serp.bytecode.ConstantInstruction Maven / Gradle / Ivy
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package serp.bytecode;
import java.io.*;
import serp.bytecode.lowlevel.*;
import serp.bytecode.visitor.*;
import serp.util.*;
/**
* An instruction that that loads a constant onto the stack.
* The opcode represented by this instruction may change depending on the
* type and value of the constant set. For example, if the constant value
* is initially set to 5, the opcode will be iconst5; if later
* incremented to 6, the opcode will be changed to bipush(6).
*
* @author Abe White
*/
public class ConstantInstruction extends TypedInstruction {
private int _arg = -1;
ConstantInstruction(Code owner) {
super(owner);
}
ConstantInstruction(Code owner, int opcode) {
super(owner, opcode);
}
int getLength() {
switch (getOpcode()) {
case Constants.BIPUSH:
case Constants.LDC:
return super.getLength() + 1;
case Constants.SIPUSH:
case Constants.LDCW:
case Constants.LDC2W:
return super.getLength() + 2;
default:
return super.getLength();
}
}
public int getStackChange() {
String type = getTypeName();
if (double.class.getName().equals(type)
|| long.class.getName().equals(type))
return 2;
return 1;
}
public int getLogicalStackChange() {
return 1;
}
public String getTypeName() {
int opcode = getOpcode();
switch (opcode) {
case Constants.NOP:
return null;
case Constants.ACONSTNULL:
return Object.class.getName();
case Constants.ICONSTM1:
case Constants.ICONST0:
case Constants.ICONST1:
case Constants.ICONST2:
case Constants.ICONST3:
case Constants.ICONST4:
case Constants.ICONST5:
case Constants.BIPUSH:
case Constants.SIPUSH:
return int.class.getName();
case Constants.LCONST0:
case Constants.LCONST1:
return long.class.getName();
case Constants.FCONST0:
case Constants.FCONST1:
case Constants.FCONST2:
return float.class.getName();
case Constants.DCONST0:
case Constants.DCONST1:
return double.class.getName();
}
Entry entry = getPool().getEntry(_arg);
switch (entry.getType()) {
case Entry.UTF8:
case Entry.STRING:
return String.class.getName();
case Entry.INT:
return int.class.getName();
case Entry.FLOAT:
return float.class.getName();
case Entry.LONG:
return long.class.getName();
case Entry.DOUBLE:
return double.class.getName();
case Entry.CLASS:
return Class.class.getName();
default:
return null;
}
}
public TypedInstruction setType(String type) {
throw new UnsupportedOperationException("Use setValue");
}
/**
* Return the value of the constant as its wrapper type, or null if
* not set. Returns class values as the class name.
*/
public Object getValue() {
int opcode = getOpcode();
switch (opcode) {
case Constants.NOP:
case Constants.ACONSTNULL:
return null;
case Constants.ICONSTM1:
case Constants.ICONST0:
case Constants.ICONST1:
case Constants.ICONST2:
case Constants.ICONST3:
case Constants.ICONST4:
case Constants.ICONST5:
return Numbers.valueOf(opcode - Constants.ICONST0);
case Constants.LCONST0:
case Constants.LCONST1:
return Numbers.valueOf((long) (opcode - Constants.LCONST0));
case Constants.FCONST0:
case Constants.FCONST1:
case Constants.FCONST2:
return new Float(opcode - Constants.FCONST0);
case Constants.DCONST0:
case Constants.DCONST1:
return new Double(opcode - Constants.DCONST0);
case Constants.BIPUSH:
case Constants.SIPUSH:
return Numbers.valueOf(_arg);
default:
Entry entry = getPool().getEntry(_arg);
Object val = ((ConstantEntry) entry).getConstant();
if (entry.getType() == Entry.CLASS)
return getProject().getNameCache().getExternalForm((String) val,
false);
return val;
}
}
/**
* Set the constant to the given value. The value should be
* an instance of String, Integer, Long, Double, Float, Class, BCClass, or
* null depending on the constant type. If the given value is not
* supported directly, it will be converted accordingly.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(Object value) {
boolean clsName = false;
if (value instanceof Boolean)
value = Numbers.valueOf((((Boolean) value).booleanValue()) ? 1 : 0);
else if (value instanceof Character)
value = Numbers.valueOf((int) ((Character) value).charValue());
else if (value instanceof Byte)
value = Numbers.valueOf(((Byte) value).intValue());
else if (value instanceof Short)
value = Numbers.valueOf(((Short) value).intValue());
else if (value instanceof Class) {
value = ((Class) value).getName();
clsName = true;
} else if (value instanceof BCClass) {
value = ((BCClass) value).getName();
clsName = true;
} else if (value != null && !(value instanceof Number)
&& !(value instanceof String))
throw new IllegalArgumentException("value = " + value);
calculateOpcode(value, clsName, false);
return this;
}
/**
* Return the string value of this constant, or null if not set.
*/
public String getStringValue() {
return (String) getValue();
}
/**
* Return the int value of this constant, or 0 if not set.
*/
public int getIntValue() {
Object value = getValue();
return (value == null) ? 0 : ((Number) value).intValue();
}
/**
* Return the long value of this constant, or 0 if not set.
*/
public long getLongValue() {
Object value = getValue();
return (value == null) ? 0L : ((Number) value).longValue();
}
/**
* Return the float value of this constant, or 0 if not set.
*/
public float getFloatValue() {
Object value = getValue();
return (value == null) ? 0F : ((Number) value).floatValue();
}
/**
* Return the double value of this constant, or 0 if not set.
