Index: cp/pt.c
===================================================================
--- cp/pt.c	(revision 276015)
+++ cp/pt.c	(working copy)
@@ -2808,8 +2808,9 @@ check_explicit_specialization (tree declarator,
 	      /* This case handles bogus declarations like template <>
 		 template <class T> void f<int>(); */
 
-	      error ("template-id %qD in declaration of primary template",
-		     declarator);
+	      error_at (cp_expr_loc_or_input_loc (declarator),
+			"template-id %qE in declaration of primary template",
+			declarator);
 	      return decl;
 	    }
 	}
@@ -2867,8 +2868,9 @@ check_explicit_specialization (tree declarator,
 	     template <class T> void f<int>(); */
 
 	  if (!uses_template_parms (TREE_OPERAND (declarator, 1)))
-	    error ("template-id %qD in declaration of primary template",
-		   declarator);
+	    error_at (cp_expr_loc_or_input_loc (declarator),
+		      "template-id %qE in declaration of primary template",
+		      declarator);
 	  else if (variable_template_p (TREE_OPERAND (declarator, 0)))
 	    {
 	      /* Partial specialization of variable template.  */
@@ -2877,11 +2879,13 @@ check_explicit_specialization (tree declarator,
 	      goto ok;
 	    }
 	  else if (cxx_dialect < cxx14)
-	    error ("non-type partial specialization %qD "
-		   "is not allowed", declarator);
+	    error_at (cp_expr_loc_or_input_loc (declarator),
+		      "non-type partial specialization %qE "
+		      "is not allowed", declarator);
 	  else
-	    error ("non-class, non-variable partial specialization %qD "
-		   "is not allowed", declarator);
+	    error_at (cp_expr_loc_or_input_loc (declarator),
+		      "non-class, non-variable partial specialization %qE "
+		      "is not allowed", declarator);
 	  return decl;
 	ok:;
 	}
@@ -4958,8 +4962,9 @@ process_partial_specialization (tree decl)
             {
               if ((!packed_args && tpd.arg_uses_template_parms[i])
                   || (packed_args && uses_template_parms (arg)))
-                error ("template argument %qE involves template parameter(s)",
-                       arg);
+		error_at (cp_expr_loc_or_input_loc (arg),
+			  "template argument %qE involves template "
+			  "parameter(s)", arg);
               else 
                 {
                   /* Look at the corresponding template parameter,
@@ -6258,13 +6263,14 @@ convert_nontype_argument_function (tree type, tree
     {
       if (complain & tf_error)
 	{
-	  error ("%qE is not a valid template argument for type %qT",
-		 expr, type);
+	  location_t loc = cp_expr_loc_or_input_loc (expr);
+	  error_at (loc, "%qE is not a valid template argument for type %qT",
+		    expr, type);
 	  if (TYPE_PTR_P (type))
-	    inform (input_location, "it must be the address of a function "
+	    inform (loc, "it must be the address of a function "
 		    "with external linkage");
 	  else
-	    inform (input_location, "it must be the name of a function with "
+	    inform (loc, "it must be the name of a function with "
 		    "external linkage");
 	}
       return NULL_TREE;
@@ -6275,14 +6281,15 @@ convert_nontype_argument_function (tree type, tree
     {
       if (complain & tf_error)
 	{
+	  location_t loc = cp_expr_loc_or_input_loc (expr);
 	  if (cxx_dialect >= cxx11)
-	    error ("%qE is not a valid template argument for type %qT "
-		   "because %qD has no linkage",
-		   expr, type, fn_no_ptr);
+	    error_at (loc, "%qE is not a valid template argument for type "
+		      "%qT because %qD has no linkage",
+		      expr, type, fn_no_ptr);
 	  else
-	    error ("%qE is not a valid template argument for type %qT "
-		   "because %qD does not have external linkage",
-		   expr, type, fn_no_ptr);
+	    error_at (loc, "%qE is not a valid template argument for type "
+		      "%qT because %qD does not have external linkage",
+		      expr, type, fn_no_ptr);
 	}
       return NULL_TREE;
     }
@@ -6309,7 +6316,6 @@ static bool
 check_valid_ptrmem_cst_expr (tree type, tree expr,
 			     tsubst_flags_t complain)
 {
-  location_t loc = cp_expr_loc_or_input_loc (expr);
   tree orig_expr = expr;
   STRIP_NOPS (expr);
   if (null_ptr_cst_p (expr))
@@ -6326,6 +6332,7 @@ check_valid_ptrmem_cst_expr (tree type, tree expr,
     return true;
   if (complain & tf_error)
     {
+      location_t loc = cp_expr_loc_or_input_loc (orig_expr);
       error_at (loc, "%qE is not a valid template argument for type %qT",
 		orig_expr, type);
       if (TREE_CODE (expr) != PTRMEM_CST)
@@ -6623,16 +6630,18 @@ invalid_tparm_referent_p (tree type, tree expr, ts
 	if (!VAR_P (decl))
 	  {
 	    if (complain & tf_error)
-	      error ("%qE is not a valid template argument of type %qT "
-		     "because %qE is not a variable", expr, type, decl);
+	      error_at (cp_expr_loc_or_input_loc (expr),
+			"%qE is not a valid template argument of type %qT "
+			"because %qE is not a variable", expr, type, decl);
 	    return true;
 	  }
 	else if (cxx_dialect < cxx11 && !DECL_EXTERNAL_LINKAGE_P (decl))
 	  {
 	    if (complain & tf_error)
-	      error ("%qE is not a valid template argument of type %qT "
-		     "in C++98 because %qD does not have external linkage",
-		     expr, type, decl);
+	      error_at (cp_expr_loc_or_input_loc (expr),
+			"%qE is not a valid template argument of type %qT "
+			"in C++98 because %qD does not have external linkage",
+			expr, type, decl);
 	    return true;
 	  }
 	else if ((cxx_dialect >= cxx11 && cxx_dialect < cxx17)
@@ -6639,8 +6648,9 @@ invalid_tparm_referent_p (tree type, tree expr, ts
 		 && decl_linkage (decl) == lk_none)
 	  {
 	    if (complain & tf_error)
-	      error ("%qE is not a valid template argument of type %qT "
-		     "because %qD has no linkage", expr, type, decl);
+	      error_at (cp_expr_loc_or_input_loc (expr),
+			"%qE is not a valid template argument of type %qT "
+			"because %qD has no linkage", expr, type, decl);
 	    return true;
 	  }
 	/* C++17: For a non-type template-parameter of reference or pointer
@@ -8129,8 +8139,9 @@ convert_template_argument (tree parm,
       if (val == NULL_TREE)
 	val = error_mark_node;
       else if (val == error_mark_node && (complain & tf_error))
-	error ("could not convert template argument %qE from %qT to %qT",
-	       orig_arg, TREE_TYPE (orig_arg), t);
+	error_at (cp_expr_loc_or_input_loc (orig_arg),
+		  "could not convert template argument %qE from %qT to %qT",
+		  orig_arg, TREE_TYPE (orig_arg), t);
 
