Interface DiscontinuedInstruction.RetInstruction

All Superinterfaces:: ClassFileElement, CodeElement, DiscontinuedInstruction, Instruction

Enclosing interface:: DiscontinuedInstruction

public static sealed interface DiscontinuedInstruction.RetInstruction extends DiscontinuedInstruction

Models return from subroutine instructions discontinued from the


code

array of a Code attribute since class file major version 51 (JVMS Â§4.9.1). Corresponding opcodes have a kind of Opcode.Kind.DISCONTINUED_RET. Delivered as a CodeElement when traversing the elements of a CodeModel.

A return from subroutine instruction is composite:

RetInstruction(int slot)

where slot must be u2.

astore series of instructions store a returnAddress value to a local variable slot, making the slot usable by a return from subroutine instruction.

API Note:

Return from subroutine instructions are discontinued to enforce verification by type checking (JVMS Â§4.10.1) using the StackMapTable attribute.

See Java Virtual Machine Specification:

6.5.ret ret

Since:

See Also:

Nested Class Summary

Nested classes/interfaces declared in interface DiscontinuedInstruction

DiscontinuedInstruction.JsrInstruction, DiscontinuedInstruction.RetInstruction

Modifier and Type	Interface	Description
`static interface`	`DiscontinuedInstruction.JsrInstruction`	Models jump subroutine instructions discontinued from the `code` array of a `Code` attribute since class file major version 51 (JVMS Â§4.9.1).
`static interface`	`DiscontinuedInstruction.RetInstruction`	Models return from subroutine instructions discontinued from the `code` array of a `Code` attribute since class file major version 51 (JVMS Â§4.9.1).

Method Summary

Modifier and Type	Method	Description
`static DiscontinuedInstruction.RetInstruction`	`of(int slot)`	Returns a return from subroutine instruction.
`static DiscontinuedInstruction.RetInstruction`	`of(Opcode op, int slot)`	Returns a return from subroutine instruction.
`int`	`slot()`	Returns the local variable slot with return address.

Methods declared in interface Instruction

opcode, sizeInBytes

Modifier and Type	Method	Description
`Opcode`	`opcode()`	Returns the operation of this instruction.
`int`	`sizeInBytes()`	Returns the size in bytes of this instruction.

Method Details

slot

int slot()

Returns the local variable slot with return address. It is a u2 value.

Returns:: the local variable slot with return address

of

static DiscontinuedInstruction.RetInstruction of(Opcode op, int slot)

Returns a return from subroutine instruction.

slot must be u1 for ret, or u2 for wide ret.

API Note:: The explicit op argument allows creating wide ret instructions with slot in the range of regular ret instructions.
Parameters:: op - the opcode for the specific type of return from subroutine instruction, which must be of kind Opcode.Kind.DISCONTINUED_RET; slot - the local variable slot to load return address from
Returns:: a return from subroutine instruction
Throws:: IllegalArgumentException - if the opcode kind is not Opcode.Kind.DISCONTINUED_RET or if slot is out of range

of

static DiscontinuedInstruction.RetInstruction of(int slot)

Returns a return from subroutine instruction.

slot must be u2.

Parameters:: slot - the local variable slot to load return address from
Returns:: a return from subroutine instruction
Throws:: IllegalArgumentException - if slot is not u2

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