(Sorry if this is a bit TL, please don't DR though...)
Good we started clearing this up!
Let me start with a recap of the current situation:
The man pages exist in the source code in OpenJDK. During the build, they get
copied to the JRE and JDK image, in the normal OpenJDK build. (Let me remind
you that this is an OpenJDK list, so what we're discussing here is, by default,
OpenJDK.)
In the Oracle JDK, some additional code has been added that actively filters
out the man pages from the image.
The net effect is that the OpenJDK build includes these man pages, while the
Oracle JDK does not.
At some point in time, during JDK 8 I think, Oracle started doing this
filtering. As a consequence, we suggested deleting the man pages. This was, as
I remember it, met by opposition from other parts of the community. It ended up
with the man pages remaining, and a declaration from Oracle that the man pages
will not be updated by Oracle, and that the rest of the community needed to
step up to keep this up to date.
As far as I know, no contributions have been made to the man pages during this
period.
This leaves us at today. That means that if we do nothing, we (meaning the
OpenJDK project) will ship the same man pages as we did in JDK 8. (Note that
the discussion what *Oracle* ships is different, and need to be conducted in a
different forum.)
Since the rest of the community previously preferred to have any man pages,
even if they were out of date, rather than to have none, I presume this still
is the case. It would be good to have some input on this assumption, though,
from e.g. Red Hat.
So, the first decision we need to make is:
1) should we keep the man pages as they are?
2) should we remove them completely?
3) should we keep the man pages and update them?
Unfortunately, option 3 which should have been the winner, is out of the
question due to time constraints.
The default route (doing nothing) is selecting option 1, and so does this
patch. Anyone opting for option 2, need to file a bug to remove the man pages.
My vote is definitely for option 1. It's the rare documentation that's completely up to
date, and in most cases some documentation is better than none. I know I'd be pissed if I
couldn't type "man javac" in my OpenJDK installation on Ubuntu. I acknowledge
that there have been some substantial changes in JDK to some of the central tools, but
most of the tools are unchanged, and even for java and javac, the vast majority of the
options and descriptions still apply.
The second part of the question is, given that option 1 above is followed,
where should the man pages reside in the source tree, and where should it end
up in the output? If option 2 is chosen, the rest of this discussion can be
skipped.
JEP 299 clearly states a place in the source tree for man pages. While it says
that man pages should be in markdown format, it also includes a caveat saying
that actual conversation of the man pages to markdown is a non-goal of the JEP.
From a build perspective, it makes sense to look at all files in the
$module/man directories, and if the file is in markdown, convert it (I have
this code in a sandbox, and I had planned to post that as a follow-up), or if
it's in troff format, just copy it.
So this patch is the first step of the build requirements on man pages as
stated in JEP 299.
Given that we should keep these files, I see no reason not to move them to the
location given by JEP 299. I really hope there is no opposition to this part,
at least.
The final question is about where to store the man pages in the output.
Previously, they have been part of the JDK and JRE images. Since JEP 299 states
that man pages should be part of the docs image, I assume it meant that they
should be removed from the JDK/JRE images, since it does not make sense to have
it in two places.
The ability of jlink to include man pages was news to me. This is not mentioned
in JEP 299, nor used in the current build. I assume this is a remnant from
previous thinking, prior to JEP 299.
Frankly, I'm a bit surprised by the buzz this patch has generated. I think most
of it stems from the confusion between OpenJDK and Oracle JDK, where it has not
been apparent to all Oracle employees that what Oracle ships differs in this
respect from what OpenJDK ships. And once again, this patch is not about what
Oracle will ship, but OpenJDK.
/Magnus
12 maj 2017 kl. 04:57 skrev Mandy Chung <[email protected]>:
On May 11, 2017, at 5:44 PM, Erik Joelsson <[email protected]> wrote:
On 2017-05-11 15:38, Mandy Chung wrote:
Magnus,
I’m surprised to see the man pages are moved to src/$MODULE/share/man
directory. These man pages are not maintained and not updated. It’s agreed
that the man pages are specification for the tools that we should write and
include in the source under src/$MODULE/share/man directory. However, it’s not
intended to move these unmaintained man page to the source.
My quick skimming through JEP 299 led me to think this was indeed the
intention, at least as placeholders until better documentation can be provided.
Jon already clarified. That’s the original intent but had to defer it to JDK
10 due to the time we have.
Related to copying the man pages to the image, man pages should be packaged in
a module (JDK-8167558 [1]). JMOD file has a man page section specific for man
pages. jlink provides an option --no-man-pages to exclude man pages when
creating an image. make/CreateJmods.gmk was modified to include the man pages
in creating JMOD files [1].
The jmods will add man pages if there are any in support/modules_man but I know
of now part of the build process that ever puts man pages in there. The man
pages in the jdk/jre images are still copied into the image using manual
makefile copy in Images.gmk.
Hmm… At that time we might have thought to wait for JEP 299 to do the man
pages work. I added the jmod and jlink mechanism and waited for the man pages
be converted to the source form.
If my memory served well, I tested on OpenJDK build that jdk image has the man
pages. For Oracle build, it does not ship with man pages. Did I remember
correctly? Under what build configuration do we include the man pages in the
image? Maybe it’s not doing what it’s supposed to be??
We currently only copy man pages into the jdk/jre images when building OpenJDK
and not when building OracleJDK.
We have to decide what to do with the man pages for OpenJDK build:
1) copy to jdk/jre image as is.
These man pages are out dated. Copying by default seems not good.
2) a configure option to enable copying man pages. Default no man page.
other options?
Mandy
/Erik
Mandy
[1] https://bugs.openjdk.java.net/browse/JDK-8167558
On May 11, 2017, at 5:56 AM, Magnus Ihse Bursie <[email protected]>
wrote:
In preparation for JDK-8178317, the existing man page troff sources will be
moved to their corresponding modules, according to the layout determined by JEP
299. During the docs build, they will be copied to the man directory in the
docs image, as specified by JEP 299. No markdown conversion will be done for
now, though.
Note that this will only apply to OpenJDK, not the Oracle JDK, which do not ship the man pages from
the OpenJDK repository. (This has not been the case since at least JDK 8.) Also note that the man
pages themselves have not been updated. I did update "JDK 8" to "JDK 9", but I
have made no other changes. Nevertheless, I believe having man pages (even if outdated) is better
for the community than not having man pages.
The jhat and jsadebug tools have been removed in JDK 9, so I removed these man
pages as well.
Prior to this reorganisation, the man pages were duplicated in three
directories, one for each of solaris, linux and bsd. I have verified that for
the remaining man pages, there were no substantial difference between these
versions.
Bug: https://bugs.openjdk.java.net/browse/JDK-8180178
WebRev:
http://cr.openjdk.java.net/~ihse/JDK-8180178-restructure-man-pages/webrev.01
/Magnus
