Added unsetenv and setenv from gnulib

12 files changed, 1039 insertions, 2 deletions

diff --git a/gl/Makefile.am b/gl/Makefile.am
index 2f5f9c4..41a370b 100644
--- a/gl/Makefile.am
+++ b/gl/Makefile.am
@@ -9,7 +9,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=gl --m4-base=gl/m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-libtool --macro-prefix=gl --no-vc-files base64 crypto/sha1 dirname floorf fsusage getaddrinfo gethostname getloadavg getopt gettext mountlist regex strsep timegm vasprintf vsnprintf
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=gl --m4-base=gl/m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-libtool --macro-prefix=gl --no-vc-files base64 crypto/sha1 dirname floorf fsusage getaddrinfo gethostname getloadavg getopt gettext mountlist regex setenv strsep timegm unsetenv vasprintf vsnprintf
 
 AUTOMAKE_OPTIONS = 1.5 gnits
 
@@ -678,6 +678,14 @@ EXTRA_libgnu_a_SOURCES += malloc.c
 
 ## end   gnulib module malloc-posix
 
+## begin gnulib module malloca
+
+libgnu_a_SOURCES += malloca.c
+
+EXTRA_DIST += malloca.h malloca.valgrind
+
+## end   gnulib module malloca
+
 ## begin gnulib module math
 
 BUILT_SOURCES += math.h
@@ -928,6 +936,15 @@ EXTRA_libgnu_a_SOURCES += safe-write.c
 
 ## end   gnulib module safe-write
 
+## begin gnulib module setenv
+
+
+EXTRA_DIST += setenv.c
+
+EXTRA_libgnu_a_SOURCES += setenv.c
+
+## end   gnulib module setenv
+
 ## begin gnulib module size_max
 
 libgnu_a_SOURCES += size_max.h
@@ -1683,6 +1700,15 @@ EXTRA_libgnu_a_SOURCES += dup-safer.c fd-safer.c pipe-safer.c
 
 ## end   gnulib module unistd-safer
 
+## begin gnulib module unsetenv
+
+
+EXTRA_DIST += unsetenv.c
+
+EXTRA_libgnu_a_SOURCES += unsetenv.c
+
+## end   gnulib module unsetenv
+
 ## begin gnulib module vasnprintf
 
