Re: _SHORTNAME in conditional

[Thomas Martitz]

Am 05.01.2016 um 22:05 schrieb Thomas Martitz:
> Hello,
>
> Given this fragment:
>
> bin_PROGRAMS = false true
> true_SOURCES = false.c
> true_CFLAGS = -DAM_TRUE
> true_SHORTNAME = t
> if FOO
> false_SOURCES = false.c
> false_CFLAGS = -DAM_FALSE
> false_SHORTNAME = f
> endif
>
> I receive a warning for false_SHORTNAME:
> Makefile.am:9: warning: automake does not support false_SHORTNAME 
> being defined conditionally
>
> What does that mean? Why is it unsupported? Other variables work just 
> fine.
>
> This is a problem for me, because I'm trying to construct the following:
>
> root/Makefile.am:
> if ENABLE_FOO
> include foo/Makefile.inc
> endif
>
> root/foo/Makefile.inc
> bin_PROGRAMS = foo
> foo_SOURCES = foo.c
> foo_SHORTNAME = foo
>
> As of now, there is no way to achieve that as the warning also appears 
> for foo_SHORTNAME. The workaround to move the conditional into 
> root/foo/Makefile.inc is ugly and breaks modularization of the project.
>
> Automake source code is a myth to me, I wasn't able to find the code 
> that implements this limitation (only the place where the warning is 
> printed (variable_value() => $self->check_defined_unconditionally in 
> Variable.pm)

To give some more context: the root issue I'm trying to resolve is that 
object filenames are constructed from the paths leading to it, even for 
subdir-objects.

I.e.
in a sub-Makefile.am
bin_PROGRAMS += %D%/foo
%C%_foo_SOURCES = foo.c

The object file will be called path_to_foo-foo.o. I do not want this, I 
want the file to be just called foo-foo.o. I ensure via subdir-objects 
that everything is unique.

Why do I want to avoid the standard object filename? I also construct a 
Makefile in the foo subdirectory. This is so that I can run make in the 
root directory and also in root/foo. In both make invocations, the same 
object file shall be created. This only works if the object filename 
does not include the path that leads to the object file.

This scheme works fine with %C%_foo_SHORTNAME unless I want to 
conditionally build the foo subdirectory in which case the warning.

I guess this means there is another viable solution to my root problem. 
Instead of having to use _SHORTNAME I could envision an automake option 
that surpresses the object filename construction like above and only 
uses the foo part of %C%_foo_SOURCES.

PS: Please don't suggest recursive automake, this is what I'm actually 
trying to get away from.

Best regards.