Deprecate ElementAnnotation.constantValue

R=brianwilkerson@google.com, pquitslund@google.com

Change-Id: Ifae6a614c20b703d9614d7ccc2f8b254bafcb070
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/160942
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/CHANGELOG.md

@@ -2,6 +2,8 @@
 * Added `LocalVariableElement.hasInitializer`,
   `PropertyInducingElement.hasInitializer`, `ParameterElement.hasDefaultValue`.
 * `ElementImpl.toString()` uses `getDisplayString(withNullability: true)`.
+* Deprecated `ElementAnnotation.constantValue`, it does not guarantee that
+  the value has been computed. Use `computeConstantValue()` instead.
 
 ## 0.40.0
 * Added `LibraryElement.featureSet`.

pkg/analyzer/lib/dart/element/element.dart

@@ -691,6 +691,7 @@ abstract class ElementAnnotation implements ConstantEvaluationTarget {
   /// Return a representation of the value of this annotation, or `null` if the
   /// value of this annotation has not been computed or if the value could not
   /// be computed because of errors.
+  @Deprecated('Use computeConstantValue() instead')
   DartObject get constantValue;
 
   /// Return the element representing the field, variable, or const constructor

pkg/analyzer/lib/src/dart/element/element.dart

@@ -2409,6 +2409,7 @@ class ElementAnnotationImpl implements ElementAnnotation {
   List<AnalysisError> get constantEvaluationErrors =>
       evaluationResult?.errors ?? const <AnalysisError>[];
 
+  @Deprecated('Use computeConstantValue() instead')
   @override
   DartObject get constantValue => evaluationResult?.value;
 
@@ -2565,7 +2566,7 @@ class ElementAnnotationImpl implements ElementAnnotation {
       computeConstants(library.typeProvider, library.typeSystem,
           context.declaredVariables, [this], analysisOptions.experimentStatus);
     }
-    return constantValue;
+    return evaluationResult?.value;
   }
 
   @override
@@ -7596,6 +7597,7 @@ abstract class VariableElementImpl extends ElementImpl
   /// initializers.
   Expression get constantInitializer => null;
 
+  @Deprecated('Use computeConstantValue() instead')
   @override
   DartObject get constantValue => evaluationResult?.value;
 

pkg/analyzer/lib/src/error/best_practices_verifier.dart

@@ -1480,7 +1480,7 @@ class BestPracticesVerifier extends RecursiveAstVisitor<void> {
     }
     for (var annotation in classElement.metadata) {
       if (annotation.isTarget) {
-        var value = annotation.constantValue;
+        var value = annotation.computeConstantValue();
         var kinds = <TargetKind>{};
         for (var kindObject in value.getField('kinds').toSetValue()) {
           var index = kindObject.getField('index').toIntValue();

pkg/analyzer/test/src/dart/analysis/driver_test.dart

@@ -860,7 +860,7 @@ const x = 1;
 ''');
     var result = await driver.getResult(testFile);
     Annotation at_x = AstFinder.getClass(result.unit, 'C').metadata[0];
-    expect(at_x.elementAnnotation.constantValue.toIntValue(), 1);
+    expect(at_x.elementAnnotation.computeConstantValue().toIntValue(), 1);
   }
 
   test_const_circular_reference() async {

pkg/analyzer/test/src/dart/element/element_test.dart

@@ -858,12 +858,10 @@ main() {
     ParameterElement parameter = argument.staticParameterElement;
 
     ElementAnnotation annotation = parameter.metadata[0];
-    expect(annotation.constantValue, isNull);
 
     DartObject value = annotation.computeConstantValue();
     expect(value, isNotNull);
     expect(value.getField('f').toStringValue(), 'x');
-    expect(annotation.constantValue, value);
   }
 }
 

pkg/analyzer/test/src/dart/resolution/constant_test.dart

@@ -40,7 +40,7 @@ const a = const A();
     // To evaluate `const A()` we have to evaluate `{int p}`.
     // Even if its value is `null`.
     expect(p.isConstantEvaluated, isTrue);
-    expect(p.constantValue.isNull, isTrue);
+    expect(p.computeConstantValue().isNull, isTrue);
   }
 
   test_constFactoryRedirection_super() async {
@@ -64,7 +64,7 @@ main() {}
 ''');
 
     var node = findNode.annotation('@I');
-    var value = node.elementAnnotation.constantValue;
+    var value = node.elementAnnotation.computeConstantValue();
     expect(value.getField('(super)').getField('f').toIntValue(), 42);
   }