lto-symtab.c (lto_cgraph_replace_node): Handle aliases.

	* lto-symtab.c (lto_cgraph_replace_node): Handle aliases.
	(lto_symtab_resolve_can_prevail_p): Also alias of cgraph node
	with body can prevail.
	(lto_symtab_resolve_symbols): Use cgraph_get_node_or_alias.
	(lto_symtab_merge_cgraph_nodes_1): Do not remove nodes from aliases.
	* cgraph.c (cgraph_get_node_or_alias): New function.
	* cgraph.h (cgraph_get_node_or_alias): Declare.

From-SVN: r161877

gcc/ChangeLog

+2010-07-06  Jan Hubicka  <jh@suse.cz>
+
+	* lto-symtab.c (lto_cgraph_replace_node): Handle aliases.
+	(lto_symtab_resolve_can_prevail_p): Also alias of cgraph node
+	with body can prevail.
+	(lto_symtab_resolve_symbols): Use cgraph_get_node_or_alias.
+	(lto_symtab_merge_cgraph_nodes_1): Do not remove nodes from aliases.
+	* cgraph.c (cgraph_get_node_or_alias): New function.
+	* cgraph.h (cgraph_get_node_or_alias): Declare.
+
 2010-07-06  Kai Tietz  <kai.tietz@onevision.com>
 
 	* config/i386/i386.c (ix86_function_ms_hook_prologue): Enable x64

gcc/cgraph.c

@@ -604,6 +604,29 @@ cgraph_add_thunk (tree alias, tree decl, bool this_adjusting,
    is assigned.  */
 
 struct cgraph_node *
+cgraph_get_node_or_alias (tree decl)
+{
+  struct cgraph_node key, *node = NULL, **slot;
+
+  gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
+
+  if (!cgraph_hash)
+    return NULL;
+
+  key.decl = decl;
+
+  slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, &key,
+						 NO_INSERT);
+
+  if (slot && *slot)
+    node = *slot;
+  return node;
+}
+
+/* Returns the cgraph node assigned to DECL or NULL if no cgraph node
+   is assigned.  */
+
+struct cgraph_node *
 cgraph_get_node (tree decl)
 {
   struct cgraph_node key, *node = NULL, **slot;

gcc/lto-symtab.c

@@ -206,6 +206,24 @@ lto_cgraph_replace_node (struct cgraph_node *node,
 			 struct cgraph_node *prevailing_node)
 {
   struct cgraph_edge *e, *next;
+  bool no_aliases_please = false;
+
+  if (cgraph_dump_file)
+    {
+      fprintf (cgraph_dump_file, "Replacing cgraph node %s/%i by %s/%i"
+ 	       " for symbol %s\n",
+	       cgraph_node_name (node), node->uid,
+	       cgraph_node_name (prevailing_node),
+	       prevailing_node->uid,
+	       IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
+    }
+
+  if (prevailing_node->same_body_alias)
+    {
+      if (prevailing_node->thunk.thunk_p)
+	no_aliases_please = true;
+      prevailing_node = prevailing_node->same_body;
+    }
 
   /* Merge node flags.  */
   if (node->needed)
@@ -227,26 +245,36 @@ lto_cgraph_replace_node (struct cgraph_node *node,
   /* Redirect incomming references.  */
   ipa_clone_refering (prevailing_node, NULL, &node->ref_list);
 
-  if (node->same_body)
+  /* If we have aliases, redirect them to the prevailing node.  */
+  if (!node->same_body_alias && node->same_body)
     {
-      struct cgraph_node *alias;
+      struct cgraph_node *alias, *last;
+      /* We prevail aliases/tunks by a thunk.  This is doable but
+         would need thunk combination.  Hopefully no ABI changes will
+         every be crazy enough.  */
+      gcc_assert (!no_aliases_please);
 
       for (alias = node->same_body; alias; alias = alias->next)
-	if (DECL_ASSEMBLER_NAME_SET_P (alias->decl))
 	{
-	    lto_symtab_entry_t se
-	      = lto_symtab_get (DECL_ASSEMBLER_NAME (alias->decl));
-
-	    for (; se; se = se->next)
-	      if (se->node == node)
-		{
-		  se->node = NULL;
-		  break;
-		}
+	  last = alias;
+	  gcc_assert (alias->same_body_alias);
+	  alias->same_body = prevailing_node;
+	  alias->thunk.alias = prevailing_node->decl;
 	}
+      last->next = prevailing_node->same_body;
+      /* Node with aliases is prevailed by alias.
+	 We could handle this, but combining thunks together will be tricky.
+	 Hopefully this does not happen.  */
+      if (prevailing_node->same_body)
+	prevailing_node->same_body->previous = last;
+      prevailing_node->same_body = node->same_body;
+      node->same_body = NULL;
     }
 
   /* Finally remove the replaced node.  */
+  if (node->same_body_alias)
+    cgraph_remove_same_body_alias (node);
+  else
     cgraph_remove_node (node);
 }
 
@@ -433,7 +461,9 @@ lto_symtab_resolve_can_prevail_p (lto_symtab_entry_t e)
 
   /* For functions we need a non-discarded body.  */
   if (TREE_CODE (e->decl) == FUNCTION_DECL)
-    return (e->node && e->node->analyzed);
+    return (e->node
+	    && (e->node->analyzed
+	        || (e->node->same_body_alias && e->node->same_body->analyzed)));
 
   /* A variable should have a size.  */
   else if (TREE_CODE (e->decl) == VAR_DECL)
@@ -461,7 +491,7 @@ lto_symtab_resolve_symbols (void **slot)
   for (e = (lto_symtab_entry_t) *slot; e; e = e->next)
     {
       if (TREE_CODE (e->decl) == FUNCTION_DECL)
-	e->node = cgraph_get_node (e->decl);
+	e->node = cgraph_get_node_or_alias (e->decl);
       else if (TREE_CODE (e->decl) == VAR_DECL)
 	{
 	  e->vnode = varpool_get_node (e->decl);
@@ -751,22 +781,7 @@ lto_symtab_merge_cgraph_nodes_1 (void **slot, void *data ATTRIBUTE_UNUSED)
   for (e = prevailing->next; e; e = e->next)
     {
       if (e->node != NULL)
-	{
-	  if (e->node->decl != e->decl && e->node->same_body)
-	    {
-	      struct cgraph_node *alias;
-
-	      for (alias = e->node->same_body; alias; alias = alias->next)
-		if (alias->decl == e->decl)
-		  break;
-	      if (alias)
-		{
-		  cgraph_remove_same_body_alias (alias);
-		  continue;
-		}
-	    }
 	lto_cgraph_replace_node (e->node, prevailing->node);
-	}
       if (e->vnode != NULL)
 	lto_varpool_replace_node (e->vnode, prevailing->vnode);
     }