c++: DECL_FRIEND_P cleanup

DECL_FRIEND_P's meaning has changed over time.  It now (almost) means
the the friend function decl has not been met via an explicit decl.
This completes that transition, renaming it to DECL_UNIQUE_FRIEND_P,
so one doesn't think it is the sole indicator of friendliness (plenty
of friends do not have the flag set).  This allows reduction in the
complexity of managing the field -- all in duplicate_decls now.

	gcc/cp/
	* cp-tree.h (struct lang_decl_fn): Adjust context comment.
	(DECL_FRIEND_P): Replace with ...
	(DECL_UNIQUE_FRIEND_P): ... this.  Only for FUNCTION_DECLs.
	(DECL_FRIEND_CONTEXT): Adjust.
	* class.c (add_implicitly_declared_members): Detect friendly
	spaceship from context.
	* constraint.cc (remove_constraints): Use a checking assert.
	(maybe_substitute_reqs_for): Use DECL_UNIQUE_FRIEND_P.
	* decl.c (check_no_redeclaration_friend_default_args):
	DECL_UNIQUE_FRIEND_P is signficant, not hiddenness.
	(duplicate_decls): Adjust DECL_UNIQUE_FRIEND_P clearing.
	(redeclaration_error_message): Use DECL_UNIQUE_FRIEND_P.
	(start_preparsed_function): Correct in-class friend processing.
	Refactor some initializers.
	(grokmethod): Directly check friend decl-spec.
	* decl2.c (grokfield): Check DECL_UNIQUE_FRIEND_P.
	* friend.c (do_friend): Set DECL_UNIQUE_FRIEND_P first, remove
	extraneous conditions.  Don't re set it afterwards.
	* name-lookup.c (lookup_elaborated_type_1): Simplify revealing
	code.
	(do_pushtag): Likewise.
	* pt.c (optimize_specialization_lookup_p): Check
	DECL_UNIQUE_FRIEND_P.
	(push_template_decl): Likewise.  Drop unneeded friend setting.
	(type_dependent_expression_p): Check DECL_UNIQUE_FRIEND_P.
	libcc1/
	* libcp1plugin.cc (plugin_add_friend): Set DECL_UNIQUE_FRIEND_P.

1 files changed, 4 insertions, 8 deletions

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 555dc47..503c0e7 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -1181,7 +1181,7 @@ optimize_specialization_lookup_p (tree tmpl)
 	     not have template information.  The optimized lookup relies
 	     on having ARGS be the template arguments for both the class
 	     and the function template.  */
-	  && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
+	  && !DECL_UNIQUE_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
 }
 
 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
@@ -5701,7 +5701,7 @@ push_template_decl (tree decl, bool is_friend)
   /* No surprising friend functions.  */
   gcc_checking_assert (is_friend
 		       || !(TREE_CODE (decl) == FUNCTION_DECL
-			    && DECL_FRIEND_P (decl)));
+			    && DECL_UNIQUE_FRIEND_P (decl)));
 
   if (is_friend)
     /* For a friend, we want the context of the friend, not
@@ -6022,10 +6022,6 @@ push_template_decl (tree decl, bool is_friend)
       if (!ctx
 	  && !(is_friend && template_class_depth (current_class_type) > 0))
 	{
-	  /* Hide template friend classes that haven't been declared yet.  */
-	  if (is_friend && TREE_CODE (decl) == TYPE_DECL)
-	    DECL_FRIEND_P (tmpl) = 1;
-
 	  tmpl = pushdecl_namespace_level (tmpl, /*hiding=*/is_friend);
 	  if (tmpl == error_mark_node)
 	    return error_mark_node;
@@ -13960,7 +13956,7 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
     if (!lambda_fntype)
       set_constraints (r, ci);
 
-  if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
+  if (DECL_FRIEND_CONTEXT (t))
     SET_DECL_FRIEND_CONTEXT (r,
 			     tsubst (DECL_FRIEND_CONTEXT (t),
 				     args, complain, in_decl));
@@ -27049,7 +27045,7 @@ type_dependent_expression_p (tree expression)
       && !(DECL_CLASS_SCOPE_P (expression)
 	   && dependent_type_p (DECL_CONTEXT (expression)))
       && !(DECL_LANG_SPECIFIC (expression)
-	   && DECL_FRIEND_P (expression)
+	   && DECL_UNIQUE_FRIEND_P (expression)
 	   && (!DECL_FRIEND_CONTEXT (expression)
 	       || dependent_type_p (DECL_FRIEND_CONTEXT (expression))))
       && !DECL_LOCAL_DECL_P (expression))