       if (INDIRECT_REF_P (val))
         {
Index: testsuite/g++.dg/cpp0x/pr68724.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr68724.C	(revision 276015)
+++ testsuite/g++.dg/cpp0x/pr68724.C	(working copy)
@@ -9,7 +9,7 @@ struct integral_constant
 integral_constant<bool, true> inst;
 
 template <typename _Tp>
-struct integral_constant<bool, __is_enum(_Tp)> // { dg-error "" }
+struct integral_constant<bool, __is_enum(_Tp)> // { dg-error "32:template argument" }
 {
 };
 
Index: testsuite/g++.dg/cpp0x/variadic38.C
===================================================================
--- testsuite/g++.dg/cpp0x/variadic38.C	(revision 276015)
+++ testsuite/g++.dg/cpp0x/variadic38.C	(working copy)
@@ -3,4 +3,4 @@ template<int... Values>
 struct int_vec {};
 
 template<int... Values>
-struct int_vec<0, (Values+1)...> {}; // { dg-error "involves template parameter" }
+struct int_vec<0, (Values+1)...> {}; // { dg-error "26:template argument" }
Index: testsuite/g++.dg/cpp1z/nontype2.C
===================================================================
--- testsuite/g++.dg/cpp1z/nontype2.C	(revision 276015)
+++ testsuite/g++.dg/cpp1z/nontype2.C	(working copy)
@@ -8,7 +8,7 @@ template<int* p> class X { };
 template<const char *s> class Y {};
 template<const std::type_info &> class Z {};
 
-X<&s.m> x7;			// { dg-error "" }
+X<&s.m> x7;			// { dg-error "3:.& s.S::m. is not a valid template argument" }
 Y<"foo"> y1;			// { dg-error "string literal" }
 Z<typeid(p)> z1;		// { dg-error "" }
 
