[cfe] Preserve the required flag in synthesized mixin constructors

Closes https://github.com/dart-lang/sdk/issues/52872

Change-Id: I9089683f4fb2027211c96ad2065044c8181a282f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/313781
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Chloe Stefantsova <cstefantsova@google.com>

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

@@ -1007,6 +1007,7 @@ class KernelTarget extends TargetImplementation {
       VariableDeclaration copy = new VariableDeclaration(formal.name,
           isFinal: formal.isFinal,
           isConst: formal.isConst,
+          isRequired: formal.isRequired,
           hasDeclaredInitializer: formal.hasDeclaredInitializer,
           type: const UnknownType());
       if (!hasTypeDependency && formal.type is! UnknownType) {

pkg/front_end/testcases/general/issue52872.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2023, 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 {
+  bool v1;
+  num v2;
+  A(bool this.v1, {required num this.v2});
+}
+
+mixin class M1 {
+  num v2 = -1;
+}
+
+class C = A with M1;
+
+test() {
+  C c = C(true);
+}

pkg/front_end/testcases/general/issue52872.dart.strong.expect

@@ -0,0 +1,45 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+//   C c = C(true);
+//          ^
+// pkg/front_end/testcases/general/issue52872.dart:15:7: Context: The class 'C' has a constructor that takes no arguments.
+// class C = A with M1;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = #C1}) → self::A
+    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •() → self::M1
+    : super core::Object::•()
+    ;
+}
+class C = self::A with self::M1 {
+  synthetic constructor •(core::bool v1, {required core::num v2 = #C1}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+  mixin-super-stub get v2() → core::num
+    return super.{self::M1::v2};
+  mixin-super-stub set v2(core::num value) → void
+    return super.{self::M1::v2} = value;
+}
+static method test() → dynamic {
+  self::C c = invalid-expression "pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+  C c = C(true);
+         ^";
+}
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/general/issue52872.dart.strong.transformed.expect

@@ -0,0 +1,47 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+//   C c = C(true);
+//          ^
+// pkg/front_end/testcases/general/issue52872.dart:15:7: Context: The class 'C' has a constructor that takes no arguments.
+// class C = A with M1;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = #C1}) → self::A
+    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •() → self::M1
+    : super core::Object::•()
+    ;
+}
+class C extends self::A implements self::M1 /*isEliminatedMixin*/  {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •(core::bool v1, {required core::num v2 = #C1}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+}
+static method test() → dynamic {
+  self::C c = invalid-expression "pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+  C c = C(true);
+         ^";
+}
+
+constants  {
+  #C1 = null
+}
+
+Extra constant evaluation status:
+Evaluated: InstanceInvocation @ org-dartlang-testcase:///issue52872.dart:12:12 -> IntConstant(-1)
+Evaluated: InstanceInvocation @ org-dartlang-testcase:///issue52872.dart:12:12 -> IntConstant(-1)
+Extra constant evaluation: evaluated: 6, effectively constant: 2

pkg/front_end/testcases/general/issue52872.dart.textual_outline.expect

@@ -0,0 +1,12 @@
+class A {
+  bool v1;
+  num v2;
+  A(bool this.v1, {required num this.v2});
+}
+
+mixin class M1 {
+  num v2 = -1;
+}
+
+class C = A with M1;
+test() {}

pkg/front_end/testcases/general/issue52872.dart.textual_outline_modelled.expect

@@ -0,0 +1,13 @@
+class A {
+  A(bool this.v1, {required num this.v2});
+  bool v1;
+  num v2;
+}
+
+class C = A with M1;
+
+mixin class M1 {
+  num v2 = -1;
+}
+
+test() {}

pkg/front_end/testcases/general/issue52872.dart.weak.expect

@@ -0,0 +1,45 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+//   C c = C(true);
+//          ^
+// pkg/front_end/testcases/general/issue52872.dart:15:7: Context: The class 'C' has a constructor that takes no arguments.
+// class C = A with M1;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = #C1}) → self::A
+    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •() → self::M1
+    : super core::Object::•()
+    ;
+}
+class C = self::A with self::M1 {
+  synthetic constructor •(core::bool v1, {required core::num v2 = #C1}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+  mixin-super-stub get v2() → core::num
+    return super.{self::M1::v2};
+  mixin-super-stub set v2(core::num value) → void
+    return super.{self::M1::v2} = value;
+}
+static method test() → dynamic {
+  self::C c = invalid-expression "pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+  C c = C(true);
+         ^";
+}
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/general/issue52872.dart.weak.modular.expect

