[cfe] Allow generic metadata through experimental flag

Change-Id: If6dc5381546c2814cd838aee8ab7d6dc11e9106f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/185544
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Dmitry Stefantsov <dmitryas@google.com>

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -4392,8 +4392,10 @@ class BodyBuilder extends ScopeListener<JumpTarget>
     String name = pop();
     List<UnresolvedType> typeArguments = pop();
     if (inMetadata && typeArguments != null) {
-      handleRecoverableError(fasta.messageMetadataTypeArguments,
-          nameLastToken.next, nameLastToken.next);
+      if (!libraryBuilder.enableGenericMetadataInLibrary) {
+        handleRecoverableError(fasta.messageMetadataTypeArguments,
+            nameLastToken.next, nameLastToken.next);
+      }
     }
 
     Object type = pop();

pkg/front_end/lib/src/fasta/source/source_library_builder.dart

@@ -298,6 +298,7 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
   Version _enableNonNullableVersionInLibrary;
   bool _enableTripleShiftInLibrary;
   bool _enableExtensionMethodsInLibrary;
+  bool _enableGenericMetadataInLibrary;
 
   bool get enableVarianceInLibrary =>
       _enableVarianceInLibrary ??= loader.target.isExperimentEnabledInLibrary(
@@ -332,6 +333,10 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
           .isExperimentEnabledInLibrary(
               ExperimentalFlag.extensionMethods, _packageUri ?? importUri);
 
+  bool get enableGenericMetadataInLibrary => _enableGenericMetadataInLibrary ??=
+      loader.target.isExperimentEnabledInLibrary(
+          ExperimentalFlag.genericMetadata, _packageUri ?? importUri);
+
   void updateLibraryNNBDSettings() {
     library.isNonNullableByDefault = isNonNullableByDefault;
     if (enableNonNullableInLibrary) {

pkg/front_end/testcases/generic_metadata/folder.options

@@ -0,0 +1 @@
+--enable-experiment=generic-metadata

pkg/front_end/testcases/generic_metadata/generic_metadata.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+class A<T> {
+  const A();
+}
+
+class B<S, T> {
+  const B();
+}
+
+class C<T extends num> {
+  const C();
+}
+
+class D<S extends num, T extends S> {
+  const D();
+}
+
+@A<int, num>() // error
+@B<int>() // error
+@C<String>() // error
+@D<int, num>() // error
+test() {}
+
+@A() // ok
+@A<int>() // ok
+@B() // ok
+@B<int, String>() // ok
+@C() // ok
+@C<num>() // ok
+@C<int>() // ok
+@D() // ok
+@D<num, num>() // ok
+@D<num, int>() // ok
+main() {}

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.expect

@@ -0,0 +1,99 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+// @A<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:6:9: Context: Found this candidate, but the arguments don't match.
+//   const A();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+// @B<int>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:10:9: Context: Found this candidate, but the arguments don't match.
+//   const B();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:23:2: Error: Type argument 'String' doesn't conform to the bound 'num' of the type variable 'T' on 'C'.
+// Try changing type arguments so that they conform to the bounds.
+// @C<String>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:13:9: Context: This is the type variable whose bound isn't conformed to.
+// class C<T extends num> {
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:24:2: Error: Type argument 'num' doesn't conform to the bound 'S' of the type variable 'T' on 'D'.
+// Try changing type arguments so that they conform to the bounds.
+// @D<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:17:24: Context: This is the type variable whose bound isn't conformed to.
+// class D<S extends num, T extends S> {
+//                        ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::A<self::A::T%>
+    : super core::Object::•()
+    ;
+}
+class B<S extends core::Object? = dynamic, T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::B<self::B::S%, self::B::T%>
+    : super core::Object::•()
+    ;
+}
+class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::C<self::C::T>
+    : super core::Object::•()
+    ;
+}
+class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::D<self::D::S, self::D::T>
+    : super core::Object::•()
+    ;
+}
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+@A<int, num>() // error
+ ^"
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+@B<int>() // error
+ ^"
+@#C1
+@#C2
+static method test() → dynamic {}
+@#C3
+@#C4
+@#C5
+@#C6
+@#C7
+@#C7
+@#C8
+@#C9
+@#C9
+@#C10
+static method main() → dynamic {}
+
+constants  {
+  #C1 = self::C<core::String> {}
+  #C2 = self::D<core::int, core::num> {}
+  #C3 = self::A<dynamic> {}
+  #C4 = self::A<core::int> {}
+  #C5 = self::B<dynamic, dynamic> {}
+  #C6 = self::B<core::int, core::String> {}
+  #C7 = self::C<core::num> {}
+  #C8 = self::C<core::int> {}
+  #C9 = self::D<core::num, core::num> {}
+  #C10 = self::D<core::num, core::int> {}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///generic_metadata.dart:
+- C. (from org-dartlang-testcase:///generic_metadata.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
+- D. (from org-dartlang-testcase:///generic_metadata.dart:18:9)
+- A. (from org-dartlang-testcase:///generic_metadata.dart:6:9)
+- B. (from org-dartlang-testcase:///generic_metadata.dart:10:9)

