Patchwork [pushed] Import the strerror_r-posix module and use it in GDB.

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Submitter Simon Marchi (Code Review)
Date Nov. 15, 2019, 7:14 p.m.
Message ID <20191115191408.B219E28171@gnutoolchain-gerrit.osci.io>
Download mbox | patch
Permalink /patch/35953/
State New
Headers show

Comments

Simon Marchi (Code Review) - Nov. 15, 2019, 7:14 p.m.
Sourceware to Gerrit sync has submitted this change.

Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/514
......................................................................

Import the strerror_r-posix module and use it in GDB.

Makes sure to assign the return value of strerror_r to an int,
so that we get a compile error if we accidentally get the
wrong version.

gdb/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* config.in: Regenerate.
	* configure: Regenerate.
	* gdbsupport/common.m4: No longer check for strerror_r.
	* gdbsupport/posix-strerror.c (safe_strerror): Always call the
	POSIX version of strerror_r, now that gnulib provides it if
	necessary.

gdb/gdbserver/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* config.in: Regenerate.
	* configure: Regenerate.

gnulib/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* config.in: Regenerate.
	* configure: Regenerate.
	* import/Makefile.am: Update.
	* import/Makefile.in: Regenerate.
	* import/extra/config.rpath: New file.
	* import/glthread/lock.c: New file.
	* import/glthread/lock.h: New file.
	* import/glthread/threadlib.c: New file.
	* import/m4/gnulib-cache.m4: Update.
	* import/m4/gnulib-comp.m4: Update.
	* import/m4/lib-ld.m4: New file.
	* import/m4/lib-link.m4: New file.
	* import/m4/lib-prefix.m4: New file.
	* import/m4/lock.m4: New file.
	* import/m4/strerror_r.m4: New file.
	* import/m4/threadlib.m4: New file.
	* import/strerror_r.c: New file.
	* update-gnulib.sh: Import strerror_r-posix.

Change-Id: I5cfeb12a5203a4cd94a78581541e6085a68685c3
---
M gdb/ChangeLog
M gdb/config.in
M gdb/configure
M gdb/gdbserver/ChangeLog
M gdb/gdbserver/config.in
M gdb/gdbserver/configure
M gdb/gdbsupport/common.m4
M gdb/gdbsupport/posix-strerror.c
M gnulib/ChangeLog
M gnulib/Makefile.in
M gnulib/aclocal.m4
M gnulib/config.in
M gnulib/configure
M gnulib/import/Makefile.am
M gnulib/import/Makefile.in
A gnulib/import/extra/config.rpath
A gnulib/import/glthread/lock.c
A gnulib/import/glthread/lock.h
A gnulib/import/glthread/threadlib.c
M gnulib/import/m4/gnulib-cache.m4
M gnulib/import/m4/gnulib-comp.m4
A gnulib/import/m4/lib-ld.m4
A gnulib/import/m4/lib-link.m4
A gnulib/import/m4/lib-prefix.m4
A gnulib/import/m4/lock.m4
A gnulib/import/m4/strerror_r.m4
A gnulib/import/m4/threadlib.m4
A gnulib/import/strerror_r.c
M gnulib/update-gnulib.sh
29 files changed, 6,662 insertions(+), 162 deletions(-)

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 134c883..0f92504 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@ 
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
+	* config.in: Regenerate.
+	* configure: Regenerate.
+	* gdbsupport/common.m4: No longer check for strerror_r.
+	* gdbsupport/posix-strerror.c (safe_strerror): Always call the
+	POSIX version of strerror_r, now that gnulib provides it if
+	necessary.
+
 2019-11-14  Christian Biesinger  <cbiesinger@google.com>
 
 	* README (`configure' options): Update.
diff --git a/gdb/config.in b/gdb/config.in
index 5a21fca..fc05f15 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -423,9 +423,6 @@ 
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Define to 1 if you have the `strerror_r' function. */
-#undef HAVE_STRERROR_R
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
diff --git a/gdb/configure b/gdb/configure
index 512f016..e805903 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -13480,7 +13480,7 @@ 
 
 
   for ac_func in fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r
+		  sigprocmask
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index e17a7ca..0f0fc03 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@ 
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
+	* config.in: Regenerate.
+	* configure: Regenerate.
+
 2019-11-12  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* ax.c (ax_printf): Handle size_t_arg.
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 2984281..0bce18d 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -229,9 +229,6 @@ 
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Define to 1 if you have the `strerror_r' function. */
-#undef HAVE_STRERROR_R
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 3f1f1c1..e513fc5 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -6822,7 +6822,7 @@ 
 
 
   for ac_func in fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r
+		  sigprocmask
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/gdb/gdbsupport/common.m4 b/gdb/gdbsupport/common.m4
index 2e44cf4..471d705 100644
--- a/gdb/gdbsupport/common.m4
+++ b/gdb/gdbsupport/common.m4
@@ -33,7 +33,7 @@ 
 		   dlfcn.h)
 
   AC_CHECK_FUNCS([fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r])
+		  sigprocmask])
 
   AC_CHECK_DECLS([strerror, strstr])
 
diff --git a/gdb/gdbsupport/posix-strerror.c b/gdb/gdbsupport/posix-strerror.c
index 34420cf..107813f 100644
--- a/gdb/gdbsupport/posix-strerror.c
+++ b/gdb/gdbsupport/posix-strerror.c
@@ -18,6 +18,7 @@ 
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "common-defs.h"
+#include <string.h>
 
 /* Implementation of safe_strerror as defined in common-utils.h.  */
 
@@ -26,23 +27,12 @@ 
 {
   static thread_local char buf[1024];
 
-  char *msg = nullptr;
-#ifdef HAVE_STRERROR_R
-#  if !__GLIBC__ || ((_POSIX_C_SOURCE >= 200112L) && !  _GNU_SOURCE)
-  /* Glibc has two different, incompatible versions of strerror_r.  */
-  if (strerror_r (errnum, buf, sizeof (buf)) == 0)
-    msg = buf;
-#  else
-  msg = strerror_r (errnum, buf, sizeof (buf));
-#  endif
-#else
-  msg = strerror (errnum);
-#endif
-  if (msg == nullptr)
-    {
+  /* Assign the return value to an int, so we get an error if we accidentally
+     get the wrong version of this function (glibc has two of them...).  */
+  int ret = strerror_r (errnum, buf, sizeof (buf));
+  if (ret == 0)
+    return buf;
 
-      xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
-      msg = buf;
-    }
-  return (msg);
+  xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
+  return buf;
 }
diff --git a/gnulib/ChangeLog b/gnulib/ChangeLog
index 89c0c17..b1acb4c 100644
--- a/gnulib/ChangeLog
+++ b/gnulib/ChangeLog
@@ -1,5 +1,28 @@ 
 2019-11-15  Christian Biesinger  <cbiesinger@google.com>
 
+	* Makefile.in: Regenerate.
+	* aclocal.m4: Regenerate.
+	* config.in: Regenerate.
+	* configure: Regenerate.
+	* import/Makefile.am: Update.
+	* import/Makefile.in: Regenerate.
+	* import/extra/config.rpath: New file.
+	* import/glthread/lock.c: New file.
+	* import/glthread/lock.h: New file.
+	* import/glthread/threadlib.c: New file.
+	* import/m4/gnulib-cache.m4: Update.
+	* import/m4/gnulib-comp.m4: Update.
+	* import/m4/lib-ld.m4: New file.
+	* import/m4/lib-link.m4: New file.
+	* import/m4/lib-prefix.m4: New file.
+	* import/m4/lock.m4: New file.
+	* import/m4/strerror_r.m4: New file.
+	* import/m4/threadlib.m4: New file.
+	* import/strerror_r.c: New file.
+	* update-gnulib.sh: Import strerror_r-posix.
+
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
 	* Makefile.am: New file.
 	* Makefile.in: Replace with generated file.
 	* aclocal-m4-deps.mk: Remove.
diff --git a/gnulib/Makefile.in b/gnulib/Makefile.in
index d68e434..0379972 100644
--- a/gnulib/Makefile.in
+++ b/gnulib/Makefile.in
@@ -169,11 +169,15 @@ 
 	$(top_srcdir)/import/m4/isnand.m4 \
 	$(top_srcdir)/import/m4/isnanl.m4 \
 	$(top_srcdir)/import/m4/largefile.m4 \
+	$(top_srcdir)/import/m4/lib-ld.m4 \
+	$(top_srcdir)/import/m4/lib-link.m4 \
+	$(top_srcdir)/import/m4/lib-prefix.m4 \
 	$(top_srcdir)/import/m4/limits-h.m4 \
 	$(top_srcdir)/import/m4/localcharset.m4 \
 	$(top_srcdir)/import/m4/locale-fr.m4 \
 	$(top_srcdir)/import/m4/locale-ja.m4 \
 	$(top_srcdir)/import/m4/locale-zh.m4 \
+	$(top_srcdir)/import/m4/lock.m4 \
 	$(top_srcdir)/import/m4/longlong.m4 \
 	$(top_srcdir)/import/m4/lstat.m4 \
 	$(top_srcdir)/import/m4/malloc.m4 \
@@ -227,6 +231,7 @@ 
 	$(top_srcdir)/import/m4/strchrnul.m4 \
 	$(top_srcdir)/import/m4/strdup.m4 \
 	$(top_srcdir)/import/m4/strerror.m4 \
+	$(top_srcdir)/import/m4/strerror_r.m4 \
 	$(top_srcdir)/import/m4/string_h.m4 \
 	$(top_srcdir)/import/m4/strstr.m4 \
 	$(top_srcdir)/import/m4/strtok_r.m4 \
@@ -236,6 +241,7 @@ 
 	$(top_srcdir)/import/m4/sys_types_h.m4 \
 	$(top_srcdir)/import/m4/sys_uio_h.m4 \
 	$(top_srcdir)/import/m4/tempname.m4 \
+	$(top_srcdir)/import/m4/threadlib.m4 \
 	$(top_srcdir)/import/m4/time_h.m4 \
 	$(top_srcdir)/import/m4/unistd-safer.m4 \
 	$(top_srcdir)/import/m4/unistd_h.m4 \
@@ -313,13 +319,13 @@ 
 DIST_SUBDIRS = $(SUBDIRS)
 am__DIST_COMMON = $(srcdir)/Makefile.in $(srcdir)/config.in \
 	$(top_srcdir)/../ar-lib $(top_srcdir)/../compile \
-	$(top_srcdir)/../config.guess $(top_srcdir)/../config.sub \
-	$(top_srcdir)/../install-sh $(top_srcdir)/../missing \
-	$(top_srcdir)/../mkinstalldirs ../COPYING ../COPYING.LIB \
-	../ChangeLog ../README ../ar-lib ../compile ../config.guess \
-	../config.rpath ../config.sub ../depcomp ../install-sh \
-	../ltmain.sh ../missing ../mkinstalldirs ../ylwrap ChangeLog \
-	README
+	$(top_srcdir)/../config.guess $(top_srcdir)/../config.rpath \
+	$(top_srcdir)/../config.sub $(top_srcdir)/../install-sh \
+	$(top_srcdir)/../missing $(top_srcdir)/../mkinstalldirs \
+	../COPYING ../COPYING.LIB ../ChangeLog ../README ../ar-lib \
+	../compile ../config.guess ../config.rpath ../config.sub \
+	../depcomp ../install-sh ../ltmain.sh ../missing \
+	../mkinstalldirs ../ylwrap ChangeLog README
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
@@ -1115,8 +1121,12 @@ 
 LIBGNU_LIBDEPS = @LIBGNU_LIBDEPS@
 LIBGNU_LTLIBDEPS = @LIBGNU_LTLIBDEPS@
 LIBINTL = @LIBINTL@
+LIBMULTITHREAD = @LIBMULTITHREAD@
 LIBOBJS = @LIBOBJS@
+LIBPTH = @LIBPTH@
+LIBPTH_PREFIX = @LIBPTH_PREFIX@
 LIBS = @LIBS@
+LIBTHREAD = @LIBTHREAD@
 LIMITS_H = @LIMITS_H@
 LN_S = @LN_S@
 LOCALCHARSET_TESTS_ENVIRONMENT = @LOCALCHARSET_TESTS_ENVIRONMENT@
@@ -1125,7 +1135,10 @@ 
 LOCALE_JA = @LOCALE_JA@
 LOCALE_ZH_CN = @LOCALE_ZH_CN@
 LTLIBINTL = @LTLIBINTL@
+LTLIBMULTITHREAD = @LTLIBMULTITHREAD@
 LTLIBOBJS = @LTLIBOBJS@
+LTLIBPTH = @LTLIBPTH@
+LTLIBTHREAD = @LTLIBTHREAD@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
 MKDIR_P = @MKDIR_P@
diff --git a/gnulib/aclocal.m4 b/gnulib/aclocal.m4
index 911623e..34580d8 100644
--- a/gnulib/aclocal.m4
+++ b/gnulib/aclocal.m4
@@ -1774,11 +1774,15 @@ 
 m4_include([import/m4/isnand.m4])
 m4_include([import/m4/isnanl.m4])
 m4_include([import/m4/largefile.m4])
+m4_include([import/m4/lib-ld.m4])
+m4_include([import/m4/lib-link.m4])
+m4_include([import/m4/lib-prefix.m4])
 m4_include([import/m4/limits-h.m4])
 m4_include([import/m4/localcharset.m4])
 m4_include([import/m4/locale-fr.m4])
 m4_include([import/m4/locale-ja.m4])
 m4_include([import/m4/locale-zh.m4])
+m4_include([import/m4/lock.m4])
 m4_include([import/m4/longlong.m4])
 m4_include([import/m4/lstat.m4])
 m4_include([import/m4/malloc.m4])
@@ -1832,6 +1836,7 @@ 
 m4_include([import/m4/strchrnul.m4])
 m4_include([import/m4/strdup.m4])
 m4_include([import/m4/strerror.m4])
+m4_include([import/m4/strerror_r.m4])
 m4_include([import/m4/string_h.m4])
 m4_include([import/m4/strstr.m4])
 m4_include([import/m4/strtok_r.m4])
@@ -1841,6 +1846,7 @@ 
 m4_include([import/m4/sys_types_h.m4])
 m4_include([import/m4/sys_uio_h.m4])
 m4_include([import/m4/tempname.m4])
+m4_include([import/m4/threadlib.m4])
 m4_include([import/m4/time_h.m4])
 m4_include([import/m4/unistd-safer.m4])
 m4_include([import/m4/unistd_h.m4])
diff --git a/gnulib/config.in b/gnulib/config.in
index b0ba800..727fb4f 100644
--- a/gnulib/config.in
+++ b/gnulib/config.in
@@ -96,6 +96,10 @@ 
 #undef GNULIB_GETCWD
 
 /* Define to a C preprocessor expression that evaluates to 1 or 0, depending
+   whether the gnulib module lock shall be considered present. */
+#undef GNULIB_LOCK
+
+/* Define to a C preprocessor expression that evaluates to 1 or 0, depending
    whether the gnulib module mkostemp shall be considered present. */
 #undef GNULIB_MKOSTEMP
 
@@ -260,6 +264,9 @@ 
 /* Define to 1 when the gnulib module strerror should be tested. */
 #undef GNULIB_TEST_STRERROR
 
+/* Define to 1 when the gnulib module strerror_r should be tested. */
+#undef GNULIB_TEST_STRERROR_R
+
 /* Define to 1 when the gnulib module strstr should be tested. */
 #undef GNULIB_TEST_STRSTR
 
@@ -289,6 +296,9 @@ 
 /* Define to 1 if you have the 'canonicalize_file_name' function. */
 #undef HAVE_CANONICALIZE_FILE_NAME
 
+/* Define to 1 if you have the 'catgets' function. */
+#undef HAVE_CATGETS
+
 /* Define to 1 if you have the `closedir' function. */
 #undef HAVE_CLOSEDIR
 
@@ -372,10 +382,13 @@ 
    */
 #undef HAVE_DECL_STRDUP
 
-/* Define to 1 if you have the declaration of `strerror_r', and to 0 if you
-   don't. */
+/* Define to 1, since you should have the declaration of strerror_r. */
 #undef HAVE_DECL_STRERROR_R
 
+/* Define to 1 if you have the declaration of 'strerror_r' in the system
+   include files, or to 0 otherwise. */
+#undef HAVE_DECL_STRERROR_R_ORIG
+
 /* Define to 1 if you have the declaration of `strtok_r', and to 0 if you
    don't. */
 #undef HAVE_DECL_STRTOK_R
@@ -586,6 +599,12 @@ 
 /* Define to 1 if you have the 'pipe' function. */
 #undef HAVE_PIPE
 
+/* Define if the <pthread.h> defines PTHREAD_MUTEX_RECURSIVE. */
+#undef HAVE_PTHREAD_MUTEX_RECURSIVE
+
+/* Define if the POSIX multithreading library has read/write locks. */
+#undef HAVE_PTHREAD_RWLOCK
+
 /* Define to 1 if you have the `rawmemchr' function. */
 #undef HAVE_RAWMEMCHR
 
@@ -1511,6 +1530,9 @@ 
 /* Define to 1 if the system has the type `sigset_t'. */
 #undef HAVE_SIGSET_T
 
+/* Define to 1 if you have the 'snprintf' function. */
+#undef HAVE_SNPRINTF
+
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
@@ -1523,7 +1545,7 @@ 
 /* Define to 1 if you have the 'strdup' function. */
 #undef HAVE_STRDUP
 
-/* Define to 1 if you have the `strerror_r' function. */
+/* Define to 1, since you should have the function strerror_r. */
 #undef HAVE_STRERROR_R
 
 /* Define to 1 if you have the <strings.h> header file. */
@@ -1651,6 +1673,9 @@ 
 /* Define to 1 if you have the `__secure_getenv' function. */
 #undef HAVE___SECURE_GETENV
 
+/* Define to 1 if you have the '__xpg_strerror_r' function. */
+#undef HAVE___XPG_STRERROR_R
+
 /* Define as the bit index in the word where to find bit 0 of the exponent of
    'long double'. */
 #undef LDBL_EXPBIT0_BIT
@@ -1718,6 +1743,9 @@ 
    type mode_t. */
 #undef PROMOTED_MODE_T
 
+/* Define if the pthread_in_use() detection is hard. */
+#undef PTHREAD_IN_USE_DETECTION_HARD
+
 /* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
    'ptrdiff_t'. */
 #undef PTRDIFF_T_SUFFIX
@@ -1784,9 +1812,30 @@ 
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
-/* Define to 1 if strerror_r returns char *. */
+/* Define to 0, since strerror_r should not return char *. */
 #undef STRERROR_R_CHAR_P
 
+/* Define if the POSIX multithreading library can be used. */
+#undef USE_POSIX_THREADS
+
+/* Define if references to the POSIX multithreading library should be made
+   weak. */
+#undef USE_POSIX_THREADS_WEAK
+
+/* Define if the GNU Pth multithreading library can be used. */
+#undef USE_PTH_THREADS
+
+/* Define if references to the GNU Pth multithreading library should be made
+   weak. */
+#undef USE_PTH_THREADS_WEAK
+
+/* Define if the old Solaris multithreading library can be used. */
+#undef USE_SOLARIS_THREADS
+
+/* Define if references to the old Solaris multithreading library should be
+   made weak. */
+#undef USE_SOLARIS_THREADS_WEAK
+
 /* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
@@ -1847,6 +1896,9 @@ 
 #endif
 
 
+/* Define if the native Windows multithreading API can be used. */
+#undef USE_WINDOWS_THREADS
+
 /* Define to 1 if unsetenv returns void instead of int. */
 #undef VOID_UNSETENV
 
diff --git a/gnulib/configure b/gnulib/configure
index a551e22..9749a49 100644
--- a/gnulib/configure
+++ b/gnulib/configure
@@ -619,6 +619,7 @@ 
 # include <unistd.h>
 #endif"
 
+gl_use_threads_default=
 gl_header_list=
 gl_func_list=
 gl_fnmatch_required=POSIX
@@ -1035,6 +1036,13 @@ 
 GNULIB_BTOWC
 NEXT_AS_FIRST_DIRECTIVE_MATH_H
 NEXT_MATH_H
+LTLIBMULTITHREAD
+LIBMULTITHREAD
+LTLIBTHREAD
+LIBTHREAD
+LIBPTH_PREFIX
+LTLIBPTH
+LIBPTH
 LOCALCHARSET_TESTS_ENVIRONMENT
 GLIBC21
 NEXT_AS_FIRST_DIRECTIVE_INTTYPES_H
@@ -1775,7 +1783,11 @@ 
 enable_option_checking
 enable_maintainer_mode
 enable_largefile
+enable_threads
 enable_plugins
+with_gnu_ld
+enable_rpath
+with_libpth_prefix
 enable_dependency_tracking
 enable_silent_rules
 '
@@ -2411,7 +2423,11 @@ 
                           enable make rules and dependencies not useful (and
                           sometimes confusing) to the casual installer
   --disable-largefile     omit support for large files
+  --enable-threads={posix|solaris|pth|windows}
+                          specify multithreading API
+  --disable-threads       build without multithread safety
   --enable-plugins        Enable support for plugins
+  --disable-rpath         do not hardcode runtime library paths
   --enable-dependency-tracking
                           do not reject slow dependency extractors
   --disable-dependency-tracking
@@ -2419,6 +2435,13 @@ 
   --enable-silent-rules   less verbose build output (undo: "make V=1")
   --disable-silent-rules  verbose build output (undo: "make V=0")
 
+Optional Packages:
+  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
+  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
+  --with-libpth-prefix[=DIR]  search for libpth in DIR/include and DIR/lib
+  --without-libpth-prefix     don't search for libpth in includedir and libdir
+
 Some influential environment variables:
   CC          C compiler command
   CFLAGS      C compiler flags
@@ -3537,6 +3560,9 @@ 
 gl_func_list="$gl_func_list getegid"
 gl_func_list="$gl_func_list setenv"
 gl_func_list="$gl_func_list strdup"
+gl_func_list="$gl_func_list __xpg_strerror_r"
+gl_func_list="$gl_func_list catgets"
+gl_func_list="$gl_func_list snprintf"
 gl_header_list="$gl_header_list sys/uio.h"
 gl_func_list="$gl_func_list pipe"
 gl_func_list="$gl_func_list iswcntrl"
@@ -3615,6 +3641,8 @@ 
 ac_config_headers="$ac_config_headers config.h:config.in"
 
 
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable maintainer-specific portions of Makefiles" >&5
 $as_echo_n "checking whether to enable maintainer-specific portions of Makefiles... " >&6; }
     # Check whether --enable-maintainer-mode was given.
@@ -5459,6 +5487,7 @@ 
   fi
 
 
+
 # Make sure we can run config.sub.
 $SHELL "$ac_aux_dir/config.sub" sun4 >/dev/null 2>&1 ||
   as_fn_error $? "cannot run $SHELL $ac_aux_dir/config.sub" "$LINENO" 5
@@ -5763,10 +5792,59 @@ 
 
 
 
+
+
+
+  # Check whether --enable-threads was given.
+if test "${enable_threads+set}" = set; then :
+  enableval=$enable_threads; gl_use_threads=$enableval
+else
+  if test -n "$gl_use_threads_default"; then
+       gl_use_threads="$gl_use_threads_default"
+     else
+       case "$host_os" in
+                                                               osf*) gl_use_threads=no ;;
+         cygwin*)
+               case `uname -r` in
+                 1.[0-5].*) gl_use_threads=no ;;
+                 *)         gl_use_threads=yes ;;
+               esac
+               ;;
+         *)    gl_use_threads=yes ;;
+       esac
+     fi
+
+fi
+
+  if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+    # For using <pthread.h>:
+    case "$host_os" in
+      osf*)
+        # On OSF/1, the compiler needs the flag -D_REENTRANT so that it
+        # groks <pthread.h>. cc also understands the flag -pthread, but
+        # we don't use it because 1. gcc-2.95 doesn't understand -pthread,
+        # 2. putting a flag into CPPFLAGS that has an effect on the linker
+        # causes the AC_LINK_IFELSE test below to succeed unexpectedly,
+        # leading to wrong values of LIBTHREAD and LTLIBTHREAD.
+        CPPFLAGS="$CPPFLAGS -D_REENTRANT"
+        ;;
+    esac
+    # Some systems optimize for single-threaded programs by default, and
+    # need special flags to disable these optimizations. For example, the
+    # definition of 'errno' in <errno.h>.
+    case "$host_os" in
+      aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;;
+      solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;;
+    esac
+  fi
+
+
+
   # Pre-early section.
 
 
 
+
   # Code from module absolute-header:
   # Code from module alloca:
   # Code from module alloca-opt:
@@ -5822,6 +5900,7 @@ 
   # Code from module gettimeofday:
   # Code from module glob:
   # Code from module hard-locale:
+  # Code from module havelib:
   # Code from module include_next:
   # Code from module inet_ntop:
   # Code from module intprops:
@@ -5833,6 +5912,7 @@ 
 
   # Code from module limits-h:
   # Code from module localcharset:
+  # Code from module lock:
   # Code from module lstat:
   # Code from module malloc-posix:
   # Code from module malloca:
@@ -5889,6 +5969,7 @@ 
   # Code from module streq:
   # Code from module strerror:
   # Code from module strerror-override:
+  # Code from module strerror_r-posix:
   # Code from module string:
   # Code from module strnlen1:
   # Code from module strstr:
@@ -5900,6 +5981,10 @@ 
   # Code from module sys_types:
   # Code from module sys_uio:
   # Code from module tempname:
+  # Code from module threadlib:
+
+
+
   # Code from module time:
   # Code from module unistd:
   # Code from module unistd-safer:
@@ -8351,97 +8436,16 @@ 
   fi
 
 
-ac_fn_c_check_decl "$LINENO" "strerror_r" "ac_cv_have_decl_strerror_r" "$ac_includes_default"
-if test "x$ac_cv_have_decl_strerror_r" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
 
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_STRERROR_R $ac_have_decl
-_ACEOF
 
-for ac_func in strerror_r
-do :
-  ac_fn_c_check_func "$LINENO" "strerror_r" "ac_cv_func_strerror_r"
-if test "x$ac_cv_func_strerror_r" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_STRERROR_R 1
-_ACEOF
+$as_echo "#define HAVE_DECL_STRERROR_R 1" >>confdefs.h
 
-fi
-done
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether strerror_r returns char *" >&5
-$as_echo_n "checking whether strerror_r returns char *... " >&6; }
-if ${ac_cv_func_strerror_r_char_p+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
+$as_echo "#define HAVE_STRERROR_R 1" >>confdefs.h
 
-    ac_cv_func_strerror_r_char_p=no
-    if test $ac_cv_have_decl_strerror_r = yes; then
-      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$ac_includes_default
-int
-main ()
-{
 
-	  char buf[100];
-	  char x = *strerror_r (0, buf, sizeof buf);
-	  char *p = strerror_r (0, buf, sizeof buf);
-	  return !p || x;
+$as_echo "#define STRERROR_R_CHAR_P 0" >>confdefs.h
 
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_func_strerror_r_char_p=yes
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-    else
-      # strerror_r is not declared.  Choose between
-      # systems that have relatively inaccessible declarations for the
-      # function.  BeOS and DEC UNIX 4.0 fall in this category, but the
-      # former has a strerror_r that returns char*, while the latter
-      # has a strerror_r that returns `int'.
-      # This test should segfault on the DEC system.
-      if test "$cross_compiling" = yes; then :
-  :
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$ac_includes_default
-	extern char *strerror_r ();
-int
-main ()
-{
-char buf[100];
-	  char x = *strerror_r (0, buf, sizeof buf);
-	  return ! isalpha (x);
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
-  ac_cv_func_strerror_r_char_p=yes
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
-fi
-
-    fi
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_strerror_r_char_p" >&5
-$as_echo "$ac_cv_func_strerror_r_char_p" >&6; }
-if test $ac_cv_func_strerror_r_char_p = yes; then
-
-$as_echo "#define STRERROR_R_CHAR_P 1" >>confdefs.h
-
-fi
 
 
   XGETTEXT_EXTRA_OPTIONS=
@@ -12504,6 +12508,1159 @@ 
 
 
 
