On Thu, 27 May 2021 18:28:13 GMT, Evgeny Mandrikov <go...@openjdk.org> wrote:
>>> > I've updated the code to produce better/more useful LineNumberTable for
>>> > rule switches.
>>>
>>> @lahodaj I re-tested previous example and tested few others. Now everything
>>> seems to be good with `LineNumberTable` entries +1
>>>
>> [...]
>>> Don't know about importance of this, and whether this was expected, but
>>> decided to mention.
>>
>> Look likes a mistake for me, you only need a StackFrame in front of the call
>> to invokedynamic if it's the target of a goto and in your example, there is
>> no guard so no backward goto.
>
>> in your example, there is no guard so no backward goto
>
> @forax btw this example is not about switch pattern matching - it is about
> already existing string switch, where indy not involed 😉
>
>
> void example(java.lang.String);
> descriptor: (Ljava/lang/String;)V
> flags: (0x0000)
> Code:
> stack=2, locals=4, args_size=2
> 0: aload_1
> 1: astore_2
> 2: iconst_m1
> 3: istore_3
> 4: aload_2
> 5: invokevirtual #7 // Method
> java/lang/String.hashCode:()I
> 8: lookupswitch { // 1
> 97: 28
> default: 39
> }
> 28: aload_2
> 29: ldc #13 // String a
> 31: invokevirtual #15 // Method
> java/lang/String.equals:(Ljava/lang/Object;)Z
> 34: ifeq 39
> 37: iconst_0
> 38: istore_3
> 39: iload_3
> 40: lookupswitch { // 1
> 0: 60
> default: 68
> }
> 60: getstatic #19 // Field
> java/lang/System.out:Ljava/io/PrintStream;
> 63: ldc #13 // String a
> 65: invokevirtual #25 // Method
> java/io/PrintStream.println:(Ljava/lang/String;)V
> 68: return
> LineNumberTable:
> line 3: 0
> line 5: 60
> line 7: 68
> StackMapTable: number_of_entries = 5
> frame_type = 253 /* append */
> offset_delta = 4
> locals = [ class java/lang/String, int ]
> frame_type = 23 /* same */
> frame_type = 10 /* same */
> frame_type = 20 /* same */
> frame_type = 249 /* chop */
> offset_delta = 7
@Godin thanks for noticing the unnecessary point in the StackMap! I've limited
the entry to only be present for pattern matching switches, so ordinary
switches should now look as before. Thanks!
-------------
PR: https://git.openjdk.java.net/jdk/pull/3863