 
diff --git a/gl/m4/eealloc.m4 b/gl/m4/eealloc.m4
new file mode 100644
index 0000000..63dd920
--- /dev/null
+++ b/gl/m4/eealloc.m4
@@ -0,0 +1,32 @@
+# eealloc.m4 serial 2
+dnl Copyright (C) 2003, 2009, 2010 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_EEALLOC],
+[
+  AC_REQUIRE([gl_EEMALLOC])
+  AC_REQUIRE([gl_EEREALLOC])
+  AC_REQUIRE([AC_C_INLINE])
+])
+
+AC_DEFUN([gl_EEMALLOC],
+[
+  _AC_FUNC_MALLOC_IF(
+    [gl_cv_func_malloc_0_nonnull=1],
+    [gl_cv_func_malloc_0_nonnull=0])
+  AC_DEFINE_UNQUOTED([MALLOC_0_IS_NONNULL], [$gl_cv_func_malloc_0_nonnull],
+    [If malloc(0) is != NULL, define this to 1.  Otherwise define this
+     to 0.])
+])
+
+AC_DEFUN([gl_EEREALLOC],
+[
+  _AC_FUNC_REALLOC_IF(
+    [gl_cv_func_realloc_0_nonnull=1],
+    [gl_cv_func_realloc_0_nonnull=0])
+  AC_DEFINE_UNQUOTED([REALLOC_0_IS_NONNULL], [$gl_cv_func_realloc_0_nonnull],
+    [If realloc(NULL,0) is != NULL, define this to 1.  Otherwise define this
+     to 0.])
+])
diff --git a/gl/m4/environ.m4 b/gl/m4/environ.m4
new file mode 100644
index 0000000..4c6849a
--- /dev/null
+++ b/gl/m4/environ.m4
@@ -0,0 +1,36 @@
+# environ.m4 serial 4
+dnl Copyright (C) 2001-2004, 2006-2010 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])
+  gt_CHECK_VAR_DECL([#include <unistd.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_TRY_COMPILE([$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/gl/m4/gnulib-cache.m4 b/gl/m4/gnulib-cache.m4
index f23cb51..22e6133 100644
--- a/gl/m4/gnulib-cache.m4
+++ b/gl/m4/gnulib-cache.m4
@@ -15,7 +15,7 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --lib=libgnu --source-base=gl --m4-base=gl/m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-libtool --macro-prefix=gl --no-vc-files base64 crypto/sha1 dirname floorf fsusage getaddrinfo gethostname getloadavg getopt gettext mountlist regex strsep timegm vasprintf vsnprintf
+#   gnulib-tool --import --dir=. --lib=libgnu --source-base=gl --m4-base=gl/m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-libtool --macro-prefix=gl --no-vc-files base64 crypto/sha1 dirname floorf fsusage getaddrinfo gethostname getloadavg getopt gettext mountlist regex setenv strsep timegm unsetenv vasprintf vsnprintf
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])
@@ -32,8 +32,10 @@ gl_MODULES([
   gettext
   mountlist
   regex
+  setenv
   strsep
   timegm
+  unsetenv
   vasprintf
   vsnprintf
 ])
diff --git a/gl/m4/gnulib-comp.m4 b/gl/m4/gnulib-comp.m4
index 73e6365..fc3f353 100644
--- a/gl/m4/gnulib-comp.m4
+++ b/gl/m4/gnulib-comp.m4
@@ -41,6 +41,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module dirname-lgpl:
   # Code from module double-slash-root:
   # Code from module dup2:
+  # Code from module environ:
   # Code from module errno:
   # Code from module error:
   # Code from module exitfail:
@@ -74,6 +75,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module locale:
   # Code from module malloc:
   # Code from module malloc-posix:
+  # Code from module malloca:
   # Code from module math:
   # Code from module mbrtowc:
   # Code from module mbsinit:
@@ -89,6 +91,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module safe-read:
   # Code from module safe-write:
   # Code from module servent:
+  # Code from module setenv:
   # Code from module size_max:
   # Code from module snprintf:
   # Code from module sockets:
@@ -115,6 +118,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module timegm:
   # Code from module unistd:
   # Code from module unistd-safer:
+  # Code from module unsetenv:
   # Code from module vasnprintf:
   # Code from module vasprintf:
   # Code from module verify:
@@ -178,6 +182,9 @@ AC_DEFUN([gl_INIT],
   # Code from module dup2:
   gl_FUNC_DUP2
   gl_UNISTD_MODULE_INDICATOR([dup2])
+  # Code from module environ:
+  gl_ENVIRON
+  gl_UNISTD_MODULE_INDICATOR([environ])