+      if test "X$prefix" = "XNONE"; then
+    acl_final_prefix="$ac_default_prefix"
+  else
+    acl_final_prefix="$prefix"
+  fi
+  if test "X$exec_prefix" = "XNONE"; then
+    acl_final_exec_prefix='${prefix}'
+  else
+    acl_final_exec_prefix="$exec_prefix"
+  fi
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  eval acl_final_exec_prefix=\"$acl_final_exec_prefix\"
+  prefix="$acl_save_prefix"
+
+
+
+# Check whether --with-gnu-ld was given.
+if test "${with_gnu_ld+set}" = set; then :
+  withval=$with_gnu_ld; test "$withval" = no || with_gnu_ld=yes
+else
+  with_gnu_ld=no
+fi
+
+# Prepare PATH_SEPARATOR.
+# The user is always right.
+if test "${PATH_SEPARATOR+set}" != set; then
+  # Determine PATH_SEPARATOR by trying to find /bin/sh in a PATH which
+  # contains only /bin. Note that ksh looks also at the FPATH variable,
+  # so we have to set that as well for the test.
+  PATH_SEPARATOR=:
+  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+    && { (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+           || PATH_SEPARATOR=';'
+       }
+fi
+
+ac_prog=ld
+if test "$GCC" = yes; then
+  # Check if gcc -print-prog-name=ld gives a path.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ld used by $CC" >&5
+$as_echo_n "checking for ld used by $CC... " >&6; }
+  case $host in
+  *-*-mingw*)
+    # gcc leaves a trailing carriage return which upsets mingw
+    ac_prog=`($CC -print-prog-name=ld) 2>&5 | tr -d '\015'` ;;
+  *)
+    ac_prog=`($CC -print-prog-name=ld) 2>&5` ;;
+  esac
+  case $ac_prog in
+    # Accept absolute paths.
+    [\\/]* | ?:[\\/]*)
+      re_direlt='/[^/][^/]*/\.\./'
+      # Canonicalize the pathname of ld
+      ac_prog=`echo "$ac_prog"| sed 's%\\\\%/%g'`
+      while echo "$ac_prog" | grep "$re_direlt" > /dev/null 2>&1; do
+        ac_prog=`echo $ac_prog| sed "s%$re_direlt%/%"`
+      done
+      test -z "$LD" && LD="$ac_prog"
+      ;;
+  "")
+    # If it fails, then pretend we aren't using GCC.
+    ac_prog=ld
+    ;;
+  *)
+    # If it is relative, then search for the first ld in PATH.
+    with_gnu_ld=unknown
+    ;;
+  esac
+elif test "$with_gnu_ld" = yes; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for GNU ld" >&5
+$as_echo_n "checking for GNU ld... " >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for non-GNU ld" >&5
+$as_echo_n "checking for non-GNU ld... " >&6; }
+fi
+if ${acl_cv_path_LD+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -z "$LD"; then
+  acl_save_ifs="$IFS"; IFS=$PATH_SEPARATOR
+  for ac_dir in $PATH; do
+    IFS="$acl_save_ifs"
+    test -z "$ac_dir" && ac_dir=.
+    if test -f "$ac_dir/$ac_prog" || test -f "$ac_dir/$ac_prog$ac_exeext"; then
+      acl_cv_path_LD="$ac_dir/$ac_prog"
+      # Check to see if the program is GNU ld.  I'd rather use --version,
+      # but apparently some variants of GNU ld only accept -v.
+      # Break only if it was the GNU/non-GNU ld that we prefer.
+      case `"$acl_cv_path_LD" -v 2>&1 </dev/null` in
+      *GNU* | *'with BFD'*)
+        test "$with_gnu_ld" != no && break
+        ;;
+      *)
+        test "$with_gnu_ld" != yes && break
+        ;;
+      esac
+    fi
+  done
+  IFS="$acl_save_ifs"
+else
+  acl_cv_path_LD="$LD" # Let the user override the test with a path.
+fi
+fi
+
+LD="$acl_cv_path_LD"
+if test -n "$LD"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LD" >&5
+$as_echo "$LD" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+test -z "$LD" && as_fn_error $? "no acceptable ld found in \$PATH" "$LINENO" 5
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if the linker ($LD) is GNU ld" >&5
+$as_echo_n "checking if the linker ($LD) is GNU ld... " >&6; }
+if ${acl_cv_prog_gnu_ld+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  # I'd rather use --version here, but apparently some GNU lds only accept -v.
+case `$LD -v 2>&1 </dev/null` in
+*GNU* | *'with BFD'*)
+  acl_cv_prog_gnu_ld=yes
+  ;;
+*)
+  acl_cv_prog_gnu_ld=no
+  ;;
+esac
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $acl_cv_prog_gnu_ld" >&5
+$as_echo "$acl_cv_prog_gnu_ld" >&6; }
+with_gnu_ld=$acl_cv_prog_gnu_ld
+
+
+
+
+                                                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for shared library run path origin" >&5
+$as_echo_n "checking for shared library run path origin... " >&6; }
+if ${acl_cv_rpath+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+    CC="$CC" GCC="$GCC" LDFLAGS="$LDFLAGS" LD="$LD" with_gnu_ld="$with_gnu_ld" \
+    ${CONFIG_SHELL-/bin/sh} "$ac_aux_dir/config.rpath" "$host" > conftest.sh
+    . ./conftest.sh
+    rm -f ./conftest.sh
+    acl_cv_rpath=done
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $acl_cv_rpath" >&5
+$as_echo "$acl_cv_rpath" >&6; }
+  wl="$acl_cv_wl"
+  acl_libext="$acl_cv_libext"
+  acl_shlibext="$acl_cv_shlibext"
+  acl_libname_spec="$acl_cv_libname_spec"
+  acl_library_names_spec="$acl_cv_library_names_spec"
+  acl_hardcode_libdir_flag_spec="$acl_cv_hardcode_libdir_flag_spec"
+  acl_hardcode_libdir_separator="$acl_cv_hardcode_libdir_separator"
+  acl_hardcode_direct="$acl_cv_hardcode_direct"
+  acl_hardcode_minus_L="$acl_cv_hardcode_minus_L"
+    # Check whether --enable-rpath was given.
+if test "${enable_rpath+set}" = set; then :
+  enableval=$enable_rpath; :
+else
+  enable_rpath=yes
+fi
+
+
+
+
+  acl_libdirstem=lib
+  acl_libdirstem2=
+  case "$host_os" in
+    solaris*)
+                                    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for 64-bit host" >&5
+$as_echo_n "checking for 64-bit host... " >&6; }
+if ${gl_cv_solaris_64bit+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#ifdef _LP64
+sixtyfour bits
+#endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "sixtyfour bits" >/dev/null 2>&1; then :
+  gl_cv_solaris_64bit=yes
+else
+  gl_cv_solaris_64bit=no
+fi
+rm -f conftest*
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_solaris_64bit" >&5
+$as_echo "$gl_cv_solaris_64bit" >&6; }
+      if test $gl_cv_solaris_64bit = yes; then
+        acl_libdirstem=lib/64
+        case "$host_cpu" in
+          sparc*)        acl_libdirstem2=lib/sparcv9 ;;
+          i*86 | x86_64) acl_libdirstem2=lib/amd64 ;;
+        esac
+      fi
+      ;;
+    *)
+      searchpath=`(LC_ALL=C $CC -print-search-dirs) 2>/dev/null | sed -n -e 's,^libraries: ,,p' | sed -e 's,^=,,'`
+      if test -n "$searchpath"; then
+        acl_save_IFS="${IFS= 	}"; IFS=":"
+        for searchdir in $searchpath; do
+          if test -d "$searchdir"; then
+            case "$searchdir" in
+              */lib64/ | */lib64 ) acl_libdirstem=lib64 ;;
+              */../ | */.. )
+                # Better ignore directories of this form. They are misleading.
+                ;;
+              *) searchdir=`cd "$searchdir" && pwd`
+                 case "$searchdir" in
+                   */lib64 ) acl_libdirstem=lib64 ;;
+                 esac ;;
+            esac
+          fi
+        done
+        IFS="$acl_save_IFS"
+      fi
+      ;;
+  esac
+  test -n "$acl_libdirstem2" || acl_libdirstem2="$acl_libdirstem"
+
+
+
+  gl_threads_api=none
+  LIBTHREAD=
+  LTLIBTHREAD=
+  LIBMULTITHREAD=
+  LTLIBMULTITHREAD=
+  if test "$gl_use_threads" != no; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether imported symbols can be declared weak" >&5
+$as_echo_n "checking whether imported symbols can be declared weak... " >&6; }
+if ${gl_cv_have_weak+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gl_cv_have_weak=no
+              cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern void xyzzy ();
+#pragma weak xyzzy
+int
+main ()
+{
+xyzzy();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_cv_have_weak=maybe
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+       if test $gl_cv_have_weak = maybe; then
+                           if test "$cross_compiling" = yes; then :
+                          cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#ifdef __ELF__
+               Extensible Linking Format
+               #endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "Extensible Linking Format" >/dev/null 2>&1; then :
+  gl_cv_have_weak="guessing yes"
+else
+  gl_cv_have_weak="guessing no"
+fi
+rm -f conftest*
+
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <stdio.h>
+#pragma weak fputs
+int main ()
+{
+  return (fputs == NULL);
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_have_weak=yes
+else
+  gl_cv_have_weak=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+       fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_have_weak" >&5
+$as_echo "$gl_cv_have_weak" >&6; }
+    if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+      # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
+      # it groks <pthread.h>. It's added above, in gl_THREADLIB_EARLY_BODY.
+      ac_fn_c_check_header_mongrel "$LINENO" "pthread.h" "ac_cv_header_pthread_h" "$ac_includes_default"
+if test "x$ac_cv_header_pthread_h" = xyes; then :
+  gl_have_pthread_h=yes
+else
+  gl_have_pthread_h=no
+fi
+
+
+      if test "$gl_have_pthread_h" = yes; then
+        # Other possible tests:
+        #   -lpthreads (FSU threads, PCthreads)
+        #   -lgthreads
+        gl_have_pthread=
+        # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
+        # in libc. IRIX 6.5 has the first one in both libc and libpthread, but
+        # the second one only in libpthread, and lock.c needs it.
+        #
+        # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
+        # needs -pthread for some reason.  See:
+        # http://lists.gnu.org/archive/html/bug-gnulib/2014-09/msg00023.html
+        save_LIBS=$LIBS
+        for gl_pthread in '' '-pthread'; do
+          LIBS="$LIBS $gl_pthread"
+          cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+                 pthread_mutex_t m;
+                 pthread_mutexattr_t ma;
+
+int
+main ()
+{
+pthread_mutex_lock (&m);
+                 pthread_mutexattr_init (&ma);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_have_pthread=yes
+             LIBTHREAD=$gl_pthread LTLIBTHREAD=$gl_pthread
+             LIBMULTITHREAD=$gl_pthread LTLIBMULTITHREAD=$gl_pthread
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+          LIBS=$save_LIBS
+          test -n "$gl_have_pthread" && break
+        done
+
+        # Test for libpthread by looking for pthread_kill. (Not pthread_self,
+        # since it is defined as a macro on OSF/1.)
+        if test -n "$gl_have_pthread" && test -z "$LIBTHREAD"; then
+          # The program links fine without libpthread. But it may actually
+          # need to link with libpthread in order to create multiple threads.
+          { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_kill in -lpthread" >&5
+$as_echo_n "checking for pthread_kill in -lpthread... " >&6; }
+if ${ac_cv_lib_pthread_pthread_kill+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpthread  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_kill ();
+int
+main ()
+{
+return pthread_kill ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_pthread_pthread_kill=yes
+else
+  ac_cv_lib_pthread_pthread_kill=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread_pthread_kill" >&5
+$as_echo "$ac_cv_lib_pthread_pthread_kill" >&6; }
+if test "x$ac_cv_lib_pthread_pthread_kill" = xyes; then :
+  LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread
+             # On Solaris and HP-UX, most pthread functions exist also in libc.
+             # Therefore pthread_in_use() needs to actually try to create a
+             # thread: pthread_create from libc will fail, whereas
+             # pthread_create will actually create a thread.
+             case "$host_os" in
+               solaris* | hpux*)
+
+$as_echo "#define PTHREAD_IN_USE_DETECTION_HARD 1" >>confdefs.h
+
+             esac
+
+fi
+
+        elif test -z "$gl_have_pthread"; then
+          # Some library is needed. Try libpthread and libc_r.
+          { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_kill in -lpthread" >&5
+$as_echo_n "checking for pthread_kill in -lpthread... " >&6; }
+if ${ac_cv_lib_pthread_pthread_kill+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpthread  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_kill ();
+int
+main ()
+{
+return pthread_kill ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_pthread_pthread_kill=yes
+else
+  ac_cv_lib_pthread_pthread_kill=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_pthread_pthread_kill" >&5
+$as_echo "$ac_cv_lib_pthread_pthread_kill" >&6; }
+if test "x$ac_cv_lib_pthread_pthread_kill" = xyes; then :
+  gl_have_pthread=yes
+             LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread
+             LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread
+fi
+
+          if test -z "$gl_have_pthread"; then
+            # For FreeBSD 4.
+            { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_kill in -lc_r" >&5
+$as_echo_n "checking for pthread_kill in -lc_r... " >&6; }
+if ${ac_cv_lib_c_r_pthread_kill+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lc_r  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_kill ();
+int
+main ()
+{
+return pthread_kill ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_c_r_pthread_kill=yes
+else
+  ac_cv_lib_c_r_pthread_kill=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_c_r_pthread_kill" >&5
+$as_echo "$ac_cv_lib_c_r_pthread_kill" >&6; }
+if test "x$ac_cv_lib_c_r_pthread_kill" = xyes; then :
+  gl_have_pthread=yes
+               LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r
+               LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r
+fi
+
+          fi
+        fi
+        if test -n "$gl_have_pthread"; then
+          gl_threads_api=posix
+
+$as_echo "#define USE_POSIX_THREADS 1" >>confdefs.h
+
+          if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+            if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+
+$as_echo "#define USE_POSIX_THREADS_WEAK 1" >>confdefs.h
+
+              LIBTHREAD=
+              LTLIBTHREAD=
+            fi
+          fi
+        fi
+      fi
+    fi
+    if test -z "$gl_have_pthread"; then
+      if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then
+        gl_have_solaristhread=
+        gl_save_LIBS="$LIBS"
+        LIBS="$LIBS -lthread"
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <thread.h>
+#include <synch.h>
+
+int
+main ()
+{
+thr_self();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_have_solaristhread=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+        LIBS="$gl_save_LIBS"
+        if test -n "$gl_have_solaristhread"; then
+          gl_threads_api=solaris
+          LIBTHREAD=-lthread
+          LTLIBTHREAD=-lthread
+          LIBMULTITHREAD="$LIBTHREAD"
+          LTLIBMULTITHREAD="$LTLIBTHREAD"
+
+$as_echo "#define USE_SOLARIS_THREADS 1" >>confdefs.h
+
+          if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+
+$as_echo "#define USE_SOLARIS_THREADS_WEAK 1" >>confdefs.h
+
+            LIBTHREAD=
+            LTLIBTHREAD=
+          fi
+        fi
+      fi
+    fi
+    if test "$gl_use_threads" = pth; then
+      gl_save_CPPFLAGS="$CPPFLAGS"
+
+
+
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking how to link with libpth" >&5
+$as_echo_n "checking how to link with libpth... " >&6; }
+if ${ac_cv_libpth_libs+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+
+
+
+
+
+
+
+    use_additional=yes
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+
+    eval additional_includedir=\"$includedir\"
+    eval additional_libdir=\"$libdir\"
+
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+
+# Check whether --with-libpth-prefix was given.
+if test "${with_libpth_prefix+set}" = set; then :
+  withval=$with_libpth_prefix;
+    if test "X$withval" = "Xno"; then
+      use_additional=no
+    else
+      if test "X$withval" = "X"; then
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+
+          eval additional_includedir=\"$includedir\"
+          eval additional_libdir=\"$libdir\"
+
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+      else
+        additional_includedir="$withval/include"
+        additional_libdir="$withval/$acl_libdirstem"
+        if test "$acl_libdirstem2" != "$acl_libdirstem" \
+           && ! test -d "$withval/$acl_libdirstem"; then
+          additional_libdir="$withval/$acl_libdirstem2"
+        fi
+      fi
+    fi
+
+fi
+
+      LIBPTH=
+  LTLIBPTH=
+  INCPTH=
+  LIBPTH_PREFIX=
+      HAVE_LIBPTH=
+  rpathdirs=
+  ltrpathdirs=
+  names_already_handled=
+  names_next_round='pth '
+  while test -n "$names_next_round"; do
+    names_this_round="$names_next_round"
+    names_next_round=
+    for name in $names_this_round; do
+      already_handled=
+      for n in $names_already_handled; do
+        if test "$n" = "$name"; then
+          already_handled=yes
+          break
+        fi
+      done
+      if test -z "$already_handled"; then
+        names_already_handled="$names_already_handled $name"
+                        uppername=`echo "$name" | sed -e 'y|abcdefghijklmnopqrstuvwxyz./+-|ABCDEFGHIJKLMNOPQRSTUVWXYZ____|'`
+        eval value=\"\$HAVE_LIB$uppername\"
+        if test -n "$value"; then
+          if test "$value" = yes; then
+            eval value=\"\$LIB$uppername\"
+            test -z "$value" || LIBPTH="${LIBPTH}${LIBPTH:+ }$value"
+            eval value=\"\$LTLIB$uppername\"
+            test -z "$value" || LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }$value"
+          else
+                                    :
+          fi
+        else
+                              found_dir=
+          found_la=
+          found_so=
+          found_a=
+          eval libname=\"$acl_libname_spec\"    # typically: libname=lib$name
+          if test -n "$acl_shlibext"; then
+            shrext=".$acl_shlibext"             # typically: shrext=.so
+          else
+            shrext=
+          fi
+          if test $use_additional = yes; then
+            dir="$additional_libdir"
+                                    if test -n "$acl_shlibext"; then
+              if test -f "$dir/$libname$shrext"; then
+                found_dir="$dir"
+                found_so="$dir/$libname$shrext"
+              else
+                if test "$acl_library_names_spec" = '$libname$shrext$versuffix'; then
+                  ver=`(cd "$dir" && \
+                        for f in "$libname$shrext".*; do echo "$f"; done \
+                        | sed -e "s,^$libname$shrext\\\\.,," \
+                        | sort -t '.' -n -r -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 \
+                        | sed 1q ) 2>/dev/null`
+                  if test -n "$ver" && test -f "$dir/$libname$shrext.$ver"; then
+                    found_dir="$dir"
+                    found_so="$dir/$libname$shrext.$ver"
+                  fi
+                else
+                  eval library_names=\"$acl_library_names_spec\"
+                  for f in $library_names; do
+                    if test -f "$dir/$f"; then
+                      found_dir="$dir"
+                      found_so="$dir/$f"
+                      break
+                    fi
+                  done
+                fi
+              fi
+            fi
+                        if test "X$found_dir" = "X"; then
+              if test -f "$dir/$libname.$acl_libext"; then
+                found_dir="$dir"
+                found_a="$dir/$libname.$acl_libext"
+              fi
+            fi
+            if test "X$found_dir" != "X"; then
+              if test -f "$dir/$libname.la"; then
+                found_la="$dir/$libname.la"
+              fi
+            fi
+          fi
+          if test "X$found_dir" = "X"; then
+            for x in $LDFLAGS $LTLIBPTH; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+              case "$x" in
+                -L*)
+                  dir=`echo "X$x" | sed -e 's/^X-L//'`
+                                    if test -n "$acl_shlibext"; then
+                    if test -f "$dir/$libname$shrext"; then
+                      found_dir="$dir"
+                      found_so="$dir/$libname$shrext"
+                    else
+                      if test "$acl_library_names_spec" = '$libname$shrext$versuffix'; then
+                        ver=`(cd "$dir" && \
+                              for f in "$libname$shrext".*; do echo "$f"; done \
+                              | sed -e "s,^$libname$shrext\\\\.,," \
+                              | sort -t '.' -n -r -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 \
+                              | sed 1q ) 2>/dev/null`
+                        if test -n "$ver" && test -f "$dir/$libname$shrext.$ver"; then
+                          found_dir="$dir"
+                          found_so="$dir/$libname$shrext.$ver"
+                        fi
+                      else
+                        eval library_names=\"$acl_library_names_spec\"
+                        for f in $library_names; do
+                          if test -f "$dir/$f"; then
+                            found_dir="$dir"
+                            found_so="$dir/$f"
+                            break
+                          fi
+                        done
+                      fi
+                    fi
+                  fi
+                                    if test "X$found_dir" = "X"; then
+                    if test -f "$dir/$libname.$acl_libext"; then
+                      found_dir="$dir"
+                      found_a="$dir/$libname.$acl_libext"
+                    fi
+                  fi
+                  if test "X$found_dir" != "X"; then
+                    if test -f "$dir/$libname.la"; then
+                      found_la="$dir/$libname.la"
+                    fi
+                  fi
+                  ;;
+              esac
+              if test "X$found_dir" != "X"; then
+                break
+              fi
+            done
+          fi
+          if test "X$found_dir" != "X"; then
+                        LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }-L$found_dir -l$name"
+            if test "X$found_so" != "X"; then
+                                                        if test "$enable_rpath" = no \
+                 || test "X$found_dir" = "X/usr/$acl_libdirstem" \
+                 || test "X$found_dir" = "X/usr/$acl_libdirstem2"; then
+                                LIBPTH="${LIBPTH}${LIBPTH:+ }$found_so"
+              else
+                                                                                haveit=
+                for x in $ltrpathdirs; do
+                  if test "X$x" = "X$found_dir"; then
+                    haveit=yes
+                    break
+                  fi
+                done
+                if test -z "$haveit"; then
+                  ltrpathdirs="$ltrpathdirs $found_dir"
+                fi
+                                if test "$acl_hardcode_direct" = yes; then
+                                                      LIBPTH="${LIBPTH}${LIBPTH:+ }$found_so"
+                else
+                  if test -n "$acl_hardcode_libdir_flag_spec" && test "$acl_hardcode_minus_L" = no; then
+                                                            LIBPTH="${LIBPTH}${LIBPTH:+ }$found_so"
+                                                            haveit=
+                    for x in $rpathdirs; do
+                      if test "X$x" = "X$found_dir"; then
+                        haveit=yes
+                        break
+                      fi
+                    done
+                    if test -z "$haveit"; then
+                      rpathdirs="$rpathdirs $found_dir"
+                    fi
+                  else
+                                                                                haveit=
+                    for x in $LDFLAGS $LIBPTH; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+                      if test "X$x" = "X-L$found_dir"; then
+                        haveit=yes
+                        break
+                      fi
+                    done
+                    if test -z "$haveit"; then
+                      LIBPTH="${LIBPTH}${LIBPTH:+ }-L$found_dir"
+                    fi
+                    if test "$acl_hardcode_minus_L" != no; then
+                                                                                        LIBPTH="${LIBPTH}${LIBPTH:+ }$found_so"
+                    else
+                                                                                                                                                                                LIBPTH="${LIBPTH}${LIBPTH:+ }-l$name"
+                    fi
+                  fi
+                fi
+              fi
+            else
+              if test "X$found_a" != "X"; then
+                                LIBPTH="${LIBPTH}${LIBPTH:+ }$found_a"
+              else
+                                                LIBPTH="${LIBPTH}${LIBPTH:+ }-L$found_dir -l$name"
+              fi
+            fi
+                        additional_includedir=
+            case "$found_dir" in
+              */$acl_libdirstem | */$acl_libdirstem/)
+                basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e "s,/$acl_libdirstem/"'*$,,'`
+                if test "$name" = 'pth'; then
+                  LIBPTH_PREFIX="$basedir"
+                fi
+                additional_includedir="$basedir/include"
+                ;;
+              */$acl_libdirstem2 | */$acl_libdirstem2/)
+                basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e "s,/$acl_libdirstem2/"'*$,,'`
+                if test "$name" = 'pth'; then
+                  LIBPTH_PREFIX="$basedir"
+                fi
+                additional_includedir="$basedir/include"
+                ;;
+            esac
+            if test "X$additional_includedir" != "X"; then
+                                                                                                                if test "X$additional_includedir" != "X/usr/include"; then
+                haveit=
+                if test "X$additional_includedir" = "X/usr/local/include"; then
+                  if test -n "$GCC"; then
+                    case $host_os in
+                      linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+                    esac
+                  fi
+                fi
+                if test -z "$haveit"; then
+                  for x in $CPPFLAGS $INCPTH; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+                    if test "X$x" = "X-I$additional_includedir"; then
+                      haveit=yes
+                      break
+                    fi
+                  done
+                  if test -z "$haveit"; then
+                    if test -d "$additional_includedir"; then
+                                            INCPTH="${INCPTH}${INCPTH:+ }-I$additional_includedir"
+                    fi
+                  fi
+                fi
+              fi
+            fi
+                        if test -n "$found_la"; then
+                                                        save_libdir="$libdir"
+              case "$found_la" in
+                */* | *\\*) . "$found_la" ;;
+                *) . "./$found_la" ;;
+              esac
+              libdir="$save_libdir"
+                            for dep in $dependency_libs; do
+                case "$dep" in
+                  -L*)
+                    additional_libdir=`echo "X$dep" | sed -e 's/^X-L//'`
+                                                                                                                                                                if test "X$additional_libdir" != "X/usr/$acl_libdirstem" \
+                       && test "X$additional_libdir" != "X/usr/$acl_libdirstem2"; then
+                      haveit=
+                      if test "X$additional_libdir" = "X/usr/local/$acl_libdirstem" \
+                         || test "X$additional_libdir" = "X/usr/local/$acl_libdirstem2"; then
+                        if test -n "$GCC"; then
+                          case $host_os in
+                            linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+                          esac
+                        fi
+                      fi
+                      if test -z "$haveit"; then
+                        haveit=
+                        for x in $LDFLAGS $LIBPTH; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+                          if test "X$x" = "X-L$additional_libdir"; then
+                            haveit=yes
+                            break
+                          fi
+                        done
+                        if test -z "$haveit"; then
+                          if test -d "$additional_libdir"; then
+                                                        LIBPTH="${LIBPTH}${LIBPTH:+ }-L$additional_libdir"
+                          fi
+                        fi
+                        haveit=
+                        for x in $LDFLAGS $LTLIBPTH; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+                          if test "X$x" = "X-L$additional_libdir"; then
+                            haveit=yes
+                            break
+                          fi
+                        done
+                        if test -z "$haveit"; then
+                          if test -d "$additional_libdir"; then
+                                                        LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }-L$additional_libdir"
+                          fi
+                        fi
+                      fi
+                    fi
+                    ;;
+                  -R*)
+                    dir=`echo "X$dep" | sed -e 's/^X-R//'`
+                    if test "$enable_rpath" != no; then
+                                                                  haveit=
+                      for x in $rpathdirs; do
+                        if test "X$x" = "X$dir"; then
+                          haveit=yes
+                          break
+                        fi
+                      done
+                      if test -z "$haveit"; then
+                        rpathdirs="$rpathdirs $dir"
+                      fi
+                                                                  haveit=
+                      for x in $ltrpathdirs; do
+                        if test "X$x" = "X$dir"; then
+                          haveit=yes
+                          break
+                        fi
+                      done
+                      if test -z "$haveit"; then
+                        ltrpathdirs="$ltrpathdirs $dir"
+                      fi
+                    fi
+                    ;;
+                  -l*)
+                                        names_next_round="$names_next_round "`echo "X$dep" | sed -e 's/^X-l//'`
+                    ;;
+                  *.la)
+                                                                                names_next_round="$names_next_round "`echo "X$dep" | sed -e 's,^X.*/,,' -e 's,^lib,,' -e 's,\.la$,,'`
+                    ;;
+                  *)
+                                        LIBPTH="${LIBPTH}${LIBPTH:+ }$dep"
+                    LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }$dep"
+                    ;;
+                esac
+              done
+            fi
+          else
+                                                            LIBPTH="${LIBPTH}${LIBPTH:+ }-l$name"
+            LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }-l$name"
+          fi
+        fi
+      fi
+    done
+  done
+  if test "X$rpathdirs" != "X"; then
+    if test -n "$acl_hardcode_libdir_separator"; then
+                        alldirs=
+      for found_dir in $rpathdirs; do
+        alldirs="${alldirs}${alldirs:+$acl_hardcode_libdir_separator}$found_dir"
+      done
+            acl_save_libdir="$libdir"
+      libdir="$alldirs"
+      eval flag=\"$acl_hardcode_libdir_flag_spec\"
+      libdir="$acl_save_libdir"
+      LIBPTH="${LIBPTH}${LIBPTH:+ }$flag"
+    else
+            for found_dir in $rpathdirs; do
+        acl_save_libdir="$libdir"
+        libdir="$found_dir"
+        eval flag=\"$acl_hardcode_libdir_flag_spec\"
+        libdir="$acl_save_libdir"
+        LIBPTH="${LIBPTH}${LIBPTH:+ }$flag"
+      done
+    fi
+  fi
+  if test "X$ltrpathdirs" != "X"; then
+            for found_dir in $ltrpathdirs; do
+      LTLIBPTH="${LTLIBPTH}${LTLIBPTH:+ }-R$found_dir"
+    done
+  fi
+
+
+
+
+
+
+    ac_cv_libpth_libs="$LIBPTH"
+    ac_cv_libpth_ltlibs="$LTLIBPTH"
+    ac_cv_libpth_cppflags="$INCPTH"
+    ac_cv_libpth_prefix="$LIBPTH_PREFIX"
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_libpth_libs" >&5
+$as_echo "$ac_cv_libpth_libs" >&6; }
+  LIBPTH="$ac_cv_libpth_libs"
+  LTLIBPTH="$ac_cv_libpth_ltlibs"
+  INCPTH="$ac_cv_libpth_cppflags"
+  LIBPTH_PREFIX="$ac_cv_libpth_prefix"
+
+  for element in $INCPTH; do
+    haveit=
+    for x in $CPPFLAGS; do
+
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  eval x=\"$x\"
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+
+      if test "X$x" = "X$element"; then
+        haveit=yes
+        break
+      fi
+    done
+    if test -z "$haveit"; then
+      CPPFLAGS="${CPPFLAGS}${CPPFLAGS:+ }$element"
+    fi
+  done
+
+
+
+
+      HAVE_LIBPTH=yes
+
+
+
+      gl_have_pth=
+      gl_save_LIBS="$LIBS"
+      LIBS="$LIBS $LIBPTH"
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pth.h>
+int
+main ()
+{
+pth_self();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_have_pth=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+      LIBS="$gl_save_LIBS"
+      if test -n "$gl_have_pth"; then
+        gl_threads_api=pth
+        LIBTHREAD="$LIBPTH"
+        LTLIBTHREAD="$LTLIBPTH"
+        LIBMULTITHREAD="$LIBTHREAD"
+        LTLIBMULTITHREAD="$LTLIBTHREAD"
+
+$as_echo "#define USE_PTH_THREADS 1" >>confdefs.h
+
+        if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+          if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+
+$as_echo "#define USE_PTH_THREADS_WEAK 1" >>confdefs.h
+
+            LIBTHREAD=
+            LTLIBTHREAD=
+          fi
+        fi
+      else
+        CPPFLAGS="$gl_save_CPPFLAGS"
+      fi
+    fi
+    if test -z "$gl_have_pthread"; then
+      case "$gl_use_threads" in
+        yes | windows | win32) # The 'win32' is for backward compatibility.
+          if { case "$host_os" in
+                 mingw*) true;;
+                 *) false;;
+               esac
+             }; then
+            gl_threads_api=windows
+
+$as_echo "#define USE_WINDOWS_THREADS 1" >>confdefs.h
+
+          fi
+          ;;
+      esac
+    fi
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for multithread API to use" >&5
+$as_echo_n "checking for multithread API to use... " >&6; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_threads_api" >&5
+$as_echo "$gl_threads_api" >&6; }
+
+
+
+
+
+
+
+
+
+
 
 
 
@@ -14199,6 +15356,196 @@ 
 
 
 
+  ac_fn_c_check_func "$LINENO" "strerror_r" "ac_cv_func_strerror_r"
+if test "x$ac_cv_func_strerror_r" = xyes; then :
+
+fi
+
+  if test $ac_cv_func_strerror_r = yes; then
+    if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
+                        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for strerror_r with POSIX signature" >&5
+$as_echo_n "checking for strerror_r with POSIX signature... " >&6; }
+if ${gl_cv_func_strerror_r_posix_signature+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <string.h>
+                int strerror_r (int, char *, size_t);
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gl_cv_func_strerror_r_posix_signature=yes
+else
+  gl_cv_func_strerror_r_posix_signature=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_strerror_r_posix_signature" >&5
+$as_echo "$gl_cv_func_strerror_r_posix_signature" >&6; }
+      if test $gl_cv_func_strerror_r_posix_signature = yes; then
+                                                        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether strerror_r works" >&5
+$as_echo_n "checking whether strerror_r works... " >&6; }
+if ${gl_cv_func_strerror_r_works+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+
+              case "$host_os" in
+                       # Guess no on AIX.
+                aix*)  gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess no on HP-UX.
+                hpux*) gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess no on BSD variants.
+                *bsd*)  gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess yes otherwise.
+                *)     gl_cv_func_strerror_r_works="guessing yes";;
+              esac
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <errno.h>
+                  #include <string.h>
+
+int
+main ()
+{
+int result = 0;
+                  char buf[79];
+                  if (strerror_r (EACCES, buf, 0) < 0)
+                    result |= 1;
+                  errno = 0;
+                  if (strerror_r (EACCES, buf, sizeof buf) != 0)
+                    result |= 2;
+                  strcpy (buf, "Unknown");
+                  if (strerror_r (0, buf, sizeof buf) != 0)
+                    result |= 4;
+                  if (errno)
+                    result |= 8;
+                  if (strstr (buf, "nknown") || strstr (buf, "ndefined"))
+                    result |= 0x10;
+                  errno = 0;
+                  *buf = 0;
+                  if (strerror_r (-3, buf, sizeof buf) < 0)
+                    result |= 0x20;
+                  if (errno)
+                    result |= 0x40;
+                  if (!*buf)
+                    result |= 0x80;
+                  return result;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_strerror_r_works=yes
+else
+  gl_cv_func_strerror_r_works=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_strerror_r_works" >&5
+$as_echo "$gl_cv_func_strerror_r_works" >&6; }
+      else
+
+  :
+
+
+
+
+
+                        if test $ac_cv_func___xpg_strerror_r = yes; then
+          { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether __xpg_strerror_r works" >&5
+$as_echo_n "checking whether __xpg_strerror_r works... " >&6; }
+if ${gl_cv_func_strerror_r_works+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+                                  gl_cv_func_strerror_r_works="guessing no"
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <errno.h>
+                    #include <string.h>
+                    extern
+                    #ifdef __cplusplus
+                    "C"
+                    #endif
+                    int __xpg_strerror_r(int, char *, size_t);
+
+int
+main ()
+{
+int result = 0;
+                    char buf[256] = "^";
+                    char copy[256];
+                    char *str = strerror (-1);
+                    strcpy (copy, str);
+                    if (__xpg_strerror_r (-2, buf, 1) == 0)
+                      result |= 1;
+                    if (*buf)
+                      result |= 2;
+                    __xpg_strerror_r (-2, buf, 256);
+                    if (strcmp (str, copy))
+                      result |= 4;
+                    return result;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_strerror_r_works=yes
+else
+  gl_cv_func_strerror_r_works=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_strerror_r_works" >&5
+$as_echo "$gl_cv_func_strerror_r_works" >&6; }
+        fi
+      fi
+    fi
+  fi
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
 
      if test $gl_cv_have_include_next = yes; then
@@ -20101,6 +21448,58 @@ 
 
 
 
