Example usage for org.objectweb.asm MethodVisitor visitVarInsn

List of usage examples for org.objectweb.asm MethodVisitor visitVarInsn

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Introduction

In this page you can find the example usage for org.objectweb.asm MethodVisitor visitVarInsn.

Prototype

public void visitVarInsn(final int opcode, final int var)

Source Link

Document

Visits a local variable instruction.

Usage

From source file:com.github.javalbert.bytecode.utils.AsmUtils.java

License:Apache License

public static void visitDefaultConstructor(ClassWriter cw, String classTypeDescriptor) {
    MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
    mv.visitCode();/*from   w ww .j a  v  a 2  s  .c  o  m*/
    Label l0 = new Label();
    mv.visitLabel(l0);
    mv.visitVarInsn(ALOAD, 0);
    mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
    mv.visitInsn(RETURN);
    Label l1 = new Label();
    mv.visitLabel(l1);
    mv.visitLocalVariable("this", classTypeDescriptor, null, l0, l1, 0);
    mv.visitMaxs(1, 1);
    mv.visitEnd();
}

From source file:com.github.rgcjonas.kuemmelgtr.core.Compiler.java

License:Open Source License

public static byte[] compileFunc(TokenSource<RPNToken> source, String variable) throws ParsingError {
    // initialize class
    ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_FRAMES);

    writer.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC, "com/github/rgcjonas/kuemmelgtr/jit/BogusName", null,
            CompiledClassBase.class.getName().replace('.', '/'),
            new String[] { Evaluator.Function.class.getName().replace('.', '/') });

    // create constructor
    MethodVisitor construct = writer.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
    construct.visitCode();/*from w w  w.  j  a v a2s. c o m*/
    construct.visitVarInsn(Opcodes.ALOAD, 0);
    construct.visitMethodInsn(Opcodes.INVOKESPECIAL, CompiledClassBase.class.getName().replace('.', '/'),
            "<init>", "()V");
    construct.visitInsn(Opcodes.RETURN);
    construct.visitMaxs(0, 0);
    construct.visitEnd();

    MethodVisitor method = writer.visitMethod(Opcodes.ACC_PUBLIC, "evaluate", "(D)D", null,
            new String[] { "com/github/rgcjonas/kuemmelgtr/core/RuntimeError" });

    compileCommon(source, method, variable);

    writer.visitEnd();
    return writer.toByteArray();
}

From source file:com.github.rgcjonas.kuemmelgtr.core.Compiler.java

License:Open Source License

public static byte[] compileBasic(TokenSource<RPNToken> source) throws ParsingError {
    // initialize class
    ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_FRAMES);

    writer.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC, "com/github/rgcjonas/kuemmelgtr/jit/BogusName", null,
            CompiledClassBase.class.getName().replace('.', '/'),
            new String[] { Evaluator.Basic.class.getName().replace('.', '/') });

    // create constructor
    MethodVisitor construct = writer.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
    construct.visitCode();//from w  w  w.  jav a  2  s . c om
    construct.visitVarInsn(Opcodes.ALOAD, 0);
    construct.visitMethodInsn(Opcodes.INVOKESPECIAL, CompiledClassBase.class.getName().replace('.', '/'),
            "<init>", "()V");
    construct.visitInsn(Opcodes.RETURN);
    construct.visitMaxs(0, 0);
    construct.visitEnd();

    MethodVisitor method = writer.visitMethod(Opcodes.ACC_PUBLIC, "evaluate", "()D", null,
            new String[] { "com/github/rgcjonas/kuemmelgtr/core/ParsingError",
                    "com/github/rgcjonas/kuemmelgtr/core/RuntimeError" });

    compileCommon(source, method, null);

    writer.visitEnd();
    return writer.toByteArray();
}

From source file:com.github.rgcjonas.kuemmelgtr.core.Compiler.java

License:Open Source License

private static void compileCommon(TokenSource<RPNToken> source, MethodVisitor method, String variable)
        throws ParsingError {
    method.visitCode();//from w ww.ja  va  2 s .  c o m

