Enum Class ClassFile.StackMapsOption
- All Implemented Interfaces:
- Serializable,- ClassFile.Option,- Comparable<ClassFile.StackMapsOption>,- Constable
- Enclosing interface:
- ClassFile
public static enum ClassFile.StackMapsOption
extends Enum<ClassFile.StackMapsOption>
implements ClassFile.Option
The option describing whether to generate stack maps.  The default is
 
STACK_MAPS_WHEN_REQUIRED to generate stack maps or reuse
 existing ones if compatible.
 
 The StackMapTableAttribute is a derived property from a Code attribute to allow a Java Virtual Machine to perform
 verification in one pass.  Thus, it is not modeled as part of a CodeModel, but computed on-demand instead via stack maps generation.
 
 Stack map generation may fail with an IllegalArgumentException if
 there is unreachable code or legacy
 jump routine
 instructions.  When DROP_STACK_MAPS option is used, users can
 provide their own stack maps by supplying a StackMapTableAttribute
 to a CodeBuilder.
- See Java Virtual Machine Specification:
- 
4.10.1 Verification by Type Checking
- Since:
- 24
- See Also:
- 
Nested Class SummaryNested classes/interfaces declared in class java.lang.EnumEnum.EnumDesc<E extends Enum<E>>
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Enum Constant SummaryEnum ConstantsEnum ConstantDescriptionDo not run stack map generation.Forces running stack map generation.Generate stack maps or reuse existing ones if compatible.
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Method SummaryModifier and TypeMethodDescriptionstatic ClassFile.StackMapsOptionReturns the enum constant of this class with the specified name.static ClassFile.StackMapsOption[]values()Returns an array containing the constants of this enum class, in the order they are declared.
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Enum Constant Details- 
STACK_MAPS_WHEN_REQUIREDGenerate stack maps or reuse existing ones if compatible. Stack maps are present on major versions 50 or above. For these versions,CodeBuildertries to reuse compatible stack maps information if the code array and exception handlers are still compatible after a transformation; otherwise, it runs stack map generation. However, it does not fail fast if the major version is 50, which allows jump subroutine instructions that are incompatible with stack maps to exist in thecodearray.
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GENERATE_STACK_MAPSForces running stack map generation. This runs stack map generation unconditionally and fails fast if the generation fails due to any reason.
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DROP_STACK_MAPSDo not run stack map generation. Users must supply their ownStackMapTableAttributeto aCodeBuilderif the code has branches or exception handlers; otherwise, the generated code will fail verification (JVMS 4.10.1).This option is required for user-supplied StackMapTableAttributeto be respected. Stack maps on an existingCodeattribute can be reused as below with this option:CodeAttribute code = method.findAttribute(Attributes.code()).orElseThrow(); // Note that StackMapTable may be absent, representing code with no branching code.findAttribute(Attributes.stackMapTable()).ifPresent(cob);
 
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Method Details- 
valuesReturns 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
 
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valueOfReturns 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
 
 
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