/* ** Splint - annotation-assisted static program checker ** Copyright (C) 1994-2003 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 "splintMacros.nf" # include "basic.h" # include "cgrammar.h" # include "cgrammar_tokens.h" # include "exprChecks.h" # include "exprNodeSList.h" /*@access constraint, exprNode @*/ /*!!! NO! Don't do this so recklessly - design your code more carefully so you don't need to! */ static constraint inequalitySubstitute (/*@returned@*/ constraint p_c, constraintList p_p); static bool rangeCheck (arithType p_ar1, /*@observer@*/ constraintExpr p_expr1, arithType p_ar2, /*@observer@*/ constraintExpr p_expr2); static constraint inequalitySubstituteUnsound (/*@returned@*/ constraint p_c, constraintList p_p); 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); /*@only@*/ constraintList constraintList_mergeEnsuresFreeFirst (constraintList list1, constraintList list2) { constraintList ret; ret = constraintList_mergeEnsures (list1, list2); constraintList_free(list1); return ret; } /*@only@*/ constraintList constraintList_mergeEnsures (constraintList list1, constraintList list2) { constraintList ret; constraintList temp; llassert(constraintList_isDefined(list1) ); llassert(constraintList_isDefined(list2) ); DPRINTF(( message ("constraintList_mergeEnsures: list1 %s list2 %s", constraintList_unparse(list1), constraintList_unparse(list2) ))); ret = constraintList_fixConflicts (list1, list2); ret = reflectChangesEnsuresFree1 (ret, list2); temp = constraintList_subsumeEnsures (ret, list2); constraintList_free(ret); ret = temp; temp = constraintList_subsumeEnsures (list2, ret); temp = constraintList_addList (temp, ret); constraintList_free(ret); DPRINTF(( message ("constraintList_mergeEnsures: returning %s ", constraintList_unparse(temp) ) )); return temp; } /*@only@*/ constraintList constraintList_mergeRequiresFreeFirst (/*@only@*/ constraintList list1, constraintList list2) { constraintList ret; ret = constraintList_mergeRequires(list1, list2); constraintList_free(list1); return ret; } /*@only@*/ constraintList constraintList_mergeRequires (constraintList list1, constraintList list2) { constraintList ret; constraintList temp; DPRINTF((message ("constraintList_mergeRequires: merging %s and %s ", constraintList_unparse (list1), constraintList_unparse(list2) ) ) ); if (context_getFlag (FLG_REDUNDANTCONSTRAINTS) ) { 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_unparse(temp) ) ) ); /*get constraints in list2 not satified by temp*/ ret = constraintList_reflectChanges(list2, temp); DPRINTF((message ("constraintList_mergeRequires: ret = %s", constraintList_unparse(ret) ) ) ); ret = constraintList_addListFree (ret, temp); DPRINTF((message ("constraintList_mergeRequires: returning %s", constraintList_unparse(ret) ) ) ); return ret; } /* old name mergeResolve renamed for czech naming convention */ void exprNode_mergeResolve (exprNode parent, exprNode child1, exprNode child2) { 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_isUndefined(parent) ) { llassert (exprNode_isDefined(parent) ); return; } 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_unparse( child2->requiresConstraints), constraintList_unparse (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_unparse (child1->requiresConstraints), constraintList_unparse (child1->ensuresConstraints), constraintList_unparse (child2->requiresConstraints), constraintList_unparse (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 temp = constraintList_reflectChanges(child2->requiresConstraints, child1->ensuresConstraints); temp2 = constraintList_mergeRequires (parent->requiresConstraints, temp); constraintList_free(parent->requiresConstraints); constraintList_free(temp); parent->requiresConstraints = temp2; DPRINTF((message ("Parent requires constraints are %s ", constraintList_unparse (parent->requiresConstraints) ) ) ); constraintList_free(parent->ensuresConstraints); parent->ensuresConstraints = constraintList_mergeEnsures(child1->ensuresConstraints, child2->ensuresConstraints); DPRINTF((message ("Parent constraints are %s and %s ", constraintList_unparse (parent->requiresConstraints), constraintList_unparse (parent->ensuresConstraints) ) ) ); } /*@only@*/ constraintList constraintList_subsumeEnsures (constraintList list1, constraintList