Generate nt/gnulib.mk from lib/gnulib.mk

This was proposed by Paul Eggert <eggert@cs.ucla.edu>,
with the purpose of avoiding manual maintenance of
nt/gnulib.mk.

* nt/gnulib-modules-to-delete.cfg: New file.
* nt/Makefile.in (AM_V_GEN, am__v_GEN_, am__v_GEN_0)
(am__v_GEN_1): New variables.
(${srcdir}/gnulib.mk): Rules to generate gnulib.mk from
lib/gnulib.mk and list of modules in gnulib-modules-to-delete.cfg.

* make-dist (nt): Add gnulib-modules-to-delete.cfg to the list of
files to link.
* configure.ac (GNULIB_MK): Compute the value according to $opsys.
* autogen.sh: Create nt/gnulib.mk if it doesn't exist, before
running autoreconf.
* Makefile.in (gnulib_mk): New variable.
($(srcdir)/nt/gnulib.mk): Rule to produce it.
(AUTOMAKE_INPUTS): Use $(gnulib_mk) instead of a literal file
name.
* .gitignore: Add nt/gnulib.mk.

* src/w32.c (acl_errno_valid): Implement it here, as we no longer
build the acl-permissions module from Gnulib.

.gitignore

@@ -288,5 +288,6 @@ lib/SYS/
 /site-lisp/
 nt/emacs.rc
 nt/emacsclient.rc
+nt/gnulib.mk
 src/gdb.ini
 /var/

Makefile.in

@@ -98,6 +98,9 @@ configuration=@configuration@
 ### The nt/ subdirectory gets built only for MinGW
 NTDIR=@NTDIR@
 
+### $(srcdir)/nt/gnulib.mk for MinGW, else $(srcdir)/lib/gnulib.mk
+gnulib_mk=@GNULIB_MK@
+
 # 'make' verbosity.
 AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
 
@@ -451,10 +454,13 @@ $(srcdir)/aclocal.m4: $(ACLOCAL_INPUTS)
 	cd $(srcdir) && ACLOCAL_PATH='$(ACLOCAL_PATH)' $(ACLOCAL) -I m4
 
 AUTOMAKE_INPUTS = $(srcdir)/aclocal.m4 $(srcdir)/lib/Makefile.am \
-  $(srcdir)/lib/gnulib.mk
+  $(gnulib_mk)
 $(srcdir)/lib/Makefile.in: $(AUTOMAKE_INPUTS)
 	cd $(srcdir) && $(AUTOMAKE) --gnu -a -c lib/Makefile
 
+$(srcdir)/nt/gnulib.mk: $(srcdir)/lib/Makefile.in
+	$(MAKE) -C $(srcdir)/nt gnulib.mk
+
 # Regenerate files that this makefile would have made, if this makefile
 # had been built by Automake.  The name 'am--refresh' is for
 # compatibility with subsidiary Automake-generated makefiles.

autogen.sh

@@ -220,8 +220,13 @@ Please report any problems with this script to bug-gnu-emacs@gnu.org .'
   fi
 
   echo 'Your system has the required tools.'
-  echo "Running 'autoreconf -fi -I m4' ..."
 
+  ## Create nt/gnulib.mk if it doesn't exist, as autoreconf will need it.
+  if test ! -f nt/gnulib.mk; then
+      sed '/^[^#]/s|^.*$|/^## begin  *gnulib module &/,/^## end  *gnulib module &/c ## gnulib module & removed|' nt/gnulib-modules-to-delete.cfg | sed -f- lib/gnulib.mk > nt/gnulib.mk
+  fi
+
+  echo "Running 'autoreconf -fi -I m4' ..."
 
   ## Let autoreconf figure out what, if anything, needs doing.
   ## Use autoreconf's -f option in case autoreconf itself has changed.

configure.ac

@@ -774,6 +774,17 @@ fi
 dnl This is used in lib/Makefile.am to use nt/gnulib.mk, the
 dnl alternative to lib/gnulib.mk, so as to avoid generating header files
 dnl that clash with MinGW.
+case $opsys in
+  mingw32 )
+    GNULIB_MK='$(srcdir)/nt/gnulib.mk'
+    ;;
+  * )
+    GNULIB_MK='$(srcdir)/lib/gnulib.mk'
+    ;;
+
+esac
+AC_SUBST([GNULIB_MK])
+
 AM_CONDITIONAL([BUILDING_FOR_WINDOWSNT], [test "x$opsys" = "xmingw32"])
 
