ack/util/grind/scope.cc
1990-10-17 17:00:03 +00:00

148 lines
2.8 KiB
C++

/* Scope mechanism */
/* $Header$ */
#include <assert.h>
#include <alloc.h>
#include <out.h>
#include "position.h"
#include "file.h"
#include "idf.h"
#include "type.h"
#include "symbol.h"
#include "scope.h"
#include "avl.h"
p_scope PervasiveScope, CurrentScope, FileScope;
/* STATICALLOCDEF "scope" 10 */
static AVL_tree ScopeTree;
static int
cmp_starts(s1, s2)
char *s1, *s2;
{
register p_scope c1 = (p_scope)s1, c2 = (p_scope)s2;
return c1->sc_start < c2->sc_start
? -1
: c1->sc_start == c2->sc_start
? 0
: 1;
}
/*ARGSUSED*/
open_scope(name, has_activation)
p_symbol name;
int has_activation;
{
register p_scope sc = new_scope();
sc->sc_has_activation_record = has_activation;
sc->sc_static_encl = CurrentScope;
sc->sc_definedby = name;
sc->sc_proclevel = CurrentScope->sc_proclevel;
/* sc_proclevel possibly reset by caller */
CurrentScope = sc;
}
init_scope()
{
register p_scope sc = new_scope();
PervasiveScope = sc;
CurrentScope = sc;
open_scope((p_symbol) 0, 0); /* this one will be closed at the
first N_SO
*/
ScopeTree = create_avl_tree(cmp_starts);
}
close_scope()
{
register p_scope sc = CurrentScope;
assert(sc != 0);
CurrentScope = sc->sc_static_encl;
}
add_scope_addr(scope)
p_scope scope;
{
add_to_avl_tree(ScopeTree, (char *)scope);
}
/* extern p_scope get_scope_from_addr(t_addr a);
Returns the scope of the code at address 'a', or 0 if it could not be found.
*/
p_scope
get_scope_from_addr(a)
t_addr a;
{
t_scope sc;
sc.sc_start = a;
return (p_scope) find_ngt(ScopeTree, (char *) &sc);
}
/* extern p_scope get_next_scope_from_addr(t_addr a);
Returns the scope following the one of the code at address 'a',
and that has an activation record,
or 0 if it could not be found.
*/
p_scope
get_next_scope_from_addr(a)
t_addr a;
{
t_scope sc;
sc.sc_start = a;
for (;;) {
p_scope psc = (p_scope) find_nlt(ScopeTree, (char *) &sc);
if (! psc || psc->sc_has_activation_record) return psc;
sc.sc_start = psc->sc_start+1;
}
/*NOTREACHED*/
}
/* extern int has_static_link(p_scope sc);
Returns 1 if the procedure of this scope takes a static link.
*/
int
has_static_link(sc)
register p_scope sc;
{
return sc->sc_proclevel > 1;
}
/* extern p_scope base_scope(p_scope sc);
Returns the closest enclosing scope of 'sc' that has an activation record.
*/
p_scope
base_scope(sc)
register p_scope sc;
{
while (sc && ! sc->sc_has_activation_record) {
sc = sc->sc_static_encl;
}
return sc;
}
/* extern int scope_encloses(p_scope scope, from_scope);
Returns 1 if scope encloses from from_scope, 0 otherwise.
*/
int
scope_encloses(scope, from_scope)
p_scope scope, from_scope;
{
register p_scope sc = from_scope;
while (sc) {
if (sc == scope) return 1;
sc = sc->sc_static_encl;
}
return 0;
}