Make gnulib a git submodule.

* .gitmodules: New file.
* gnulib: Record which version of gnulib has been tested.
* bootstrap: Aid in submodule usage.
* cfg.mk (gnulib_dir): Alter default location of gnulib.
* HACKING: Mention how to use submodule.

Signed-off-by: Eric Blake <ebb9@byu.net>
(cherry picked from commit 6942f58cb5bb624a28672658a4369b85bce77783)

6 files changed, 98 insertions, 54 deletions

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..acb26693
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "gnulib"]
+	path = gnulib
+	url = git://git.sv.gnu.org/gnulib.git
diff --git a/ChangeLog b/ChangeLog
index f25fbe92..4c9c95a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-03-23  Eric Blake  <ebb9@byu.net>
+
+	Make gnulib a git submodule.
+	* .gitmodules: New file.
+	* gnulib: Record which version of gnulib has been tested.
+	* bootstrap: Aid in submodule usage.
+	* cfg.mk (gnulib_dir): Alter default location of gnulib.
+	* HACKING: Mention how to use submodule.
+
 2009-03-21  Eric Blake  <ebb9@byu.net>
 
 	Use memcmp2 to simplify lexicographic comparisons.
diff --git a/HACKING b/HACKING
index 17bbeafe..b4099006 100644
--- a/HACKING
+++ b/HACKING
@@ -73,19 +73,46 @@ and is not part of a release distribution.
   - LZMA Utils 4.32 or later (from <http://tukaani.org/lzma/>)
   - Texinfo 4.8 or later
   - Any prerequisites of the above (such as perl, tex)
-  - A git checkout of gnulib.  A read-only copy of gnulib can be
-    obtained by:
+
+  Note that none of these bootstrapping dependencies should be required
+  by a distributed release.
+
+* M4 includes gnulib as a git submodule.  By default, the bootstrap
+  script will attempt to run
+    git submodule update --init
+  to grab a gnulib clone from the official read-only location of
+    git://git.sv.gnu.org/gnulib.git
+
+  However, this can be network and disk intensive.  If you already have
+  another gnulib clone on your disk, you can use the environment
+  variable GNULIB_SRCDIR to point to the previous checkout to speed up
+  the process.  Additionally, both the bootstrap script and gnulib-tool
+  require a shell that supports functions, so you can set the
+  environment variable  CONFIG_SHELL to choose a better shell on systems
+  (like Solaris) where /bin/sh is lacking.  Thus, you may find it
+  convenient to run:
+    GNULIB_SRCDIR=path/to/gnulib CONFIG_SHELL=path/to/sh \
+      path/to/sh ./bootstrap
+
+  A read-only copy of gnulib can be obtained by:
       git clone git://git.sv.gnu.org/gnulib.git
     or
       cvs -d:pserver:anonymous@pserver.git.sv.gnu.org:/srv/git/gnulib.git \
         co -d gnulib HEAD
 
+  Using a CVS checkout might work, but it is relatively untested,
+  particularly now that we use a git submodule for gnulib.
+
   If you are a member of the savannah group for gnulib, a read-write
   copy can be obtained by:
     git clone <savannah-user>@git.sv.gnu.org:/srv/git/gnulib.git
 
-  Note that none of these bootstrapping dependencies should be required
-  by a distributed release.
+  If you are behind a firewall that blocks the git protocol, you may
+  find it useful to do:
+    git config --global url.http://git.sv.gnu.org/r/.insteadof \
+      git://git.sv.gnu.org/
+  to force git to transparently rewrite all savannah git references to
+  instead use http.
 
 * Either add the gnulib directory to your PATH, or run
     GNULIB_TOOL=path/to/gnulib/gnulib-tool ./bootstrap
@@ -214,13 +241,18 @@ yyyy-mm-dd  Name of Author  <email@address>  (tiny change)
 
 * Make sure your locale is sane, e.g. by exporting LC_ALL=C.
 
+* Make sure you are happy with the particular gnulib version recorded as
+  the gnulib submodule.  If necessary to update to the latest, run:
+    git submodule foreach git pull
+    git commit -m 'Update gnulib submodule to latest.' gnulib
+
 * Update the version number in configure.ac.
   See http://www.gnu.org/software/libtool/contribute.html for details of
   the numbering scheme (m4 uses the same scheme as libtool).
 
