RFR: JDK-8214113: Switch expressions may have constant type and may be skipped during write (original) (raw)

Jan Lahoda jan.lahoda at oracle.com
Wed Nov 21 12:41:27 UTC 2018


Hi,

Consider switch expression produces only a single constant value, like: switch (expr) { default: counter++; break 1; }

Then Attr.condType returns the type of the given constant value, and if that is a constant type, the type of the whole switch expression is a constant type. And Gen may then elide the whole switch expression, which is wrong, as it may contain side-effects, or all the other arms may the throwing an exception.

The solution would be to simply call .baseType() on the result, but simply deleting the special case for a single output value should work as well, as the following condition should handle the single output value case well.

Bug: https://bugs.openjdk.java.net/browse/JDK-8214113 Webrev: http://cr.openjdk.java.net/~jlahoda/8214113/webrev.00/

How does this look?

Thanks, Jan



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