Gavin Smith wrote:
> > > The problem seems to have been that the config.h.in file was not updated
> > > when the gnulib module was imported.
> > >
> > > In tta/config.log, there were these lines:
> > >
> > > configure:31570: checking whether program_invocation_name is declared
> > > configure:31570: result: yes
> > > configure:31585: checking whether program_invocation_short_name is
> > > declared
> > > configure:31585: x86_64-linux-gnu-gcc -c -D_REENTRANT -D_GNU_SOURCE
> > > -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include
> > > -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 conftest.c >&5
> > > configure:31585: $? = 0
> > > configure:31585: result: yes
> > >
> > > tta/C/config.h did not have either definition in it.
> > >
> > > So I suspected that config.h.in was out of date (even though it had a
> > > time stamp
> > > from today).
> >
> > I've never seen such a behaviour (configure updated but config.h.in not
> > updated)
> > in the GNU Build System.
>
> Could it be because config.h.in is in a subdirectory? In tta/configure.ac
> there
> is:
>
> AC_CONFIG_HEADERS([C/config.h])
>
> I thought it was a bit strange for the code in tta/gnulib to be using
> tta/C/config.h as an include file (-I../../C appears on the compiler
> command line so it is found). The rules to rebuild "C/config.h" appear
> in tta/C/Makefile:
>
> $(srcdir)/config.h.in: $(am__configure_deps)
> $(AM_V_GEN)($(am__cd) $(top_srcdir) && $(AUTOHEADER))
> $(AM_V_at)rm -f stamp-h1
> $(AM_V_at)touch $@
>
> It seems that this may easily not run if make does not run in that
> subdirectory early enough.
Indeed, the explanation seems to be a combination of four factors:
1) You did not run "make distclean" before and "./configure" after
changing the set of Gnulib modules.
2) tta/configure.ac defines config.h to be in the C/ subdirectory.
3) The tta directory uses a "recursive" Makefile structure (i.e.
the subdirectory C/ has its own Makefile.am).
4) In tta/Makefile.am you define
SUBDIRS = gnulib/lib C . perl tests
Cf. [1]
So, the fix is to
- either adopt the habit of doing "make distclean" when changing the
configuration,
- or define
SUBDIRS = C gnulib/lib . perl tests
- or put config.h in a different directory and adjust SUBDIRS similarly,
- or use a non-recursive Makefile.am (i.e. tta/Makefile.am does
'include C/local.mk').
Bruno
[1] https://www.gnu.org/software/automake/manual/html_node/Subdirectories.html
