Re: Conventions on build variables

[Bob Friesenhahn]

On Mon, 26 Aug 2019, Sébastien Hinderer wrote:
> > > For instance, regarding variables such as CC or CFLAGS, when they are
> > > passed to configure, should they be recorded somewhere so that a future
> > > invocation of make takes them into account?
> >
> > Yes, they should normally be recorded in the Makefile so that they are used
> > in the build.
>
> Okay. Still, I guess if make is invoked with a different value of CC it
> is then expected that this new value takes precedence over then one
> stored in the Makefile, right?

I would expect that to be true, but I would also expect that the new 
CC or CFLAGS might not be compatible with what configure figured out 
using the original settings.

> Similarly, I kind of remember that if, say, make install is invoked with
> a different value of PREFIX that value must be taken into acocunt and
> that it is required that PREFIX can have different values during make
> and make isntall. I am wondering whether there is a document which
> specifies clearly for which variable this is expected to work that way
> and couldn't find anything relevant on the web site of the FSF.

You are likely thinking of 'DESTDIR', which is different than prefix. 
DESTDIR comes from the build environment and not from the Makefile or 
configure script.

> > Otherwise you need to make sure that the necessary
> > artifacts are in Makefile.in.
>
> I don't mind taking care of this, I am just unsure at the moment about
> what exactly is expected.

If you are preparing your own Makefile, then following the GNU coding 
standards as well as the standard definitions documented in the GNU 
make manual will help quite a lot.  The standard INSTALL text file 
documents many of these conventions.

You will find available substitutions stored in the generated 
config.status script.

Bob
--
Bob Friesenhahn
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