Re: [PATCH] configure: add --disable-fix-includes

["Martin Liška" <mliska@suse.cz>]

On 2/4/22 14:30, Jakub Jelinek via Gcc-patches wrote:
> On Fri, Feb 04, 2022 at 02:25:17PM +0100, Richard Biener via Gcc-patches wrote:
>>> Besides, have you actually run a regtest with that option?  I'm asking
>>> because even on Ubuntu 20.04 fixincludes drops in it's own <limits.h>.
>>> You need to check that dropping that is actually safe.
>>
>> limits.h and syslimits.h are the only include-fixed we "ship" in our
>> packages.  Not sure if they are really required though.
> 
> We don't ship any include-fixed headers in Fedora/RHEL.
> If there is an important need for fixing, it should be in Linux
> distributions fixed by actually fixing the headers in their corresponding
> packages, making modified copies of headers at gcc build time and overriding
> through that headers from other packages that can change doesn't really work
> properly when those headers ever change.  I know we could install the
> fixincludes tool and trigger running it whenever any of such headers change
> in other packages, but that is very expensive for very little gain.

I fully agree with the suggested approach! I've also noticed the script makes
modifications in comments (that are unnecessary), plus it effectively breaks
header files for things like:

$ diff /usr/lib64/gcc/aarch64-suse-linux/11/include-fixed/bits/unistd_ext.h /usr/aarch64-suse-linux/sys-root/usr/include/bits/unistd_ext.h

46c37
< # if __has_include ("__linux__/close_range.h")
---
> # if __has_include ("linux/close_range.h")

I would suggest removing the fixed includes in openSUSE as well?

Martin

> 
> On other targets I understand fixincludes is much more important.
> 
> 	Jakub
>