summaryrefslogtreecommitdiff
path: root/gnulib/m4/setenv.m4
blob: bc215a6d4dd72e8b44442186ef4285962933ff4a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
# setenv.m4 serial 25
dnl Copyright (C) 2001-2004, 2006-2011 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])
])