From 199b7a3586061f951fa737656217206164456910 Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov@gmail.com>
Date: Thu, 15 Jan 2015 21:02:15 +0000
Subject: [PATCH] re PR c++/59366 (A friend function template defined in a
 class is found without ADL)

	PR c++/59366
	* name-lookup.c (pushdecl_maybe_friend_1): Hide friend functions
	and function templates, declared only in the class.
	* decl.c (duplicate_decls): Reveal hidden friend functions or
	function templates, if they are redeclared outside the class.

From-SVN: r219689
---
 gcc/cp/ChangeLog                            |  8 +++++++
 gcc/cp/decl.c                               | 17 +++++++++++----
 gcc/cp/name-lookup.c                        | 23 +++++++++++----------
 gcc/testsuite/g++.dg/template/friend57.C    | 21 +++++++++++++++++++
 gcc/testsuite/g++.old-deja/g++.pt/friend5.C |  2 +-
 5 files changed, 55 insertions(+), 16 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/friend57.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 2e74c0a4068..9120e07eaf9 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2015-01-15  Momchil Velikov  <momchil.velikov@gmail.com>
+
+	PR c++/59366
+	* name-lookup.c (pushdecl_maybe_friend_1): Hide friend functions
+	and function templates, declared only in the class.
+	* decl.c (duplicate_decls): Reveal hidden friend functions or
+	function templates, if they are redeclared outside the class.
+
 2015-01-15  Jason Merrill  <jason@redhat.com>
 
 	PR c++/64356
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 9d9a04eeee6..35f483363d8 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -1871,6 +1871,19 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
   DECL_ATTRIBUTES (newdecl)
     = (*targetm.merge_decl_attributes) (olddecl, newdecl);
 
+  if (DECL_DECLARES_FUNCTION_P (olddecl) && DECL_DECLARES_FUNCTION_P (newdecl))
+    {
+      olddecl_friend = DECL_FRIEND_P (olddecl);
+      hidden_friend = (DECL_ANTICIPATED (olddecl)
+		       && DECL_HIDDEN_FRIEND_P (olddecl)
+		       && newdecl_is_friend);
+      if (!hidden_friend)
+	{
+	  DECL_ANTICIPATED (olddecl) = 0;
+	  DECL_HIDDEN_FRIEND_P (olddecl) = 0;
+	}
+    }
+
   if (TREE_CODE (newdecl) == TEMPLATE_DECL)
     {
       tree old_result;
@@ -2153,10 +2166,6 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
       if (DECL_DECLARES_FUNCTION_P (newdecl))
 	{
 	  DECL_NONCONVERTING_P (newdecl) = DECL_NONCONVERTING_P (olddecl);
-	  olddecl_friend = DECL_FRIEND_P (olddecl);
-	  hidden_friend = (DECL_ANTICIPATED (olddecl)
-			   && DECL_HIDDEN_FRIEND_P (olddecl)
-			   && newdecl_is_friend);
 	  DECL_BEFRIENDING_CLASSES (newdecl)
 	    = chainon (DECL_BEFRIENDING_CLASSES (newdecl),
 		       DECL_BEFRIENDING_CLASSES (olddecl));
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index cf612407e9e..ba16befa74d 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -933,7 +933,18 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
 	}
 
       if (DECL_DECLARES_FUNCTION_P (t))
-	check_default_args (t);
+	{
+	  check_default_args (t);
+
+	  if (is_friend && t == x && !flag_friend_injection)
+	    {
+	      /* This is a new friend declaration of a function or a
+		 function template, so hide it from ordinary function
+		 lookup.  */
+	      DECL_ANTICIPATED (t) = 1;
+	      DECL_HIDDEN_FRIEND_P (t) = 1;
+	    }
+	}
 
       if (t != x || DECL_FUNCTION_TEMPLATE_P (t))
 	return t;
@@ -995,16 +1006,6 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
 	    }
 	}
 
-      if (TREE_CODE (x) == FUNCTION_DECL
-	  && is_friend
-	  && !flag_friend_injection)
-	{
-	  /* This is a new declaration of a friend function, so hide
-	     it from ordinary function lookup.  */
-	  DECL_ANTICIPATED (x) = 1;
-	  DECL_HIDDEN_FRIEND_P (x) = 1;
-	}
-
       /* This name is new in its binding level.
 	 Install the new declaration and return it.  */
       if (namespace_bindings_p ())
diff --git a/gcc/testsuite/g++.dg/template/friend57.C b/gcc/testsuite/g++.dg/template/friend57.C
new file mode 100644
index 00000000000..7077d5e53cb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/friend57.C
@@ -0,0 +1,21 @@
+// PR c++/59366
+// { dg-do compile }
+template<typename T> void f(T);
+
+struct S
+{
+  template<typename T> friend void f(T) {}
+  template<typename T> friend void g(T) {}
+  template<typename T> friend void h(T) {}
+};
+
+template<typename T> void h(T);
+
+int
+main ()
+{
+  f(1);
+  g(1); // { dg-error "'g' was not declared in this scope" }
+  g(S());
+  h(1);
+}
diff --git a/gcc/testsuite/g++.old-deja/g++.pt/friend5.C b/gcc/testsuite/g++.old-deja/g++.pt/friend5.C
index 3feeb684e36..edb9d623359 100644
--- a/gcc/testsuite/g++.old-deja/g++.pt/friend5.C
+++ b/gcc/testsuite/g++.old-deja/g++.pt/friend5.C
@@ -14,5 +14,5 @@ class C
 
 int main()
 {
-  f(7);
+  f(C());
 }
-- 
2.30.2