diff --git a/gdb/gnulib/aclocal.m4 b/gdb/gnulib/aclocal.m4
index cd0dd5d..a4ce6a6 100644
--- a/gdb/gnulib/aclocal.m4
+++ b/gdb/gnulib/aclocal.m4
@@ -1023,6 +1023,7 @@ m4_include([import/m4/dirfd.m4])
 m4_include([import/m4/dirname.m4])
 m4_include([import/m4/double-slash-root.m4])
 m4_include([import/m4/eealloc.m4])
+m4_include([import/m4/environ.m4])
 m4_include([import/m4/errno_h.m4])
 m4_include([import/m4/exponentd.m4])
 m4_include([import/m4/exponentl.m4])
@@ -1071,6 +1072,7 @@ m4_include([import/m4/rawmemchr.m4])
 m4_include([import/m4/readlink.m4])
 m4_include([import/m4/rename.m4])
 m4_include([import/m4/rmdir.m4])
+m4_include([import/m4/setenv.m4])
 m4_include([import/m4/signal_h.m4])
 m4_include([import/m4/ssize_t.m4])
 m4_include([import/m4/stat.m4])
diff --git a/gdb/gnulib/config.in b/gdb/gnulib/config.in
index 057b12d..6061520 100644
--- a/gdb/gnulib/config.in
+++ b/gdb/gnulib/config.in
@@ -95,6 +95,9 @@
 /* Define to 1 when the gnulib module dirfd should be tested. */
 #undef GNULIB_TEST_DIRFD
 
+/* Define to 1 when the gnulib module environ should be tested. */
+#undef GNULIB_TEST_ENVIRON
+
 /* Define to 1 when the gnulib module frexp should be tested. */
 #undef GNULIB_TEST_FREXP
 
@@ -140,6 +143,9 @@
 /* Define to 1 when the gnulib module rmdir should be tested. */
 #undef GNULIB_TEST_RMDIR
 
+/* Define to 1 when the gnulib module setenv should be tested. */
+#undef GNULIB_TEST_SETENV
+
 /* Define to 1 when the gnulib module stat should be tested. */
 #undef GNULIB_TEST_STAT
 
@@ -152,6 +158,9 @@
 /* Define to 1 when the gnulib module strtok_r should be tested. */
 #undef GNULIB_TEST_STRTOK_R
 
+/* Define to 1 when the gnulib module unsetenv should be tested. */
+#undef GNULIB_TEST_UNSETENV
+
 /* Define to 1 if you have 'alloca' after including <alloca.h>, a header that
    may be supplied by this distribution. */
 #undef HAVE_ALLOCA
@@ -201,6 +210,10 @@
    */
 #undef HAVE_DECL_MEMMEM
 
+/* Define to 1 if you have the declaration of `setenv', and to 0 if you don't.
+   */
+#undef HAVE_DECL_SETENV
+
 /* Define to 1 if you have the declaration of `strtok_r', and to 0 if you
    don't. */
 #undef HAVE_DECL_STRTOK_R
@@ -209,12 +222,19 @@
    don't. */
 #undef HAVE_DECL_TOWLOWER
 
+/* Define to 1 if you have the declaration of `unsetenv', and to 0 if you
+   don't. */
+#undef HAVE_DECL_UNSETENV
+
 /* Define to 1 if you have the <dirent.h> header file. */
 #undef HAVE_DIRENT_H
 
 /* Define to 1 if you have the `dirfd' function. */
 #undef HAVE_DIRFD
 
+/* Define if you have the declaration of environ. */
+#undef HAVE_ENVIRON_DECL
+
 /* Define to 1 if you have the <features.h> header file. */
 #undef HAVE_FEATURES_H
 
@@ -1126,6 +1146,12 @@
 /* Define to 1 if 'long double' and 'double' have the same representation. */
 #undef HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
 
+/* Define to 1 if you have the <search.h> header file. */
+#undef HAVE_SEARCH_H
+
+/* Define to 1 if you have the `setenv' function. */
+#undef HAVE_SETENV
+
 /* Define to 1 if 'sig_atomic_t' is a signed integer type. */
 #undef HAVE_SIGNED_SIG_ATOMIC_T
 
@@ -1189,9 +1215,15 @@
 /* Define to 1 if you have the `towlower' function. */
 #undef HAVE_TOWLOWER
 
+/* Define to 1 if you have the `tsearch' function. */
+#undef HAVE_TSEARCH
+
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
+/* Define to 1 if you have the `unsetenv' function. */
+#undef HAVE_UNSETENV
+
 /* Define to 1 if the system has the type 'unsigned long long int'. */
 #undef HAVE_UNSIGNED_LONG_LONG_INT
 
