summaryrefslogtreecommitdiffstats
path: root/m4/fopen.m4
blob: 50767f8288ab2bc9cb523d2b111d1ca8919a6a0b (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
141
142
143
144
145
146
147
148
149
# fopen.m4 serial 13
dnl Copyright (C) 2007-2022 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_FOPEN],
[
  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
  AC_REQUIRE([AC_CANONICAL_HOST])
  case "$host_os" in
    mingw* | pw*)
      dnl Replace fopen, for handling of "/dev/null".
      REPLACE_FOPEN=1
      dnl fopen on mingw also has the trailing slash bug.
      gl_cv_func_fopen_slash="guessing no"
      ;;
    *)
      dnl fopen("foo/", "w") should not create a file when the file name has a
      dnl trailing slash.
      AC_CACHE_CHECK([whether fopen recognizes a trailing slash],
        [gl_cv_func_fopen_slash],
        [
          AC_RUN_IFELSE(
            [AC_LANG_SOURCE([[
#include <stddef.h>
#include <stdio.h>
int main ()
{
  FILE *fp = fopen ("conftest.sl/", "w");
  int result = (fp != NULL);
  if (fp != NULL)
    fclose (fp);
  return result;
}]])],
            [gl_cv_func_fopen_slash=yes],
            [gl_cv_func_fopen_slash=no],
            [
changequote(,)dnl
             case "$host_os" in
               aix* | hpux* | solaris2.[0-9] | solaris2.[0-9].*)
                 gl_cv_func_fopen_slash="guessing no" ;;
               *)
                 gl_cv_func_fopen_slash="guessing yes" ;;
             esac
changequote([,])dnl
            ])
          rm -f conftest.sl
        ])
      ;;
  esac
  case "$gl_cv_func_fopen_slash" in
    *no)
      AC_DEFINE([FOPEN_TRAILING_SLASH_BUG], [1],
        [Define to 1 if fopen() fails to recognize a trailing slash.])
      REPLACE_FOPEN=1
      ;;
  esac
])

AC_DEFUN([gl_FUNC_FOPEN_GNU],
[
  AC_REQUIRE([gl_FUNC_FOPEN])
  AC_CACHE_CHECK([whether fopen supports the mode character 'x'],
    [gl_cv_func_fopen_mode_x],
    [rm -f conftest.x
     AC_RUN_IFELSE(
       [AC_LANG_SOURCE([[
#include <stdio.h>
#include <errno.h>
int main ()
{
  FILE *fp;
  fp = fopen ("conftest.x", "w");
  fclose (fp);
  fp = fopen ("conftest.x", "wx");
  if (fp != NULL)
    /* 'x' ignored */
    return 1;
  else if (errno == EEXIST)
    return 0;
  else
    /* 'x' rejected */
    return 2;
}]])],
       [gl_cv_func_fopen_mode_x=yes],
       [gl_cv_func_fopen_mode_x=no],
       [case "$host_os" in
          # Guess yes on glibc and musl systems.
          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)
            gl_cv_func_fopen_mode_x="guessing yes" ;;
          # If we don't know, obey --enable-cross-guesses.
          *)
            gl_cv_func_fopen_mode_x="$gl_cross_guess_normal" ;;
        esac
       ])
     rm -f conftest.x
    ])
  AC_CACHE_CHECK([whether fopen supports the mode character 'e'],
    [gl_cv_func_fopen_mode_e],
    [echo foo > conftest.x
     AC_RUN_IFELSE(
       [AC_LANG_SOURCE([[
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
]GL_MDA_DEFINES[
int main ()
{
  FILE *fp = fopen ("conftest.x", "re");
  if (fp != NULL)
    {
      if (fcntl (fileno (fp), F_GETFD) & FD_CLOEXEC)
        return 0;
      else
        /* 'e' ignored */
        return 1;
    }
  else
    /* 'e' rejected */
    return 2;
}]])],
       [gl_cv_func_fopen_mode_e=yes],
       [gl_cv_func_fopen_mode_e=no],
       [case "$host_os" in
          # Guess yes on glibc and musl systems.
          linux*-gnu* | gnu* | kfreebsd*-gnu | *-musl*)
            gl_cv_func_fopen_mode_e="guessing yes" ;;
          # Guess no on native Windows.
          mingw*)
            gl_cv_func_fopen_mode_e="guessing no" ;;
          # If we don't know, obey --enable-cross-guesses.
          *)
            gl_cv_func_fopen_mode_e="$gl_cross_guess_normal" ;;
        esac
       ])
     rm -f conftest.x
    ])
  REPLACE_FOPEN_FOR_FOPEN_GNU="$REPLACE_FOPEN"
  case "$gl_cv_func_fopen_mode_x" in
    *no) REPLACE_FOPEN_FOR_FOPEN_GNU=1 ;;
  esac
  case "$gl_cv_func_fopen_mode_e" in
    *no) REPLACE_FOPEN_FOR_FOPEN_GNU=1 ;;
  esac
])

# Prerequisites of lib/fopen.c.
AC_DEFUN([gl_PREREQ_FOPEN], [:])