Fix #9115: Make Java-defined fields effectively final #9126
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smarter
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…d is present In scala#9126, Java fields were marked effectively finals to prevent false overrides. This poses a problem when a Java field and method of the same name are present, because a Scala val or def will match both of these according to Denotation#matches. We could tweak `matches` further to not consider the Java field to match any Scala definition, but that might introduce new problems (we couldn't trust `FullMatch` anymore and would need to check the info of any Java symbol which might cause cycles, we would also probably need to tweak overloading resolution to avoid ambiguity when trying to decide whether to select the Java field or the Scala override of the Java method). This commit takes a different approach: we allow a val or def to match a Java field, but we tweak the logic that checks whether the `override` modifier is correctly used to disallow definitions that _only_ match a Java field (thus preventing tests/neg/i9115 from compiling), while letting through definitions that both match a Java field and something else (thus making tests/pos/i9392 compile). This is all a bit messy but I can't think of a better solution which wouldn't be significantly more complicated.
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…d is present In scala#9126, Java fields were marked effectively finals to prevent false overrides. This poses a problem when a Java field and method of the same name are present, because a Scala val or def will match both of these according to Denotation#matches. This commit changes `matches` to prevent Java field from matching any Scala method, but we can't prevent them from matching Scala definitions with NotAMethod signature without introducing more complexity, so the following still doesn't compile unlike Scala 2: ```java package pkg; public class J { int i = 0; public int i() { return 1; } } ``` ```scala class S2 extends pkg.J { override def i: Int = 2 // error } ``` I have an alternative fix at scala#9412 which doesn't have this issue but is more hacky.
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…d is present In scala#9126, Java fields were marked effectively finals to prevent false overrides. This poses a problem when a Java field and method of the same name are present, because a Scala val or def will match both of these according to Denotation#matches. This commit changes `matches` to prevent Java field from matching any Scala method, but we can't prevent them from matching Scala definitions with NotAMethod signature without introducing more complexity, so the following still doesn't compile unlike Scala 2: ```java package pkg; public class J { int i = 0; public int i() { return 1; } } ``` ```scala class S2 extends pkg.J { override def i: Int = 2 // error } ``` I have an alternative fix at scala#9412 which doesn't have this issue but is more hacky.
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