beejava

compiles java 'opcode' to bytecode.

What is 'opcode'?

The goal of the project is to let developers use a simplified version of standard java opcodes. For instance: instead of having to choose between:

INVOKE_SPECIAL
INVOKE_VIRTUAL
INVOKE_DYNAMIC
INVOKE_INTERFACE

developers can just write INVOKE and the compiler will figure out the correct instruction to put in the class file.

project status:

early stage

At this moment a complete compile cycle is guaranteed (unittested) for a really simple class.

Code example below, but the API will undoubtedly change.

BeeSource createEmptyClass() {
    return BeeSource.builder()
           .withClassFileVersion(Version.V14)
           .withPackage("nl.sander.beejava.test")
           .withAccessFlags(PUBLIC, SUPER)
           .withSimpleName("EmptyBean")
           .withSuperClass(Object.class) // Not mandatory, like in java sourcecode
           .withConstructors(createDefaultConstructor()) // There's no default constructor in beejava. The user must always add them
           .build();
}

BeeConstructor createDefaultConstructor() {
    return BeeConstructor.builder()
            .withAccessFlags(MethodAccessFlags.PUBLIC)
            .withCode(
                    line(0, LD_VAR, Ref.THIS),
                    line(1, INVOKE, Ref.SUPER, "<init>", "()"),
                    line(5, RETURN))
            .build();
 }

Ideas about what's next

MORE opcodes
invoke dynamic support (also in constant pool)
support for exceptions, class attributes
figure out a nicer, better api, drop the line numbers
or instead drop this idea and let the developer write the raw bytecode. The constant pool would then be the only thing Beejava adds.
create a readable file format for opcode files

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beejava

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Raw Blame History