m4/setenv.m4

   1 # setenv.m4 serial 25
   2 dnl Copyright (C) 2001-2004, 2006-2012 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 AC_DEFUN([gl_FUNC_SETENV],
   8 [
   9   AC_REQUIRE([gl_FUNC_SETENV_SEPARATE])
  10   if test $ac_cv_func_setenv = no; then
  11     HAVE_SETENV=0
  12   else
  13     AC_CACHE_CHECK([whether setenv validates arguments],
  14       [gl_cv_func_setenv_works],
  15       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
  16        #include <stdlib.h>
  17        #include <errno.h>
  18        #include <string.h>
  19       ]], [[
  20        int result = 0;
  21        {
  22          if (setenv ("", "", 0) != -1)
  23            result |= 1;
  24          else if (errno != EINVAL)
  25            result |= 2;
  26        }
  27        {
  28          if (setenv ("a", "=", 1) != 0)
  29            result |= 4;
  30          else if (strcmp (getenv ("a"), "=") != 0)
  31            result |= 8;
  32        }
  33        return result;
  34       ]])],
  35       [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no],
  36       [gl_cv_func_setenv_works="guessing no"])])
  37     if test "$gl_cv_func_setenv_works" != yes; then
  38       REPLACE_SETENV=1
  39     fi
  40   fi
  41 ])
  42
  43 # Like gl_FUNC_SETENV, except prepare for separate compilation
  44 # (no REPLACE_SETENV, no AC_LIBOBJ).
  45 AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
  46 [
  47   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  48   AC_CHECK_DECLS_ONCE([setenv])
  49   if test $ac_cv_have_decl_setenv = no; then
  50     HAVE_DECL_SETENV=0
  51   fi
  52   AC_CHECK_FUNCS_ONCE([setenv])
  53   gl_PREREQ_SETENV
  54 ])
  55
  56 AC_DEFUN([gl_FUNC_UNSETENV],
  57 [
  58   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  59   AC_CHECK_DECLS_ONCE([unsetenv])
  60   if test $ac_cv_have_decl_unsetenv = no; then
  61     HAVE_DECL_UNSETENV=0
  62   fi
  63   AC_CHECK_FUNCS([unsetenv])
  64   if test $ac_cv_func_unsetenv = no; then
  65     HAVE_UNSETENV=0
  66   else
  67     HAVE_UNSETENV=1
  68     dnl Some BSDs return void, failing to do error checking.
  69     AC_CACHE_CHECK([for unsetenv() return type], [gt_cv_func_unsetenv_ret],
  70       [AC_COMPILE_IFELSE(
  71          [AC_LANG_PROGRAM(
  72             [[
  73 #undef _BSD
  74 #define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */
  75 #include <stdlib.h>
  76 extern
  77 #ifdef __cplusplus
  78 "C"
  79 #endif
  80 int unsetenv (const char *name);
  81             ]],
  82             [[]])],
  83          [gt_cv_func_unsetenv_ret='int'],
  84          [gt_cv_func_unsetenv_ret='void'])])
  85     if test $gt_cv_func_unsetenv_ret = 'void'; then
  86       AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void
  87        instead of int.])
  88       REPLACE_UNSETENV=1
  89     fi
  90
  91     dnl Solaris 10 unsetenv does not remove all copies of a name.
  92     dnl Haiku alpha 2 unsetenv gets confused by assignment to environ.
  93     dnl OpenBSD 4.7 unsetenv("") does not fail.
  94     AC_CACHE_CHECK([whether unsetenv obeys POSIX],
  95       [gl_cv_func_unsetenv_works],
  96       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
  97        #include <stdlib.h>
  98        #include <errno.h>
  99        extern char **environ;
 100       ]], [[
 101        char entry1[] = "a=1";
 102        char entry2[] = "b=2";
 103        char *env[] = { entry1, entry2, NULL };
 104        if (putenv ((char *) "a=1")) return 1;
 105        if (putenv (entry2)) return 2;
 106        entry2[0] = 'a';
 107        unsetenv ("a");
 108        if (getenv ("a")) return 3;
 109        if (!unsetenv ("") || errno != EINVAL) return 4;
 110        entry2[0] = 'b';
 111        environ = env;
 112        if (!getenv ("a")) return 5;
 113        entry2[0] = 'a';
 114        unsetenv ("a");
 115        if (getenv ("a")) return 6;
 116       ]])],
 117       [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
 118       [gl_cv_func_unsetenv_works="guessing no"])])
 119     if test "$gl_cv_func_unsetenv_works" != yes; then
 120       REPLACE_UNSETENV=1
 121     fi
 122   fi
 123 ])
 124
 125 # Prerequisites of lib/setenv.c.
 126 AC_DEFUN([gl_PREREQ_SETENV],
 127 [
 128   AC_REQUIRE([AC_FUNC_ALLOCA])
 129   AC_REQUIRE([gl_ENVIRON])
 130   AC_CHECK_HEADERS_ONCE([unistd.h])
 131   AC_CHECK_HEADERS([search.h])
 132   AC_CHECK_FUNCS([tsearch])
 133 ])
 134
 135 # Prerequisites of lib/unsetenv.c.
 136 AC_DEFUN([gl_PREREQ_UNSETENV],
 137 [
 138   AC_REQUIRE([gl_ENVIRON])
 139   AC_CHECK_HEADERS_ONCE([unistd.h])
 140 ])