Enum Class ClassFile.ShortJumpsOption

java.lang.Object

java.lang.Enum<ClassFile.ShortJumpsOption>

java.lang.classfile.ClassFile.ShortJumpsOption

All Implemented Interfaces:

Serializable, ClassFile.Option, Comparable<ClassFile.ShortJumpsOption>, Constable

Enclosing interface:

ClassFile

public static enum ClassFile.ShortJumpsOption
extends Enum<ClassFile.ShortJumpsOption>
implements ClassFile.Option

The option describing whether to automatically rewrite short jumps to equivalent instructions when necessary. The default is FIX_SHORT_JUMPS to automatically rewrite.

Due to physical restrictions, some types of instructions cannot encode certain jump targets with bci offsets less than -32768 or greater than 32767, as they use a s2 to encode such an offset. (The maximum length of the code array is 65535.) These types of instructions are called "short jumps".

Disabling rewrite can ensure the physical accuracy of a generated class file and avoid the overhead from a failed first attempt for overflowing forward jumps in some cases, if the generated class file is stable.

Since:

24

See Also:

• BranchInstruction
• DiscontinuedInstruction.JsrInstruction

Nested Class Summary

Nested classes/interfaces declared in class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
FAIL_ON_SHORT_JUMPS	Fail with an IllegalArgumentException if short jump overflows.
FIX_SHORT_JUMPS	Automatically convert short jumps to long when necessary.

Method Summary

Modifier and Type	Method	Description
static ClassFile.ShortJumpsOption	valueOf(String name)	Returns the enum constant of this class with the specified name.
static ClassFile.ShortJumpsOption[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods declared in class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods declared in class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

FIX_SHORT_JUMPS

public static final ClassFile.ShortJumpsOption FIX_SHORT_JUMPS

Automatically convert short jumps to long when necessary.

For an invalid instruction model, a CodeBuilder may generate another or a few other instructions to accomplish the same effect.

FAIL_ON_SHORT_JUMPS

public static final ClassFile.ShortJumpsOption FAIL_ON_SHORT_JUMPS

Fail with an IllegalArgumentException if short jump overflows.

This is useful to ensure the physical accuracy of a generated class file and avoids the overhead from a failed first attempt for overflowing forward jumps in some cases.

Method Details

values

public static ClassFile.ShortJumpsOption[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static ClassFile.ShortJumpsOption valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null