1# btowc.m4 serial 12
2dnl Copyright (C) 2008-2021 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_BTOWC],
8[
9  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
10
11  dnl Check whether <wchar.h> is usable at all, first. Otherwise the test
12  dnl program below may lead to an endless loop. See
13  dnl <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>.
14  AC_REQUIRE([gl_WCHAR_H_INLINE_OK])
15
16  AC_CHECK_FUNCS_ONCE([btowc])
17  if test $ac_cv_func_btowc = no; then
18    HAVE_BTOWC=0
19  else
20
21    AC_REQUIRE([AC_PROG_CC])
22    AC_REQUIRE([gt_LOCALE_FR])
23    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
24
25    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.
26    AC_CACHE_CHECK([whether btowc(0) is correct],
27      [gl_cv_func_btowc_nul],
28      [
29        AC_RUN_IFELSE(
30          [AC_LANG_SOURCE([[
31#include <wchar.h>
32int main ()
33{
34  if (btowc ('\0') != 0)
35    return 1;
36  return 0;
37}]])],
38          [gl_cv_func_btowc_nul=yes],
39          [gl_cv_func_btowc_nul=no],
40          [
41changequote(,)dnl
42           case "$host_os" in
43                      # Guess no on Cygwin.
44             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;
45                      # Guess yes on native Windows.
46             mingw*)  gl_cv_func_btowc_nul="guessing yes" ;;
47                      # Guess yes otherwise.
48             *)       gl_cv_func_btowc_nul="guessing yes" ;;
49           esac
50changequote([,])dnl
51          ])
52      ])
53
54    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
55    AC_CACHE_CHECK([whether btowc(EOF) is correct],
56      [gl_cv_func_btowc_eof],
57      [
58        dnl Initial guess, used when cross-compiling or when no suitable locale
59        dnl is present.
60changequote(,)dnl
61        case "$host_os" in
62                  # Guess no on IRIX.
63          irix*)  gl_cv_func_btowc_eof="guessing no" ;;
64                  # Guess yes on native Windows.
65          mingw*) gl_cv_func_btowc_eof="guessing yes" ;;
66                  # Guess yes otherwise.
67          *)      gl_cv_func_btowc_eof="guessing yes" ;;
68        esac
69changequote([,])dnl
70        if test $LOCALE_FR != none; then
71          AC_RUN_IFELSE(
72            [AC_LANG_SOURCE([[
73#include <locale.h>
74#include <stdio.h>
75#include <wchar.h>
76int main ()
77{
78  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
79    {
80      if (btowc (EOF) != WEOF)
81        return 1;
82    }
83  return 0;
84}]])],
85            [gl_cv_func_btowc_eof=yes],
86            [gl_cv_func_btowc_eof=no],
87            [:])
88        fi
89      ])
90
91    case "$gl_cv_func_btowc_nul" in
92      *yes) ;;
93      *) REPLACE_BTOWC=1 ;;
94    esac
95    case "$gl_cv_func_btowc_eof" in
96      *yes) ;;
97      *) REPLACE_BTOWC=1 ;;
98    esac
99  fi
100])
101
102# Prerequisites of lib/btowc.c.
103AC_DEFUN([gl_PREREQ_BTOWC], [
104  :
105])
106