list2) { constraintList ret; ret = constraintList_makeNew(); constraintList_elements (list1, el) { DPRINTF ((message ("Examining %s", constraint_unparse (el) ) ) ); if (!constraintList_resolve (el, list2) ) { constraint temp; temp = constraint_copy(el); ret = constraintList_add (ret, temp); } else { DPRINTF ((message ("Subsuming %s", constraint_unparse (el) ) ) ); } } end_constraintList_elements; 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); 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; constraint temp2; llassert (! context_getFlag (FLG_ORCONSTRAINT) ); ret = constraintList_makeNew(); DPRINTF((message ("reflectChanges: lists %s and %s", constraintList_unparse(pre2), constraintList_unparse(post1) ))); constraintList_elements (pre2, el) { if (!constraintList_resolve (el, post1) ) { 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_unparse(ret) ) ) ); return ret; } /* tries to resolve constraints in list pre2 using post1 */ /*@only@*/ constraintList constraintList_reflectChanges(/*@observer@*/ constraintList pre2, /*@observer@*/ constraintList post1) { constraintList temp; if ( context_getFlag (FLG_ORCONSTRAINT) ) temp = constraintList_reflectChangesOr (pre2, post1); else temp = reflectChangesNoOr(pre2, post1); return temp; } static constraint constraint_addOr (/*@returned@*/ constraint orig, /*@observer@*/ constraint orConstr) { constraint c; llassertfatal(constraint_isDefined(orig) ); c = orig; DPRINTF((message("constraint_addor: oring %s onto %s", constraint_unparseOr(orConstr), constraint_unparseOr(orig) ) )); while (c->or != NULL) { c = c->or; } c->or = constraint_copy(orConstr); DPRINTF((message("constraint_addor: returning %s",constraint_unparseOr(orig) ) )); return orig; } static bool resolveOr ( /*@temp@*/ constraint c, /*@observer@*/ /*@temp@*/ constraintList list) { constraint temp; int numberOr; numberOr = 0; llassertfatal(constraint_isDefined(c) ); DPRINTF(( message("resolveOr: constraint %s and list %s", constraint_unparseOr(c), constraintList_unparse(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_isDefined (c ) ); DPRINTF((message("doResolve:: call on constraint c = : %q and constraintList %q", constraint_unparseOr(c), constraintList_unparse(post1) ) )); if (!resolveOr (c, post1) ) { temp = constraint_substitute (c, post1); DPRINTF((message("doResolve:: after substitute temp is %q", constraint_unparseOr(temp) ) )); if (!resolveOr (temp, post1) ) { /* 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 (!resolveOr (temp2, post1) ) { constraint temp3; temp3 = constraint_copy(temp2); temp3 = inequalitySubstituteStrong (temp3, post1); if (!resolveOr (temp3, post1) ) { temp2 = inequalitySubstituteUnsound (temp2, post1); if (!resolveOr (temp2, post1) ) { if (!constraint_same (temp, temp2) ) { /* drl added 8/28/2002*/ /*make sure that the information from a post condition like i = i + 1 is transfered */ constraint tempSub; tempSub = constraint_substitute (temp2, post1); DPRINTF(( message("doResolve: adding %s ", constraint_unparseOr(tempSub) ) )); DPRINTF(( message("doResolve: not adding %s ", constraint_unparseOr(temp2) ) )); temp = constraint_addOr (temp, tempSub); constraint_free(tempSub); } if (!constraint_same (temp, temp3) && !constraint_same (temp3, temp2) ) { /* drl added 8/28/2002*/ /*make sure that the information from a post condition like i = i + 1 is transfered */ constraint tempSub; tempSub = constraint_substitute (temp3, post1); DPRINTF(( message("doResolve: adding %s ", constraint_unparseOr(tempSub) ) )); DPRINTF(( message("doResolve: not adding %s ", constraint_unparseOr(temp3) ) )); temp = constraint_addOr (temp, tempSub); constraint_free(tempSub); } *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); } constraint_free(c); *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_unparseOr(c), constraintList_unparse(post1) ) )); *resolved = FALSE; llassertfatal(constraint_isDefined(c) ); ret = constraint_copy(c); llassert(constraint_isDefined(ret) ); 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); 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); } DPRINTF(( message("doResolveOr: returning ret = %s", constraint_unparseOr(ret) ) )); 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_unparse(pre2), constraintList_unparse(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_unparse(ret) ) ) ); return