc1, loc2) ) + return TRUE; + + if (fileloc_equal (loc1, loc3) ) + return FALSE; + + if ( fileloc_lessthan (loc1, loc2) ) + { + if (fileloc_lessthan (loc2, loc3) ) + { + llassert (fileloc_lessthan (loc1, loc3) ); + return TRUE; + } + else + { + return FALSE; + } + } + + if ( !fileloc_lessthan (loc1, loc2) ) + { + if (!fileloc_lessthan (loc2, loc3) ) + { + llassert (!fileloc_lessthan (loc1, loc3) ); + return TRUE; + } + else + { + return FALSE; + } + } + + llassert(FALSE); + return FALSE; +} + +