c++: Cleanup some decl pushing apis

In cleaning up local decl handling, here's an initial patch that takes
advantage of C++'s default args for the is_friend parm of pushdecl,
duplicate_decls and push_template_decl_real and the scope & tpl_header
parms of xref_tag.  Then many of the calls simply not mention these.
I also rename push_template_decl_real to push_template_decl, deleting
the original forwarding function.  This'll make my later patches
changing their types less intrusive.  There are 2 functional changes:

1) push_template_decl requires is_friend to be correct, it doesn't go
checking for a friend function (an assert is added).

2) debug_overload prints out Hidden and Using markers for the overload set.

	gcc/cp/
	* cp-tree.h (duplicate_decls): Default is_friend to false.
	(xref_tag): Default tag_scope & tpl_header_p to ts_current & false.
	(push_template_decl_real): Default is_friend to false.  Rename to
	...
	(push_template_decl): ... here.  Delete original decl.
	* name-lookup.h (pushdecl_namespace_level): Default is_friend to
	false.
	(pushtag): Default tag_scope to ts_current.
	* coroutines.cc (morph_fn_to_coro): Drop default args to xref_tag.
	* decl.c (start_decl): Drop default args to duplicate_decls.
	(start_enum): Drop default arg to pushtag & xref_tag.
	(start_preparsed_function): Pass DECL_FRIEND_P to
	push_template_decl.
	(grokmethod): Likewise.
	* friend.c (do_friend): Rename push_template_decl_real calls.
	* lambda.c (begin_lamnbda_type): Drop default args to xref_tag.
	(vla_capture_type): Likewise.
	* name-lookup.c (maybe_process_template_type_declaration): Rename
	push_template_decl_real call.
	(pushdecl_top_level_and_finish): Drop default arg to
	pushdecl_namespace_level.
	* pt.c (push_template_decl_real): Assert no surprising friend
	functions.  Rename to ...
	(push_template_decl): ... here.  Delete original function.
	(lookup_template_class_1): Drop default args from pushtag.
	(instantiate_class_template_1): Likewise.
	* ptree.c (debug_overload): Print hidden and using markers.
	* rtti.c (init_rtti_processing): Drop refault args from xref_tag.
	(build_dynamic_cast_1, tinfo_base_init): Likewise.
	* semantics.c (begin_class_definition): Drop default args to
	pushtag.
	gcc/objcp/
	* objcp-decl.c (objcp_start_struct): Drop default args to
	xref_tag.
	(objcp_xref_tag): Likewise.
	libcc1/
	* libcp1plugin.cc (supplement_binding): Drop default args to
	duplicate_decls.
	(safe_pushtag): Drop scope parm.  Drop default args to pushtag.
	(safe_pushdecl_maybe_friend): Rename to ...
	(safe_pushdecl): ... here. Drop is_friend parm.  Drop default args
	to pushdecl.
	(plugin_build_decl): Adjust safe_pushdecl & safe_pushtag calls.
	(plugin_build_constant): Adjust safe_pushdecl call.

12 files changed, 43 insertions, 49 deletions

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 898b88b..ba81345 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -4011,7 +4011,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
   /* 2. Types we need to define or look up.  */
 
