[Bug fortran/49648] ICE(segfault) with MATHMUL and function-result actual argument

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49648

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-07-05 19:00:51 UTC ---
Draft patch, which seems to fix some ref->u.ar->as issues for "p" - but not the
one, I am looking for. At least the added assert now triggers.

 * * *

Debugging shows that when resolving MAXMUL, one calls resolve_actual_arglist
for SIZE's p. At that point "p's e->ref->u.ar.as == NULL, which is fixed. One
then resolves MAXMUL in resolve_actual_arglist for getPhaseMatrix; if one now
looks at getPhaseMatrix's e->symtree->n.sym->as->upper[0], one finds:

(gdb) p arg->expr->symtree->n.sym->as->upper[0]->value.function.isym->id
$11 = GFC_ISYM_SIZE
(gdb) p
arg->expr->symtree->n.sym->as->upper[0]->value.function.actual->expr->symtree->n.sym->name
$12 = 0x2aaaaab42fa0 "p"
(gdb) p
arg->expr->symtree->n.sym->as->upper[0]->value.function.actual->expr->ref->u.ar.as.
A syntax error in expression, near `'.
(gdb) p
arg->expr->symtree->n.sym->as->upper[0]->value.function.actual->expr->ref->u.ar.as
$13 = (gfc_array_spec *) 0x159f830

Which also looks fine.



Seemingly, the problem is really the result variable - which seems to be
carried through:

(gdb) p arg->expr->symtree->n.sym->result->name
$17 = 0x2aaaaab42fb8 "pm"

And as both "as" are different:

(gdb) p arg->expr->symtree->n.sym->result->as
$18 = (gfc_array_spec *) 0x159ef70
(gdb) p arg->expr->symtree->n.sym->as
$19 = (gfc_array_spec *) 0x159cd40

it is not surprising that one get's at the end:

(gdb) p
arg->expr->symtree->n.sym->result->as->upper[0]->value.function.actual->expr->ref->u.ar.as
$14 = (gfc_array_spec *) 0x0

If one removes the RESULT(), it works - even without the patch.


--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -7506,6 +7521,7 @@ gfc_walk_variable_expr (gfc_ss * ss, gfc_expr * expr)

       ar = &ref->u.ar;

+      gcc_assert (ar->as);
       if (ar->as->rank == 0 && ref->next != NULL)
        {
          /* Scalar coarray.  */
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -82,6 +82,11 @@ static bitmap_obstack labels_obstack;
 /* True when simplifying a EXPR_VARIABLE argument to an inquiry function.  */
 static bool inquiry_argument = false;

+
+/* Prototypes of static functions.  */
+static gfc_try resolve_ref (gfc_expr *);
+
+
 int
 gfc_is_formal_arg (void)
 {
@@ -1577,6 +1582,9 @@ resolve_actual_arglist (gfc_actual_arglist *arg,
procedure_type ptype,
            && count_specific_procs (e) != 1)
        return FAILURE;

+      if (e->ref && e->symtree->n.sym->attr.use_assoc)
+       resolve_ref (e);
+
       if (e->ts.type != BT_PROCEDURE)
        {
          save_need_full_assumed_size = need_full_assumed_size;