io.github.dmlloyd.classfile.attribute.CodeAttribute Maven / Gradle / Ivy

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package io.github.dmlloyd.classfile.attribute;

import io.github.dmlloyd.classfile.Attribute;
import io.github.dmlloyd.classfile.CodeModel;
import io.github.dmlloyd.classfile.Label;
import io.github.dmlloyd.classfile.impl.BoundAttribute;
import io.github.dmlloyd.classfile.extras.PreviewFeature;

/**
 * Models the {@code Code} attribute (JVMS {@jvms 4.7.3}), appears on non-native,
 * non-abstract methods and contains the bytecode of the method body.  Delivered
 * as a {@link io.github.dmlloyd.classfile.MethodElement} when traversing the elements of a
 * {@link io.github.dmlloyd.classfile.MethodModel}.
 * 
 * The attribute does not permit multiple instances in a given location.
 * Subsequent occurrence of the attribute takes precedence during the attributed
 * element build or transformation.
 *
 * @since 22
 */
@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
public sealed interface CodeAttribute extends Attribute, CodeModel
        permits BoundAttribute.BoundCodeAttribute {

    /**
     * {@return the maximum size of the local variable table}
     */
    int maxLocals();

    /**
     * {@return the maximum size of the operand stack}
     */
    int maxStack();

    /**
     * {@return The length of the code array in bytes}
     */
    int codeLength();

    /**
     * {@return the bytes (bytecode) of the code array}
     */
    byte[] codeArray();

    /**
     * {@return the position of the {@code label} in the {@link #codeArray codeArray}}
     * @param label a marker for a position within this {@code CodeAttribute}
     * @throws IllegalArgumentException if the {@code label} is not from this attribute
     */
    int labelToBci(Label label);
}