Re: subdir-objects & depcomp trouble

[Stepan Kasal]

Hello Patrick,

On Fri, Sep 30, 2005 at 09:48:25AM +0200, Patrick Guio wrote:
> libmylib_la_SOURCES = $(top_srcdir)/src/myfile.cc

this is the problem.

though it might seem counter-intiuitve, you should never specify srcdir
or top_srcdir in your Makefile.am.  You should use a relative path, ie.
in lib/Makefile.am you should use:

libmylib_la_SOURCES = ../src/myfile.cc

It's the job of the VPATH feature to find out that this is valid only
in the source tree, effectively transforming it to: lib/../src/myfile.cc

The reason is exactly what you discovered by your experience:
the directory prefix is used not only for finding the source, but also
for dependency tracking and with subdir-objects also for the directory
where the object will be created.

Does this work for you?

(Well, I should admit that I'm mostly guessing.  But if it helps you,
you could perhaps forgive me.  ;-)

Stepan Kasal


A footnote:

Because top_builddir is always a relative path, it should be safe to use:

libmylib_la_SOURCES = $(top_builddir)/src/myfile.cc

but it really looks confusing, so I don't recommend it, unless necessary.
(If is necessary if the same makefile fragment is included by Makefile.am's
in different depths.)