2010-11-03 23:53:14 +01:00
|
|
|
/***** ltl2ba : rewrt.c *****/
|
|
|
|
|
|
|
|
/* Written by Denis Oddoux, LIAFA, France */
|
|
|
|
/* Copyright (c) 2001 Denis Oddoux */
|
|
|
|
/* Modified by Paul Gastin, LSV, France */
|
|
|
|
/* Copyright (c) 2007 Paul Gastin */
|
|
|
|
/* */
|
|
|
|
/* 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. */
|
|
|
|
/* */
|
|
|
|
/* You should have received a copy of the GNU General Public License */
|
|
|
|
/* along with this program; if not, write to the Free Software */
|
|
|
|
/* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA*/
|
|
|
|
/* */
|
|
|
|
/* Based on the translation algorithm by Gastin and Oddoux, */
|
|
|
|
/* presented at the 13th International Conference on Computer Aided */
|
|
|
|
/* Verification, CAV 2001, Paris, France. */
|
|
|
|
/* Proceedings - LNCS 2102, pp. 53-65 */
|
|
|
|
/* */
|
|
|
|
/* Send bug-reports and/or questions to Paul Gastin */
|
|
|
|
/* http://www.lsv.ens-cachan.fr/~gastin */
|
|
|
|
/* */
|
|
|
|
/* Some of the code in this file was taken from the Spin software */
|
|
|
|
/* Written by Gerard J. Holzmann, Bell Laboratories, U.S.A. */
|
|
|
|
|
|
|
|
#include "ltl2ba.h"
|
|
|
|
|
|
|
|
extern int tl_verbose;
|
|
|
|
|
|
|
|
static Node *can = ZN;
|
|
|
|
|
|
|
|
Node *
|
|
|
|
right_linked(Node *n)
|
|
|
|
{
|
|
|
|
if (!n) return n;
|
|
|
|
|
|
|
|
if (n->ntyp == AND || n->ntyp == OR)
|
|
|
|
while (n->lft && n->lft->ntyp == n->ntyp)
|
|
|
|
{ Node *tmp = n->lft;
|
|
|
|
n->lft = tmp->rgt;
|
|
|
|
tmp->rgt = n;
|
|
|
|
n = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
n->lft = right_linked(n->lft);
|
|
|
|
n->rgt = right_linked(n->rgt);
|
|
|
|
|
|
|
|
return n;
|
|
|
|
}
|
|
|
|
|
|
|
|
Node *
|
|
|
|
canonical(Node *n)
|
|
|
|
{ Node *m; /* assumes input is right_linked */
|
|
|
|
|
|
|
|
if (!n) return n;
|
2010-11-29 14:18:10 +01:00
|
|
|
m = in_cache(n);
|
|
|
|
if (m)
|
2010-11-03 23:53:14 +01:00
|
|
|
return m;
|
|
|
|
|
|
|
|
n->rgt = canonical(n->rgt);
|
|
|
|
n->lft = canonical(n->lft);
|
|
|
|
|
|
|
|
return cached(n);
|
|
|
|
}
|
|
|
|
|
|
|
|
Node *
|
|
|
|
push_negation(Node *n)
|
|
|
|
{ Node *m;
|
|
|
|
|
|
|
|
Assert(n->ntyp == NOT, n->ntyp);
|
|
|
|
|
|
|
|
switch (n->lft->ntyp) {
|
|
|
|
case TRUE:
|
|
|
|
releasenode(0, n->lft);
|
|
|
|
n->lft = ZN;
|
|
|
|
n->ntyp = FALSE;
|
|
|
|
break;
|
|
|
|
case FALSE:
|
|
|
|
releasenode(0, n->lft);
|
|
|
|
n->lft = ZN;
|
|
|
|
n->ntyp = TRUE;
|
|
|
|
break;
|
|
|
|
case NOT:
|
|
|
|
m = n->lft->lft;
|
|
|
|
releasenode(0, n->lft);
|
|
|
|
n->lft = ZN;
|
|
|
|
releasenode(0, n);
|
|
|
|
n = m;
|
|
|
|
break;
|
|
|
|
case V_OPER:
|
|
|
|
n->ntyp = U_OPER;
|
|
|
|
goto same;
|
|
|
|
case U_OPER:
|
|
|
|
n->ntyp = V_OPER;
|
|
|
|
goto same;
|
|
|
|
#ifdef NXT
|
|
|
|
case NEXT:
|
|
|
|
n->ntyp = NEXT;
|
|
|
|
n->lft->ntyp = NOT;
|
|
|
|