   # Code from module errno:
   gl_HEADER_ERRNO_H
   # Code from module error:
@@ -252,6 +259,8 @@ AC_DEFUN([gl_INIT],
   # Code from module malloc-posix:
   gl_FUNC_MALLOC_POSIX
   gl_STDLIB_MODULE_INDICATOR([malloc-posix])
+  # Code from module malloca:
+  gl_MALLOCA
   # Code from module math:
   gl_MATH_H
   # Code from module mbrtowc:
@@ -289,6 +298,9 @@ AC_DEFUN([gl_INIT],
   gl_SAFE_WRITE
   # Code from module servent:
   gl_SERVENT
+  # Code from module setenv:
+  gl_FUNC_SETENV
+  gl_STDLIB_MODULE_INDICATOR([setenv])
   # Code from module size_max:
   gl_SIZE_MAX
   # Code from module snprintf:
@@ -352,6 +364,9 @@ AC_DEFUN([gl_INIT],
   gl_UNISTD_H
   # Code from module unistd-safer:
   gl_UNISTD_SAFER
+  # Code from module unsetenv:
+  gl_FUNC_UNSETENV
+  gl_STDLIB_MODULE_INDICATOR([unsetenv])
   # Code from module vasnprintf:
   gl_FUNC_VASNPRINTF
   # Code from module vasprintf:
@@ -586,6 +601,9 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/localcharset.h
   lib/locale.in.h
   lib/malloc.c
+  lib/malloca.c
+  lib/malloca.h
+  lib/malloca.valgrind
   lib/math.in.h
   lib/mbrtowc.c
   lib/mbsinit.c
@@ -617,6 +635,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/safe-read.h
   lib/safe-write.c
   lib/safe-write.h
+  lib/setenv.c
   lib/sha1.c
   lib/sha1.h
   lib/size_max.h
@@ -648,6 +667,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/unistd--.h
   lib/unistd-safer.h
   lib/unistd.in.h
+  lib/unsetenv.c
   lib/vasnprintf.c
   lib/vasnprintf.h
   lib/vasprintf.c
@@ -677,6 +697,8 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/dos.m4
   m4/double-slash-root.m4
   m4/dup2.m4
+  m4/eealloc.m4
+  m4/environ.m4
   m4/errno_h.m4
   m4/error.m4
   m4/extensions.m4
@@ -724,6 +746,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/longlong.m4
   m4/ls-mntd-fs.m4
   m4/malloc.m4
+  m4/malloca.m4
   m4/math_h.m4
   m4/mbrtowc.m4
   m4/mbsinit.m4
@@ -748,6 +771,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/safe-read.m4
   m4/safe-write.m4
   m4/servent.m4
+  m4/setenv.m4
   m4/sha1.m4
   m4/size_max.m4
   m4/snprintf.m4
diff --git a/gl/m4/malloca.m4 b/gl/m4/malloca.m4
new file mode 100644
index 0000000..e07c6d9
--- /dev/null
+++ b/gl/m4/malloca.m4
@@ -0,0 +1,15 @@
+# malloca.m4 serial 1
+dnl Copyright (C) 2003-2004, 2006-2007, 2009-2010 Free Software Foundation,
+dnl 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_MALLOCA],
+[
+  dnl Use the autoconf tests for alloca(), but not the AC_SUBSTed variables
+  dnl @ALLOCA@ and @LTALLOCA@.
+  dnl gl_FUNC_ALLOCA   dnl Already brought in by the module dependencies.
+  AC_REQUIRE([gl_EEMALLOC])
+  AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
+])
diff --git a/gl/m4/setenv.m4 b/gl/m4/setenv.m4
new file mode 100644
index 0000000..58f6d13
--- /dev/null
+++ b/gl/m4/setenv.m4
@@ -0,0 +1,111 @@
+# setenv.m4 serial 16
+dnl Copyright (C) 2001-2004, 2006-2010 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])
+  if test $HAVE_SETENV$REPLACE_SETENV != 10; then
+    AC_LIBOBJ([setenv])
+  fi
+])
+
+# Like gl_FUNC_SETENV, except prepare for separate compilation (no AC_LIBOBJ).
+AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([setenv])
+  if test $ac_cv_func_setenv = no; then
+    HAVE_SETENV=0
+  else
+    AC_CACHE_CHECK([whether setenv validates arguments],
+      [gl_cv_func_setenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+       #include <errno.h>
+       #include <string.h>
+      ]], [[
+       if (setenv ("", "", 0) != -1) return 1;
+       if (errno != EINVAL) return 2;
+       if (setenv ("a", "=", 1) != 0) return 3;
+       if (strcmp (getenv ("a"), "=") != 0) return 4;
+      ]])],
+      [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no],
+      [gl_cv_func_setenv_works="guessing no"])])
+    if test "$gl_cv_func_setenv_works" != yes; then