Index: testsuite/g++.dg/parse/explicit1.C
===================================================================
--- testsuite/g++.dg/parse/explicit1.C	(revision 276015)
+++ testsuite/g++.dg/parse/explicit1.C	(working copy)
@@ -7,5 +7,5 @@
 
 struct foo { 
         template<typename T> void bar (T &t) {}
-        template<> void bar<double>(double &t) {} // { dg-error "non-namespace|template|function" }
+        template<> void bar<double>(double &t) {} // { dg-error "25:template-id .bar<double>. in declaration|explicit specialization" }
 };
Index: testsuite/g++.dg/template/crash11.C
===================================================================
--- testsuite/g++.dg/template/crash11.C	(revision 276015)
+++ testsuite/g++.dg/template/crash11.C	(working copy)
@@ -6,4 +6,6 @@
 // substitution.
 
 template <class T, class U> void foo(T, U) {}
-template <class T> void foo<T,void>(T, void) {} // { dg-error "incomplete|invalid|partial" }
+template <class T> void foo<T,void>(T, void) {} // { dg-error "40:invalid use of type .void." }
+// { dg-error "25:non-class, non-variable partial specialization" "" { target c++14 } .-1 }
+// { dg-error "25:non-type partial specialization" "" { target c++11_down } .-2 }
Index: testsuite/g++.dg/template/non-dependent8.C
===================================================================
--- testsuite/g++.dg/template/non-dependent8.C	(revision 276015)
+++ testsuite/g++.dg/template/non-dependent8.C	(working copy)
@@ -17,5 +17,6 @@ struct X
 template <class T>
 struct Foo
 {
-  X<&S::i> x;	// { dg-error "convert|no type" }
+  X<&S::i> x;	// { dg-error "5:could not convert" "" { target c++17 } }
+  // { dg-error "could not convert" "" { target c++14_down } .-1 }
 };
Index: testsuite/g++.dg/template/nontype-array1.C
===================================================================
--- testsuite/g++.dg/template/nontype-array1.C	(revision 276015)
+++ testsuite/g++.dg/template/nontype-array1.C	(working copy)
@@ -26,7 +26,7 @@ int main()
   Message<s2> m2;  // OK for clang since C++14, for gcc since C++17
   Message<s3> m3;  // OK for clang/gcc since C++11
 
-  A<f2()> a1; // { dg-error "" "" { target c++14_down } }
+  A<f2()> a1; // { dg-error "7:.f2\\(\\). is not a valid template argument" "" { target c++14_down } }
 
   static char const s4[] = "hi";
   static constexpr char const s5[] = "hi";  // OK since C++11
@@ -33,7 +33,7 @@ int main()
   Message<s4> m4;  // { dg-error "no linkage" "" { target c++14_down } }
   Message<s5> m5;  // { dg-error "no linkage" "" { target c++14_down } }
   Message<f()> m6; // { dg-error "" "" { target c++14_down } }
-  Message<B{}> m7; // { dg-error "" "" { target c++14_down } }
+  Message<B{}> m7; // { dg-error "11:could not convert template argument" "" { target c++14_down } }
 
 
   char const s8[] = "hi";
Index: testsuite/g++.dg/template/nontype3.C
===================================================================
--- testsuite/g++.dg/template/nontype3.C	(revision 276015)
+++ testsuite/g++.dg/template/nontype3.C	(working copy)
@@ -16,7 +16,7 @@ template <int *PI>
 void dep6(bar<PI+1> *); // { dg-error "" "integral or enumeration" }
 
 template <int I>
-void dep7(bar<I+1> *);		// { dg-error "" }
+void dep7(bar<I+1> *);		// { dg-error "16:could not convert template argument" }
 
 template <int *PI>
 void dep8(foo< *PI > *); // { dg-error "" "integral or enumeration" }
Index: testsuite/g++.dg/template/nontype8.C
===================================================================
--- testsuite/g++.dg/template/nontype8.C	(revision 276015)
+++ testsuite/g++.dg/template/nontype8.C	(working copy)
@@ -6,8 +6,10 @@ template<int* p> class X { };
 int a[10];
 struct S { int m; static int s; } s;
 
