lto-symtab.c (lto_symtab_resolve_symbols): Preffer decl with constructor over decl without.

	* lto-symtab.c (lto_symtab_resolve_symbols): Preffer decl with constructor
	over decl without.
	* cgraph.c (cgraph_remove_node): Clear also body of unanalyzed nodes.
	* cgraph.h (varpool_can_remove_if_no_refs): Handle external correctly.
	* cgraphunit.c (process_function_and_variable_attributes): Finalize 
	extrnal decls.
	(mark_functions_to_output): Also accept bodies for functions with clones.
	(output_in_order): Skip external vars.
	* lto-cgraph.c (lto_output_node): External functions are never in other
	partition.
	(lto_output_varpool_node): Likewise.
	* lto-streamer-out.c (lto_write_tree): Always use error_mark_nodes for
	forgotten initializers.
	* ipa.c (process_references): Handle external vars.
	(symtab_remove_unreachable_nodes): Update to handle external vars.
	(varpool_externally_visible_p): External vars are externally visible.
	* gimple-fold.c (can_refer_decl_in_current_unit_p): Update.
	* varpool.c (varpool_remove_node): Remove constructor.
	(decide_is_variable_needed): Handle externals.
	(varpool_remove_unreferenced_decls): Likewise.

	* lto-partition.c (add_references_to_partition): Handle external vars.
	(partition_varpool_node_p): Likewise.
	(lto_promote_cross_file_statics): Do not promote externals.

From-SVN: r187631

1 files changed, 15 insertions, 1 deletions

diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index a371c0a..c5efb7f 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -489,7 +489,21 @@ lto_symtab_resolve_symbols (void **slot)
       /* From variables that can prevail choose the largest one.  */
       if (!prevailing
 	  || tree_int_cst_lt (DECL_SIZE (prevailing->decl),
-			      DECL_SIZE (e->decl)))
+			      DECL_SIZE (e->decl))
+	  /* When variables are equivalent try to chose one that has useful
+	     DECL_INITIAL.  This makes sense for keyed vtables that are
+	     DECL_EXTERNAL but initialized.  In units that do not need them
+	     we replace the initializer by error_mark_node to conserve
+	     memory.
+
+	     We know that the vtable is keyed outside the LTO unit - otherwise
+	     the keyed instance would prevail.  We still can preserve useful
+	     info in the initializer.  */
+	  || (DECL_SIZE (prevailing->decl) == DECL_SIZE (e->decl)
+	      && (DECL_INITIAL (e->decl)
+		  && DECL_INITIAL (e->decl) != error_mark_node)
+	      && (!DECL_INITIAL (prevailing->decl)
+		  || DECL_INITIAL (prevailing->decl) == error_mark_node)))
 	prevailing = e;
     }