MutableCallSite does not work?

[xuwei-k]

No description provided.

[alexp-sssup]

Hi, thanks for getting in touch. Can you provide an example demonstrating the problem?

MethodHandles are supported in general, so there must be a specific corner case that is not handled correctly.

With an example we will be able to identify and fix the problem.

[xuwei-k]

Sorry, I misunderstood. Maybe not MethodHandle but java.lang.invoke.SwitchPoint does not work.

https://javafiddle.leaningtech.com/N4IgLglmA2CmIC4QgDQgK4AcAmBDMs2iIATAAwkCsAtGQIy0AcAKiSQpWQnWQHSN06ALVQgAZhDgBnRAG1QmfAAtiAWVwQAdrwBWuAG65RAYwD2mgheKLjAa1wBzWAAJYAD1wBbTHADcAHU1AiG9TACcwZz1DXmhcTQdeLX1TW1heVVgwJVNsAAl47D9g0Iiog1xY+MTk1PTM7NyCzSLYKQDNEMxwyOjKuISkzRS0jKyc7GYAT0xYDq6e8piBmuG63gBlAHcoYyUABVMtMA7AzHQAI2gIY2djOKkpZ3UtZ2BA50-nc6ub5ykwPg-ikINhnJ4NJoABQbMBhLQOWQAXWcuDCDikAEpnNkwqYtk9mEo8VtcFcXO9NF9qc9xk1CnBnnkAPoAsLGfDOAC8tMa+QZbViplSWChmN4EhaADUIBF0LhoDC4QjePdcI8UM5-CAzJoOWBtZqGhNprNeJ46ZMZrAlfDBmqNc5YXbEg6sZiOjSvttdgcjhZ-phIjzNLAtk6dmA9odjmLPV7UY9YBEoQBCKRB3hKdUAIVgsE0AElhgrQfhCGKPR8E8b6S1GVtwmkwnRuUzWXD9fGvbX+fWXI2ws2SG3e81WlJeLMwp50AQAILo9AWixSKGqFls-VGzed-C8MDWsWauiashVqk1y3jhtN5NtjNgXgOeVhbAAdSgSmYbTAUMHzans4AHJiQF4Jk6UwArAni8KYc5TnaMDQiBYTgV8AC+gRYZoIAYUiGFAA

https://github.com/openjdk/jdk/blob/jdk8-b120/jdk/src/share/classes/java/lang/invoke/SwitchPoint.java#L59-L66

https://docs.oracle.com/javase/8/docs/api/java/lang/invoke/SwitchPoint.html

package example;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.invoke.SwitchPoint;

public class Main {
    public static void main(String[] args) throws Throwable {
        MethodHandle MH_strcat = MethodHandles.lookup().findVirtual(String.class, "concat", MethodType.methodType(String.class, String.class));
        SwitchPoint spt = new SwitchPoint();
        assert(!spt.hasBeenInvalidated());
        MethodHandle worker1 = MH_strcat;
        MethodHandle worker2 = MethodHandles.permuteArguments(MH_strcat, MH_strcat.type(), 1, 0);
        MethodHandle worker = spt.guardWithTest(worker1, worker2);
        System.out.println(worker);
    }
}

[alexp-sssup]

I can't reproduce this problem, can you please try again with a recent nightly build?

https://cjrtnc.leaningtech.com/3_20241216_574/cj3loader.js

[xuwei-k]

please try again with a recent nightly build?

SwitchPoint works with nightly build. thanks!

I have another similar problem. (sorry for in succession)

MutableCallSite does not work 🤔

https://github.com/openjdk/jdk/blob/9a9add8825a040565051a09010b29b099c2e7d49/jdk/src/share/classes/java/lang/invoke/MutableCallSite.java#L42-L49

package example;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.invoke.MutableCallSite;

public class Main {
    public static void main(String[] args) throws Throwable {
        MutableCallSite name = new MutableCallSite(MethodType.methodType(String.class));
        MethodHandle MH_name = name.dynamicInvoker();
        MethodType MT_str1 = MethodType.methodType(String.class);
        MethodHandle MH_upcase = MethodHandles.lookup().findVirtual(String.class, "toUpperCase", MT_str1);
        MethodHandle worker1 = MethodHandles.filterReturnValue(MH_name, MH_upcase);
        name.setTarget(MethodHandles.constant(String.class, "Rocky"));
        String x1 = (String) worker1.invokeExact(); // ClassCastException
        System.out.println(x1);
    }
}

[alexp-sssup]

I can confirm this issue. I've added it to our internal bug tracking system and we'll take a look when we can. Is there any practical use case for this? It seems to be a technical corner case, since it never emerged from any of our customers or internal testing.

[xuwei-k]

I have tried

I have tried run scala lang compiler in web browser. old version work but new version does not work due to MethodHandle, CallSite or something.

https://github.com/xuwei-k/cheerpj-scala/blob/574b8074449df0487a2b50b5750a95f9ff7e1da9/build.sbt#L4-L6

https://xuwei-k.github.io/cheerpj-scala/