+  if test "$gl_threads_api" = posix; then
+    # OSF/1 4.0 and Mac OS X 10.1 lack the pthread_rwlock_t type and the
+    # pthread_rwlock_* functions.
+    ac_fn_c_check_type "$LINENO" "pthread_rwlock_t" "ac_cv_type_pthread_rwlock_t" "#include <pthread.h>
+"
+if test "x$ac_cv_type_pthread_rwlock_t" = xyes; then :
+
+$as_echo "#define HAVE_PTHREAD_RWLOCK 1" >>confdefs.h
+
+fi
+
+    # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro.
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+      #include <pthread.h>
+int
+main ()
+{
+
+#if __FreeBSD__ == 4
+error "No, in FreeBSD 4.0 recursive mutexes actually don't work."
+#elif (defined __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ \
+       && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070)
+error "No, in Mac OS X < 10.7 recursive mutexes actually don't work."
+#else
+int x = (int)PTHREAD_MUTEX_RECURSIVE;
+return !x;
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+$as_echo "#define HAVE_PTHREAD_MUTEX_RECURSIVE 1" >>confdefs.h
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  fi
+  :
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define GNULIB_LOCK 1
+_ACEOF
+
+
+
+
 
   :
 
@@ -24775,6 +26174,8 @@ 
 
 
 
+
+
   if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for working strerror function" >&5
 $as_echo_n "checking for working strerror function... " >&6; }
@@ -24822,6 +26223,10 @@ 
         ;;
     esac
 
+                  case "$gl_cv_func_strerror_r_works" in
+        *no) REPLACE_STRERROR=1 ;;
+      esac
+
   else
             REPLACE_STRERROR=1
   fi
@@ -24912,6 +26317,92 @@ 
 
 
 
+
+      ac_fn_c_check_decl "$LINENO" "strerror_r" "ac_cv_have_decl_strerror_r" "$ac_includes_default"
+if test "x$ac_cv_have_decl_strerror_r" = xyes; then :
+  HAVE_DECL_STRERROR_R=1
+else
+  HAVE_DECL_STRERROR_R=0
+fi
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_STRERROR_R_ORIG $HAVE_DECL_STRERROR_R
+_ACEOF
+
+
+  if test $ac_cv_func_strerror_r = yes; then
+    if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
+      if test $gl_cv_func_strerror_r_posix_signature = yes; then
+        case "$gl_cv_func_strerror_r_works" in
+                    *no) REPLACE_STRERROR_R=1 ;;
+        esac
+      else
+                REPLACE_STRERROR_R=1
+      fi
+    else
+                  REPLACE_STRERROR_R=1
+    fi
+  fi
+
+  # Overwrite the findings of AC_FUNC_STRERROR_R (for code that uses that).
+
+
+  if test $HAVE_DECL_STRERROR_R = 0 || test $REPLACE_STRERROR_R = 1; then
+
+
+
+
+
+
+
+
+  gl_LIBOBJS="$gl_LIBOBJS strerror_r.$ac_objext"
+
+
+
+  :
+
+
+
+
+
+
+  :
+
+
+
+
+
+
+  :
+
+
+
+
+
+
+  fi
+
+
+
+
+
+          GNULIB_STRERROR_R=1
+
+
+
+
+
+$as_echo "#define GNULIB_TEST_STRERROR_R 1" >>confdefs.h
+
+
+
+
+
+
+
+
   if test $REPLACE_STRSTR = 0; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether strstr works in linear time" >&5
 $as_echo_n "checking whether strstr works in linear time... " >&6; }
@@ -25526,6 +27017,10 @@ 
 
 
 
+
+
+
+
   :
 
 
diff --git a/gnulib/import/Makefile.am b/gnulib/import/Makefile.am
index 9dca489..dd376ce 100644
--- a/gnulib/import/Makefile.am
+++ b/gnulib/import/Makefile.am
@@ -21,9 +21,9 @@ 
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
+# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strerror_r-posix strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
 
-AUTOMAKE_OPTIONS = 1.9.6 gnits
+AUTOMAKE_OPTIONS = 1.9.6 gnits subdir-objects
 
 SUBDIRS =
 noinst_HEADERS =
@@ -660,6 +660,13 @@ 
 
 ## end   gnulib module hard-locale
 
+## begin gnulib module havelib
+
+
+EXTRA_DIST += $(top_srcdir)/import/extra/config.rpath
+
+## end   gnulib module havelib
+
 ## begin gnulib module inet_ntop
 
 
@@ -841,6 +848,12 @@ 
 
 ## end   gnulib module localcharset
 
+## begin gnulib module lock
+
+libgnu_a_SOURCES += glthread/lock.h glthread/lock.c
+
+## end   gnulib module lock
+
 ## begin gnulib module lstat
 
 
@@ -1970,6 +1983,15 @@ 
 
 ## end   gnulib module strerror-override
 
+## begin gnulib module strerror_r-posix
+
+
+EXTRA_DIST += strerror_r.c
+
+EXTRA_libgnu_a_SOURCES += strerror_r.c
+
+## end   gnulib module strerror_r-posix
+
 ## begin gnulib module string
 
 BUILT_SOURCES += string.h
@@ -2301,6 +2323,14 @@ 
 
 ## end   gnulib module tempname
 
+## begin gnulib module threadlib
+
+libgnu_a_SOURCES += glthread/threadlib.c
+
+EXTRA_DIST += $(top_srcdir)/import/extra/config.rpath
+
+## end   gnulib module threadlib
+
 ## begin gnulib module time
 
 BUILT_SOURCES += time.h
diff --git a/gnulib/import/Makefile.in b/gnulib/import/Makefile.in
index dc8e80b..a977030 100644
--- a/gnulib/import/Makefile.in
+++ b/gnulib/import/Makefile.in
@@ -35,7 +35,7 @@ 
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
+# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strerror_r-posix strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
 
 
 
@@ -178,11 +178,15 @@ 
 	$(top_srcdir)/import/m4/isnand.m4 \
 	$(top_srcdir)/import/m4/isnanl.m4 \
 	$(top_srcdir)/import/m4/largefile.m4 \
+	$(top_srcdir)/import/m4/lib-ld.m4 \
+	$(top_srcdir)/import/m4/lib-link.m4 \
+	$(top_srcdir)/import/m4/lib-prefix.m4 \
 	$(top_srcdir)/import/m4/limits-h.m4 \
 	$(top_srcdir)/import/m4/localcharset.m4 \
 	$(top_srcdir)/import/m4/locale-fr.m4 \
 	$(top_srcdir)/import/m4/locale-ja.m4 \
 	$(top_srcdir)/import/m4/locale-zh.m4 \
+	$(top_srcdir)/import/m4/lock.m4 \
 	$(top_srcdir)/import/m4/longlong.m4 \
 	$(top_srcdir)/import/m4/lstat.m4 \
 	$(top_srcdir)/import/m4/malloc.m4 \
@@ -236,6 +240,7 @@ 
 	$(top_srcdir)/import/m4/strchrnul.m4 \
 	$(top_srcdir)/import/m4/strdup.m4 \
 	$(top_srcdir)/import/m4/strerror.m4 \
+	$(top_srcdir)/import/m4/strerror_r.m4 \
 	$(top_srcdir)/import/m4/string_h.m4 \
 	$(top_srcdir)/import/m4/strstr.m4 \
 	$(top_srcdir)/import/m4/strtok_r.m4 \
@@ -245,6 +250,7 @@ 
 	$(top_srcdir)/import/m4/sys_types_h.m4 \
 	$(top_srcdir)/import/m4/sys_uio_h.m4 \
 	$(top_srcdir)/import/m4/tempname.m4 \
+	$(top_srcdir)/import/m4/threadlib.m4 \
 	$(top_srcdir)/import/m4/time_h.m4 \
 	$(top_srcdir)/import/m4/unistd-safer.m4 \
 	$(top_srcdir)/import/m4/unistd_h.m4 \
@@ -268,15 +274,18 @@ 
 am__v_AR_1 = 
 libgnu_a_AR = $(AR) $(ARFLAGS)
 am__DEPENDENCIES_1 =
+am__dirstamp = $(am__leading_dot)dirstamp
 am_libgnu_a_OBJECTS = cloexec.$(OBJEXT) dirname-lgpl.$(OBJEXT) \
 	basename-lgpl.$(OBJEXT) stripslash.$(OBJEXT) \
 	exitfail.$(OBJEXT) fd-hook.$(OBJEXT) \
 	filenamecat-lgpl.$(OBJEXT) getprogname.$(OBJEXT) \
-	hard-locale.$(OBJEXT) localcharset.$(OBJEXT) malloca.$(OBJEXT) \
-	math.$(OBJEXT) openat-die.$(OBJEXT) save-cwd.$(OBJEXT) \
-	strnlen1.$(OBJEXT) sys_socket.$(OBJEXT) tempname.$(OBJEXT) \
-	unistd.$(OBJEXT) dup-safer.$(OBJEXT) fd-safer.$(OBJEXT) \
-	pipe-safer.$(OBJEXT) wctype-h.$(OBJEXT)
+	hard-locale.$(OBJEXT) localcharset.$(OBJEXT) \
+	glthread/lock.$(OBJEXT) malloca.$(OBJEXT) math.$(OBJEXT) \
+	openat-die.$(OBJEXT) save-cwd.$(OBJEXT) strnlen1.$(OBJEXT) \
+	sys_socket.$(OBJEXT) tempname.$(OBJEXT) \
+	glthread/threadlib.$(OBJEXT) unistd.$(OBJEXT) \
+	dup-safer.$(OBJEXT) fd-safer.$(OBJEXT) pipe-safer.$(OBJEXT) \
+	wctype-h.$(OBJEXT)
 libgnu_a_OBJECTS = $(am_libgnu_a_OBJECTS)
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 AM_V_P = $(am__v_P_@AM_V@)
@@ -1132,8 +1141,12 @@ 
 LIBGNU_LIBDEPS = @LIBGNU_LIBDEPS@
 LIBGNU_LTLIBDEPS = @LIBGNU_LTLIBDEPS@
 LIBINTL = @LIBINTL@
+LIBMULTITHREAD = @LIBMULTITHREAD@
 LIBOBJS = @LIBOBJS@
+LIBPTH = @LIBPTH@
+LIBPTH_PREFIX = @LIBPTH_PREFIX@
 LIBS = @LIBS@
+LIBTHREAD = @LIBTHREAD@
 LIMITS_H = @LIMITS_H@
 LN_S = @LN_S@
 LOCALCHARSET_TESTS_ENVIRONMENT = @LOCALCHARSET_TESTS_ENVIRONMENT@
@@ -1142,7 +1155,10 @@ 
 LOCALE_JA = @LOCALE_JA@
 LOCALE_ZH_CN = @LOCALE_ZH_CN@
 LTLIBINTL = @LTLIBINTL@
+LTLIBMULTITHREAD = @LTLIBMULTITHREAD@
 LTLIBOBJS = @LTLIBOBJS@
+LTLIBPTH = @LTLIBPTH@
+LTLIBTHREAD = @LTLIBTHREAD@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
 MKDIR_P = @MKDIR_P@
@@ -1499,7 +1515,7 @@ 
 top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
-AUTOMAKE_OPTIONS = 1.9.6 gnits
+AUTOMAKE_OPTIONS = 1.9.6 gnits subdir-objects
 SUBDIRS = 
 noinst_HEADERS = 
 noinst_LIBRARIES = libgnu.a
@@ -1514,31 +1530,33 @@ 
 	fnmatch_loop.c fpucw.h frexp.c frexp.c frexpl.c fstat.c \
 	at-func.c fstatat.c getcwd.c getcwd-lgpl.c getdtablesize.c \
 	getlogin_r.c gettimeofday.c glob-libc.h glob.c glob.in.h \
-	hard-locale.h inet_ntop.c intprops.h inttypes.in.h float+.h \
-	isnan.c isnand-nolibm.h isnand.c float+.h isnan.c \
-	isnanl-nolibm.h isnanl.c limits.in.h config.charset \
-	ref-add.sin ref-del.sin lstat.c malloc.c malloca.h \
-	malloca.valgrind math.in.h mbrtowc.c mbsinit.c \
-	mbsrtowcs-impl.h mbsrtowcs-state.c mbsrtowcs.c memchr.c \
-	memchr.valgrind memmem.c str-two-way.h mempcpy.c memrchr.c \
-	mkdir.c mkdtemp.c mkostemp.c msvc-inval.c msvc-inval.h \
-	msvc-nothrow.c msvc-nothrow.h netinet_in.in.h open.c openat.c \
-	openat.h dirent-private.h opendir.c pathmax.h rawmemchr.c \
-	rawmemchr.valgrind dirent-private.h readdir.c readlink.c \
-	realloc.c rename.c dirent-private.h rewinddir.c rmdir.c \
-	same-inode.h save-cwd.h secure_getenv.c setenv.c signal.in.h \
-	$(top_srcdir)/import/extra/snippet/_Noreturn.h \
+	hard-locale.h $(top_srcdir)/import/extra/config.rpath \
+	inet_ntop.c intprops.h inttypes.in.h float+.h isnan.c \
+	isnand-nolibm.h isnand.c float+.h isnan.c isnanl-nolibm.h \
+	isnanl.c limits.in.h config.charset ref-add.sin ref-del.sin \
+	lstat.c malloc.c malloca.h malloca.valgrind math.in.h \
+	mbrtowc.c mbsinit.c mbsrtowcs-impl.h mbsrtowcs-state.c \
+	mbsrtowcs.c memchr.c memchr.valgrind memmem.c str-two-way.h \
+	mempcpy.c memrchr.c mkdir.c mkdtemp.c mkostemp.c msvc-inval.c \
+	msvc-inval.h msvc-nothrow.c msvc-nothrow.h netinet_in.in.h \
+	open.c openat.c openat.h dirent-private.h opendir.c pathmax.h \
+	rawmemchr.c rawmemchr.valgrind dirent-private.h readdir.c \
+	readlink.c realloc.c rename.c dirent-private.h rewinddir.c \
+	rmdir.c same-inode.h save-cwd.h secure_getenv.c setenv.c \
+	signal.in.h $(top_srcdir)/import/extra/snippet/_Noreturn.h \
 	$(top_srcdir)/import/extra/snippet/arg-nonnull.h \
 	$(top_srcdir)/import/extra/snippet/c++defs.h \
 	$(top_srcdir)/import/extra/snippet/warn-on-use.h stat.c \
 	stdalign.in.h stdbool.in.h stddef.in.h stdint.in.h stdio.in.h \
 	stdlib.in.h strchrnul.c strchrnul.valgrind strdup.c streq.h \
-	strerror.c strerror-override.c strerror-override.h string.in.h \
-	str-two-way.h strstr.c strtok_r.c sys_socket.in.h \
-	sys_stat.in.h sys_time.in.h sys_types.in.h sys_uio.in.h \
-	tempname.h time.in.h unistd.in.h unistd--.h unistd-safer.h \
-	unsetenv.c $(top_srcdir)/import/extra/update-copyright \
-	verify.h wchar.in.h wctype.in.h
+	strerror.c strerror-override.c strerror-override.h \
+	strerror_r.c string.in.h str-two-way.h strstr.c strtok_r.c \
+	sys_socket.in.h sys_stat.in.h sys_time.in.h sys_types.in.h \
+	sys_uio.in.h tempname.h \
+	$(top_srcdir)/import/extra/config.rpath time.in.h unistd.in.h \
+	unistd--.h unistd-safer.h unsetenv.c \
+	$(top_srcdir)/import/extra/update-copyright verify.h \
+	wchar.in.h wctype.in.h
 
 # The BUILT_SOURCES created by this Makefile snippet are not used via #include
 # statements but through direct file reference. Therefore this snippet must be
@@ -1580,9 +1598,10 @@ 
 libgnu_a_SOURCES = cloexec.c dirname-lgpl.c basename-lgpl.c \
 	stripslash.c exitfail.c fd-hook.c filenamecat-lgpl.c \
 	getprogname.h getprogname.c gettext.h hard-locale.c \
-	localcharset.h localcharset.c malloca.c math.c openat-die.c \
-	save-cwd.c strnlen1.h strnlen1.c sys_socket.c tempname.c \
-	unistd.c dup-safer.c fd-safer.c pipe-safer.c wctype-h.c
+	localcharset.h localcharset.c glthread/lock.h glthread/lock.c \
+	malloca.c math.c openat-die.c save-cwd.c strnlen1.h strnlen1.c \
+	sys_socket.c tempname.c glthread/threadlib.c unistd.c \
+	dup-safer.c fd-safer.c pipe-safer.c wctype-h.c
 libgnu_a_LIBADD = $(gl_LIBOBJS) @ALLOCA@
 libgnu_a_DEPENDENCIES = $(gl_LIBOBJS) @ALLOCA@
 EXTRA_libgnu_a_SOURCES = alloca.c openat-proc.c canonicalize-lgpl.c \
@@ -1597,7 +1616,8 @@ 
 	msvc-nothrow.c open.c openat.c opendir.c rawmemchr.c readdir.c \
 	readlink.c realloc.c rename.c rewinddir.c rmdir.c \
 	secure_getenv.c setenv.c stat.c strchrnul.c strdup.c \
-	strerror.c strerror-override.c strstr.c strtok_r.c unsetenv.c
+	strerror.c strerror-override.c strerror_r.c strstr.c \
+	strtok_r.c unsetenv.c
 
 # Use this preprocessor expression to decide whether #include_next works.
 # Do not rely on a 'configure'-time test for this, since the expression
@@ -1650,6 +1670,16 @@ 
 
 clean-noinstLIBRARIES:
 	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)
+glthread/$(am__dirstamp):
+	@$(MKDIR_P) glthread
+	@: > glthread/$(am__dirstamp)
+glthread/$(DEPDIR)/$(am__dirstamp):
+	@$(MKDIR_P) glthread/$(DEPDIR)
+	@: > glthread/$(DEPDIR)/$(am__dirstamp)
+glthread/lock.$(OBJEXT): glthread/$(am__dirstamp) \
+	glthread/$(DEPDIR)/$(am__dirstamp)
+glthread/threadlib.$(OBJEXT): glthread/$(am__dirstamp) \
+	glthread/$(DEPDIR)/$(am__dirstamp)
 
 libgnu.a: $(libgnu_a_OBJECTS) $(libgnu_a_DEPENDENCIES) $(EXTRA_libgnu_a_DEPENDENCIES) 
 	$(AM_V_at)-rm -f libgnu.a
@@ -1669,6 +1699,7 @@ 
 
 mostlyclean-compile:
 	-rm -f *.$(OBJEXT)
+	-rm -f glthread/*.$(OBJEXT)
 
 distclean-compile:
 	-rm -f *.tab.c
@@ -1753,6 +1784,7 @@ 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strdup.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strerror-override.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strerror.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strerror_r.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stripslash.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strnlen1.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strstr.Po@am__quote@
@@ -1762,17 +1794,21 @@ 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/unistd.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/unsetenv.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/wctype-h.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@glthread/$(DEPDIR)/lock.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@glthread/$(DEPDIR)/threadlib.Po@am__quote@
 
 .c.o:
-@am__fastdepCC_TRUE@	$(AM_V_CC)$(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
-@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@am__fastdepCC_TRUE@	$(AM_V_CC)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`;\
+@am__fastdepCC_TRUE@	$(COMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
+@am__fastdepCC_TRUE@	$(am__mv) $$depbase.Tpo $$depbase.Po
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(COMPILE) -c -o $@ $<
 
 .c.obj:
-@am__fastdepCC_TRUE@	$(AM_V_CC)$(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ `$(CYGPATH_W) '$<'`
-@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@am__fastdepCC_TRUE@	$(AM_V_CC)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.obj$$||'`;\
+@am__fastdepCC_TRUE@	$(COMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ `$(CYGPATH_W) '$<'` &&\
+@am__fastdepCC_TRUE@	$(am__mv) $$depbase.Tpo $$depbase.Po
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(COMPILE) -c -o $@ `$(CYGPATH_W) '$<'`
@@ -1966,6 +2002,8 @@ 
 distclean-generic:
 	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
 	-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
+	-rm -f glthread/$(DEPDIR)/$(am__dirstamp)
+	-rm -f glthread/$(am__dirstamp)
 	-test -z "$(DISTCLEANFILES)" || rm -f $(DISTCLEANFILES)
 
 maintainer-clean-generic:
@@ -1979,7 +2017,7 @@ 
 	mostlyclean-am
 
 distclean: distclean-recursive
-	-rm -rf ./$(DEPDIR)
+	-rm -rf ./$(DEPDIR) glthread/$(DEPDIR)
 	-rm -f Makefile
 distclean-am: clean-am distclean-compile distclean-generic \
 	distclean-tags
@@ -2025,7 +2063,7 @@ 
 installcheck-am:
 
 maintainer-clean: maintainer-clean-recursive
-	-rm -rf ./$(DEPDIR)
+	-rm -rf ./$(DEPDIR) glthread/$(DEPDIR)
 	-rm -f Makefile
 maintainer-clean-am: distclean-am maintainer-clean-generic
 
