re PR c++/7874 (g++ finds friend functions defined in class-definition but not declared in the enclosing namespace)

./	PR g++/7874
	* c.opt (ffriend-injection): New C++ option.
	* doc/invoke.texi (Option Summary): Mention -ffriend-injection.
	(C++ Dialect Options): Document -ffriend-injection.
cp/
	PR g++/7874
	* cp-tree.h (struct lang_decl_flags): Add hidden_friend_p
	bitfield.  Make dummy bitfield one bit smaller.
	(DECL_HIDDEN_FRIEND_P): Define.
	(pushdecl_maybe_friend): Declare.
	(pushdecl_top_level_maybe_friend): Declare.
	* decl.c (duplicate_decls): Add newdecl_is_friend parameter.
	Change prototype and all callers.  Add assertion that a
	DECL_ARTIFICIAL FUNCTION_DECL is not DECL_HIDDEN_FRIEND_P.  Set
	DECL_ANTICIPATED and DECL_HIDDEN_FRIEND_P in duplicated decl if
	appropriate.
	* name-lookup.c (supplement_binding): Don't ignore a
	DECL_HIDDEN_FRIEND_P.
	(pushdecl_maybe_friend): Break out contents of pushdecl.  Add
	is_friend parameter.  Set DECL_ANTICIPATED and
	DECL_HIDDEN_FRIEND_P for a friend function.
	(pushdecl): Just call pushdecl_maybe_friend.
	(pushdecl_with_scope): Add is_friend parameter.  Change prototype
	and all callers.
	(pushdecl_namespace_level): Likewise.
	(push_overloaded_decl): Likewise.  Check DECL_HIDDEN_FRIEND_P as
	well as DECL_ANTICIPATED when checking for a builtin.
	(do_nonmember_using_decl): Check DECL_HIDDEN_FRIEND_P as well as
	DECL_ANTICIPATED when checking for a builtin.
	(do_nonmember_using_decl): Likewise.
	(pushdecl_top_level_1): Add is_friend parameter.  Change all
	callers.
	(pushdecl_top_level_maybe_friend): New function.
	(remove_hidden_names): New function.
	(struct arg_lookup): Add args field.
	(friend_of_associated_class_p): New static function.
	(arg_assoc_namespace): Ignore hidden functions which are not
	friends of an associated class of some argument.
	(lookup_arg_dependent): Remove hidden functions from list passed
	in.  Initialize k.args.
	* name-lookup.h (remove_hidden_names): Declare.
	* friend.c (do_friend): Call pushdecl_maybe_friend instead of
	pushdecl.
	* call.c (add_function_candidate): Change DECL_ANTICIPATED test to
	an assertion, with a check for DECL_HIDDEN_FRIEND_P.
	(build_new_function_call): Add koenig_p parameter.  Change
	prototype and callers.
	* pt.c (register_specialization): Add is_friend parameter.  Change
	all callers.
	(push_template_decl_real): Change is_friend parameter to bool.
	Change prototype and all callers.
	(tsubst_friend_class): Call pushdecl_top_level_maybe_friend
	instead of pushdecl_top_level.
testsuite/
	PR g++/7874
	* g++.dg/lookup/friend7.C: New test.
	* g++.dg/lookup/friend8.C: New test.
	* g++.dg/parse/defarg4.C: Add a parameter to the friend function,
	so that it will be found via argument dependent lookup.
	* g++.old-deja/g++.brendan/crash56.C: Don't expect errors for
	friend functions which will no longer be found.
	* g++.old-deja/g++.jason/friend.C: Add a parameter to the friend
	function g, so that it will be found via argument dependent
	lookup.
	* g++.old-deja/g++.jason/scoping15.C: Use -ffriend-injection.
	* g++.old-deja/g++.mike/net43.C: Likewise.

From-SVN: r104188

1 files changed, 15 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7dfa3a4..55cf558 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -171,7 +171,7 @@ in the following sections.
 @item C++ Language Options
 @xref{C++ Dialect Options,,Options Controlling C++ Dialect}.
 @gccoptlist{-fabi-version=@var{n}  -fno-access-control  -fcheck-new @gol
--fconserve-space  -fno-const-strings @gol
+-fconserve-space  -ffriend-injection  -fno-const-strings @gol
 -fno-elide-constructors @gol
 -fno-enforce-eh-specs @gol
 -ffor-scope  -fno-for-scope  -fno-gnu-keywords @gol
@@ -1425,6 +1425,20 @@ two definitions were merged.
 This option is no longer useful on most targets, now that support has
 been added for putting variables into BSS without making them common.
 
+@item -ffriend-injection
+@opindex ffriend-injection
+Inject friend functions into the enclosing namespace, so that they are
+visible outside the scope of the class in which they are declared.
+Friend functions were documented to work this way in the old Annotated
+C++ Reference Manual, and versions of G++ before 4.1 always worked
+that way.  However, in ISO C++ a friend function which is not declared
+in an enclosing scope can only be found using argument dependent
+lookup.  This option causes friends to be injected as they were in
+earlier releases.
+
+This option is for compatibility, and may be removed in a future
+release of G++.
+
 @item -fno-const-strings
 @opindex fno-const-strings
 Give string constants type @code{char *} instead of type @code{const