Compute constant dependencies for constructor elements in canBeConst().

scheglov · commit-bot@chromium.org · commit 2246f0a8a36f · 2019-09-06T03:29:28.000Z
R=brianwilkerson@google.com, pquitslund@google.com Change-Id: I92871e880e669aca5447f6fe7d7a8249421e7c44 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115613 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -2786,6 +2786,16 @@ class ConstructorElementImpl extends ExecutableElementImpl
     appendToWithName(buffer, name);
   }
 
+  /// Ensures that dependencies of this constructor, such as default values
+  /// of formal parameters, are evaluated.
+  void computeConstantDependencies() {
+    if (!isConstantEvaluated) {
+      AnalysisOptionsImpl analysisOptions = context.analysisOptions;
+      computeConstants(context.typeProvider, context.typeSystem,
+          context.declaredVariables, [this], analysisOptions.experimentStatus);
+    }
+  }
+
   @deprecated
   @override
   ConstructorDeclaration computeNode() =>
diff --git a/pkg/analyzer/lib/src/lint/linter.dart b/pkg/analyzer/lib/src/lint/linter.dart
@@ -15,7 +15,9 @@ import 'package:analyzer/file_system/file_system.dart' as file_system;
 import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/dart/constant/potentially_constant.dart';
+import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/inheritance_manager3.dart';
+import 'package:analyzer/src/dart/element/member.dart';
 import 'package:analyzer/src/dart/error/lint_codes.dart';
 import 'package:analyzer/src/generated/engine.dart'
     show AnalysisErrorInfo, AnalysisErrorInfoImpl, AnalysisOptions, Logger;
@@ -280,6 +282,14 @@ class LinterContextImpl implements LinterContext {
     if (element == null || !element.isConst) {
       return false;
     }
+
+    // Ensure that dependencies (e.g. default parameter values) are computed.
+    var implElement = element;
+    if (element is ConstructorMember) {
+      implElement = element.baseElement;
+    }
+    (implElement as ConstructorElementImpl).computeConstantDependencies();
+
     //
     // Verify that the evaluation of the constructor would not produce an
     // exception.
diff --git a/pkg/analyzer/test/src/lint/linter/linter_context_impl_test.dart b/pkg/analyzer/test/src/lint/linter/linter_context_impl_test.dart
@@ -206,4 +206,20 @@ A f() => A([1, 2, 3]);
 ''');
     assertCanBeConst("A([", true);
   }
+
+  void test_true_importedClass_defaultValue() async {
+    var aPath = convertPath('/test/lib/a.dart');
+    newFile(aPath, content: r'''
+class A {
+  final int a;
+  const A({int b = 1}) : a = b * 2;
+}
+''');
+    await resolve('''
+import 'a.dart';
+
+A f() => A();
+''');
+    assertCanBeConst("A();", true);
+  }
 }
