// Copyright (c) Corporation for National Research Initiatives
package org.python.compiler;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
class Label {
int position;
int[] offsets, positions, sizes;
int noffsets;
Code code;
int stack;
public Label(Code code) {
this.code = code;
position = -1;
noffsets = 0;
offsets = new int[4];
positions = new int[4];
sizes = new int[4];
stack = -1;
}
public void fix(byte[] data) throws IOException {
ByteArrayOutputStream array = new ByteArrayOutputStream();
DataOutputStream stream = new DataOutputStream(array);
if (noffsets > 0 && position == -1)
throw new InternalError("position never set for label");
for (int i = 0; i < noffsets; i++) {
//System.out.println("o: "+offsets[i]+", "+position+", "+
// positions[i]);
int off = position - offsets[i];
int p = positions[i];
if (sizes[i] == 2) {
stream.writeShort(off);
} else {
stream.writeInt(off);
}
System.arraycopy(array.toByteArray(), 0, data, p, sizes[i]);
array.reset();
//data[p] = (byte)(off >>> 8);
//data[p+1] = (byte)(off & 0xff00);
}
}
public void setStack(int stack) {
if (this.stack == -1) {
this.stack = stack;
} else {
if (this.stack != stack) {
throw new InternalError("stack sizes don't agree: " + this.stack + ", " + stack);
}
}
}
public int getPosition() {
if (position == -1)
throw new InternalError("position never set for label");
return position;
}
public void setPosition() {
position = code.size();
//code.addLabel(this);
}
public void setBranch(int offset, int size) throws IOException {
if (noffsets >= offsets.length) {
int[] new_offsets = new int[offsets.length * 2];
System.arraycopy(offsets, 0, new_offsets, 0, noffsets);
offsets = new_offsets;
int[] new_positions = new int[positions.length * 2];
System.arraycopy(positions, 0, new_positions, 0, noffsets);
positions = new_positions;
int[] new_sizes = new int[sizes.length * 2];
System.arraycopy(sizes, 0, new_sizes, 0, noffsets);
sizes = new_sizes;
}
positions[noffsets] = code.size();
offsets[noffsets] = offset;
sizes[noffsets] = size;
noffsets = noffsets + 1;
if (size == 2) {
code.code.writeShort(0);
} else {
code.code.writeInt(0);
}
}
}