static int goto_passable(stmt *s)
{
struct label *lbl;
int passable;
if(s->expr){
/* could jump anywhere - assume it's not passable */
return 0;
}
lbl = s->bits.lbl.label;
if(!lbl)
return 1; /* safety */
if(!lbl->next_stmt)
return 1;
if(lbl->doing_passable_check){
/* infinite loop */
return 0;
}
/* this isn't perfect as it doesn't detect things like:
* x:
* printf("hi\n");
* goto x;
*
* but better to pessimise and warn/insert-main-return-0
* than to miss.
*/
lbl->doing_passable_check = 1;
passable = fold_passable(lbl->next_stmt);
lbl->doing_passable_check = 0;
return passable;
}
int label_passable(stmt *s)
{
return fold_passable(s->lhs);
}
static int if_passable(stmt *s)
{
return fold_passable(s->lhs) || (s->rhs ? fold_passable(s->rhs) : 0);
}
static int if_passable(stmt *s)
{
return (s->rhs ? fold_passable(s->rhs) : 1) || fold_passable(s->lhs);
}
