re PR lto/61886 (LTO breaks fread with _FORTIFY_SOURCE=2)

	PR ipa/61886
	* symtab.c (ultimate_transparent_alias_target): New inline function.
	(symbol_table::assembler_names_equal_p): New method; break out from ...
	(symbol_table::decl_assembler_name_equal): ... here.
	(symbol_table::change_decl_assembler_name): Also update names and
	translation links of transparent aliases.
	(symtab_node::dump_base): Dump transparent_alias.
	(symtab_node::verify_base): Implement basic transparent alias
	verification.
	(symtab_node::make_decl_local): Support localization of weakrefs;
	recurse to transparent aliases; set TREE_STATIC.
	(symtab_node::ultimate_alias_target_1): Handle visibility of
	transparent aliases.
	(symtab_node::resolve_alias): New parmaeter transparent; handle
	transparent aliases; recurse to aliases of aliases to fix comdat
	groups.
	(symtab_node::get_partitioning_class): Handle transparent aliases.
	* ipa-visibility.c (cgraph_externally_visible_p,
	varpool_node::externally_visible_p): Visibility of transparent alias
	depends on its target.
	(function_and_variable_visibility): Do not tweak visibility of
	transparent laiases.
	(function_and_variable_visibility): Likewise.
	* ipa.c (symbol_table::remove_unreachable_nodes): Clear
	transparent_alias flag.
	* alias.c (cgraph_node::create_alias, cgraph_node::get_availability):
	Support transparent aliases.
	* cgraph.h (symtab_node): Update prototype of resolve_alias;
	add transparent_alias flag.
	(symbol_table: Add assembler_names_equal_p.
	(symtab_node::real_symbol_p): Skip transparent aliases.
	* cgraphunit.c (cgraph_node::reset): Reset transparent_alias flag.
	(handle_alias_pairs): Set transparent_alias for weakref.
	(cgraph_node::assemble_thunks_and_aliases): Do not asemble transparent
	aliases.
	* lto-cgraph.c (lto_output_node): When outputting same_comdat_group
	skip symbols not put into boundary; stream transparent_alias.
	(lto_output_varpool_node): Likewise.
	(input_overwrite_node, input_varpool_node): Stream transparent alias.
	* varpool.c (ctor_for_folding, varpool_node::get_availability,
	varpool_node::assemble_aliases,
	symbol_table::remove_unreferenced_decls): Handle transparent aliase.
	(varpool_node::create_alias): Set transparent_alias.

	* lto-partition.c (add_symbol_to_partition_1, contained_in_symbol,
	rename_statics, rename_statics): Handle transparent aliases.

From-SVN: r231373

1 files changed, 35 insertions, 22 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index c8b3ab8..de67c4f 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -13423,6 +13423,12 @@ gimple_canonical_types_compatible_p (const_tree t1, const_tree t2,
       {
 	tree f1, f2;
 
+	/* Don't try to compare variants of an incomplete type, before
+	   TYPE_FIELDS has been copied around.  */
+	if (!COMPLETE_TYPE_P (t1) && !COMPLETE_TYPE_P (t2))
+	  return true;
+
+
 	if (TYPE_REVERSE_STORAGE_ORDER (t1) != TYPE_REVERSE_STORAGE_ORDER (t2))
 	  return false;
 
@@ -13709,28 +13715,35 @@ verify_type (const_tree t)
 	}
     }
   else if (RECORD_OR_UNION_TYPE_P (t))
-    for (tree fld = TYPE_FIELDS (t); fld; fld = TREE_CHAIN (fld))
-      {
-	/* TODO: verify properties of decls.  */
-	if (TREE_CODE (fld) == FIELD_DECL)
-	  ;
-	else if (TREE_CODE (fld) == TYPE_DECL)
-	  ;
-	else if (TREE_CODE (fld) == CONST_DECL)
-	  ;
-	else if (TREE_CODE (fld) == VAR_DECL)
-	  ;
-	else if (TREE_CODE (fld) == TEMPLATE_DECL)
-	  ;
-	else if (TREE_CODE (fld) == USING_DECL)
-	  ;
-	else
-	  {
-	    error ("Wrong tree in TYPE_FIELDS list");
-	    debug_tree (fld);
-	    error_found = true;
-	  }
-      }
+    {
+      if (TYPE_FIELDS (t) && !COMPLETE_TYPE_P (t) && in_lto_p)
+	{
+	  error ("TYPE_FIELDS defined in incomplete type");
+	  error_found = true;
+	}
+      for (tree fld = TYPE_FIELDS (t); fld; fld = TREE_CHAIN (fld))
+	{
+	  /* TODO: verify properties of decls.  */
+	  if (TREE_CODE (fld) == FIELD_DECL)
+	    ;
+	  else if (TREE_CODE (fld) == TYPE_DECL)
+	    ;
+	  else if (TREE_CODE (fld) == CONST_DECL)
+	    ;
+	  else if (TREE_CODE (fld) == VAR_DECL)
+	    ;
+	  else if (TREE_CODE (fld) == TEMPLATE_DECL)
+	    ;
+	  else if (TREE_CODE (fld) == USING_DECL)
+	    ;
+	  else
+	    {
+	      error ("Wrong tree in TYPE_FIELDS list");
+	      debug_tree (fld);
+	      error_found = true;
+	    }
+	}
+    }
   else if (TREE_CODE (t) == INTEGER_TYPE
 	   || TREE_CODE (t) == BOOLEAN_TYPE
 	   || TREE_CODE (t) == OFFSET_TYPE