+      REPLACE_SETENV=1
+      AC_LIBOBJ([setenv])
+    fi
+  fi
+  gl_PREREQ_SETENV
+])
+
+AC_DEFUN([gl_FUNC_UNSETENV],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_CHECK_FUNCS([unsetenv])
+  if test $ac_cv_func_unsetenv = no; then
+    HAVE_UNSETENV=0
+    AC_LIBOBJ([unsetenv])
+    gl_PREREQ_UNSETENV
+  else
+    dnl Some BSDs return void, failing to do error checking.
+    AC_CACHE_CHECK([for unsetenv() return type], [gt_cv_func_unsetenv_ret],
+      [AC_TRY_COMPILE([#include <stdlib.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+#if defined(__STDC__) || defined(__cplusplus)
+int unsetenv (const char *name);
+#else
+int unsetenv();
+#endif
+], , gt_cv_func_unsetenv_ret='int', gt_cv_func_unsetenv_ret='void')])
+    if test $gt_cv_func_unsetenv_ret = 'void'; then
+      AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void
+       instead of int.])
+      REPLACE_UNSETENV=1
+      AC_LIBOBJ([unsetenv])
+    fi
+
+    dnl Solaris 10 unsetenv does not remove all copies of a name.
+    AC_CACHE_CHECK([whether unsetenv works on duplicates],
+      [gl_cv_func_unsetenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+      ]], [[
+       char entry[] = "b=2";
+       if (putenv ((char *) "a=1")) return 1;
+       if (putenv (entry)) return 2;
+       entry[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 3;
+      ]])],
+      [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
+      [gl_cv_func_unsetenv_works="guessing no"])])
+    if test "$gl_cv_func_unsetenv_works" != yes; then
+      REPLACE_UNSETENV=1
+      AC_LIBOBJ([unsetenv])
+    fi
+  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/gl/malloca.c b/gl/malloca.c
new file mode 100644
index 0000000..21bbc1f
--- /dev/null
+++ b/gl/malloca.c
@@ -0,0 +1,140 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003, 2006-2007, 2009-2010 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "malloca.h"
+
+/* Use the system functions, not the gnulib overrides in this file.  */
+#undef malloc
+
+/* The speed critical point in this file is freea() applied to an alloca()
+   result: it must be fast, to match the speed of alloca().  The speed of
+   mmalloca() and freea() in the other case are not critical, because they
+   are only invoked for big memory sizes.  */
+
+#if HAVE_ALLOCA
+
+/* Store the mmalloca() results in a hash table.  This is needed to reliably
+   distinguish a mmalloca() result and an alloca() result.
+
+   Although it is possible that the same pointer is returned by alloca() and
+   by mmalloca() at different times in the same application, it does not lead
+   to a bug in freea(), because:
+     - Before a pointer returned by alloca() can point into malloc()ed memory,
+       the function must return, and once this has happened the programmer must
+       not call freea() on it anyway.
+     - Before a pointer returned by mmalloca() can point into the stack, it
+       must be freed.  The only function that can free it is freea(), and
+       when freea() frees it, it also removes it from the hash table.  */
+
+#define MAGIC_NUMBER 0x1415fb4a
+#define MAGIC_SIZE sizeof (int)
+/* This is how the header info would look like without any alignment
+   considerations.  */
+struct preliminary_header { void *next; char room[MAGIC_SIZE]; };
+/* But the header's size must be a multiple of sa_alignment_max.  */
+#define HEADER_SIZE \
+  (((sizeof (struct preliminary_header) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max)
+struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; };
+/* Verify that HEADER_SIZE == sizeof (struct header).  */
+typedef int verify1[2 * (HEADER_SIZE == sizeof (struct header)) - 1];
+/* We make the hash table quite big, so that during lookups the probability
+   of empty hash buckets is quite high.  There is no need to make the hash
