add detection for IBM Semeru Java runtime and fix x86 detection on 64 bit Windows

[Fourmisain]

IBM Semeru uses OpenJ9, which is known to be quite memory efficient, making it potentially interesting for large modpacks.

The detection code is a straight forward copy of the Eclipse Adoptium detection, substituting
Eclipse Adoptium -> Semeru, ADOPTIUM -> SEMERU, hotspot -> openj9

Tested working with 8.0.402.0 x64 JDK and 17.0.10.0 x64 JRE. (I assume x86 should just work.)

P.S.
MSYS2's build instructions are missing qt6-networkauth:p in the pacboy step if someone reading wants to fix it.

[Trial97]

Is this only for windows?

[Fourmisain]

Is this only for windows?

Yes. I have no idea how/if detection on Linux is done.

I also just tested x86 and it looks like all the detection code is sort of broken for it.
If you install a 32 bit Java on a 64 bit OS, it generally installs into WOW6432Node, which this code does not test for at all (I thought the KEY_WOW64_32KEY would magically do that).

For comparison, registry paths for x86 and x64 on 64 bit Windows are

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Eclipse Adoptium\JRE\17.0.11.9\hotspot\MSI
HKEY_LOCAL_MACHINE\SOFTWARE\Eclipse Adoptium\JDK\17.0.11.9\hotspot\MSI

I guess it's not a huge deal since you generally won't use 32 bit Java on a 64 bit machine since the only advantage is lower memory consumption, but it's also limited to 4GB, so it's pretty much pointless.

[Ryex]

Hey, just looked into things

looks like on macos ibm semeru would be installed to
/Library/Java/JavaVirtualMachines/ibm-semeru-open-<version>.<jdk|jre>/
with the official installer and similar with homebrew.
/Library/Java/JavaVirtualMachines/ is already checked so no change is needed there.

with linux the official RPM uses

    Certified edition: /opt/ibm
    Open edition: /usr/lib/jvm/

other distros are likely going to use similar
/usr/lib/jvm/ is already checked so only /opt/ibm would need to be added

[Fourmisain]

I just looked into the x86 thing a bit.
I think the code is trying to do the right thing, passing in the KEY_WOW64_32KEY flag into RegOpenKeyExW, which presumably would check the "32 bit registry", which lies inside Wow6432Node... so I'm not sure why it doesn't seem to work.

The docs for RegOpenKeyExW don't help, they don't list any of the used flags...?

Gonna check it out tomorrow, the Linux/macOS detection as well if I can find the code - though I won't be able to test it.

[Fourmisain]

Oh wait, maybe that's the issue?

PrismLauncher/launcher/java/JavaUtils.cpp

Line 210 in 08918be

if (RegOpenKeyExW(HKEY_LOCAL_MACHINE, newKeyName.toStdWString().c_str(), 0, KEY_READ | KEY_WOW64_64KEY, &newKey) ==

It's always using KEY_WOW64_64KEY here.

Anyway. Tomorrow.

[Fourmisain]

I had to quickly test it. It was indeed that.

[Fourmisain]

looks like on macos ibm semeru would be installed to
/Library/Java/JavaVirtualMachines/ibm-semeru-open-.<jdk|jre>/
with the official installer and similar with homebrew.
/Library/Java/JavaVirtualMachines/ is already checked so no change is needed there.

Just read the code as well, I agree that it should already work.

with linux the official RPM uses

Certified edition: /opt/ibm
Open edition: /usr/lib/jvm/

other distros are likely going to use similar
/usr/lib/jvm/ is already checked so only /opt/ibm would need to be added

Added /opt/ibm.

That should be it. Thanks for the help!

[Trial97]

One more thing you need to do is to format your code(to please the pre-commit check).
Here are the changes that you need to make: https://github.com/PrismLauncher/PrismLauncher/pull/2428/checks?check_run_id=25216938174
If the changes are not obvious you can just run clang-format -i launcher/java/JavaUtils.cpp and it should format it.

[Fourmisain]

clang-format -i launcher/java/JavaUtils.cpp didn't quite work, it put
"LD_LIBRARY_PATH",
"LD_PRELOAD"
and
"QT_PLUGIN_PATH",
"QT_FONTPATH"
in a single line, which the pre-commit check didn't like.

Force-pushed the correct formatting.

[github-actions]

Successfully created backport PR for release-8.x:

• [Backport release-8.x] add detection for IBM Semeru Java runtime and fix x86 detection on 64 bit Windows #2483