[cfe] Handle non-const records in const constructors

The initializer was built in an 'inferred' rather than a 'required'
constant context, meaning that it would be encoded as a declaratively
constant literal instead of a structurally constant literal.

Closes #50132

Change-Id: I58b995d879efd2ec374b711718b63ac8f122bcfc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/262349
Commit-Queue: Johnni Winther <[email protected]>
Reviewed-by: Chloe Stefantsova <[email protected]>

Author: johnniwinther

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

@@ -771,7 +771,7 @@ class DietListener extends StackListenerImpl {
     TypeInferrer typeInferrer = typeInferenceEngine.createLocalTypeInferrer(
         uri, thisType, libraryBuilder, inferenceDataForTesting);
     ConstantContext constantContext = builder.isConstructor && builder.isConst
-        ? ConstantContext.inferred
+        ? ConstantContext.required
         : ConstantContext.none;
     return createListenerInternal(
         builder,

pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart.strong.expect

@@ -7,6 +7,11 @@ library /*isNonNullableByDefault*/;
 // const var4 = C();
 //              ^
 //
+// pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:12: Error: Constant expression expected.
+// Try inserting 'const'.
+//     return Simple2(this.name);
+//            ^^^^^^^
+//
 // pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:5: Error: Constructors can't have a return type.
 // Try removing the return type.
 //     return Simple2(this.name);

pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart.strong.transformed.expect

@@ -7,6 +7,11 @@ library /*isNonNullableByDefault*/;
 // const var4 = C();
 //              ^
 //
+// pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:12: Error: Constant expression expected.
+// Try inserting 'const'.
+//     return Simple2(this.name);
+//            ^^^^^^^
+//
 // pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:5: Error: Constructors can't have a return type.
 // Try removing the return type.
 //     return Simple2(this.name);

pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart.weak.expect

@@ -7,6 +7,11 @@ library /*isNonNullableByDefault*/;
 // const var4 = C();
 //              ^
 //
+// pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:12: Error: Constant expression expected.
+// Try inserting 'const'.
+//     return Simple2(this.name);
+//            ^^^^^^^
+//
 // pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:5: Error: Constructors can't have a return type.
 // Try removing the return type.
 //     return Simple2(this.name);

pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart.weak.modular.expect

@@ -7,6 +7,11 @@ library /*isNonNullableByDefault*/;
 // const var4 = C();
 //              ^
 //
+// pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:12: Error: Constant expression expected.
+// Try inserting 'const'.
+//     return Simple2(this.name);
+//            ^^^^^^^
+//
 // pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:5: Error: Constructors can't have a return type.
 // Try removing the return type.
 //     return Simple2(this.name);

pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart.weak.transformed.expect

@@ -7,6 +7,11 @@ library /*isNonNullableByDefault*/;
 // const var4 = C();
 //              ^
 //
+// pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:12: Error: Constant expression expected.
+// Try inserting 'const'.
+//     return Simple2(this.name);
+//            ^^^^^^^
+//
 // pkg/front_end/testcases/const_functions/const_functions_const_ctor_error.dart:26:5: Error: Constructors can't have a return type.
 // Try removing the return type.
 //     return Simple2(this.name);

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart

@@ -0,0 +1,27 @@
+// Copyright (c) 2022, 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 Class1 {
+  final field;
+
+  const Class1() : field = []; // Error
+}
+
+class Class2 {
+  final field;
+
+  const Class2() : field = const []; // Ok
+}
+
+class Class3 {
+  final field;
+
+  const Class3() : field = Class2(); // Error
+}
+
+class Class4 {
+  final field;
+
+  const Class4() : field = const Class2(); // Ok
+}

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.textual_outline.expect

@@ -0,0 +1,19 @@
+class Class1 {
+  final field;
+  const Class1() : field = [];
+}
+
+class Class2 {
+  final field;
+  const Class2() : field = const [];
+}
+
+class Class3 {
+  final field;
+  const Class3() : field = Class2();
+}
+
+class Class4 {
+  final field;
+  const Class4() : field = const Class2();
+}

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.textual_outline_modelled.expect

@@ -0,0 +1,19 @@
+class Class1 {
+  const Class1() : field = [];
+  final field;
+}
+
+class Class2 {
+  const Class2() : field = const [];
+  final field;
+}
+
+class Class3 {
+  const Class3() : field = Class2();
+  final field;
+}
+
+class Class4 {
+  const Class4() : field = const Class2();
+  final field;
+}

