bug#20699: Acknowledgement (subdir-objects with source from sibling directory breaks distcheck)

[Peter Rosin]

On 2015-06-21 23:14, Hans-Bernhard Bröker wrote:
> It's actually even a little worse:
> 
> Any dependency on sources in another directory causes a simple "make clean" 
> in one directory to erase _all_ object files on that other one, i.e. if 
> docs/Makefile.am has
> 
> noinst_PROGRAMS = a
> 
> a_SOURCES = sub/a.c ../src/main.c
> a_CPPFLAGS = -DFOO=BAR $(AM_CPPFLAGS)
> 
> then "make -C docs clean" does the following:
> 
> make: Entering directory '/cygdrive/c/prg/gp/am_bug/amhello-1.0/docs'
> test -z "a.exe" || rm -f a.exe
> rm -f *.o
> rm -f ../src/*.o
> rm -f sub/*.o
> make: Leaving directory '/cygdrive/c/prg/gp/am_bug/amhello-1.0/docs'
> 
> But what logic would a "clean" in one sub project erase all the work done in 
> another?
> 
> With consequences like that, I think the (all but forced, now) option 
> "subdir-objects" needs to be reconsidered.

I think that in Automake it is implicit that a makefile controls the
directory of the makefile itself and possibly subdirectories of that
directory. Sibling directories of this main directory are supposed to be
controlled by a makefile in that sibling directory (or by a makefile in
a parent directory). Notice how the option is named *subdir*-objects
(and not *sibling*-objects or something such) and ../foo is hardly a
subdir.

You are perhaps better off converting the project to use a single
top level makefile instead of using a recursive build.

Cheers,
Peter