@@ -0,0 +1,45 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+//   C c = C(true);
+//          ^
+// pkg/front_end/testcases/general/issue52872.dart:15:7: Context: The class 'C' has a constructor that takes no arguments.
+// class C = A with M1;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = #C1}) → self::A
+    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •() → self::M1
+    : super core::Object::•()
+    ;
+}
+class C = self::A with self::M1 {
+  synthetic constructor •(core::bool v1, {required core::num v2 = #C1}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+  mixin-super-stub get v2() → core::num
+    return super.{self::M1::v2};
+  mixin-super-stub set v2(core::num value) → void
+    return super.{self::M1::v2} = value;
+}
+static method test() → dynamic {
+  self::C c = invalid-expression "pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+  C c = C(true);
+         ^";
+}
+
+constants  {
+  #C1 = null
+}

pkg/front_end/testcases/general/issue52872.dart.weak.outline.expect

@@ -0,0 +1,26 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = null}) → self::A
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2;
+  synthetic constructor •() → self::M1
+    ;
+}
+class C = self::A with self::M1 {
+  synthetic constructor •(core::bool v1, {required core::num v2 = null}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+  mixin-super-stub get v2() → core::num
+    return super.{self::M1::v2};
+  mixin-super-stub set v2(core::num value) → void
+    return super.{self::M1::v2} = value;
+}
+static method test() → dynamic
+  ;

pkg/front_end/testcases/general/issue52872.dart.weak.transformed.expect

@@ -0,0 +1,47 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+//   C c = C(true);
+//          ^
+// pkg/front_end/testcases/general/issue52872.dart:15:7: Context: The class 'C' has a constructor that takes no arguments.
+// class C = A with M1;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::bool v1;
+  field core::num v2;
+  constructor •(core::bool v1, {required core::num v2 = #C1}) → self::A
+    : self::A::v1 = v1, self::A::v2 = v2, super core::Object::•()
+    ;
+}
+mixin class M1 extends core::Object {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •() → self::M1
+    : super core::Object::•()
+    ;
+}
+class C extends self::A implements self::M1 /*isEliminatedMixin*/  {
+  field core::num v2 = 1.{core::int::unary-}(){() → core::int};
+  synthetic constructor •(core::bool v1, {required core::num v2 = #C1}) → self::C
+    : super self::A::•(v1, v2: v2)
+    ;
+}
+static method test() → dynamic {
+  self::C c = invalid-expression "pkg/front_end/testcases/general/issue52872.dart:18:10: Error: Required named parameter 'v2' must be provided.
+  C c = C(true);
+         ^";
+}
+
+constants  {
+  #C1 = null
+}
+
+Extra constant evaluation status:
+Evaluated: InstanceInvocation @ org-dartlang-testcase:///issue52872.dart:12:12 -> IntConstant(-1)
+Evaluated: InstanceInvocation @ org-dartlang-testcase:///issue52872.dart:12:12 -> IntConstant(-1)
+Extra constant evaluation: evaluated: 6, effectively constant: 2

pkg/front_end/testcases/super_parameters/issue48708.dart.strong.expect

@@ -16,7 +16,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin = self::B<self::A> with self::Mixin /*isAnonymousMixin*/  {
-  synthetic constructor •({self::A field = #C1}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = #C1}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }

pkg/front_end/testcases/super_parameters/issue48708.dart.strong.transformed.expect

@@ -16,7 +16,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin extends self::B<self::A> implements self::Mixin /*isAnonymousMixin,isEliminatedMixin*/  {
-  synthetic constructor •({self::A field = #C1}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = #C1}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }

pkg/front_end/testcases/super_parameters/issue48708.dart.weak.expect

@@ -16,7 +16,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin = self::B<self::A> with self::Mixin /*isAnonymousMixin*/  {
-  synthetic constructor •({self::A field = #C1}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = #C1}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }

pkg/front_end/testcases/super_parameters/issue48708.dart.weak.modular.expect

@@ -16,7 +16,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin = self::B<self::A> with self::Mixin /*isAnonymousMixin*/  {
-  synthetic constructor •({self::A field = #C1}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = #C1}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }

pkg/front_end/testcases/super_parameters/issue48708.dart.weak.outline.expect

@@ -14,7 +14,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin = self::B<self::A> with self::Mixin /*isAnonymousMixin*/  {
-  synthetic constructor •({self::A field = null}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = null}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }

pkg/front_end/testcases/super_parameters/issue48708.dart.weak.transformed.expect

@@ -16,7 +16,7 @@ abstract class B<D extends core::Object? = dynamic> extends core::Object {
     ;
 }
 abstract class _C&B&Mixin extends self::B<self::A> implements self::Mixin /*isAnonymousMixin,isEliminatedMixin*/  {
-  synthetic constructor •({self::A field = #C1}) → self::_C&B&Mixin
+  synthetic constructor •({required self::A field = #C1}) → self::_C&B&Mixin
     : super self::B::•(field: field)
     ;
 }