   tree fr_name = get_fn_local_identifier (orig, "frame");
-  tree coro_frame_type = xref_tag (record_type, fr_name, ts_current, false);
+  tree coro_frame_type = xref_tag (record_type, fr_name);
   DECL_CONTEXT (TYPE_NAME (coro_frame_type)) = current_scope ();
   tree coro_frame_ptr = build_pointer_type (coro_frame_type);
   tree act_des_fn_type
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 029a165..3ae4874 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6461,7 +6461,8 @@ extern void note_iteration_stmt_body_end	(bool);
 extern void determine_local_discriminator	(tree);
 extern int decls_match				(tree, tree, bool = true);
 extern bool maybe_version_functions		(tree, tree, bool);
-extern tree duplicate_decls			(tree, tree, bool);
+extern tree duplicate_decls			(tree, tree,
+						 bool is_friend = false);
 extern tree declare_local_label			(tree);
 extern tree define_label			(location_t, tree);
 extern void check_goto				(tree);
@@ -6501,7 +6502,9 @@ extern tree get_scope_of_declarator		(const cp_declarator *);
 extern void grok_special_member_properties	(tree);
 extern bool grok_ctor_properties		(const_tree, const_tree);
 extern bool grok_op_properties			(tree, bool);
-extern tree xref_tag				(enum tag_types, tree, tag_scope, bool);
+extern tree xref_tag				(tag_types, tree,
+						 tag_scope = ts_current,
+						 bool tpl_header_p = false);
 extern void xref_basetypes			(tree, tree);
 extern tree start_enum				(tree, tree, tree, tree, bool, bool *);
 extern void finish_enum_value_list		(tree);
@@ -6849,8 +6852,7 @@ extern void end_template_parm_list		(void);
 extern void end_template_decl			(void);
 extern tree maybe_update_decl_type		(tree, tree);
 extern bool check_default_tmpl_args             (tree, tree, bool, bool, int);
-extern tree push_template_decl			(tree);
-extern tree push_template_decl_real		(tree, bool);
+extern tree push_template_decl			(tree, bool is_friend = false);
 extern tree add_inherited_template_parms	(tree, tree);
 extern void template_parm_level_and_index	(tree, int*, int*);
 extern bool redeclare_class_template		(tree, tree, tree);
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index f3fdfe3..6019051 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5361,8 +5361,7 @@ start_decl (const cp_declarator *declarator,
 		 about this situation, and so we check here.  */
 	      if (initialized && DECL_INITIALIZED_IN_CLASS_P (field))
 		error ("duplicate initialization of %qD", decl);
-	      field = duplicate_decls (decl, field,
-				       /*newdecl_is_friend=*/false);
+	      field = duplicate_decls (decl, field);
 	      if (field == error_mark_node)
 		return error_mark_node;
 	      else if (field)
@@ -5376,8 +5375,7 @@ start_decl (const cp_declarator *declarator,
 				      ? current_template_parms
 				      : NULL_TREE);
 	  if (field && field != error_mark_node
-	      && duplicate_decls (decl, field,
-				 /*newdecl_is_friend=*/false))
+	      && duplicate_decls (decl, field))
 	    decl = field;
 	}
 
@@ -15476,7 +15474,7 @@ start_enum (tree name, tree enumtype, tree underlying_type,
 	  || TREE_CODE (enumtype) != ENUMERAL_TYPE)
 	{
 	  enumtype = cxx_make_type (ENUMERAL_TYPE);
-	  enumtype = pushtag (name, enumtype, /*tag_scope=*/ts_current);
+	  enumtype = pushtag (name, enumtype);
 
 	  /* std::byte aliases anything.  */
 	  if (enumtype != error_mark_node
@@ -15485,8 +15483,7 @@ start_enum (tree name, tree enumtype, tree underlying_type,
 	    TYPE_ALIAS_SET (enumtype) = 0;
 	}
       else
-	  enumtype = xref_tag (enum_type, name, /*tag_scope=*/ts_current,
-			       false);
+	  enumtype = xref_tag (enum_type, name);
 