diff --git a/gnulib/import/extra/config.rpath b/gnulib/import/extra/config.rpath
new file mode 100755
index 0000000..98183ff
--- /dev/null
+++ b/gnulib/import/extra/config.rpath
@@ -0,0 +1,684 @@ 
+#! /bin/sh
+# Output a system dependent set of variables, describing how to set the
+# run time search path of shared libraries in an executable.
+#
+#   Copyright 1996-2016 Free Software Foundation, Inc.
+#   Taken from GNU libtool, 2001
+#   Originally by Gordon Matzigkeit <gord@gnu.ai.mit.edu>, 1996
+#
+#   This file is free software; the Free Software Foundation gives
+#   unlimited permission to copy and/or distribute it, with or without
+#   modifications, as long as this notice is preserved.
+#
+# The first argument passed to this file is the canonical host specification,
+#    CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM
+# or
+#    CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
+# The environment variables CC, GCC, LDFLAGS, LD, with_gnu_ld
+# should be set by the caller.
+#
+# The set of defined variables is at the end of this script.
+
+# Known limitations:
+# - On IRIX 6.5 with CC="cc", the run time search patch must not be longer
+#   than 256 bytes, otherwise the compiler driver will dump core. The only
+#   known workaround is to choose shorter directory names for the build
+#   directory and/or the installation directory.
+
+# All known linkers require a '.a' archive for static linking (except MSVC,
+# which needs '.lib').
+libext=a
+shrext=.so
+
+host="$1"
+host_cpu=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\1/'`
+host_vendor=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\2/'`
+host_os=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
+
+# Code taken from libtool.m4's _LT_CC_BASENAME.
+
+for cc_temp in $CC""; do
+  case $cc_temp in
+    compile | *[\\/]compile | ccache | *[\\/]ccache ) ;;
+    distcc | *[\\/]distcc | purify | *[\\/]purify ) ;;
+    \-*) ;;
+    *) break;;
+  esac
+done
+cc_basename=`echo "$cc_temp" | sed -e 's%^.*/%%'`
+
+# Code taken from libtool.m4's _LT_COMPILER_PIC.
+
+wl=
+if test "$GCC" = yes; then
+  wl='-Wl,'
+else
+  case "$host_os" in
+    aix*)
+      wl='-Wl,'
+      ;;
+    mingw* | cygwin* | pw32* | os2* | cegcc*)
+      ;;
+    hpux9* | hpux10* | hpux11*)
+      wl='-Wl,'
+      ;;
+    irix5* | irix6* | nonstopux*)
+      wl='-Wl,'
+      ;;
+    linux* | k*bsd*-gnu | kopensolaris*-gnu)
+      case $cc_basename in
+        ecc*)
+          wl='-Wl,'
+          ;;
+        icc* | ifort*)
+          wl='-Wl,'
+          ;;
+        lf95*)
+          wl='-Wl,'
+          ;;
+        nagfor*)
+          wl='-Wl,-Wl,,'
+          ;;
+        pgcc* | pgf77* | pgf90* | pgf95* | pgfortran*)
+          wl='-Wl,'
+          ;;
+        ccc*)
+          wl='-Wl,'
+          ;;
+        xl* | bgxl* | bgf* | mpixl*)
+          wl='-Wl,'
+          ;;
+        como)
+          wl='-lopt='
+          ;;
+        *)
+          case `$CC -V 2>&1 | sed 5q` in
+            *Sun\ F* | *Sun*Fortran*)
+              wl=
+              ;;
+            *Sun\ C*)
+              wl='-Wl,'
+              ;;
+          esac
+          ;;
+      esac
+      ;;
+    newsos6)
+      ;;
+    *nto* | *qnx*)
+      ;;
+    osf3* | osf4* | osf5*)
+      wl='-Wl,'
+      ;;
+    rdos*)
+      ;;
+    solaris*)
+      case $cc_basename in
+        f77* | f90* | f95* | sunf77* | sunf90* | sunf95*)
+          wl='-Qoption ld '
+          ;;
+        *)
+          wl='-Wl,'
+          ;;
+      esac
+      ;;
+    sunos4*)
+      wl='-Qoption ld '
+      ;;
+    sysv4 | sysv4.2uw2* | sysv4.3*)
+      wl='-Wl,'
+      ;;
+    sysv4*MP*)
+      ;;
+    sysv5* | unixware* | sco3.2v5* | sco5v6* | OpenUNIX*)
+      wl='-Wl,'
+      ;;
+    unicos*)
+      wl='-Wl,'
+      ;;
+    uts4*)
+      ;;
+  esac
+fi
+
+# Code taken from libtool.m4's _LT_LINKER_SHLIBS.
+
+hardcode_libdir_flag_spec=
+hardcode_libdir_separator=
+hardcode_direct=no
+hardcode_minus_L=no
+
+case "$host_os" in
+  cygwin* | mingw* | pw32* | cegcc*)
+    # FIXME: the MSVC++ port hasn't been tested in a loooong time
+    # When not using gcc, we currently assume that we are using
+    # Microsoft Visual C++.
+    if test "$GCC" != yes; then
+      with_gnu_ld=no
+    fi
+    ;;
+  interix*)
+    # we just hope/assume this is gcc and not c89 (= MSVC++)
+    with_gnu_ld=yes
+    ;;
+  openbsd*)
+    with_gnu_ld=no
+    ;;
+esac
+
+ld_shlibs=yes
+if test "$with_gnu_ld" = yes; then
+  # Set some defaults for GNU ld with shared library support. These
+  # are reset later if shared libraries are not supported. Putting them
+  # here allows them to be overridden if necessary.
+  # Unlike libtool, we use -rpath here, not --rpath, since the documented
+  # option of GNU ld is called -rpath, not --rpath.
+  hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+  case "$host_os" in
+    aix[3-9]*)
+      # On AIX/PPC, the GNU linker is very broken
+      if test "$host_cpu" != ia64; then
+        ld_shlibs=no
+      fi
+      ;;
+    amigaos*)
+      case "$host_cpu" in
+        powerpc)
+          ;;
+        m68k)
+          hardcode_libdir_flag_spec='-L$libdir'
+          hardcode_minus_L=yes
+          ;;
+      esac
+      ;;
+    beos*)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    cygwin* | mingw* | pw32* | cegcc*)
+      # hardcode_libdir_flag_spec is actually meaningless, as there is
+      # no search path for DLLs.
+      hardcode_libdir_flag_spec='-L$libdir'
+      if $LD --help 2>&1 | grep 'auto-import' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    haiku*)
+      ;;
+    interix[3-9]*)
+      hardcode_direct=no
+      hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+      ;;
+    gnu* | linux* | tpf* | k*bsd*-gnu | kopensolaris*-gnu)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    netbsd*)
+      ;;
+    solaris*)
+      if $LD -v 2>&1 | grep 'BFD 2\.8' > /dev/null; then
+        ld_shlibs=no
+      elif $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX*)
+      case `$LD -v 2>&1` in
+        *\ [01].* | *\ 2.[0-9].* | *\ 2.1[0-5].*)
+          ld_shlibs=no
+          ;;
+        *)
+          if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+            hardcode_libdir_flag_spec='`test -z "$SCOABSPATH" && echo ${wl}-rpath,$libdir`'
+          else
+            ld_shlibs=no
+          fi
+          ;;
+      esac
+      ;;
+    sunos4*)
+      hardcode_direct=yes
+      ;;
+    *)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+  esac
+  if test "$ld_shlibs" = no; then
+    hardcode_libdir_flag_spec=
+  fi
+else
+  case "$host_os" in
+    aix3*)
+      # Note: this linker hardcodes the directories in LIBPATH if there
+      # are no directories specified by -L.
+      hardcode_minus_L=yes
+      if test "$GCC" = yes; then
+        # Neither direct hardcoding nor static linking is supported with a
+        # broken collect2.
+        hardcode_direct=unsupported
+      fi
+      ;;
+    aix[4-9]*)
+      if test "$host_cpu" = ia64; then
+        # On IA64, the linker does run time linking by default, so we don't
+        # have to do anything special.
+        aix_use_runtimelinking=no
+      else
+        aix_use_runtimelinking=no
+        # Test if we are trying to use run time linking or normal
+        # AIX style linking. If -brtl is somewhere in LDFLAGS, we
+        # need to do runtime linking.
+        case $host_os in aix4.[23]|aix4.[23].*|aix[5-9]*)
+          for ld_flag in $LDFLAGS; do
+            if (test $ld_flag = "-brtl" || test $ld_flag = "-Wl,-brtl"); then
+              aix_use_runtimelinking=yes
+              break
+            fi
+          done
+          ;;
+        esac
+      fi
+      hardcode_direct=yes
+      hardcode_libdir_separator=':'
+      if test "$GCC" = yes; then
+        case $host_os in aix4.[012]|aix4.[012].*)
+          collect2name=`${CC} -print-prog-name=collect2`
+          if test -f "$collect2name" && \
+            strings "$collect2name" | grep resolve_lib_name >/dev/null
+          then
+            # We have reworked collect2
+            :
+          else
+            # We have old collect2
+            hardcode_direct=unsupported
+            hardcode_minus_L=yes
+            hardcode_libdir_flag_spec='-L$libdir'
+            hardcode_libdir_separator=
+          fi
+          ;;
+        esac
+      fi
+      # Begin _LT_AC_SYS_LIBPATH_AIX.
+      echo 'int main () { return 0; }' > conftest.c
+      ${CC} ${LDFLAGS} conftest.c -o conftest
+      aix_libpath=`dump -H conftest 2>/dev/null | sed -n -e '/Import File Strings/,/^$/ { /^0/ { s/^0  *\(.*\)$/\1/; p; }
+}'`
+      if test -z "$aix_libpath"; then
+        aix_libpath=`dump -HX64 conftest 2>/dev/null | sed -n -e '/Import File Strings/,/^$/ { /^0/ { s/^0  *\(.*\)$/\1/; p; }
+}'`
+      fi
+      if test -z "$aix_libpath"; then
+        aix_libpath="/usr/lib:/lib"
+      fi
+      rm -f conftest.c conftest
+      # End _LT_AC_SYS_LIBPATH_AIX.
+      if test "$aix_use_runtimelinking" = yes; then
+        hardcode_libdir_flag_spec='${wl}-blibpath:$libdir:'"$aix_libpath"
+      else
+        if test "$host_cpu" = ia64; then
+          hardcode_libdir_flag_spec='${wl}-R $libdir:/usr/lib:/lib'
+        else
+          hardcode_libdir_flag_spec='${wl}-blibpath:$libdir:'"$aix_libpath"
+        fi
+      fi
+      ;;
+    amigaos*)
+      case "$host_cpu" in
+        powerpc)
+          ;;
+        m68k)
+          hardcode_libdir_flag_spec='-L$libdir'
+          hardcode_minus_L=yes
+          ;;
+      esac
+      ;;
+    bsdi[45]*)
+      ;;
+    cygwin* | mingw* | pw32* | cegcc*)
+      # When not using gcc, we currently assume that we are using
+      # Microsoft Visual C++.
+      # hardcode_libdir_flag_spec is actually meaningless, as there is
+      # no search path for DLLs.
+      hardcode_libdir_flag_spec=' '
+      libext=lib
+      ;;
+    darwin* | rhapsody*)
+      hardcode_direct=no
+      if { case $cc_basename in ifort*) true;; *) test "$GCC" = yes;; esac; }; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    dgux*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      ;;
+    freebsd2.[01]*)
+      hardcode_direct=yes
+      hardcode_minus_L=yes
+      ;;
+    freebsd* | dragonfly*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      hardcode_direct=yes
+      ;;
+    hpux9*)
+      hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+      hardcode_libdir_separator=:
+      hardcode_direct=yes
+      # hardcode_minus_L: Not really in the search PATH,
+      # but as the default location of the library.
+      hardcode_minus_L=yes
+      ;;
+    hpux10*)
+      if test "$with_gnu_ld" = no; then
+        hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+        hardcode_libdir_separator=:
+        hardcode_direct=yes
+        # hardcode_minus_L: Not really in the search PATH,
+        # but as the default location of the library.
+        hardcode_minus_L=yes
+      fi
+      ;;
+    hpux11*)
+      if test "$with_gnu_ld" = no; then
+        hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+        hardcode_libdir_separator=:
+        case $host_cpu in
+          hppa*64*|ia64*)
+            hardcode_direct=no
+            ;;
+          *)
+            hardcode_direct=yes
+            # hardcode_minus_L: Not really in the search PATH,
+            # but as the default location of the library.
+            hardcode_minus_L=yes
+            ;;
+        esac
+      fi
+      ;;
+    irix5* | irix6* | nonstopux*)
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    netbsd*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      hardcode_direct=yes
+      ;;
+    newsos6)
+      hardcode_direct=yes
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    *nto* | *qnx*)
+      ;;
+    openbsd*)
+      if test -f /usr/libexec/ld.so; then
+        hardcode_direct=yes
+        if test -z "`echo __ELF__ | $CC -E - | grep __ELF__`" || test "$host_os-$host_cpu" = "openbsd2.8-powerpc"; then
+          hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+        else
+          case "$host_os" in
+            openbsd[01].* | openbsd2.[0-7] | openbsd2.[0-7].*)
+              hardcode_libdir_flag_spec='-R$libdir'
+              ;;
+            *)
+              hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+              ;;
+          esac
+        fi
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    os2*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      hardcode_minus_L=yes
+      ;;
+    osf3*)
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    osf4* | osf5*)
+      if test "$GCC" = yes; then
+        hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      else
+        # Both cc and cxx compiler support -rpath directly
+        hardcode_libdir_flag_spec='-rpath $libdir'
+      fi
+      hardcode_libdir_separator=:
+      ;;
+    solaris*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      ;;
+    sunos4*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      hardcode_direct=yes
+      hardcode_minus_L=yes
+      ;;
+    sysv4)
+      case $host_vendor in
+        sni)
+          hardcode_direct=yes # is this really true???
+          ;;
+        siemens)
+          hardcode_direct=no
+          ;;
+        motorola)
+          hardcode_direct=no #Motorola manual says yes, but my tests say they lie
+          ;;
+      esac
+      ;;
+    sysv4.3*)
+      ;;
+    sysv4*MP*)
+      if test -d /usr/nec; then
+        ld_shlibs=yes
+      fi
+      ;;
+    sysv4*uw2* | sysv5OpenUNIX* | sysv5UnixWare7.[01].[10]* | unixware7* | sco3.2v5.0.[024]*)
+      ;;
+    sysv5* | sco3.2v5* | sco5v6*)
+      hardcode_libdir_flag_spec='`test -z "$SCOABSPATH" && echo ${wl}-R,$libdir`'
+      hardcode_libdir_separator=':'
+      ;;
+    uts4*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      ;;
+    *)
+      ld_shlibs=no
+      ;;
+  esac
+fi
+
+# Check dynamic linker characteristics
+# Code taken from libtool.m4's _LT_SYS_DYNAMIC_LINKER.
+# Unlike libtool.m4, here we don't care about _all_ names of the library, but
+# only about the one the linker finds when passed -lNAME. This is the last
+# element of library_names_spec in libtool.m4, or possibly two of them if the
+# linker has special search rules.
+library_names_spec=      # the last element of library_names_spec in libtool.m4
+libname_spec='lib$name'
+case "$host_os" in
+  aix3*)
+    library_names_spec='$libname.a'
+    ;;
+  aix[4-9]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  amigaos*)
+    case "$host_cpu" in
+      powerpc*)
+        library_names_spec='$libname$shrext' ;;
+      m68k)
+        library_names_spec='$libname.a' ;;
+    esac
+    ;;
+  beos*)
+    library_names_spec='$libname$shrext'
+    ;;
+  bsdi[45]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  cygwin* | mingw* | pw32* | cegcc*)
+    shrext=.dll
+    library_names_spec='$libname.dll.a $libname.lib'
+    ;;
+  darwin* | rhapsody*)
+    shrext=.dylib
+    library_names_spec='$libname$shrext'
+    ;;
+  dgux*)
+    library_names_spec='$libname$shrext'
+    ;;
+  freebsd[23].*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  freebsd* | dragonfly*)
+    library_names_spec='$libname$shrext'
+    ;;
+  gnu*)
+    library_names_spec='$libname$shrext'
+    ;;
+  haiku*)
+    library_names_spec='$libname$shrext'
+    ;;
+  hpux9* | hpux10* | hpux11*)
+    case $host_cpu in
+      ia64*)
+        shrext=.so
+        ;;
+      hppa*64*)
+        shrext=.sl
+        ;;
+      *)
+        shrext=.sl
+        ;;
+    esac
+    library_names_spec='$libname$shrext'
+    ;;
+  interix[3-9]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  irix5* | irix6* | nonstopux*)
+    library_names_spec='$libname$shrext'
+    case "$host_os" in
+      irix5* | nonstopux*)
+        libsuff= shlibsuff=
+        ;;
+      *)
+        case $LD in
+          *-32|*"-32 "|*-melf32bsmip|*"-melf32bsmip ") libsuff= shlibsuff= ;;
+          *-n32|*"-n32 "|*-melf32bmipn32|*"-melf32bmipn32 ") libsuff=32 shlibsuff=N32 ;;
+          *-64|*"-64 "|*-melf64bmip|*"-melf64bmip ") libsuff=64 shlibsuff=64 ;;
+          *) libsuff= shlibsuff= ;;
+        esac
+        ;;
+    esac
+    ;;
+  linux*oldld* | linux*aout* | linux*coff*)
+    ;;
+  linux* | k*bsd*-gnu | kopensolaris*-gnu)
+    library_names_spec='$libname$shrext'
+    ;;
+  knetbsd*-gnu)
+    library_names_spec='$libname$shrext'
+    ;;
+  netbsd*)
+    library_names_spec='$libname$shrext'
+    ;;
+  newsos6)
+    library_names_spec='$libname$shrext'
+    ;;
+  *nto* | *qnx*)
+    library_names_spec='$libname$shrext'
+    ;;
+  openbsd*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  os2*)
+    libname_spec='$name'
+    shrext=.dll
+    library_names_spec='$libname.a'
+    ;;
+  osf3* | osf4* | osf5*)
+    library_names_spec='$libname$shrext'
+    ;;
+  rdos*)
+    ;;
+  solaris*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sunos4*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  sysv4 | sysv4.3*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sysv4*MP*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX* | sysv4*uw2*)
+    library_names_spec='$libname$shrext'
+    ;;
+  tpf*)
+    library_names_spec='$libname$shrext'
+    ;;
+  uts4*)
+    library_names_spec='$libname$shrext'
+    ;;
+esac
+
+sed_quote_subst='s/\(["`$\\]\)/\\\1/g'
+escaped_wl=`echo "X$wl" | sed -e 's/^X//' -e "$sed_quote_subst"`
+shlibext=`echo "$shrext" | sed -e 's,^\.,,'`
+escaped_libname_spec=`echo "X$libname_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+escaped_library_names_spec=`echo "X$library_names_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+escaped_hardcode_libdir_flag_spec=`echo "X$hardcode_libdir_flag_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+
+LC_ALL=C sed -e 's/^\([a-zA-Z0-9_]*\)=/acl_cv_\1=/' <<EOF
+
+# How to pass a linker flag through the compiler.
+wl="$escaped_wl"
+
+# Static library suffix (normally "a").
+libext="$libext"
+
+# Shared library suffix (normally "so").
+shlibext="$shlibext"
+
+# Format of library name prefix.
+libname_spec="$escaped_libname_spec"
+
+# Library names that the linker finds when passed -lNAME.
+library_names_spec="$escaped_library_names_spec"
+
+# Flag to hardcode \$libdir into a binary during linking.
+# This must work even if \$libdir does not exist.
+hardcode_libdir_flag_spec="$escaped_hardcode_libdir_flag_spec"
+
+# Whether we need a single -rpath flag with a separated argument.
+hardcode_libdir_separator="$hardcode_libdir_separator"
+
+# Set to yes if using DIR/libNAME.so during linking hardcodes DIR into the
+# resulting binary.
+hardcode_direct="$hardcode_direct"
+
+# Set to yes if using the -LDIR flag during linking hardcodes DIR into the
+# resulting binary.
+hardcode_minus_L="$hardcode_minus_L"
+
+EOF
diff --git a/gnulib/import/glthread/lock.c b/gnulib/import/glthread/lock.c
new file mode 100644
index 0000000..935043b
--- /dev/null
+++ b/gnulib/import/glthread/lock.c
@@ -0,0 +1,1057 @@ 
+/* Locking in multithreaded situations.
+   Copyright (C) 2005-2016 Free Software Foundation, Inc.
+
+   This program 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, or (at your option)
+   any later version.
+
+   This program 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 program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005.
+   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
+   gthr-win32.h.  */
+
+#include <config.h>
+
+#include "glthread/lock.h"
+
+/* ========================================================================= */
+
+#if USE_POSIX_THREADS
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+# if HAVE_PTHREAD_RWLOCK
+
+#  if !defined PTHREAD_RWLOCK_INITIALIZER
+
+int
+glthread_rwlock_init_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_rwlock_init (&lock->rwlock, NULL);
+  if (err != 0)
+    return err;
+  lock->initialized = 1;
+  return 0;
+}
+
+int
+glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock)
+{
+  if (!lock->initialized)
+    {
+      int err;
+
+      err = pthread_mutex_lock (&lock->guard);
+      if (err != 0)
+        return err;
+      if (!lock->initialized)
+        {
+          err = glthread_rwlock_init_multithreaded (lock);
+          if (err != 0)
+            {
+              pthread_mutex_unlock (&lock->guard);
+              return err;
+            }
+        }
+      err = pthread_mutex_unlock (&lock->guard);
+      if (err != 0)
+        return err;
+    }
+  return pthread_rwlock_rdlock (&lock->rwlock);
+}
+
+int
+glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock)
+{
+  if (!lock->initialized)
+    {
+      int err;
+
+      err = pthread_mutex_lock (&lock->guard);
+      if (err != 0)
+        return err;
+      if (!lock->initialized)
+        {
+          err = glthread_rwlock_init_multithreaded (lock);
+          if (err != 0)
+            {
+              pthread_mutex_unlock (&lock->guard);
+              return err;
+            }
+        }
+      err = pthread_mutex_unlock (&lock->guard);
+      if (err != 0)
+        return err;
+    }
+  return pthread_rwlock_wrlock (&lock->rwlock);
+}
+
+int
+glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock)
+{
+  if (!lock->initialized)
+    return EINVAL;
+  return pthread_rwlock_unlock (&lock->rwlock);
+}
+
+int
+glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  if (!lock->initialized)
+    return EINVAL;
+  err = pthread_rwlock_destroy (&lock->rwlock);
+  if (err != 0)
+    return err;
+  lock->initialized = 0;
+  return 0;
+}
+
+#  endif
+
+# else
+
+int
+glthread_rwlock_init_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_init (&lock->lock, NULL);
+  if (err != 0)
+    return err;
+  err = pthread_cond_init (&lock->waiting_readers, NULL);
+  if (err != 0)
+    return err;
+  err = pthread_cond_init (&lock->waiting_writers, NULL);
+  if (err != 0)
+    return err;
+  lock->waiting_writers_count = 0;
+  lock->runcount = 0;
+  return 0;
+}
+
+int
+glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_lock (&lock->lock);
+  if (err != 0)
+    return err;
+  /* Test whether only readers are currently running, and whether the runcount
+     field will not overflow.  */
+  /* POSIX says: "It is implementation-defined whether the calling thread
+     acquires the lock when a writer does not hold the lock and there are
+     writers blocked on the lock."  Let's say, no: give the writers a higher
+     priority.  */
+  while (!(lock->runcount + 1 > 0 && lock->waiting_writers_count == 0))
+    {
+      /* This thread has to wait for a while.  Enqueue it among the
+         waiting_readers.  */
+      err = pthread_cond_wait (&lock->waiting_readers, &lock->lock);
+      if (err != 0)
+        {
+          pthread_mutex_unlock (&lock->lock);
+          return err;
+        }
+    }
+  lock->runcount++;
+  return pthread_mutex_unlock (&lock->lock);
+}
+
+int
+glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_lock (&lock->lock);
+  if (err != 0)
+    return err;
+  /* Test whether no readers or writers are currently running.  */
+  while (!(lock->runcount == 0))
+    {
+      /* This thread has to wait for a while.  Enqueue it among the
+         waiting_writers.  */
+      lock->waiting_writers_count++;
+      err = pthread_cond_wait (&lock->waiting_writers, &lock->lock);
+      if (err != 0)
+        {
+          lock->waiting_writers_count--;
+          pthread_mutex_unlock (&lock->lock);
+          return err;
+        }
+      lock->waiting_writers_count--;
+    }
+  lock->runcount--; /* runcount becomes -1 */
+  return pthread_mutex_unlock (&lock->lock);
+}
+
+int
+glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_lock (&lock->lock);
+  if (err != 0)
+    return err;
+  if (lock->runcount < 0)
+    {
+      /* Drop a writer lock.  */
+      if (!(lock->runcount == -1))
+        {
+          pthread_mutex_unlock (&lock->lock);
+          return EINVAL;
+        }
+      lock->runcount = 0;
+    }
+  else
+    {
+      /* Drop a reader lock.  */
+      if (!(lock->runcount > 0))
+        {
+          pthread_mutex_unlock (&lock->lock);
+          return EINVAL;
+        }
+      lock->runcount--;
+    }
+  if (lock->runcount == 0)
+    {
+      /* POSIX recommends that "write locks shall take precedence over read
+         locks", to avoid "writer starvation".  */
+      if (lock->waiting_writers_count > 0)
+        {
+          /* Wake up one of the waiting writers.  */
+          err = pthread_cond_signal (&lock->waiting_writers);
+          if (err != 0)
+            {
+              pthread_mutex_unlock (&lock->lock);
+              return err;
+            }
+        }
+      else
+        {
+          /* Wake up all waiting readers.  */
+          err = pthread_cond_broadcast (&lock->waiting_readers);
+          if (err != 0)
+            {
+              pthread_mutex_unlock (&lock->lock);
+              return err;
+            }
+        }
+    }
+  return pthread_mutex_unlock (&lock->lock);
+}
+
+int
+glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_destroy (&lock->lock);
+  if (err != 0)
+    return err;
+  err = pthread_cond_destroy (&lock->waiting_readers);
+  if (err != 0)
+    return err;
+  err = pthread_cond_destroy (&lock->waiting_writers);
+  if (err != 0)
+    return err;
+  return 0;
+}
+
+# endif
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+# if HAVE_PTHREAD_MUTEX_RECURSIVE
+
+#  if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
+
+int
+glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
+{
+  pthread_mutexattr_t attributes;
+  int err;
+
+  err = pthread_mutexattr_init (&attributes);
+  if (err != 0)
+    return err;
+  err = pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE);
+  if (err != 0)
+    {
+      pthread_mutexattr_destroy (&attributes);
+      return err;
+    }
+  err = pthread_mutex_init (lock, &attributes);
+  if (err != 0)
+    {
+      pthread_mutexattr_destroy (&attributes);
+      return err;
+    }
+  err = pthread_mutexattr_destroy (&attributes);
+  if (err != 0)
+    return err;
+  return 0;
+}
+
+#  else
+
+int
+glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
+{
+  pthread_mutexattr_t attributes;
+  int err;
+
+  err = pthread_mutexattr_init (&attributes);
+  if (err != 0)
+    return err;
+  err = pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE);
+  if (err != 0)
+    {
+      pthread_mutexattr_destroy (&attributes);
+      return err;
+    }
+  err = pthread_mutex_init (&lock->recmutex, &attributes);
+  if (err != 0)
+    {
+      pthread_mutexattr_destroy (&attributes);
+      return err;
+    }
+  err = pthread_mutexattr_destroy (&attributes);
+  if (err != 0)
+    return err;
+  lock->initialized = 1;
+  return 0;
+}
+
+int
+glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (!lock->initialized)
+    {
+      int err;
+
+      err = pthread_mutex_lock (&lock->guard);
+      if (err != 0)
+        return err;
+      if (!lock->initialized)
+        {
+          err = glthread_recursive_lock_init_multithreaded (lock);
+          if (err != 0)
+            {
+              pthread_mutex_unlock (&lock->guard);
+              return err;
+            }
+        }
+      err = pthread_mutex_unlock (&lock->guard);
+      if (err != 0)
+        return err;
+    }
+  return pthread_mutex_lock (&lock->recmutex);
+}
+
+int
+glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (!lock->initialized)
+    return EINVAL;
+  return pthread_mutex_unlock (&lock->recmutex);
+}
+
+int
+glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
+{
+  int err;
+
+  if (!lock->initialized)
+    return EINVAL;
+  err = pthread_mutex_destroy (&lock->recmutex);
+  if (err != 0)
+    return err;
+  lock->initialized = 0;
+  return 0;
+}
+
+#  endif
+
+# else
+
+int
+glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
+{
+  int err;
+
+  err = pthread_mutex_init (&lock->mutex, NULL);
+  if (err != 0)
+    return err;
+  lock->owner = (pthread_t) 0;
+  lock->depth = 0;
+  return 0;
+}
+
+int
+glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
+{
+  pthread_t self = pthread_self ();
+  if (lock->owner != self)
+    {
+      int err;
+
+      err = pthread_mutex_lock (&lock->mutex);
+      if (err != 0)
+        return err;
+      lock->owner = self;
+    }
+  if (++(lock->depth) == 0) /* wraparound? */
+    {
+      lock->depth--;
+      return EAGAIN;
+    }
+  return 0;
+}
+
+int
+glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != pthread_self ())
+    return EPERM;
+  if (lock->depth == 0)
+    return EINVAL;
+  if (--(lock->depth) == 0)
+    {
+      lock->owner = (pthread_t) 0;
+      return pthread_mutex_unlock (&lock->mutex);
+    }
+  else
+    return 0;
+}
+
+int
+glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != (pthread_t) 0)
+    return EBUSY;
+  return pthread_mutex_destroy (&lock->mutex);
+}
+
+# endif
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+static const pthread_once_t fresh_once = PTHREAD_ONCE_INIT;
+
+int
+glthread_once_singlethreaded (pthread_once_t *once_control)
+{
+  /* We don't know whether pthread_once_t is an integer type, a floating-point
+     type, a pointer type, or a structure type.  */
+  char *firstbyte = (char *)once_control;
+  if (*firstbyte == *(const char *)&fresh_once)
+    {
+      /* First time use of once_control.  Invert the first byte.  */
+      *firstbyte = ~ *(const char *)&fresh_once;
+      return 1;
+    }
+  else
+    return 0;
+}
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_PTH_THREADS
+
+/* Use the GNU Pth threads library.  */
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+static void
+glthread_once_call (void *arg)
+{
+  void (**gl_once_temp_addr) (void) = (void (**) (void)) arg;
+  void (*initfunction) (void) = *gl_once_temp_addr;
+  initfunction ();
+}
+
+int
+glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void))
+{
+  void (*temp) (void) = initfunction;
+  return (!pth_once (once_control, glthread_once_call, &temp) ? errno : 0);
+}
+
+int
+glthread_once_singlethreaded (pth_once_t *once_control)
+{
+  /* We know that pth_once_t is an integer type.  */
+  if (*once_control == PTH_ONCE_INIT)
+    {
+      /* First time use of once_control.  Invert the marker.  */
+      *once_control = ~ PTH_ONCE_INIT;
+      return 1;
+    }
+  else
+    return 0;
+}
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_SOLARIS_THREADS
+
+/* Use the old Solaris threads library.  */
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+int
+glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock)
+{
+  int err;
+
+  err = mutex_init (&lock->mutex, USYNC_THREAD, NULL);
+  if (err != 0)
+    return err;
+  lock->owner = (thread_t) 0;
+  lock->depth = 0;
+  return 0;
+}
+
+int
+glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock)
+{
+  thread_t self = thr_self ();
+  if (lock->owner != self)
+    {
+      int err;
+
+      err = mutex_lock (&lock->mutex);
+      if (err != 0)
+        return err;
+      lock->owner = self;
+    }
+  if (++(lock->depth) == 0) /* wraparound? */
+    {
+      lock->depth--;
+      return EAGAIN;
+    }
+  return 0;
+}
+
+int
+glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != thr_self ())
+    return EPERM;
+  if (lock->depth == 0)
+    return EINVAL;
+  if (--(lock->depth) == 0)
+    {
+      lock->owner = (thread_t) 0;
+      return mutex_unlock (&lock->mutex);
+    }
+  else
+    return 0;
+}
+
+int
+glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != (thread_t) 0)
+    return EBUSY;
+  return mutex_destroy (&lock->mutex);
+}
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+int
+glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void))
+{
+  if (!once_control->inited)
+    {
+      int err;
+
+      /* Use the mutex to guarantee that if another thread is already calling
+         the initfunction, this thread waits until it's finished.  */
+      err = mutex_lock (&once_control->mutex);
+      if (err != 0)
+        return err;
+      if (!once_control->inited)
+        {
+          once_control->inited = 1;
+          initfunction ();
+        }
+      return mutex_unlock (&once_control->mutex);
+    }
+  else
+    return 0;
+}
+
+int
+glthread_once_singlethreaded (gl_once_t *once_control)
+{
+  /* We know that gl_once_t contains an integer type.  */
+  if (!once_control->inited)
+    {
+      /* First time use of once_control.  Invert the marker.  */
+      once_control->inited = ~ 0;
+      return 1;
+    }
+  else
+    return 0;
+}
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_WINDOWS_THREADS
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+void
+glthread_lock_init_func (gl_lock_t *lock)
+{
+  InitializeCriticalSection (&lock->lock);
+  lock->guard.done = 1;
+}
+
+int
+glthread_lock_lock_func (gl_lock_t *lock)
+{
+  if (!lock->guard.done)
+    {
+      if (InterlockedIncrement (&lock->guard.started) == 0)
+        /* This thread is the first one to need this lock.  Initialize it.  */
+        glthread_lock_init (lock);
+      else
+        /* Yield the CPU while waiting for another thread to finish
+           initializing this lock.  */
+        while (!lock->guard.done)
+          Sleep (0);
+    }
+  EnterCriticalSection (&lock->lock);
+  return 0;
+}
+
+int
+glthread_lock_unlock_func (gl_lock_t *lock)
+{
+  if (!lock->guard.done)
+    return EINVAL;
+  LeaveCriticalSection (&lock->lock);
+  return 0;
+}
+
+int
+glthread_lock_destroy_func (gl_lock_t *lock)
+{
+  if (!lock->guard.done)
+    return EINVAL;
+  DeleteCriticalSection (&lock->lock);
+  lock->guard.done = 0;
+  return 0;
+}
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+/* In this file, the waitqueues are implemented as circular arrays.  */
+#define gl_waitqueue_t gl_carray_waitqueue_t
+
+static void
+gl_waitqueue_init (gl_waitqueue_t *wq)
+{
+  wq->array = NULL;
+  wq->count = 0;
+  wq->alloc = 0;
+  wq->offset = 0;
+}
+
+/* Enqueues the current thread, represented by an event, in a wait queue.
+   Returns INVALID_HANDLE_VALUE if an allocation failure occurs.  */
+static HANDLE
+gl_waitqueue_add (gl_waitqueue_t *wq)
+{
+  HANDLE event;
+  unsigned int index;
+
+  if (wq->count == wq->alloc)
+    {
+      unsigned int new_alloc = 2 * wq->alloc + 1;
+      HANDLE *new_array =
+        (HANDLE *) realloc (wq->array, new_alloc * sizeof (HANDLE));
+      if (new_array == NULL)
+        /* No more memory.  */
+        return INVALID_HANDLE_VALUE;
+      /* Now is a good opportunity to rotate the array so that its contents
+         starts at offset 0.  */
+      if (wq->offset > 0)
+        {
+          unsigned int old_count = wq->count;
+          unsigned int old_alloc = wq->alloc;
+          unsigned int old_offset = wq->offset;
+          unsigned int i;
+          if (old_offset + old_count > old_alloc)
+            {
+              unsigned int limit = old_offset + old_count - old_alloc;
+              for (i = 0; i < limit; i++)
+                new_array[old_alloc + i] = new_array[i];
+            }
+          for (i = 0; i < old_count; i++)
+            new_array[i] = new_array[old_offset + i];
+          wq->offset = 0;
+        }
+      wq->array = new_array;
+      wq->alloc = new_alloc;
+    }
+  /* Whether the created event is a manual-reset one or an auto-reset one,
+     does not matter, since we will wait on it only once.  */
+  event = CreateEvent (NULL, TRUE, FALSE, NULL);
+  if (event == INVALID_HANDLE_VALUE)
+    /* No way to allocate an event.  */
+    return INVALID_HANDLE_VALUE;
+  index = wq->offset + wq->count;
+  if (index >= wq->alloc)
+    index -= wq->alloc;
+  wq->array[index] = event;
+  wq->count++;
+  return event;
+}
+
+/* Notifies the first thread from a wait queue and dequeues it.  */
+static void
+gl_waitqueue_notify_first (gl_waitqueue_t *wq)
+{
+  SetEvent (wq->array[wq->offset + 0]);
+  wq->offset++;
+  wq->count--;
+  if (wq->count == 0 || wq->offset == wq->alloc)
+    wq->offset = 0;
+}
+
+/* Notifies all threads from a wait queue and dequeues them all.  */
+static void
+gl_waitqueue_notify_all (gl_waitqueue_t *wq)
+{
+  unsigned int i;
+
+  for (i = 0; i < wq->count; i++)
+    {
+      unsigned int index = wq->offset + i;
+      if (index >= wq->alloc)
+        index -= wq->alloc;
+      SetEvent (wq->array[index]);
+    }
+  wq->count = 0;
+  wq->offset = 0;
+}
+
+void
+glthread_rwlock_init_func (gl_rwlock_t *lock)
+{
+  InitializeCriticalSection (&lock->lock);
+  gl_waitqueue_init (&lock->waiting_readers);
+  gl_waitqueue_init (&lock->waiting_writers);
+  lock->runcount = 0;
+  lock->guard.done = 1;
+}
+
+int
+glthread_rwlock_rdlock_func (gl_rwlock_t *lock)
+{
+  if (!lock->guard.done)
+    {
+      if (InterlockedIncrement (&lock->guard.started) == 0)
+        /* This thread is the first one to need this lock.  Initialize it.  */
+        glthread_rwlock_init (lock);
+      else
+        /* Yield the CPU while waiting for another thread to finish
+           initializing this lock.  */
+        while (!lock->guard.done)
+          Sleep (0);
+    }
+  EnterCriticalSection (&lock->lock);
+  /* Test whether only readers are currently running, and whether the runcount
+     field will not overflow.  */
+  if (!(lock->runcount + 1 > 0))
+    {
+      /* This thread has to wait for a while.  Enqueue it among the
+         waiting_readers.  */
+      HANDLE event = gl_waitqueue_add (&lock->waiting_readers);
+      if (event != INVALID_HANDLE_VALUE)
+        {
+          DWORD result;
+          LeaveCriticalSection (&lock->lock);
+          /* Wait until another thread signals this event.  */
+          result = WaitForSingleObject (event, INFINITE);
+          if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
+            abort ();
+          CloseHandle (event);
+          /* The thread which signalled the event already did the bookkeeping:
+             removed us from the waiting_readers, incremented lock->runcount.  */
+          if (!(lock->runcount > 0))
+            abort ();
+          return 0;
+        }
+      else
+        {
+          /* Allocation failure.  Weird.  */
+          do
+            {
+              LeaveCriticalSection (&lock->lock);
+              Sleep (1);
+              EnterCriticalSection (&lock->lock);
+            }
+          while (!(lock->runcount + 1 > 0));
+        }
+    }
+  lock->runcount++;
+  LeaveCriticalSection (&lock->lock);
+  return 0;
+}
+
+int
+glthread_rwlock_wrlock_func (gl_rwlock_t *lock)
+{
+  if (!lock->guard.done)
+    {
+      if (InterlockedIncrement (&lock->guard.started) == 0)
+        /* This thread is the first one to need this lock.  Initialize it.  */
+        glthread_rwlock_init (lock);
+      else
+        /* Yield the CPU while waiting for another thread to finish
+           initializing this lock.  */
+        while (!lock->guard.done)
+          Sleep (0);
+    }
+  EnterCriticalSection (&lock->lock);
+  /* Test whether no readers or writers are currently running.  */
+  if (!(lock->runcount == 0))
+    {
+      /* This thread has to wait for a while.  Enqueue it among the
+         waiting_writers.  */
+      HANDLE event = gl_waitqueue_add (&lock->waiting_writers);
+      if (event != INVALID_HANDLE_VALUE)
+        {
+          DWORD result;
+          LeaveCriticalSection (&lock->lock);
+          /* Wait until another thread signals this event.  */
+          result = WaitForSingleObject (event, INFINITE);
+          if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
+            abort ();
+          CloseHandle (event);
+          /* The thread which signalled the event already did the bookkeeping:
+             removed us from the waiting_writers, set lock->runcount = -1.  */
+          if (!(lock->runcount == -1))
+            abort ();
+          return 0;
+        }
+      else
+        {
+          /* Allocation failure.  Weird.  */
+          do
+            {
+              LeaveCriticalSection (&lock->lock);
+              Sleep (1);
+              EnterCriticalSection (&lock->lock);
+            }
+          while (!(lock->runcount == 0));
+        }
+    }
+  lock->runcount--; /* runcount becomes -1 */
+  LeaveCriticalSection (&lock->lock);
+  return 0;
+}
+
+int
+glthread_rwlock_unlock_func (gl_rwlock_t *lock)
+{
+  if (!lock->guard.done)
