Interface TypeCheckInstruction

All Superinterfaces:: ClassFileElement, CodeElement, Instruction

public sealed interface TypeCheckInstruction extends Instruction

Models an instanceof or a checkcast instruction in the code array of a Code attribute. Corresponding opcodes have a kind of Opcode.Kind.TYPE_CHECK. Delivered as a CodeElement when traversing the elements of a CodeModel.

An instanceof checks the type and pushes an integer to the operand stack. A checkcast checks the type and throws a ClassCastException if the check fails. instanceof treat the null reference as a failure, while checkcast treat the null reference as a success.

A type check instruction is composite:

TypeCheckInstruction(
    Opcode opcode,
    ClassEntry type
)

Since:: 24

Method Summary

Modifier and Type	Method	Description
`static TypeCheckInstruction`	`of(Opcode op, ClassEntry type)`	Returns a type check instruction.
`static TypeCheckInstruction`	`of(Opcode op, ClassDesc type)`	Returns a type check instruction.
`ClassEntry`	`type()`	Returns the type against which the instruction checks.

Methods declared in interface Instruction

opcode, sizeInBytes

Method Details

type

ClassEntry type()

Returns the type against which the instruction checks.

Returns:: the type against which the instruction checks

of

static TypeCheckInstruction of(Opcode op, ClassEntry type)

Returns a type check instruction.

Parameters:: op - the opcode for the specific type of type check instruction, which must be of kind Opcode.Kind.TYPE_CHECK; type - the type against which to check or cast
Returns:: a type check instruction
Throws:: IllegalArgumentException - if the opcode kind is not Opcode.Kind.TYPE_CHECK

of

static TypeCheckInstruction of(Opcode op, ClassDesc type)

Returns a type check instruction.

Parameters:: op - the opcode for the specific type of type check instruction, which must be of kind Opcode.Kind.TYPE_CHECK; type - the type against which to check or cast
Returns:: a type check instruction
Throws:: IllegalArgumentException - if the opcode kind is not Opcode.Kind.TYPE_CHECK, or if type is primitive

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https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/classfile/instruction/TypeCheckInstruction.html