n->lft = push_negation(n->lft);
|
|
|
|
break;
|
|
|
|
#endif
|
|
|
|
case AND:
|
|
|
|
n->ntyp = OR;
|
|
|
|
goto same;
|
|
|
|
case OR:
|
|
|
|
n->ntyp = AND;
|
|
|
|
|
|
|
|
same: m = n->lft->rgt;
|
|
|
|
n->lft->rgt = ZN;
|
|
|
|
|
|
|
|
n->rgt = Not(m);
|
|
|
|
n->lft->ntyp = NOT;
|
|
|
|
m = n->lft;
|
|
|
|
n->lft = push_negation(m);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
return rewrite(n);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
addcan(int tok, Node *n)
|
|
|
|
{ Node *m, *prev = ZN;
|
|
|
|
Node **ptr;
|
|
|
|
Node *N;
|
|
|
|
Symbol *s, *t; int cmp;
|
|
|
|
|
|
|
|
if (!n) return;
|
|
|
|
|
|
|
|
if (n->ntyp == tok)
|
|
|
|
{ addcan(tok, n->rgt);
|
|
|
|
addcan(tok, n->lft);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
#if 0
|
|
|
|
if ((tok == AND && n->ntyp == TRUE)
|
|
|
|
|| (tok == OR && n->ntyp == FALSE))
|
|
|
|
return;
|
|
|
|
#endif
|
|
|
|
N = dupnode(n);
|
|
|
|
if (!can)
|
|
|
|
{ can = N;
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
s = DoDump(N);
|
|
|
|
if (can->ntyp != tok) /* only one element in list so far */
|
|
|
|
{ ptr = &can;
|
|
|
|
goto insert;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* there are at least 2 elements in list */
|
|
|
|
prev = ZN;
|
|
|
|
for (m = can; m->ntyp == tok && m->rgt; prev = m, m = m->rgt)
|
|
|
|
{ t = DoDump(m->lft);
|
|
|
|
cmp = strcmp(s->name, t->name);
|
|
|
|
if (cmp == 0) /* duplicate */
|
|
|
|
return;
|
|
|
|
if (cmp < 0)
|
|
|
|
{ if (!prev)
|
|
|
|
{ can = tl_nn(tok, N, can);
|
|
|
|
return;
|
|
|
|
} else
|
|
|
|
{ ptr = &(prev->rgt);
|
|
|
|
goto insert;
|
|
|
|
} } }
|
|
|
|
|
|
|
|
/* new entry goes at the end of the list */
|
|
|
|
ptr = &(prev->rgt);
|
|
|
|
insert:
|
|
|
|
t = DoDump(*ptr);
|
|
|
|
cmp = strcmp(s->name, t->name);
|
|
|
|
if (cmp == 0) /* duplicate */
|
|
|
|
return;
|
|
|
|
if (cmp < 0)
|
|
|
|
*ptr = tl_nn(tok, N, *ptr);
|
|
|
|
else
|
|
|
|
*ptr = tl_nn(tok, *ptr, N);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
marknode(int tok, Node *m)
|
|
|
|
{
|
|
|
|
if (m->ntyp != tok)
|
|
|
|
{ releasenode(0, m->rgt);
|
|
|
|
m->rgt = ZN;
|
|
|
|
}
|
|
|
|
m->ntyp = -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
Node *
|
|
|
|
Canonical(Node *n)
|
|
|
|
{ Node *m, *p, *k1, *k2, *prev, *dflt = ZN;
|
|
|
|
int tok;
|
|
|
|
|
|
|
|
if (!n) return n;
|
|
|
|
|
|
|
|
tok = n->ntyp;
|
|
|
|
if (tok != AND && tok != OR)
|
|
|
|
return n;
|
|
|
|
|
|
|
|
can = ZN;
|
|
|
|
addcan(tok, n);
|
|
|
|
#if 1
|
|
|
|
Debug("\nA0: "); Dump(can);
|
|
|
|
Debug("\nA1: "); Dump(n); Debug("\n");
|
|
|
|
#endif
|
|
|
|
releasenode(1, n);
|
|
|
|
|
|
|
|
/* mark redundant nodes */
|
|
|
|
if (tok == AND)
|
|
|
|
{ for (m = can; m; m = (m->ntyp == AND) ? m->rgt : ZN)
|
|
|
|
{ k1 = (m->ntyp == AND) ? m->lft : m;
|
|
|
|
if (k1->ntyp == TRUE)
|
|
|
|
