public Assembler defaultValue(String desc) {
int typeCode = desc.charAt(0);
switch (typeCode) {
case '[':
case 'L':
mv.visitInsn(ACONST_NULL);
break;
case 'Z':
case 'C':
case 'B':
case 'S':
case 'I':
mv.visitInsn(ICONST_0);
break;
case 'J':
mv.visitInsn(LCONST_0);
break;
case 'F':
mv.visitInsn(FCONST_0);
break;
case 'D':
mv.visitInsn(DCONST_0);
break;
}
return this;
}
// print the object on the top of the stack
public Assembler printObject() {
mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
mv.visitInsn(SWAP);
mv.visitMethodInsn(
INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/Object;)V", false);
return this;
}
public Assembler sub(Type t) {
int opcode = -1;
switch (t.getSort()) {
case Type.SHORT:
case Type.BYTE:
case Type.INT:
{
opcode = ISUB;
break;
}
case Type.LONG:
{
opcode = LSUB;
break;
}
case Type.FLOAT:
{
opcode = FSUB;
break;
}
case Type.DOUBLE:
{
opcode = DSUB;
break;
}
}
if (opcode != -1) {
mv.visitInsn(opcode);
}
return this;
}
public Assembler dupReturnValue(int returnOpcode) {
switch (returnOpcode) {
case IRETURN:
case FRETURN:
case ARETURN:
mv.visitInsn(DUP);
break;
case LRETURN:
case DRETURN:
mv.visitInsn(DUP2);
break;
case RETURN:
break;
default:
throw new IllegalArgumentException("not return");
}
return this;
}
/** Generate class bytes for java.lang.Runnable implementation and return the same. */
public byte[] generate(Method method, String className) {
int modifiers = method.getModifiers();
// make sure that the method is public static
// and accepts no arguments
if (!Modifier.isStatic(modifiers)
|| !Modifier.isPublic(modifiers)
|| method.getParameterTypes().length != 0) {
throw new IllegalArgumentException();
}
Class clazz = method.getDeclaringClass();
modifiers = clazz.getModifiers();
// make sure that the class is public as well
if (!Modifier.isPublic(modifiers)) {
throw new IllegalArgumentException();
}
ClassWriter cw = InstrumentUtils.newClassWriter();
cw.visit(
V1_1, ACC_PUBLIC, className, null, "java/lang/Object", new String[] {"java/lang/Runnable"});
// creates a MethodWriter for the (implicit) constructor
MethodVisitor mw = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
// pushes the 'this' variable
mw.visitVarInsn(ALOAD, 0);
// invokes the super class constructor
mw.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
mw.visitInsn(RETURN);
mw.visitMaxs(1, 1);
mw.visitEnd();
// creates a MethodWriter for the 'main' method
mw = cw.visitMethod(ACC_PUBLIC, "run", "()V", null, null);
// invokes the given method
mw.visitMethodInsn(
INVOKESTATIC,
Type.getInternalName(method.getDeclaringClass()),
method.getName(),
Type.getMethodDescriptor(method));
mw.visitInsn(RETURN);
mw.visitMaxs(1, 1);
mw.visitEnd();
return cw.toByteArray();
}
public Assembler push(int value) {
if (value >= -1 && value <= 5) {
mv.visitInsn(ICONST_0 + value);
} else if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE) {
mv.visitIntInsn(BIPUSH, value);
} else if (value >= Short.MIN_VALUE && value <= Short.MAX_VALUE) {
mv.visitIntInsn(SIPUSH, value);
} else {
mv.visitLdcInsn(value);
}
return this;
}
public Assembler dupValue(String desc) {
int typeCode = desc.charAt(0);
switch (typeCode) {
case '[':
case 'L':
case 'Z':
case 'C':
case 'B':
case 'S':
case 'I':
mv.visitInsn(DUP);
break;
case 'J':
case 'D':
mv.visitInsn(DUP2);
break;
default:
throw new RuntimeException("invalid signature");
}
return this;
}
public Assembler ldc(Object o) {
if (o instanceof Integer) {
int i = (int) o;
if (i >= -1 && i <= 5) {
int opcode = -1;
switch (i) {
case 0:
{
opcode = ICONST_0;
break;
}
case 1:
{
opcode = ICONST_1;
break;
}
case 2:
{
opcode = ICONST_2;
break;
}
case 3:
{
opcode = ICONST_3;
break;
}
case 4:
{
opcode = ICONST_4;
break;
}
case 5:
{
opcode = ICONST_5;
break;
}
case -1:
{
opcode = ICONST_M1;
break;
}
}
mv.visitInsn(opcode);
return this;
}
}
if (o instanceof Long) {
long l = (long) o;
if (l >= 0 && l <= 1) {
int opcode = -1;
switch ((int) l) {
case 0:
{
opcode = LCONST_0;
break;
}
case 1:
{
opcode = LCONST_1;
break;
}
}
mv.visitInsn(opcode);
return this;
}
}
mv.visitLdcInsn(o);
return this;
}
public Assembler arrayStore(Type type) {
mv.visitInsn(type.getOpcode(IASTORE));
return this;
}
public Assembler arrayLoad(Type type) {
mv.visitInsn(type.getOpcode(IALOAD));
return this;
}
public Assembler swap() {
mv.visitInsn(SWAP);
return this;
}
public Assembler dup2() {
mv.visitInsn(DUP2);
return this;
}
public Assembler pop() {
mv.visitInsn(POP);
return this;
}
public Assembler loadNull() {
mv.visitInsn(ACONST_NULL);
return this;
}