+    return EINVAL;
+  EnterCriticalSection (&lock->lock);
+  if (lock->runcount < 0)
+    {
+      /* Drop a writer lock.  */
+      if (!(lock->runcount == -1))
+        abort ();
+      lock->runcount = 0;
+    }
+  else
+    {
+      /* Drop a reader lock.  */
+      if (!(lock->runcount > 0))
+        {
+          LeaveCriticalSection (&lock->lock);
+          return EPERM;
+        }
+      lock->runcount--;
+    }
+  if (lock->runcount == 0)
+    {
+      /* POSIX recommends that "write locks shall take precedence over read
+         locks", to avoid "writer starvation".  */
+      if (lock->waiting_writers.count > 0)
+        {
+          /* Wake up one of the waiting writers.  */
+          lock->runcount--;
+          gl_waitqueue_notify_first (&lock->waiting_writers);
+        }
+      else
+        {
+          /* Wake up all waiting readers.  */
+          lock->runcount += lock->waiting_readers.count;
+          gl_waitqueue_notify_all (&lock->waiting_readers);
+        }
+    }
+  LeaveCriticalSection (&lock->lock);
+  return 0;
+}
+
+int
+glthread_rwlock_destroy_func (gl_rwlock_t *lock)
+{
+  if (!lock->guard.done)
+    return EINVAL;
+  if (lock->runcount != 0)
+    return EBUSY;
+  DeleteCriticalSection (&lock->lock);
+  if (lock->waiting_readers.array != NULL)
+    free (lock->waiting_readers.array);
+  if (lock->waiting_writers.array != NULL)
+    free (lock->waiting_writers.array);
+  lock->guard.done = 0;
+  return 0;
+}
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+void
+glthread_recursive_lock_init_func (gl_recursive_lock_t *lock)
+{
+  lock->owner = 0;
+  lock->depth = 0;
+  InitializeCriticalSection (&lock->lock);
+  lock->guard.done = 1;
+}
+
+int
+glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock)
+{
+  if (!lock->guard.done)
+    {
+      if (InterlockedIncrement (&lock->guard.started) == 0)
+        /* This thread is the first one to need this lock.  Initialize it.  */
+        glthread_recursive_lock_init (lock);
+      else
+        /* Yield the CPU while waiting for another thread to finish
+           initializing this lock.  */
+        while (!lock->guard.done)
+          Sleep (0);
+    }
+  {
+    DWORD self = GetCurrentThreadId ();
+    if (lock->owner != self)
+      {
+        EnterCriticalSection (&lock->lock);
+        lock->owner = self;
+      }
+    if (++(lock->depth) == 0) /* wraparound? */
+      {
+        lock->depth--;
+        return EAGAIN;
+      }
+  }
+  return 0;
+}
+
+int
+glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != GetCurrentThreadId ())
+    return EPERM;
+  if (lock->depth == 0)
+    return EINVAL;
+  if (--(lock->depth) == 0)
+    {
+      lock->owner = 0;
+      LeaveCriticalSection (&lock->lock);
+    }
+  return 0;
+}
+
+int
+glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock)
+{
+  if (lock->owner != 0)
+    return EBUSY;
+  DeleteCriticalSection (&lock->lock);
+  lock->guard.done = 0;
+  return 0;
+}
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+void
+glthread_once_func (gl_once_t *once_control, void (*initfunction) (void))
+{
+  if (once_control->inited <= 0)
+    {
+      if (InterlockedIncrement (&once_control->started) == 0)
+        {
+          /* This thread is the first one to come to this once_control.  */
+          InitializeCriticalSection (&once_control->lock);
+          EnterCriticalSection (&once_control->lock);
+          once_control->inited = 0;
+          initfunction ();
+          once_control->inited = 1;
+          LeaveCriticalSection (&once_control->lock);
+        }
+      else
+        {
+          /* Undo last operation.  */
+          InterlockedDecrement (&once_control->started);
+          /* Some other thread has already started the initialization.
+             Yield the CPU while waiting for the other thread to finish
+             initializing and taking the lock.  */
+          while (once_control->inited < 0)
+            Sleep (0);
+          if (once_control->inited <= 0)
+            {
+              /* Take the lock.  This blocks until the other thread has
+                 finished calling the initfunction.  */
+              EnterCriticalSection (&once_control->lock);
+              LeaveCriticalSection (&once_control->lock);
+              if (!(once_control->inited > 0))
+                abort ();
+            }
+        }
+    }
+}
+
+#endif
+
+/* ========================================================================= */
diff --git a/gnulib/import/glthread/lock.h b/gnulib/import/glthread/lock.h
new file mode 100644
index 0000000..e64506b
--- /dev/null
+++ b/gnulib/import/glthread/lock.h
@@ -0,0 +1,927 @@ 
+/* Locking in multithreaded situations.
+   Copyright (C) 2005-2016 Free Software Foundation, Inc.
+
+   This program 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, or (at your option)
+   any later version.
+
+   This program 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 program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005.
+   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
+   gthr-win32.h.  */
+
+/* This file contains locking primitives for use with a given thread library.
+   It does not contain primitives for creating threads or for other
+   synchronization primitives.
+
+   Normal (non-recursive) locks:
+     Type:                gl_lock_t
+     Declaration:         gl_lock_define(extern, name)
+     Initializer:         gl_lock_define_initialized(, name)
+     Initialization:      gl_lock_init (name);
+     Taking the lock:     gl_lock_lock (name);
+     Releasing the lock:  gl_lock_unlock (name);
+     De-initialization:   gl_lock_destroy (name);
+   Equivalent functions with control of error handling:
+     Initialization:      err = glthread_lock_init (&name);
+     Taking the lock:     err = glthread_lock_lock (&name);
+     Releasing the lock:  err = glthread_lock_unlock (&name);
+     De-initialization:   err = glthread_lock_destroy (&name);
+
+   Read-Write (non-recursive) locks:
+     Type:                gl_rwlock_t
+     Declaration:         gl_rwlock_define(extern, name)
+     Initializer:         gl_rwlock_define_initialized(, name)
+     Initialization:      gl_rwlock_init (name);
+     Taking the lock:     gl_rwlock_rdlock (name);
+                          gl_rwlock_wrlock (name);
+     Releasing the lock:  gl_rwlock_unlock (name);
+     De-initialization:   gl_rwlock_destroy (name);
+   Equivalent functions with control of error handling:
+     Initialization:      err = glthread_rwlock_init (&name);
+     Taking the lock:     err = glthread_rwlock_rdlock (&name);
+                          err = glthread_rwlock_wrlock (&name);
+     Releasing the lock:  err = glthread_rwlock_unlock (&name);
+     De-initialization:   err = glthread_rwlock_destroy (&name);
+
+   Recursive locks:
+     Type:                gl_recursive_lock_t
+     Declaration:         gl_recursive_lock_define(extern, name)
+     Initializer:         gl_recursive_lock_define_initialized(, name)
+     Initialization:      gl_recursive_lock_init (name);
+     Taking the lock:     gl_recursive_lock_lock (name);
+     Releasing the lock:  gl_recursive_lock_unlock (name);
+     De-initialization:   gl_recursive_lock_destroy (name);
+   Equivalent functions with control of error handling:
+     Initialization:      err = glthread_recursive_lock_init (&name);
+     Taking the lock:     err = glthread_recursive_lock_lock (&name);
+     Releasing the lock:  err = glthread_recursive_lock_unlock (&name);
+     De-initialization:   err = glthread_recursive_lock_destroy (&name);
+
+  Once-only execution:
+     Type:                gl_once_t
+     Initializer:         gl_once_define(extern, name)
+     Execution:           gl_once (name, initfunction);
+   Equivalent functions with control of error handling:
+     Execution:           err = glthread_once (&name, initfunction);
+*/
+
+
+#ifndef _LOCK_H
+#define _LOCK_H
+
+#include <errno.h>
+#include <stdlib.h>
+
+/* ========================================================================= */
+
+#if USE_POSIX_THREADS
+
+/* Use the POSIX threads library.  */
+
+# include <pthread.h>
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+# if PTHREAD_IN_USE_DETECTION_HARD
+
+/* The pthread_in_use() detection needs to be done at runtime.  */
+#  define pthread_in_use() \
+     glthread_in_use ()
+extern int glthread_in_use (void);
+
+# endif
+
+# if USE_POSIX_THREADS_WEAK
+
+/* Use weak references to the POSIX threads library.  */
+
+/* Weak references avoid dragging in external libraries if the other parts
+   of the program don't use them.  Here we use them, because we don't want
+   every program that uses libintl to depend on libpthread.  This assumes
+   that libpthread would not be loaded after libintl; i.e. if libintl is
+   loaded first, by an executable that does not depend on libpthread, and
+   then a module is dynamically loaded that depends on libpthread, libintl
+   will not be multithread-safe.  */
+
+/* The way to test at runtime whether libpthread is present is to test
+   whether a function pointer's value, such as &pthread_mutex_init, is
+   non-NULL.  However, some versions of GCC have a bug through which, in
+   PIC mode, &foo != NULL always evaluates to true if there is a direct
+   call to foo(...) in the same function.  To avoid this, we test the
+   address of a function in libpthread that we don't use.  */
+
+#  pragma weak pthread_mutex_init
+#  pragma weak pthread_mutex_lock
+#  pragma weak pthread_mutex_unlock
+#  pragma weak pthread_mutex_destroy
+#  pragma weak pthread_rwlock_init
+#  pragma weak pthread_rwlock_rdlock
+#  pragma weak pthread_rwlock_wrlock
+#  pragma weak pthread_rwlock_unlock
+#  pragma weak pthread_rwlock_destroy
+#  pragma weak pthread_once
+#  pragma weak pthread_cond_init
+#  pragma weak pthread_cond_wait
+#  pragma weak pthread_cond_signal
+#  pragma weak pthread_cond_broadcast
+#  pragma weak pthread_cond_destroy
+#  pragma weak pthread_mutexattr_init
+#  pragma weak pthread_mutexattr_settype
+#  pragma weak pthread_mutexattr_destroy
+#  ifndef pthread_self
+#   pragma weak pthread_self
+#  endif
+
+#  if !PTHREAD_IN_USE_DETECTION_HARD
+#   pragma weak pthread_cancel
+#   define pthread_in_use() (pthread_cancel != NULL)
+#  endif
+
+# else
+
+#  if !PTHREAD_IN_USE_DETECTION_HARD
+#   define pthread_in_use() 1
+#  endif
+
+# endif
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+typedef pthread_mutex_t gl_lock_t;
+# define gl_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS pthread_mutex_t NAME;
+# define gl_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS pthread_mutex_t NAME = gl_lock_initializer;
+# define gl_lock_initializer \
+    PTHREAD_MUTEX_INITIALIZER
+# define glthread_lock_init(LOCK) \
+    (pthread_in_use () ? pthread_mutex_init (LOCK, NULL) : 0)
+# define glthread_lock_lock(LOCK) \
+    (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
+# define glthread_lock_unlock(LOCK) \
+    (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
+# define glthread_lock_destroy(LOCK) \
+    (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+# if HAVE_PTHREAD_RWLOCK
+
+#  ifdef PTHREAD_RWLOCK_INITIALIZER
+
+typedef pthread_rwlock_t gl_rwlock_t;
+#   define gl_rwlock_define(STORAGECLASS, NAME) \
+      STORAGECLASS pthread_rwlock_t NAME;
+#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+      STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer;
+#   define gl_rwlock_initializer \
+      PTHREAD_RWLOCK_INITIALIZER
+#   define glthread_rwlock_init(LOCK) \
+      (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
+#   define glthread_rwlock_rdlock(LOCK) \
+      (pthread_in_use () ? pthread_rwlock_rdlock (LOCK) : 0)
+#   define glthread_rwlock_wrlock(LOCK) \
+      (pthread_in_use () ? pthread_rwlock_wrlock (LOCK) : 0)
+#   define glthread_rwlock_unlock(LOCK) \
+      (pthread_in_use () ? pthread_rwlock_unlock (LOCK) : 0)
+#   define glthread_rwlock_destroy(LOCK) \
+      (pthread_in_use () ? pthread_rwlock_destroy (LOCK) : 0)
+
+#  else
+
+typedef struct
+        {
+          int initialized;
+          pthread_mutex_t guard;   /* protects the initialization */
+          pthread_rwlock_t rwlock; /* read-write lock */
+        }
+        gl_rwlock_t;
+#   define gl_rwlock_define(STORAGECLASS, NAME) \
+      STORAGECLASS gl_rwlock_t NAME;
+#   define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+      STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
+#   define gl_rwlock_initializer \
+      { 0, PTHREAD_MUTEX_INITIALIZER }
+#   define glthread_rwlock_init(LOCK) \
+      (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
+#   define glthread_rwlock_rdlock(LOCK) \
+      (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
+#   define glthread_rwlock_wrlock(LOCK) \
+      (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
+#   define glthread_rwlock_unlock(LOCK) \
+      (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
+#   define glthread_rwlock_destroy(LOCK) \
+      (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
+
+#  endif
+
+# else
+
+typedef struct
+        {
+          pthread_mutex_t lock; /* protects the remaining fields */
+          pthread_cond_t waiting_readers; /* waiting readers */
+          pthread_cond_t waiting_writers; /* waiting writers */
+          unsigned int waiting_writers_count; /* number of waiting writers */
+          int runcount; /* number of readers running, or -1 when a writer runs */
+        }
+        gl_rwlock_t;
+# define gl_rwlock_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_rwlock_t NAME;
+# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
+# define gl_rwlock_initializer \
+    { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0 }
+# define glthread_rwlock_init(LOCK) \
+    (pthread_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
+# define glthread_rwlock_rdlock(LOCK) \
+    (pthread_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_wrlock(LOCK) \
+    (pthread_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_unlock(LOCK) \
+    (pthread_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_destroy(LOCK) \
+    (pthread_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
+
+# endif
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+# if HAVE_PTHREAD_MUTEX_RECURSIVE
+
+#  if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
+
+typedef pthread_mutex_t gl_recursive_lock_t;
+#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
+      STORAGECLASS pthread_mutex_t NAME;
+#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+      STORAGECLASS pthread_mutex_t NAME = gl_recursive_lock_initializer;
+#   ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER
+#    define gl_recursive_lock_initializer \
+       PTHREAD_RECURSIVE_MUTEX_INITIALIZER
+#   else
+#    define gl_recursive_lock_initializer \
+       PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
+#   endif
+#   define glthread_recursive_lock_init(LOCK) \
+      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
+#   define glthread_recursive_lock_lock(LOCK) \
+      (pthread_in_use () ? pthread_mutex_lock (LOCK) : 0)
+#   define glthread_recursive_lock_unlock(LOCK) \
+      (pthread_in_use () ? pthread_mutex_unlock (LOCK) : 0)
+#   define glthread_recursive_lock_destroy(LOCK) \
+      (pthread_in_use () ? pthread_mutex_destroy (LOCK) : 0)
+extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
+
+#  else
+
+typedef struct
+        {
+          pthread_mutex_t recmutex; /* recursive mutex */
+          pthread_mutex_t guard;    /* protects the initialization */
+          int initialized;
+        }
+        gl_recursive_lock_t;
+#   define gl_recursive_lock_define(STORAGECLASS, NAME) \
+      STORAGECLASS gl_recursive_lock_t NAME;
+#   define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+      STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
+#   define gl_recursive_lock_initializer \
+      { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, 0 }
+#   define glthread_recursive_lock_init(LOCK) \
+      (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
+#   define glthread_recursive_lock_lock(LOCK) \
+      (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
+#   define glthread_recursive_lock_unlock(LOCK) \
+      (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
+#   define glthread_recursive_lock_destroy(LOCK) \
+      (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
+
+#  endif
+
+# else
+
+/* Old versions of POSIX threads on Solaris did not have recursive locks.
+   We have to implement them ourselves.  */
+
+typedef struct
+        {
+          pthread_mutex_t mutex;
+          pthread_t owner;
+          unsigned long depth;
+        }
+        gl_recursive_lock_t;
+#  define gl_recursive_lock_define(STORAGECLASS, NAME) \
+     STORAGECLASS gl_recursive_lock_t NAME;
+#  define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+     STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
+#  define gl_recursive_lock_initializer \
+     { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, 0 }
+#  define glthread_recursive_lock_init(LOCK) \
+     (pthread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
+#  define glthread_recursive_lock_lock(LOCK) \
+     (pthread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
+#  define glthread_recursive_lock_unlock(LOCK) \
+     (pthread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
+#  define glthread_recursive_lock_destroy(LOCK) \
+     (pthread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
+
+# endif
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+typedef pthread_once_t gl_once_t;
+# define gl_once_define(STORAGECLASS, NAME) \
+    STORAGECLASS pthread_once_t NAME = PTHREAD_ONCE_INIT;
+# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
+    (pthread_in_use ()                                                         \
+     ? pthread_once (ONCE_CONTROL, INITFUNCTION)                               \
+     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
+extern int glthread_once_singlethreaded (pthread_once_t *once_control);
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_PTH_THREADS
+
+/* Use the GNU Pth threads library.  */
+
+# include <pth.h>
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+# if USE_PTH_THREADS_WEAK
+
+/* Use weak references to the GNU Pth threads library.  */
+
+#  pragma weak pth_mutex_init
+#  pragma weak pth_mutex_acquire
+#  pragma weak pth_mutex_release
+#  pragma weak pth_rwlock_init
+#  pragma weak pth_rwlock_acquire
+#  pragma weak pth_rwlock_release
+#  pragma weak pth_once
+
+#  pragma weak pth_cancel
+#  define pth_in_use() (pth_cancel != NULL)
+
+# else
+
+#  define pth_in_use() 1
+
+# endif
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+typedef pth_mutex_t gl_lock_t;
+# define gl_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS pth_mutex_t NAME;
+# define gl_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS pth_mutex_t NAME = gl_lock_initializer;
+# define gl_lock_initializer \
+    PTH_MUTEX_INIT
+# define glthread_lock_init(LOCK) \
+    (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
+# define glthread_lock_lock(LOCK) \
+    (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
+# define glthread_lock_unlock(LOCK) \
+    (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
+# define glthread_lock_destroy(LOCK) \
+    ((void)(LOCK), 0)
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+typedef pth_rwlock_t gl_rwlock_t;
+#  define gl_rwlock_define(STORAGECLASS, NAME) \
+     STORAGECLASS pth_rwlock_t NAME;
+#  define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+     STORAGECLASS pth_rwlock_t NAME = gl_rwlock_initializer;
+#  define gl_rwlock_initializer \
+     PTH_RWLOCK_INIT
+#  define glthread_rwlock_init(LOCK) \
+     (pth_in_use () && !pth_rwlock_init (LOCK) ? errno : 0)
+#  define glthread_rwlock_rdlock(LOCK) \
+     (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RD, 0, NULL) ? errno : 0)
+#  define glthread_rwlock_wrlock(LOCK) \
+     (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RW, 0, NULL) ? errno : 0)
+#  define glthread_rwlock_unlock(LOCK) \
+     (pth_in_use () && !pth_rwlock_release (LOCK) ? errno : 0)
+#  define glthread_rwlock_destroy(LOCK) \
+     ((void)(LOCK), 0)
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+/* In Pth, mutexes are recursive by default.  */
+typedef pth_mutex_t gl_recursive_lock_t;
+#  define gl_recursive_lock_define(STORAGECLASS, NAME) \
+     STORAGECLASS pth_mutex_t NAME;
+#  define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+     STORAGECLASS pth_mutex_t NAME = gl_recursive_lock_initializer;
+#  define gl_recursive_lock_initializer \
+     PTH_MUTEX_INIT
+#  define glthread_recursive_lock_init(LOCK) \
+     (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0)
+#  define glthread_recursive_lock_lock(LOCK) \
+     (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0)
+#  define glthread_recursive_lock_unlock(LOCK) \
+     (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0)
+#  define glthread_recursive_lock_destroy(LOCK) \
+     ((void)(LOCK), 0)
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+typedef pth_once_t gl_once_t;
+# define gl_once_define(STORAGECLASS, NAME) \
+    STORAGECLASS pth_once_t NAME = PTH_ONCE_INIT;
+# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
+    (pth_in_use ()                                                             \
+     ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION)                \
+     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
+extern int glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void));
+extern int glthread_once_singlethreaded (pth_once_t *once_control);
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_SOLARIS_THREADS
+
+/* Use the old Solaris threads library.  */
+
+# include <thread.h>
+# include <synch.h>
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+# if USE_SOLARIS_THREADS_WEAK
+
+/* Use weak references to the old Solaris threads library.  */
+
+#  pragma weak mutex_init
+#  pragma weak mutex_lock
+#  pragma weak mutex_unlock
+#  pragma weak mutex_destroy
+#  pragma weak rwlock_init
+#  pragma weak rw_rdlock
+#  pragma weak rw_wrlock
+#  pragma weak rw_unlock
+#  pragma weak rwlock_destroy
+#  pragma weak thr_self
+
+#  pragma weak thr_suspend
+#  define thread_in_use() (thr_suspend != NULL)
+
+# else
+
+#  define thread_in_use() 1
+
+# endif
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+typedef mutex_t gl_lock_t;
+# define gl_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS mutex_t NAME;
+# define gl_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS mutex_t NAME = gl_lock_initializer;
+# define gl_lock_initializer \
+    DEFAULTMUTEX
+# define glthread_lock_init(LOCK) \
+    (thread_in_use () ? mutex_init (LOCK, USYNC_THREAD, NULL) : 0)
+# define glthread_lock_lock(LOCK) \
+    (thread_in_use () ? mutex_lock (LOCK) : 0)
+# define glthread_lock_unlock(LOCK) \
+    (thread_in_use () ? mutex_unlock (LOCK) : 0)
+# define glthread_lock_destroy(LOCK) \
+    (thread_in_use () ? mutex_destroy (LOCK) : 0)
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+typedef rwlock_t gl_rwlock_t;
+# define gl_rwlock_define(STORAGECLASS, NAME) \
+    STORAGECLASS rwlock_t NAME;
+# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS rwlock_t NAME = gl_rwlock_initializer;
+# define gl_rwlock_initializer \
+    DEFAULTRWLOCK
+# define glthread_rwlock_init(LOCK) \
+    (thread_in_use () ? rwlock_init (LOCK, USYNC_THREAD, NULL) : 0)
+# define glthread_rwlock_rdlock(LOCK) \
+    (thread_in_use () ? rw_rdlock (LOCK) : 0)
+# define glthread_rwlock_wrlock(LOCK) \
+    (thread_in_use () ? rw_wrlock (LOCK) : 0)
+# define glthread_rwlock_unlock(LOCK) \
+    (thread_in_use () ? rw_unlock (LOCK) : 0)
+# define glthread_rwlock_destroy(LOCK) \
+    (thread_in_use () ? rwlock_destroy (LOCK) : 0)
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+/* Old Solaris threads did not have recursive locks.
+   We have to implement them ourselves.  */
+
+typedef struct
+        {
+          mutex_t mutex;
+          thread_t owner;
+          unsigned long depth;
+        }
+        gl_recursive_lock_t;
+# define gl_recursive_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_recursive_lock_t NAME;
+# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
+# define gl_recursive_lock_initializer \
+    { DEFAULTMUTEX, (thread_t) 0, 0 }
+# define glthread_recursive_lock_init(LOCK) \
+    (thread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0)
+# define glthread_recursive_lock_lock(LOCK) \
+    (thread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0)
+# define glthread_recursive_lock_unlock(LOCK) \
+    (thread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0)
+# define glthread_recursive_lock_destroy(LOCK) \
+    (thread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock);
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+typedef struct
+        {
+          volatile int inited;
+          mutex_t mutex;
+        }
+        gl_once_t;
+# define gl_once_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_once_t NAME = { 0, DEFAULTMUTEX };
+# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
+    (thread_in_use ()                                                          \
+     ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION)                \
+     : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0))
+extern int glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void));
+extern int glthread_once_singlethreaded (gl_once_t *once_control);
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+#if USE_WINDOWS_THREADS
+
+# define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+# include <windows.h>
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+/* We can use CRITICAL_SECTION directly, rather than the native Windows Event,
+   Mutex, Semaphore types, because
+     - we need only to synchronize inside a single process (address space),
+       not inter-process locking,
+     - we don't need to support trylock operations.  (TryEnterCriticalSection
+       does not work on Windows 95/98/ME.  Packages that need trylock usually
+       define their own mutex type.)  */
+
+/* There is no way to statically initialize a CRITICAL_SECTION.  It needs
+   to be done lazily, once only.  For this we need spinlocks.  */
+
+typedef struct { volatile int done; volatile long started; } gl_spinlock_t;
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+typedef struct
+        {
+          gl_spinlock_t guard; /* protects the initialization */
+          CRITICAL_SECTION lock;
+        }
+        gl_lock_t;
+# define gl_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_lock_t NAME;
+# define gl_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS gl_lock_t NAME = gl_lock_initializer;
+# define gl_lock_initializer \
+    { { 0, -1 } }
+# define glthread_lock_init(LOCK) \
+    (glthread_lock_init_func (LOCK), 0)
+# define glthread_lock_lock(LOCK) \
+    glthread_lock_lock_func (LOCK)
+# define glthread_lock_unlock(LOCK) \
+    glthread_lock_unlock_func (LOCK)
+# define glthread_lock_destroy(LOCK) \
+    glthread_lock_destroy_func (LOCK)
+extern void glthread_lock_init_func (gl_lock_t *lock);
+extern int glthread_lock_lock_func (gl_lock_t *lock);
+extern int glthread_lock_unlock_func (gl_lock_t *lock);
+extern int glthread_lock_destroy_func (gl_lock_t *lock);
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+/* It is impossible to implement read-write locks using plain locks, without
+   introducing an extra thread dedicated to managing read-write locks.
+   Therefore here we need to use the low-level Event type.  */
+
+typedef struct
+        {
+          HANDLE *array; /* array of waiting threads, each represented by an event */
+          unsigned int count; /* number of waiting threads */
+          unsigned int alloc; /* length of allocated array */
+          unsigned int offset; /* index of first waiting thread in array */
+        }
+        gl_carray_waitqueue_t;
+typedef struct
+        {
+          gl_spinlock_t guard; /* protects the initialization */
+          CRITICAL_SECTION lock; /* protects the remaining fields */
+          gl_carray_waitqueue_t waiting_readers; /* waiting readers */
+          gl_carray_waitqueue_t waiting_writers; /* waiting writers */
+          int runcount; /* number of readers running, or -1 when a writer runs */
+        }
+        gl_rwlock_t;
+# define gl_rwlock_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_rwlock_t NAME;
+# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
+# define gl_rwlock_initializer \
+    { { 0, -1 } }
+# define glthread_rwlock_init(LOCK) \
+    (glthread_rwlock_init_func (LOCK), 0)
+# define glthread_rwlock_rdlock(LOCK) \
+    glthread_rwlock_rdlock_func (LOCK)
+# define glthread_rwlock_wrlock(LOCK) \
+    glthread_rwlock_wrlock_func (LOCK)
+# define glthread_rwlock_unlock(LOCK) \
+    glthread_rwlock_unlock_func (LOCK)
+# define glthread_rwlock_destroy(LOCK) \
+    glthread_rwlock_destroy_func (LOCK)
+extern void glthread_rwlock_init_func (gl_rwlock_t *lock);
+extern int glthread_rwlock_rdlock_func (gl_rwlock_t *lock);
+extern int glthread_rwlock_wrlock_func (gl_rwlock_t *lock);
+extern int glthread_rwlock_unlock_func (gl_rwlock_t *lock);
+extern int glthread_rwlock_destroy_func (gl_rwlock_t *lock);
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+/* The native Windows documentation says that CRITICAL_SECTION already
+   implements a recursive lock.  But we need not rely on it: It's easy to
+   implement a recursive lock without this assumption.  */
+
+typedef struct
+        {
+          gl_spinlock_t guard; /* protects the initialization */
+          DWORD owner;
+          unsigned long depth;
+          CRITICAL_SECTION lock;
+        }
+        gl_recursive_lock_t;
+# define gl_recursive_lock_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_recursive_lock_t NAME;
+# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \
+    STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer;
+# define gl_recursive_lock_initializer \
+    { { 0, -1 }, 0, 0 }
+# define glthread_recursive_lock_init(LOCK) \
+    (glthread_recursive_lock_init_func (LOCK), 0)
+# define glthread_recursive_lock_lock(LOCK) \
+    glthread_recursive_lock_lock_func (LOCK)
+# define glthread_recursive_lock_unlock(LOCK) \
+    glthread_recursive_lock_unlock_func (LOCK)
+# define glthread_recursive_lock_destroy(LOCK) \
+    glthread_recursive_lock_destroy_func (LOCK)
+extern void glthread_recursive_lock_init_func (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock);
+extern int glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock);
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+typedef struct
+        {
+          volatile int inited;
+          volatile long started;
+          CRITICAL_SECTION lock;
+        }
+        gl_once_t;
+# define gl_once_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_once_t NAME = { -1, -1 };
+# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
+    (glthread_once_func (ONCE_CONTROL, INITFUNCTION), 0)
+extern void glthread_once_func (gl_once_t *once_control, void (*initfunction) (void));
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+#if !(USE_POSIX_THREADS || USE_PTH_THREADS || USE_SOLARIS_THREADS || USE_WINDOWS_THREADS)
+
+/* Provide dummy implementation if threads are not supported.  */
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+typedef int gl_lock_t;
+# define gl_lock_define(STORAGECLASS, NAME)
+# define gl_lock_define_initialized(STORAGECLASS, NAME)
+# define glthread_lock_init(NAME) 0
+# define glthread_lock_lock(NAME) 0
+# define glthread_lock_unlock(NAME) 0
+# define glthread_lock_destroy(NAME) 0
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+typedef int gl_rwlock_t;
+# define gl_rwlock_define(STORAGECLASS, NAME)
+# define gl_rwlock_define_initialized(STORAGECLASS, NAME)
+# define glthread_rwlock_init(NAME) 0
+# define glthread_rwlock_rdlock(NAME) 0
+# define glthread_rwlock_wrlock(NAME) 0
+# define glthread_rwlock_unlock(NAME) 0
+# define glthread_rwlock_destroy(NAME) 0
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+typedef int gl_recursive_lock_t;
+# define gl_recursive_lock_define(STORAGECLASS, NAME)
+# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME)
+# define glthread_recursive_lock_init(NAME) 0
+# define glthread_recursive_lock_lock(NAME) 0
+# define glthread_recursive_lock_unlock(NAME) 0
+# define glthread_recursive_lock_destroy(NAME) 0
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+typedef int gl_once_t;
+# define gl_once_define(STORAGECLASS, NAME) \
+    STORAGECLASS gl_once_t NAME = 0;
+# define glthread_once(ONCE_CONTROL, INITFUNCTION) \
+    (*(ONCE_CONTROL) == 0 ? (*(ONCE_CONTROL) = ~ 0, INITFUNCTION (), 0) : 0)
+
+#endif
+
+/* ========================================================================= */
+
+/* Macros with built-in error handling.  */
+
+/* -------------------------- gl_lock_t datatype -------------------------- */
+
+#define gl_lock_init(NAME) \
+   do                                  \
+     {                                 \
+       if (glthread_lock_init (&NAME)) \
+         abort ();                     \
+     }                                 \
+   while (0)
+#define gl_lock_lock(NAME) \
+   do                                  \
+     {                                 \
+       if (glthread_lock_lock (&NAME)) \
+         abort ();                     \
+     }                                 \
+   while (0)
+#define gl_lock_unlock(NAME) \
+   do                                    \
+     {                                   \
+       if (glthread_lock_unlock (&NAME)) \
+         abort ();                       \
+     }                                   \
+   while (0)
+#define gl_lock_destroy(NAME) \
+   do                                     \
+     {                                    \
+       if (glthread_lock_destroy (&NAME)) \
+         abort ();                        \
+     }                                    \
+   while (0)
+
+/* ------------------------- gl_rwlock_t datatype ------------------------- */
+
+#define gl_rwlock_init(NAME) \
+   do                                    \
+     {                                   \
+       if (glthread_rwlock_init (&NAME)) \
+         abort ();                       \
+     }                                   \
+   while (0)
+#define gl_rwlock_rdlock(NAME) \
+   do                                      \
+     {                                     \
+       if (glthread_rwlock_rdlock (&NAME)) \
+         abort ();                         \
+     }                                     \
+   while (0)
+#define gl_rwlock_wrlock(NAME) \
+   do                                      \
+     {                                     \
+       if (glthread_rwlock_wrlock (&NAME)) \
+         abort ();                         \
+     }                                     \
+   while (0)
+#define gl_rwlock_unlock(NAME) \
+   do                                      \
+     {                                     \
+       if (glthread_rwlock_unlock (&NAME)) \
+         abort ();                         \
+     }                                     \
+   while (0)
+#define gl_rwlock_destroy(NAME) \
+   do                                       \
+     {                                      \
+       if (glthread_rwlock_destroy (&NAME)) \
+         abort ();                          \
+     }                                      \
+   while (0)
+
+/* --------------------- gl_recursive_lock_t datatype --------------------- */
+
+#define gl_recursive_lock_init(NAME) \
+   do                                            \
+     {                                           \
+       if (glthread_recursive_lock_init (&NAME)) \
+         abort ();                               \
+     }                                           \
+   while (0)
+#define gl_recursive_lock_lock(NAME) \
+   do                                            \
+     {                                           \
+       if (glthread_recursive_lock_lock (&NAME)) \
+         abort ();                               \
+     }                                           \
+   while (0)
+#define gl_recursive_lock_unlock(NAME) \
+   do                                              \
+     {                                             \
+       if (glthread_recursive_lock_unlock (&NAME)) \
+         abort ();                                 \
+     }                                             \
+   while (0)
+#define gl_recursive_lock_destroy(NAME) \
+   do                                               \
+     {                                              \
+       if (glthread_recursive_lock_destroy (&NAME)) \
+         abort ();                                  \
+     }                                              \
+   while (0)
+
+/* -------------------------- gl_once_t datatype -------------------------- */
+
+#define gl_once(NAME, INITFUNCTION) \
+   do                                           \
+     {                                          \
+       if (glthread_once (&NAME, INITFUNCTION)) \
+         abort ();                              \
+     }                                          \
+   while (0)
+
+/* ========================================================================= */
+
+#endif /* _LOCK_H */
diff --git a/gnulib/import/glthread/threadlib.c b/gnulib/import/glthread/threadlib.c
new file mode 100644
index 0000000..be63713
--- /dev/null
+++ b/gnulib/import/glthread/threadlib.c
@@ -0,0 +1,73 @@ 
+/* Multithreading primitives.
+   Copyright (C) 2005-2016 Free Software Foundation, Inc.
+
+   This program 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, or (at your option)
+   any later version.
+
+   This program 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 program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005.  */
+
+#include <config.h>
+
+/* ========================================================================= */
+
+#if USE_POSIX_THREADS
+
+/* Use the POSIX threads library.  */
+
+# include <pthread.h>
+# include <stdlib.h>
+
+# if PTHREAD_IN_USE_DETECTION_HARD
+
+/* The function to be executed by a dummy thread.  */
+static void *
+dummy_thread_func (void *arg)
+{
+  return arg;
+}
+
+int
+glthread_in_use (void)
+{
+  static int tested;
+  static int result; /* 1: linked with -lpthread, 0: only with libc */
+
+  if (!tested)
+    {
+      pthread_t thread;
+
+      if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0)
+        /* Thread creation failed.  */
+        result = 0;
+      else
+        {
+          /* Thread creation works.  */
+          void *retval;
+          if (pthread_join (thread, &retval) != 0)
+            abort ();
+          result = 1;
+        }
+      tested = 1;
+    }
+  return result;
+}
+
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;
diff --git a/gnulib/import/m4/gnulib-cache.m4 b/gnulib/import/m4/gnulib-cache.m4
index 4cbd1a7..6dbb6b8 100644
--- a/gnulib/import/m4/gnulib-cache.m4
+++ b/gnulib/import/m4/gnulib-cache.m4
@@ -27,7 +27,7 @@ 
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
+#   gnulib-tool --import --lib=libgnu --source-base=import --m4-base=import/m4 --doc-base=doc --tests-base=tests --aux-dir=import/extra --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca canonicalize-lgpl dirent dirfd errno fnmatch-gnu frexpl getcwd glob inet_ntop inttypes limits-h lstat memchr memmem mkdir mkdtemp mkostemp pathmax rawmemchr readlink rename setenv signal-h strchrnul strerror_r-posix strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])
@@ -57,6 +57,7 @@ 
   setenv
   signal-h
   strchrnul
+  strerror_r-posix
   strstr
   strtok_r
   sys_stat
diff --git a/gnulib/import/m4/gnulib-comp.m4 b/gnulib/import/m4/gnulib-comp.m4
index 1700bdd..fdfc206 100644
--- a/gnulib/import/m4/gnulib-comp.m4
+++ b/gnulib/import/m4/gnulib-comp.m4
@@ -42,6 +42,7 @@ 
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_REQUIRE([gl_PROG_AR_RANLIB])
 