 # Avoid gnulib's tests for -lcrypto, so that there's no static dependency on it.

make-dist

@@ -482,7 +482,7 @@ echo "Making links to 'nt'"
 (cd nt
  ln emacs-x86.manifest emacs-x64.manifest ../${tempdir}/nt
  ln [a-z]*.bat [a-z]*.[ch] ../${tempdir}/nt
- ln *.in gnulib.mk ../${tempdir}/nt
+ ln *.in gnulib.mk gnulib-modules-to-delete.cfg ../${tempdir}/nt
  ln mingw-cfg.site epaths.nt INSTALL.W64 ../${tempdir}/nt
  ln ChangeLog.*[0-9] INSTALL README README.W32 ../${tempdir}/nt)
 

nt/Makefile.in

@@ -54,6 +54,11 @@ am__v_CCLD_ = $(am__v_CCLD_@AM_DEFAULT_V@)
 am__v_CCLD_0 = @echo "  CCLD    " $@;
 am__v_CCLD_1 =
 
+AM_V_GEN = $(am__v_GEN_@AM_V@)
+am__v_GEN_ = $(am__v_GEN_@AM_DEFAULT_V@)
+am__v_GEN_0 = @echo "  GEN     " $@;
+am__v_GEN_1 =
+
 AM_V_RC = $(am__v_RC_@AM_V@)
 am__v_RC_ = $(am__v_RC_@AM_DEFAULT_V@)
 am__v_RC_0 = @echo "  RC      " $@;
@@ -255,3 +260,8 @@ runemacs${EXEEXT}: ${srcdir}/runemacs.c $(EMACSRES)
 emacs.res ../src/emacs.res: emacs.rc ${srcdir}/icons/emacs.ico \
   ${srcdir}/icons/hand.cur ${srcdir}/$(EMACS_MANIFEST)
 	$(AM_V_RC)${WINDRES} -I ${srcdir} -O coff -o $@ $<
+
+${srcdir}/gnulib.mk: ${srcdir}/gnulib-modules-to-delete.cfg ${srcdir}/../lib/gnulib.mk
+	$(AM_V_GEN)sed '/^[^#]/s|^.*$$|/^## begin  *gnulib module &/,/^## end  *gnulib module &/c ## gnulib module & removed|' < $< | \
+	  sed -f- ${srcdir}/../lib/gnulib.mk > $@-t && \
+	  ${srcdir}/../build-aux/move-if-change $@-t $@

nt/gnulib-modules-to-delete.cfg

@@ -0,0 +1,66 @@
+# This is the list of modules to be deleted from ../lib/gnulib.mk.
+#
+# We delete them because they either conflict with MinGW headers or
+# headers in nt/inc, or because those modules won't compile with
+# MinGW, or because Emacs already has the corresponding facilities as
+# part of Emacs sources, and their implementation is incompatible with
+# Gnulib's.
+#
+# In general, do NOT remove anything from ../lib/gnulib.mk that
+# doesn't need to be removed, to minimize the differences from
+# upstream gnulib.mk and thus make the maintenance easier.  Every
+# header file whose generation is controlled by configure-time tests
+# does NOT need to be removed; instead, force the configure script to
+# accept whatever MinGW has to offer, by defining the appropriate
+# Autoconf variable in the nt/mingw-cfg.site file.  Headers that are
+# generated conditionally have the tell-tale "if GL_GENERATE_foo_H"
+# condition before their Makefile snippet in this file.  Likewise, do
+# NOT remove gnulib modules which introduce header files that don't
+# exist in MinGW and in nt/inc/, since they cannot possibly clash
+# with anything.  Gnulib modules that introduce source *.c files also
+# need not be removed; if they define functions that could clash with
+# the w32 substitutes in Emacs, disable their compilation by defining
+# suitable variables in nt/mingw-cfg.site.
+# ----------------------------------------------------------------------
+#
+# Copyright (C) 2017 Free Software Foundation, Inc.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This file is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this file.  If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception to the GNU General Public License,
+# this file may be distributed as part of a program that
+# contains a configuration script generated by Autoconf, under
+# the same distribution terms as the rest of that program.
+#
+acl-permissions
+allocator
+at-internal
+careadlinkat
+dirent
+dirfd
+fcntl
+fcntl-h
+inttypes-incomplete
+mkostemp
+pipe2
+secure_getenv
+signal-h
+stdio
+stdlib
+sys_select
+sys_stat
+sys_time
+sys_types
+tempname
+unistd