    // we now can compile our token stream
    int currentStackSize = 0; // we keep track of the current stack size to throw errors if we encounter an invalid instruction
    RPNToken t;
    while ((t = source.nextToken()) != null) {
        if (t instanceof RPNToken.Operand) {
            // we push it onto the stack
            method.visitLdcInsn(((RPNToken.Operand) t).getValue());
            currentStackSize++;
        } else if (t instanceof RPNToken.Operator) {
            RPNToken.Operator op = (RPNToken.Operator) t;

            if (currentStackSize < op.getNumOperands())
                throw new ParsingError(t.getSrcLine(), t.getSrcColumn(), "Missing operand(s)");

            switch (op.getName()) {
            case "_add":
                method.visitInsn(Opcodes.DADD);
                currentStackSize--;
                break;
            case "_mult":
                method.visitInsn(Opcodes.DMUL);
                currentStackSize--;
                break;
            case "_sub":
                method.visitInsn(Opcodes.DSUB);
                currentStackSize--;
                break;
            case "_div":
                method.visitInsn(Opcodes.DDIV);
                currentStackSize--;
                break;
            case "_pow":
                method.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Math", "pow", "(DD)D");
                currentStackSize--;
                break;
            default:
                //HACK: support every function in java/lang/Math. Will be way more performant than any lookup-and-evaluate
                //TODO: implement more functions inline
                if (currentStackSize < 1)
                    throw new ParsingError(t.getSrcLine(), t.getSrcColumn(), "Missing operand");
                try {
                    Method meth = Math.class.getDeclaredMethod(op.getName(), double.class); // just check if it's available and hope it returns a double
                    if (meth.getReturnType() != double.class)
                        throw new NoSuchMethodException(); // we don't want to blow up at runtime, do we?

                    method.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Math", op.getName(), "(D)D");
                } catch (NoSuchMethodException e) {
                    // we do not give up. The method may be available at runtime.
                    method.visitVarInsn(Opcodes.ALOAD, 0);
                    method.visitInsn(Opcodes.DUP_X2); // swap the this pointer and double
                    method.visitInsn(Opcodes.POP);
                    method.visitLdcInsn(op.getName());
                    method.visitLdcInsn((int) op.getSrcLine());
                    method.visitLdcInsn((int) op.getSrcColumn());
                    method.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                            CompiledClassBase.class.getName().replace('.', '/'), "resolveAndEvaluateFunction",
                            "(DLjava/lang/String;II)D");
                }
            }
        } else if (t instanceof RPNToken.VariableRecall) {
            // maybe, maybe the variable is an argument we can load
            if (variable != null && ((RPNToken.VariableRecall) t).getName().equalsIgnoreCase(variable)) {
                method.visitVarInsn(Opcodes.DLOAD, 1);
            } else {
                // we let our parent class do the hard work
                method.visitVarInsn(Opcodes.ALOAD, 0);
                method.visitLdcInsn(((RPNToken.VariableRecall) t).getName());
                method.visitLdcInsn(t.getSrcLine());
                method.visitLdcInsn(t.getSrcColumn());
                method.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                        CompiledClassBase.class.getName().replace('.', '/'), "getVariable",
                        "(Ljava/lang/String;II)D");
            }
            currentStackSize++;
        } else if (t instanceof RPNToken.VariableAssignment) {
            // also defer to our parent class
            // we do not give up. The method may be available at runtime.
            method.visitVarInsn(Opcodes.ALOAD, 0);
            method.visitInsn(Opcodes.DUP_X2); // swap the this pointer and double
            method.visitInsn(Opcodes.POP);
            method.visitLdcInsn(((RPNToken.VariableAssignment) t).getVariableName());
            method.visitLdcInsn(t.getSrcLine());
            method.visitLdcInsn(t.getSrcColumn());
            method.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CompiledClassBase.class.getName().replace('.', '/'),
                    "setVariable", "(DLjava/lang/String;II)D");
        } else {
            throw new ParsingError(t.getSrcLine(), t.getSrcColumn(), "Unknown instruction: " + t);
        }
    }

