RFR: 5038439: Warning message for literal shift amounts outside the canonical domain [v3]

[Archie Cobbs]

On Wed, 5 Nov 2025 15:14:49 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

>> Having two assignments should not be a blocker for `->`, no? It ought to be enough to use `{}`:
>> 
>>             switch (((OperatorSymbol)operator).opcode) {
>>             case ByteCodes.ishl, ByteCodes.ishr, ByteCodes.iushr,
>>                  ByteCodes.ishll, ByteCodes.ishrl, ByteCodes.iushrl -> {
>>                 targetType = syms.intType;
>>                 maximumShift = 32;
>>             }
>>             case ByteCodes.lshl, ByteCodes.lshr, ByteCodes.lushr,
>>                  ByteCodes.lshll, ByteCodes.lshrl, ByteCodes.lushrl -> {
>>                 targetType = syms.longType;
>>                 maximumShift = 64;
>>             }
>>             default -> {
>>                 return;
>>             }
>>             }
>> 
>> 
>> I am not strictly insisting on using `->`, but it generally makes things simpler as there's guaranteed no fallthrough.
>
> The `->` can be used, even when having general statements/multiple assignments/etc. - just wrap the code with `{}`, no?
> 
> 
>             switch (((OperatorSymbol)operator).opcode) {
>             case ByteCodes.ishl, ByteCodes.ishr, ByteCodes.iushr,
>                  ByteCodes.ishll, ByteCodes.ishrl, ByteCodes.iushrl -> {
>                 targetType = syms.intType;
>                 maximumShift = 32;
>             }
>             case ByteCodes.lshl, ByteCodes.lshr, ByteCodes.lushr,
>                  ByteCodes.lshll, ByteCodes.lshrl, ByteCodes.lushrl -> {
>                 targetType = syms.longType;
>                 maximumShift = 64;
>             }
>             default -> {
>                 return;
>             }
>             }
> 
> 
> I am not strictly insisting on using `->` but it is typically easier to reason about switches that are guaranteed to not have fallthrough.

> Having two assignments should not be a blocker for `->`, no? It ought to be enough to use `{}`:

Duh - of course you're right. Fixed in 89fe2fb1f93.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27102#discussion_r2495043399