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.weak.expect

@@ -0,0 +1,52 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:8:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class1() : field = []; // Error
+//                            ^
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:20:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class3() : field = Class2(); // Error
+//                            ^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class Class1 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class1
+    : self::Class1::field = <dynamic>[], super core::Object::•()
+    ;
+}
+class Class2 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class2
+    : self::Class2::field = #C1, super core::Object::•()
+    ;
+}
+class Class3 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class3
+    : self::Class3::field = #C2, super core::Object::•()
+    ;
+}
+class Class4 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class4
+    : self::Class4::field = #C2, super core::Object::•()
+    ;
+}
+
+constants  {
+  #C1 = <dynamic>[]
+  #C2 = self::Class2 {field:#C1}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///inferred_const_initializer.dart:
+- Class2. (from org-dartlang-testcase:///inferred_const_initializer.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.weak.modular.expect

@@ -0,0 +1,52 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:8:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class1() : field = []; // Error
+//                            ^
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:20:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class3() : field = Class2(); // Error
+//                            ^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class Class1 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class1
+    : self::Class1::field = <dynamic>[], super core::Object::•()
+    ;
+}
+class Class2 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class2
+    : self::Class2::field = #C1, super core::Object::•()
+    ;
+}
+class Class3 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class3
+    : self::Class3::field = #C2, super core::Object::•()
+    ;
+}
+class Class4 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class4
+    : self::Class4::field = #C2, super core::Object::•()
+    ;
+}
+
+constants  {
+  #C1 = <dynamic>[]
+  #C2 = self::Class2 {field:#C1}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///inferred_const_initializer.dart:
+- Class2. (from org-dartlang-testcase:///inferred_const_initializer.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.weak.outline.expect

@@ -0,0 +1,48 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:8:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class1() : field = []; // Error
+//                            ^
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:20:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class3() : field = Class2(); // Error
+//                            ^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class Class1 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class1
+    : self::Class1::field = <dynamic>[], super core::Object::•()
+    ;
+}
+class Class2 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class2
+    : self::Class2::field = const <dynamic>[], super core::Object::•()
+    ;
+}
+class Class3 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class3
+    : self::Class3::field = const self::Class2::•(), super core::Object::•()
+    ;
+}
+class Class4 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class4
+    : self::Class4::field = const self::Class2::•(), super core::Object::•()
+    ;
+}
+
+
+Extra constant evaluation status:
+Evaluated: ListLiteral @ org-dartlang-testcase:///inferred_const_initializer.dart:14:28 -> ListConstant(const <dynamic>[])
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///inferred_const_initializer.dart:20:28 -> InstanceConstant(const Class2{Class2.field: const <dynamic>[]})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///inferred_const_initializer.dart:26:34 -> InstanceConstant(const Class2{Class2.field: const <dynamic>[]})
+Extra constant evaluation: evaluated: 4, effectively constant: 3

pkg/front_end/testcases/general/constants/inferred_const_initializer.dart.weak.transformed.expect

@@ -0,0 +1,52 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:8:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class1() : field = []; // Error
+//                            ^
+//
+// pkg/front_end/testcases/general/constants/inferred_const_initializer.dart:20:28: Error: Constant expression expected.
+// Try inserting 'const'.
+//   const Class3() : field = Class2(); // Error
+//                            ^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class Class1 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class1
+    : self::Class1::field = core::_GrowableList::•<dynamic>(0), super core::Object::•()
+    ;
+}
+class Class2 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class2
+    : self::Class2::field = #C1, super core::Object::•()
+    ;
+}
+class Class3 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class3
+    : self::Class3::field = #C2, super core::Object::•()
+    ;
+}
+class Class4 extends core::Object /*hasConstConstructor*/  {
+  final field dynamic field;
+  const constructor •() → self::Class4
+    : self::Class4::field = #C2, super core::Object::•()
+    ;
+}
+
+constants  {
+  #C1 = <dynamic>[]
+  #C2 = self::Class2 {field:#C1}
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///inferred_const_initializer.dart:
+- Class2. (from org-dartlang-testcase:///inferred_const_initializer.dart:14:9)
+- Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart)