Re: Using @bindir@ etc. in C headers

[Peter Johansson]

Hi Florian,


On 5/6/20 8:57 pm, Florian Weimer wrote:
> I would like to define macros containing the standard paths, like this:
>
> #define BINDIR "@bindir@"
>
> It does not work due to this code in lib/autoconf/general.m4 (which
> appears to be predate DESTDIR support):
>
> # Installation directory options.
> # These are left unexpanded so users can "make install exec_prefix=/foo"
> # and all the variables that are supposed to be based on exec_prefix
> # by default will actually change.
> # Use braces instead of parens because sh, perl, etc. also accept them.
> # (The list follows the same order as the GNU Coding Standards.)
> AC_SUBST([bindir],         ['${exec_prefix}/bin'])dnl
> AC_SUBST([sbindir],        ['${exec_prefix}/sbin'])dnl
>
> Is there are generally approved way to work around this?  The manual
> tells us to use -D preprocessor arguments, but I'd prefer the
> explicitness of defining the macros via a header file.


I have the following in my Makefile.am, which I believe I borrowed from 
the manual of autoconf or automake. BUILT_SOURCES makes the header file 
be created before any compilation and CLEANFILES makes the header file 
be removed by 'make clean'.


CLEANFILES += configmake.h

BUILT_SOURCES += configmake.h

configmake.h: Makefile
    echo '#define BINDIR "$(bindir)"' >$@


Cheers,

Peter


> Thanks,
> Florian