*/
public double getDoubleValue() {
Object value = getValue();
return (value == null) ? 0D : ((Number) value).doubleValue();
}
/**
* Return the class value of this constant, or null if not set.
*/
public String getClassNameValue() {
return (String) getValue();
}
/**
* Set this constant to null.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setNull() {
calculateOpcode(null, false, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(String value) {
return setValue(value, false);
}
public ConstantInstruction setValue(String value, boolean clsName) {
calculateOpcode(value, clsName, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(Class value) {
if (value == null)
return setNull();
calculateOpcode(value.getName(), true, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(BCClass value) {
if (value == null)
return setNull();
calculateOpcode(value.getName(), true, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(int value) {
calculateOpcode(Numbers.valueOf(value), false, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(long value) {
calculateOpcode(Numbers.valueOf(value), false, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(float value) {
calculateOpcode(new Float(value), false, false);
return this;
}
/**
* Set the value of this constant.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(double value) {
calculateOpcode(new Double(value), false, false);
return this;
}
/**
* Set the value of this constant; note that this type is converted to int.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(boolean value) {
return setValue((value) ? 1 : 0);
}
/**
* Set the value of this constant; note that this type is converted to int.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(short value) {
return setValue((int) value);
}
/**
* Set the value of this constant; note that this type is converted to int.
*
* @return this instruction, for method chaining
*/
public ConstantInstruction setValue(char value) {
return setValue((int) value);
}
/**
* ConstantInstructions are equal if the const they reference is the same,
* or if the const of either is unset.
*/
public boolean equalsInstruction(Instruction other) {
if (this == other)
return true;
if (!(other instanceof ConstantInstruction))
return false;
ConstantInstruction ci = (ConstantInstruction) other;
Object value = getValue();
Object otherValue = ci.getValue();
if (value == null || otherValue == null)
return true;
if (getTypeName() == null || ci.getTypeName() == null)
return true;
return value.equals(otherValue)
&& getTypeName().equals(ci.getTypeName());
}
public void acceptVisit(BCVisitor visit) {
visit.enterConstantInstruction(this);
visit.exitConstantInstruction(this);
}
void read(Instruction orig) {
super.read(orig);
ConstantInstruction ci = (ConstantInstruction) orig;
calculateOpcode(ci.getValue(),
Class.class.getName().equals(ci.getTypeName()),
ci.getOpcode() == Constants.LDCW);
}
void read(DataInput in) throws IOException {
super.read(in);
switch (getOpcode()) {
case Constants.BIPUSH:
case Constants.LDC:
_arg = in.readUnsignedByte();
break;
case Constants.SIPUSH:
case Constants.LDCW:
case Constants.LDC2W:
_arg = in.readUnsignedShort();
}
}
void write(DataOutput out) throws IOException {
super.write(out);
switch (getOpcode()) {
case Constants.BIPUSH:
case Constants.LDC:
out.writeByte(_arg);
break;
case Constants.SIPUSH:
case Constants.LDCW:
case Constants.LDC2W:
out.writeShort(_arg);
break;
}
}
private void calculateOpcode(Object value, boolean clsName, boolean wide) {
int len = getLength();
_arg = -1;
if (value == null)
setOpcode(Constants.ACONSTNULL);
else if (clsName) {
String name = getProject().getNameCache().getInternalForm((String)
value, false);
_arg = getPool().findClassEntry(name, true);
setOpcode(Constants.LDCW);
} else if (value instanceof Float) {
float floatVal = ((Float) value).floatValue();
if ((floatVal == 0) || (floatVal == 1) || (floatVal == 2))
setOpcode(Constants.FCONST0 + (int) floatVal);
else {
_arg = getPool().findFloatEntry((float) floatVal, true);
setOpcode((_arg > 255 || wide) ? Constants.LDCW
: Constants.LDC);
}
} else if (value instanceof Long) {
long longVal = ((Long) value).longValue();
if (longVal == 0 || longVal == 1)
setOpcode(Constants.LCONST0 + (int) longVal);
else {
_arg = getPool().findLongEntry(longVal, true);
setOpcode(Constants.LDC2W);
}
} else if (value instanceof Double) {
double doubleVal = ((Double) value).doubleValue();
if (doubleVal == 0 || doubleVal == 1)
setOpcode(Constants.DCONST0 + (int) doubleVal);
else {
_arg = getPool().findDoubleEntry(doubleVal, true);
setOpcode(Constants.LDC2W);
}
} else if (value instanceof Integer) {
int intVal = ((Integer) value).intValue();
if (intVal >= -1 && intVal <= 5)
setOpcode(Constants.ICONST0 + intVal);
else if ((intVal >= -(2 << 6)) && (intVal < (2 << 6))) {
setOpcode(Constants.BIPUSH);
_arg = intVal;
} else if (intVal >= -(2 << 14) && intVal < (2 << 14)) {
setOpcode(Constants.SIPUSH);
_arg = intVal;
} else {
_arg = getPool().findIntEntry(intVal, true);
setOpcode((_arg > 255 || wide) ? Constants.LDCW
: Constants.LDC);
}
} else if (value instanceof String) {
_arg = getPool().findStringEntry((String) value, true);
setOpcode((_arg > 255 || wide) ? Constants.LDCW : Constants.LDC);
} else
throw new IllegalArgumentException(String.valueOf(value));
if (len != getLength())
invalidateByteIndexes();
}
}
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