(c_build_type_variant): Don't change TYPE_MAIN_VARIANT of new type.

From-SVN: r7427

diff --git a/gcc/c-common.c b/gcc/c-common.c
index 425f92e..d09bf41 100644 (file)
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -1972,14 +1972,16 @@ c_build_type_variant (type, constp, volatilep)
 {
   if (TREE_CODE (type) == ARRAY_TYPE)
     {
-      tree real_main_variant = TYPE_MAIN_VARIANT (type);
-
       push_obstacks (TYPE_OBSTACK (type), TYPE_OBSTACK (type));
       type = build_array_type (c_build_type_variant (TREE_TYPE (type),
                                                     constp, volatilep),
                               TYPE_DOMAIN (type));
-      TYPE_MAIN_VARIANT (type) = real_main_variant;
       pop_obstacks ();
+
+      /* If the old TYPE had variants, we lose them here.  However,
+        since the new TYPE can be in the permanent obstack and the
+        old one may not be, preserving this chain would cause permanent
+        objects to point to non-permanent ones.  */
     }
   return build_type_variant (type, constp, volatilep);
 }