src/java.base/share/classes/java/lang/classfile/instruction/StackInstruction.java

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package java.lang.classfile.instruction;

import java.lang.classfile.CodeElement;
import java.lang.classfile.CodeModel;
import java.lang.classfile.Instruction;
import java.lang.classfile.Opcode;

import jdk.internal.classfile.impl.AbstractInstruction;
import jdk.internal.classfile.impl.Util;

/**
 * Models a stack manipulation instruction in the {@code code} array of a
 * {@code Code} attribute.  Corresponding opcodes have a {@linkplain Opcode#kind() kind} of
 * {@link Opcode.Kind#STACK}.  Delivered as a {@link CodeElement} when
 * traversing the elements of a {@link CodeModel}.
 * <p>
 * A stack manipulation instruction is composite:
 * {@snippet lang=text :
 * // @link substring="StackInstruction" target="#of" :
 * StackInstruction(Opcode opcode) // @link substring="opcode" target="#opcode()"
 * }
 *
 * @see Opcode.Kind#STACK
 * @since 24
 */
public sealed interface StackInstruction extends Instruction
        permits AbstractInstruction.UnboundStackInstruction {

    /**
     * {@return a stack manipulation instruction}
     *
     * @param op the opcode for the specific type of stack instruction,
     *           which must be of kind {@link Opcode.Kind#STACK}
     * @throws IllegalArgumentException if the opcode kind is not
     *         {@link Opcode.Kind#STACK}.
     */
    static StackInstruction of(Opcode op) {
        Util.checkKind(op, Opcode.Kind.STACK);
        return new AbstractInstruction.UnboundStackInstruction(op);
    }
}