Fix #12572: Ignore default accessor bridges in non-native JS classes. #12657
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…sses. They are not emitted, and they are excluded when looking up the default getter to call.
| * because they call another default accessor, making their entire body an | ||
| * <undefined-param> that cannot be eliminated. |
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What's <undefined-param> ? I see the test cases set the default value to = js.undefined but what if I use a different default value?
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The right-hand-side of a default value is irrelevant. As soon as there is a default value, where = js.undefined, = 42 or = js.native, that parameter will be an <undefined-param>. <undefined-param>'s are markers that are always eliminated at compile-time, and replaced by no argument (because you can do that in JS). That is done at
https://github.com/lampepfl/dotty/blob/0d1d47a8fde5226b81376f5ff09512be17abaa0c/compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala#L3764-L3776
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Ah, so should the compiler disallow a default value that is not exactly js.undefined ?
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No, it shouldn't. It wouldn't work when the type of the parameter is Int, for example. Also, an actual value can have valuable documentation purposes. It's been allowed for 8 years in Scala.js for Scala 2, so we can't change that.
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They are not emitted, and they are excluded when looking up the default getter to call.
Who would like to review this? Anyone familiar with default getters?