ipa.c (symbol_table::remove_unreachable_nodes): Avoid releasing bodies of thunks; comment on why.

	* ipa.c (symbol_table::remove_unreachable_nodes): Avoid releasing
	bodies of thunks; comment on why.
	* symtab.c (symtab_node::get_partitioning_class): Aliases of extern
	symbols are extern.

From-SVN: r220630

gcc/ChangeLog

+2015-02-11  Jan Hubicka  <hubicka@ucw.cz>
+
+	* ipa.c (symbol_table::remove_unreachable_nodes): Avoid releasing
+	bodies of thunks; comment on why.
+	* symtab.c (symtab_node::get_partitioning_class): Aliases of extern
+	symbols are extern.
+
 2015-02-11  Richard Henderson  <rth@redhat.com>
 
 	PR sanitize/65000

gcc/ipa.c

@@ -537,7 +537,13 @@ symbol_table::remove_unreachable_nodes (FILE *file)
       /* If node is unreachable, remove its body.  */
       else if (!reachable.contains (node))
         {
-	  if (!body_needed_for_clonning.contains (node->decl))
+	  /* We keep definitions of thunks and aliases in the boundary so
+	     we can walk to the ultimate alias targets and function symbols
+	     reliably.  */
+	  if (node->alias || node->thunk.thunk_p)
+	    ;
+	  else if (!body_needed_for_clonning.contains (node->decl)
+	      && !node->alias && !node->thunk.thunk_p)
 	    node->release_body ();
 	  else if (!node->clone_of)
 	    gcc_assert (in_lto_p || DECL_RESULT (node->decl));

gcc/symtab.c

@@ -1779,6 +1779,8 @@ symtab_node::get_partitioning_class (void)
 
   if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
     {
+      if (alias && definition && !ultimate_alias_target ()->definition)
+	return SYMBOL_EXTERNAL;
       /* Constant pool references use local symbol names that can not
          be promoted global.  We should never put into a constant pool
          objects that can not be duplicated across partitions.  */
@@ -1790,7 +1792,7 @@ symtab_node::get_partitioning_class (void)
      Handle them as external; compute_ltrans_boundary take care to make
      proper things to happen (i.e. to make them appear in the boundary but
      with body streamed, so clone can me materialized).  */
-  else if (!dyn_cast <cgraph_node *> (this)->definition)
+  else if (!dyn_cast <cgraph_node *> (this)->function_symbol ()->definition)
     return SYMBOL_EXTERNAL;
 
   /* Linker discardable symbols are duplicated to every use unless they are