From f7af3ad6372ccc17f9d3d43566298ac843adfd67 Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Mon, 5 Mar 2018 18:44:24 +0000
Subject: [PATCH] [PR c++/84702] ICE with default tmpl arg of overload set

https://gcc.gnu.org/ml/gcc-patches/2018-03/msg00227.html
	PR c++/84702
	* pt.c (process_template_arg): Mark lookup_keep on a default arg.

	PR c++/84702
	* g++.dg/lookup/pr84702.C: New.

From-SVN: r258258
---
 gcc/cp/ChangeLog                      |  5 +++++
 gcc/cp/pt.c                           |  3 +++
 gcc/testsuite/ChangeLog               |  5 +++++
 gcc/testsuite/g++.dg/lookup/pr84702.C | 13 +++++++++++++
 4 files changed, 26 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/lookup/pr84702.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 001cb6a559a..3218814124e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-05  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84702
+	* pt.c (process_template_arg): Mark lookup_keep on a default arg.
+
 2018-03-05  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/84707
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index c81bd5094d9..89024c10fe2 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -4425,6 +4425,9 @@ process_template_parm (tree list, location_t parm_loc, tree parm,
 
   pushdecl (decl);
 
+  if (defval && TREE_CODE (defval) == OVERLOAD)
+    lookup_keep (defval, true);
+  
   /* Build the parameter node linking the parameter declaration,
      its default argument (if any), and its constraints (if any). */
   parm = build_tree_list (defval, parm);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e80a72802ee..9f9afb0df12 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-05  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84702
+	* g++.dg/lookup/pr84702.C: New.
+
 2018-03-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/84564
diff --git a/gcc/testsuite/g++.dg/lookup/pr84702.C b/gcc/testsuite/g++.dg/lookup/pr84702.C
new file mode 100644
index 00000000000..6b9e1b4e780
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/pr84702.C
@@ -0,0 +1,13 @@
+// PR c++/84702 failure to mark overload to keep
+// { dg-do compile { target c++11 } }
+
+void a ();
+
+namespace {
+  void a (int);
+}
+
+template<void (&b)() = a>
+void c () {
+  c ();
+}
-- 
2.30.2