Resolving conflicts between gnulib and nt/inc headers

Resolving conflicts between gnulib and nt/inc headers

[Eli Zaretskii]

In my work on building the w32 Emacs by running the Posix configury, I
hit a problem with headers produced in lib/ which conflict with the
headers we have in nt/inc/ and with the MinGW system headers.

In the current Windows build scripts, most of the lib/*.in.h templates
are not edited into the corresponding *.h files, so these problems
never arise.  But when using the Posix build procedure, lib/Makefile
is produced such that most of these headers are generated
unconditionally (so I cannot control that from the configure script).
Here's a partial list of those headers:

  inttypes.h
  sys/stat.h
  time.h
  signal.h
  stdio.h

For now, I'm forced to use a very dirty trick: define some macro that
forces gnulib headers to just #include_next the same header either
from nt/inc or from the syste, include directory.  E.g., to bypass
gnulib's time.h, I define _GL_TIME_H (yuck!).  But I certainly hope
there is a cleaner way, or perhaps gnulib maintainers could add a
cleaner way if there isn't one already.  E.g., how can I prevent
certain headers from being produced from their *.in.h templates?

Any suggestions are welcome.  TIA.

P.S.  Progress report: (1) the configure script runs and produces a
correct src/config.h; (2) the programs in lib-src compile and link OK;
(3) C sources in src/ compile with a few warnings and one error.

Re: Resolving conflicts between gnulib and nt/inc headers

[Paul Eggert]

On 03/30/13 10:29, Eli Zaretskii wrote:
> how can I prevent
> certain headers from being produced from their *.in.h templates?

One possibility would be to edit lib/Makefile.am
to replace this line:

 include gnulib.mk

with something like this:

 if WINDOWSNT
 include ../nt/gnulib.mk
 else
 include gnulib.mk
 endif

and to add something like this to configure.ac:

 AM_CONDITIONAL([WINDOWSNT], [test that we're running under MS-Windows])

You can then put into the MS-Windows gnulib.mk
whatever you like.

Ideally the Emacs and Gnulib substitutes should be
merged, of course, but that's a bigger project.

Re: Resolving conflicts between gnulib and nt/inc headers

[Eli Zaretskii]

> Date: Sat, 30 Mar 2013 12:00:11 -0700
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: emacs-devel@gnu.org
> 
> One possibility would be to edit lib/Makefile.am
> to replace this line:
> 
>  include gnulib.mk
> 
> with something like this:
> 
>  if WINDOWSNT
>  include ../nt/gnulib.mk
>  else
>  include gnulib.mk
>  endif

Thanks, this is indeed much cleaner.  I will see to making this
happen.

> Ideally the Emacs and Gnulib substitutes should be
> merged, of course, but that's a bigger project.

Indeed.  I actually considered that as an alternative, but the current
substitutes in Emacs are not easily extracted to separate files, and
some of them depend on non-trivial infrastructure that might not even
be appropriate for a general-purpose library.