[dart2js] Fix type inference for record accessses on invalid indices.
Bug: 52438
Change-Id: Ic180e181142f6a33e9915f13890d9a3825a5ec0c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/304380
Commit-Queue: Nate Biggs <natebiggs@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
diff --git a/pkg/compiler/lib/src/inferrer/typemasks/masks.dart b/pkg/compiler/lib/src/inferrer/typemasks/masks.dart
index 13327c0..d1c39be 100644
--- a/pkg/compiler/lib/src/inferrer/typemasks/masks.dart
+++ b/pkg/compiler/lib/src/inferrer/typemasks/masks.dart
@@ -917,10 +917,15 @@
@override
AbstractValue getGetterTypeInRecord(AbstractValue value, String getterName) {
- final type = value is RecordTypeMask
- ? value.types[value.shape.indexOfGetterName(getterName)]
- : null;
- return type ?? dynamicType;
+ if (value is RecordTypeMask) {
+ final getterIndex = value.shape.indexOfGetterName(getterName);
+ // Generated code can sometimes contain record accesses for invalid
+ // getters.
+ if (getterIndex >= 0) {
+ return value.types[getterIndex];
+ }
+ }
+ return dynamicType;
}
@override
diff --git a/tests/web/regress/issue/52438_test.dart b/tests/web/regress/issue/52438_test.dart
new file mode 100644
index 0000000..4ea98cc
--- /dev/null
+++ b/tests/web/regress/issue/52438_test.dart
@@ -0,0 +1,15 @@
+// Copyright (c) 2023, 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.
+
+// Switches geenrate record accesses on non-existent fields. These accesses
+// should be guarded by a type check but Dart2JS does not always promote
+// correctly after the type check.
+
+void main() {
+ Object r = (1, 2);
+ switch (r) {
+ case (int _, int _, int c):
+ print('Skip, no match');
+ }
+}
