Fix #2888: Avoid caching supertypes of hk apps with provisional infos #2889
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…isional infos If the type constructor of a hk application has a provisional info (because we are starting to initialize an F-bounded definition), we cannot cache its supertype. We get an empty bound if we do.
smarter
requested changes
Jul 19, 2017
| @@ -3012,12 +3012,16 @@ object Types { | |||
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| override def superType(implicit ctx: Context): Type = { | |||
| if (ctx.period != validSuper) { | |||
| var canCache = true | |||
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This variable appears to be set but never read.
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Also this is missing the testcase from #2888 |
smarter
reviewed
Jul 19, 2017
| @@ -3012,15 +3012,19 @@ object Types { | |||
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| override def superType(implicit ctx: Context): Type = { | |||
| if (ctx.period != validSuper) { | |||
| var canCache = true | |||
| cachedSuper = tycon match { | |||
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Modifying cachedSuper when we cannot cache the value seems dangerous. If validSuper refers to a non-empty period, then a subsequent call to superType might be done with ctx.period equal to validSuper and would return the new, incorrect value in cachedSuper.
smarter
approved these changes
Jul 19, 2017
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If the type constructor of a hk application has a provisional info (because
we are starting to initialize an F-bounded definition), we cannot cache its
supertype. We get an empty bound if we do.