       if (enumtype == error_mark_node)
 	return error_mark_node;
@@ -16257,7 +16254,7 @@ start_preparsed_function (tree decl1, tree attrs, int flags)
      by push_nested_class.)  */
   if (processing_template_decl)
     {
-      tree newdecl1 = push_template_decl (decl1);
+      tree newdecl1 = push_template_decl (decl1, DECL_FRIEND_P (decl1));
       if (newdecl1 == error_mark_node)
 	{
 	  if (ctype || DECL_STATIC_FUNCTION_P (decl1))
@@ -17362,7 +17359,7 @@ grokmethod (cp_decl_specifier_seq *declspecs,
   /* We process method specializations in finish_struct_1.  */
   if (processing_template_decl && !DECL_TEMPLATE_SPECIALIZATION (fndecl))
     {
-      fndecl = push_template_decl (fndecl);
+      fndecl = push_template_decl (fndecl, DECL_FRIEND_P (fndecl));
       if (fndecl == error_mark_node)
 	return fndecl;
     }
diff --git a/gcc/cp/friend.c b/gcc/cp/friend.c
index fa20a93..e484134 100644
--- a/gcc/cp/friend.c
+++ b/gcc/cp/friend.c
@@ -558,7 +558,7 @@ do_friend (tree ctype, tree declarator, tree decl,
 	  else if (class_template_depth)
 	    /* We rely on tsubst_friend_function to check the
 	       validity of the declaration later.  */
-	    decl = push_template_decl_real (decl, /*is_friend=*/true);
+	    decl = push_template_decl (decl, /*is_friend=*/true);
 	  else
 	    decl = check_classfn (ctype, decl,
 				  template_member_p
@@ -611,7 +611,7 @@ do_friend (tree ctype, tree declarator, tree decl,
 	       general, such a declaration depends on template
 	       parameters.  Instead, we call pushdecl when the class
 	       is instantiated.  */
-	    decl = push_template_decl_real (decl, /*is_friend=*/true);
+	    decl = push_template_decl (decl, /*is_friend=*/true);
 	  else if (current_function_decl)
 	    /* pushdecl will check there's a local decl already.  */
 	    decl = pushdecl (decl, /*is_friend=*/true);
diff --git a/gcc/cp/lambda.c b/gcc/cp/lambda.c
index 7fccccc..07a5401 100644
--- a/gcc/cp/lambda.c
+++ b/gcc/cp/lambda.c
@@ -134,8 +134,7 @@ begin_lambda_type (tree lambda)
   IDENTIFIER_LAMBDA_P (name) = true;
 
   /* Create the new RECORD_TYPE for this lambda.  */
-  tree type = xref_tag (/*tag_code=*/record_type, name,
-			/*scope=*/ts_current, /*template_header_p=*/false);
+  tree type = xref_tag (/*tag_code=*/record_type, name);
   if (type == error_mark_node)
     return error_mark_node;
 
@@ -476,7 +475,7 @@ static GTY(()) tree max_id;
 static tree
 vla_capture_type (tree array_type)
 {
-  tree type = xref_tag (record_type, make_anon_name (), ts_current, false);
+  tree type = xref_tag (record_type, make_anon_name ());
   xref_basetypes (type, NULL_TREE);
   type = begin_class_definition (type);
   if (!ptr_id)
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index bbeaf64..e7764ab 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -6723,11 +6723,11 @@ maybe_process_template_type_declaration (tree type, int is_friend,
 
       if (processing_template_decl)
 	{
-	  /* This may change after the call to
-	     push_template_decl_real, but we want the original value.  */
+	  /* This may change after the call to push_template_decl, but
+	     we want the original value.  */
 	  tree name = DECL_NAME (decl);
 
-	  decl = push_template_decl_real (decl, is_friend);
+	  decl = push_template_decl (decl, is_friend);
 	  if (decl == error_mark_node)
 	    return error_mark_node;
 
