re PR target/44643 ([avr] ICE in c-typeck.c)

	PR target/44643
	* config/avr/avr.c (avr_insert_attributes): Leave TREE_READONLY
	alone. Error if non-const data has attribute progmem.

From-SVN: r172415

gcc/ChangeLog

+2011-04-14  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/44643
+	* config/avr/avr.c (avr_insert_attributes): Leave TREE_READONLY
+	alone. Error if non-const data has attribute progmem.
+
 2011-04-13  Nathan Froyd  <froydnj@codesourcery.com>
 
 	* tree.h (struct tree_constructor): Include tree_typed instead of

gcc/config/avr/avr.c

@@ -5149,14 +5149,20 @@ avr_insert_attributes (tree node, tree *attributes)
       && (TREE_STATIC (node) || DECL_EXTERNAL (node))
       && avr_progmem_p (node, *attributes))
     {
-      static const char dsec[] = ".progmem.data";
-      *attributes = tree_cons (get_identifier ("section"),
-		build_tree_list (NULL, build_string (strlen (dsec), dsec)),
-		*attributes);
-
-      /* ??? This seems sketchy.  Why can't the user declare the
-	 thing const in the first place?  */
-      TREE_READONLY (node) = 1;
+      if (TREE_READONLY (node)) 
+        {
+          static const char dsec[] = ".progmem.data";
+
+          *attributes = tree_cons (get_identifier ("section"),
+                                   build_tree_list (NULL, build_string (strlen (dsec), dsec)),
+                                   *attributes);
+        }
+      else
+        {
+          error ("variable %q+D must be const in order to be put into"
+                 " read-only section by means of %<__attribute__((progmem))%>",
+                 node);
+        }
     }
 }