+   table resizable, because when the hash table gets filled so much that the
+   lookup becomes slow, it means that the application has memory leaks.  */
+#define HASH_TABLE_SIZE 257
+static void * mmalloca_results[HASH_TABLE_SIZE];
+
+#endif
+
+void *
+mmalloca (size_t n)
+{
+#if HAVE_ALLOCA
+  /* Allocate one more word, that serves as an indicator for malloc()ed
+     memory, so that freea() of an alloca() result is fast.  */
+  size_t nplus = n + HEADER_SIZE;
+
+  if (nplus >= n)
+    {
+      char *p = (char *) malloc (nplus);
+
+      if (p != NULL)
+        {
+          size_t slot;
+
+          p += HEADER_SIZE;
+
+          /* Put a magic number into the indicator word.  */
+          ((int *) p)[-1] = MAGIC_NUMBER;
+
+          /* Enter p into the hash table.  */
+          slot = (unsigned long) p % HASH_TABLE_SIZE;
+          ((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot];
+          mmalloca_results[slot] = p;
+
+          return p;
+        }
+    }
+  /* Out of memory.  */
+  return NULL;
+#else
+# if !MALLOC_0_IS_NONNULL
+  if (n == 0)
+    n = 1;
+# endif
+  return malloc (n);
+#endif
+}
+
+#if HAVE_ALLOCA
+void
+freea (void *p)
+{
+  /* mmalloca() may have returned NULL.  */
+  if (p != NULL)
+    {
+      /* Attempt to quickly distinguish the mmalloca() result - which has
+         a magic indicator word - and the alloca() result - which has an
+         uninitialized indicator word.  It is for this test that sa_increment
+         additional bytes are allocated in the alloca() case.  */
+      if (((int *) p)[-1] == MAGIC_NUMBER)
+        {
+          /* Looks like a mmalloca() result.  To see whether it really is one,
+             perform a lookup in the hash table.  */
+          size_t slot = (unsigned long) p % HASH_TABLE_SIZE;
+          void **chain = &mmalloca_results[slot];
+          for (; *chain != NULL;)
+            {
+              if (*chain == p)
+                {
+                  /* Found it.  Remove it from the hash table and free it.  */
+                  char *p_begin = (char *) p - HEADER_SIZE;
+                  *chain = ((struct header *) p_begin)->next;
+                  free (p_begin);
+                  return;
+                }
+              chain = &((struct header *) ((char *) *chain - HEADER_SIZE))->next;
+            }
+        }
+      /* At this point, we know it was not a mmalloca() result.  */
+    }
+}
+#endif
diff --git a/gl/malloca.h b/gl/malloca.h
new file mode 100644
index 0000000..0d5ded3
--- /dev/null
+++ b/gl/malloca.h
@@ -0,0 +1,134 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003-2007, 2009-2010 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _MALLOCA_H
+#define _MALLOCA_H
+
+#include <alloca.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* safe_alloca(N) is equivalent to alloca(N) when it is safe to call
+   alloca(N); otherwise it returns NULL.  It either returns N bytes of
+   memory allocated on the stack, that lasts until the function returns,
+   or NULL.
+   Use of safe_alloca should be avoided:
+     - inside arguments of function calls - undefined behaviour,
+     - in inline functions - the allocation may actually last until the
+       calling function returns.
+*/
+#if HAVE_ALLOCA
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.
+   This must be a macro, not an inline function.  */
+# define safe_alloca(N) ((N) < 4032 ? alloca (N) : NULL)
+#else
+# define safe_alloca(N) ((void) (N), NULL)
+#endif
+
+/* malloca(N) is a safe variant of alloca(N).  It allocates N bytes of
+   memory allocated on the stack, that must be freed using freea() before
+   the function returns.  Upon failure, it returns NULL.  */
+#if HAVE_ALLOCA
+# define malloca(N) \
+  ((N) < 4032 - sa_increment                                        \
