Generated files in Git

[Joel Sherrill]

On 05/16/2012 05:35 AM, Sebastian Huber wrote:
> Hello,
>
> we have found some files that are generated during build, and thus should not
> be under configuration management (CM).
When I saw the subject, I thought we would be discussing putting
autotools generated files in git. It would seem to address two
issues brought up in the "Build Issues" thread:

+ switching branches in git
+ need to bootstrap from clone
> If you put the RTEMS source tree under CM with for example Rational Synergy,
> then this leads to problems.

It just isn't a CM style issue. It is building from CD/DVD.

GCC had a recent discussion about trying to build from a read-only
tree. It was due to some autotools changes and their impact.
There wasn't a problem but they didn't want the autotools changes
to break this.


>
> So, when trying to build from a Rational Synergy work area, which by default is
> write protected, we get some errors. There are .c files, that are generated by
> running sed on a .in file, but that fails because the generated files were in
> the original Git repository, and thus migrated into Synergy. Actually only the
> Makefile.am and the .in should be under CM.
Are you putting autotools generated files in Synergy?

This is basically trying to build from a read-only source tree.  GCC
considers some files in the tree to "maintainer updated" and thus would
be OK to be in git and in the tree in this mode.
>
> As you know, there are two flavours of CM systems, CVS style (modify-commit)
> and RCS style (lock-modify-commit). Synergy is “RCS style”, while Git is CVS
> style. That is why we have bigger problems with this inconsistency.
>
> The “wrong” files are
>
>           - 3 .c files in rtems/testsuites/libtests/complex/
>
>           - 1 .c file in rtems/testsuites/libtests/math/
>
>           - 1 .c file in rtems/testsuites/libtests/mathf/
>
>           - 1 .c file in rtems/testsuites/libtests/mathl/
c/src/ada-tests/sptests/sp19 should be on your list.

What about the documentation? The version.texi file is generated
based on timestamp on the master file of the manual changes. Those
are in git also.

And autotools generated files if that should be up for discussion.
>
> Also, the Makefile does not clean the generated files on “make distclean”.
If we added autotools generated files, then we would have the same issue.
Plus distclean is not supposed to remove configure and Makefile.in.
>
> How to fix this?  Remove the generated files from Git and add a distclean hook?

Should the files be generated on the fly and placed in the build directory?

distclean is supposed to take you back to a "fresh tarball" state. If they
are not in git and generated into the build directory, then that would be
meet that requirement.

But I don't think that covers every case.

-- 
Joel Sherrill, Ph.D.             Director of Research&   Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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