From 1e9afbb0f38db696b0c3cdec7aea17dcb966b7f2 Mon Sep 17 00:00:00 2001
From: paolo <paolo@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 19 Apr 2019 15:36:20 +0000
Subject: [PATCH] /cp 2019-04-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/89900
	* pt.c (fn_type_unification): When handling null explicit
	arguments do not special case non-parameter packs.

/testsuite
2019-04-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/89900
	* g++.dg/cpp0x/pr89900-1.C: New.
	* g++.dg/cpp0x/pr89900-2.C: Likewise.
	* g++.dg/cpp0x/pr89900-3.C: Likewise.
	* g++.dg/cpp0x/pr89900-4.C: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@270459 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                       |  6 ++++++
 gcc/cp/pt.c                            | 14 +++++---------
 gcc/testsuite/ChangeLog                |  8 ++++++++
 gcc/testsuite/g++.dg/cpp0x/pr89900-1.C | 10 ++++++++++
 gcc/testsuite/g++.dg/cpp0x/pr89900-2.C | 10 ++++++++++
 gcc/testsuite/g++.dg/cpp0x/pr89900-3.C | 10 ++++++++++
 gcc/testsuite/g++.dg/cpp0x/pr89900-4.C | 10 ++++++++++
 7 files changed, 59 insertions(+), 9 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr89900-1.C
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr89900-2.C
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr89900-3.C
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr89900-4.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index db9a3a8d4be4..8eb2953e051e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2019-04-19  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/89900
+	* pt.c (fn_type_unification): When handling null explicit
+	arguments do not special case non-parameter packs.
+
 2019-04-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/90138
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 842dacf95431..6d4140fb018e 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -20179,21 +20179,17 @@ fn_type_unification (tree fn,
               parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
             }
 
-	  if (!parameter_pack && targ == NULL_TREE)
+	  if (targ == NULL_TREE)
 	    /* No explicit argument for this template parameter.  */
 	    incomplete = true;
-
-          if (parameter_pack && pack_deducible_p (parm, fn))
+	  else if (parameter_pack && pack_deducible_p (parm, fn))
             {
               /* Mark the argument pack as "incomplete". We could
                  still deduce more arguments during unification.
 	         We remove this mark in type_unification_real.  */
-              if (targ)
-                {
-                  ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
-                  ARGUMENT_PACK_EXPLICIT_ARGS (targ) 
-                    = ARGUMENT_PACK_ARGS (targ);
-                }
+	      ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
+	      ARGUMENT_PACK_EXPLICIT_ARGS (targ)
+		= ARGUMENT_PACK_ARGS (targ);
 
               /* We have some incomplete argument packs.  */
               incomplete = true;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7458b4cc2ef9..653c20113c64 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2019-04-19  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/89900
+	* g++.dg/cpp0x/pr89900-1.C: New.
+	* g++.dg/cpp0x/pr89900-2.C: Likewise.
+	* g++.dg/cpp0x/pr89900-3.C: Likewise.
+	* g++.dg/cpp0x/pr89900-4.C: Likewise.
+
 2019-04-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/90139
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr89900-1.C b/gcc/testsuite/g++.dg/cpp0x/pr89900-1.C
new file mode 100644
index 000000000000..e92cd1fbb1ad
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr89900-1.C
@@ -0,0 +1,10 @@
+// { dg-do compile { target c++11 } }
+
+template<typename SX, typename ...XE> void
+fk (XE..., SW);  // { dg-error "12:.SW. has not been declared" }
+
+void
+w9 (void)
+{
+  fk<int> (0);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr89900-2.C b/gcc/testsuite/g++.dg/cpp0x/pr89900-2.C
new file mode 100644
index 000000000000..a70349dd6e73
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr89900-2.C
@@ -0,0 +1,10 @@
+// { dg-do compile { target c++11 } }
+
+template<typename SX, typename ...XE> void
+fk (XE..., int);
+
+void
+w9 (void)
+{
+  fk<int> (0);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr89900-3.C b/gcc/testsuite/g++.dg/cpp0x/pr89900-3.C
new file mode 100644
index 000000000000..178d8f13d869
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr89900-3.C
@@ -0,0 +1,10 @@
+// { dg-do compile { target c++11 } }
+
+template<typename ...XE> void
+fk (XE..., SW);  // { dg-error "12:.SW. has not been declared" }
+
+void
+w9 (void)
+{
+  fk (0);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr89900-4.C b/gcc/testsuite/g++.dg/cpp0x/pr89900-4.C
new file mode 100644
index 000000000000..0d375dabaf52
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr89900-4.C
@@ -0,0 +1,10 @@
+// { dg-do compile { target c++11 } }
+
+template<typename ...XE> void
+fk (XE..., int);
+
+void
+w9 (void)
+{
+  fk (0);
+}
-- 
2.39.2