jdk/src/java.base/share/classes/java/lang/classfile/instruction/InvokeInstruction.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 * accompanied this code).
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package java.lang.classfile.instruction;

import java.lang.constant.MethodTypeDesc;

import java.lang.classfile.CodeElement;
import java.lang.classfile.CodeModel;
import java.lang.classfile.constantpool.ClassEntry;
import java.lang.classfile.Instruction;
import java.lang.classfile.Opcode;
import java.lang.classfile.constantpool.InterfaceMethodRefEntry;
import java.lang.classfile.constantpool.MemberRefEntry;
import java.lang.classfile.constantpool.MethodRefEntry;
import java.lang.classfile.constantpool.NameAndTypeEntry;
import java.lang.classfile.constantpool.Utf8Entry;
import jdk.internal.classfile.impl.AbstractInstruction;
import jdk.internal.classfile.impl.TemporaryConstantPool;
import jdk.internal.classfile.impl.Util;
import jdk.internal.javac.PreviewFeature;

/**
 * Models a method invocation instruction in the {@code code} array of a {@code
 * Code} attribute, other than {@code invokedynamic}.  Corresponding opcodes
 * will have a {@code kind} of {@link Opcode.Kind#INVOKE}.  Delivered as a
 * {@link CodeElement} when traversing the elements of a {@link CodeModel}.
 *
 * @since 22
 */
@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
public sealed interface InvokeInstruction extends Instruction
        permits AbstractInstruction.BoundInvokeInterfaceInstruction, AbstractInstruction.BoundInvokeInstruction, AbstractInstruction.UnboundInvokeInstruction {
    /**
     * {@return the {@link MethodRefEntry} or {@link InterfaceMethodRefEntry}
     * constant described by this instruction}
     */
    MemberRefEntry method();

    /**
     * {@return whether the class holding the method is an interface}
     */
    boolean isInterface();

    /**
     * {@return the {@code count} value of an {@code invokeinterface} instruction, as defined in {@jvms 6.5}
     * or {@code 0} for {@code invokespecial}, {@code invokestatic} and {@code invokevirtual} instructions}
     */
    int count();

    /**
     * {@return the class holding the method}
     */
    default ClassEntry owner() {
        return method().owner();
    }

    /**
     * {@return the name of the method}
     */
    default Utf8Entry name() {
        return method().nameAndType().name();
    }

    /**
     * {@return the method descriptor of the method}
     */
    default Utf8Entry type() {
        return method().nameAndType().type();
    }

    /**
     * {@return a symbolic descriptor for the method type}
     */
    default MethodTypeDesc typeSymbol() {
        return Util.methodTypeSymbol(method().nameAndType());
    }


    /**
     * {@return an invocation instruction}
     *
     * @param op the opcode for the specific type of invocation instruction,
     *           which must be of kind {@link Opcode.Kind#INVOKE}
     * @param method a constant pool entry describing the method
     */
    static InvokeInstruction of(Opcode op, MemberRefEntry method) {
        Util.checkKind(op, Opcode.Kind.INVOKE);
        return new AbstractInstruction.UnboundInvokeInstruction(op, method);
    }

    /**
     * {@return an invocation instruction}
     *
     * @param op the opcode for the specific type of invocation instruction,
     *           which must be of kind {@link Opcode.Kind#INVOKE}
     * @param owner the class holding the method
     * @param name the name of the method
     * @param type the method descriptor
     * @param isInterface whether the class holding the method is an interface
     */
    static InvokeInstruction of(Opcode op,
                                ClassEntry owner,
                                Utf8Entry name,
                                Utf8Entry type,
                                boolean isInterface) {
        return of(op, owner, TemporaryConstantPool.INSTANCE.nameAndTypeEntry(name, type), isInterface);
    }

    /**
     * {@return an invocation instruction}
     *
     * @param op the opcode for the specific type of invocation instruction,
     *           which must be of kind {@link Opcode.Kind#INVOKE}
     * @param owner the class holding the method
     * @param nameAndType the name and type of the method
     * @param isInterface whether the class holding the method is an interface
     */
    static InvokeInstruction of(Opcode op,
                                ClassEntry owner,
                                NameAndTypeEntry nameAndType,
                                boolean isInterface) {
        return of(op, isInterface
                      ? TemporaryConstantPool.INSTANCE.interfaceMethodRefEntry(owner, nameAndType)
                      : TemporaryConstantPool.INSTANCE.methodRefEntry(owner, nameAndType));
    }
}