[C++ PATCH] some name lookup cleanups

[Nathan Sidwell <nathan at acm dot org>]

We have a funky combined lookup & ADL, called exactly twice to find 
operator new.  Let's break that apart to separate lookups for clarity.

struct scope_binding is now dead, having been consumed by name_lookup.

A stale declaration of do_using_directive was still there and confused 
libcp1plugin into thinking it could be called.

A couple of places used is_overloaded_fn when plain OVL_P could be used.

cp_emit_debug_info_for_using didn;t know about the new 
MAYBE_BASELINK_FUNCTIONS

nathan
--
Nathan Sidwell

2017-05-26  Nathan Sidwell  <nathan@acm.org>

	gcc/cp/
	* call.c (build_operator_new_call): Do namelookup and ADL here.
	(build_new_op_1): Likewise.
	* name-lookup.h (lookup_function_nonclass): Delete declaration.
	(do_using_directive): Likewise.
	* name-lookup.c (set_namespace_binding, push_local_binding): Don't
	declare early.
	(struct scope_binding): Delete.
	(EMPTY_SCOPE_BINDING): Delete.
	(set_decl_namespace): Use OVL_P.
	(finish_local_using_decl): Lose unnecesary checks.
	(lookup_function_nonclass): Delete.
	(cp_emit_debug_info_for_using): Use MAYBE_BASELINK_P.

	libcc1/
	* libcp1plugin.cc (plugin_add_using_namespace): Call
	finish_namespace_using_directive.

Index: gcc/cp/call.c
===================================================================
--- gcc/cp/call.c	(revision 248517)
+++ gcc/cp/call.c	(working copy)
@@ -4318,7 +4318,8 @@ build_operator_new_call (tree fnname, ve
        up in the global scope.
 
      we disregard block-scope declarations of "operator new".  */
-  fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
+  fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0);
+  fns = lookup_arg_dependent (fnname, fns, *args);
 
   if (align_arg)
     {
@@ -5628,11 +5629,13 @@ build_new_op_1 (location_t loc, enum tre
   /* Add namespace-scope operators to the list of functions to
      consider.  */
   if (!memonly)
-    add_candidates (lookup_function_nonclass (fnname, arglist,
-					      /*block_p=*/true),
-		    NULL_TREE, arglist, NULL_TREE,
-		    NULL_TREE, false, NULL_TREE, NULL_TREE,
-		    flags, &candidates, complain);
+    {
+      tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0);
+      fns = lookup_arg_dependent (fnname, fns, arglist);
+      add_candidates (fns, NULL_TREE, arglist, NULL_TREE,
+		      NULL_TREE, false, NULL_TREE, NULL_TREE,
+		      flags, &candidates, complain);
+    }
 
   args[0] = arg1;
   args[1] = arg2;
Index: gcc/cp/name-lookup.c
===================================================================
--- gcc/cp/name-lookup.c	(revision 248517)
+++ gcc/cp/name-lookup.c	(working copy)
@@ -37,16 +37,6 @@ static cxx_binding *cxx_binding_make (tr
 static cp_binding_level *innermost_nonclass_level (void);
 static void set_identifier_type_value_with_scope (tree id, tree decl,
 						  cp_binding_level *b);
-static void set_namespace_binding (tree scope, tree name, tree val);
-static void push_local_binding (tree, tree, bool);
-
-/* The bindings for a particular name in a particular scope.  */
-
-struct scope_binding {
-  tree value;
-  tree type;
-};
-#define EMPTY_SCOPE_BINDING { NULL_TREE, NULL_TREE }
 
 /* Create a local binding level for NAME.  */
 
@@ -4243,7 +4233,7 @@ set_decl_namespace (tree decl, tree scop
       print_candidates (old);
       return;
     }
-  if (!is_overloaded_fn (decl))
+  if (!OVL_P (decl))
     {
       /* We might have found OLD in an inline namespace inside SCOPE.  */
       if (TREE_CODE (decl) == TREE_CODE (old))
@@ -4254,7 +4244,7 @@ set_decl_namespace (tree decl, tree scop
       return;
     }
   /* Since decl is a function, old should contain a function decl.  */
-  if (!is_overloaded_fn (old))
+  if (!OVL_P (old))
     goto complain;
   /* We handle these in check_explicit_instantiation_namespace.  */
   if (processing_explicit_instantiation)
@@ -4411,6 +4401,7 @@ handle_namespace_attrs (tree ns, tree at
 
   return saw_vis;
 }
+
 /* Temporarily set the namespace for the current declaration.  */
 
 void
@@ -4544,10 +4535,7 @@ finish_local_using_decl (tree decl, tree
   if (decl == NULL_TREE)
     return;
 
-  gcc_assert (building_stmt_list_p ());
-  if (building_stmt_list_p ()
-      && at_function_scope_p ())
-    add_decl_expr (decl);
+  add_decl_expr (decl);
 
   cxx_binding *binding = find_local_binding (current_binding_level, name);
   tree value = binding ? binding->value : NULL_TREE;
@@ -5308,15 +5296,6 @@ lookup_name_nonclass (tree name)
 }
 
 tree
-lookup_function_nonclass (tree name, vec<tree, va_gc> *args, bool block_p)
-{
-  return
-    lookup_arg_dependent (name,
-			  lookup_name_real (name, 0, 1, block_p, 0, 0),
-			  args);
-}
-
-tree
 lookup_name (tree name)
 {
   return lookup_name_real (name, 0, 0, /*block_p=*/true, 0, 0);
@@ -6277,8 +6256,7 @@ cp_emit_debug_info_for_using (tree t, tr
   if (context == global_namespace)
     context = NULL_TREE;
 
-  if (BASELINK_P (t))
-    t = BASELINK_FUNCTIONS (t);
+  t = MAYBE_BASELINK_FUNCTIONS (t);
 
   /* FIXME: Handle TEMPLATE_DECLs.  */
   for (lkp_iterator iter (t); iter; ++iter)
Index: gcc/cp/name-lookup.h
===================================================================
--- gcc/cp/name-lookup.h	(revision 248517)
+++ gcc/cp/name-lookup.h	(working copy)
@@ -311,7 +311,6 @@ extern void set_global_binding (tree id,
 extern tree lookup_qualified_name (tree, tree, int, bool, /*hidden*/bool = false);
 extern tree lookup_name_nonclass (tree);
 extern bool is_local_extern (tree);
-extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool);
 extern bool pushdecl_class_level (tree);
 extern tree pushdecl_namespace_level (tree, bool);
 extern bool push_class_level_binding (tree, tree);
@@ -323,7 +322,6 @@ extern void push_decl_namespace (tree);
 extern void pop_decl_namespace (void);
 extern void do_namespace_alias (tree, tree);
 extern tree do_class_using_decl (tree, tree);
-extern void do_using_directive (tree);
 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *);
 extern tree innermost_non_namespace_value (tree);
 extern cxx_binding *outer_binding (tree, cxx_binding *, bool);
Index: libcc1/libcp1plugin.cc
===================================================================
--- libcc1/libcp1plugin.cc	(revision 248517)
+++ libcc1/libcp1plugin.cc	(working copy)
@@ -946,7 +946,7 @@ plugin_add_using_namespace (cc1_plugin::
 
   gcc_assert (TREE_CODE (used_ns) == NAMESPACE_DECL);
 
-  do_using_directive (used_ns);
+  finish_namespace_using_directive (used_ns, NULL_TREE);
 
   return 1;
 }