RFR: 8177280: @see {@link} syntax should allow generic types

Fri Apr 17 01:53:04 UTC 2020

Generally excellent. Thanks for finally addressing this long-standing wish.

I did some research (archaeology) on the fuzzyMatch issue. It looks like 
a lot of the code in this area was imported from the old JDK 8-era 
standard doclet, as evidenced by a number of now-obsolete/broken 
references like:

@see com.sun.tools.javadoc.ClassDocImpl

fuzzyMatch itself seems to have been new in the JavacTrees code, 
superseding some equally fuzzy code in the old doclet, which was not 
appropriate to import.  Anyway, we moved all this analysis onto a better 
foundation, so I'm pleased to see the old fuzzy code go away. You might 
want to consider removing the broken/obsolete `@see` references, 
although in this case they were actually useful to point back to the 
origin of the code, in JDK 8.

In LinkInfoImpl, I guess VARIABLE_ELEMENT_COPY was unused, but I guess I 
was surprised that a couple of other _COPY names were not deleted, 
presumably because they were used.  Anyway, it's the difference in 
treatment that I find curious.

Tiny Nit:  In CommentHelper:196, `doctrees` would be better written as 
`docTrees`.

This work probably merits a Release Note.

-- Jon

On 4/8/20 9:21 AM, Hannes Wallnoefer wrote:
> Jon,
>
> I uploaded a new webrev for this issue:
>
> http://cr.openjdk.java.net/~hannesw/8177280/webrev.04/
>
> Changes include:
>
>  - updated test to match changes in HTML/CSS
>  - added @since 15 tag to new DocTrees method
>  - allow parameterised types in signatures of method links
>
> The last item requires a bit more explanation.
>
> It is now possible to link to an executable member specifying 
> parameterised types in the signature, e.g.:
>
>  @see #getItem(List<String>,int)
>
> In contrast to links to parameterized types which generate a link to 
> each type component the member link will generate a single link to the 
> method with the full signature as link text. This is consistent with 
> the current behaviour of @see/@link method linking where parameter 
> types are not separate links but part of the main link.
>
> The support this feature I slightly changed the implementation of 
> private #hasParameterTypes method in JavacTrees to first compare the 
> exact parameter types to a member’s signature before comparing the 
> erased types.
>
> It is possible to  specify subtypes in the reference signature, i.e. a 
> method with parameter (? extends Number) can be linked with the exact 
> declared signature or with valid subtypes such as (Integer). I’m not 
> sure if this is desired, but it seems reasonable and potentially 
> useful to me.
>
> I also removed the fuzzyMatch code in JavacTrees signature comparison. 
> The fuzzyMatch method allowed to use erraneous types such as 
> List<NonExistingClass> in signature lookups. I’m not totally whether 
> some of the behaviour in fuzzyMatch is still desired, but  it was very 
> old code and removal didn’t trigger any test failures.
>
> Hannes
>
>
>> Am 03.03.2020 um 22:54 schrieb Jonathan Gibbons 
>> <jonathan.gibbons at oracle.com <mailto:jonathan.gibbons at oracle.com>>:
>>
>> The new method on DocTrees does not have @since and needs a CSR.
>>
>> I ran the new test to confirm all parts of the link. Nice, although 
>> there are lots of "external link" icons.
>>
>> The test has worn out a bit, because of independent changes. I sent 
>> you (separately) a patchy for the new test. With that patch, the test 
>> works for me.
>>
>> OK to push if you patch the test and when you have got the 
>> appropriate CSR approvals.
>>
>> -- Jon
>>
>>
>> On 02/27/2020 02:56 AM, Hannes Wallnöfer wrote:
>>> Thanks for the review, Jon.
>>>
>>> New webrev: http://cr.openjdk.java.net/~hannesw/8177280/webrev.03/
>>>
>>> Comments inline below.
>>>
>>>> Am 25.02.2020 um 00:11 schrieb Jonathan Gibbons 
>>>> <jonathan.gibbons at oracle.com <mailto:jonathan.gibbons at oracle.com>>:
>>>>
>>>> HtmlDocletWriter:1044
>>>>
>>>> Changing RawHtml to StringContent is a significant behavioral 
>>>> change. It's not explicitly stated in the doc comment spec whether 
>>>> the text may contain HTML, but it is reasonable to infer from the 
