scyther/src/binding.c
ccremers 25244c5b23 - Fixed bug in new tuple expansion code (again, caused by the intricate
"realX" versus "isX" distinction.)
- Added structures for rho, sigma, constants, but did not activate them
  yet.
2006-03-15 08:51:08 +00:00

570 lines
11 KiB
C

/**
* Handle bindings for Arache engine.
*/
#include "list.h"
#include "role.h"
#include "label.h"
#include "system.h"
#include "binding.h"
#include "warshall.h"
#include "debug.h"
#include "term.h"
#include "termmap.h"
#include "arachne.h"
#include "switches.h"
#include "depend.h"
#include <malloc.h>
static System sys; //!< local storage of system pointer
extern Protocol INTRUDER; //!< The intruder protocol
extern Role I_M; //!< special role; precedes all other events always
/*
*
* Assist stuff
*
*/
//! Create mem for binding
Binding
binding_create (Term term, int run_to, int ev_to)
{
Binding b;
b = malloc (sizeof (struct binding));
b->done = false;
b->blocked = false;
b->run_from = -1;
b->ev_from = -1;
b->run_to = run_to;
b->ev_to = ev_to;
b->term = term;
b->level = 0;
return b;
}
//! Remove mem for binding
void
binding_destroy (Binding b)
{
if (b->done)
{
goal_unbind (b);
}
free (b);
}
/*
*
* Main
*
*/
//! Init module
void
bindingInit (const System mysys)
{
sys = mysys;
sys->bindings = NULL;
dependInit (sys);
}
//! Close up
void
bindingDone ()
{
int delete (Binding b)
{
binding_destroy (b);
return true;
}
list_iterate (sys->bindings, delete);
list_destroy (sys->bindings);
dependDone (sys);
}
/**
*
* Externally available functions
*
*/
//! Print a binding (given a binding list pointer)
int
binding_print (const Binding b)
{
if (b->done)
eprintf ("Binding (%i,%i) --( ", b->run_from, b->ev_from);
else
eprintf ("Unbound --( ");
termPrint (b->term);
eprintf (" )->> (%i,%i)", b->run_to, b->ev_to);
if (b->blocked)
eprintf ("[blocked]");
return true;
}
//! Bind a goal (true if success, false if it must be pruned)
int
goal_bind (const Binding b, const int run, const int ev)
{
if (b->blocked)
{
error ("Trying to bind a blocked goal.");
}
if (!b->done)
{
#ifdef DEBUG
if (run >= sys->maxruns || sys->runs[run].step <= ev)
{
globalError++;
eprintf ("For term: ");
termPrint (b->term);
eprintf (" needed for r%ii%i.\n", b->run_to, b->ev_to);
eprintf ("Current limits: %i runs, %i events for this run.\n",
sys->maxruns, sys->runs[run].step);
globalError--;
error
("trying to bind to something not yet in the semistate: r%ii%i.",
run, ev);
}
#endif
b->run_from = run;
b->ev_from = ev;
if (dependPushEvent (run, ev, b->run_to, b->ev_to))
{
b->done = true;
if (switches.output == PROOF)
{
indentPrint ();
binding_print (b);
eprintf ("\n");
}
return true;
}
}
else
{
globalError++;
binding_print (b);
error ("Trying to bind a bound goal again.");
}
return false;
}
//! Unbind a goal
void
goal_unbind (const Binding b)
{
if (b->done)
{
dependPopEvent ();
b->done = false;
}
else
{
error ("Trying to unbind an unbound goal again.");
}
}
//! Bind a goal as a dummy (block)
/**
* Especially made for tuple expansion
*/
int
binding_block (Binding b)
{
if (!b->blocked)
{
b->blocked = true;
return true;
}
else
{
error ("Trying to block a goal again.");
}
}
//! Unblock a binding
int
binding_unblock (Binding b)
{
if (b->blocked)
{
b->blocked = false;
return true;
}
else
{
error ("Trying to unblock a non-blocked goal.");
}
}
//! Add a goal
/**
* The int parameter 'level' is just to store additional info. Here, it stores priorities for a goal.
* Higher level goals will be selected first. Typically, a normal goal is level 0, a key is 1.
*
* Returns the number of added goals (sometimes unfolding tuples)
*/
int
goal_add (Term term, const int run, const int ev, const int level)
{
term = deVar (term);
#ifdef DEBUG
if (term == NULL)
{
globalError++;
roledefPrint (eventRoledef (sys, run, ev));
eprintf ("\n");
globalError--;
error ("Trying to add an emtpy goal term to r%ii%i, with level %i.",
run, ev, level);
}
if (run >= sys->maxruns)
error ("Trying to add a goal for a run that does not exist.");
if (ev >= sys->runs[run].step)
error
("Trying to add a goal for an event that is not in the semistate yet.");
#endif
if (realTermTuple (term))
{
return goal_add (TermOp1 (term), run, ev, level) +
goal_add (TermOp2 (term), run, ev, level);
}
else
{
// Determine whether we already had it
int createnew;
int testSame (void *data)
{
Binding b;
b = (Binding) data;
if (isTermEqual (b->term, term))
{
// binding of same term
if (run == b->run_to && ev == b->ev_to)
{
// identical binding
createnew = false;
}
}
return true;
}
createnew = true;
list_iterate (sys->bindings, testSame);
if (createnew)
{
// Add a new binding
Binding b;
b = binding_create (term, run, ev);
b->level = level;
sys->bindings = list_insert (sys->bindings, b);
#ifdef DEBUG
if (DEBUGL (3))
{
eprintf ("Adding new binding for ");
termPrint (term);
eprintf (" to run %i, ev %i.\n", run, ev);
}
#endif
return 1;
}
}
return 0;
}
//! Remove a goal
void
goal_remove_last (int n)
{
while (n > 0)
{
if (sys->bindings != NULL)
{
Binding b;
b = (Binding) sys->bindings->data;
binding_destroy (b);
sys->bindings = list_delete (sys->bindings);
n--;
}
else
{
error
("goal_remove_last error: trying to remove %i too many bindings.",
n);
}
}
}
//! Determine whether some label set is ordered w.r.t. send/read order.
