Fix type substitution of "star" types.
When performing type substitution, there are three types involved, the
substitution site (`this` in TypeImpl.substitute2), the type we are
replacing (`parameterType` in TypeImpl.substitute2), and the
replacement type (`argumentType` in TypeImpl.substitute2).
Previously, we only handled the nullabilities of `this` and
`argumentType`. This CL adds support for the possibility that
`parameterType` might have nullability "*". This happens because
TypeParameterElement.type returns a star type, so for instance when
subsituting `int` for `T` in `List<T>` to form `List<int>`, we are
actually substituting `int` for `T*` in `List<T*>`.
Change-Id: I0a61fdc47ec8aa205dc0c539c49ea7799ed4ac05
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103542
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/dart/element/type.dart b/pkg/analyzer/lib/src/dart/element/type.dart
index 12550dc..f8e0113 100644
--- a/pkg/analyzer/lib/src/dart/element/type.dart
+++ b/pkg/analyzer/lib/src/dart/element/type.dart
@@ -3244,7 +3244,8 @@
[List<FunctionTypeAliasElement> prune]) {
int length = parameterTypes.length;
for (int i = 0; i < length; i++) {
- if (parameterTypes[i] == this) {
+ var parameterType = parameterTypes[i];
+ if (parameterType is TypeParameterTypeImpl && parameterType == this) {
TypeImpl argumentType = argumentTypes[i];
// TODO(scheglov) It should not happen, but sometimes arguments are null.
@@ -3254,15 +3255,29 @@
// TODO(scheglov) Proposed substitution rules for nullability.
NullabilitySuffix resultNullability;
+ NullabilitySuffix parameterNullability =
+ parameterType.nullabilitySuffix;
NullabilitySuffix argumentNullability = argumentType.nullabilitySuffix;
- if (argumentNullability == NullabilitySuffix.question ||
- nullabilitySuffix == NullabilitySuffix.question) {
- resultNullability = NullabilitySuffix.question;
- } else if (argumentNullability == NullabilitySuffix.star ||
- nullabilitySuffix == NullabilitySuffix.star) {
- resultNullability = NullabilitySuffix.star;
+ if (parameterNullability == NullabilitySuffix.none) {
+ if (argumentNullability == NullabilitySuffix.question ||
+ nullabilitySuffix == NullabilitySuffix.question) {
+ resultNullability = NullabilitySuffix.question;
+ } else if (argumentNullability == NullabilitySuffix.star ||
+ nullabilitySuffix == NullabilitySuffix.star) {
+ resultNullability = NullabilitySuffix.star;
+ } else {
+ resultNullability = NullabilitySuffix.none;
+ }
+ } else if (parameterNullability == NullabilitySuffix.star) {
+ if (argumentNullability == NullabilitySuffix.question ||
+ nullabilitySuffix == NullabilitySuffix.question) {
+ resultNullability = NullabilitySuffix.question;
+ } else {
+ resultNullability = argumentNullability;
+ }
} else {
- resultNullability = NullabilitySuffix.none;
+ // We should never be substituting for `T?`.
+ throw new StateError('Tried to substitute for T?');
}
return argumentType.withNullability(resultNullability);
diff --git a/pkg/analyzer/test/src/diagnostics/default_list_constructor_mismatch_test.dart b/pkg/analyzer/test/src/diagnostics/default_list_constructor_mismatch_test.dart
index 1769170..30e9267 100644
--- a/pkg/analyzer/test/src/diagnostics/default_list_constructor_mismatch_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/default_list_constructor_mismatch_test.dart
@@ -36,10 +36,7 @@
''');
}
- @failingTest
test_inferredType() async {
- // This test is failing because summary support is incomplete, which results
- // in the constructor having a type of 'List<C*>*'.
await assertErrorsInCode('''
class C {}
List<C> v = List(5);
@@ -48,16 +45,6 @@
]);
}
- test_starType() async {
- // TODO(brianwilkerson) This test is currently taking advantage of the fact
- // that the SDK is not opted in, which makes the use of `int` below a
- // reference to 'int*'. When it's possible to opt-out in a test this needs
- // to be updated to use an explicitly opted out type.
- await assertNoErrorsInCode('''
-List<int> v = List(5);
-''');
- }
-
test_typeParameter() async {
await assertErrorsInCode('''
class C<T> {
