On Thu, 15 Jan 2026 09:50:23 GMT, Maurizio Cimadamore <[email protected]>
wrote:
>> Adding use site null checks for method invocations. They are added by
>> default but if option: `noUseSiteNullChecks` is passed, the compiler won't
>> generate them
>
> src/jdk.compiler/share/classes/com/sun/tools/javac/comp/NullChecksWriter.java
> line 204:
>
>> 202: }
>> 203: Type formalArgType = declaredArgTypes.head;
>> 204: if (msym.isVarArgs() && formalArgType == varArgsArg) {
>
> I think this check can misfire. Some types are shared -- e.g.
> syms.stringType, so you might get `==` in "wrong" places. That said, here
> `varArgsArg` is an array type, and for that we might always get a fresh
> instance... so it might work.
>
> It also looks like there might be a potential problem here -- this code runs
> _after_ varargs translation has occurred. Meaning that for varargs, we only
> see a javac-created array and we can check the variadic elements.
>
> But again, the plan here would be to disallow `C!...` so this is ok.
Question, now that I read through all the code... I wonder if we could do this
more simply:
* take the list of actual arguments
* skip the first P prefix arguments
* drop the last variadic array (if the method is variadic)
* then do a loop and check what remains against the "source-like" formal types
-------------
PR Review Comment:
https://git.openjdk.org/valhalla/pull/1910#discussion_r2693704826