@@ -7301,7 +7301,7 @@ pushdecl_top_level_and_finish (tree x, tree init)
 {
   bool subtime = timevar_cond_start (TV_NAME_LOOKUP);
   do_push_to_top_level ();
-  x = pushdecl_namespace_level (x, false);
+  x = pushdecl_namespace_level (x);
   cp_finish_decl (x, init, false, NULL_TREE, 0);
   do_pop_from_top_level ();
   timevar_cond_stop (TV_NAME_LOOKUP, subtime);
diff --git a/gcc/cp/name-lookup.h b/gcc/cp/name-lookup.h
index 5d2d364f..76ec8f2 100644
--- a/gcc/cp/name-lookup.h
+++ b/gcc/cp/name-lookup.h
@@ -341,7 +341,7 @@ extern tree lookup_qualified_name (tree scope, const char *name,
 				   bool = true);
 extern bool is_local_extern (tree);
 extern bool pushdecl_class_level (tree);
-extern tree pushdecl_namespace_level (tree, bool);
+extern tree pushdecl_namespace_level (tree, bool is_friend = false);
 extern bool push_class_level_binding (tree, tree);
 extern tree get_local_decls ();
 extern int function_parm_depth (void);
@@ -371,7 +371,7 @@ extern tree pushdecl (tree, bool is_friend = false);
 extern tree pushdecl_outermost_localscope (tree);
 extern tree pushdecl_top_level (tree, bool is_friend = false);
 extern tree pushdecl_top_level_and_finish (tree, tree);
-extern tree pushtag (tree, tree, tag_scope);
+extern tree pushtag (tree, tree, tag_scope = ts_current);
 extern int push_namespace (tree, bool make_inline = false);
 extern void pop_namespace (void);
 extern void push_nested_namespace (tree);
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 62e8509..6f8dbc3 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -5669,7 +5669,7 @@ template_parm_outer_level (tree t, void *data)
    If IS_FRIEND is true, DECL is a friend declaration.  */
 
 tree
-push_template_decl_real (tree decl, bool is_friend)
+push_template_decl (tree decl, bool is_friend)
 {
   tree tmpl;
   tree args;
@@ -5694,8 +5694,10 @@ push_template_decl_real (tree decl, bool is_friend)
 		    && DECL_TEMPLATE_SPECIALIZATION (decl)
 		    && TINFO_USED_TEMPLATE_ID (DECL_TEMPLATE_INFO (decl))));
 
-  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
-    is_friend = true;
+  /* No surprising friend functions.  */
+  gcc_checking_assert (is_friend
+		       || !(TREE_CODE (decl) == FUNCTION_DECL
+			    && DECL_FRIEND_P (decl)));
 
   if (is_friend)
     /* For a friend, we want the context of the friend, not
@@ -6096,12 +6098,6 @@ push_template_decl_real (tree decl, bool is_friend)
   return DECL_TEMPLATE_RESULT (tmpl);
 }
 
-tree
-push_template_decl (tree decl)
-{
-  return push_template_decl_real (decl, false);
-}
-
 /* FN is an inheriting constructor that inherits from the constructor
    template INHERITED; turn FN into a constructor template with a matching
    template header.  */
@@ -9943,7 +9939,7 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
 
 	  /* A local class.  Make sure the decl gets registered properly.  */
 	  if (context == current_function_decl)
-	    if (pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current)
+	    if (pushtag (DECL_NAME (gen_tmpl), t)
 		== error_mark_node)
 	      return error_mark_node;
 
@@ -11897,7 +11893,7 @@ instantiate_class_template_1 (tree type)
 		     tsubst_enum.  */
 		  if (name)
 		    SET_IDENTIFIER_TYPE_VALUE (name, newtag);
-		  pushtag (name, newtag, /*tag_scope=*/ts_current);
+		  pushtag (name, newtag);
 		}
 	    }
 	  else if (DECL_DECLARES_FUNCTION_P (t))
@@ -12077,6 +12073,7 @@ instantiate_class_template_1 (tree type)
 		/* friend class C<T>;  */
 		friend_type = tsubst (friend_type, args,
 				      tf_warning_or_error, NULL_TREE);
+	      
 	      /* Otherwise it's
 
 		   friend class C;
diff --git a/gcc/cp/ptree.c b/gcc/cp/ptree.c
index 11833e3..a28b722 100644
--- a/gcc/cp/ptree.c
+++ b/gcc/cp/ptree.c
@@ -332,8 +332,12 @@ debug_overload (tree node)
       tree decl = *iter;
       auto xloc = expand_location (DECL_SOURCE_LOCATION (decl));
       auto fullname = decl_as_string (decl, 0);
+      bool using_p = iter.using_p ();
+      bool hidden_p = iter.hidden_p ();
 