@@ -1407,6 +1439,9 @@
 #endif
 
 
+/* Define to 1 if unsetenv returns void instead of int. */
+#undef VOID_UNSETENV
+
 /* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
    'wchar_t'. */
 #undef WCHAR_T_SUFFIX
diff --git a/gdb/gnulib/configure b/gdb/gnulib/configure
index d214164..2a0dfc2 100644
--- a/gdb/gnulib/configure
+++ b/gdb/gnulib/configure
@@ -3307,6 +3307,7 @@ as_fn_append ac_func_list " readlink"
 as_fn_append ac_func_list " realpath"
 as_fn_append ac_header_list " sys/param.h"
 as_fn_append ac_header_list " dirent.h"
+as_fn_append ac_header_list " unistd.h"
 as_fn_append ac_func_list " btowc"
 as_fn_append ac_func_list " isblank"
 as_fn_append ac_func_list " iswctype"
@@ -3324,7 +3325,6 @@ as_fn_append ac_header_list " limits.h"
 as_fn_append ac_header_list " wchar.h"
 as_fn_append ac_header_list " stdint.h"
 as_fn_append ac_header_list " inttypes.h"
-as_fn_append ac_header_list " unistd.h"
 as_fn_append ac_func_list " symlink"
 as_fn_append ac_func_list " lstat"
 as_fn_append ac_header_list " math.h"
@@ -3333,6 +3333,7 @@ as_fn_append ac_func_list " mbrtowc"
 as_fn_append ac_header_list " sys/mman.h"
 as_fn_append ac_func_list " mprotect"
 as_fn_append ac_func_list " link"
+as_fn_append ac_func_list " setenv"
 as_fn_append ac_header_list " sys/stat.h"
 as_fn_append ac_header_list " features.h"
 as_fn_append ac_func_list " iswcntrl"
@@ -5311,6 +5312,7 @@ fi
   # Code from module dirname-lgpl:
   # Code from module dosname:
   # Code from module double-slash-root:
+  # Code from module environ:
   # Code from module errno:
   # Code from module extensions:
   # Code from module extern-inline:
@@ -5352,6 +5354,7 @@ fi
   # Code from module rename:
   # Code from module rmdir:
   # Code from module same-inode:
+  # Code from module setenv:
   # Code from module signal-h:
   # Code from module snippet/_Noreturn:
   # Code from module snippet/arg-nonnull:
@@ -5376,6 +5379,7 @@ fi
   # Code from module sys_types:
   # Code from module time:
   # Code from module unistd:
+  # Code from module unsetenv:
   # Code from module update-copyright:
   # Code from module verify:
   # Code from module wchar:
@@ -6826,6 +6830,59 @@ $as_echo "$gl_cv_pragma_columns" >&6; }
 
 
 
+
+
+
+
+
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if environ is properly declared" >&5
+$as_echo_n "checking if environ is properly declared... " >&6; }
+  if test "${gt_cv_var_environ_declaration+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#if HAVE_UNISTD_H
+     #include <unistd.h>
+     #endif
+     /* mingw, BeOS, Haiku declare environ in <stdlib.h>, not in <unistd.h>.  */
+     #include <stdlib.h>
+
+           extern struct { int foo; } environ;
+int
+main ()
+{
+environ.foo = 1;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gt_cv_var_environ_declaration=no
+else
+  gt_cv_var_environ_declaration=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gt_cv_var_environ_declaration" >&5
+$as_echo "$gt_cv_var_environ_declaration" >&6; }
+  if test $gt_cv_var_environ_declaration = yes; then
+
+$as_echo "#define HAVE_ENVIRON_DECL 1" >>confdefs.h
+
+  fi
+
+
+  if test $gt_cv_var_environ_declaration != yes; then
+    HAVE_DECL_ENVIRON=0
+  fi
+
+
+
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for complete errno.h" >&5
 $as_echo_n "checking for complete errno.h... " >&6; }
 if test "${gl_cv_header_errno_h_complete+set}" = set; then :
@@ -9919,8 +9976,6 @@ $as_echo "#define HAVE_LANGINFO_CODESET 1" >>confdefs.h
 
 
 
-
-
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for working fcntl.h" >&5
 $as_echo_n "checking for working fcntl.h... " >&6; }
 if test "${gl_cv_header_working_fcntl_h+set}" = set; then :
@@ -11411,6 +11466,55 @@ $as_echo "$gl_cv_func_memmem_works_always" >&6; }
 
 
 
+ac_fn_c_check_decl "$LINENO" "setenv" "ac_cv_have_decl_setenv" "$ac_includes_default"
+if test "x$ac_cv_have_decl_setenv" = x""yes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_SETENV $ac_have_decl
+_ACEOF
+
+
+
+
+
+
+  if test $ac_cv_have_decl_setenv = no; then
+    HAVE_DECL_SETENV=0
+  fi
+
+
+
+
+
+  for ac_header in search.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "search.h" "ac_cv_header_search_h" "$ac_includes_default"
+if test "x$ac_cv_header_search_h" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_SEARCH_H 1
+_ACEOF
+
+fi
+
+done
+
+  for ac_func in tsearch
+do :
+  ac_fn_c_check_func "$LINENO" "tsearch" "ac_cv_func_tsearch"
+if test "x$ac_cv_func_tsearch" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_TSEARCH 1
+_ACEOF
+
+fi
+done
+
+
+
 
   GNULIB_PTHREAD_SIGMASK=0;
   GNULIB_RAISE=0;
@@ -12246,6 +12350,17 @@ $as_echo "$gl_cv_next_time_h" >&6; }
 
 
 
+ac_fn_c_check_decl "$LINENO" "unsetenv" "ac_cv_have_decl_unsetenv" "$ac_includes_default"
+if test "x$ac_cv_have_decl_unsetenv" = x""yes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_UNSETENV $ac_have_decl
+_ACEOF
+
 
             { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether <wchar.h> uses 'inline' correctly" >&5
 $as_echo_n "checking whether <wchar.h> uses 'inline' correctly... " >&6; }
@@ -12917,6 +13032,22 @@ $as_echo "#define DOUBLE_SLASH_IS_DISTINCT_ROOT 1" >>confdefs.h
 
 
 
+
+
+
+          GNULIB_ENVIRON=1
+
+
+
+
+
+$as_echo "#define GNULIB_TEST_ENVIRON 1" >>confdefs.h
+
+
+
+
+
+
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for flexible array member" >&5
 $as_echo_n "checking for flexible array member... " >&6; }
 if test "${ac_cv_c_flexmember+set}" = set; then :
@@ -17099,6 +17230,102 @@ $as_echo "#define GNULIB_TEST_RMDIR 1" >>confdefs.h
 
 
 