+  AC_REQUIRE([AM_PROG_CC_C_O])
   # Code from module absolute-header:
   # Code from module alloca:
   # Code from module alloca-opt:
@@ -97,6 +98,7 @@ 
   # Code from module gettimeofday:
   # Code from module glob:
   # Code from module hard-locale:
+  # Code from module havelib:
   # Code from module include_next:
   # Code from module inet_ntop:
   # Code from module intprops:
@@ -108,6 +110,7 @@ 
   AC_REQUIRE([AC_SYS_LARGEFILE])
   # Code from module limits-h:
   # Code from module localcharset:
+  # Code from module lock:
   # Code from module lstat:
   # Code from module malloc-posix:
   # Code from module malloca:
@@ -164,6 +167,7 @@ 
   # Code from module streq:
   # Code from module strerror:
   # Code from module strerror-override:
+  # Code from module strerror_r-posix:
   # Code from module string:
   # Code from module strnlen1:
   # Code from module strstr:
@@ -175,6 +179,8 @@ 
   # Code from module sys_types:
   # Code from module sys_uio:
   # Code from module tempname:
+  # Code from module threadlib:
+  gl_THREADLIB_EARLY
   # Code from module time:
   # Code from module unistd:
   # Code from module unistd-safer:
@@ -382,6 +388,8 @@ 
   gl_LOCALCHARSET
   LOCALCHARSET_TESTS_ENVIRONMENT="CHARSETALIASDIR=\"\$(abs_top_builddir)/$gl_source_base\""
   AC_SUBST([LOCALCHARSET_TESTS_ENVIRONMENT])
+  gl_LOCK
+  gl_MODULE_INDICATOR([lock])
   gl_FUNC_LSTAT
   if test $REPLACE_LSTAT = 1; then
     AC_LIBOBJ([lstat])
@@ -576,6 +584,12 @@ 
     AC_LIBOBJ([strerror-override])
     gl_PREREQ_SYS_H_WINSOCK2
   fi
+  gl_FUNC_STRERROR_R
+  if test $HAVE_DECL_STRERROR_R = 0 || test $REPLACE_STRERROR_R = 1; then
+    AC_LIBOBJ([strerror_r])
+    gl_PREREQ_STRERROR_R
+  fi
+  gl_STRING_MODULE_INDICATOR([strerror_r])
   gl_HEADER_STRING_H
   gl_FUNC_STRSTR
   if test $REPLACE_STRSTR = 1; then
@@ -603,6 +617,7 @@ 
   gl_HEADER_SYS_UIO
   AC_PROG_MKDIR_P
   gl_FUNC_GEN_TEMPNAME
+  gl_THREADLIB
   gl_HEADER_TIME_H
   gl_UNISTD_H
   gl_UNISTD_SAFER
@@ -754,6 +769,7 @@ 
 # This macro records the list of files which have been installed by
 # gnulib-tool and may be removed by future gnulib-tool invocations.
 AC_DEFUN([gl_FILE_LIST], [
+  build-aux/config.rpath
   build-aux/snippet/_Noreturn.h
   build-aux/snippet/arg-nonnull.h
   build-aux/snippet/c++defs.h
@@ -820,6 +836,9 @@ 
   lib/glob-libc.h
   lib/glob.c
   lib/glob.in.h
+  lib/glthread/lock.c
+  lib/glthread/lock.h
+  lib/glthread/threadlib.c
   lib/hard-locale.c
   lib/hard-locale.h
   lib/inet_ntop.c
@@ -899,6 +918,7 @@ 
   lib/strerror-override.c
   lib/strerror-override.h
   lib/strerror.c
+  lib/strerror_r.c
   lib/string.in.h
   lib/stripslash.c
   lib/strnlen1.c
@@ -981,11 +1001,15 @@ 
   m4/isnand.m4
   m4/isnanl.m4
   m4/largefile.m4
+  m4/lib-ld.m4
+  m4/lib-link.m4
+  m4/lib-prefix.m4
   m4/limits-h.m4
   m4/localcharset.m4
   m4/locale-fr.m4
   m4/locale-ja.m4
   m4/locale-zh.m4
+  m4/lock.m4
   m4/longlong.m4
   m4/lstat.m4
   m4/malloc.m4
@@ -1039,6 +1063,7 @@ 
   m4/strchrnul.m4
   m4/strdup.m4
   m4/strerror.m4
+  m4/strerror_r.m4
   m4/string_h.m4
   m4/strstr.m4
   m4/strtok_r.m4
@@ -1048,6 +1073,7 @@ 
   m4/sys_types_h.m4
   m4/sys_uio_h.m4
   m4/tempname.m4
+  m4/threadlib.m4
   m4/time_h.m4
   m4/unistd-safer.m4
   m4/unistd_h.m4
diff --git a/gnulib/import/m4/lib-ld.m4 b/gnulib/import/m4/lib-ld.m4
new file mode 100644
index 0000000..6209de6
--- /dev/null
+++ b/gnulib/import/m4/lib-ld.m4
@@ -0,0 +1,119 @@ 
+# lib-ld.m4 serial 6
+dnl Copyright (C) 1996-2003, 2009-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Subroutines of libtool.m4,
+dnl with replacements s/_*LT_PATH/AC_LIB_PROG/ and s/lt_/acl_/ to avoid
+dnl collision with libtool.m4.
+
+dnl From libtool-2.4. Sets the variable with_gnu_ld to yes or no.
+AC_DEFUN([AC_LIB_PROG_LD_GNU],
+[AC_CACHE_CHECK([if the linker ($LD) is GNU ld], [acl_cv_prog_gnu_ld],
+[# I'd rather use --version here, but apparently some GNU lds only accept -v.
+case `$LD -v 2>&1 </dev/null` in
+*GNU* | *'with BFD'*)
+  acl_cv_prog_gnu_ld=yes
+  ;;
+*)
+  acl_cv_prog_gnu_ld=no
+  ;;
+esac])
+with_gnu_ld=$acl_cv_prog_gnu_ld
+])
+
+dnl From libtool-2.4. Sets the variable LD.
+AC_DEFUN([AC_LIB_PROG_LD],
+[AC_REQUIRE([AC_PROG_CC])dnl
+AC_REQUIRE([AC_CANONICAL_HOST])dnl
+
+AC_ARG_WITH([gnu-ld],
+    [AS_HELP_STRING([--with-gnu-ld],
+        [assume the C compiler uses GNU ld [default=no]])],
+    [test "$withval" = no || with_gnu_ld=yes],
+    [with_gnu_ld=no])dnl
+
+# Prepare PATH_SEPARATOR.
+# The user is always right.
+if test "${PATH_SEPARATOR+set}" != set; then
+  # Determine PATH_SEPARATOR by trying to find /bin/sh in a PATH which
+  # contains only /bin. Note that ksh looks also at the FPATH variable,
+  # so we have to set that as well for the test.
+  PATH_SEPARATOR=:
+  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+    && { (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+           || PATH_SEPARATOR=';'
+       }
+fi
+
+ac_prog=ld
+if test "$GCC" = yes; then
+  # Check if gcc -print-prog-name=ld gives a path.
+  AC_MSG_CHECKING([for ld used by $CC])
+  case $host in
+  *-*-mingw*)
+    # gcc leaves a trailing carriage return which upsets mingw
+    ac_prog=`($CC -print-prog-name=ld) 2>&5 | tr -d '\015'` ;;
+  *)
+    ac_prog=`($CC -print-prog-name=ld) 2>&5` ;;
+  esac
+  case $ac_prog in
+    # Accept absolute paths.
+    [[\\/]]* | ?:[[\\/]]*)
+      re_direlt='/[[^/]][[^/]]*/\.\./'
+      # Canonicalize the pathname of ld
+      ac_prog=`echo "$ac_prog"| sed 's%\\\\%/%g'`
+      while echo "$ac_prog" | grep "$re_direlt" > /dev/null 2>&1; do
+        ac_prog=`echo $ac_prog| sed "s%$re_direlt%/%"`
+      done
+      test -z "$LD" && LD="$ac_prog"
+      ;;
+  "")
+    # If it fails, then pretend we aren't using GCC.
+    ac_prog=ld
+    ;;
+  *)
+    # If it is relative, then search for the first ld in PATH.
+    with_gnu_ld=unknown
+    ;;
+  esac
+elif test "$with_gnu_ld" = yes; then
+  AC_MSG_CHECKING([for GNU ld])
+else
+  AC_MSG_CHECKING([for non-GNU ld])
+fi
+AC_CACHE_VAL([acl_cv_path_LD],
+[if test -z "$LD"; then
+  acl_save_ifs="$IFS"; IFS=$PATH_SEPARATOR
+  for ac_dir in $PATH; do
+    IFS="$acl_save_ifs"
+    test -z "$ac_dir" && ac_dir=.
+    if test -f "$ac_dir/$ac_prog" || test -f "$ac_dir/$ac_prog$ac_exeext"; then
+      acl_cv_path_LD="$ac_dir/$ac_prog"
+      # Check to see if the program is GNU ld.  I'd rather use --version,
+      # but apparently some variants of GNU ld only accept -v.
+      # Break only if it was the GNU/non-GNU ld that we prefer.
+      case `"$acl_cv_path_LD" -v 2>&1 </dev/null` in
+      *GNU* | *'with BFD'*)
+        test "$with_gnu_ld" != no && break
+        ;;
+      *)
+        test "$with_gnu_ld" != yes && break
+        ;;
+      esac
+    fi
+  done
+  IFS="$acl_save_ifs"
+else
+  acl_cv_path_LD="$LD" # Let the user override the test with a path.
+fi])
+LD="$acl_cv_path_LD"
+if test -n "$LD"; then
+  AC_MSG_RESULT([$LD])
+else
+  AC_MSG_RESULT([no])
+fi
+test -z "$LD" && AC_MSG_ERROR([no acceptable ld found in \$PATH])
+AC_LIB_PROG_LD_GNU
+])
diff --git a/gnulib/import/m4/lib-link.m4 b/gnulib/import/m4/lib-link.m4
new file mode 100644
index 0000000..2f51855
--- /dev/null
+++ b/gnulib/import/m4/lib-link.m4
@@ -0,0 +1,777 @@ 
+# lib-link.m4 serial 26 (gettext-0.18.2)
+dnl Copyright (C) 2001-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+AC_PREREQ([2.54])
+
+dnl AC_LIB_LINKFLAGS(name [, dependencies]) searches for libname and
+dnl the libraries corresponding to explicit and implicit dependencies.
+dnl Sets and AC_SUBSTs the LIB${NAME} and LTLIB${NAME} variables and
+dnl augments the CPPFLAGS variable.
+dnl Sets and AC_SUBSTs the LIB${NAME}_PREFIX variable to nonempty if libname
+dnl was found in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
+AC_DEFUN([AC_LIB_LINKFLAGS],
+[
+  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
+  AC_REQUIRE([AC_LIB_RPATH])
+  pushdef([Name],[m4_translit([$1],[./+-], [____])])
+  pushdef([NAME],[m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./+-],
+                                   [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+  AC_CACHE_CHECK([how to link with lib[]$1], [ac_cv_lib[]Name[]_libs], [
+    AC_LIB_LINKFLAGS_BODY([$1], [$2])
+    ac_cv_lib[]Name[]_libs="$LIB[]NAME"
+    ac_cv_lib[]Name[]_ltlibs="$LTLIB[]NAME"
+    ac_cv_lib[]Name[]_cppflags="$INC[]NAME"
+    ac_cv_lib[]Name[]_prefix="$LIB[]NAME[]_PREFIX"
+  ])
+  LIB[]NAME="$ac_cv_lib[]Name[]_libs"
+  LTLIB[]NAME="$ac_cv_lib[]Name[]_ltlibs"
+  INC[]NAME="$ac_cv_lib[]Name[]_cppflags"
+  LIB[]NAME[]_PREFIX="$ac_cv_lib[]Name[]_prefix"
+  AC_LIB_APPENDTOVAR([CPPFLAGS], [$INC]NAME)
+  AC_SUBST([LIB]NAME)
+  AC_SUBST([LTLIB]NAME)
+  AC_SUBST([LIB]NAME[_PREFIX])
+  dnl Also set HAVE_LIB[]NAME so that AC_LIB_HAVE_LINKFLAGS can reuse the
+  dnl results of this search when this library appears as a dependency.
+  HAVE_LIB[]NAME=yes
+  popdef([NAME])
+  popdef([Name])
+])
+
+dnl AC_LIB_HAVE_LINKFLAGS(name, dependencies, includes, testcode, [missing-message])
+dnl searches for libname and the libraries corresponding to explicit and
+dnl implicit dependencies, together with the specified include files and
+dnl the ability to compile and link the specified testcode. The missing-message
+dnl defaults to 'no' and may contain additional hints for the user.
+dnl If found, it sets and AC_SUBSTs HAVE_LIB${NAME}=yes and the LIB${NAME}
+dnl and LTLIB${NAME} variables and augments the CPPFLAGS variable, and
+dnl #defines HAVE_LIB${NAME} to 1. Otherwise, it sets and AC_SUBSTs
+dnl HAVE_LIB${NAME}=no and LIB${NAME} and LTLIB${NAME} to empty.
+dnl Sets and AC_SUBSTs the LIB${NAME}_PREFIX variable to nonempty if libname
+dnl was found in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
+AC_DEFUN([AC_LIB_HAVE_LINKFLAGS],
+[
+  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
+  AC_REQUIRE([AC_LIB_RPATH])
+  pushdef([Name],[m4_translit([$1],[./+-], [____])])
+  pushdef([NAME],[m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./+-],
+                                   [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+
+  dnl Search for lib[]Name and define LIB[]NAME, LTLIB[]NAME and INC[]NAME
+  dnl accordingly.
+  AC_LIB_LINKFLAGS_BODY([$1], [$2])
+
+  dnl Add $INC[]NAME to CPPFLAGS before performing the following checks,
+  dnl because if the user has installed lib[]Name and not disabled its use
+  dnl via --without-lib[]Name-prefix, he wants to use it.
+  ac_save_CPPFLAGS="$CPPFLAGS"
+  AC_LIB_APPENDTOVAR([CPPFLAGS], [$INC]NAME)
+
+  AC_CACHE_CHECK([for lib[]$1], [ac_cv_lib[]Name], [
+    ac_save_LIBS="$LIBS"
+    dnl If $LIB[]NAME contains some -l options, add it to the end of LIBS,
+    dnl because these -l options might require -L options that are present in
+    dnl LIBS. -l options benefit only from the -L options listed before it.
+    dnl Otherwise, add it to the front of LIBS, because it may be a static
+    dnl library that depends on another static library that is present in LIBS.
+    dnl Static libraries benefit only from the static libraries listed after
+    dnl it.
+    case " $LIB[]NAME" in
+      *" -l"*) LIBS="$LIBS $LIB[]NAME" ;;
+      *)       LIBS="$LIB[]NAME $LIBS" ;;
+    esac
+    AC_LINK_IFELSE(
+      [AC_LANG_PROGRAM([[$3]], [[$4]])],
+      [ac_cv_lib[]Name=yes],
+      [ac_cv_lib[]Name='m4_if([$5], [], [no], [[$5]])'])
+    LIBS="$ac_save_LIBS"
+  ])
+  if test "$ac_cv_lib[]Name" = yes; then
+    HAVE_LIB[]NAME=yes
+    AC_DEFINE([HAVE_LIB]NAME, 1, [Define if you have the lib][$1 library.])
+    AC_MSG_CHECKING([how to link with lib[]$1])
+    AC_MSG_RESULT([$LIB[]NAME])
+  else
+    HAVE_LIB[]NAME=no
+    dnl If $LIB[]NAME didn't lead to a usable library, we don't need
+    dnl $INC[]NAME either.
+    CPPFLAGS="$ac_save_CPPFLAGS"
+    LIB[]NAME=
+    LTLIB[]NAME=
+    LIB[]NAME[]_PREFIX=
+  fi
+  AC_SUBST([HAVE_LIB]NAME)
+  AC_SUBST([LIB]NAME)
+  AC_SUBST([LTLIB]NAME)
+  AC_SUBST([LIB]NAME[_PREFIX])
+  popdef([NAME])
+  popdef([Name])
+])
+
+dnl Determine the platform dependent parameters needed to use rpath:
+dnl   acl_libext,
+dnl   acl_shlibext,
+dnl   acl_libname_spec,
+dnl   acl_library_names_spec,
+dnl   acl_hardcode_libdir_flag_spec,
+dnl   acl_hardcode_libdir_separator,
+dnl   acl_hardcode_direct,
+dnl   acl_hardcode_minus_L.
+AC_DEFUN([AC_LIB_RPATH],
+[
+  dnl Tell automake >= 1.10 to complain if config.rpath is missing.
+  m4_ifdef([AC_REQUIRE_AUX_FILE], [AC_REQUIRE_AUX_FILE([config.rpath])])
+  AC_REQUIRE([AC_PROG_CC])                dnl we use $CC, $GCC, $LDFLAGS
+  AC_REQUIRE([AC_LIB_PROG_LD])            dnl we use $LD, $with_gnu_ld
+  AC_REQUIRE([AC_CANONICAL_HOST])         dnl we use $host
+  AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT]) dnl we use $ac_aux_dir
+  AC_CACHE_CHECK([for shared library run path origin], [acl_cv_rpath], [
+    CC="$CC" GCC="$GCC" LDFLAGS="$LDFLAGS" LD="$LD" with_gnu_ld="$with_gnu_ld" \
+    ${CONFIG_SHELL-/bin/sh} "$ac_aux_dir/config.rpath" "$host" > conftest.sh
+    . ./conftest.sh
+    rm -f ./conftest.sh
+    acl_cv_rpath=done
+  ])
+  wl="$acl_cv_wl"
+  acl_libext="$acl_cv_libext"
+  acl_shlibext="$acl_cv_shlibext"
+  acl_libname_spec="$acl_cv_libname_spec"
+  acl_library_names_spec="$acl_cv_library_names_spec"
+  acl_hardcode_libdir_flag_spec="$acl_cv_hardcode_libdir_flag_spec"
+  acl_hardcode_libdir_separator="$acl_cv_hardcode_libdir_separator"
+  acl_hardcode_direct="$acl_cv_hardcode_direct"
+  acl_hardcode_minus_L="$acl_cv_hardcode_minus_L"
+  dnl Determine whether the user wants rpath handling at all.
+  AC_ARG_ENABLE([rpath],
+    [  --disable-rpath         do not hardcode runtime library paths],
+    :, enable_rpath=yes)
+])
+
+dnl AC_LIB_FROMPACKAGE(name, package)
+dnl declares that libname comes from the given package. The configure file
+dnl will then not have a --with-libname-prefix option but a
+dnl --with-package-prefix option. Several libraries can come from the same
+dnl package. This declaration must occur before an AC_LIB_LINKFLAGS or similar
+dnl macro call that searches for libname.
+AC_DEFUN([AC_LIB_FROMPACKAGE],
+[
+  pushdef([NAME],[m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./+-],
+                                   [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+  define([acl_frompackage_]NAME, [$2])
+  popdef([NAME])
+  pushdef([PACK],[$2])
+  pushdef([PACKUP],[m4_translit(PACK,[abcdefghijklmnopqrstuvwxyz./+-],
+                                     [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+  define([acl_libsinpackage_]PACKUP,
+    m4_ifdef([acl_libsinpackage_]PACKUP, [m4_defn([acl_libsinpackage_]PACKUP)[, ]],)[lib$1])
+  popdef([PACKUP])
+  popdef([PACK])
+])
+
+dnl AC_LIB_LINKFLAGS_BODY(name [, dependencies]) searches for libname and
+dnl the libraries corresponding to explicit and implicit dependencies.
+dnl Sets the LIB${NAME}, LTLIB${NAME} and INC${NAME} variables.
+dnl Also, sets the LIB${NAME}_PREFIX variable to nonempty if libname was found
+dnl in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
+AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
+[
+  AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])
+  pushdef([NAME],[m4_translit([$1],[abcdefghijklmnopqrstuvwxyz./+-],
+                                   [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+  pushdef([PACK],[m4_ifdef([acl_frompackage_]NAME, [acl_frompackage_]NAME, lib[$1])])
+  pushdef([PACKUP],[m4_translit(PACK,[abcdefghijklmnopqrstuvwxyz./+-],
+                                     [ABCDEFGHIJKLMNOPQRSTUVWXYZ____])])
+  pushdef([PACKLIBS],[m4_ifdef([acl_frompackage_]NAME, [acl_libsinpackage_]PACKUP, lib[$1])])
+  dnl Autoconf >= 2.61 supports dots in --with options.
+  pushdef([P_A_C_K],[m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]),[2.61]),[-1],[m4_translit(PACK,[.],[_])],PACK)])
+  dnl By default, look in $includedir and $libdir.
+  use_additional=yes
+  AC_LIB_WITH_FINAL_PREFIX([
+    eval additional_includedir=\"$includedir\"
+    eval additional_libdir=\"$libdir\"
+  ])
+  AC_ARG_WITH(P_A_C_K[-prefix],
+[[  --with-]]P_A_C_K[[-prefix[=DIR]  search for ]PACKLIBS[ in DIR/include and DIR/lib
+  --without-]]P_A_C_K[[-prefix     don't search for ]PACKLIBS[ in includedir and libdir]],
+[
+    if test "X$withval" = "Xno"; then
+      use_additional=no
+    else
+      if test "X$withval" = "X"; then
+        AC_LIB_WITH_FINAL_PREFIX([
+          eval additional_includedir=\"$includedir\"
+          eval additional_libdir=\"$libdir\"
+        ])
+      else
+        additional_includedir="$withval/include"
+        additional_libdir="$withval/$acl_libdirstem"
+        if test "$acl_libdirstem2" != "$acl_libdirstem" \
+           && ! test -d "$withval/$acl_libdirstem"; then
+          additional_libdir="$withval/$acl_libdirstem2"
+        fi
+      fi
+    fi
+])
+  dnl Search the library and its dependencies in $additional_libdir and
+  dnl $LDFLAGS. Using breadth-first-seach.
+  LIB[]NAME=
+  LTLIB[]NAME=
+  INC[]NAME=
+  LIB[]NAME[]_PREFIX=
+  dnl HAVE_LIB${NAME} is an indicator that LIB${NAME}, LTLIB${NAME} have been
+  dnl computed. So it has to be reset here.
+  HAVE_LIB[]NAME=
+  rpathdirs=
+  ltrpathdirs=
+  names_already_handled=
+  names_next_round='$1 $2'
+  while test -n "$names_next_round"; do
+    names_this_round="$names_next_round"
+    names_next_round=
+    for name in $names_this_round; do
+      already_handled=
+      for n in $names_already_handled; do
+        if test "$n" = "$name"; then
+          already_handled=yes
+          break
+        fi
+      done
+      if test -z "$already_handled"; then
+        names_already_handled="$names_already_handled $name"
+        dnl See if it was already located by an earlier AC_LIB_LINKFLAGS
+        dnl or AC_LIB_HAVE_LINKFLAGS call.
+        uppername=`echo "$name" | sed -e 'y|abcdefghijklmnopqrstuvwxyz./+-|ABCDEFGHIJKLMNOPQRSTUVWXYZ____|'`
+        eval value=\"\$HAVE_LIB$uppername\"
+        if test -n "$value"; then
+          if test "$value" = yes; then
+            eval value=\"\$LIB$uppername\"
+            test -z "$value" || LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$value"
+            eval value=\"\$LTLIB$uppername\"
+            test -z "$value" || LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$value"
+          else
+            dnl An earlier call to AC_LIB_HAVE_LINKFLAGS has determined
+            dnl that this library doesn't exist. So just drop it.
+            :
+          fi
+        else
+          dnl Search the library lib$name in $additional_libdir and $LDFLAGS
+          dnl and the already constructed $LIBNAME/$LTLIBNAME.
+          found_dir=
+          found_la=
+          found_so=
+          found_a=
+          eval libname=\"$acl_libname_spec\"    # typically: libname=lib$name
+          if test -n "$acl_shlibext"; then
+            shrext=".$acl_shlibext"             # typically: shrext=.so
+          else
+            shrext=
+          fi
+          if test $use_additional = yes; then
+            dir="$additional_libdir"
+            dnl The same code as in the loop below:
+            dnl First look for a shared library.
+            if test -n "$acl_shlibext"; then
+              if test -f "$dir/$libname$shrext"; then
+                found_dir="$dir"
+                found_so="$dir/$libname$shrext"
+              else
+                if test "$acl_library_names_spec" = '$libname$shrext$versuffix'; then
+                  ver=`(cd "$dir" && \
+                        for f in "$libname$shrext".*; do echo "$f"; done \
+                        | sed -e "s,^$libname$shrext\\\\.,," \
+                        | sort -t '.' -n -r -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 \
+                        | sed 1q ) 2>/dev/null`
+                  if test -n "$ver" && test -f "$dir/$libname$shrext.$ver"; then
+                    found_dir="$dir"
+                    found_so="$dir/$libname$shrext.$ver"
+                  fi
+                else
+                  eval library_names=\"$acl_library_names_spec\"
+                  for f in $library_names; do
+                    if test -f "$dir/$f"; then
+                      found_dir="$dir"
+                      found_so="$dir/$f"
+                      break
+                    fi
+                  done
+                fi
+              fi
+            fi
+            dnl Then look for a static library.
+            if test "X$found_dir" = "X"; then
+              if test -f "$dir/$libname.$acl_libext"; then
+                found_dir="$dir"
+                found_a="$dir/$libname.$acl_libext"
+              fi
+            fi
+            if test "X$found_dir" != "X"; then
+              if test -f "$dir/$libname.la"; then
+                found_la="$dir/$libname.la"
+              fi
+            fi
+          fi
+          if test "X$found_dir" = "X"; then
+            for x in $LDFLAGS $LTLIB[]NAME; do
+              AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+              case "$x" in
+                -L*)
+                  dir=`echo "X$x" | sed -e 's/^X-L//'`
+                  dnl First look for a shared library.
+                  if test -n "$acl_shlibext"; then
+                    if test -f "$dir/$libname$shrext"; then
+                      found_dir="$dir"
+                      found_so="$dir/$libname$shrext"
+                    else
+                      if test "$acl_library_names_spec" = '$libname$shrext$versuffix'; then
+                        ver=`(cd "$dir" && \
+                              for f in "$libname$shrext".*; do echo "$f"; done \
+                              | sed -e "s,^$libname$shrext\\\\.,," \
+                              | sort -t '.' -n -r -k1,1 -k2,2 -k3,3 -k4,4 -k5,5 \
+                              | sed 1q ) 2>/dev/null`
+                        if test -n "$ver" && test -f "$dir/$libname$shrext.$ver"; then
+                          found_dir="$dir"
+                          found_so="$dir/$libname$shrext.$ver"
+                        fi
+                      else
+                        eval library_names=\"$acl_library_names_spec\"
+                        for f in $library_names; do
+                          if test -f "$dir/$f"; then
+                            found_dir="$dir"
+                            found_so="$dir/$f"
+                            break
+                          fi
+                        done
+                      fi
+                    fi
+                  fi
+                  dnl Then look for a static library.
+                  if test "X$found_dir" = "X"; then
+                    if test -f "$dir/$libname.$acl_libext"; then
+                      found_dir="$dir"
+                      found_a="$dir/$libname.$acl_libext"
+                    fi
+                  fi
+                  if test "X$found_dir" != "X"; then
+                    if test -f "$dir/$libname.la"; then
+                      found_la="$dir/$libname.la"
+                    fi
+                  fi
+                  ;;
+              esac
+              if test "X$found_dir" != "X"; then
+                break
+              fi
+            done
+          fi
+          if test "X$found_dir" != "X"; then
+            dnl Found the library.
+            LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$found_dir -l$name"
+            if test "X$found_so" != "X"; then
+              dnl Linking with a shared library. We attempt to hardcode its
+              dnl directory into the executable's runpath, unless it's the
+              dnl standard /usr/lib.
+              if test "$enable_rpath" = no \
+                 || test "X$found_dir" = "X/usr/$acl_libdirstem" \
+                 || test "X$found_dir" = "X/usr/$acl_libdirstem2"; then
+                dnl No hardcoding is needed.
+                LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
+              else
+                dnl Use an explicit option to hardcode DIR into the resulting
+                dnl binary.
+                dnl Potentially add DIR to ltrpathdirs.
+                dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
+                haveit=
+                for x in $ltrpathdirs; do
+                  if test "X$x" = "X$found_dir"; then
+                    haveit=yes
+                    break
+                  fi
+                done
+                if test -z "$haveit"; then
+                  ltrpathdirs="$ltrpathdirs $found_dir"
+                fi
+                dnl The hardcoding into $LIBNAME is system dependent.
+                if test "$acl_hardcode_direct" = yes; then
+                  dnl Using DIR/libNAME.so during linking hardcodes DIR into the
+                  dnl resulting binary.
+                  LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
+                else
+                  if test -n "$acl_hardcode_libdir_flag_spec" && test "$acl_hardcode_minus_L" = no; then
+                    dnl Use an explicit option to hardcode DIR into the resulting
+                    dnl binary.
+                    LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
+                    dnl Potentially add DIR to rpathdirs.
+                    dnl The rpathdirs will be appended to $LIBNAME at the end.
+                    haveit=
+                    for x in $rpathdirs; do
+                      if test "X$x" = "X$found_dir"; then
+                        haveit=yes
+                        break
+                      fi
+                    done
+                    if test -z "$haveit"; then
+                      rpathdirs="$rpathdirs $found_dir"
+                    fi
+                  else
+                    dnl Rely on "-L$found_dir".
+                    dnl But don't add it if it's already contained in the LDFLAGS
+                    dnl or the already constructed $LIBNAME
+                    haveit=
+                    for x in $LDFLAGS $LIB[]NAME; do
+                      AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+                      if test "X$x" = "X-L$found_dir"; then
+                        haveit=yes
+                        break
+                      fi
+                    done
+                    if test -z "$haveit"; then
+                      LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir"
+                    fi
+                    if test "$acl_hardcode_minus_L" != no; then
+                      dnl FIXME: Not sure whether we should use
+                      dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
+                      dnl here.
+                      LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
+                    else
+                      dnl We cannot use $acl_hardcode_runpath_var and LD_RUN_PATH
+                      dnl here, because this doesn't fit in flags passed to the
+                      dnl compiler. So give up. No hardcoding. This affects only
+                      dnl very old systems.
+                      dnl FIXME: Not sure whether we should use
+                      dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
+                      dnl here.
+                      LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
+                    fi
+                  fi
+                fi
+              fi
+            else
+              if test "X$found_a" != "X"; then
+                dnl Linking with a static library.
+                LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_a"
+              else
+                dnl We shouldn't come here, but anyway it's good to have a
+                dnl fallback.
+                LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir -l$name"
+              fi
+            fi
+            dnl Assume the include files are nearby.
+            additional_includedir=
+            case "$found_dir" in
+              */$acl_libdirstem | */$acl_libdirstem/)
+                basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e "s,/$acl_libdirstem/"'*$,,'`
