# Including git-describe info as version strings for generic "-v" output 4 messages from 2012-01-21 to 2012-01-23. Participants: Harry portobello, Junio C Hamano, Dirk Süsserott, demerphq. Thread: https://gitlist.dev/t/29419 ## Harry portobello, 2012-01-21 19:09 Subject: Including git-describe info as version strings for generic "-v" output Message-ID: URL: https://gitlist.dev/e/CAG_NL2So7cf6o%2Ben9ktHGr94Eu5WJ9giWq6OmSxK%2BZL4RdtaGA%40mail.gmail.com ``` Hi all, I hope the subject makes sense -- I'll explain what I'm trying to do. I'm wondering what the best approaches are to being able to include output from git-describe [1] for generic version strings in projects managed by Git? This would have to work from within an autotools-managed project. At the moment, I've managed to hook the output from git-describe in to a few .m4 files, which works only at ./configure time -- but of course, with this being Git, I'd ideally like the same mechanism to work in a situation where someone does: $ git pull && make It's knowing how to plumb this in to the Makefile.am part I'm hazy over. Any help would be much appreciated. Harry [1] I know it's "git describe"; I'm using its hyphenated form for clarity of context. ``` ## Junio C Hamano, 2012-01-21 22:03 Subject: Re: Including git-describe info as version strings for generic "-v" output Message-ID: <7vd3acbtn3.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vd3acbtn3.fsf%40alter.siamese.dyndns.org In-Reply-To: ``` Harry portobello writes: > I hope the subject makes sense -- I'll explain what I'm trying to do. Perhaps take a look at GIT-VERSION-GEN that is part of the Git source? ``` ## Dirk Süsserott, 2012-01-22 16:03 Subject: Re: Including git-describe info as version strings for generic "-v" output Message-ID: <4F1C335D.7020802@dirk.my1.cc> URL: https://gitlist.dev/e/4F1C335D.7020802%40dirk.my1.cc In-Reply-To: <7vd3acbtn3.fsf@alter.siamese.dyndns.org> ``` Am 21.01.2012 23:03 schrieb Junio C Hamano: > Harry portobello writes: > >> I hope the subject makes sense -- I'll explain what I'm trying to do. > > Perhaps take a look at GIT-VERSION-GEN that is part of the Git source? At work, we have the same "problem". I solved it like so: version.h: ---------------------------------------------- #ifndef __version_h__ #define __version_h__ #ifdef __cplusplus extern "C" { #endif /* * Returns a version string as defined with the -D compiler switch. */ char const * software_version(); #ifdef __cplusplus } #endif #endif ---------------------------------------------- version.c: ---------------------------------------------- #include "version.h" char const * software_version() { return SW_VERSION; } ---------------------------------------------- And then make sure that ONLY version.c gets compiled like this: gcc -DSW_VERSION=\"$(git describe --dirty)\" \ [other options] \ -c version.c -o version.o Actually I use Scons to build my software (not Make). Scons automatically keeps track of dependencies and changed compiler switches between its runs. Thus it will re-compile version.c if the output of git-describe changes. That's why Scons users must make sure that the -D-switch is given only to version.c (else Scons would re-compile ALL files because of the different argument to -D). If you are using Make then make sure that version.c gets compiled always. The drawback is that your app will be re-linked with every single Make run. That's why I prefer Scons: it calculates the dependencies on a checksum basis. If the *contents* of version.c together with the compiler options didn't change, it won't re-compile it. Furtermore: if the *contents* of version.o didn't change, it won't re-link. Timestamps don't matter to Scons. But that's another topic :-) HTH Dirk ``` ## demerphq, 2012-01-23 11:16 Subject: Re: Including git-describe info as version strings for generic "-v" output Message-ID: URL: https://gitlist.dev/e/CANgJU%2BXUg8%3DWMjHLNhe9kxgoGna6m4%2BYyduBRNGurAke12vLgg%40mail.gmail.com In-Reply-To: ``` On 21 January 2012 20:09, Harry portobello wrote: > Hi all, > > I hope the subject makes sense -- I'll explain what I'm trying to do. > > I'm wondering what the best approaches are to being able to include > output from git-describe [1] for generic version strings in projects > managed by Git? This would have to work from within an > autotools-managed project. > > At the moment, I've managed to hook the output from git-describe in to > a few .m4 files, which works only at ./configure time -- but of > course, with this being Git, I'd ideally like the same mechanism to > work in a situation where someone does: > > $ git pull && make > > It's knowing how to plumb this in to the Makefile.am part I'm hazy over. > > Any help would be much appreciated. FWIW Perl does something like this. Have a look at the Perl makefiles for an example. Yves -- perl -Mre=debug -e "/just|another|perl|hacker/" ```