+     if test $ac_cv_func_setenv = no; then
+    HAVE_SETENV=0
+  else
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether setenv validates arguments" >&5
+$as_echo_n "checking whether setenv validates arguments... " >&6; }
+if test "${gl_cv_func_setenv_works+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_setenv_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_setenv_works="guessing no" ;;
+       esac
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+       #include <stdlib.h>
+       #include <errno.h>
+       #include <string.h>
+
+int
+main ()
+{
+
+       int result = 0;
+       {
+         if (setenv ("", "", 0) != -1)
+           result |= 1;
+         else if (errno != EINVAL)
+           result |= 2;
+       }
+       {
+         if (setenv ("a", "=", 1) != 0)
+           result |= 4;
+         else if (strcmp (getenv ("a"), "=") != 0)
+           result |= 8;
+       }
+       return result;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_setenv_works=yes
+else
+  gl_cv_func_setenv_works=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_setenv_works" >&5
+$as_echo "$gl_cv_func_setenv_works" >&6; }
+    case "$gl_cv_func_setenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_SETENV=1
+        ;;
+    esac
+  fi
+
+  if test $HAVE_SETENV = 0 || test $REPLACE_SETENV = 1; then
+
+
+
+
+
+
+
+
+  gl_LIBOBJS="$gl_LIBOBJS setenv.$ac_objext"
+
+  fi
+
+
+
+
+
+          GNULIB_SETENV=1
+
+
+
+
+
+$as_echo "#define GNULIB_TEST_SETENV 1" >>confdefs.h
+
+
+
+
+
 
 
 
@@ -18642,6 +18869,164 @@ fi
 
 
 
+  if test $ac_cv_have_decl_unsetenv = no; then
+    HAVE_DECL_UNSETENV=0
+  fi
+  for ac_func in unsetenv
+do :
+  ac_fn_c_check_func "$LINENO" "unsetenv" "ac_cv_func_unsetenv"
+if test "x$ac_cv_func_unsetenv" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_UNSETENV 1
+_ACEOF
+
+fi
+done
+
+  if test $ac_cv_func_unsetenv = no; then
+    HAVE_UNSETENV=0
+  else
+    HAVE_UNSETENV=1
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for unsetenv() return type" >&5
+$as_echo_n "checking for unsetenv() return type... " >&6; }
+if test "${gt_cv_func_unsetenv_ret+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#undef _BSD
+#define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */
+#include <stdlib.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+int unsetenv (const char *name);
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gt_cv_func_unsetenv_ret='int'
+else
+  gt_cv_func_unsetenv_ret='void'
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gt_cv_func_unsetenv_ret" >&5
+$as_echo "$gt_cv_func_unsetenv_ret" >&6; }
+    if test $gt_cv_func_unsetenv_ret = 'void'; then
+
+$as_echo "#define VOID_UNSETENV 1" >>confdefs.h
+
+      REPLACE_UNSETENV=1
+    fi
+
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether unsetenv obeys POSIX" >&5
+$as_echo_n "checking whether unsetenv obeys POSIX... " >&6; }
+if test "${gl_cv_func_unsetenv_works+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_unsetenv_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_unsetenv_works="guessing no" ;;
+       esac
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+       #include <stdlib.h>
+       #include <errno.h>
+       extern char **environ;
+
+int
+main ()
+{
+
+       char entry1[] = "a=1";
+       char entry2[] = "b=2";
+       char *env[] = { entry1, entry2, NULL };
+       if (putenv ((char *) "a=1")) return 1;
+       if (putenv (entry2)) return 2;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 3;
+       if (!unsetenv ("") || errno != EINVAL) return 4;
+       entry2[0] = 'b';
+       environ = env;
+       if (!getenv ("a")) return 5;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 6;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_unsetenv_works=yes
+else
+  gl_cv_func_unsetenv_works=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_unsetenv_works" >&5
+$as_echo "$gl_cv_func_unsetenv_works" >&6; }
+    case "$gl_cv_func_unsetenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_UNSETENV=1
+        ;;
+    esac
+  fi
+
+  if test $HAVE_UNSETENV = 0 || test $REPLACE_UNSETENV = 1; then
+
+
+
+
+
+
+
+
+  gl_LIBOBJS="$gl_LIBOBJS unsetenv.$ac_objext"
+
+
+
+
+
+  fi
+
+
+
+
+
+          GNULIB_UNSETENV=1
+
+
+
+
+
+$as_echo "#define GNULIB_TEST_UNSETENV 1" >>confdefs.h
+
+
+
+
+
+
 
 
 
diff --git a/gdb/gnulib/import/Makefile.am b/gdb/gnulib/import/Makefile.am
index baa03a5..26f249d 100644
--- a/gdb/gnulib/import/Makefile.am
+++ b/gdb/gnulib/import/Makefile.am
@@ -21,7 +21,7 @@
 # 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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename signal-h strchrnul strstr strtok_r sys_stat unistd 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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename setenv signal-h strchrnul strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
 
 AUTOMAKE_OPTIONS = 1.9.6 gnits
 
@@ -928,6 +928,15 @@ EXTRA_DIST += same-inode.h
 
 ## end   gnulib module same-inode
 
+## begin gnulib module setenv
+
+
+EXTRA_DIST += setenv.c
+
+EXTRA_libgnu_a_SOURCES += setenv.c
+
+## end   gnulib module setenv
+
 ## begin gnulib module signal-h
 