>>>> descriptions of {@code} and {@literal} that it may be HTML content. 
>>>>  Is this change necessary?
>>> You are right, that change was mostly driven by personal preference, 
>>> which is not a good guideline.
>>>
>>> I reversed it in the new webrev.
>>>
>>>> CommentHelper ... clever changes, I think ;-)
>>>>
>>>> In the new test, the direct/explicit use of 
>>>> https://docs.oracle.com/en/java/javase/12/docs/api/ may cause 
>>>> issues later, in that "sanity scripts" may discover the string and 
>>>> wonder if it is an out of date reference. At a minimum, the use of 
>>>> the URL should be significantly commented in the test.  But, 
>>>> despite the comment on the `testValidLinks` method, I don't think 
>>>> it actually checks that the links exist (as compared to 404-Not 
>>>> Found).  Since you are using -linkoffline, it may be sufficient to 
>>>> just do a global replace of
>>>>
>>>> https://docs.oracle.com/en/java/javase/12/docs/api
>>>>
>>>> to
>>>>
>>>> http://example.com/docs/api
>>>>
>>>> or something like that.
>>>
>>> I replaced the URLs as suggested, indeed the test is passing.
>>>
>>> Hannes
>>>
>>>> -- Jon
>>>>
>>>> On 02/18/2020 03:26 AM, Hannes Wallnöfer wrote:
>>>>> I have updated the patch to recent changes in CommentHelper, no 
>>>>> changes otherwise.
>>>>>
>>>>> http://cr.openjdk.java.net/~hannesw/8177280/webrev.01/
>>>>>
>>>>> Hannes
>>>>>
>>>>>> Am 07.02.2020 um 19:34 schrieb Hannes Wallnöfer 
>>>>>> <hannes.wallnoefer at oracle.com>:
>>>>>>
>>>>>> Please review:
>>>>>>
>>>>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8177280
>>>>>> Webrev: http://cr.openjdk.java.net/~hannesw/8177280/webrev.00/
>>>>>>
>>>>>> As I said previously there are some things in this patch I’m 
>>>>>> unsure or not quite happy about.
>>>>>>
>>>>>> Some notes:
>>>>>>
>>>>>> - While the implementation of the new DocTrees method is quite 
>>>>>> simple, I’m not sure if I should install a new 
>>>>>> Log.DeferredDiagnosticHandler for the runtime of the method, like 
>>>>>> the attributeDocReference method in the same class does.
>>>>>>
>>>>>> - In HtmlDocletWriter.seeTagToContent I changed the handling of 
>>>>>> the tag text to escape HTML characters if no label is specified. 
>>>>>> This causes „<„ and „>“ to be displayed in the browser instead of 
>>>>>> being interpreted as HTML tag if a generic link target can’t be 
>>>>>> resolved. This is potentially problematic since @see and @link 
>>>>>> can contain plain HTML content, but I think it’s ok since those 
>>>>>> cases are handled further up in HtmlDocletWriter.seeTagToContent.
>>>>>>
>>>>>> - That same method in HtmlDocletWriter contained some never-used 
>>>>>> code (dependent on the BaseConfiguration.backwardCompatibility 
>>>>>> flag which is always true) to use the fully qualified class name 
>>>>>> for links in some cases. I removed that code and the field in 
>>>>>> BaseConfiguration since it adds to that already long-winding method.
>>>>>>
>>>>>> - Setting the label on a LinkInfoImpl basically disables 
>>>>>> rendering of type arguments. While I understand the rationale 
>>>>>> behind this, it might still be useful to set the label for the 
>>>>>> main link of a generic type. I’ve tried to remove the 
>>>>>> restriction, but ran into a lot of problems (i.e. failing tests) 
>>>>>> in other places. Since the current behaviour does what we need I 
>>>>>> decided to not change this.
>>>>>>
>>>>>> - There was a potential infinite recursion in 
>>>>>> LinkFactoryImpl.getTypeParameterLinks caused by following the 
>>>>>> type parameters of linkInfo.typeElement when linkInfo.type is 
>>>>>> set. The problem was that linkInfo.typeElement may be set to the 
>>>>>> owner of linkInfo.type, and the solution is to only follow that 
>>>>>> path if linkInfo.type is null.
>>>>>>
>>>>>> - I removed two unused LinkInfo Kind enum values.
>>>>>>
>>>>>> - I CommentHelper there were previously two and now three 
>>>>>> Visitors to extract ReferenceTrees, so I added a common base 
>>>>>> class called ReferenceDocTreeVisitor.
>>>>>>
>>>>>> - As an completely unrelated cleanup I removed the unused javafx 
>>>>>> field in IndexBuilder.
>>>>>>
>>>>>> Thanks,
>>>>>> Hannes
>>
>
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