Re: misc/54581: Issues building NetBSD-9 under NetBSD-5.2

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR misc/54581; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: Brian Buhrow <buhrow%nfbcal.org@localhost>
Cc: gnats-bugs%netbsd.org@localhost, misc-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: misc/54581: Issues building NetBSD-9 under NetBSD-5.2
Date: Tue, 01 Oct 2019 12:34:03 +0700

     Date:        Mon, 30 Sep 2019 13:54:15 -0700
     From:        Brian Buhrow <buhrow%nfbcal.org@localhost>
     Message-ID:  <201909302054.x8UKsFdF018121%lothlorien.nfbcal.org@localhost>
 
   | 	hello Robert.  In continuing to try and build netbsd-9 under
   | NetBSD-5.2, I've run into one of these compiler options that gcc 4.1
   | doesn't like and which you committed about a year ago to the tree.
 
 For that one I am fairly sure that I was just copying the same thing
 that was done for a similar problem in another file.
 
 But for these -Wno-xxx options, in general, they are needed whenever
 the compiler implements the -Wxxx option (which the build's -Wall would
 turn on) - if the compiler is old enough to not have that option, then
 turning it off (which it also doesn't recognise) isn't going to work.
 
 This kind of thing can be handled in the Makefile with a test on the
 gcc version being used, if we can find out which gcc version introduced
 the relevant option - and only include the -Wno-xxx for versions of gcc
 that are not older than the version where the option appeared.
 
 But I am not sure it is really worth it - that is, even with these band
 aids, which could be done with no worse effects than more clutter in the
 Makefiles - I am not sure you're going to be able to get a NetBSD 5 gcc to
 build -9 or HEAD.
 
 What you should do is simply remove any options like this from your source
 files, when the compiler objects (comment them out with an easy pattern
 to grep for later, like "#XYZ#" or something) and see if simply doing that
 (as many times as is needed) is enough to get the build to complete.
 
 If it is, do a complete recursive grep through the source tree, looking
 for that pattern, so we know everywhere that would need to be changed, and
 then we can see if it is worth doing this in HEAD, and requesting a pullup
 to -9.
 
 kre