ret; } static /*@only@*/ constraintList reflectChangesEnsures (/*@observer@*/ constraintList pre2, constraintList post1) { constraintList ret; constraint temp; ret = constraintList_makeNew(); constraintList_elements (pre2, el) { if (!constraintList_resolve (el, post1) ) { 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_unparse(el) ) ) ); } } end_constraintList_elements; return ret; } static /*@only@*/ constraintList reflectChangesEnsuresFree1 (/*@only@*/ constraintList pre2, constraintList post1) { constraintList ret; ret = reflectChangesEnsures (pre2, post1); constraintList_free(pre2); return ret; } static bool constraint_conflict (constraint c1, constraint c2) { if (!constraint_isDefined(c1) || !constraint_isDefined(c2)) { return FALSE; } if (constraintExpr_similar (c1->lexpr, c2->lexpr)) { if (c1->ar == EQ) if (c1->ar == c2->ar) { DPRINTF (("%s conflicts with %s", constraint_unparse (c1), constraint_unparse (c2))); return TRUE; } } /* This is a slight kludge to prevent circular constraints like strlen(str) == maxRead(s) + strlen(str); */ /*this code is functional but it may be worth cleaning up at some point. */ 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_unparse (c1), constraint_unparse(c2) ) ) ); return TRUE; } } } if (constraint_tooDeep(c1) || constraint_tooDeep(c2) ) { DPRINTF ((message ("%s conflicts with %s (constraint is too deep", constraint_unparse (c1), constraint_unparse(c2) ) ) ); return TRUE; } DPRINTF ((message ("%s doesn't conflict with %s ", constraint_unparse (c1), constraint_unparse(c2) ) ) ); return FALSE; } static void constraint_fixConflict (/*@temp@*/ constraint good, /*@temp@*/ /*@observer@*/ constraint conflicting) /*@modifies good@*/ { llassertfatal(constraint_isDefined(conflicting) ); if (conflicting->ar == EQ) { llassertfatal (constraint_isDefined(good)); DPRINTF (("Replacing here!")); 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 satisfies cosntriant pre */ static bool constraintResolve_satisfies (constraint pre, constraint post) { if (!constraint_isDefined (pre)) { return TRUE; } if (!constraint_isDefined(post)) { return FALSE; } 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) { DPRINTF (("[resolve] Trying to resolve constraint: %s using %s", constraint_unparse (c), constraintList_unparse (p))); constraintList_elements (p, el) { if (constraintResolve_satisfies (c, el)) { DPRINTF (("constraintList_resolve: %s satifies %s", constraint_unparse (el), constraint_unparse (c))); return TRUE; } DPRINTF (("constraintList_resolve: %s does not satify %s\n ", constraint_unparse (el), constraint_unparse (c))); } end_constraintList_elements; DPRINTF (("No constraints satify: %s", constraint_unparse (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; llassertfatal(constraintExpr_isDefined(buf1) && constraintExpr_isDefined(expr2) ); /*@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); llassert (exprNode_isDefined(e)); if (! (exprNode_isDefined(e))) return FALSE; if (e->kind != XPR_SIZEOF) return FALSE; t = exprData_getSingle (e->edata); s1 = exprNode_getSref (t); s2 = constraintTerm_getsRef(constraintExprData_termGetTerm(buf1->data) ); /*drl this may be the wronge thing to test for but this seems to work correctly*/ if (sRef_similarRelaxed(s1, s2) || sRef_sameName (s1, s2) ) { /* origly checked that ctype_isFixedArray(sRef_getType(s2)) but removed that test */ return TRUE; } return FALSE; } /* look for the special case of maxSet(buf) >= sizeof(buf) - 1 */ /*drl eventually it would be good to check that buf is of type char.*/ static bool sizeOfMaxSet( /*@observer@*/ /*@temp@*/ constraint c) { constraintExpr l, r, buf1, buf2, con; DPRINTF(( message("sizeOfMaxSet: checking %s ", constraint_unparse(c) ) )); llassertfatal (constraint_isDefined(c) ); l = c->lexpr; r = c->expr; if (!