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[cfe] Handle NullCheck in constant evaluation
Closes #42802 Closes #42803 Change-Id: I282539cbfef90309dd343950101aefe0820785b7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155600 Reviewed-by: Johnni Winther <[email protected]>
1 parent 40fd1c4 commit b8dc762

15 files changed

+325
-5
lines changed

‎pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

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@@ -1308,6 +1308,14 @@ Message _withArgumentsConstEvalNonConstantVariableGet(String string) {
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arguments: {'string': string});
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}
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// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
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const Code<Null> codeConstEvalNonNull = messageConstEvalNonNull;
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// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
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const MessageCode messageConstEvalNonNull = const MessageCode(
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"ConstEvalNonNull",
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message: r"""Constant expression must be non-null.""");
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// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
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const Code<Null> codeConstEvalNotListOrSetInSpread =
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messageConstEvalNotListOrSetInSpread;

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

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@@ -42,6 +42,7 @@ import '../fasta_codes.dart'
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messageConstEvalFailedAssertion,
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messageConstEvalNotListOrSetInSpread,
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messageConstEvalNotMapInSpread,
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messageConstEvalNonNull,
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messageConstEvalNullValue,
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messageConstEvalStartingPoint,
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messageConstEvalUnevaluated,
@@ -2238,6 +2239,18 @@ class ConstantEvaluator extends RecursiveVisitor<Constant> {
22382239
isNonNullableByDefault));
22392240
}
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@override
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Constant visitNullCheck(NullCheck node) {
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final Constant constant = _evaluateSubexpression(node.operand);
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if (constant is NullConstant) {
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return report(node, messageConstEvalNonNull);
2247+
}
2248+
if (shouldBeUnevaluated) {
2249+
return unevaluated(node, new NullCheck(extract(constant)));
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}
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return constant;
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}
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@override
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Constant visitSymbolLiteral(SymbolLiteral node) {
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final Reference libraryReference =

‎pkg/front_end/messages.status

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@@ -122,6 +122,8 @@ ConstEvalNegativeShift/example: Fail
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ConstEvalNonConstantVariableGet/example: Fail
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ConstEvalNotListOrSetInSpread/example: Fail
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ConstEvalNotMapInSpread/example: Fail
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ConstEvalNonNull/analyzerCode: Fail
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ConstEvalNonNull/example: Fail
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ConstEvalNullValue/example: Fail
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ConstEvalStartingPoint/analyzerCode: Fail # This is just used for displaying the starting point.
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ConstEvalStartingPoint/example: Fail # This is just used for displaying the starting point.

‎pkg/front_end/messages.yaml

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@@ -132,6 +132,9 @@ ConstEvalNegativeShift:
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ConstEvalTruncateError:
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template: "Binary operator '#string ~/ #string2' results is Infinity or NaN."
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ConstEvalNonNull:
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template: "Constant expression must be non-null."
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ConstEvalInvalidMethodInvocation:
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template: "The method '#string' can't be invoked on '#constant' in a constant expression."
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analyzerCode: UNDEFINED_OPERATOR

‎pkg/front_end/testcases/incremental_initialize_from_dill/flutter_widget_transform_nnbd.yaml

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@@ -64,8 +64,7 @@ worlds:
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{
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"name": "flutter",
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"rootUri": "../flutter",
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"packageUri": "lib/",
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"languageVersion": "2.9"
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"packageUri": "lib/"
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}
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]
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}

‎pkg/front_end/testcases/incremental_initialize_from_dill/flutter_widget_transform_nnbd.yaml.world.2.expect

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@@ -47,8 +47,14 @@ library from "org-dartlang-test:///main.dart" as main {
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import "org-dartlang-test:///foo.dart";
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static field foo::Foo foo = invalid-expression "Constant evaluation has no support for NullCheck!";
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static field foo::Foo foo = #C7;
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}
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constants {
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#C1 = null
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#C2 = "org-dartlang-test:///main.dart"
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#C3 = 3.0
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#C4 = 17.0
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#C5 = <wid::_Location*>[]
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#C6 = wid::_Location {file:#C2, line:#C3, column:#C4, name:#C1, parameterLocations:#C5}
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#C7 = foo::Foo {_location:#C6}
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}

‎pkg/front_end/testcases/incremental_initialize_from_dill/flutter_widget_transformer_non_const.yaml

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@@ -59,8 +59,7 @@ worlds:
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{
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"name": "flutter",
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"rootUri": "../flutter",
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"packageUri": "lib/",
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"languageVersion": "2.9"
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"packageUri": "lib/"
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}
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]
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}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart

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// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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const int? a = 42;
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const int b = a!;
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const int? c = null;
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const int? d = c!;
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class Class {
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final int y;
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const Class(int? x) : y = x!;
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}
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const Class e = const Class(a);
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const Class f = const Class(c);
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main() {
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expect(42, a);
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expect(42, b);
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expect(42, e.y);
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}
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expect(expected, actual) {
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if (expected != actual) throw 'Expected $expected, actual $actual';
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}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.outline.expect

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library /*isNonNullableByDefault*/;
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import self as self;
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import "dart:core" as core;
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class Class extends core::Object /*hasConstConstructor*/ {
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final field core::int y;
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const constructor •(core::int? x) → self::Class
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: self::Class::y = x!, super core::Object::•()
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;
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}
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static const field core::int? a = 42;
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static const field core::int b = self::a!;
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static const field core::int? c = null;
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static const field core::int? d = self::c!;
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static const field self::Class e = const self::Class::•(self::a);
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static const field self::Class f = const self::Class::•(self::c);
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static method main() → dynamic
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;
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static method expect(dynamic expected, dynamic actual) → dynamic
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;

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.strong.expect

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//
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// Problems in component:
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Error: Constant evaluation error:
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// const int? d = c!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Context: Constant expression must be non-null.
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// const int? d = c!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:12: Context: While analyzing:
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// const int? d = c!;
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// ^
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:23: Error: Constant evaluation error:
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// const Class f = const Class(c);
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:13:30: Context: Constant expression must be non-null.
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// const Class(int? x) : y = x!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:13: Context: While analyzing:
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// const Class f = const Class(c);
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// ^
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//
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library /*isNonNullableByDefault*/;
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import self as self;
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import "dart:core" as core;
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class Class extends core::Object /*hasConstConstructor*/ {
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final field core::int y;
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const constructor •(core::int? x) → self::Class
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: self::Class::y = x!, super core::Object::•()
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;
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}
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static const field core::int? a = #C1;
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static const field core::int b = #C1;
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static const field core::int? c = #C2;
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static const field core::int? d = invalid-expression "Constant expression must be non-null.";
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static const field self::Class e = #C3;
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static const field self::Class f = invalid-expression "Constant expression must be non-null.";
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static method main() → dynamic {
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self::expect(42, #C1);
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self::expect(42, #C1);
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self::expect(42, (#C3).{self::Class::y});
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}
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static method expect(dynamic expected, dynamic actual) → dynamic {
46+
if(!expected.{core::Object::==}(actual))
47+
throw "Expected ${expected}, actual ${actual}";
48+
}
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constants {
51+
#C1 = 42
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#C2 = null
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#C3 = self::Class {y:#C1}
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}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.strong.transformed.expect

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//
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// Problems in component:
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Error: Constant evaluation error:
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// const int? d = c!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Context: Constant expression must be non-null.
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// const int? d = c!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:12: Context: While analyzing:
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// const int? d = c!;
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// ^
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:23: Error: Constant evaluation error:
15+
// const Class f = const Class(c);
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:13:30: Context: Constant expression must be non-null.
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// const Class(int? x) : y = x!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:13: Context: While analyzing:
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// const Class f = const Class(c);
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// ^
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//
24+
library /*isNonNullableByDefault*/;
25+
import self as self;
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import "dart:core" as core;
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class Class extends core::Object /*hasConstConstructor*/ {
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final field core::int y;
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const constructor •(core::int? x) → self::Class
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: self::Class::y = x!, super core::Object::•()
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;
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}
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static const field core::int? a = #C1;
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static const field core::int b = #C1;
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static const field core::int? c = #C2;
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static const field core::int? d = invalid-expression "Constant expression must be non-null.";
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static const field self::Class e = #C3;
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static const field self::Class f = invalid-expression "Constant expression must be non-null.";
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static method main() → dynamic {
41+
self::expect(42, #C1);
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self::expect(42, #C1);
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self::expect(42, (#C3).{self::Class::y});
44+
}
45+
static method expect(dynamic expected, dynamic actual) → dynamic {
46+
if(!expected.{core::Object::==}(actual))
47+
throw "Expected ${expected}, actual ${actual}";
48+
}
49+
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constants {
51+
#C1 = 42
52+
#C2 = null
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#C3 = self::Class {y:#C1}
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}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.textual_outline.expect

