Static rule creates broken parser

[akirschbaum]

A rule that is declared "static" causes a "java.lang.VerifyError" during parser generation. Instead Grappa should either support this or else should generate a proper error message.

$ gradle
:compileJava
Download http://repo1.maven.org/maven2/com/github/fge/grappa/2.0.0/grappa-2.0.0.jar
:processResources UP-TO-DATE
:classes
:run
Exception in thread "main" java.lang.VerifyError: Bad local variable type
Exception Details:
  Location:
    app/Main$Parser$$grappa.rule()Lcom/github/fge/grappa/rules/Rule; @0: aload_0
  Reason:
    Type top (current frame, locals[0]) is not assignable to reference type
  Current Frame:
    bci: @0
    flags: { }
    locals: { }
    stack: { }
  Bytecode:
    0x0000000: 2ab4 01a1 59c6 0004 b057 bb00 3059 b700
    0x0000010: 3459 2a5f b501 a12a b701 a359 c600 0b13
    0x0000020: 01a4 b900 4702 005a c000 49b6 004d 592a
    0x0000030: 5fb5 01a1 b0
  Stackmap Table:
    same_locals_1_stack_item_frame(@9,Object[#67])
    full_frame(@39,{},{Object[#48],Object[#67]})

        at java.lang.Class.getDeclaredConstructors0(Native Method)
        at java.lang.Class.privateGetDeclaredConstructors(Class.java:2663)
        at java.lang.Class.getConstructors(Class.java:1643)
        at com.github.fge.grappa.Grappa.findConstructor(Grappa.java:111)
        at com.github.fge.grappa.Grappa.createParser(Grappa.java:67)
        at app.Main.main(Main.java:12)
:run FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':run'.
> Process 'command '/usr/local/java/64/jdk1.8.0_31/bin/java'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 7.967 secs
$ cat build.gradle
defaultTasks 'run'

apply plugin: 'application'
apply plugin: 'java'

sourceCompatibility = 1.8
mainClassName = 'app.Main'

dependencies {
    compile 'com.github.fge:grappa:2.0.0'
}

repositories {
    mavenCentral()
}
$ cat src/main/java/app/Main.java
package app;

import com.github.fge.grappa.Grappa;
import com.github.fge.grappa.buffers.CharSequenceInputBuffer;
import com.github.fge.grappa.parsers.BaseParser;
import com.github.fge.grappa.rules.Rule;
import com.github.fge.grappa.run.ListeningParseRunner;

public class Main {

    public static void main(final String[] args) {
        new ListeningParseRunner<>(Grappa.createParser(Parser.class).rule()).run(new CharSequenceInputBuffer("a"));
    }

    public static class Parser extends BaseParser<Object> {

        public static Rule rule() {
            return ANY;
        }

    }

}

[fge]

Uuh... OK, fair point.

This is the first usage ever I have seen of static rules to be honest :)