Re: [doc] MAKEOVERRIDES is undocumented

[Alejandro Colomar]

Hi Jeffrey,

On 12/19/22 16:57, Jeffrey Walton wrote:
> On Mon, Dec 19, 2022 at 10:45 AM Alejandro Colomar
> <alx.manpages@gmail.com> wrote:
> > I needed to use MAKEOVERRIDES for updating a pkgconf (.pc) file.  I want it to
> > have the correct directory variables as used when building/installing the
> > library, so if the user specifies 'includedir=/foo/bar' in the command line, the
> > .pc file should be updated with that info.
> >
> > The rule I had to use is:
> >
> > $(_LIB_pc): $(_LIB_pc_u) Makefile | $$(@D)/
> >          $(info  SED             $@)
> >          sed 's/Version:.*/Version: $(DISTVERSION)/' <$< >$@
> >          sed -i 's,prefix=.*,prefix=$(prefix),' $@
> > ifneq ($(filter includedir=%,$(MAKEOVERRIDES)),)
> >          sed -i 's,includedir=.*,includedir=$(includedir),' $@
> > endif
> >
> > As you can see, I need to check if it was overridden in the command line
> > (otherwise, the default 'includedir=${prefix}/include' in the .pc file is fine).
> >    And then I do override it.
>
> I don't think you need to go to extremes. Just check if includedir is
> set. If so, use it. If not, use the default of $prefix/include.
>
> You can do this in your makefile [1,2]:
>
>     ifeq ($(includedir),)
>       includedir := $(prefix)/include
>       PC_INCLUDEDIR = $${prefix}/include
>     else
>       PC_INCLUDEDIR = $(includedir)
>     endif
>
>      myconfig.pc:
>          ...
>         @echo 'includedir=$(PC_INCLUDEDIR)' >> myconfig.pc
>
> Jeff
>
> [1] https://github.com/weidai11/cryptopp/blob/master/GNUmakefile#L202
> [2] https://github.com/weidai11/cryptopp/blob/master/GNUmakefile#L1544

Interesting!  Thanks for the idea!

Anyway, the missing documentation bug is still a concern :)


Cheers,

Alex

--
<http://www.alejandro-colomar.es/>

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