1# setenv.m4 serial 29 2dnl Copyright (C) 2001-2004, 2006-2020 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7AC_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* | gnu*) gl_cv_func_setenv_works="guessing yes" ;; 40 # Guess yes on musl systems. 41 *-musl*) gl_cv_func_setenv_works="guessing yes" ;; 42 # Guess yes on bsd systems. 43 *bsd*) gl_cv_func_setenv_works="guessing yes" ;; 44 # If we don't know, obey --enable-cross-guesses. 45 *) gl_cv_func_setenv_works="$gl_cross_guess_normal" ;; 46 esac 47 ])]) 48 case "$gl_cv_func_setenv_works" in 49 *yes) ;; 50 *) 51 REPLACE_SETENV=1 52 ;; 53 esac 54 fi 55]) 56 57# Like gl_FUNC_SETENV, except prepare for separate compilation 58# (no REPLACE_SETENV, no AC_LIBOBJ). 59AC_DEFUN([gl_FUNC_SETENV_SEPARATE], 60[ 61 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 62 AC_CHECK_DECLS_ONCE([setenv]) 63 if test $ac_cv_have_decl_setenv = no; then 64 HAVE_DECL_SETENV=0 65 fi 66 AC_CHECK_FUNCS_ONCE([setenv]) 67 gl_PREREQ_SETENV 68]) 69 70AC_DEFUN([gl_FUNC_UNSETENV], 71[ 72 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 73 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 74 AC_CHECK_DECLS_ONCE([unsetenv]) 75 if test $ac_cv_have_decl_unsetenv = no; then 76 HAVE_DECL_UNSETENV=0 77 fi 78 AC_CHECK_FUNCS([unsetenv]) 79 if test $ac_cv_func_unsetenv = no; then 80 HAVE_UNSETENV=0 81 else 82 HAVE_UNSETENV=1 83 dnl Some BSDs return void, failing to do error checking. 84 AC_CACHE_CHECK([for unsetenv() return type], [gt_cv_func_unsetenv_ret], 85 [AC_COMPILE_IFELSE( 86 [AC_LANG_PROGRAM( 87 [[ 88#undef _BSD 89#define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */ 90#include <stdlib.h> 91extern 92#ifdef __cplusplus 93"C" 94#endif 95int unsetenv (const char *name); 96 ]], 97 [[]])], 98 [gt_cv_func_unsetenv_ret='int'], 99 [gt_cv_func_unsetenv_ret='void'])]) 100 if test $gt_cv_func_unsetenv_ret = 'void'; then 101 AC_DEFINE([VOID_UNSETENV], [1], [Define to 1 if unsetenv returns void 102 instead of int.]) 103 REPLACE_UNSETENV=1 104 fi 105 106 dnl Solaris 10 unsetenv does not remove all copies of a name. 107 dnl Haiku alpha 2 unsetenv gets confused by assignment to environ. 108 dnl OpenBSD 4.7 unsetenv("") does not fail. 109 AC_CACHE_CHECK([whether unsetenv obeys POSIX], 110 [gl_cv_func_unsetenv_works], 111 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ 112 #include <stdlib.h> 113 #include <errno.h> 114 extern char **environ; 115 ]], [[ 116 char entry1[] = "a=1"; 117 char entry2[] = "b=2"; 118 char *env[] = { entry1, entry2, NULL }; 119 if (putenv ((char *) "a=1")) return 1; 120 if (putenv (entry2)) return 2; 121 entry2[0] = 'a'; 122 unsetenv ("a"); 123 if (getenv ("a")) return 3; 124 if (!unsetenv ("") || errno != EINVAL) return 4; 125 entry2[0] = 'b'; 126 environ = env; 127 if (!getenv ("a")) return 5; 128 entry2[0] = 'a'; 129 unsetenv ("a"); 130 if (getenv ("a")) return 6; 131 ]])], 132 [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no], 133 [case "$host_os" in 134 # Guess yes on glibc systems. 135 *-gnu*) gl_cv_func_unsetenv_works="guessing yes" ;; 136 # Guess yes on bsd systems. 137 *bsd*) gl_cv_func_unsetenv_works="guessing yes" ;; 138 # If we don't know, obey --enable-cross-guesses. 139 *) gl_cv_func_unsetenv_works="$gl_cross_guess_normal" ;; 140 esac 141 ])]) 142 case "$gl_cv_func_unsetenv_works" in 143 *yes) ;; 144 *) 145 REPLACE_UNSETENV=1 146 ;; 147 esac 148 fi 149]) 150 151# Prerequisites of lib/setenv.c. 152AC_DEFUN([gl_PREREQ_SETENV], 153[ 154 AC_REQUIRE([AC_FUNC_ALLOCA]) 155 AC_REQUIRE([gl_ENVIRON]) 156 AC_CHECK_HEADERS_ONCE([unistd.h]) 157 AC_CHECK_HEADERS([search.h]) 158 AC_CHECK_FUNCS([tsearch]) 159]) 160 161# Prerequisites of lib/unsetenv.c. 162AC_DEFUN([gl_PREREQ_UNSETENV], 163[ 164 AC_REQUIRE([gl_ENVIRON]) 165 AC_CHECK_HEADERS_ONCE([unistd.h]) 166]) 167