1 # setenv.m4 serial 26 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 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 11 if test $ac_cv_func_setenv = no; then 12 HAVE_SETENV=0 13 else 14 AC_CACHE_CHECK([whether setenv validates arguments], 15 [gl_cv_func_setenv_works], 16 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ 17 #include <stdlib.h> 18 #include <errno.h> 19 #include <string.h> 20 ]], [[ 21 int result = 0; 22 { 23 if (setenv ("", "", 0) != -1) 24 result |= 1; 25 else if (errno != EINVAL) 26 result |= 2; 27 } 28 { 29 if (setenv ("a", "=", 1) != 0) 30 result |= 4; 31 else if (strcmp (getenv ("a"), "=") != 0) 32 result |= 8; 33 } 34 return result; 35 ]])], 36 [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no], 37 [case "$host_os" in 38 # Guess yes on glibc systems. 39 *-gnu*) gl_cv_func_setenv_works="guessing yes" ;; 40 # If we don't know, assume the worst. 41 *) gl_cv_func_setenv_works="guessing no" ;; 42 esac 43 ])]) 44 case "$gl_cv_func_setenv_works" in 45 *yes) ;; 46 *) 47 REPLACE_SETENV=1 48 ;; 49 esac 50 fi 51 ]) 52 53 # Like gl_FUNC_SETENV, except prepare for separate compilation 54 # (no REPLACE_SETENV, no AC_LIBOBJ). 55 AC_DEFUN([gl_FUNC_SETENV_SEPARATE], 56 [ 57 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 58 AC_CHECK_DECLS_ONCE([setenv]) 59 if test $ac_cv_have_decl_setenv = no; then 60 HAVE_DECL_SETENV=0 61 fi 62 AC_CHECK_FUNCS_ONCE([setenv]) 63 gl_PREREQ_SETENV 64 ]) 65 66 AC_DEFUN([gl_FUNC_UNSETENV], 67 [ 68 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 69 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 70 AC_CHECK_DECLS_ONCE([unsetenv]) 71 if test $ac_cv_have_decl_unsetenv = no; then 72 HAVE_DECL_UNSETENV=0 73 fi 74 AC_CHECK_FUNCS([unsetenv]) 75 if test $ac_cv_func_unsetenv = no; then 76 HAVE_UNSETENV=0 77 else 78 HAVE_UNSETENV=1 79 dnl Some BSDs return void, failing to do error checking. 80 AC_CACHE_CHECK([for unsetenv() return type], [gt_cv_func_unsetenv_ret], 81 [AC_COMPILE_IFELSE( 82 [AC_LANG_PROGRAM( 83 [[ 84 #undef _BSD 85 #define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */ 86 #include <stdlib.h> 87 extern 88 #ifdef __cplusplus 89 "C" 90 #endif 91 int unsetenv (const char *name); 92 ]], 93 [[]])], 94 [gt_cv_func_unsetenv_ret='int'], 95 [gt_cv_func_unsetenv_ret='void'])]) 96 if test $gt_cv_func_unsetenv_ret = 'void'; then 97 AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void 98 instead of int.]) 99 REPLACE_UNSETENV=1 100 fi 101 102 dnl Solaris 10 unsetenv does not remove all copies of a name. 103 dnl Haiku alpha 2 unsetenv gets confused by assignment to environ. 104 dnl OpenBSD 4.7 unsetenv("") does not fail. 105 AC_CACHE_CHECK([whether unsetenv obeys POSIX], 106 [gl_cv_func_unsetenv_works], 107 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ 108 #include <stdlib.h> 109 #include <errno.h> 110 extern char **environ; 111 ]], [[ 112 char entry1[] = "a=1"; 113 char entry2[] = "b=2"; 114 char *env[] = { entry1, entry2, NULL }; 115 if (putenv ((char *) "a=1")) return 1; 116 if (putenv (entry2)) return 2; 117 entry2[0] = 'a'; 118 unsetenv ("a"); 119 if (getenv ("a")) return 3; 120 if (!unsetenv ("") || errno != EINVAL) return 4; 121 entry2[0] = 'b'; 122 environ = env; 123 if (!getenv ("a")) return 5; 124 entry2[0] = 'a'; 125 unsetenv ("a"); 126 if (getenv ("a")) return 6; 127 ]])], 128 [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no], 129 [case "$host_os" in 130 # Guess yes on glibc systems. 131 *-gnu*) gl_cv_func_unsetenv_works="guessing yes" ;; 132 # If we don't know, assume the worst. 133 *) gl_cv_func_unsetenv_works="guessing no" ;; 134 esac 135 ])]) 136 case "$gl_cv_func_unsetenv_works" in 137 *yes) ;; 138 *) 139 REPLACE_UNSETENV=1 140 ;; 141 esac 142 fi 143 ]) 144 145 # Prerequisites of lib/setenv.c. 146 AC_DEFUN([gl_PREREQ_SETENV], 147 [ 148 AC_REQUIRE([AC_FUNC_ALLOCA]) 149 AC_REQUIRE([gl_ENVIRON]) 150 AC_CHECK_HEADERS_ONCE([unistd.h]) 151 AC_CHECK_HEADERS([search.h]) 152 AC_CHECK_FUNCS([tsearch]) 153 ]) 154 155 # Prerequisites of lib/unsetenv.c. 156 AC_DEFUN([gl_PREREQ_UNSETENV], 157 [ 158 AC_REQUIRE([gl_ENVIRON]) 159 AC_CHECK_HEADERS_ONCE([unistd.h]) 160 ]) 161
