Mute warnings for using deprecated and unsafe methods

[wfouche]

Fixes #21 when using Java 24 or Java 25

[wfouche]

@jeff5 , this is the next PR to prioritize.

The fix supresses these two warning messages when Java 24 or Java 25 is detected:

$ jbang run jython-cli@jython
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.kenai.jffi.internal.StubLoader in an unnamed module (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::putLong has been called by com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64 (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Please consider reporting this to the maintainers of class com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64
WARNING: sun.misc.Unsafe::putLong will be removed in a future release
Jython 2.7.4 (tags/v2.7.4:3f256f4a7, Aug 18 2024, 16:49:39)
[OpenJDK 64-Bit Server VM (Eclipse Adoptium)] on java25
Type "help", "copyright", "credits" or "license" for more information.

Also see https://openjdk.org/jeps/498

[wfouche]

Console output when using Java 23

$ jbang run jython-cli@jython
Jython 2.7.4 (tags/v2.7.4:3f256f4a7, Aug 18 2024, 16:49:39)
[OpenJDK 64-Bit Server VM (Eclipse Adoptium)] on java23.0.2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Console output when using Java 24

$ jbang run jython-cli@jython
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.kenai.jffi.internal.StubLoader in an unnamed module (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::putLong has been called by com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64 (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Please consider reporting this to the maintainers of class com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64
WARNING: sun.misc.Unsafe::putLong will be removed in a future release
Jython 2.7.4 (tags/v2.7.4:3f256f4a7, Aug 18 2024, 16:49:39)
[OpenJDK 64-Bit Server VM (Eclipse Adoptium)] on java24.0.2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Console output when using Java 25

$ jbang run jython-cli@jython
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.kenai.jffi.internal.StubLoader in an unnamed module (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::putLong has been called by com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64 (file:/home/wfouche/.m2/repository/com/github/jnr/jffi/1.3.13/jffi-1.3.13.jar)
WARNING: Please consider reporting this to the maintainers of class com.kenai.jffi.UnsafeMemoryIO$UnsafeMemoryIO64
WARNING: sun.misc.Unsafe::putLong will be removed in a future release
Jython 2.7.4 (tags/v2.7.4:3f256f4a7, Aug 18 2024, 16:49:39)
[OpenJDK 64-Bit Server VM (Eclipse Adoptium)] on java24.0.2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

[jeff5]

I'm broadly against suppressing warnings. This code will break in a later version of Java: best not pretend otherwise. Thanks however for testing.

If you have a way of avoiding the problem they warn us of, that's a different matter.

[wfouche]

This is a warning message for the developers of Jython, and not the users of Jython. It says that an updated version of jffi is needed and this seems to be work in progress: jnr/jffi#165

Why bother the Jython user with warnings, if they can do nothing about it and it also do not affect them at the moment?

It makes for a cleaner user experience, so that is why I am in favour of suppressing these two warning (for now).

[jeff5]

Why bother the Jython user with warnings, if they can do nothing about it and it also do not affect them at the moment?

It's so they know it will break if they move up to Java 26, and they can press JNR/JFFI. I'm pretty sure this is what's in the mind of the JDK developers.