dexlib2/src/main/java/org/jf/dexlib2/builder/BuilderOffsetInstruction.java

/*
 * Copyright 2013, Google Inc.
 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 */

package org.jf.dexlib2.builder;

import org.jf.dexlib2.Opcode;
import org.jf.dexlib2.iface.instruction.OffsetInstruction;

import javax.annotation.Nonnull;

public abstract class BuilderOffsetInstruction extends BuilderInstruction implements OffsetInstruction {
    @Nonnull
    protected final Label target;

    public BuilderOffsetInstruction(@Nonnull Opcode opcode,
                                    @Nonnull Label target) {
        super(opcode);
        this.target = target;
    }

    @Override public int getCodeOffset() {
        int codeOffset = internalGetCodeOffset();
        if ((this.getCodeUnits() == 1 && (codeOffset < Byte.MIN_VALUE || codeOffset > Byte.MAX_VALUE)) ||
            (this.getCodeUnits() == 2 && (codeOffset < Short.MIN_VALUE || codeOffset > Short.MAX_VALUE))) {
            throw new IllegalStateException("Target is out of range");
        }
        return codeOffset;
    }


    int internalGetCodeOffset() {
        return target.getCodeAddress() - this.getLocation().getCodeAddress();
    }

    @Nonnull
    public Label getTarget() {
        return target;
    }
}