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.transformed.expect

@@ -0,0 +1,99 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+// @A<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:6:9: Context: Found this candidate, but the arguments don't match.
+//   const A();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+// @B<int>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:10:9: Context: Found this candidate, but the arguments don't match.
+//   const B();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:23:2: Error: Type argument 'String' doesn't conform to the bound 'num' of the type variable 'T' on 'C'.
+// Try changing type arguments so that they conform to the bounds.
+// @C<String>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:13:9: Context: This is the type variable whose bound isn't conformed to.
+// class C<T extends num> {
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:24:2: Error: Type argument 'num' doesn't conform to the bound 'S' of the type variable 'T' on 'D'.
+// Try changing type arguments so that they conform to the bounds.
+// @D<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:17:24: Context: This is the type variable whose bound isn't conformed to.
+// class D<S extends num, T extends S> {
+//                        ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::A<self::A::T%>
+    : super core::Object::•()
+    ;
+}
+class B<S extends core::Object? = dynamic, T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::B<self::B::S%, self::B::T%>
+    : super core::Object::•()
+    ;
+}
+class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::C<self::C::T>
+    : super core::Object::•()
+    ;
+}
+class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::D<self::D::S, self::D::T>
+    : super core::Object::•()
+    ;
+}
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+@A<int, num>() // error
+ ^"
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+@B<int>() // error
+ ^"
+@#C1
+@#C2
+static method test() → dynamic {}
+@#C3
+@#C4
+@#C5
+@#C6
+@#C7
+@#C7
+@#C8
+@#C9
+@#C9
+@#C10
+static method main() → dynamic {}
+
+constants  {
+  #C1 = self::C<core::String> {}
+  #C2 = self::D<core::int, core::num> {}
+  #C3 = self::A<dynamic> {}
+  #C4 = self::A<core::int> {}
+  #C5 = self::B<dynamic, dynamic> {}
+  #C6 = self::B<core::int, core::String> {}
+  #C7 = self::C<core::num> {}
+  #C8 = self::C<core::int> {}
+  #C9 = self::D<core::num, core::num> {}
+  #C10 = self::D<core::num, core::int> {}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///generic_metadata.dart:
+- C. (from org-dartlang-testcase:///generic_metadata.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
+- D. (from org-dartlang-testcase:///generic_metadata.dart:18:9)
+- A. (from org-dartlang-testcase:///generic_metadata.dart:6:9)
+- B. (from org-dartlang-testcase:///generic_metadata.dart:10:9)

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.textual_outline.expect

@@ -0,0 +1,28 @@
+class A<T> {
+  const A();
+}
+class B<S, T> {
+  const B();
+}
+class C<T extends num> {
+  const C();
+}
+class D<S extends num, T extends S> {
+  const D();
+}
+@A<int, num>()
+@B<int>()
+@C<String>()
+@D<int, num>()
+test() {}
+@A()
+@A<int>()
+@B()
+@B<int, String>()
+@C()
+@C<num>()
+@C<int>()
+@D()
+@D<num, num>()
+@D<num, int>()
+main() {}