+                if test "$name" = '$1'; then
+                  LIB[]NAME[]_PREFIX="$basedir"
+                fi
+                additional_includedir="$basedir/include"
+                ;;
+              */$acl_libdirstem2 | */$acl_libdirstem2/)
+                basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e "s,/$acl_libdirstem2/"'*$,,'`
+                if test "$name" = '$1'; then
+                  LIB[]NAME[]_PREFIX="$basedir"
+                fi
+                additional_includedir="$basedir/include"
+                ;;
+            esac
+            if test "X$additional_includedir" != "X"; then
+              dnl Potentially add $additional_includedir to $INCNAME.
+              dnl But don't add it
+              dnl   1. if it's the standard /usr/include,
+              dnl   2. if it's /usr/local/include and we are using GCC on Linux,
+              dnl   3. if it's already present in $CPPFLAGS or the already
+              dnl      constructed $INCNAME,
+              dnl   4. if it doesn't exist as a directory.
+              if test "X$additional_includedir" != "X/usr/include"; then
+                haveit=
+                if test "X$additional_includedir" = "X/usr/local/include"; then
+                  if test -n "$GCC"; then
+                    case $host_os in
+                      linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+                    esac
+                  fi
+                fi
+                if test -z "$haveit"; then
+                  for x in $CPPFLAGS $INC[]NAME; do
+                    AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+                    if test "X$x" = "X-I$additional_includedir"; then
+                      haveit=yes
+                      break
+                    fi
+                  done
+                  if test -z "$haveit"; then
+                    if test -d "$additional_includedir"; then
+                      dnl Really add $additional_includedir to $INCNAME.
+                      INC[]NAME="${INC[]NAME}${INC[]NAME:+ }-I$additional_includedir"
+                    fi
+                  fi
+                fi
+              fi
+            fi
+            dnl Look for dependencies.
+            if test -n "$found_la"; then
+              dnl Read the .la file. It defines the variables
+              dnl dlname, library_names, old_library, dependency_libs, current,
+              dnl age, revision, installed, dlopen, dlpreopen, libdir.
+              save_libdir="$libdir"
+              case "$found_la" in
+                */* | *\\*) . "$found_la" ;;
+                *) . "./$found_la" ;;
+              esac
+              libdir="$save_libdir"
+              dnl We use only dependency_libs.
+              for dep in $dependency_libs; do
+                case "$dep" in
+                  -L*)
+                    additional_libdir=`echo "X$dep" | sed -e 's/^X-L//'`
+                    dnl Potentially add $additional_libdir to $LIBNAME and $LTLIBNAME.
+                    dnl But don't add it
+                    dnl   1. if it's the standard /usr/lib,
+                    dnl   2. if it's /usr/local/lib and we are using GCC on Linux,
+                    dnl   3. if it's already present in $LDFLAGS or the already
+                    dnl      constructed $LIBNAME,
+                    dnl   4. if it doesn't exist as a directory.
+                    if test "X$additional_libdir" != "X/usr/$acl_libdirstem" \
+                       && test "X$additional_libdir" != "X/usr/$acl_libdirstem2"; then
+                      haveit=
+                      if test "X$additional_libdir" = "X/usr/local/$acl_libdirstem" \
+                         || test "X$additional_libdir" = "X/usr/local/$acl_libdirstem2"; then
+                        if test -n "$GCC"; then
+                          case $host_os in
+                            linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+                          esac
+                        fi
+                      fi
+                      if test -z "$haveit"; then
+                        haveit=
+                        for x in $LDFLAGS $LIB[]NAME; do
+                          AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+                          if test "X$x" = "X-L$additional_libdir"; then
+                            haveit=yes
+                            break
+                          fi
+                        done
+                        if test -z "$haveit"; then
+                          if test -d "$additional_libdir"; then
+                            dnl Really add $additional_libdir to $LIBNAME.
+                            LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$additional_libdir"
+                          fi
+                        fi
+                        haveit=
+                        for x in $LDFLAGS $LTLIB[]NAME; do
+                          AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+                          if test "X$x" = "X-L$additional_libdir"; then
+                            haveit=yes
+                            break
+                          fi
+                        done
+                        if test -z "$haveit"; then
+                          if test -d "$additional_libdir"; then
+                            dnl Really add $additional_libdir to $LTLIBNAME.
+                            LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$additional_libdir"
+                          fi
+                        fi
+                      fi
+                    fi
+                    ;;
+                  -R*)
+                    dir=`echo "X$dep" | sed -e 's/^X-R//'`
+                    if test "$enable_rpath" != no; then
+                      dnl Potentially add DIR to rpathdirs.
+                      dnl The rpathdirs will be appended to $LIBNAME at the end.
+                      haveit=
+                      for x in $rpathdirs; do
+                        if test "X$x" = "X$dir"; then
+                          haveit=yes
+                          break
+                        fi
+                      done
+                      if test -z "$haveit"; then
+                        rpathdirs="$rpathdirs $dir"
+                      fi
+                      dnl Potentially add DIR to ltrpathdirs.
+                      dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
+                      haveit=
+                      for x in $ltrpathdirs; do
+                        if test "X$x" = "X$dir"; then
+                          haveit=yes
+                          break
+                        fi
+                      done
+                      if test -z "$haveit"; then
+                        ltrpathdirs="$ltrpathdirs $dir"
+                      fi
+                    fi
+                    ;;
+                  -l*)
+                    dnl Handle this in the next round.
+                    names_next_round="$names_next_round "`echo "X$dep" | sed -e 's/^X-l//'`
+                    ;;
+                  *.la)
+                    dnl Handle this in the next round. Throw away the .la's
+                    dnl directory; it is already contained in a preceding -L
+                    dnl option.
+                    names_next_round="$names_next_round "`echo "X$dep" | sed -e 's,^X.*/,,' -e 's,^lib,,' -e 's,\.la$,,'`
+                    ;;
+                  *)
+                    dnl Most likely an immediate library name.
+                    LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$dep"
+                    LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$dep"
+                    ;;
+                esac
+              done
+            fi
+          else
+            dnl Didn't find the library; assume it is in the system directories
+            dnl known to the linker and runtime loader. (All the system
+            dnl directories known to the linker should also be known to the
+            dnl runtime loader, otherwise the system is severely misconfigured.)
+            LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
+            LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-l$name"
+          fi
+        fi
+      fi
+    done
+  done
+  if test "X$rpathdirs" != "X"; then
+    if test -n "$acl_hardcode_libdir_separator"; then
+      dnl Weird platform: only the last -rpath option counts, the user must
+      dnl pass all path elements in one option. We can arrange that for a
+      dnl single library, but not when more than one $LIBNAMEs are used.
+      alldirs=
+      for found_dir in $rpathdirs; do
+        alldirs="${alldirs}${alldirs:+$acl_hardcode_libdir_separator}$found_dir"
+      done
+      dnl Note: acl_hardcode_libdir_flag_spec uses $libdir and $wl.
+      acl_save_libdir="$libdir"
+      libdir="$alldirs"
+      eval flag=\"$acl_hardcode_libdir_flag_spec\"
+      libdir="$acl_save_libdir"
+      LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
+    else
+      dnl The -rpath options are cumulative.
+      for found_dir in $rpathdirs; do
+        acl_save_libdir="$libdir"
+        libdir="$found_dir"
+        eval flag=\"$acl_hardcode_libdir_flag_spec\"
+        libdir="$acl_save_libdir"
+        LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
+      done
+    fi
+  fi
+  if test "X$ltrpathdirs" != "X"; then
+    dnl When using libtool, the option that works for both libraries and
+    dnl executables is -R. The -R options are cumulative.
+    for found_dir in $ltrpathdirs; do
+      LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-R$found_dir"
+    done
+  fi
+  popdef([P_A_C_K])
+  popdef([PACKLIBS])
+  popdef([PACKUP])
+  popdef([PACK])
+  popdef([NAME])
+])
+
+dnl AC_LIB_APPENDTOVAR(VAR, CONTENTS) appends the elements of CONTENTS to VAR,
+dnl unless already present in VAR.
+dnl Works only for CPPFLAGS, not for LIB* variables because that sometimes
+dnl contains two or three consecutive elements that belong together.
+AC_DEFUN([AC_LIB_APPENDTOVAR],
+[
+  for element in [$2]; do
+    haveit=
+    for x in $[$1]; do
+      AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+      if test "X$x" = "X$element"; then
+        haveit=yes
+        break
+      fi
+    done
+    if test -z "$haveit"; then
+      [$1]="${[$1]}${[$1]:+ }$element"
+    fi
+  done
+])
+
+dnl For those cases where a variable contains several -L and -l options
+dnl referring to unknown libraries and directories, this macro determines the
+dnl necessary additional linker options for the runtime path.
+dnl AC_LIB_LINKFLAGS_FROM_LIBS([LDADDVAR], [LIBSVALUE], [USE-LIBTOOL])
+dnl sets LDADDVAR to linker options needed together with LIBSVALUE.
+dnl If USE-LIBTOOL evaluates to non-empty, linking with libtool is assumed,
+dnl otherwise linking without libtool is assumed.
+AC_DEFUN([AC_LIB_LINKFLAGS_FROM_LIBS],
+[
+  AC_REQUIRE([AC_LIB_RPATH])
+  AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])
+  $1=
+  if test "$enable_rpath" != no; then
+    if test -n "$acl_hardcode_libdir_flag_spec" && test "$acl_hardcode_minus_L" = no; then
+      dnl Use an explicit option to hardcode directories into the resulting
+      dnl binary.
+      rpathdirs=
+      next=
+      for opt in $2; do
+        if test -n "$next"; then
+          dir="$next"
+          dnl No need to hardcode the standard /usr/lib.
+          if test "X$dir" != "X/usr/$acl_libdirstem" \
+             && test "X$dir" != "X/usr/$acl_libdirstem2"; then
+            rpathdirs="$rpathdirs $dir"
+          fi
+          next=
+        else
+          case $opt in
+            -L) next=yes ;;
+            -L*) dir=`echo "X$opt" | sed -e 's,^X-L,,'`
+                 dnl No need to hardcode the standard /usr/lib.
+                 if test "X$dir" != "X/usr/$acl_libdirstem" \
+                    && test "X$dir" != "X/usr/$acl_libdirstem2"; then
+                   rpathdirs="$rpathdirs $dir"
+                 fi
+                 next= ;;
+            *) next= ;;
+          esac
+        fi
+      done
+      if test "X$rpathdirs" != "X"; then
+        if test -n ""$3""; then
+          dnl libtool is used for linking. Use -R options.
+          for dir in $rpathdirs; do
+            $1="${$1}${$1:+ }-R$dir"
+          done
+        else
+          dnl The linker is used for linking directly.
+          if test -n "$acl_hardcode_libdir_separator"; then
+            dnl Weird platform: only the last -rpath option counts, the user
+            dnl must pass all path elements in one option.
+            alldirs=
+            for dir in $rpathdirs; do
+              alldirs="${alldirs}${alldirs:+$acl_hardcode_libdir_separator}$dir"
+            done
+            acl_save_libdir="$libdir"
+            libdir="$alldirs"
+            eval flag=\"$acl_hardcode_libdir_flag_spec\"
+            libdir="$acl_save_libdir"
+            $1="$flag"
+          else
+            dnl The -rpath options are cumulative.
+            for dir in $rpathdirs; do
+              acl_save_libdir="$libdir"
+              libdir="$dir"
+              eval flag=\"$acl_hardcode_libdir_flag_spec\"
+              libdir="$acl_save_libdir"
+              $1="${$1}${$1:+ }$flag"
+            done
+          fi
+        fi
+      fi
+    fi
+  fi
+  AC_SUBST([$1])
+])
diff --git a/gnulib/import/m4/lib-prefix.m4 b/gnulib/import/m4/lib-prefix.m4
new file mode 100644
index 0000000..6851031
--- /dev/null
+++ b/gnulib/import/m4/lib-prefix.m4
@@ -0,0 +1,224 @@ 
+# lib-prefix.m4 serial 7 (gettext-0.18)
+dnl Copyright (C) 2001-2005, 2008-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl AC_LIB_ARG_WITH is synonymous to AC_ARG_WITH in autoconf-2.13, and
+dnl similar to AC_ARG_WITH in autoconf 2.52...2.57 except that is doesn't
+dnl require excessive bracketing.
+ifdef([AC_HELP_STRING],
+[AC_DEFUN([AC_LIB_ARG_WITH], [AC_ARG_WITH([$1],[[$2]],[$3],[$4])])],
+[AC_DEFUN([AC_][LIB_ARG_WITH], [AC_ARG_WITH([$1],[$2],[$3],[$4])])])
+
+dnl AC_LIB_PREFIX adds to the CPPFLAGS and LDFLAGS the flags that are needed
+dnl to access previously installed libraries. The basic assumption is that
+dnl a user will want packages to use other packages he previously installed
+dnl with the same --prefix option.
+dnl This macro is not needed if only AC_LIB_LINKFLAGS is used to locate
+dnl libraries, but is otherwise very convenient.
+AC_DEFUN([AC_LIB_PREFIX],
+[
+  AC_BEFORE([$0], [AC_LIB_LINKFLAGS])
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])
+  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
+  dnl By default, look in $includedir and $libdir.
+  use_additional=yes
+  AC_LIB_WITH_FINAL_PREFIX([
+    eval additional_includedir=\"$includedir\"
+    eval additional_libdir=\"$libdir\"
+  ])
+  AC_LIB_ARG_WITH([lib-prefix],
+[  --with-lib-prefix[=DIR] search for libraries in DIR/include and DIR/lib
+  --without-lib-prefix    don't search for libraries in includedir and libdir],
+[
+    if test "X$withval" = "Xno"; then
+      use_additional=no
+    else
+      if test "X$withval" = "X"; then
+        AC_LIB_WITH_FINAL_PREFIX([
+          eval additional_includedir=\"$includedir\"
+          eval additional_libdir=\"$libdir\"
+        ])
+      else
+        additional_includedir="$withval/include"
+        additional_libdir="$withval/$acl_libdirstem"
+      fi
+    fi
+])
+  if test $use_additional = yes; then
+    dnl Potentially add $additional_includedir to $CPPFLAGS.
+    dnl But don't add it
+    dnl   1. if it's the standard /usr/include,
+    dnl   2. if it's already present in $CPPFLAGS,
+    dnl   3. if it's /usr/local/include and we are using GCC on Linux,
+    dnl   4. if it doesn't exist as a directory.
+    if test "X$additional_includedir" != "X/usr/include"; then
+      haveit=
+      for x in $CPPFLAGS; do
+        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+        if test "X$x" = "X-I$additional_includedir"; then
+          haveit=yes
+          break
+        fi
+      done
+      if test -z "$haveit"; then
+        if test "X$additional_includedir" = "X/usr/local/include"; then
+          if test -n "$GCC"; then
+            case $host_os in
+              linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+            esac
+          fi
+        fi
+        if test -z "$haveit"; then
+          if test -d "$additional_includedir"; then
+            dnl Really add $additional_includedir to $CPPFLAGS.
+            CPPFLAGS="${CPPFLAGS}${CPPFLAGS:+ }-I$additional_includedir"
+          fi
+        fi
+      fi
+    fi
+    dnl Potentially add $additional_libdir to $LDFLAGS.
+    dnl But don't add it
+    dnl   1. if it's the standard /usr/lib,
+    dnl   2. if it's already present in $LDFLAGS,
+    dnl   3. if it's /usr/local/lib and we are using GCC on Linux,
+    dnl   4. if it doesn't exist as a directory.
+    if test "X$additional_libdir" != "X/usr/$acl_libdirstem"; then
+      haveit=
+      for x in $LDFLAGS; do
+        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+        if test "X$x" = "X-L$additional_libdir"; then
+          haveit=yes
+          break
+        fi
+      done
+      if test -z "$haveit"; then
+        if test "X$additional_libdir" = "X/usr/local/$acl_libdirstem"; then
+          if test -n "$GCC"; then
+            case $host_os in
+              linux*) haveit=yes;;
+            esac
+          fi
+        fi
+        if test -z "$haveit"; then
+          if test -d "$additional_libdir"; then
+            dnl Really add $additional_libdir to $LDFLAGS.
+            LDFLAGS="${LDFLAGS}${LDFLAGS:+ }-L$additional_libdir"
+          fi
+        fi
+      fi
+    fi
+  fi
+])
+
+dnl AC_LIB_PREPARE_PREFIX creates variables acl_final_prefix,
+dnl acl_final_exec_prefix, containing the values to which $prefix and
+dnl $exec_prefix will expand at the end of the configure script.
+AC_DEFUN([AC_LIB_PREPARE_PREFIX],
+[
+  dnl Unfortunately, prefix and exec_prefix get only finally determined
+  dnl at the end of configure.
+  if test "X$prefix" = "XNONE"; then
+    acl_final_prefix="$ac_default_prefix"
+  else
+    acl_final_prefix="$prefix"
+  fi
+  if test "X$exec_prefix" = "XNONE"; then
+    acl_final_exec_prefix='${prefix}'
+  else
+    acl_final_exec_prefix="$exec_prefix"
+  fi
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  eval acl_final_exec_prefix=\"$acl_final_exec_prefix\"
+  prefix="$acl_save_prefix"
+])
+
+dnl AC_LIB_WITH_FINAL_PREFIX([statement]) evaluates statement, with the
+dnl variables prefix and exec_prefix bound to the values they will have
+dnl at the end of the configure script.
+AC_DEFUN([AC_LIB_WITH_FINAL_PREFIX],
+[
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  $1
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+])
+
+dnl AC_LIB_PREPARE_MULTILIB creates
+dnl - a variable acl_libdirstem, containing the basename of the libdir, either
+dnl   "lib" or "lib64" or "lib/64",
+dnl - a variable acl_libdirstem2, as a secondary possible value for
+dnl   acl_libdirstem, either the same as acl_libdirstem or "lib/sparcv9" or
+dnl   "lib/amd64".
+AC_DEFUN([AC_LIB_PREPARE_MULTILIB],
+[
+  dnl There is no formal standard regarding lib and lib64.
+  dnl On glibc systems, the current practice is that on a system supporting
+  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under
+  dnl $prefix/lib64 and 32-bit libraries go under $prefix/lib. We determine
+  dnl the compiler's default mode by looking at the compiler's library search
+  dnl path. If at least one of its elements ends in /lib64 or points to a
+  dnl directory whose absolute pathname ends in /lib64, we assume a 64-bit ABI.
+  dnl Otherwise we use the default, namely "lib".
+  dnl On Solaris systems, the current practice is that on a system supporting
+  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under
+  dnl $prefix/lib/64 (which is a symlink to either $prefix/lib/sparcv9 or
+  dnl $prefix/lib/amd64) and 32-bit libraries go under $prefix/lib.
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  acl_libdirstem=lib
+  acl_libdirstem2=
+  case "$host_os" in
+    solaris*)
+      dnl See Solaris 10 Software Developer Collection > Solaris 64-bit Developer's Guide > The Development Environment
+      dnl <http://docs.sun.com/app/docs/doc/816-5138/dev-env?l=en&a=view>.
+      dnl "Portable Makefiles should refer to any library directories using the 64 symbolic link."
+      dnl But we want to recognize the sparcv9 or amd64 subdirectory also if the
+      dnl symlink is missing, so we set acl_libdirstem2 too.
+      AC_CACHE_CHECK([for 64-bit host], [gl_cv_solaris_64bit],
+        [AC_EGREP_CPP([sixtyfour bits], [
+#ifdef _LP64
+sixtyfour bits
+#endif
+           ], [gl_cv_solaris_64bit=yes], [gl_cv_solaris_64bit=no])
+        ])
+      if test $gl_cv_solaris_64bit = yes; then
+        acl_libdirstem=lib/64
+        case "$host_cpu" in
+          sparc*)        acl_libdirstem2=lib/sparcv9 ;;
+          i*86 | x86_64) acl_libdirstem2=lib/amd64 ;;
+        esac
+      fi
+      ;;
+    *)
+      searchpath=`(LC_ALL=C $CC -print-search-dirs) 2>/dev/null | sed -n -e 's,^libraries: ,,p' | sed -e 's,^=,,'`
+      if test -n "$searchpath"; then
+        acl_save_IFS="${IFS= 	}"; IFS=":"
+        for searchdir in $searchpath; do
+          if test -d "$searchdir"; then
+            case "$searchdir" in
+              */lib64/ | */lib64 ) acl_libdirstem=lib64 ;;
+              */../ | */.. )
+                # Better ignore directories of this form. They are misleading.
+                ;;
+              *) searchdir=`cd "$searchdir" && pwd`
+                 case "$searchdir" in
+                   */lib64 ) acl_libdirstem=lib64 ;;
+                 esac ;;
+            esac
+          fi
+        done
+        IFS="$acl_save_IFS"
+      fi
+      ;;
+  esac
+  test -n "$acl_libdirstem2" || acl_libdirstem2="$acl_libdirstem"
+])
diff --git a/gnulib/import/m4/lock.m4 b/gnulib/import/m4/lock.m4
new file mode 100644
index 0000000..1e83e23
--- /dev/null
+++ b/gnulib/import/m4/lock.m4
@@ -0,0 +1,42 @@ 
+# lock.m4 serial 13 (gettext-0.18.2)
+dnl Copyright (C) 2005-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+AC_DEFUN([gl_LOCK],
+[
+  AC_REQUIRE([gl_THREADLIB])
+  if test "$gl_threads_api" = posix; then
+    # OSF/1 4.0 and Mac OS X 10.1 lack the pthread_rwlock_t type and the
+    # pthread_rwlock_* functions.
+    AC_CHECK_TYPE([pthread_rwlock_t],
+      [AC_DEFINE([HAVE_PTHREAD_RWLOCK], [1],
+         [Define if the POSIX multithreading library has read/write locks.])],
+      [],
+      [#include <pthread.h>])
+    # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro.
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM(
+        [[#include <pthread.h>]],
+        [[
+#if __FreeBSD__ == 4
+error "No, in FreeBSD 4.0 recursive mutexes actually don't work."
+#elif (defined __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ \
+       && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070)
+error "No, in Mac OS X < 10.7 recursive mutexes actually don't work."
+#else
+int x = (int)PTHREAD_MUTEX_RECURSIVE;
+return !x;
+#endif
+        ]])],
+      [AC_DEFINE([HAVE_PTHREAD_MUTEX_RECURSIVE], [1],
+         [Define if the <pthread.h> defines PTHREAD_MUTEX_RECURSIVE.])])
+  fi
+  gl_PREREQ_LOCK
+])
+
+# Prerequisites of lib/glthread/lock.c.
+AC_DEFUN([gl_PREREQ_LOCK], [:])
diff --git a/gnulib/import/m4/strerror_r.m4 b/gnulib/import/m4/strerror_r.m4
new file mode 100644
index 0000000..aa0ea44
--- /dev/null
+++ b/gnulib/import/m4/strerror_r.m4
@@ -0,0 +1,187 @@ 
+# strerror_r.m4 serial 18
+dnl Copyright (C) 2002, 2007-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_STRERROR_R],
+[
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
+
+  dnl Persuade Solaris <string.h> to declare strerror_r().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  dnl Some systems don't declare strerror_r() if _THREAD_SAFE and _REENTRANT
+  dnl are not defined.
+  AC_CHECK_DECL([strerror_r],
+    [HAVE_DECL_STRERROR_R=1], [HAVE_DECL_STRERROR_R=0])
+  AC_DEFINE_UNQUOTED([HAVE_DECL_STRERROR_R_ORIG], [$HAVE_DECL_STRERROR_R],
+    [Define to 1 if you have the declaration of 'strerror_r' in the system include files, or to 0 otherwise.])
+
+  if test $ac_cv_func_strerror_r = yes; then
+    if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
+      if test $gl_cv_func_strerror_r_posix_signature = yes; then
+        case "$gl_cv_func_strerror_r_works" in
+          dnl The system's strerror_r has bugs.  Replace it.
+          *no) REPLACE_STRERROR_R=1 ;;
+        esac
+      else
+        dnl The system's strerror_r() has a wrong signature. Replace it.
+        REPLACE_STRERROR_R=1
+      fi
+    else
+      dnl The system's strerror_r() cannot know about the new errno values we
+      dnl add to <errno.h>, or any fix for strerror(0). Replace it.
+      REPLACE_STRERROR_R=1
+    fi
+  fi
+
+  # Overwrite the findings of AC_FUNC_STRERROR_R (for code that uses that).
+  AC_REQUIRE([AC_FUNC_STRERROR_R])
+])
+
+# If this module is in use, we unconditionally want POSIX semantics; so
+# replace autoconf's macro with a version that does not probe
+AC_DEFUN([AC_FUNC_STRERROR_R], [
+  AC_DEFINE([HAVE_DECL_STRERROR_R], [1],
+    [Define to 1, since you should have the declaration of strerror_r.])
+  AC_DEFINE([HAVE_STRERROR_R], [1],
+    [Define to 1, since you should have the function strerror_r.])
+  AC_DEFINE([STRERROR_R_CHAR_P], [0],
+    [Define to 0, since strerror_r should not return char *.])
+])
+
+# Prerequisites of lib/strerror_r.c.
+AC_DEFUN([gl_PREREQ_STRERROR_R], [
+  dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
+  AC_CHECK_FUNCS_ONCE([__xpg_strerror_r])
+  AC_CHECK_FUNCS_ONCE([catgets])
+  AC_CHECK_FUNCS_ONCE([snprintf])
+])
+
+# Detect if strerror_r works, but without affecting whether a replacement
+# strerror_r will be used.
+AC_DEFUN([gl_FUNC_STRERROR_R_WORKS],
+[
+  AC_REQUIRE([gl_HEADER_ERRNO_H])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([gl_FUNC_STRERROR_0])
+
+  AC_CHECK_FUNC([strerror_r])
+  if test $ac_cv_func_strerror_r = yes; then
+    if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
+      dnl The POSIX prototype is:  int strerror_r (int, char *, size_t);
+      dnl glibc, Cygwin:           char *strerror_r (int, char *, size_t);
+      dnl AIX 5.1, OSF/1 5.1:      int strerror_r (int, char *, int);
+      AC_CACHE_CHECK([for strerror_r with POSIX signature],
+        [gl_cv_func_strerror_r_posix_signature],
+        [AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM(
+              [[#include <string.h>
+                int strerror_r (int, char *, size_t);
+              ]],
+              [])],
+           [gl_cv_func_strerror_r_posix_signature=yes],
+           [gl_cv_func_strerror_r_posix_signature=no])
+        ])
+      if test $gl_cv_func_strerror_r_posix_signature = yes; then
+        dnl AIX 6.1 strerror_r fails by returning -1, not an error number.
+        dnl HP-UX 11.31 strerror_r always fails when the buffer length argument
+        dnl is less than 80.
+        dnl FreeBSD 8.s strerror_r claims failure on 0
+        dnl Mac OS X 10.5 strerror_r treats 0 like -1
+        dnl Solaris 10 strerror_r corrupts errno on failure
+        AC_CACHE_CHECK([whether strerror_r works],
+          [gl_cv_func_strerror_r_works],
+          [AC_RUN_IFELSE(
+             [AC_LANG_PROGRAM(
+                [[#include <errno.h>
+                  #include <string.h>
+                ]],
+                [[int result = 0;
+                  char buf[79];
+                  if (strerror_r (EACCES, buf, 0) < 0)
+                    result |= 1;
+                  errno = 0;
+                  if (strerror_r (EACCES, buf, sizeof buf) != 0)
+                    result |= 2;
+                  strcpy (buf, "Unknown");
+                  if (strerror_r (0, buf, sizeof buf) != 0)
+                    result |= 4;
+                  if (errno)
+                    result |= 8;
