Import Gnulib's `setenv' module, for MinGW.

Reported by Eli Zaretskii <eliz@gnu.org>.

* m4/gnulib-cache.m4 (gl_MODULES): Add `setenv'.

lib/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 --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nproc open pipe2 putenv recv recvfrom rename send sendto setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nproc open pipe2 putenv recv recvfrom rename send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
 
 AUTOMAKE_OPTIONS = 1.5 gnits subdir-objects
 
@@ -1343,6 +1343,15 @@ EXTRA_libgnu_la_SOURCES += sendto.c
 
 ## end   gnulib module sendto
 
+## begin gnulib module setenv
+
+
+EXTRA_DIST += setenv.c
+
+EXTRA_libgnu_la_SOURCES += setenv.c
+
+## end   gnulib module setenv
+
 ## begin gnulib module setsockopt
 
 

lib/setenv.c

@@ -0,0 +1,390 @@
+/* Copyright (C) 1992, 1995-2003, 2005-2012 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 Lesser 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#if !_LIBC
+# define _GL_USE_STDLIB_ALLOC 1
+# 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
+#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 */

m4/gnulib-cache.m4

@@ -27,7 +27,7 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nproc open pipe2 putenv recv recvfrom rename send sendto setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
+#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nproc open pipe2 putenv recv recvfrom rename send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([gnulib-local])
@@ -89,6 +89,7 @@ gl_MODULES([
   rename
   send
   sendto
+  setenv
   setsockopt
   shutdown
   socket

m4/gnulib-comp.m4

@@ -149,6 +149,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module send:
   # Code from module sendto:
   # Code from module servent:
+  # Code from module setenv:
   # Code from module setsockopt:
   # Code from module shutdown:
   # Code from module signal-h:
@@ -523,6 +524,11 @@ if test "$ac_cv_header_winsock2_h" = yes; then
 fi
 gl_SYS_SOCKET_MODULE_INDICATOR([sendto])
 gl_SERVENT
+gl_FUNC_SETENV
+if test $HAVE_SETENV = 0 || test $REPLACE_SETENV = 1; then
+  AC_LIBOBJ([setenv])
+fi
+gl_STDLIB_MODULE_INDICATOR([setenv])
 AC_REQUIRE([gl_HEADER_SYS_SOCKET])
 if test "$ac_cv_header_winsock2_h" = yes; then
   AC_LIBOBJ([setsockopt])
@@ -886,6 +892,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/same-inode.h
   lib/send.c
   lib/sendto.c
+  lib/setenv.c
   lib/setsockopt.c
   lib/shutdown.c
   lib/signal.in.h
@@ -1027,6 +1034,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/safe-read.m4
   m4/safe-write.m4
   m4/servent.m4
+  m4/setenv.m4
   m4/signal_h.m4
   m4/size_max.m4
   m4/snprintf.m4

m4/setenv.m4

@@ -0,0 +1,140 @@
+# setenv.m4 serial 25
+dnl Copyright (C) 2001-2004, 2006-2012 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 $ac_cv_func_setenv = no; then
+    HAVE_SETENV=0
+  else
+    AC_CACHE_CHECK([whether setenv validates arguments],
+      [gl_cv_func_setenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+       #include <errno.h>
+       #include <string.h>
+      ]], [[
+       int result = 0;
+       {
+         if (setenv ("", "", 0) != -1)
+           result |= 1;
+         else if (errno != EINVAL)
+           result |= 2;
+       }
+       {
+         if (setenv ("a", "=", 1) != 0)
+           result |= 4;
+         else if (strcmp (getenv ("a"), "=") != 0)
+           result |= 8;
+       }
+       return result;
+      ]])],
+      [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no],
+      [gl_cv_func_setenv_works="guessing no"])])
+    if test "$gl_cv_func_setenv_works" != yes; then
+      REPLACE_SETENV=1
+    fi
+  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_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 $gt_cv_func_unsetenv_ret = 'void'; then
+      AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void
+       instead of int.])
+      REPLACE_UNSETENV=1
+    fi
+
+    dnl Solaris 10 unsetenv does not remove all copies of a name.
+    dnl Haiku alpha 2 unsetenv gets confused by assignment to environ.
+    dnl OpenBSD 4.7 unsetenv("") does not fail.
+    AC_CACHE_CHECK([whether unsetenv obeys POSIX],
+      [gl_cv_func_unsetenv_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       #include <stdlib.h>
+       #include <errno.h>
+       extern char **environ;
+      ]], [[
+       char entry1[] = "a=1";
+       char entry2[] = "b=2";
+       char *env[] = { entry1, entry2, NULL };
+       if (putenv ((char *) "a=1")) return 1;
+       if (putenv (entry2)) return 2;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 3;
+       if (!unsetenv ("") || errno != EINVAL) return 4;
+       entry2[0] = 'b';
+       environ = env;
+       if (!getenv ("a")) return 5;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 6;
+      ]])],
+      [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
+      [gl_cv_func_unsetenv_works="guessing no"])])
+    if test "$gl_cv_func_unsetenv_works" != yes; then
+      REPLACE_UNSETENV=1
+    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])
+])