Migrate "g" - "i" directory language tests off @compile-error.

The "@compile-error" comment is an old not-great way of defining static
error tests.

See: https://github.com/dart-lang/sdk/issues/45634
Change-Id: I65c446e00b25239960d421489e6cf87a88d875d5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296408
Reviewed-by: Nate Bosch <nbosch@google.com>
Commit-Queue: Nate Bosch <nbosch@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>

tests/language/generic/conflicting_generic_interfaces_hierarchy_loop_infinite_test.dart

@@ -6,9 +6,15 @@
 // There is an interface conflict here due to a loop in the class
 // hierarchy leading to an infinite set of implemented types; this loop
 // shouldn't cause non-termination.
-/*@compile-error=unspecified*/ class A<T> implements B<List<T>> {}
+class A<T> implements B<List<T>> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'A' is a supertype of itself.
 
-/*@compile-error=unspecified*/ class B<T> implements A<List<T>> {}
+class B<T> implements A<List<T>> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'B' is a supertype of itself.
 
 main() {
   new A();

tests/language/generic/conflicting_generic_interfaces_hierarchy_loop_test.dart

@@ -6,9 +6,15 @@
 // There is no interface conflict here, but there is a loop in the class
 // hierarchy leading to a finite set of implemented types; this loop
 // shouldn't cause non-termination.
-/*@compile-error=unspecified*/ class A<T> implements B<T> {}
+class A<T> implements B<T> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'A' is a supertype of itself.
 
-/*@compile-error=unspecified*/ class B<T> implements A<T> {}
+class B<T> implements A<T> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'B' is a supertype of itself.
 
 main() {
   new A();

tests/language/generic/conflicting_generic_interfaces_simple_test.dart

@@ -9,7 +9,10 @@ class A implements I<int> {}
 
 class B implements I<String> {}
 
-/*@compile-error=unspecified*/ class C extends A implements B {}
+class C extends A implements B {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.CONFLICTING_GENERIC_INTERFACES
+// [cfe] 'C' can't implement both 'I<int>' and 'I<String>'
 
 main() {
   new C();

tests/language/getter/unbound_test.dart

@@ -6,7 +6,10 @@
 class A {
   const A();
   foo() {
-    return y; /*@compile-error=unspecified*/
+    return y;
+    //     ^
+    // [analyzer] COMPILE_TIME_ERROR.UNDEFINED_IDENTIFIER
+    // [cfe] The getter 'y' isn't defined for the class 'A'.
   }
 }
 

tests/language/import/transitive_private_library_access_test.dart

@@ -9,5 +9,8 @@ import 'dart:typed_data';
 import 'package:expect/expect.dart';
 
 main() {
-  ClassID.GetID(4); /*@compile-error=unspecified*/
+  ClassID.GetID(4);
+//^^^^^^^
+// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_IDENTIFIER
+// [cfe] Undefined name 'ClassID'.
 }

tests/language/inference/circularity_test.dart

@@ -2,8 +2,13 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-var /*@compile-error=unspecified*/ x = () => y;
-var /*@compile-error=unspecified*/ y = () => x;
+var x = () => y;
+//  ^
+// [analyzer] COMPILE_TIME_ERROR.TOP_LEVEL_CYCLE
+// [cfe] Can't infer the type of 'x': circularity found during type inference.
+var y = () => x;
+//  ^
+// [analyzer] COMPILE_TIME_ERROR.TOP_LEVEL_CYCLE
 
 void main() {
   x;

tests/language/initializing_formal/final_test.dart

@@ -10,7 +10,10 @@ class A {
   // initializing formal.
   A(this.x)
       : y = (() {
-          /*@compile-error=unspecified*/ x = 3;
+          x = 3;
+//        ^
+// [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_LOCAL
+// [cfe] Can't assign to the final variable 'x'.
         });
 }
 

tests/language_2/generic/conflicting_generic_interfaces_hierarchy_loop_infinite_test.dart

@@ -8,9 +8,15 @@
 // There is an interface conflict here due to a loop in the class
 // hierarchy leading to an infinite set of implemented types; this loop
 // shouldn't cause non-termination.
-/*@compile-error=unspecified*/ class A<T> implements B<List<T>> {}
+class A<T> implements B<List<T>> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'A' is a supertype of itself.
 
-/*@compile-error=unspecified*/ class B<T> implements A<List<T>> {}
+class B<T> implements A<List<T>> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'B' is a supertype of itself.
 
 main() {
   new A();

tests/language_2/generic/conflicting_generic_interfaces_hierarchy_loop_test.dart

@@ -8,9 +8,15 @@
 // There is no interface conflict here, but there is a loop in the class
 // hierarchy leading to a finite set of implemented types; this loop
 // shouldn't cause non-termination.
-/*@compile-error=unspecified*/ class A<T> implements B<T> {}
+class A<T> implements B<T> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'A' is a supertype of itself.
 