    if (currentStackSize != 1)
        throw new ParsingError(0, 0, "Expected stack to be one value, found " + currentStackSize);

    method.visitInsn(Opcodes.DRETURN);

    method.visitMaxs(0, 0);
    method.visitEnd();
}

From source file:com.github.stokito.gag.agent.AnswerToLifeGenerator.java

License:Apache License

@Override
public MethodVisitor visitMethod(int access, String name, String desc, String sig, String[] exceptions) {

    MethodVisitor mv = writer().visitMethod(access, name, desc, sig, exceptions);
    mv.visitCode();/*  w ww . j a  v  a 2s.c om*/

    MethodInfo method = classInfo().getMethod(name, desc);
    for (LocalVarInfo param : method.getLocalVars()) {
        AnnoInfo anno = param.getAnnoFor(ANSWER_TYPE);
        if (anno == null) {
            continue;
        }

        Type paramType = param.getType();
        switch (paramType.getSort()) {
        case Type.INT:
        case Type.BYTE:
        case Type.CHAR:
        case Type.SHORT:
            mv.visitLdcInsn(FORTY_TWO);
            mv.visitVarInsn(ISTORE, param.getIndex());
            break;
        case Type.LONG:
            mv.visitLdcInsn((long) FORTY_TWO);
            mv.visitVarInsn(LSTORE, param.getIndex());
            break;
        case Type.DOUBLE:
            mv.visitLdcInsn((double) FORTY_TWO);
            mv.visitVarInsn(DSTORE, param.getIndex());
            break;
        case Type.FLOAT:
            mv.visitLdcInsn((float) FORTY_TWO);
            mv.visitVarInsn(FSTORE, param.getIndex());
            break;
        case Type.OBJECT:
            visitObject(mv, param);
            break;
        default:
            throwUnsupportedException(param);
        }

        setInstrumented(true);
    }

    mv.visitEnd();
    return mv;
}

From source file:com.github.stokito.gag.agent.AnswerToLifeGenerator.java

License:Apache License

/** TODO: Support BigDecimal and BigInteger. */
private void visitObject(MethodVisitor mv, LocalVarInfo param) {
    Type paramType = param.getType();
    if (Type.getType(Character.class).equals(paramType)) {
        mv.visitLdcInsn((char) FORTY_TWO);
        mv.visitMethodInsn(INVOKESTATIC, paramType.getInternalName(), "valueOf",
                "(C)L" + paramType.getInternalName() + ";");
        mv.visitVarInsn(ASTORE, param.getIndex());
    } else if (supportedValueOfTypes.contains(paramType)) {
        mv.visitLdcInsn(String.valueOf(FORTY_TWO));
        mv.visitMethodInsn(INVOKESTATIC, paramType.getInternalName(), "valueOf",
                "(Ljava/lang/String;)L" + paramType.getInternalName() + ";");
        mv.visitVarInsn(ASTORE, param.getIndex());
    } else {/* w ww  .  ja v a2  s  .c o m*/
        throwUnsupportedException(param);
    }
}

From source file:com.github.stokito.gag.agent.ThisHadBetterGenerator.java

License:Apache License

private static void visitComparable(MethodVisitor mv, boolean be, Property property, LocalVarInfo param,
        Label okay) {//w ww  .j  a va2 s .  com

