About our autoconf problems

[Rainer Jung <ra...@kippdata.de>]

First thanks to Stefan for downgrading his release system. It is a good 
workaround for the observed problems.

Since downgrades are not a long term solution, here's the status info to 
avoid confusion.

We observed two problems that had to do with using a recent autoconf 
version (2.70 an above) during releasing:

- bundled APR configure broken (ongoing)

This is already fixed by adjusting one of our autoconf macros in APR 
1.7.x and trunk (I think not in 1.6.x). But we didn't have an APR 
release since a long time, so the deps tarball for httpd still contains 
the latest but unfixed APR version. Once we will have a new APR release 
und bundle that, this autoconf problem will be gone and the latest 
autoconf should again be fine.

- thread local detection broken in httpd.h (fixed)

This is not a configure time problem, but a compile time problem. But it 
is still related to configure, because since autoconf 2.70 our call to 
AC_PROG_CC also checks whether the compiler support C11. For some gcc 
versions, eg. 4.8.x, this leads in "-std=gnu11" being added to the 
compiler flags. This in combination with httpd.h in 2.4.53-rc1 lead to a 
compile time failure. That problem is now fixed by making httpd.h more 
robust, so fir that problem the downgrade is no longer needed.

Thanks and regards,

Rainer

Re: About our autoconf problems

[Ruediger Pluem <rp...@apache.org>]

On 3/10/22 9:09 AM, Rainer Jung wrote:
> First thanks to Stefan for downgrading his release system. It is a good workaround for the observed problems.
> 
> Since downgrades are not a long term solution, here's the status info to avoid confusion.
> 
> We observed two problems that had to do with using a recent autoconf version (2.70 an above) during releasing:
> 
> - bundled APR configure broken (ongoing)
> 
> This is already fixed by adjusting one of our autoconf macros in APR 1.7.x and trunk (I think not in 1.6.x). But we didn't have an
> APR release since a long time, so the deps tarball for httpd still contains the latest but unfixed APR version. Once we will have
> a new APR release und bundle that, this autoconf problem will be gone and the latest autoconf should again be fine.
> 
> - thread local detection broken in httpd.h (fixed)
> 
> This is not a configure time problem, but a compile time problem. But it is still related to configure, because since autoconf
> 2.70 our call to AC_PROG_CC also checks whether the compiler support C11. For some gcc versions, eg. 4.8.x, this leads in
> "-std=gnu11" being added to the compiler flags. This in combination with httpd.h in 2.4.53-rc1 lead to a compile time failure.

But isn't this a bug in autoconf to add this as 4.8.x does not implement C11? Or should we blame it on gcc 4.8.x to accept
-std=gnu11 if it doesn't implement this?
Irrespective of the answers to the the questions above it is good that we have the fix in httpd.h.

Regards

Rüdiger