-/*@compile-error=unspecified*/ class B<T> implements A<T> {}
+class B<T> implements A<T> {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.RECURSIVE_INTERFACE_INHERITANCE
+// [cfe] 'B' is a supertype of itself.
 
 main() {
   new A();

tests/language_2/generic/conflicting_generic_interfaces_simple_test.dart

@@ -11,7 +11,10 @@ class A implements I<int> {}
 
 class B implements I<String> {}
 
-/*@compile-error=unspecified*/ class C extends A implements B {}
+class C extends A implements B {}
+//    ^
+// [analyzer] COMPILE_TIME_ERROR.CONFLICTING_GENERIC_INTERFACES
+// [cfe] 'C' can't implement both 'I<int>' and 'I<String>'
 
 main() {
   new C();

tests/language_2/getter/unbound_test.dart

@@ -8,7 +8,10 @@
 class A {
   const A();
   foo() {
-    return y; /*@compile-error=unspecified*/
+    return y;
+    //     ^
+    // [analyzer] COMPILE_TIME_ERROR.UNDEFINED_IDENTIFIER
+    // [cfe] The getter 'y' isn't defined for the class 'A'.
   }
 }
 

tests/language_2/import/transitive_private_library_access_test.dart

@@ -11,5 +11,8 @@ import 'dart:typed_data';
 import 'package:expect/expect.dart';
 
 main() {
-  ClassID.GetID(4); /*@compile-error=unspecified*/
+  ClassID.GetID(4);
+//^^^^^^^
+// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_IDENTIFIER
+// [cfe] Undefined name 'ClassID'.
 }

tests/language_2/inference/circularity_test.dart

@@ -4,8 +4,13 @@
 
 // @dart = 2.9
 
-var /*@compile-error=unspecified*/ x = () => y;
-var /*@compile-error=unspecified*/ y = () => x;
+var x = () => y;
+//  ^
+// [analyzer] COMPILE_TIME_ERROR.TOP_LEVEL_CYCLE
+// [cfe] Can't infer the type of 'x': circularity found during type inference.
+var y = () => x;
+//  ^
+// [analyzer] COMPILE_TIME_ERROR.TOP_LEVEL_CYCLE
 
 void main() {
   x;

tests/language_2/initializing_formal/final_test.dart

@@ -12,7 +12,10 @@ class A {
   // initializing formal.
   A(this.x)
       : y = (() {
-          /*@compile-error=unspecified*/ x = 3;
+          x = 3;
+//        ^
+// [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_FINAL_LOCAL
+// [cfe] Can't assign to the final variable 'x'.
         });
 }
 

tests/language_2/initializing_formal/type_test.dart

@@ -12,7 +12,10 @@ class A {
   // Finding the type of an initializing formal: should cause an error
   // in the initializer but not the body, because the former has type
   // `int` and the latter has type `num`.
-  A(int this.x) : /*@compile-error=unspecified*/ y = x {
+  A(int this.x) : y = x {
+    //                ^
+    // [analyzer] COMPILE_TIME_ERROR.FIELD_INITIALIZER_NOT_ASSIGNABLE
+    // [cfe] A value of type 'int' can't be assigned to a variable of type 'double'.
     y = x;
   }
 }

tests/language_2/invalid_returns/async_invalid_return_05_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_08_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Object v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_11_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_14_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_17_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<Object> v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_20_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<Object> v = null;
 void test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_23_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Object test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_24_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<void> v = null;
 Object test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_25_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<void> v = null;
 Object test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_26_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Future<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_27_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<void> v = null;
 Future<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_28_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<void> v = null;
 Future<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_29_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 FutureOr<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_30_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<void> v = null;
 FutureOr<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_31_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<void> v = null;
 FutureOr<int> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_32_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Future<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_33_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<void> v = null;
 Future<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_34_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<void> v = null;
 Future<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_35_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 FutureOr<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_36_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<void> v = null;
 FutureOr<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_37_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<void> v = null;
 FutureOr<Object> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_38_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 Future<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_39_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 Future<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_40_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 Future<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_41_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<Future<String>> v = null;
 Future<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<Future<String>>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_42_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 FutureOr<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_43_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 FutureOr<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_44_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 FutureOr<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/async_invalid_return_45_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<Future<String>> v = null;
 FutureOr<String> test() async {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<Future<String>>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_06_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_07_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Object v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_08_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_09_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_10_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<Object> v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_11_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<Object> v = null;
 void test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] Can't return a value from a void function.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_12_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 int test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_13_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Object test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_14_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Future<int> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_15_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 FutureOr<int> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_16_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 Future<Object> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_17_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 void v = null;
 FutureOr<Object> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] This expression has type 'void' and can't be used.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_18_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 String test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'int' can't be assigned to a variable of type 'String'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_19_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 String test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'String'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_20_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 String test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'FutureOr<int>' can't be assigned to a variable of type 'String'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_21_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 Future<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'int' can't be assigned to a variable of type 'Future<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_22_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 Future<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'Future<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_23_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 Future<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'FutureOr<int>' can't be assigned to a variable of type 'Future<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_24_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 int v = null;
 FutureOr<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'int' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_25_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 Future<int> v = null;
 FutureOr<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'Future<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {

tests/language_2/invalid_returns/sync_invalid_return_26_test.dart

@@ -12,7 +12,10 @@ import 'dart:async';
 */
 FutureOr<int> v = null;
 FutureOr<String> test() {
-  return /*@compile-error=unspecified*/ v;
+  return v;
+  //     ^
+  // [analyzer] COMPILE_TIME_ERROR.RETURN_OF_INVALID_TYPE
+  // [cfe] A value of type 'FutureOr<int>' can't be assigned to a variable of type 'FutureOr<String>'.
 }
 
 void main() {