[gfortran] Fix PR 13201

[Tobias Schlüter <tobias dot schlueter at physik dot uni-muenchen dot de>]

My previous fixlet for PR 13201 didn't catch the general case of a
parameter array not having a constant shape. This followup patch fixes
that omission.

Looking the patch over, I think a better name than 'constant shape' is
probably called for. I'm open to suggestions how to concisely say
'explicit shape, determined at compile time by means of constants'. I
will definitely enhance the comment in array.c.

Built and tested on i686-pc-linux.

- Tobi

2004-07-09  Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>
	
	PR fortran/13201
	* resolve.c (resolve_symbol): Verify that the shape of a
	parameter array is not only explicit, but also constant.
	* array.c (gfc_is_constant_shape): New function.
	* gfortran.h (gfc_is_constant_shape): Add prototype.

Index: resolve.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fortran/resolve.c,v
retrieving revision 1.9
diff -u -p -r1.9 resolve.c
--- resolve.c   9 Jul 2004 14:53:39 -0000       1.9
+++ resolve.c   9 Jul 2004 20:23:42 -0000
@@ -3745,12 +3745,14 @@ resolve_symbol (gfc_symbol * sym)
       return;
     }

-  if (sym->attr.flavor == FL_PARAMETER
-      && sym->as != NULL && sym->as->type != AS_EXPLICIT)
+  /* A parameter array's shape needs to be constant.  */
+
+  if (sym->attr.flavor == FL_PARAMETER && sym->as != NULL
+      && !gfc_is_constant_shape (sym->as))
     {
-      gfc_error ("Parameter array '%s' at %L must have an explicit shape",
-                sym->name, &sym->declared_at);
-      return;
+      gfc_error ("Parameter array '%s' at %L must have an explicit, "
+                "constant shape", sym->name, &sym->declared_at);
+         return;
     }

   /* Make sure that character string variables with assumed length are
Index: array.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fortran/array.c,v
retrieving revision 1.5
diff -u -p -r1.5 array.c
--- array.c     21 Jun 2004 17:16:25 -0000      1.5
+++ array.c     9 Jul 2004 20:23:42 -0000
@@ -1973,3 +1973,22 @@ gfc_find_array_ref (gfc_expr * e)

   return &ref->u.ar;
 }
+
+
+/* Find out if an array shape is constant.  */
+
+int
+gfc_is_constant_shape (gfc_array_spec *as)
+{
+  int i;
+
+  if (as->type != AS_EXPLICIT)
+    return 0;
+
+  for (i = 0; i < as->rank; i++)
+    if (!gfc_is_constant_expr (as->lower[i])
+       || !gfc_is_constant_expr (as->upper[i]))
+      return 0;
+
+  return 1;
+}
Index: gfortran.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fortran/gfortran.h,v
retrieving revision 1.17
diff -u -p -r1.17 gfortran.h
--- gfortran.h  4 Jul 2004 17:00:11 -0000       1.17
+++ gfortran.h  9 Jul 2004 20:23:42 -0000
@@ -1645,6 +1645,7 @@ void gfc_insert_constructor (gfc_expr *,
 gfc_constructor *gfc_get_constructor (void);
 tree gfc_conv_array_initializer (tree type, gfc_expr * expr);
 try spec_size (gfc_array_spec *, mpz_t *);
+int gfc_is_constant_shape (gfc_array_spec *);

 /* interface.c -- FIXME: some of these should be in symbol.c */
 void gfc_free_interface (gfc_interface *);