[ 
https://issues.apache.org/jira/browse/GROOVY-8242?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16115748#comment-16115748
 ] 

Paul King edited comment on GROOVY-8242 at 8/6/17 10:37 AM:
------------------------------------------------------------

Just for historical reference, I don't believe the Groovy compiler will 
complain for all cases where an annotation attribute has no default and is not 
supplied with one when not used. There are several cases:

# If the annotation and usage are both Groovy/same source unit I think you will 
normally see (for the {{value}} annotation attribute as an example):
{code}
No explicit/default value found for annotation attribute 'value' in 
@MyAnnotation
{code}
# If the annotation is Java/pre-compiled and it has SOURCE retention, Groovy 
will keep quiet.
# If the annotation is Java/pre-compiled and it has RUNTIME retention you will 
see the JVM complain:
{code}
java.lang.annotation.IncompleteAnnotationException: MyAnnotation missing 
element value
{code}

I suspect that at least the last of these, case (3), is a bug. I presume in 
earlier versions of the JVM and/or ASM libraries reading an annotation for the 
Java/pre-compiled case with no default value triggered the same check as for 
Groovy above, case (1),  but now it yields a {{ReturnStatement}} containing 
{{null}} as the return value and this avoids detection. Probably the second is 
also a bug provided annotation processing is finished which I think will be 
true since the mandatory attribute check is done during classgen.

In any case, it doesn't affect this issue. I.e. the issue is valid and PR good. 
I'll create an additional issue to track this.


was (Author: paulk):
Just for historical reference, I don't believe the Groovy compiler will 
complain for all cases where an annotation attribute has no default and is not 
supplied with one when not used. There are several cases:

# If the annotation and usage are both Groovy/same source unit I think you will 
normally see (for the {{value}} annotation attribute as an example):
{code}
No explicit/default value found for annotation attribute 'value' in 
@MyAnnotation
{code}
# If the annotation is Java/pre-compiled and it has SOURCE retention, Groovy 
will keep quiet.
# If the annotation is Java/pre-compiled and it has RUNTIME retention you will 
see the JVM complain:
{code}
java.lang.annotation.IncompleteAnnotationException: MyAnnotation missing 
element value
{code}

I suspect that at least the last of these, case (3), is a bug. I presume in 
earlier versions of the JVM and/or ASM libraries reading a Java annotation with 
no default value triggered the same check as for Groovy above, case (1),  but 
now it yields a {{ReturnStatement}} containing {{null}} as the return value and 
this avoids detection. Probably the second is also a bug provided annotation 
processing is finished which I think will be true since the mandatory attribute 
check is done during classgen.

In any case, it doesn't affect this issue. I.e. the issue is valid and PR good. 
I'll create an additional issue to track this.

> Javadoc for Newify is missing some attribute values
> ---------------------------------------------------
>
>                 Key: GROOVY-8242
>                 URL: https://issues.apache.org/jira/browse/GROOVY-8242
>             Project: Groovy
>          Issue Type: Bug
>            Reporter: Eric Milles
>            Assignee: John Wagenleitner
>            Priority: Minor
>             Fix For: 2.4.13
>
>
> I was looking at thw Newify AST transform.  Some of the Javadoc appears 
> incorrect since the annotation requires a value.
> {code}
>  * or this ("Ruby-style"):
>  * <pre>
>  * {@code @Newify} class MyTreeProcessor {  --  Is this supposed to be 
> @Newify([Tree,Leaf])?
>  *     def myTree = Tree.new(Tree.new(Leaf.new("A"), Leaf.new("B")), 
> Leaf.new("C"))
>  *     def process() { ... }
>  * }
>  * </pre>
> {code}
> {code}
>  * An example showing how to use the annotation at different levels:
>  * <pre>
>  * {@code @Newify(auto=false, value=Foo)}
>  * class Main {
>  *     {@code @Newify} // turn auto on for field  --  Is this supposed to be 
> @Newify(BigInteger)?
>  *     def field1 = java.math.BigInteger.new(42)
>  *     def field2, field3, field4
>  *
>  *     {@code @Newify(Bar)}
>  *     def process() {
>  *         field2 = Bar("my bar")
>  *     }
>  *
>  *     {@code @Newify(Baz)}
>  *     Main() {
>  *         field3 = Foo("my foo")
>  *         field4 = Baz("my baz")
>  *     }
>  * }
>  * </pre>
> {code}



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Reply via email to