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.expect

@@ -0,0 +1,99 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+// @A<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:6:9: Context: Found this candidate, but the arguments don't match.
+//   const A();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+// @B<int>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:10:9: Context: Found this candidate, but the arguments don't match.
+//   const B();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:23:2: Error: Type argument 'String' doesn't conform to the bound 'num' of the type variable 'T' on 'C'.
+// Try changing type arguments so that they conform to the bounds.
+// @C<String>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:13:9: Context: This is the type variable whose bound isn't conformed to.
+// class C<T extends num> {
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:24:2: Error: Type argument 'num' doesn't conform to the bound 'S' of the type variable 'T' on 'D'.
+// Try changing type arguments so that they conform to the bounds.
+// @D<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:17:24: Context: This is the type variable whose bound isn't conformed to.
+// class D<S extends num, T extends S> {
+//                        ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::A<self::A::T%>
+    : super core::Object::•()
+    ;
+}
+class B<S extends core::Object? = dynamic, T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::B<self::B::S%, self::B::T%>
+    : super core::Object::•()
+    ;
+}
+class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::C<self::C::T>
+    : super core::Object::•()
+    ;
+}
+class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::D<self::D::S, self::D::T>
+    : super core::Object::•()
+    ;
+}
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+@A<int, num>() // error
+ ^"
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+@B<int>() // error
+ ^"
+@#C1
+@#C2
+static method test() → dynamic {}
+@#C3
+@#C4
+@#C5
+@#C6
+@#C7
+@#C7
+@#C8
+@#C9
+@#C9
+@#C10
+static method main() → dynamic {}
+
+constants  {
+  #C1 = self::C<core::String*> {}
+  #C2 = self::D<core::int*, core::num*> {}
+  #C3 = self::A<dynamic> {}
+  #C4 = self::A<core::int*> {}
+  #C5 = self::B<dynamic, dynamic> {}
+  #C6 = self::B<core::int*, core::String*> {}
+  #C7 = self::C<core::num*> {}
+  #C8 = self::C<core::int*> {}
+  #C9 = self::D<core::num*, core::num*> {}
+  #C10 = self::D<core::num*, core::int*> {}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///generic_metadata.dart:
+- C. (from org-dartlang-testcase:///generic_metadata.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
+- D. (from org-dartlang-testcase:///generic_metadata.dart:18:9)
+- A. (from org-dartlang-testcase:///generic_metadata.dart:6:9)
+- B. (from org-dartlang-testcase:///generic_metadata.dart:10:9)

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.outline.expect

@@ -0,0 +1,95 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+// @A<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:6:9: Context: Found this candidate, but the arguments don't match.
+//   const A();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+// @B<int>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:10:9: Context: Found this candidate, but the arguments don't match.
+//   const B();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:23:2: Error: Type argument 'String' doesn't conform to the bound 'num' of the type variable 'T' on 'C'.
+// Try changing type arguments so that they conform to the bounds.
+// @C<String>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:13:9: Context: This is the type variable whose bound isn't conformed to.
+// class C<T extends num> {
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:24:2: Error: Type argument 'num' doesn't conform to the bound 'S' of the type variable 'T' on 'D'.
+// Try changing type arguments so that they conform to the bounds.
+// @D<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:17:24: Context: This is the type variable whose bound isn't conformed to.
+// class D<S extends num, T extends S> {
+//                        ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::A<self::A::T%>
+    : super core::Object::•()
+    ;
+}
+class B<S extends core::Object? = dynamic, T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::B<self::B::S%, self::B::T%>
+    : super core::Object::•()
+    ;
+}
+class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::C<self::C::T>
+    : super core::Object::•()
+    ;
+}
+class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::D<self::D::S, self::D::T>
+    : super core::Object::•()
+    ;
+}
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+@A<int, num>() // error
+ ^"
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+@B<int>() // error
+ ^"
+@self::C::•<core::String>()
+@self::D::•<core::int, core::num>()
+static method test() → dynamic
+  ;
+@self::A::•<dynamic>()
+@self::A::•<core::int>()
+@self::B::•<dynamic, dynamic>()
+@self::B::•<core::int, core::String>()
+@self::C::•<core::num>()
+@self::C::•<core::num>()
+@self::C::•<core::int>()
+@self::D::•<core::num, core::num>()
+@self::D::•<core::num, core::num>()
+@self::D::•<core::num, core::int>()
+static method main() → dynamic
+  ;
+
+
+Extra constant evaluation status:
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:23:2 -> InstanceConstant(const C<String*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:24:2 -> InstanceConstant(const D<int*, num*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:27:2 -> InstanceConstant(const A<dynamic>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:28:2 -> InstanceConstant(const A<int*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:29:2 -> InstanceConstant(const B<dynamic, dynamic>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:30:2 -> InstanceConstant(const B<int*, String*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:31:2 -> InstanceConstant(const C<num*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:32:2 -> InstanceConstant(const C<num*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:33:2 -> InstanceConstant(const C<int*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:34:2 -> InstanceConstant(const D<num*, num*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:35:2 -> InstanceConstant(const D<num*, num*>{})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///generic_metadata.dart:36:2 -> InstanceConstant(const D<num*, int*>{})
+Extra constant evaluation: evaluated: 12, effectively constant: 12

pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.transformed.expect

@@ -0,0 +1,99 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+// @A<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:6:9: Context: Found this candidate, but the arguments don't match.
+//   const A();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+// @B<int>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:10:9: Context: Found this candidate, but the arguments don't match.
+//   const B();
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:23:2: Error: Type argument 'String' doesn't conform to the bound 'num' of the type variable 'T' on 'C'.
+// Try changing type arguments so that they conform to the bounds.
+// @C<String>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:13:9: Context: This is the type variable whose bound isn't conformed to.
+// class C<T extends num> {
+//         ^
+//
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:24:2: Error: Type argument 'num' doesn't conform to the bound 'S' of the type variable 'T' on 'D'.
+// Try changing type arguments so that they conform to the bounds.
+// @D<int, num>() // error
+//  ^
+// pkg/front_end/testcases/generic_metadata/generic_metadata.dart:17:24: Context: This is the type variable whose bound isn't conformed to.
+// class D<S extends num, T extends S> {
+//                        ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::A<self::A::T%>
+    : super core::Object::•()
+    ;
+}
+class B<S extends core::Object? = dynamic, T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::B<self::B::S%, self::B::T%>
+    : super core::Object::•()
+    ;
+}
+class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::C<self::C::T>
+    : super core::Object::•()
+    ;
+}
+class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+  const constructor •() → self::D<self::D::S, self::D::T>
+    : super core::Object::•()
+    ;
+}
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:21:2: Error: Expected 1 type arguments.
+@A<int, num>() // error
+ ^"
+@invalid-expression "pkg/front_end/testcases/generic_metadata/generic_metadata.dart:22:2: Error: Expected 2 type arguments.
+@B<int>() // error
+ ^"
+@#C1
+@#C2
+static method test() → dynamic {}
+@#C3
+@#C4
+@#C5
+@#C6
+@#C7
+@#C7
+@#C8
+@#C9
+@#C9
+@#C10
+static method main() → dynamic {}
+
+constants  {
+  #C1 = self::C<core::String*> {}
+  #C2 = self::D<core::int*, core::num*> {}
+  #C3 = self::A<dynamic> {}
+  #C4 = self::A<core::int*> {}
+  #C5 = self::B<dynamic, dynamic> {}
+  #C6 = self::B<core::int*, core::String*> {}
+  #C7 = self::C<core::num*> {}
+  #C8 = self::C<core::int*> {}
+  #C9 = self::D<core::num*, core::num*> {}
+  #C10 = self::D<core::num*, core::int*> {}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///generic_metadata.dart:
+- C. (from org-dartlang-testcase:///generic_metadata.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
+- D. (from org-dartlang-testcase:///generic_metadata.dart:18:9)
+- A. (from org-dartlang-testcase:///generic_metadata.dart:6:9)
+- B. (from org-dartlang-testcase:///generic_metadata.dart:10:9)

pkg/front_end/testcases/textual_outline.status

@@ -62,6 +62,7 @@ general/null_safety_invalid_experiment: FormatterCrash
 general/null_safety_invalid_experiment_and_language_version: FormatterCrash
 general/type_parameters_on_void: FormatterCrash
 general/var_as_type_name: FormatterCrash
+generic_metadata/generic_metadata: FormatterCrash
 inference/unsafe_block_closure_inference_function_call_explicit_dynamic_param_via_expr1: FormatterCrash
 inference/unsafe_block_closure_inference_function_call_explicit_type_param_via_expr1: FormatterCrash
 late_lowering/covariant_late_field: FormatterCrash