Index: gcc/testsuite/g++.dg/template/operator7.C
===================================================================
--- gcc/testsuite/g++.dg/template/operator7.C	(revision 0)
+++ gcc/testsuite/g++.dg/template/operator7.C	(revision 0)
@@ -0,0 +1,6 @@
+//PR c++/27493
+
+template<operator T> void foo()         // { dg-error "before|template" }
+{
+  struct A {};
+}
Index: gcc/testsuite/g++.dg/template/operator8.C
===================================================================
--- gcc/testsuite/g++.dg/template/operator8.C	(revision 0)
+++ gcc/testsuite/g++.dg/template/operator8.C	(revision 0)
@@ -0,0 +1,12 @@
+//PR c++/27494
+
+struct A
+{
+    template<operator+> void foo() {}   // { dg-error "identifier|non-function|template arguments" }
+};
+ 
+struct B
+{
+    template<operator> void foo() {}    // { dg-error "identifier|non-function|'void'" }
+    template<int> void bar() {}         // { dg-error "template arguments" }
+};
Index: gcc/testsuite/g++.dg/template/operator9.C
===================================================================
--- gcc/testsuite/g++.dg/template/operator9.C	(revision 0)
+++ gcc/testsuite/g++.dg/template/operator9.C	(revision 0)
@@ -0,0 +1,9 @@
+//PR c++/27670
+
+template<operator+> void foo(); // { dg-error "before|non-function|template" }
+
+void bar()
+{
+  foo();                        // { dg-error "no matching function" }
+}
+ 
Index: gcc/testsuite/g++.dg/template/crash56.C
===================================================================
--- gcc/testsuite/g++.dg/template/crash56.C	(revision 0)
+++ gcc/testsuite/g++.dg/template/crash56.C	(revision 0)
@@ -0,0 +1,10 @@
+//PR c++/27397
+
+template<int(> struct A;        // { dg-error "token" }
+
+template<typename> struct B
+{
+    template<int(> struct C;    // { dg-error "token" }
+};
+
+A<char> a;                      // { dg-error "type/value mismatch|constant|declaration" }
Index: gcc/testsuite/g++.dg/template/typedef4.C
===================================================================
--- gcc/testsuite/g++.dg/template/typedef4.C	(revision 116592)
+++ gcc/testsuite/g++.dg/template/typedef4.C	(working copy)
@@ -1,7 +1,7 @@
 // PR c++/27572
 // { dg-do compile }
 
-template<typedef> void foo();  // { dg-error "no type|typedef declaration" }
+template<typedef> void foo();  // { dg-error "no type|typedef declaration|template" }
 
 void bar()
 {
Index: gcc/testsuite/g++.dg/template/typedef5.C
===================================================================
--- gcc/testsuite/g++.dg/template/typedef5.C	(revision 116592)
+++ gcc/testsuite/g++.dg/template/typedef5.C	(working copy)
@@ -1,7 +1,7 @@
 // PR c++/27572
 // { dg-do compile }
 
-template<typedef,int>        struct A1; // { dg-error "no type|typedef declaration" }
-template<typedef x,int>      struct A2; // { dg-error "no type|typedef declaration" }
-template<typedef x[],int>    struct A3; // { dg-error "no type|typedef declaration" }
-template<typedef int x, int> struct A4; // { dg-error "typedef declaration" }
+template<typedef,int>        struct A1; // { dg-error "no type|typedef declaration|default argument" }
+template<typedef x,int>      struct A2; // { dg-error "no type|typedef declaration|default argument" }
+template<typedef x[],int>    struct A3; // { dg-error "no type|typedef declaration|default argument" }
+template<typedef int x, int> struct A4; // { dg-error "typedef declaration|default argument" }
Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c	(revision 116592)
+++ gcc/cp/parser.c	(working copy)
@@ -8394,6 +8394,13 @@ cp_parser_template_parameter_list (cp_pa
 	parameter_list = process_template_parm (parameter_list,
 						parameter,
 						is_non_type);
+      else
+	{
+	  tree err_parm = build_tree_list (parameter, parameter);
+	  TREE_VALUE (err_parm) = error_mark_node;
+	  parameter_list = chainon (parameter_list, err_parm);
+	}
+
       /* Peek at the next token.  */
       token = cp_lexer_peek_token (parser->lexer);
       /* If it's not a `,', we're done.  */