    Type type = param.getType();
    int index = param.getIndex();

    switch (type.getSort()) {
    case Type.INT:
    case Type.SHORT:
        mv.visitVarInsn(ILOAD, index);
        break;
    case Type.LONG:
        mv.visitVarInsn(LLOAD, index);
        mv.visitInsn(LCONST_0);
        mv.visitInsn(LCMP);
        break;
    case Type.DOUBLE:
        mv.visitVarInsn(DLOAD, index);
        mv.visitInsn(DCONST_0);
        mv.visitInsn(DCMPG);
        break;
    case Type.FLOAT:
        mv.visitVarInsn(FLOAD, index);
        mv.visitInsn(FCONST_0);
        mv.visitInsn(FCMPG);
        break;
    case Type.OBJECT:
        if (type.equals(Type.getType(Integer.class))) {
            mv.visitVarInsn(ALOAD, index);
            mv.visitMethodInsn(INVOKEVIRTUAL, Type.getType(Integer.class).getInternalName(), "intValue", "()I");
        } else if (type.equals(Type.getType(Short.class))) {
            mv.visitVarInsn(ALOAD, index);
            mv.visitMethodInsn(INVOKEVIRTUAL, Type.getType(Short.class).getInternalName(), "intValue", "()I");
        } else if (type.equals(Type.getType(Long.class))) {
            mv.visitVarInsn(ALOAD, index);
            mv.visitMethodInsn(INVOKEVIRTUAL, Type.getType(Long.class).getInternalName(), "longValue", "()J");
            mv.visitInsn(LCONST_0);
            mv.visitInsn(LCMP);
        } else if (type.equals(Type.getType(Double.class))) {
            mv.visitVarInsn(ALOAD, index);
            mv.visitMethodInsn(INVOKEVIRTUAL, Type.getType(Double.class).getInternalName(), "doubleValue",
                    "()D");
            mv.visitInsn(DCONST_0);
            mv.visitInsn(DCMPG);
        } else if (type.equals(Type.getType(Float.class))) {
            mv.visitVarInsn(ALOAD, index);
            mv.visitMethodInsn(INVOKEVIRTUAL, Type.getType(Float.class).getInternalName(), "floatValue", "()F");
            mv.visitInsn(FCONST_0);
            mv.visitInsn(FCMPG);
        } else {
            throw new AnnotationStateError("Unsupported type: " + type);
        }
        break;
    default:
        throw new AnnotationStateError("Unsupported type: " + type);
    }

    switch (property) {
    case NEGATIVE:
        mv.visitJumpInsn(be ? IFLT : IFGE, okay);
        break;
    case POSITIVE:
        mv.visitJumpInsn(be ? IFGT : IFLE, okay);
        break;
    case ZERO:
        mv.visitJumpInsn(be ? IFEQ : IFNE, okay);
        break;
    }
}

From source file:com.github.stokito.gag.agent.ThisHadBetterGenerator.java

License:Apache License

private static void visitNullCheck(MethodVisitor mv, boolean be, LocalVarInfo param, Label okay) {
    switch (param.getType().getSort()) {
    case Type.ARRAY:
    case Type.OBJECT:
        mv.visitVarInsn(ALOAD, param.getIndex());
        break;//from w  w  w  .j  av a2 s.c  o m
    default:
        throw new AnnotationStateError("Unsupported type: " + param.getType());
    }

    mv.visitJumpInsn(be ? IFNULL : IFNONNULL, okay);
}

From source file:com.github.stokito.gag.agent.ThisHadBetterGenerator.java

License:Apache License

/**
 * The given Property needs to be either {@link Property#THE_BLUE_PILL} or
 * {@link Property#THE_RED_PILL}.//from  w ww  . j a va  2 s.c om
 */
private static void visitPill(MethodVisitor mv, boolean be, Property property, LocalVarInfo param, Label okay) {

    if (param.getType().getSort() != Type.OBJECT) {
        throw new AnnotationStateError("Unsupported type: " + param.getType());
    }

    // TODO: Also handle if parameter is null.