 BUILT_SOURCES += signal.h
@@ -1862,6 +1871,15 @@ EXTRA_DIST += unistd.in.h
 
 ## end   gnulib module unistd
 
+## begin gnulib module unsetenv
+
+
+EXTRA_DIST += unsetenv.c
+
+EXTRA_libgnu_a_SOURCES += unsetenv.c
+
+## end   gnulib module unsetenv
+
 ## begin gnulib module update-copyright
 
 
diff --git a/gdb/gnulib/import/Makefile.in b/gdb/gnulib/import/Makefile.in
index d45d7ea..ca7a73d 100644
--- a/gdb/gnulib/import/Makefile.in
+++ b/gdb/gnulib/import/Makefile.in
@@ -36,7 +36,7 @@
 # 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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename signal-h strchrnul strstr strtok_r sys_stat unistd 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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename setenv signal-h strchrnul strstr strtok_r sys_stat unistd unsetenv update-copyright wchar wctype-h
 
 
 
@@ -74,6 +74,7 @@ am__aclocal_m4_deps = $(top_srcdir)/import/m4/00gnulib.m4 \
 	$(top_srcdir)/import/m4/dirname.m4 \
 	$(top_srcdir)/import/m4/double-slash-root.m4 \
 	$(top_srcdir)/import/m4/eealloc.m4 \
+	$(top_srcdir)/import/m4/environ.m4 \
 	$(top_srcdir)/import/m4/errno_h.m4 \
 	$(top_srcdir)/import/m4/exponentd.m4 \
 	$(top_srcdir)/import/m4/exponentl.m4 \
@@ -122,6 +123,7 @@ am__aclocal_m4_deps = $(top_srcdir)/import/m4/00gnulib.m4 \
 	$(top_srcdir)/import/m4/readlink.m4 \
 	$(top_srcdir)/import/m4/rename.m4 \
 	$(top_srcdir)/import/m4/rmdir.m4 \
+	$(top_srcdir)/import/m4/setenv.m4 \
 	$(top_srcdir)/import/m4/signal_h.m4 \
 	$(top_srcdir)/import/m4/ssize_t.m4 \
 	$(top_srcdir)/import/m4/stat.m4 \
@@ -1289,7 +1291,7 @@ EXTRA_DIST = m4/gnulib-cache.m4 alloca.c alloca.in.h \
 	mbrtowc.c mbsinit.c mbsrtowcs-impl.h mbsrtowcs-state.c \
 	mbsrtowcs.c memchr.c memchr.valgrind memmem.c str-two-way.h \
 	pathmax.h rawmemchr.c rawmemchr.valgrind readlink.c rename.c \
-	rmdir.c same-inode.h signal.in.h \
+	rmdir.c same-inode.h 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 \
@@ -1297,7 +1299,7 @@ EXTRA_DIST = m4/gnulib-cache.m4 alloca.c alloca.in.h \
 	stdbool.in.h stddef.in.h stdint.in.h stdio.in.h stdlib.in.h \
 	strchrnul.c strchrnul.valgrind streq.h string.in.h \
 	str-two-way.h strstr.c strtok_r.c sys_stat.in.h sys_time.in.h \
-	sys_types.in.h time.in.h unistd.in.h \
+	sys_types.in.h time.in.h unistd.in.h unsetenv.c \
 	$(top_srcdir)/import/extra/update-copyright verify.h \
 	wchar.in.h wctype.in.h
 
@@ -1343,7 +1345,7 @@ EXTRA_libgnu_a_SOURCES = alloca.c canonicalize-lgpl.c dirfd.c float.c \
 	gettimeofday.c isnan.c isnand.c isnan.c isnanl.c lstat.c \
 	malloc.c mbrtowc.c mbsinit.c mbsrtowcs-state.c mbsrtowcs.c \
 	memchr.c memmem.c rawmemchr.c readlink.c rename.c rmdir.c \
-	stat.c strchrnul.c strstr.c strtok_r.c
+	setenv.c stat.c strchrnul.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
@@ -1449,6 +1451,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/readlink.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/rename.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/rmdir.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/setenv.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stat.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strchrnul.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stripslash.Po@am__quote@
@@ -1456,6 +1459,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strstr.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/strtok_r.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(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@
 