/**
* Assumes all these labels exist in the system, within length etc, and that the run mappings are valid.
*/
int
labels_ordered (Termmap runs, Termlist labels)
{
while (labels != NULL)
{
// Given this label, and the mapping of runs, we want to know if the order is okay. Thus, we need to know sendrole and readrole
Labelinfo linfo;
int send_run, send_ev, read_run, read_ev;
int get_index (const int run)
{
Roledef rd;
int i;
i = 0;
rd = sys->runs[run].start;
while (rd != NULL && !isTermEqual (rd->label, labels->term))
{
rd = rd->next;
i++;
}
#ifdef DEBUG
if (rd == NULL)
error
("Could not locate send or read for label, after niagree holds, to test for order.");
#endif
return i;
}
linfo = label_find (sys->labellist, labels->term);
send_run = termmapGet (runs, linfo->sendrole);
read_run = termmapGet (runs, linfo->readrole);
send_ev = get_index (send_run);
read_ev = get_index (read_run);
if (!isDependEvent (send_run, send_ev, read_run, read_ev))
{
// Not ordered; false
return false;
}
// Proceed
labels = labels->next;
}
return true;
}
//! Check whether the binding denotes a sensible thing such that we can use run_from and ev_from
int
valid_binding (Binding b)
{
if (b->done && (!b->blocked))
return true;
else
return false;
}
//! Iterate over all bindings
/**
* Iterator should return true to proceed
*/
int
iterate_bindings (int (*func) (Binding b))
{
List bl;
for (bl = sys->bindings; bl != NULL; bl = bl->next)
{
Binding b;
b = (Binding) bl->data;
if (!func (b))
{
return false;
}
}
return true;
}
//! Iterate over preceding bindings (this does not include stuff bound to the same destination)
/**
* Iterator should return true to proceed
*/
int
iterate_preceding_bindings (const int run, const int ev,
int (*func) (Binding b))
{
int precs (Binding b)
{
if (isDependEvent (b->run_to, b->ev_to, run, ev))
{
return func (b);
}
return true;
}
return iterate_bindings (precs);
}
//! Check for unique origination
/*
* Contrary to a previous version, we simply check for unique origination.
* This immediately takes care of any 'occurs before' things. Complexity is N
* log N.
*
* Each term should originate only at one point (thus in one binding)
*
*@returns True, if it's okay. If false, it needs to be pruned.
*/
int
unique_origination ()
{
List bl;
bl = sys->bindings;
while (bl != NULL)
{
Binding b;
b = (Binding) bl->data;
// Check for a valid binding; it has to be 'done' and sensibly bound (not as in tuple expanded stuff)
if (valid_binding (b))
{
Termlist terms;
terms = tuple_to_termlist (b->term);
if (terms != NULL)
{
/* Apparently this is a good term.
* Now we check whether it occurs in any previous bindings as well.
*/
List bl2;
bl2 = sys->bindings;
while (bl2 != bl)
{
Binding b2;
b2 = (Binding) bl2->data;
if (valid_binding (b2))
{
Termlist terms2, sharedterms;
terms2 = tuple_to_termlist (b2->term);
sharedterms = termlistConjunct (terms, terms2);
// Compare terms
if (sharedterms != NULL)
{
// Apparently, this binding shares a term.
// Equal terms should originate at the same point
if (b->run_from != b2->run_from ||
b->ev_from != b2->ev_from)
{
// Not equal: thus no unique origination.
return false;
}
}
termlistDelete (terms2);
termlistDelete (sharedterms);
}
bl2 = bl2->next;
}
}
termlistDelete (terms);
}
bl = bl->next;
}
return true;
}
//! Prune invalid state w.r.t. <=C minimal requirement
/**
* Intuition says this can be done a lot more efficient. Luckily this is the prototype.
*
*@returns True, if it's okay. If false, it needs to be pruned.
*/
int
bindings_c_minimal ()
{
if (!unique_origination ())
{
return false;
}
{
List bl;
// For all goals
bl = sys->bindings;
while (bl != NULL)
{
Binding b;
b = (Binding) bl->data;
// Check for a valid binding; it has to be 'done' and sensibly bound (not as in tuple expanded stuff)
if (valid_binding (b))
{
int run;
// Find all preceding events
for (run = 0; run < sys->maxruns; run++)
{
int ev;
//!@todo hardcoded reference to step, should be length
for (ev = 0; ev < sys->runs[run].step; ev++)
{
if (isDependEvent (run, ev, b->run_from, b->ev_from))
{
// this node is *before* the from node
Roledef rd;
rd = roledef_shift (sys->runs[run].start, ev);
if (termInTerm (rd->message, b->term))
{
// This term already occurs as interm in a previous node!
#ifdef DEBUG
if (DEBUGL (4))
{
// Report this
indentPrint ();
eprintf ("Binding for ");
termPrint (b->term);
eprintf
(" at r%i i%i is not c-minimal because it occurred before at r%i i%i in ",
b->run_from, b->ev_from, run, ev);
termPrint (rd->message);
eprintf ("\n");
}
#endif
return false;
}
}
else
{
// If this event is not before the target, then the
// next in the run certainly is not either (because
// that would imply that this one is before it)
// Thus, we effectively exit the loop.
break;
}
}
}
}
bl = bl->next;
}
}
return true;
}