 * Update NEWS, ChangeLog.
 
-* Run ./bootstrap.
+* Run ./bootstrap, perhaps with environment variables set.
 
 * Run ./configure (or create a build directory first and run configure
   from there, if you want to keep the build tree separate).
diff --git a/bootstrap b/bootstrap
index 8bc30213..f5d7321d 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# bootstrap (GNU M4) version 2009-03-13
+# bootstrap (GNU M4) version 2009-03-23
 # Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Free Software
 # Foundation, Inc.
 # License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
@@ -33,7 +33,7 @@
 
 # You can also set the following variables to help $progname
 # locate the right tools:
-#   AUTOPOINT, AUTORECONF, AWK, GNULIB_SRCDIR, GNULIB_TOOL, LIBTOOLIZE,
+#   AUTOPOINT, AUTORECONF, AWK, CONFIG_SHELL, GNULIB_SRCDIR, LIBTOOLIZE,
 #   M4, RM, SED
 
 # This script bootstraps a git or CVS checkout of GNU M4 by correctly calling
@@ -50,7 +50,7 @@
 : ${AUTOPOINT=autopoint}
 : ${AUTORECONF=autoreconf}
 : ${AWK=awk}
-: ${GNULIB_TOOL=gnulib-tool}
+: ${CONFIG_SHELL=/bin/sh}
 : ${LIBTOOLIZE=libtoolize}
 : ${M4=m4}
 : ${RM='rm -f'}
@@ -396,35 +396,33 @@ $AUTOPOINT --force
 func_echo "running: $LIBTOOLIZE --force --copy --install"
 ${LIBTOOLIZE} --force --copy --install
 
-## ---------------------------- ##
-## Find the gnulib module tree. ##
-## ---------------------------- ##
+## ------------------------------ ##
+## Update the gnulib module tree. ##
+## ------------------------------ ##
 
-if test -n "$GNULIB_SRCDIR" && test -d "$GNULIB_SRCDIR" ; then
-  gnulibdir=$GNULIB_SRCDIR
+if test -d .git && (git --version) >/dev/null 2>/dev/null ; then
+  if test -f gnulib/gnulib-tool ; then
+    func_echo "updating gnulib submodule"
+    git submodule update \
+      || func_fatal_error "Unable to update gnulib"
+  else
+    # A fresh checkout creates an empty subdirectory gnulib.  However,
+    # older git didn't know how to clone into an empty subdir.  If the
+    # user provided GNULIB_SRCDIR, then make the initial clone refer
+    # to the existing checkout, to save network traffic.
+    func_echo "importing gnulib submodule"
+    if test -d "$GNULIB_SRCDIR" ; then
+      rmdir gnulib 2>/dev/null
+      git clone --reference "$GNULIB_SRCDIR" git://git.sv.gnu.org/gnulib.git \
+ && git submodule init && git submodule update \
+ || func_fatal_error "Unable to update gnulib"
+    else
+      git submodule update --init \
+ || func_fatal_error "Unable to update gnulib"
+    fi
+  fi
 else
-  case $GNULIB_TOOL in
-    /*  )  gnulibdir=$GNULIB_TOOL ;;		# absolute
-    */* )  gnulibdir=`pwd`/$GNULIB_TOOL ;;	# relative
-    *   )  gnulibdir=`which "$GNULIB_TOOL"` ;;	# PATH search
-  esac
-
-  # Follow symlinks
-  while test -h "$gnulibdir"; do
-
-    # Resolve symbolic link.
-    sedexpr1='s, -> ,#%%#,'
-    sedexpr2='s,^.*#%%#\(.*\)$,\1,p'
-    linkval=`ls -l "$gnulibdir" | $SED "$sedexpr1" | $SED -n "$sedexpr2"`
-    test -n "$linkval" || break
-
-    case "$linkval" in
-	/* ) gnulibdir="$linkval" ;;
-	* )  gnulibdir=`echo "$gnulibdir" | sed -e 's,/[^/]*$,,'`/"$linkval" ;;
-    esac
-
-  done
-  gnulibdir=`echo "$gnulibdir" | $SED "$dirname"`
+  func_echo "git not detected.  If needed, update gnulib subdirectory manually"
 fi
 