 .c.o:
diff --git a/gdb/gnulib/import/m4/environ.m4 b/gdb/gnulib/import/m4/environ.m4
new file mode 100644
index 0000000..9a0ea7e
--- /dev/null
+++ b/gdb/gnulib/import/m4/environ.m4
@@ -0,0 +1,47 @@
+# environ.m4 serial 6
+dnl Copyright (C) 2001-2004, 2006-2016 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_ONCE([gl_ENVIRON],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  dnl Persuade glibc <unistd.h> to declare environ.
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_HEADERS_ONCE([unistd.h])
+  gt_CHECK_VAR_DECL(
+    [#if HAVE_UNISTD_H
+     #include <unistd.h>
+     #endif
+     /* mingw, BeOS, Haiku declare environ in <stdlib.h>, not in <unistd.h>.  */
+     #include <stdlib.h>
+    ],
+    [environ])
+  if test $gt_cv_var_environ_declaration != yes; then
+    HAVE_DECL_ENVIRON=0
+  fi
+])
+
+# Check if a variable is properly declared.
+# gt_CHECK_VAR_DECL(includes,variable)
+AC_DEFUN([gt_CHECK_VAR_DECL],
+[
+  define([gt_cv_var], [gt_cv_var_]$2[_declaration])
+  AC_MSG_CHECKING([if $2 is properly declared])
+  AC_CACHE_VAL([gt_cv_var], [
+    AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[$1
+           extern struct { int foo; } $2;]],
+         [[$2.foo = 1;]])],
+      [gt_cv_var=no],
+      [gt_cv_var=yes])])
+  AC_MSG_RESULT([$gt_cv_var])
+  if test $gt_cv_var = yes; then
+    AC_DEFINE([HAVE_]m4_translit($2, [a-z], [A-Z])[_DECL], 1,
+              [Define if you have the declaration of $2.])
+  fi
+  undefine([gt_cv_var])
+])
diff --git a/gdb/gnulib/import/m4/gnulib-cache.m4 b/gdb/gnulib/import/m4/gnulib-cache.m4
index f99e59b..c4ebb73 100644
--- a/gdb/gnulib/import/m4/gnulib-cache.m4
+++ b/gdb/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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename signal-h strchrnul strstr strtok_r sys_stat unistd 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 inttypes limits-h lstat memchr memmem pathmax rawmemchr readlink rename setenv signal-h strchrnul 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([])
@@ -48,12 +48,14 @@ gl_MODULES([
   rawmemchr
   readlink
   rename
+  setenv
   signal-h
   strchrnul
   strstr
   strtok_r
   sys_stat
   unistd
+  unsetenv
   update-copyright
   wchar
   wctype-h
diff --git a/gdb/gnulib/import/m4/gnulib-comp.m4 b/gdb/gnulib/import/m4/gnulib-comp.m4
index 42d04ed..5a36567 100644
--- a/gdb/gnulib/import/m4/gnulib-comp.m4
+++ b/gdb/gnulib/import/m4/gnulib-comp.m4
@@ -53,6 +53,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module dirname-lgpl:
   # Code from module dosname:
   # Code from module double-slash-root:
+  # Code from module environ:
   # Code from module errno:
   # Code from module extensions:
   # Code from module extern-inline:
@@ -94,6 +95,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module rename:
   # Code from module rmdir:
   # Code from module same-inode:
+  # Code from module setenv:
   # Code from module signal-h:
   # Code from module snippet/_Noreturn:
   # Code from module snippet/arg-nonnull:
@@ -118,6 +120,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module sys_types:
   # Code from module time:
   # Code from module unistd:
+  # Code from module unsetenv:
   # Code from module update-copyright:
   # Code from module verify:
   # Code from module wchar:
@@ -160,6 +163,8 @@ AC_DEFUN([gl_INIT],
   gl_DIRENT_MODULE_INDICATOR([dirfd])
   gl_DIRNAME_LGPL
   gl_DOUBLE_SLASH_ROOT
+  gl_ENVIRON
+  gl_UNISTD_MODULE_INDICATOR([environ])
   gl_HEADER_ERRNO_H
   AC_REQUIRE([gl_EXTERN_INLINE])
   AC_C_FLEXIBLE_ARRAY_MEMBER
@@ -285,6 +290,11 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([rmdir])
   fi
   gl_UNISTD_MODULE_INDICATOR([rmdir])
+  gl_FUNC_SETENV
+  if test $HAVE_SETENV = 0 || test $REPLACE_SETENV = 1; then
+    AC_LIBOBJ([setenv])
+  fi
+  gl_STDLIB_MODULE_INDICATOR([setenv])
   gl_SIGNAL_H
   gt_TYPE_SSIZE_T
   gl_FUNC_STAT
@@ -328,6 +338,12 @@ AC_DEFUN([gl_INIT],
   AC_PROG_MKDIR_P
   gl_HEADER_TIME_H
   gl_UNISTD_H
+  gl_FUNC_UNSETENV
+  if test $HAVE_UNSETENV = 0 || test $REPLACE_UNSETENV = 1; then
+    AC_LIBOBJ([unsetenv])
+    gl_PREREQ_UNSETENV
+  fi
+  gl_STDLIB_MODULE_INDICATOR([unsetenv])
   gl_WCHAR_H
   gl_WCTYPE_H
   # End of code from modules
@@ -533,6 +549,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/rename.c
   lib/rmdir.c
   lib/same-inode.h
+  lib/setenv.c
   lib/signal.in.h
   lib/stat.c
   lib/stdbool.in.h
@@ -556,6 +573,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/time.in.h
   lib/unistd.c
   lib/unistd.in.h
+  lib/unsetenv.c
   lib/verify.h
   lib/wchar.in.h
   lib/wctype-h.c
@@ -571,6 +589,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/dirname.m4
   m4/double-slash-root.m4
   m4/eealloc.m4
+  m4/environ.m4
   m4/errno_h.m4
   m4/exponentd.m4
   m4/exponentl.m4
@@ -618,6 +637,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/readlink.m4
   m4/rename.m4
   m4/rmdir.m4
+  m4/setenv.m4
   m4/signal_h.m4
   m4/ssize_t.m4
   m4/stat.m4
diff --git a/gdb/gnulib/import/m4/setenv.m4 b/gdb/gnulib/import/m4/setenv.m4
new file mode 100644
index 0000000..5d49aba
--- /dev/null
+++ b/gdb/gnulib/import/m4/setenv.m4
@@ -0,0 +1,160 @@
+# setenv.m4 serial 26
+dnl Copyright (C) 2001-2004, 2006-2016 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_SETENV],
+[
+  AC_REQUIRE([gl_FUNC_SETENV_SEPARATE])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  if test $ac_cv_func_setenv = no; then
+    HAVE_SETENV=0
+  else
+    AC_CACHE_CHECK([whether setenv validates arguments],
+      [gl_cv_func_setenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+       #include <errno.h>
