test.GenSourceDebugExtension.java Source code

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Here is the source code for test.GenSourceDebugExtension.java

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// Copyright 2015 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package test;

import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.jar.JarOutputStream;
import java.util.zip.ZipEntry;

public class GenSourceDebugExtension {
    public static void main(String[] args) throws IOException {
        try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(args[0]))) {
            jos.putNextEntry(new ZipEntry("sourcedebugextension/Test.class"));
            jos.write(dump());
        }
    }

    public static byte[] dump() {
        ClassWriter cw = new ClassWriter(0);
        MethodVisitor mv;

        cw.visit(52, Opcodes.ACC_PUBLIC + Opcodes.ACC_SUPER, "sourcedebugextension/Test", null, "java/lang/Object",
                null);

        // This is the important part for the test - it's an example SourceDebugExtension found
        // in Clojure.
        cw.visitSource("dispatch.clj",
                "SMAP\ndispatch.java\nClojure\n*S Clojure\n*F\n+ 1 dispatch.clj\nclojure/pprint/dispatch.clj\n*L\n144#1,8:144\n*E");

        {
            mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
            mv.visitCode();
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
            mv.visitInsn(Opcodes.RETURN);
            mv.visitMaxs(1, 1);
            mv.visitEnd();
        }
        {
            mv = cw.visitMethod(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, "main", "([Ljava/lang/String;)V", null,
                    null);
            mv.visitCode();
            mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "err", "Ljava/io/PrintStream;");
            mv.visitLdcInsn("Hello");
            mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V",
                    false);
            mv.visitInsn(Opcodes.RETURN);
            mv.visitMaxs(2, 1);
            mv.visitEnd();
        }
        cw.visitEnd();

        return cw.toByteArray();
    }
}