-      fprintf (file, "%p: %s:%d:%d \"%s\"\n", (void *)decl,
+      fprintf (file, "%p:%c%c %s:%d:%d \"%s\"\n", (void *)decl,
+	       hidden_p ? 'H' : '-',
+	       using_p ? 'U' : '-',
 	       xloc.file, xloc.line, xloc.column, fullname);
     }
 }
diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c
index 0ab3c42..7c4bff7 100644
--- a/gcc/cp/rtti.c
+++ b/gcc/cp/rtti.c
@@ -169,8 +169,7 @@ init_rtti_processing (void)
   tree type_info_type;
 
   push_nested_namespace (std_node);
-  type_info_type = xref_tag (class_type, get_identifier ("type_info"),
-			     /*tag_scope=*/ts_current, false);
+  type_info_type = xref_tag (class_type, get_identifier ("type_info"));
   pop_nested_namespace (std_node);
   const_type_info_type_node
     = cp_build_qualified_type (type_info_type, TYPE_QUAL_CONST);
@@ -761,9 +760,7 @@ build_dynamic_cast_1 (location_t loc, tree type, tree expr,
 
 	      push_abi_namespace ();
 	      tinfo_ptr = xref_tag (class_type,
-				    get_identifier ("__class_type_info"),
-				    /*tag_scope=*/ts_current, false);
-
+				    get_identifier ("__class_type_info"));
 	      tinfo_ptr = build_pointer_type
 		(cp_build_qualified_type
 		 (tinfo_ptr, TYPE_QUAL_CONST));
@@ -948,10 +945,8 @@ tinfo_base_init (tinfo_s *ti, tree target)
   vtable_ptr = ti->vtable;
   if (!vtable_ptr)
     {
-      tree real_type;
       push_abi_namespace ();
-      real_type = xref_tag (class_type, ti->name,
-			    /*tag_scope=*/ts_current, false);
+      tree real_type = xref_tag (class_type, ti->name);
       pop_abi_namespace ();
 
       if (!COMPLETE_TYPE_P (real_type))
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 11996c9..b093044 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3216,13 +3216,13 @@ begin_class_definition (tree t)
   if (t == error_mark_node || ! MAYBE_CLASS_TYPE_P (t))
     {
       t = make_class_type (RECORD_TYPE);
-      pushtag (make_anon_name (), t, /*tag_scope=*/ts_current);
+      pushtag (make_anon_name (), t);
     }
 
   if (TYPE_BEING_DEFINED (t))
     {
       t = make_class_type (TREE_CODE (t));
-      pushtag (TYPE_IDENTIFIER (t), t, /*tag_scope=*/ts_current);
+      pushtag (TYPE_IDENTIFIER (t), t);
     }
   maybe_process_partial_specialization (t);
   pushclass (t);
diff --git a/gcc/objcp/objcp-decl.c b/gcc/objcp/objcp-decl.c
index 9ae7f23..087b5d5 100644
--- a/gcc/objcp/objcp-decl.c
+++ b/gcc/objcp/objcp-decl.c
@@ -41,7 +41,7 @@ objcp_start_struct (location_t loc ATTRIBUTE_UNUSED,
   if (!name)
     name = make_anon_name ();
 
-  s = xref_tag (record_type, name, ts_global, 0);
+  s = xref_tag (record_type, name, ts_global);
   CLASSTYPE_DECLARED_CLASS (s) = 0;  /* this is a 'struct', not a 'class'.  */
   xref_basetypes (s, NULL_TREE);     /* no base classes here!  */
 
@@ -84,7 +84,7 @@ objcp_finish_function (void)
 tree
 objcp_xref_tag (enum tree_code code ATTRIBUTE_UNUSED, tree name)
 {
-  return xref_tag (record_type, name, ts_global, false);
+  return xref_tag (record_type, name, ts_global);
 }
 
 int