+       #include <string.h>
+      ]], [[
+       int result = 0;
+       {
+         if (setenv ("", "", 0) != -1)
+           result |= 1;
+         else if (errno != EINVAL)
+           result |= 2;
+       }
+       {
+         if (setenv ("a", "=", 1) != 0)
+           result |= 4;
+         else if (strcmp (getenv ("a"), "=") != 0)
+           result |= 8;
+       }
+       return result;
+      ]])],
+      [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no],
+      [case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_setenv_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_setenv_works="guessing no" ;;
+       esac
+      ])])
+    case "$gl_cv_func_setenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_SETENV=1
+        ;;
+    esac
+  fi
+])
+
+# Like gl_FUNC_SETENV, except prepare for separate compilation
+# (no REPLACE_SETENV, no AC_LIBOBJ).
+AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([setenv])
+  if test $ac_cv_have_decl_setenv = no; then
+    HAVE_DECL_SETENV=0
+  fi
+  AC_CHECK_FUNCS_ONCE([setenv])
+  gl_PREREQ_SETENV
+])
+
+AC_DEFUN([gl_FUNC_UNSETENV],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CHECK_DECLS_ONCE([unsetenv])
+  if test $ac_cv_have_decl_unsetenv = no; then
+    HAVE_DECL_UNSETENV=0
+  fi
+  AC_CHECK_FUNCS([unsetenv])
+  if test $ac_cv_func_unsetenv = no; then
+    HAVE_UNSETENV=0
+  else
+    HAVE_UNSETENV=1
+    dnl Some BSDs return void, failing to do error checking.
+    AC_CACHE_CHECK([for unsetenv() return type], [gt_cv_func_unsetenv_ret],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[
+#undef _BSD
+#define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */
+#include <stdlib.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+int unsetenv (const char *name);
+            ]],
+            [[]])],
+         [gt_cv_func_unsetenv_ret='int'],
+         [gt_cv_func_unsetenv_ret='void'])])
+    if test $gt_cv_func_unsetenv_ret = 'void'; then
+      AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void
+       instead of int.])
+      REPLACE_UNSETENV=1
+    fi
+
+    dnl Solaris 10 unsetenv does not remove all copies of a name.
+    dnl Haiku alpha 2 unsetenv gets confused by assignment to environ.
+    dnl OpenBSD 4.7 unsetenv("") does not fail.
+    AC_CACHE_CHECK([whether unsetenv obeys POSIX],
+      [gl_cv_func_unsetenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+       #include <errno.h>
+       extern char **environ;
+      ]], [[
+       char entry1[] = "a=1";
+       char entry2[] = "b=2";
+       char *env[] = { entry1, entry2, NULL };
+       if (putenv ((char *) "a=1")) return 1;
+       if (putenv (entry2)) return 2;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 3;
+       if (!unsetenv ("") || errno != EINVAL) return 4;
+       entry2[0] = 'b';
+       environ = env;
+       if (!getenv ("a")) return 5;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 6;
+      ]])],
+      [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
+      [case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_unsetenv_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_unsetenv_works="guessing no" ;;
+       esac
+      ])])
+    case "$gl_cv_func_unsetenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_UNSETENV=1
+        ;;
+    esac
+  fi
+])
+
+# Prerequisites of lib/setenv.c.
+AC_DEFUN([gl_PREREQ_SETENV],
+[
+  AC_REQUIRE([AC_FUNC_ALLOCA])
+  AC_REQUIRE([gl_ENVIRON])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
+  AC_CHECK_HEADERS([search.h])
+  AC_CHECK_FUNCS([tsearch])
+])
+
+# Prerequisites of lib/unsetenv.c.
+AC_DEFUN([gl_PREREQ_UNSETENV],
+[
+  AC_REQUIRE([gl_ENVIRON])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
+])
diff --git a/gdb/gnulib/import/setenv.c b/gdb/gnulib/import/setenv.c
new file mode 100644
index 0000000..85c32cb
--- /dev/null
+++ b/gdb/gnulib/import/setenv.c
@@ -0,0 +1,390 @@
+/* Copyright (C) 1992, 1995-2003, 2005-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#if !_LIBC
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+# define _GL_ARG_NONNULL(params)
+
+# define _GL_USE_STDLIB_ALLOC 1
+# include <config.h>
+#endif
+
+#include <alloca.h>
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(ev) ((errno) = (ev))
+#endif
+
+#include <string.h>
+#if _LIBC || HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#if !_LIBC
+# include "malloca.h"
+#endif
+
+#if _LIBC || !HAVE_SETENV
+
+#if !_LIBC
+# define __environ      environ
+#endif
+
+#if _LIBC
+/* This lock protects against simultaneous modifications of 'environ'.  */
+# include <bits/libc-lock.h>
+__libc_lock_define_initialized (static, envlock)
+# define LOCK   __libc_lock_lock (envlock)
+# define UNLOCK __libc_lock_unlock (envlock)
+#else
+# define LOCK
+# define UNLOCK
+#endif
+
+/* In the GNU C library we must keep the namespace clean.  */
+#ifdef _LIBC
+# define setenv __setenv
+# define clearenv __clearenv
+# define tfind __tfind
+# define tsearch __tsearch
+#endif
+
+/* In the GNU C library implementation we try to be more clever and
+   allow arbitrarily many changes of the environment given that the used
+   values are from a small set.  Outside glibc this will eat up all
+   memory after a while.  */
+#if defined _LIBC || (defined HAVE_SEARCH_H && defined HAVE_TSEARCH \
+                      && defined __GNUC__)
+# define USE_TSEARCH    1
+# include <search.h>
+typedef int (*compar_fn_t) (const void *, const void *);
+
+/* This is a pointer to the root of the search tree with the known
+   values.  */
+static void *known_values;
+
+# define KNOWN_VALUE(Str) \
