Summary
-------

Remove the `apt` tool, associated API, and documentation from the JDK.


Goals
-----

By removing `apt` from the JDK, annotation processing can finish
transitioning to the superior, standardized JSR 269 API.

The `apt` annotation processing framework is JDK-specific and dates
back to JDK 5.  The functionality of the API was standardized with
JSR 269, which shipped as part of Java SE 6.  In JDK 7, the entirety
of the `apt` API was deprecated.


Non-Goals
---------

Developing automated tooling to convert `apt` annotation processors
to JSR 269 annotation processors is out of scope for this effort.


Motivation
----------

Unlike the JSR 269 API, the `apt` API cannot be updated to model
language features introduced after JDK 5.  Removing `apt` from the JDK
will also ease maintenance of `javac` and related tools.


Description
-----------

Implementing the removal will include removing the affected files from
the JDK 8 `langtools` Mercurial repository as well as supporting
makefile changes.


Testing
-------

Any testing will be limited to verifying the apt command and API are
*not* present.


Risks and Assumptions
---------------------

Subject to the dependency noted below, there are no engineering issues
with excising `apt` from the JDK.  Users of annotation processing will
have ample warning `apt` has been removed so needed migrations can
occur before JDK 8 ships.


Dependences
-----------

Portions of `jaxws` are built on top of apt.  These components need to
be migrated to use the JSR 269 implementation in the JDK before apt
can be removed.


Impact
------

After this change, users of annotation processing will have to use the
JSR 269 annotation processing facility, which has been supported in `javac`
since JDK 6.  Since `apt` is just part of the JDK and not part of Java
SE, there is a looser compatibility contract around this component
than around an API in `java.*` or `javax.*`.  The removal of a command
line tool from the JDK is not unprecedented, but the removal of `apt`
should be clearly described in the release notes and similar
documents.