[Bug fortran/68283] [5/6 Regression] ice: gfc_variable_attr(): Bad array reference

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68283

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pault at gcc dot gnu.org,
                   |                            |tkoenig at gcc dot gnu.org

--- Comment #12 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
The block

            for (n = 0; n < ref->u.ar.as->rank; n++)
              {
                int errors;
                gfc_get_errors (NULL, &errors);
                if (((ref->u.ar.start[n]
                      && ref->u.ar.start[n]->ts.type == BT_UNKNOWN)
                     ||
                     (ref->u.ar.end[n]
                      && ref->u.ar.end[n]->ts.type == BT_UNKNOWN)
                     ||
                     (ref->u.ar.stride[n]
                      && ref->u.ar.stride[n]->ts.type == BT_UNKNOWN))
                    && errors > 0)
                  break;
              }
            if (n == ref->u.ar.as->rank)
              gfc_internal_error ("gfc_variable_attr(): Bad array reference");

in gcc/fortran/primary.c (introduced at r221955) looks fishy, CCed Paul.

It is not accessed if the code is compiled with -fno-frontend-optimize, CCed
Thomas.

The patch

--- ../_clean/gcc/fortran/primary.c     2015-10-18 13:07:28.000000000 +0200
+++ gcc/fortran/primary.c       2015-11-12 11:15:02.000000000 +0100
@@ -2194,7 +2194,7 @@ check_substring:
 symbol_attribute
 gfc_variable_attr (gfc_expr *expr, gfc_typespec *ts)
 {
-  int dimension, codimension, pointer, allocatable, target, n;
+  int dimension, codimension, pointer, allocatable, target;
   symbol_attribute attr;
   gfc_ref *ref;
   gfc_symbol *sym;
@@ -2253,22 +2253,9 @@ gfc_variable_attr (gfc_expr *expr, gfc_t
          case AR_UNKNOWN:
            /* If any of start, end or stride is not integer, there will
               already have been an error issued.  */
-           for (n = 0; n < ref->u.ar.as->rank; n++)
-             {
-               int errors;
-               gfc_get_errors (NULL, &errors);
-               if (((ref->u.ar.start[n]
-                     && ref->u.ar.start[n]->ts.type == BT_UNKNOWN)
-                    ||
-                    (ref->u.ar.end[n]
-                     && ref->u.ar.end[n]->ts.type == BT_UNKNOWN)
-                    ||
-                    (ref->u.ar.stride[n]
-                     && ref->u.ar.stride[n]->ts.type == BT_UNKNOWN))
-                   && errors > 0)
-                 break;
-             }
-           if (n == ref->u.ar.as->rank)
+           int errors;
+           gfc_get_errors (NULL, &errors);
+           if (errors == 0)
              gfc_internal_error ("gfc_variable_attr(): Bad array reference");
          }

fixes the PR without any regression (I have left the comment which may be
updated).