Examples with ClassReader jdk.internal.org.objectweb.asm.ClassReader used on opensource projects

Example 6 with ClassReader

use of jdk.internal.org.objectweb.asm.ClassReader in project openj9 by eclipse.

the class Transformer method transform.

public byte[] transform(ClassLoader loader, String className, Class<?> classToTransform, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
    try {
        if (flag == MODIFY_EXISTING_METHOD) {
            // for fast HCR
            AgentMain.logger.debug("Instrumenting " + className + " by modifying existing method.");
            ClassReader reader = new ClassReader(classToTransform.getCanonicalName());
            ClassWriter cw = new ClassWriter(reader, ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
            ClassVisitor visitor = new CustomClassVisitor(cw, classToTransform.getCanonicalName());
            reader.accept(visitor, ClassReader.EXPAND_FRAMES);
            return cw.toByteArray();
        } else if (flag == ADD_NEW_METHOD) {
            // for extended HCR
            AgentMain.logger.debug("Instrumenting " + className + " by adding a new method.");
            ClassReader reader = new ClassReader(classToTransform.getCanonicalName());
            ClassWriter cw = new ClassWriter(reader, ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
            ClassVisitor cv = new MethodAddAdapter(new CheckClassAdapter(cw));
            reader.accept(cv, ClassReader.SKIP_FRAMES);
            return cw.toByteArray();
        } else if (flag == ADD_NEW_FIELD) {
            // for GCRetransform test
            AgentMain.logger.debug("Instrumenting " + className + " by adding a new field.");
            ClassReader reader = new ClassReader(classToTransform.getCanonicalName());
            ClassWriter cw = new ClassWriter(reader, ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
            FieldNode newField = new FieldNode(Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, "new_static_int_array", "[I", null, null);
            ClassVisitor cv = new FieldAdder(new CheckClassAdapter(cw), newField, className, _methodName);
            reader.accept(cv, ClassReader.SKIP_FRAMES);
            return cw.toByteArray();
        }
        return null;
    } catch (IOException e) {
        return null;
    }
}

Example 7 with ClassReader

use of jdk.internal.org.objectweb.asm.ClassReader in project Bytecoder by mirkosertic.

the class ASMifier method main.

/**
 * Prints the ASM source code to generate the given class to the standard
 * output.
 * <p>
 * Usage: ASMifier [-debug] &lt;binary class name or class file name&gt;
 *
 * @param args
 *            the command line arguments.
 *
 * @throws Exception
 *             if the class cannot be found, or if an IO exception occurs.
 */
public static void main(final String[] args) throws Exception {
    int i = 0;
    int flags = ClassReader.SKIP_DEBUG;
    boolean ok = true;
    if (args.length < 1 || args.length > 2) {
        ok = false;
    }
    if (ok && "-debug".equals(args[0])) {
        i = 1;
        flags = 0;
        if (args.length != 2) {
            ok = false;
        }
    }
    if (!ok) {
        System.err.println("Prints the ASM code to generate the given class.");
        System.err.println("Usage: ASMifier [-debug] " + "<fully qualified class name or class file name>");
        return;
    }
    ClassReader cr;
    if (args[i].endsWith(".class") || args[i].indexOf('\\') > -1 || args[i].indexOf('/') > -1) {
        cr = new ClassReader(new FileInputStream(args[i]));
    } else {
        cr = new ClassReader(args[i]);
    }
    cr.accept(new TraceClassVisitor(null, new ASMifier(), new PrintWriter(System.out)), flags);
}

Example 8 with ClassReader

use of jdk.internal.org.objectweb.asm.ClassReader in project Bytecoder by mirkosertic.

the class CheckClassAdapter method main.

/**
 * Checks a given class.
 * <p>
 * Usage: CheckClassAdapter &lt;binary class name or class file name&gt;
 *
 * @param args
 *            the command line arguments.
 *
 * @throws Exception
 *             if the class cannot be found, or if an IO exception occurs.
 */
public static void main(final String[] args) throws Exception {
    if (args.length != 1) {
        System.err.println("Verifies the given class.");
        System.err.println("Usage: CheckClassAdapter " + "<fully qualified class name or class file name>");
        return;
    }
    ClassReader cr;
    if (args[0].endsWith(".class")) {
        cr = new ClassReader(new FileInputStream(args[0]));
    } else {
        cr = new ClassReader(args[0]);
    }
    verify(cr, false, new PrintWriter(System.err));
}

Example 9 with ClassReader

use of jdk.internal.org.objectweb.asm.ClassReader in project Bytecoder by mirkosertic.

the class ModuleInfoExtender method toByteArray.

/**
 * Returns the bytes of the modified module-info.class.
 * Once this method has been called then the Extender object should
 * be discarded.
 */
public byte[] toByteArray() throws IOException {
    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
    AttributeAddingClassVisitor cv = new AttributeAddingClassVisitor(Opcodes.ASM5, cw);
    ClassReader cr = new ClassReader(in);
    if (packages != null)
        cv.addAttribute(new ModulePackagesAttribute(packages));
    if (mainClass != null)
        cv.addAttribute(new ModuleMainClassAttribute(mainClass));
    if (targetPlatform != null)
        cv.addAttribute(new ModuleTargetAttribute(targetPlatform));
    if (hashes != null)
        cv.addAttribute(new ModuleHashesAttribute(hashes));
    if (moduleResolution != null)
        cv.addAttribute(new ModuleResolutionAttribute(moduleResolution.value()));
    List<Attribute> attrs = new ArrayList<>();
    // prototypes of attributes that should be parsed
    attrs.add(new ModuleAttribute(version));
    attrs.add(new ModulePackagesAttribute());
    attrs.add(new ModuleMainClassAttribute());
    attrs.add(new ModuleTargetAttribute());
    attrs.add(new ModuleHashesAttribute());
    cr.accept(cv, attrs.toArray(new Attribute[0]), 0);
    // add any attributes that didn't replace previous attributes
    cv.finish();
    return cw.toByteArray();
}

Example 10 with ClassReader

use of jdk.internal.org.objectweb.asm.ClassReader in project CorfuDB by CorfuDB.

the class Utils method printByteCode.

public static String printByteCode(byte[] bytes) {
    ClassReader cr = new ClassReader(bytes);
    ClassNode cn = new ClassNode();
    cr.accept(cn, 0);
    final List<MethodNode> methods = cn.methods;
    StringBuilder sb = new StringBuilder();
    for (MethodNode m : methods) {
        InsnList inList = m.instructions;
        sb.append(m.name);
        for (int i = 0; i < inList.size(); i++) {
            sb.append(insnToString(inList.get(i)));
        }
    }
    return sb.toString();
}