how to tell 2 methods are override-equivalent

[Martin Buchholz]

My ancient script findMissingSince examined the generated javadoc for
various jdk revisions and parsed the resulting html via regexes (despite
http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags
).

Whether using hacky regexes or "proper" tools aware of the java language,
there is a need to compare method signatures.  Erasure-equivalent methods
are the "same" method.

(As always, it would be nice if the resulting code were available to
anyone.)


On Sun, Mar 19, 2017 at 7:13 PM, Hamlin Li <huaming.li at oracle.com> wrote:

> Hi Vicente,
> Thank you for responding, please check the comments inline.
>
> On 2017/3/17 21:08, Vicente Romero wrote:
>
> Hi Hamlin,
>
> How do you obtain m2? I mean at some point it should have been obtained
> from an executable element or similar.
>
> I have a java doclet which scans jdk versions iteratively, m2 was got in
> previous round of run of the tool , then it's stored in a file (for example
> when scan jdk 1.8 source code), then parsed and retrieved from the file
> again (for example when scan jdk 9 source code).
>
> In the worst case you can always generate a simple test case and try to
> compile it for example:
>
> class Test {
>     void getContent(java.lang.Class<?>[] c) {}
>     void getContent(java.lang.Class[] c) {}
> }
>
> this one will fail saying that both methods have the same erasure,
>
> Yes, it should fail.
> In my situation, "getContent(java.lang.Class[] c) {}" is the code in jdk
> 1.8, "getContent(java.lang.Class<?>[] c) {}" is the corresponding code in
> jdk 9. When I scan jdk 9 source code, I need to tell that
> getContent(java.lang.Class<?>[] c) and getContent(java.lang.Class[] c)
> are in fact the same method, rather than 2 different methods.
>
> Thank you
> -Hamlin
>
>
> HTH,
> Vicente
>
> On 03/16/2017 11:15 PM, Hamlin Li wrote:
>
> Hi,
>
> ( I'm not sure if this is the right alias to ask the question, please help
> forward if necessary. )
>
> I have a question about telling whether one method is subsignature of
> another one. My situation is,
>
> 1. there is a TypeElement *t1 *which represents java.net.URL, and a
> ExecutableElement *m1* which represents getContent(java.lang.Class*<?>*[]),
>
>
> 2. there is a String *t2* which is "java.net.URL", and another String *m2
> *which is "getContent(java.lang.Class[])".
>
> The difference between m1 and m2 is that, m1 is an instance of
> ExecutableElement, m2 is an instance of String; there is a wildcard type
> argument in m1.
>
>
> Is there a way to tell whether m1 and m2 are override-equivalent, m2 is
> subsignature of m1?
>
> I suppose I should use javax.lang.model.util.Types.isSubsignature(ExecutableType
> m1, ExecutableType m2), but I don't know how can I convert
> ExecutableElement *m1* and String *m2* to ExecutableType.
>
> Or I'm in wrong direction?
>
>
> Thank you
>
> -Hamlin
>
>
>
>
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