    Label notOkay = new Label();

    // See if the param type matches a Pill type
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitMethodInsn(INVOKEVIRTUAL, param.getType().getInternalName(), "getClass", "()Ljava/lang/Class;");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Class", "getName", "()Ljava/lang/String;");
    mv.visitLdcInsn("Pill|ThePill|.*[\\.$]Pill|.*[\\.$]ThePill");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "matches", "(Ljava/lang/String;)Z");

    if (be) {
        // If the param type does not match a Pill type, that's not okay, go to exception.
        mv.visitJumpInsn(FALSE, notOkay);
    } else {
        // If the param type does not match a Pill type, then that's okay, skip exception.
        mv.visitJumpInsn(FALSE, okay);
    }

    // At this point, the param type matches a Pill type.
    // So check if the param type is an enum type.
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitTypeInsn(INSTANCEOF, "java/lang/Enum");

    if (be) {
        // If the param type is not an enum, that's not okay, go to exception.
        mv.visitJumpInsn(FALSE, notOkay);
    } else {
        // If the param type is not an enum, that's okay, skip exception.
        mv.visitJumpInsn(FALSE, okay);
    }

    // Check that the Pill type has the property specified in the annotation.
    // First try to match on "BLUE" (or "RED").
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitTypeInsn(CHECKCAST, "java/lang/Enum");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Enum", "name", "()Ljava/lang/String;");
    mv.visitLdcInsn(property == THE_BLUE_PILL ? "BLUE" : "RED");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "equals", "(Ljava/lang/Object;)Z");
    mv.visitJumpInsn(TRUE, be ? okay : notOkay);

    // Then try to see if the value ends with "BLUE_PILL" (or "RED_PILL").
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitTypeInsn(CHECKCAST, "java/lang/Enum");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Enum", "name", "()Ljava/lang/String;");
    mv.visitLdcInsn(property == THE_BLUE_PILL ? "BLUE_PILL" : "RED_PILL");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "endsWith", "(Ljava/lang/String;)Z");
    mv.visitJumpInsn(be ? TRUE : FALSE, okay);

    mv.visitLabel(notOkay);
}

From source file:com.github.stokito.gag.agent.ThisHadBetterGenerator.java

License:Apache License

private static void visitDeathStarPlans(MethodVisitor mv, boolean be, LocalVarInfo param, Label okay) {

    if (param.getType().getSort() != Type.OBJECT) {
        throw new AnnotationStateError("Unsupported type: " + param.getType());
    }/*from   w  ww  .ja  v  a 2  s  . co  m*/

    Label notOkay = new Label();

    // See if the param type matches a DeathStarPlans type
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitMethodInsn(INVOKEVIRTUAL, param.getType().getInternalName(), "getClass", "()Ljava/lang/Class;");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Class", "getName", "()Ljava/lang/String;");
    mv.visitLdcInsn("DeathStarPlans|TheDeathStarPlans|.*[\\.$]DeathStarPlans|.*[\\.$]TheDeathStarPlans");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "matches", "(Ljava/lang/String;)Z");

    if (be) {
        // If the param type does not match a DeathStarPlans type, that's not okay, go to exception.
        mv.visitJumpInsn(FALSE, notOkay);
    } else {
        // If the param type does not match a DeathStarPlans type, then that's okay, skip exception.
        mv.visitJumpInsn(FALSE, okay);
    }

    // At this point, the param type matches a DeathStarPlans type.
    // So check if the param has an isStolen method.
    Label start = new Label();
    Label end = new Label();
    Label handler = new Label();
    mv.visitTryCatchBlock(start, end, handler, null);

    mv.visitLabel(start);
    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitMethodInsn(INVOKEVIRTUAL, param.getType().getInternalName(), "getClass", "()Ljava/lang/Class;");
    mv.visitLdcInsn("isStolen");
    mv.visitInsn(ACONST_NULL);
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Class", "getMethod",
            "(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;");

    mv.visitVarInsn(ALOAD, param.getIndex());
    mv.visitInsn(ACONST_NULL);
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/reflect/Method", "invoke",
            "(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;");
    mv.visitTypeInsn(CHECKCAST, "java/lang/Boolean");
    mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z");

    mv.visitJumpInsn(be ? TRUE : FALSE, okay);

    mv.visitLabel(end);
    mv.visitJumpInsn(GOTO, notOkay);
    mv.visitLabel(handler);
    mv.visitInsn(POP);

    mv.visitLabel(notOkay);
}