+   ? (void *) ((char *) alloca ((N) + sa_increment) + sa_increment) \
+   : mmalloca (N))
+#else
+# define malloca(N) \
+  mmalloca (N)
+#endif
+extern void * mmalloca (size_t n);
+
+/* Free a block of memory allocated through malloca().  */
+#if HAVE_ALLOCA
+extern void freea (void *p);
+#else
+# define freea free
+#endif
+
+/* nmalloca(N,S) is an overflow-safe variant of malloca (N * S).
+   It allocates an array of N objects, each with S bytes of memory,
+   on the stack.  S must be positive and N must be nonnegative.
+   The array must be freed using freea() before the function returns.  */
+#if 1
+/* Cf. the definition of xalloc_oversized.  */
+# define nmalloca(n, s) \
+    ((n) > (size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) \
+     ? NULL \
+     : malloca ((n) * (s)))
+#else
+extern void * nmalloca (size_t n, size_t s);
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+/* ------------------- Auxiliary, non-public definitions ------------------- */
+
+/* Determine the alignment of a type at compile time.  */
+#if defined __GNUC__
+# define sa_alignof __alignof__
+#elif defined __cplusplus
+  template <class type> struct sa_alignof_helper { char __slot1; type __slot2; };
+# define sa_alignof(type) offsetof (sa_alignof_helper<type>, __slot2)
+#elif defined __hpux
+  /* Work around a HP-UX 10.20 cc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#elif defined _AIX
+  /* Work around an AIX 3.2.5 xlc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#else
+# define sa_alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
+#endif
+
+enum
+{
+/* The desired alignment of memory allocations is the maximum alignment
+   among all elementary types.  */
+  sa_alignment_long = sa_alignof (long),
+  sa_alignment_double = sa_alignof (double),
+#if HAVE_LONG_LONG_INT
+  sa_alignment_longlong = sa_alignof (long long),
+#endif
+  sa_alignment_longdouble = sa_alignof (long double),
+  sa_alignment_max = ((sa_alignment_long - 1) | (sa_alignment_double - 1)
+#if HAVE_LONG_LONG_INT
+                      | (sa_alignment_longlong - 1)
+#endif
+                      | (sa_alignment_longdouble - 1)
+                     ) + 1,
+/* The increment that guarantees room for a magic word must be >= sizeof (int)
+   and a multiple of sa_alignment_max.  */
+  sa_increment = ((sizeof (int) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max
+};
+
+#endif /* _MALLOCA_H */
diff --git a/gl/malloca.valgrind b/gl/malloca.valgrind
new file mode 100644
index 0000000..52f0a50
--- /dev/null
+++ b/gl/malloca.valgrind
@@ -0,0 +1,7 @@
+# Suppress a valgrind message about use of uninitialized memory in freea().
+# This use is OK because it provides only a speedup.
+{
+    freea
+    Memcheck:Cond
+    fun:freea
+}
diff --git a/gl/setenv.c b/gl/setenv.c
new file mode 100644
index 0000000..ba760d6
--- /dev/null
+++ b/gl/setenv.c
@@ -0,0 +1,390 @@
+/* Copyright (C) 1992, 1995-2003, 2005-2010 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
+# include <config.h>
+#endif
+
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+#define _GL_ARG_NONNULL(params)
+
+#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
+#else
+/* Use the system functions, not the gnulib overrides in this file.  */
+# undef malloc
+# undef realloc
+#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
+# 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/gl/unsetenv.c b/gl/unsetenv.c
new file mode 100644
index 0000000..65a19cc
--- /dev/null
+++ b/gl/unsetenv.c
@@ -0,0 +1,120 @@
+/* Copyright (C) 1992, 1995-2002, 2005-2010 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/>.  */
+
+#include <config.h>
+
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+#define _GL_ARG_NONNULL(params)
+
+/* 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
+
+/* 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 */