+  ({                                                                          \
+    void *value = tfind (Str, &known_values, (compar_fn_t) strcmp);           \
+    value != NULL ? *(char **) value : NULL;                                  \
+  })
+# define STORE_VALUE(Str) \
+  tsearch (Str, &known_values, (compar_fn_t) strcmp)
+
+#else
+# undef USE_TSEARCH
+
+# define KNOWN_VALUE(Str) NULL
+# define STORE_VALUE(Str) do { } while (0)
+
+#endif
+
+
+/* If this variable is not a null pointer we allocated the current
+   environment.  */
+static char **last_environ;
+
+
+/* This function is used by 'setenv' and 'putenv'.  The difference between
+   the two functions is that for the former must create a new string which
+   is then placed in the environment, while the argument of 'putenv'
+   must be used directly.  This is all complicated by the fact that we try
+   to reuse values once generated for a 'setenv' call since we can never
+   free the strings.  */
+int
+__add_to_environ (const char *name, const char *value, const char *combined,
+                  int replace)
+{
+  char **ep;
+  size_t size;
+  const size_t namelen = strlen (name);
+  const size_t vallen = value != NULL ? strlen (value) + 1 : 0;
+
+  LOCK;
+
+  /* We have to get the pointer now that we have the lock and not earlier
+     since another thread might have created a new environment.  */
+  ep = __environ;
+
+  size = 0;
+  if (ep != NULL)
+    {
+      for (; *ep != NULL; ++ep)
+        if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
+          break;
+        else
+          ++size;
+    }
+
+  if (ep == NULL || *ep == NULL)
+    {
+      char **new_environ;
+#ifdef USE_TSEARCH
+      char *new_value;
+#endif
+
+      /* We allocated this space; we can extend it.  */
+      new_environ =
+        (char **) (last_environ == NULL
+                   ? malloc ((size + 2) * sizeof (char *))
+                   : realloc (last_environ, (size + 2) * sizeof (char *)));
+      if (new_environ == NULL)
+        {
+          /* It's easier to set errno to ENOMEM than to rely on the
+             'malloc-posix' and 'realloc-posix' gnulib modules.  */
+          __set_errno (ENOMEM);
+          UNLOCK;
+          return -1;
+        }
+
+      /* If the whole entry is given add it.  */
+      if (combined != NULL)
+        /* We must not add the string to the search tree since it belongs
+           to the user.  */
+        new_environ[size] = (char *) combined;
+      else
+        {
+          /* See whether the value is already known.  */
+#ifdef USE_TSEARCH
+# ifdef _LIBC
+          new_value = (char *) alloca (namelen + 1 + vallen);
+          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
+                     value, vallen);
+# else
+          new_value = (char *) malloca (namelen + 1 + vallen);
+          if (new_value == NULL)
+            {
+              __set_errno (ENOMEM);
+              UNLOCK;
+              return -1;
+            }
+          memcpy (new_value, name, namelen);
+          new_value[namelen] = '=';
+          memcpy (&new_value[namelen + 1], value, vallen);
+# endif
+
+          new_environ[size] = KNOWN_VALUE (new_value);
+          if (new_environ[size] == NULL)
+#endif
+            {
+              new_environ[size] = (char *) malloc (namelen + 1 + vallen);
+              if (new_environ[size] == NULL)
+                {
+#if defined USE_TSEARCH && !defined _LIBC
+                  freea (new_value);
+#endif
+                  __set_errno (ENOMEM);
+                  UNLOCK;
+                  return -1;
+                }
+
+#ifdef USE_TSEARCH
+              memcpy (new_environ[size], new_value, namelen + 1 + vallen);
+#else
+              memcpy (new_environ[size], name, namelen);
+              new_environ[size][namelen] = '=';
+              memcpy (&new_environ[size][namelen + 1], value, vallen);
+#endif
+              /* And save the value now.  We cannot do this when we remove
+                 the string since then we cannot decide whether it is a
+                 user string or not.  */
+              STORE_VALUE (new_environ[size]);
+            }
+#if defined USE_TSEARCH && !defined _LIBC
+          freea (new_value);
+#endif
+        }
+
+      if (__environ != last_environ)
+        memcpy ((char *) new_environ, (char *) __environ,
+                size * sizeof (char *));
+
+      new_environ[size + 1] = NULL;
+
+      last_environ = __environ = new_environ;
+    }
+  else if (replace)
+    {
+      char *np;
+
+      /* Use the user string if given.  */
+      if (combined != NULL)
+        np = (char *) combined;
+      else
+        {
+#ifdef USE_TSEARCH
+          char *new_value;
+# ifdef _LIBC
+          new_value = alloca (namelen + 1 + vallen);
+          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
+                     value, vallen);
+# else
+          new_value = malloca (namelen + 1 + vallen);
+          if (new_value == NULL)
+            {
+              __set_errno (ENOMEM);
+              UNLOCK;
+              return -1;
+            }
+          memcpy (new_value, name, namelen);
+          new_value[namelen] = '=';
+          memcpy (&new_value[namelen + 1], value, vallen);
+# endif
+
+          np = KNOWN_VALUE (new_value);
+          if (np == NULL)
+#endif
+            {
+              np = (char *) malloc (namelen + 1 + vallen);
+              if (np == NULL)
+                {
+#if defined USE_TSEARCH && !defined _LIBC
+                  freea (new_value);
+#endif
+                  __set_errno (ENOMEM);
+                  UNLOCK;
+                  return -1;