 
@@ -432,9 +430,9 @@ fi
 ## Import Gnulib modules. ##
 ## ---------------------- ##
 
-func_echo "running: ${GNULIB_TOOL} --update"
-${GNULIB_TOOL} --update
-
+func_echo "running: $CONFIG_SHELL gnulib/gnulib-tool --update"
+$CONFIG_SHELL gnulib/gnulib-tool --update \
+  || func_fatal_error "gnulib-tool failed"
 
 ## --------------------------------- ##
 ## Copy additional src only modules. ##
@@ -442,7 +440,8 @@ ${GNULIB_TOOL} --update
 
 func_echo "fetching modules for src directory"
 
-for file in `${GNULIB_TOOL} --extract-filelist $src_modules`; do
+for file in `$CONFIG_SHELL gnulib/gnulib-tool --extract-filelist $src_modules`
+do
 
     dest=`echo $file | $SED "$basename"`
     case $file in
@@ -454,11 +453,11 @@ for file in `${GNULIB_TOOL} --extract-filelist $src_modules`; do
     esac
 
     # Be sure to show all copying errors before bailing out
-    if test -f $gnulibdir/$file; then
+    if test -f gnulib/$file; then
 	func_echo "copying file \`$dest'"
-	cp $gnulibdir/$file $dest
+	cp gnulib/$file $dest
     else
-	func_error "$gnulibdir/$file does not exist"
+	func_error "gnulib/$file does not exist"
 	bailout_cb="exit 1"
     fi
 done
@@ -480,17 +479,18 @@ AUTOPOINT=true LIBTOOLIZE=true \
 ## Gnulib is more up-to-date than automake. ##
 ## ---------------------------------------- ##
 
-func_update "$gnulibdir"/build-aux/config.guess $config_aux_dir/config.guess
-func_update "$gnulibdir"/build-aux/config.sub $config_aux_dir/config.sub
-func_update "$gnulibdir"/build-aux/depcomp $config_aux_dir/depcomp
-func_update "$gnulibdir"/build-aux/install-sh $config_aux_dir/install-sh
-func_update "$gnulibdir"/build-aux/mdate-sh $config_aux_dir/mdate-sh
-func_update "$gnulibdir"/build-aux/missing $config_aux_dir/missing
-func_update "$gnulibdir"/build-aux/texinfo.tex $config_aux_dir/texinfo.tex
-func_update "$gnulibdir"/build-aux/po/Makefile.in.in po/Makefile.in.in
-func_update "$gnulibdir"/build-aux/po/remove-potcdate.sin po/remove-potcdate.sin
-func_update "$gnulibdir"/doc/COPYINGv3 COPYING
-func_update "$gnulibdir"/doc/INSTALL INSTALL
+func_update gnulib/build-aux/compile $config_aux_dir/compile
+func_update gnulib/build-aux/config.guess $config_aux_dir/config.guess
+func_update gnulib/build-aux/config.sub $config_aux_dir/config.sub
+func_update gnulib/build-aux/depcomp $config_aux_dir/depcomp
+func_update gnulib/build-aux/install-sh $config_aux_dir/install-sh
+func_update gnulib/build-aux/mdate-sh $config_aux_dir/mdate-sh
+func_update gnulib/build-aux/missing $config_aux_dir/missing
+func_update gnulib/build-aux/texinfo.tex $config_aux_dir/texinfo.tex
+func_update gnulib/build-aux/po/Makefile.in.in po/Makefile.in.in
+func_update gnulib/build-aux/po/remove-potcdate.sin po/remove-potcdate.sin
+func_update gnulib/doc/COPYINGv3 COPYING
+func_update gnulib/doc/INSTALL INSTALL
 
 
 ## ------- ##
diff --git a/cfg.mk b/cfg.mk
index a67d0883..2aac5ac6 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -37,4 +37,4 @@ local-checks-to-skip = changelog-check
 
 # The local directory containing the checked-out copy of gnulib used in this
 # release.  Used solely to get gnulib's SHA1 for the "announcement" target.
-gnulib_dir = $(srcdir)/../gnulib
+gnulib_dir = $(srcdir)/gnulib
diff --git a/gnulib b/gnulib
new file mode 160000
+Subproject 6c410f6d2875a0a41671daab4d9751a74c69c45