((c->ar == EQ) || (c->ar == GTE) || (c->ar == LTE) ) ) return FALSE; llassert (constraintExpr_isDefined(l) ); llassert (constraintExpr_isDefined(r) ); /*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; llassert (constraint_isDefined(c) ); l = c->lexpr; r = c->expr; DPRINTF(( message("constraint_IsAlwaysTrue:examining %s", constraint_unparse(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_unparse(c) ) )); return FALSE; } BADEXIT; } static bool rangeCheck (arithType ar1, /*@observer@*/ constraintExpr expr1, arithType ar2, /*@observer@*/ constraintExpr expr2) { DPRINTF (("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) { llassertfatal (constraint_isDefined(c)); DPRINTF (("Starting replace lexpr [%p]: %s < %s ==> %s > in %s", c, constraintExpr_unparse (c->lexpr), constraintExpr_unparse (old), constraintExpr_unparse (newExpr), constraint_unparse (c))); c->lexpr = constraintExpr_searchandreplace (c->lexpr, old, newExpr); DPRINTF (("Finished replace lexpr [%p]: %s", c, constraintExpr_unparse (c->lexpr))); c->expr = constraintExpr_searchandreplace (c->expr, old, newExpr); return c; } bool constraint_search (constraint c, constraintExpr old) /*@*/ { bool ret; ret = FALSE; llassert (constraint_isDefined (c)); 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_unparse(substitute), constraint_unparse(old)) )); llassert(constraint_isDefined(substitute)); llassert(constraint_isDefined(old)); loc1 = constraint_getFileloc (old); loc2 = constraintExpr_loc (substitute->lexpr); loc3 = constraintExpr_loc (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_unparse(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) { llassert(constraint_isDefined(c) ); if (c->ar != GTE) return c; constraintList_elements (p, el) { llassert(constraint_isDefined(el) ); if ((el->ar == LT ) ) { constraintExpr temp2; if (constraintExpr_same (el->expr, c->expr) ) { DPRINTF((message ("inequalitySubstitute Replacing %q in %q with %q", constraintExpr_print (c->expr), constraint_unparse (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_unparse(c) ) )); llassert(constraint_isDefined(c) ); if (! (constraint_isDefined(c) ) ) { return c; } if (c->ar != GTE) return c; DPRINTF (( message ("inequalitySubstituteStrong examining substituting for %q with %q", constraint_unparse(c), constraintList_unparse(p) ) )); constraintList_elements (p, el) { DPRINTF (( message ("inequalitySubstituteStrong examining substituting %s on %s", constraint_unparse(el), constraint_unparse(c) ) )); llassert(constraint_isDefined(el) ); if ((el->ar == LT ) || (el->ar == LTE ) ) { constraintExpr temp2; if (constraintExpr_same (el->lexpr, c->expr) ) { DPRINTF((message ("inequalitySubstitute Replacing %s in %s with %s", constraintExpr_print (c->expr), constraint_unparse (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 " ) )); llassert(constraint_isDefined(c) ); if (c->ar != GTE) return c; constraintList_elements (p, el) { llassert(constraint_isDefined(el) ); DPRINTF (( message ("inequalitySubstituteUnsound examining substituting %s on %s", constraint_unparse(el), constraint_unparse(c) ) )); if (( el->ar == LTE) || (el->ar == LT) ) { 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 = constraint_copy (c); constraintList_elements (p, el) { if (constraint_isDefined (el)) { if ( el->ar == EQ) if (!constraint_conflict (ret, el)) { constraint temp = constraint_copy(el); temp = constraint_adjust(temp, ret); llassert(constraint_isDefined(temp) ); DPRINTF (("constraint_substitute :: Substituting in %s using %s", constraint_unparse (ret), constraint_unparse (temp))); ret = constraint_searchandreplace (ret, temp->lexpr, temp->expr); DPRINTF (("constraint_substitute :: The new constraint is %s", constraint_unparse (ret)));; constraint_free(temp); } } } end_constraintList_elements; ret = constraint_simplify (ret); DPRINTF(( message (" constraint_substitute :: The final new constraint is %s", constraint_unparse (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) { llassert(constraint_isDefined(c) ); DPRINTF((message ("Solving %s\n", constraint_unparse(c) ) ) ); c->expr = constraintExpr_solveBinaryExpr (c->lexpr, c->expr); DPRINTF((message ("Solved and got %s\n", constraint_unparse(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; llassert(constraint_isDefined(c) ); 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) { llassert(constraint_isDefined(c) ); DPRINTF(( message("constraint_simplify on %q ", constraint_unparse(c) ) )); if (constraint_tooDeep(c)) { DPRINTF(( message("constraint_simplify: constraint to complex aborting %q ", constraint_unparse(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_unparse(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; }