summaryrefslogtreecommitdiffstats
path: root/gl/m4/btowc.m4
blob: 1cd100a2d7e8631d1e5c2f59676cf884d65713c0 (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
150
151
152
153
154
155
156
157
158
159
160
# btowc.m4 serial 13
dnl Copyright (C) 2008-2023 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_BTOWC],
[
  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])

  dnl Check whether <wchar.h> is usable at all, first. Otherwise the test
  dnl program below may lead to an endless loop. See
  dnl <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>.
  AC_REQUIRE([gl_WCHAR_H_INLINE_OK])

  AC_CHECK_FUNCS_ONCE([btowc])
  if test $ac_cv_func_btowc = no; then
    HAVE_BTOWC=0
  else

    AC_REQUIRE([AC_PROG_CC])
    AC_REQUIRE([gt_LOCALE_FR])
    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.
    AC_CACHE_CHECK([whether btowc(0) is correct],
      [gl_cv_func_btowc_nul],
      [
        AC_RUN_IFELSE(
          [AC_LANG_SOURCE([[
#include <wchar.h>
int main ()
{
  if (btowc ('\0') != 0)
    return 1;
  return 0;
}]])],
          [gl_cv_func_btowc_nul=yes],
          [gl_cv_func_btowc_nul=no],
          [
changequote(,)dnl
           case "$host_os" in
                      # Guess no on Cygwin.
             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;
                      # Guess yes on native Windows.
             mingw*)  gl_cv_func_btowc_nul="guessing yes" ;;
                      # Guess yes otherwise.
             *)       gl_cv_func_btowc_nul="guessing yes" ;;
           esac
changequote([,])dnl
          ])
      ])

    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
    AC_CACHE_CHECK([whether btowc(EOF) is correct],
      [gl_cv_func_btowc_eof],
      [
        dnl Initial guess, used when cross-compiling or when no suitable locale
        dnl is present.
changequote(,)dnl
        case "$host_os" in
                  # Guess no on IRIX.
          irix*)  gl_cv_func_btowc_eof="guessing no" ;;
                  # Guess yes on native Windows.
          mingw*) gl_cv_func_btowc_eof="guessing yes" ;;
                  # Guess yes otherwise.
          *)      gl_cv_func_btowc_eof="guessing yes" ;;
        esac
changequote([,])dnl
        if test $LOCALE_FR != none; then
          AC_RUN_IFELSE(
            [AC_LANG_SOURCE([[
#include <locale.h>
#include <stdio.h>
#include <wchar.h>
int main ()
{
  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
    {
      if (btowc (EOF) != WEOF)
        return 1;
    }
  return 0;
}]])],
            [gl_cv_func_btowc_eof=yes],
            [gl_cv_func_btowc_eof=no],
            [:])
        fi
      ])

    dnl On mingw, in the C locale, btowc is inconsistent with mbrtowc:
    dnl mbrtowc avoids calling MultiByteToWideChar when MB_CUR_MAX is 1 and
    dnl ___lc_codepage_func() is 0, but btowc is lacking this special case.
    AC_CHECK_FUNCS_ONCE([mbrtowc])
    AC_CACHE_CHECK([whether btowc is consistent with mbrtowc in the C locale],
      [gl_cv_func_btowc_consistent],
      [
        AC_RUN_IFELSE(
          [AC_LANG_SOURCE([[
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
int main ()
{
#if HAVE_MBRTOWC
  wint_t wc1 = btowc (0x80);
  wchar_t wc2 = (wchar_t) 0xbadface;
  char buf[1] = { 0x80 };
  mbstate_t state;
  memset (&state, 0, sizeof (mbstate_t));
  if (mbrtowc (&wc2, buf, 1, &state) != 1 || wc1 != wc2)
    return 1;
#endif
  return 0;
}]])],
          [gl_cv_func_btowc_consistent=yes],
          [gl_cv_func_btowc_consistent=no],
          [case "$host_os" in
                     # Guess no on mingw.
             mingw*) AC_EGREP_CPP([Problem], [
#ifdef __MINGW32__
 Problem
#endif
                       ],
                       [gl_cv_func_btowc_consistent="guessing no"],
                       [gl_cv_func_btowc_consistent="guessing yes"])
                     ;;
                     # Guess yes otherwise.
             *)      gl_cv_func_btowc_consistent="guessing yes" ;;
           esac
          ])
      ])

    case "$gl_cv_func_btowc_nul" in
      *yes) ;;
      *) REPLACE_BTOWC=1 ;;
    esac
    case "$gl_cv_func_btowc_eof" in
      *yes) ;;
      *) REPLACE_BTOWC=1 ;;
    esac
    case "$gl_cv_func_btowc_consistent" in
      *yes) ;;
      *) REPLACE_BTOWC=1 ;;
    esac
    if test $REPLACE_BTOWC = 0; then
      gl_MBRTOWC_C_LOCALE
      case "$gl_cv_func_mbrtowc_C_locale_sans_EILSEQ" in
        *yes) ;;
        *) REPLACE_BTOWC=1 ;;
      esac
    fi
  fi
])

# Prerequisites of lib/btowc.c.
AC_DEFUN([gl_PREREQ_BTOWC], [
  :
  AC_CHECK_FUNCS_ONCE([mbrtowc])
])