No handling for non-class annotations

[SilverAndro]

Per https://docs.oracle.com/javase/specs/jvms/se21/html/jvms-4.html#jvms-4.7.16:

type_index
The value of the type_index item must be a valid index into the constant_pool table. The constant_pool entry at that index must be a CONSTANT_Utf8_info structure (§4.4.7) representing a field descriptor (§4.3.2). The field descriptor denotes the type of the annotation represented by this annotation structure.

I don't believe this is possible from java, however it is possible to create and load a class that uses arrays or primitives as an annotation type.

javap manages to handle this by expanding it to the primitive type:

javap output

Classfile PrimitiveAnnotations.class
  Last modified Mar 9, 2024; size 391 bytes
  SHA-256 checksum 13cd127eecea39c43cc4c134ff1370934e77a071f2b768d2184c0f264dd04f97
public class PrimitiveAnnotations
  minor version: 0
  major version: 52
  flags: (0x0001) ACC_PUBLIC
  this_class: #2                          // PrimitiveAnnotations
  super_class: #4                         // java/lang/Object
  interfaces: 0, fields: 0, methods: 1, attributes: 1
Constant pool:
   #1 = Utf8               PrimitiveAnnotations
   #2 = Class              #1             // PrimitiveAnnotations
   #3 = Utf8               java/lang/Object
   #4 = Class              #3             // java/lang/Object
   #5 = Utf8               Z
   #6 = Utf8               [I
   #7 = Utf8               C
   #8 = Utf8               s
   #9 = Integer            3
  #10 = Utf8               [[D
  #11 = Integer            -1
  #12 = Utf8               main
  #13 = Utf8               ([Ljava/lang/String;)V
  #14 = Utf8               java/lang/System
  #15 = Class              #14            // java/lang/System
  #16 = Utf8               out
  #17 = Utf8               Ljava/io/PrintStream;
  #18 = NameAndType        #16:#17        // out:Ljava/io/PrintStream;
  #19 = Fieldref           #15.#18        // java/lang/System.out:Ljava/io/PrintStream;
  #20 = Utf8               Hello, world!
  #21 = String             #20            // Hello, world!
  #22 = Utf8               java/io/PrintStream
  #23 = Class              #22            // java/io/PrintStream
  #24 = Utf8               println
  #25 = Utf8               (Ljava/lang/String;)V
  #26 = NameAndType        #24:#25        // println:(Ljava/lang/String;)V
  #27 = Methodref          #23.#26        // java/io/PrintStream.println:(Ljava/lang/String;)V
  #28 = Utf8               Code
  #29 = Utf8               RuntimeVisibleAnnotations
{
  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: getstatic     #19                 // Field java/lang/System.out:Ljava/io/PrintStream;
         3: ldc           #21                 // String Hello, world!
         5: invokevirtual #27                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
         8: return
}
RuntimeVisibleAnnotations:
  0: #5()
    boolean
  1: #6()
    int[]
  2: #7(#8=I#9)
    char(
      s=3
    )
  3: #10(#8=I#11)
    double[][](
      s=-1
    )

However vineflower currently emits the descriptor directly without comment, likely causing issues or confusion in obfuscated environments:

vineflower output (1.9.3)

@Z
@I
@C(
   s = 3
)
@D(
   s = -1
)
public class PrimitiveAnnotations {
   public static void main(String[] var0) {
      System.out.println("Hello, world!");
   }
}

PrimitiveAnnotations.zip