[Bug fortran/105230] [9/10/11/12 Regression] ICE in find_array_section, at fortran/expr.cc:1634

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105230

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-04-11
                 CC|                            |kargl at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from kargl at gcc dot gnu.org ---
Started with 22015e77d3e4.

I cannot work out the logic here in expr.cc:1595-1603


          if ((begin && begin->expr_type != EXPR_CONSTANT)
              || (finish && finish->expr_type != EXPR_CONSTANT)
              || (step && step->expr_type != EXPR_CONSTANT)
              || (!begin && !lower)
              || (!finish && !upper))
            {
              t = false;
              goto cleanup;
            }

upper is NULL and later in 1634 it is dereferenced.  This patch fixes
the problem, but the above logic likely needs fixing.

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index 86d61fed302..4fcdf009b4b 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -1630,6 +1630,11 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
          if (ref->u.ar.dimen_type[d] == DIMEN_ELEMENT)
            mpz_set (end [d], begin->value.integer);

+         if (!upper || !lower)
+           {
+             t = false;
+             goto cleanup;
+           }
          /* Check the bounds.  */
          if (mpz_cmp (ctr[d], upper->value.integer) > 0
              || mpz_cmp (end[d], upper->value.integer) > 0