re PR c++/89900 (ICE: Segmentation fault (in check_instantiated_arg))

/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.

From-SVN: r270459

gcc/cp/ChangeLog

+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

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;

gcc/testsuite/ChangeLog

+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

gcc/testsuite/g++.dg/cpp0x/pr89900-1.C

+// { 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);
+}

gcc/testsuite/g++.dg/cpp0x/pr89900-2.C

+// { dg-do compile { target c++11 } }
+
+template<typename SX, typename ...XE> void
+fk (XE..., int);
+
+void
+w9 (void)
+{
+  fk<int> (0);
+}

gcc/testsuite/g++.dg/cpp0x/pr89900-3.C

+// { 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);
+}

gcc/testsuite/g++.dg/cpp0x/pr89900-4.C

+// { dg-do compile { target c++11 } }
+
+template<typename ...XE> void
+fk (XE..., int);
+
+void
+w9 (void)
+{
+  fk (0);
+}