{ marknode(AND, m);
|
|
|
|
dflt = True;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (k1->ntyp == FALSE)
|
|
|
|
{ releasenode(1, can);
|
|
|
|
can = False;
|
|
|
|
goto out;
|
|
|
|
} }
|
|
|
|
for (m = can; m; m = (m->ntyp == AND) ? m->rgt : ZN)
|
|
|
|
for (p = can; p; p = (p->ntyp == AND) ? p->rgt : ZN)
|
|
|
|
{ if (p == m
|
|
|
|
|| p->ntyp == -1
|
|
|
|
|| m->ntyp == -1)
|
|
|
|
continue;
|
|
|
|
k1 = (m->ntyp == AND) ? m->lft : m;
|
|
|
|
k2 = (p->ntyp == AND) ? p->lft : p;
|
|
|
|
|
|
|
|
if (isequal(k1, k2))
|
|
|
|
{ marknode(AND, p);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (anywhere(OR, k1, k2))
|
|
|
|
{ marknode(AND, p);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (k2->ntyp == U_OPER
|
|
|
|
&& anywhere(AND, k2->rgt, can))
|
|
|
|
{ marknode(AND, p);
|
|
|
|
continue;
|
|
|
|
} /* q && (p U q) = q */
|
|
|
|
} }
|
|
|
|
if (tok == OR)
|
|
|
|
{ for (m = can; m; m = (m->ntyp == OR) ? m->rgt : ZN)
|
|
|
|
{ k1 = (m->ntyp == OR) ? m->lft : m;
|
|
|
|
if (k1->ntyp == FALSE)
|
|
|
|
{ marknode(OR, m);
|
|
|
|
dflt = False;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (k1->ntyp == TRUE)
|
|
|
|
{ releasenode(1, can);
|
|
|
|
can = True;
|
|
|
|
goto out;
|
|
|
|
} }
|
|
|
|
for (m = can; m; m = (m->ntyp == OR) ? m->rgt : ZN)
|
|
|
|
for (p = can; p; p = (p->ntyp == OR) ? p->rgt : ZN)
|
|
|
|
{ if (p == m
|
|
|
|
|| p->ntyp == -1
|
|
|
|
|| m->ntyp == -1)
|
|
|
|
continue;
|
|
|
|
k1 = (m->ntyp == OR) ? m->lft : m;
|
|
|
|
k2 = (p->ntyp == OR) ? p->lft : p;
|
|
|
|
|
|
|
|
if (isequal(k1, k2))
|
|
|
|
{ marknode(OR, p);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (anywhere(AND, k1, k2))
|
|
|
|
{ marknode(OR, p);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (k2->ntyp == V_OPER
|
|
|
|
&& k2->lft->ntyp == FALSE
|
|
|
|
&& anywhere(AND, k2->rgt, can))
|
|
|
|
{ marknode(OR, p);
|
|
|
|
continue;
|
|
|
|
} /* p || (F V p) = p */
|
|
|
|
} }
|
|
|
|
for (m = can, prev = ZN; m; ) /* remove marked nodes */
|
|
|
|
{ if (m->ntyp == -1)
|
|
|
|
{ k2 = m->rgt;
|
|
|
|
releasenode(0, m);
|
|
|
|
if (!prev)
|
|
|
|
{ m = can = can->rgt;
|
|
|
|
} else
|
|
|
|
{ m = prev->rgt = k2;
|
|
|
|
/* if deleted the last node in a chain */
|
|
|
|
if (!prev->rgt && prev->lft
|
|
|
|
&& (prev->ntyp == AND || prev->ntyp == OR))
|
|
|
|
{ k1 = prev->lft;
|
|
|
|
prev->ntyp = prev->lft->ntyp;
|
|
|
|
prev->sym = prev->lft->sym;
|
|
|
|
prev->rgt = prev->lft->rgt;
|
|
|
|
prev->lft = prev->lft->lft;
|
|
|
|
releasenode(0, k1);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
prev = m;
|
|
|
|
m = m->rgt;
|
|
|
|
}
|
|
|
|
out:
|
|
|
|
#if 1
|
|
|
|
Debug("A2: "); Dump(can); Debug("\n");
|
|
|
|
#endif
|
|
|
|
if (!can)
|
|
|
|
{ if (!dflt)
|
|
|
|
fatal("cannot happen, Canonical", (char *) 0);
|
|
|
|
return dflt;
|
|
|
|
}
|
|
|
|
|
|
|
|
return can;
|
|
|
|
}
|