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const int? a = 42;
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const int b = a!;
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const int? c = null;
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const int? d = c!;
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6+
class Class {
7+
final int y;
8+
const Class(int? x) : y = x!;
9+
}
10+
11+
const Class e = const Class(a);
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const Class f = const Class(c);
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main() {}
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expect(expected, actual) {}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.textual_outline_modelled.expect

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class Class {
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const Class(int? x) : y = x!;
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final int y;
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}
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const Class e = const Class(a);
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const Class f = const Class(c);
8+
const int b = a!;
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const int? a = 42;
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const int? c = null;
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const int? d = c!;
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expect(expected, actual) {}
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main() {}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.weak.expect

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//
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// Problems in component:
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Error: Constant evaluation error:
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// const int? d = c!;
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// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Context: Constant expression must be non-null.
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// const int? d = c!;
9+
// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:12: Context: While analyzing:
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// const int? d = c!;
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// ^
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//
14+
// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:23: Error: Constant evaluation error:
15+
// const Class f = const Class(c);
16+
// ^
17+
// pkg/front_end/testcases/nnbd/constant_null_check.dart:13:30: Context: Constant expression must be non-null.
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// const Class(int? x) : y = x!;
19+
// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:13: Context: While analyzing:
21+
// const Class f = const Class(c);
22+
// ^
23+
//
24+
library /*isNonNullableByDefault*/;
25+
import self as self;
26+
import "dart:core" as core;
27+
28+
class Class extends core::Object /*hasConstConstructor*/ {
29+
final field core::int y;
30+
const constructor •(core::int? x) → self::Class
31+
: self::Class::y = x!, super core::Object::•()
32+
;
33+
}
34+
static const field core::int? a = #C1;
35+
static const field core::int b = #C1;
36+
static const field core::int? c = #C2;
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static const field core::int? d = invalid-expression "Constant expression must be non-null.";
38+
static const field self::Class e = #C3;
39+
static const field self::Class f = invalid-expression "Constant expression must be non-null.";
40+
static method main() → dynamic {
41+
self::expect(42, #C1);
42+
self::expect(42, #C1);
43+
self::expect(42, (#C3).{self::Class::y});
44+
}
45+
static method expect(dynamic expected, dynamic actual) → dynamic {
46+
if(!expected.{core::Object::==}(actual))
47+
throw "Expected ${expected}, actual ${actual}";
48+
}
49+
50+
constants {
51+
#C1 = 42
52+
#C2 = null
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#C3 = self::Class {y:#C1}
54+
}

‎pkg/front_end/testcases/nnbd/constant_null_check.dart.weak.transformed.expect

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//
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// Problems in component:
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//
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Error: Constant evaluation error:
5+
// const int? d = c!;
6+
// ^
7+
// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:17: Context: Constant expression must be non-null.
8+
// const int? d = c!;
9+
// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:9:12: Context: While analyzing:
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// const int? d = c!;
12+
// ^
13+
//
14+
// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:23: Error: Constant evaluation error:
15+
// const Class f = const Class(c);
16+
// ^
17+
// pkg/front_end/testcases/nnbd/constant_null_check.dart:13:30: Context: Constant expression must be non-null.
18+
// const Class(int? x) : y = x!;
19+
// ^
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// pkg/front_end/testcases/nnbd/constant_null_check.dart:17:13: Context: While analyzing:
21+
// const Class f = const Class(c);
22+
// ^
23+
//
24+
library /*isNonNullableByDefault*/;
25+
import self as self;
26+
import "dart:core" as core;
27+
28+
class Class extends core::Object /*hasConstConstructor*/ {
29+
final field core::int y;
30+
const constructor •(core::int? x) → self::Class
31+
: self::Class::y = x!, super core::Object::•()
32+
;
33+
}
34+
static const field core::int? a = #C1;
35+
static const field core::int b = #C1;
36+
static const field core::int? c = #C2;
37+
static const field core::int? d = invalid-expression "Constant expression must be non-null.";
38+
static const field self::Class e = #C3;
39+
static const field self::Class f = invalid-expression "Constant expression must be non-null.";
40+
static method main() → dynamic {
41+
self::expect(42, #C1);
42+
self::expect(42, #C1);
43+
self::expect(42, (#C3).{self::Class::y});
44+
}
45+
static method expect(dynamic expected, dynamic actual) → dynamic {
46+
if(!expected.{core::Object::==}(actual))
47+
throw "Expected ${expected}, actual ${actual}";
48+
}
49+
50+
constants {
51+
#C1 = 42
52+
#C2 = null
53+
#C3 = self::Class {y:#C1}
54+
}

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