-X<&a[2]> x3;                    // { dg-error "" } address of array element
-X<&s.m> x4;                     // { dg-error "" } address of non-static member
+X<&a[2]> x3;                    // { dg-error "3:.& a\\\[2\\\]. is not a valid template argument" "" { target c++17 } }
+// { dg-error "" "" { target c++14_down } .-1 }
+X<&s.m> x4;                     // { dg-error "3:.& s.S::m. is not a valid template argument" "" { target c++17 } }
+// { dg-error "" "" { target c++14_down } .-1 }
 X<&s.s> x5;                     // { dg-error "" "" { target { ! c++17 } } } &S::s must be used
 X<&S::s> x6;                    // OK: address of static member
 
Index: testsuite/g++.dg/template/partial5.C
===================================================================
--- testsuite/g++.dg/template/partial5.C	(revision 276015)
+++ testsuite/g++.dg/template/partial5.C	(working copy)
@@ -21,4 +21,4 @@ template<typename T, T V>
 struct Z { };
 
 template<typename T>
-struct Z<T, (T)0> { }; // { dg-error "involves template parameter" }
+struct Z<T, (T)0> { }; // { dg-error "13:template argument" }
Index: testsuite/g++.dg/template/spec33.C
===================================================================
--- testsuite/g++.dg/template/spec33.C	(revision 276015)
+++ testsuite/g++.dg/template/spec33.C	(working copy)
@@ -3,5 +3,5 @@
 struct A
 {
     template<int> static void foo   () {}
-    template<>    static void foo<0>() {}  // { dg-error "explicit|template" }
+    template<>    static void foo<0>() {}  // { dg-error "31:template-id .foo<0>. in declaration|explicit specialization" }
 }; 
Index: testsuite/g++.old-deja/g++.pt/memtemp64.C
===================================================================
--- testsuite/g++.old-deja/g++.pt/memtemp64.C	(revision 276015)
+++ testsuite/g++.old-deja/g++.pt/memtemp64.C	(working copy)
@@ -10,7 +10,8 @@ template <class C>
 struct S2
 {
   template <class T>
-  void f<S1<T> >(T) {}  // { dg-error "" } bad specialization.
+  void f<S1<T> >(T) {}  // { dg-error "8:non-class, non-variable partial specialization" "" { target c++14 } }
+  // { dg-error "8:non-type partial specialization" "" { target c++11_down } .-1 }
 };
 
 
Index: testsuite/g++.old-deja/g++.pt/spec20.C
===================================================================
--- testsuite/g++.old-deja/g++.pt/spec20.C	(revision 276015)
+++ testsuite/g++.old-deja/g++.pt/spec20.C	(working copy)
@@ -8,7 +8,7 @@
 template <class T> 
 struct S {
   template <class U> void f(U);
-  template <> void f<int>(int); // { dg-error "" } invalid specialization
+  template <> void f<int>(int); // { dg-error "20:template-id .f<int>. in declaration|explicit specialization" }
 
   template <class V> struct I {};      // { dg-error "template" }
   template <class V> struct I<V*> {};  // { dg-error "template" }
Index: testsuite/g++.old-deja/g++.pt/spec21.C
===================================================================
--- testsuite/g++.old-deja/g++.pt/spec21.C	(revision 276015)
+++ testsuite/g++.old-deja/g++.pt/spec21.C	(working copy)
@@ -4,8 +4,8 @@ template <class T> struct S {};
 template <class T = int> struct S<T*> {}; // { dg-error "" } default argument
 
 template <int I, int J> struct A {};
-template <int I> struct A<I+5, I*2> {}; // { dg-error "" } argument involves parameter
-
+template <int I> struct A<I+5, I*2> {}; // { dg-error "28:template argument" }
+// { dg-error "33:template argument" "" { target *-*-* } .-1 }
 template <class T, T t> struct C {};
 template <class T> struct C<T, 1>;  // { dg-error "" } type depends on parameter
 int i;
Index: testsuite/g++.old-deja/g++.robertl/eb103.C
===================================================================
--- testsuite/g++.old-deja/g++.robertl/eb103.C	(revision 276015)
+++ testsuite/g++.old-deja/g++.robertl/eb103.C	(working copy)
@@ -4,7 +4,8 @@
 template <int nlimb, int i>
 inline unsigned f (unsigned* ptr);
 template <int nlimb>
-inline unsigned f<nlimb,nlimb> (unsigned* ptr) // { dg-error "partial specialization" }
+inline unsigned f<nlimb,nlimb> (unsigned* ptr)  // { dg-error "17:non-class, non-variable partial specialization" "" { target c++14 } }
+// { dg-error "17:non-type partial specialization" "" { target c++11_down } .-1 }
 {
   return 1;
 }
