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Testing class-file attributes generated by Javac

The lack of, or insufficient, capability to create tests for class-file attributes was the impetus behind the effort to ensure javac creates a class-file's attributes completely and correctly. This suggests that even if some attributes are not used by the class-file, all class-files should be generated with a complete set of attributes. There also needs to be a way of testing that the class-files were created correctly, in regards to the file's attributes.

Prior to Java 9, there was no method of testing a class-file's attributes. Running a class and testing the code for anticipated or expected results were the most commonly used method of testing javac generated class-files. This technique falls short of testing to validate the file's attributes.

There are three categories of class-file attributes—attributes used by the JVM, optional attributes, and attributes not used by the JVM.

Attributes used by the JVM include the following:

BootstrapMethods
Code
ConstantValue
Exceptions
StackMapTable

Optional attributes include the following:

Deprecated
LineNumberTable
LocalVariableTable
LocalVariableTypeTable
SourceDebugExtension
SourceFile

Attributes not used by the JVM include the following:

AnnotationDefault
EnclosingMethod
InnerClasses
MethodParameters
RuntimeInvisibleAnnotations
RuntimeInvisibleParameterAnnotations
RuntimeInvisibleTypeAnnotations
RuntimeVisibleAnnotations
RuntimeVisibleParameterAnnotations
RuntimeVisibleTypeAnnotations
Signature
Synthetic