+                }
+
+#ifdef USE_TSEARCH
+              memcpy (np, new_value, namelen + 1 + vallen);
+#else
+              memcpy (np, name, namelen);
+              np[namelen] = '=';
+              memcpy (&np[namelen + 1], value, vallen);
+#endif
+              /* And remember the value.  */
+              STORE_VALUE (np);
+            }
+#if defined USE_TSEARCH && !defined _LIBC
+          freea (new_value);
+#endif
+        }
+
+      *ep = np;
+    }
+
+  UNLOCK;
+
+  return 0;
+}
+
+int
+setenv (const char *name, const char *value, int replace)
+{
+  if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return __add_to_environ (name, value, NULL, replace);
+}
+
+/* The 'clearenv' was planned to be added to POSIX.1 but probably
+   never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
+   for Fortran 77) requires this function.  */
+int
+clearenv (void)
+{
+  LOCK;
+
+  if (__environ == last_environ && __environ != NULL)
+    {
+      /* We allocated this environment so we can free it.  */
+      free (__environ);
+      last_environ = NULL;
+    }
+
+  /* Clear the environment pointer removes the whole environment.  */
+  __environ = NULL;
+
+  UNLOCK;
+
+  return 0;
+}
+
+#ifdef _LIBC
+static void
+free_mem (void)
+{
+  /* Remove all traces.  */
+  clearenv ();
+
+  /* Now remove the search tree.  */
+  __tdestroy (known_values, free);
+  known_values = NULL;
+}
+text_set_element (__libc_subfreeres, free_mem);
+
+
+# undef setenv
+# undef clearenv
+weak_alias (__setenv, setenv)
+weak_alias (__clearenv, clearenv)
+#endif
+
+#endif /* _LIBC || !HAVE_SETENV */
+
+/* The rest of this file is called into use when replacing an existing
+   but buggy setenv.  Known bugs include failure to diagnose invalid
+   name, and consuming a leading '=' from value.  */
+#if HAVE_SETENV
+
+# undef setenv
+# if !HAVE_DECL_SETENV
+extern int setenv (const char *, const char *, int);
+# endif
+# define STREQ(a, b) (strcmp (a, b) == 0)
+
+int
+rpl_setenv (const char *name, const char *value, int replace)
+{
+  int result;
+  if (!name || !*name || strchr (name, '='))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  /* Call the real setenv even if replace is 0, in case implementation
+     has underlying data to update, such as when environ changes.  */
+  result = setenv (name, value, replace);
+  if (result == 0 && replace && *value == '=')
+    {
+      char *tmp = getenv (name);
+      if (!STREQ (tmp, value))
+        {
+          int saved_errno;
+          size_t len = strlen (value);
+          tmp = malloca (len + 2);
+          /* Since leading '=' is eaten, double it up.  */
+          *tmp = '=';
+          memcpy (tmp + 1, value, len + 1);
+          result = setenv (name, tmp, replace);
+          saved_errno = errno;
+          freea (tmp);
+          errno = saved_errno;
+        }
+    }
+  return result;
+}
+
+#endif /* HAVE_SETENV */
diff --git a/gdb/gnulib/import/unsetenv.c b/gdb/gnulib/import/unsetenv.c
new file mode 100644
index 0000000..8368744
--- /dev/null
+++ b/gdb/gnulib/import/unsetenv.c
@@ -0,0 +1,127 @@
+/* Copyright (C) 1992, 1995-2002, 2005-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+#define _GL_ARG_NONNULL(params)
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <errno.h>
+#if !_LIBC
+# define __set_errno(ev) ((errno) = (ev))
+#endif
+
+#include <string.h>
+#include <unistd.h>
+
+#if !_LIBC
+# define __environ      environ
+#endif
+
+#if _LIBC
+/* This lock protects against simultaneous modifications of 'environ'.  */
+# include <bits/libc-lock.h>
+__libc_lock_define_initialized (static, envlock)
+# define LOCK   __libc_lock_lock (envlock)
+# define UNLOCK __libc_lock_unlock (envlock)
+#else
+# define LOCK
+# define UNLOCK
+#endif
+
+/* In the GNU C library we must keep the namespace clean.  */
+#ifdef _LIBC
+# define unsetenv __unsetenv
+#endif
+
+#if _LIBC || !HAVE_UNSETENV
+
+int
+unsetenv (const char *name)
+{
+  size_t len;
+  char **ep;
+
+  if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  len = strlen (name);
+
+  LOCK;
+
+  ep = __environ;
+  while (*ep != NULL)
+    if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
+      {
+        /* Found it.  Remove this pointer by moving later ones back.  */
+        char **dp = ep;
+
+        do
+          dp[0] = dp[1];
+        while (*dp++);
+        /* Continue the loop in case NAME appears again.  */
+      }
+    else
+      ++ep;
+
+  UNLOCK;
+
+  return 0;
+}
+
+#ifdef _LIBC
+# undef unsetenv
+weak_alias (__unsetenv, unsetenv)
+#endif
+
+#else /* HAVE_UNSETENV */
+
+# undef unsetenv
+# if !HAVE_DECL_UNSETENV
+#  if VOID_UNSETENV
+extern void unsetenv (const char *);
+#  else
+extern int unsetenv (const char *);
+#  endif
+# endif
+
+/* Call the underlying unsetenv, in case there is hidden bookkeeping
+   that needs updating beyond just modifying environ.  */
+int
+rpl_unsetenv (const char *name)
+{
+  int result = 0;
+  if (!name || !*name || strchr (name, '='))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  while (getenv (name))
+# if !VOID_UNSETENV
+    result =
+# endif
+      unsetenv (name);
+  return result;
+}
+
+#endif /* HAVE_UNSETENV */
diff --git a/gdb/gnulib/update-gnulib.sh b/gdb/gnulib/update-gnulib.sh
index 19d949b..2775dc7 100755
--- a/gdb/gnulib/update-gnulib.sh
+++ b/gdb/gnulib/update-gnulib.sh
@@ -46,12 +46,14 @@ IMPORTED_GNULIB_MODULES="\
     rawmemchr \
     readlink \
     rename \
+    setenv \
     signal-h \
     strchrnul \
     strstr \
     strtok_r \
     sys_stat \
     unistd \
+    unsetenv \
     update-copyright \
     wchar \
     wctype-h \