+                  if (strstr (buf, "nknown") || strstr (buf, "ndefined"))
+                    result |= 0x10;
+                  errno = 0;
+                  *buf = 0;
+                  if (strerror_r (-3, buf, sizeof buf) < 0)
+                    result |= 0x20;
+                  if (errno)
+                    result |= 0x40;
+                  if (!*buf)
+                    result |= 0x80;
+                  return result;
+                ]])],
+             [gl_cv_func_strerror_r_works=yes],
+             [gl_cv_func_strerror_r_works=no],
+             [
+changequote(,)dnl
+              case "$host_os" in
+                       # Guess no on AIX.
+                aix*)  gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess no on HP-UX.
+                hpux*) gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess no on BSD variants.
+                *bsd*)  gl_cv_func_strerror_r_works="guessing no";;
+                       # Guess yes otherwise.
+                *)     gl_cv_func_strerror_r_works="guessing yes";;
+              esac
+changequote([,])dnl
+             ])
+          ])
+      else
+        dnl The system's strerror() has a wrong signature.
+        dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
+        AC_CHECK_FUNCS_ONCE([__xpg_strerror_r])
+        dnl In glibc < 2.14, __xpg_strerror_r does not populate buf on failure.
+        dnl In cygwin < 1.7.10, __xpg_strerror_r clobbers strerror's buffer.
+        if test $ac_cv_func___xpg_strerror_r = yes; then
+          AC_CACHE_CHECK([whether __xpg_strerror_r works],
+            [gl_cv_func_strerror_r_works],
+            [AC_RUN_IFELSE(
+               [AC_LANG_PROGRAM(
+                  [[#include <errno.h>
+                    #include <string.h>
+                    extern
+                    #ifdef __cplusplus
+                    "C"
+                    #endif
+                    int __xpg_strerror_r(int, char *, size_t);
+                  ]],
+                  [[int result = 0;
+                    char buf[256] = "^";
+                    char copy[256];
+                    char *str = strerror (-1);
+                    strcpy (copy, str);
+                    if (__xpg_strerror_r (-2, buf, 1) == 0)
+                      result |= 1;
+                    if (*buf)
+                      result |= 2;
+                    __xpg_strerror_r (-2, buf, 256);
+                    if (strcmp (str, copy))
+                      result |= 4;
+                    return result;
+                  ]])],
+               [gl_cv_func_strerror_r_works=yes],
+               [gl_cv_func_strerror_r_works=no],
+               [dnl Guess no on all platforms that have __xpg_strerror_r,
+                dnl at least until fixed glibc and cygwin are more common.
+                gl_cv_func_strerror_r_works="guessing no"
+               ])
+            ])
+        fi
+      fi
+    fi
+  fi
+])
diff --git a/gnulib/import/m4/threadlib.m4 b/gnulib/import/m4/threadlib.m4
new file mode 100644
index 0000000..b43534e
--- /dev/null
+++ b/gnulib/import/m4/threadlib.m4
@@ -0,0 +1,389 @@ 
+# threadlib.m4 serial 11 (gettext-0.18.2)
+dnl Copyright (C) 2005-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl gl_THREADLIB
+dnl ------------
+dnl Tests for a multithreading library to be used.
+dnl If the configure.ac contains a definition of the gl_THREADLIB_DEFAULT_NO
+dnl (it must be placed before the invocation of gl_THREADLIB_EARLY!), then the
+dnl default is 'no', otherwise it is system dependent. In both cases, the user
+dnl can change the choice through the options --enable-threads=choice or
+dnl --disable-threads.
+dnl Defines at most one of the macros USE_POSIX_THREADS, USE_SOLARIS_THREADS,
+dnl USE_PTH_THREADS, USE_WINDOWS_THREADS
+dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use
+dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with
+dnl libtool).
+dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for
+dnl programs that really need multithread functionality. The difference
+dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak
+dnl symbols, typically LIBTHREAD is empty whereas LIBMULTITHREAD is not.
+dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for
+dnl multithread-safe programs.
+
+AC_DEFUN([gl_THREADLIB_EARLY],
+[
+  AC_REQUIRE([gl_THREADLIB_EARLY_BODY])
+])
+
+dnl The guts of gl_THREADLIB_EARLY. Needs to be expanded only once.
+
+AC_DEFUN([gl_THREADLIB_EARLY_BODY],
+[
+  dnl Ordering constraints: This macro modifies CPPFLAGS in a way that
+  dnl influences the result of the autoconf tests that test for *_unlocked
+  dnl declarations, on AIX 5 at least. Therefore it must come early.
+  AC_BEFORE([$0], [gl_FUNC_GLIBC_UNLOCKED_IO])dnl
+  AC_BEFORE([$0], [gl_ARGP])dnl
+
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems.
+  dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes
+  dnl AC_GNU_SOURCE.
+  m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
+    [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
+    [AC_REQUIRE([AC_GNU_SOURCE])])
+  dnl Check for multithreading.
+  m4_ifdef([gl_THREADLIB_DEFAULT_NO],
+    [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])],
+    [m4_divert_text([DEFAULTS], [gl_use_threads_default=])])
+  AC_ARG_ENABLE([threads],
+AC_HELP_STRING([--enable-threads={posix|solaris|pth|windows}], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [
+AC_HELP_STRING([--disable-threads], [build without multithread safety])]),
+    [gl_use_threads=$enableval],
+    [if test -n "$gl_use_threads_default"; then
+       gl_use_threads="$gl_use_threads_default"
+     else
+changequote(,)dnl
+       case "$host_os" in
+         dnl Disable multithreading by default on OSF/1, because it interferes
+         dnl with fork()/exec(): When msgexec is linked with -lpthread, its
+         dnl child process gets an endless segmentation fault inside execvp().
+         dnl Disable multithreading by default on Cygwin 1.5.x, because it has
+         dnl bugs that lead to endless loops or crashes. See
+         dnl <http://cygwin.com/ml/cygwin/2009-08/msg00283.html>.
+         osf*) gl_use_threads=no ;;
+         cygwin*)
+               case `uname -r` in
+                 1.[0-5].*) gl_use_threads=no ;;
+                 *)         gl_use_threads=yes ;;
+               esac
+               ;;
+         *)    gl_use_threads=yes ;;
+       esac
+changequote([,])dnl
+     fi
+    ])
+  if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+    # For using <pthread.h>:
+    case "$host_os" in
+      osf*)
+        # On OSF/1, the compiler needs the flag -D_REENTRANT so that it
+        # groks <pthread.h>. cc also understands the flag -pthread, but
+        # we don't use it because 1. gcc-2.95 doesn't understand -pthread,
+        # 2. putting a flag into CPPFLAGS that has an effect on the linker
+        # causes the AC_LINK_IFELSE test below to succeed unexpectedly,
+        # leading to wrong values of LIBTHREAD and LTLIBTHREAD.
+        CPPFLAGS="$CPPFLAGS -D_REENTRANT"
+        ;;
+    esac
+    # Some systems optimize for single-threaded programs by default, and
+    # need special flags to disable these optimizations. For example, the
+    # definition of 'errno' in <errno.h>.
+    case "$host_os" in
+      aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;;
+      solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;;
+    esac
+  fi
+])
+
+dnl The guts of gl_THREADLIB. Needs to be expanded only once.
+
+AC_DEFUN([gl_THREADLIB_BODY],
+[
+  AC_REQUIRE([gl_THREADLIB_EARLY_BODY])
+  gl_threads_api=none
+  LIBTHREAD=
+  LTLIBTHREAD=
+  LIBMULTITHREAD=
+  LTLIBMULTITHREAD=
+  if test "$gl_use_threads" != no; then
+    dnl Check whether the compiler and linker support weak declarations.
+    AC_CACHE_CHECK([whether imported symbols can be declared weak],
+      [gl_cv_have_weak],
+      [gl_cv_have_weak=no
+       dnl First, test whether the compiler accepts it syntactically.
+       AC_LINK_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[extern void xyzzy ();
+#pragma weak xyzzy]],
+            [[xyzzy();]])],
+         [gl_cv_have_weak=maybe])
+       if test $gl_cv_have_weak = maybe; then
+         dnl Second, test whether it actually works. On Cygwin 1.7.2, with
+         dnl gcc 4.3, symbols declared weak always evaluate to the address 0.
+         AC_RUN_IFELSE(
+           [AC_LANG_SOURCE([[
+#include <stdio.h>
+#pragma weak fputs
+int main ()
+{
+  return (fputs == NULL);
+}]])],
+           [gl_cv_have_weak=yes],
+           [gl_cv_have_weak=no],
+           [dnl When cross-compiling, assume that only ELF platforms support
+            dnl weak symbols.
+            AC_EGREP_CPP([Extensible Linking Format],
+              [#ifdef __ELF__
+               Extensible Linking Format
+               #endif
+              ],
+              [gl_cv_have_weak="guessing yes"],
+              [gl_cv_have_weak="guessing no"])
+           ])
+       fi
+      ])
+    if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+      # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
+      # it groks <pthread.h>. It's added above, in gl_THREADLIB_EARLY_BODY.
+      AC_CHECK_HEADER([pthread.h],
+        [gl_have_pthread_h=yes], [gl_have_pthread_h=no])
+      if test "$gl_have_pthread_h" = yes; then
+        # Other possible tests:
+        #   -lpthreads (FSU threads, PCthreads)
+        #   -lgthreads
+        gl_have_pthread=
+        # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
+        # in libc. IRIX 6.5 has the first one in both libc and libpthread, but
+        # the second one only in libpthread, and lock.c needs it.
+        #
+        # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
+        # needs -pthread for some reason.  See:
+        # http://lists.gnu.org/archive/html/bug-gnulib/2014-09/msg00023.html
+        save_LIBS=$LIBS
+        for gl_pthread in '' '-pthread'; do
+          LIBS="$LIBS $gl_pthread"
+          AC_LINK_IFELSE(
+            [AC_LANG_PROGRAM(
+               [[#include <pthread.h>
+                 pthread_mutex_t m;
+                 pthread_mutexattr_t ma;
+               ]],
+               [[pthread_mutex_lock (&m);
+                 pthread_mutexattr_init (&ma);]])],
+            [gl_have_pthread=yes
+             LIBTHREAD=$gl_pthread LTLIBTHREAD=$gl_pthread
+             LIBMULTITHREAD=$gl_pthread LTLIBMULTITHREAD=$gl_pthread])
+          LIBS=$save_LIBS
+          test -n "$gl_have_pthread" && break
+        done
+
+        # Test for libpthread by looking for pthread_kill. (Not pthread_self,
+        # since it is defined as a macro on OSF/1.)
+        if test -n "$gl_have_pthread" && test -z "$LIBTHREAD"; then
+          # The program links fine without libpthread. But it may actually
+          # need to link with libpthread in order to create multiple threads.
+          AC_CHECK_LIB([pthread], [pthread_kill],
+            [LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread
+             # On Solaris and HP-UX, most pthread functions exist also in libc.
+             # Therefore pthread_in_use() needs to actually try to create a
+             # thread: pthread_create from libc will fail, whereas
+             # pthread_create will actually create a thread.
+             case "$host_os" in
+               solaris* | hpux*)
+                 AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1],
+                   [Define if the pthread_in_use() detection is hard.])
+             esac
+            ])
+        elif test -z "$gl_have_pthread"; then
+          # Some library is needed. Try libpthread and libc_r.
+          AC_CHECK_LIB([pthread], [pthread_kill],
+            [gl_have_pthread=yes
+             LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread
+             LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread])
+          if test -z "$gl_have_pthread"; then
+            # For FreeBSD 4.
+            AC_CHECK_LIB([c_r], [pthread_kill],
+              [gl_have_pthread=yes
+               LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r
+               LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r])
+          fi
+        fi
+        if test -n "$gl_have_pthread"; then
+          gl_threads_api=posix
+          AC_DEFINE([USE_POSIX_THREADS], [1],
+            [Define if the POSIX multithreading library can be used.])
+          if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+            if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+              AC_DEFINE([USE_POSIX_THREADS_WEAK], [1],
+                [Define if references to the POSIX multithreading library should be made weak.])
+              LIBTHREAD=
+              LTLIBTHREAD=
+            fi
+          fi
+        fi
+      fi
+    fi
+    if test -z "$gl_have_pthread"; then
+      if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then
+        gl_have_solaristhread=
+        gl_save_LIBS="$LIBS"
+        LIBS="$LIBS -lthread"
+        AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM(
+             [[
+#include <thread.h>
+#include <synch.h>
+             ]],
+             [[thr_self();]])],
+          [gl_have_solaristhread=yes])
+        LIBS="$gl_save_LIBS"
+        if test -n "$gl_have_solaristhread"; then
+          gl_threads_api=solaris
+          LIBTHREAD=-lthread
+          LTLIBTHREAD=-lthread
+          LIBMULTITHREAD="$LIBTHREAD"
+          LTLIBMULTITHREAD="$LTLIBTHREAD"
+          AC_DEFINE([USE_SOLARIS_THREADS], [1],
+            [Define if the old Solaris multithreading library can be used.])
+          if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+            AC_DEFINE([USE_SOLARIS_THREADS_WEAK], [1],
+              [Define if references to the old Solaris multithreading library should be made weak.])
+            LIBTHREAD=
+            LTLIBTHREAD=
+          fi
+        fi
+      fi
+    fi
+    if test "$gl_use_threads" = pth; then
+      gl_save_CPPFLAGS="$CPPFLAGS"
+      AC_LIB_LINKFLAGS([pth])
+      gl_have_pth=
+      gl_save_LIBS="$LIBS"
+      LIBS="$LIBS $LIBPTH"
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM([[#include <pth.h>]], [[pth_self();]])],
+        [gl_have_pth=yes])
+      LIBS="$gl_save_LIBS"
+      if test -n "$gl_have_pth"; then
+        gl_threads_api=pth
+        LIBTHREAD="$LIBPTH"
+        LTLIBTHREAD="$LTLIBPTH"
+        LIBMULTITHREAD="$LIBTHREAD"
+        LTLIBMULTITHREAD="$LTLIBTHREAD"
+        AC_DEFINE([USE_PTH_THREADS], [1],
+          [Define if the GNU Pth multithreading library can be used.])
+        if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+          if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+            AC_DEFINE([USE_PTH_THREADS_WEAK], [1],
+              [Define if references to the GNU Pth multithreading library should be made weak.])
+            LIBTHREAD=
+            LTLIBTHREAD=
+          fi
+        fi
+      else
+        CPPFLAGS="$gl_save_CPPFLAGS"
+      fi
+    fi
+    if test -z "$gl_have_pthread"; then
+      case "$gl_use_threads" in
+        yes | windows | win32) # The 'win32' is for backward compatibility.
+          if { case "$host_os" in
+                 mingw*) true;;
+                 *) false;;
+               esac
+             }; then
+            gl_threads_api=windows
+            AC_DEFINE([USE_WINDOWS_THREADS], [1],
+              [Define if the native Windows multithreading API can be used.])
+          fi
+          ;;
+      esac
+    fi
+  fi
+  AC_MSG_CHECKING([for multithread API to use])
+  AC_MSG_RESULT([$gl_threads_api])
+  AC_SUBST([LIBTHREAD])
+  AC_SUBST([LTLIBTHREAD])
+  AC_SUBST([LIBMULTITHREAD])
+  AC_SUBST([LTLIBMULTITHREAD])
+])
+
+AC_DEFUN([gl_THREADLIB],
+[
+  AC_REQUIRE([gl_THREADLIB_EARLY])
+  AC_REQUIRE([gl_THREADLIB_BODY])
+])
+
+
+dnl gl_DISABLE_THREADS
+dnl ------------------
+dnl Sets the gl_THREADLIB default so that threads are not used by default.
+dnl The user can still override it at installation time, by using the
+dnl configure option '--enable-threads'.
+
+AC_DEFUN([gl_DISABLE_THREADS], [
+  m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no])
+])
+
+
+dnl Survey of platforms:
+dnl
+dnl Platform           Available  Compiler    Supports   test-lock
+dnl                    flavours   option      weak       result
+dnl ---------------    ---------  ---------   --------   ---------
+dnl Linux 2.4/glibc    posix      -lpthread       Y      OK
+dnl
+dnl GNU Hurd/glibc     posix
+dnl
+dnl Ubuntu 14.04       posix      -pthread        Y      OK
+dnl
+dnl FreeBSD 5.3        posix      -lc_r           Y
+dnl                    posix      -lkse ?         Y
+dnl                    posix      -lpthread ?     Y
+dnl                    posix      -lthr           Y
+dnl
+dnl FreeBSD 5.2        posix      -lc_r           Y
+dnl                    posix      -lkse           Y
+dnl                    posix      -lthr           Y
+dnl
+dnl FreeBSD 4.0,4.10   posix      -lc_r           Y      OK
+dnl
+dnl NetBSD 1.6         --
+dnl
+dnl OpenBSD 3.4        posix      -lpthread       Y      OK
+dnl
+dnl Mac OS X 10.[123]  posix      -lpthread       Y      OK
+dnl
+dnl Solaris 7,8,9      posix      -lpthread       Y      Sol 7,8: 0.0; Sol 9: OK
+dnl                    solaris    -lthread        Y      Sol 7,8: 0.0; Sol 9: OK
+dnl
+dnl HP-UX 11           posix      -lpthread       N (cc) OK
+dnl                                               Y (gcc)
+dnl
+dnl IRIX 6.5           posix      -lpthread       Y      0.5
+dnl
+dnl AIX 4.3,5.1        posix      -lpthread       N      AIX 4: 0.5; AIX 5: OK
+dnl
+dnl OSF/1 4.0,5.1      posix      -pthread (cc)   N      OK
+dnl                               -lpthread (gcc) Y
+dnl
+dnl Cygwin             posix      -lpthread       Y      OK
+dnl
+dnl Any of the above   pth        -lpth                  0.0
+dnl
+dnl Mingw              windows                    N      OK
+dnl
+dnl BeOS 5             --
+dnl
+dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is
+dnl turned off:
+dnl   OK if all three tests terminate OK,
+dnl   0.5 if the first test terminates OK but the second one loops endlessly,
+dnl   0.0 if the first test already loops endlessly.
diff --git a/gnulib/import/strerror_r.c b/gnulib/import/strerror_r.c
new file mode 100644
index 0000000..b1d4cf5
--- /dev/null
+++ b/gnulib/import/strerror_r.c
@@ -0,0 +1,338 @@ 
+/* strerror_r.c --- POSIX compatible system error routine
+
+   Copyright (C) 2010-2016 Free Software Foundation, Inc.
+
+   This program 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 program 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 program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2010.  */
+
+#include <config.h>
+
+/* Enable declaration of sys_nerr and sys_errlist in <errno.h> on NetBSD.  */
+#define _NETBSD_SOURCE 1
+
+/* Specification.  */
+#include <string.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "strerror-override.h"
+
+#if (__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__) && HAVE___XPG_STRERROR_R /* glibc >= 2.3.4, cygwin >= 1.7.9 */
+
+# define USE_XPG_STRERROR_R 1
+extern
+#ifdef __cplusplus
+"C"
+#endif
+int __xpg_strerror_r (int errnum, char *buf, size_t buflen);
+
+#elif HAVE_DECL_STRERROR_R_ORIG && !(__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__)
+
+/* The system's strerror_r function is OK, except that its third argument
+   is 'int', not 'size_t', or its return type is wrong.  */
+
+# include <limits.h>
+
+# define USE_SYSTEM_STRERROR_R 1
+
+#else /* (__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__ ? !HAVE___XPG_STRERROR_R : !HAVE_DECL_STRERROR_R) */
+
+/* Use the system's strerror().  Exclude glibc and cygwin because the
+   system strerror_r has the wrong return type, and cygwin 1.7.9
+   strerror_r clobbers strerror.  */
+# undef strerror
+
+# define USE_SYSTEM_STRERROR 1
+
+# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __sgi || (defined __sun && !defined _LP64) || defined __CYGWIN__
+
+/* No locking needed.  */
+
+/* Get catgets internationalization functions.  */
+#  if HAVE_CATGETS
+#   include <nl_types.h>
+#  endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Get sys_nerr, sys_errlist on HP-UX (otherwise only declared in C++ mode).
+   Get sys_nerr, sys_errlist on IRIX (otherwise only declared with _SGIAPI).  */
+#  if defined __hpux || defined __sgi
+extern int sys_nerr;
+extern char *sys_errlist[];
+#  endif
+
+/* Get sys_nerr on Solaris.  */
+#  if defined __sun && !defined _LP64
+extern int sys_nerr;
+#  endif
+
+#ifdef __cplusplus
+}
+#endif
+
+# else
+
+#  include "glthread/lock.h"
+
+/* This lock protects the buffer returned by strerror().  We assume that
+   no other uses of strerror() exist in the program.  */
+gl_lock_define_initialized(static, strerror_lock)
+
+# endif
+
+#endif
+
+/* On MSVC, there is no snprintf() function, just a _snprintf().
+   It is of lower quality, but sufficient for the simple use here.
+   We only have to make sure to NUL terminate the result (_snprintf
+   does not NUL terminate, like strncpy).  */
+#if !HAVE_SNPRINTF
+static int
+local_snprintf (char *buf, size_t buflen, const char *format, ...)
+{
+  va_list args;
+  int result;
+
+  va_start (args, format);
+  result = _vsnprintf (buf, buflen, format, args);
+  va_end (args);
+  if (buflen > 0 && (result < 0 || result >= buflen))
+    buf[buflen - 1] = '\0';
+  return result;
+}
+# define snprintf local_snprintf
+#endif
+
+/* Copy as much of MSG into BUF as possible, without corrupting errno.
+   Return 0 if MSG fit in BUFLEN, otherwise return ERANGE.  */
+static int
+safe_copy (char *buf, size_t buflen, const char *msg)
+{
+  size_t len = strlen (msg);
+  int ret;
+
+  if (len < buflen)
+    {
+      /* Although POSIX allows memcpy() to corrupt errno, we don't
+         know of any implementation where this is a real problem.  */
+      memcpy (buf, msg, len + 1);
+      ret = 0;
+    }
+  else
+    {
+      memcpy (buf, msg, buflen - 1);
+      buf[buflen - 1] = '\0';
+      ret = ERANGE;
+    }
+  return ret;
+}
+
+
+int
+strerror_r (int errnum, char *buf, size_t buflen)
+#undef strerror_r
+{
+  /* Filter this out now, so that rest of this replacement knows that
+     there is room for a non-empty message and trailing NUL.  */
+  if (buflen <= 1)
+    {
+      if (buflen)
+        *buf = '\0';
+      return ERANGE;
+    }
+  *buf = '\0';
+
+  /* Check for gnulib overrides.  */
+  {
+    char const *msg = strerror_override (errnum);
+
+    if (msg)
+      return safe_copy (buf, buflen, msg);
+  }
+
+  {
+    int ret;
+    int saved_errno = errno;
+
+#if USE_XPG_STRERROR_R
+
+    {
+      ret = __xpg_strerror_r (errnum, buf, buflen);
+      if (ret < 0)
+        ret = errno;
+      if (!*buf)
+        {
+          /* glibc 2.13 would not touch buf on err, so we have to fall
+             back to GNU strerror_r which always returns a thread-safe
+             untruncated string to (partially) copy into our buf.  */
+          safe_copy (buf, buflen, strerror_r (errnum, buf, buflen));
+        }
+    }
+
+#elif USE_SYSTEM_STRERROR_R
+
+    if (buflen > INT_MAX)
+      buflen = INT_MAX;
+
+# ifdef __hpux
+    /* On HP-UX 11.31, strerror_r always fails when buflen < 80; it
+       also fails to change buf on EINVAL.  */
+    {
+      char stackbuf[80];
+
+      if (buflen < sizeof stackbuf)
+        {
+          ret = strerror_r (errnum, stackbuf, sizeof stackbuf);
+          if (ret == 0)
+            ret = safe_copy (buf, buflen, stackbuf);
+        }
+      else
+        ret = strerror_r (errnum, buf, buflen);
+    }
+# else
+    ret = strerror_r (errnum, buf, buflen);
+
+    /* Some old implementations may return (-1, EINVAL) instead of EINVAL.  */
+    if (ret < 0)
+      ret = errno;
+# endif
+
+# ifdef _AIX
+    /* AIX returns 0 rather than ERANGE when truncating strings; try
+       again until we are sure we got the entire string.  */
+    if (!ret && strlen (buf) == buflen - 1)
+      {
+        char stackbuf[STACKBUF_LEN];
+        size_t len;
+        strerror_r (errnum, stackbuf, sizeof stackbuf);
+        len = strlen (stackbuf);
+        /* STACKBUF_LEN should have been large enough.  */
+        if (len + 1 == sizeof stackbuf)
+          abort ();
+        if (buflen <= len)
+          ret = ERANGE;
+      }
+# else
+    /* Solaris 10 does not populate buf on ERANGE.  OpenBSD 4.7
+       truncates early on ERANGE rather than return a partial integer.
+       We prefer the maximal string.  We set buf[0] earlier, and we
+       know of no implementation that modifies buf to be an
+       unterminated string, so this strlen should be portable in
+       practice (rather than pulling in a safer strnlen).  */
+    if (ret == ERANGE && strlen (buf) < buflen - 1)
+      {
+        char stackbuf[STACKBUF_LEN];
+
+        /* STACKBUF_LEN should have been large enough.  */
+        if (strerror_r (errnum, stackbuf, sizeof stackbuf) == ERANGE)
+          abort ();
+        safe_copy (buf, buflen, stackbuf);
+      }
+# endif
+
+#else /* USE_SYSTEM_STRERROR */
+
+    /* Try to do what strerror (errnum) does, but without clobbering the
+       buffer used by strerror().  */
+
+# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __CYGWIN__ /* NetBSD, HP-UX, native Windows, Cygwin */
+
+    /* NetBSD:         sys_nerr, sys_errlist are declared through _NETBSD_SOURCE
+                       and <errno.h> above.
+       HP-UX:          sys_nerr, sys_errlist are declared explicitly above.
+       native Windows: sys_nerr, sys_errlist are declared in <stdlib.h>.
+       Cygwin:         sys_nerr, sys_errlist are declared in <errno.h>.  */
+    if (errnum >= 0 && errnum < sys_nerr)
+      {
+#  if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
+#   if defined __NetBSD__
+        nl_catd catd = catopen ("libc", NL_CAT_LOCALE);
+        const char *errmsg =
+          (catd != (nl_catd)-1
+           ? catgets (catd, 1, errnum, sys_errlist[errnum])
+           : sys_errlist[errnum]);
+#   endif
+#   if defined __hpux
+        nl_catd catd = catopen ("perror", NL_CAT_LOCALE);
+        const char *errmsg =
+          (catd != (nl_catd)-1
+           ? catgets (catd, 1, 1 + errnum, sys_errlist[errnum])
+           : sys_errlist[errnum]);
+#   endif
+#  else
+        const char *errmsg = sys_errlist[errnum];
+#  endif
+        if (errmsg == NULL || *errmsg == '\0')
+          ret = EINVAL;
+        else
+          ret = safe_copy (buf, buflen, errmsg);
+#  if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
+        if (catd != (nl_catd)-1)
+          catclose (catd);
+#  endif
+      }
+    else
+      ret = EINVAL;
+
+# elif defined __sgi || (defined __sun && !defined _LP64) /* IRIX, Solaris <= 9 32-bit */
+
+    /* For a valid error number, the system's strerror() function returns
+       a pointer to a not copied string, not to a buffer.  */
+    if (errnum >= 0 && errnum < sys_nerr)
+      {
+        char *errmsg = strerror (errnum);
+
+        if (errmsg == NULL || *errmsg == '\0')
+          ret = EINVAL;
+        else
+          ret = safe_copy (buf, buflen, errmsg);
+      }
+    else
+      ret = EINVAL;
+
+# else
+
+    gl_lock_lock (strerror_lock);
+
+    {
+      char *errmsg = strerror (errnum);
+
+      /* For invalid error numbers, strerror() on
+           - IRIX 6.5 returns NULL,
+           - HP-UX 11 returns an empty string.  */
+      if (errmsg == NULL || *errmsg == '\0')
+        ret = EINVAL;
+      else
+        ret = safe_copy (buf, buflen, errmsg);
+    }
+
+    gl_lock_unlock (strerror_lock);
+
+# endif
+
+#endif
+
+    if (ret == EINVAL && !*buf)
+      snprintf (buf, buflen, "Unknown error %d", errnum);
+
+    errno = saved_errno;
+    return ret;
+  }
+}
diff --git a/gnulib/update-gnulib.sh b/gnulib/update-gnulib.sh
index 634676a..db6a115 100755
--- a/gnulib/update-gnulib.sh
+++ b/gnulib/update-gnulib.sh
@@ -55,6 +55,7 @@ 
     setenv \
     signal-h \
     strchrnul \
+    strerror_r-posix \
     strstr \
     strtok_r \
     sys_stat \