[Bug fortran/53086] [4.8 Regression] 416.gamess in SPEC CPU 2006 miscompiled

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53086

--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-24 09:29:10 UTC ---
A "fix" would be for example

Index: gcc/expr.c
===================================================================
--- gcc/expr.c  (revision 186757)
+++ gcc/expr.c  (working copy)
@@ -6809,7 +6809,8 @@ array_at_struct_end_p (tree ref)

   /* If the reference is based on a declared entity, the size of the array
      is constrained by its given domain.  */
-  if (DECL_P (ref))
+  if (DECL_P (ref)
+      && !DECL_COMMON (ref))
     return false;

   return true;

of course other parts of the compiler will still be affected by this.
If the Frontend wants to reliably make this work then it has to use
an open-ended TYPE_DOMAIN for the array (and then lay out the underlying
decl manually).  Not sure if that's easy though (the incomplete type might
trigger ICEs in other places).