Obzcure Virtual Machine

Java virtual machine made in Java

THIS IS NOT PRODUCTION SAFE - WORK IN PROGRESS!

Use at your own risk.
Requires Java 17 (with preview features)

java --enable-preview -jar ObzcureVM.jar
"path/to/java17" --enable-preview -jar ObzcureVM.jar -i in.jar -o out.jar -fp -rf -rm -sd
"C:\Program Files\Java\graalvm-ce-java17-21.3.0\bin\java.exe" --enable-preview -jar ObzcureVM.jar -i in.jar -o out.jar -fp -rf -rm -sd

The virtualized output jar also now requires Java 17 (with preview features)

Usage:
 -fp,--forcePublic      Make every field and method public (accessible
                        from everywhere)
 -i,--input <input>     Input jar file
 -o,--output <output>   Output jar file
 -rf,--removeFinal      Force virtualization of final fields (removes
                        final access)
 -rm,--rndMeow          Random cats.meow filename
 -sd,--skipDebug        Remove debugging information from all classes

Before

After

Example timings:

Virtualized output file:

5458 ms
5011 ms
4947 ms
4873 ms
4937 ms

Original input file:

53 ms
18 ms
21 ms
12 ms
9 ms

As you can see from these 5 test runs, the virtualized version of a jar is up to 606 times slower than the original jar.
This is a worst case scenario, where a huge jar was fully virtualized including lots of nested loops.
If you only virtualize a few specific methods, it shouldn't be much slower than the original.

Releases(Alpha)

Alpha(Feb 7, 2022)

Don't want to compile? Download this and run with Java 17 (using the preview feature flag --enable-preview)
Source code(tar.gz)
Source code(zip)
ObzcureVM-1.0.0.jar(685.35 KB)