xref: /netbsd-src/external/gpl3/gdb.old/dist/gnulib/import/m4/btowc.m4 (revision 2dd295436a0082eb4f8d294f4aa73c223413d0f2)
1# btowc.m4 serial 11
2dnl Copyright (C) 2008-2020 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_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 $ac_cv_func_btowc = no; then
18    HAVE_BTOWC=0
19  else
20
21    AC_REQUIRE([AC_PROG_CC])
22    AC_REQUIRE([gt_LOCALE_FR])
23    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
24
25    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.
26    AC_CACHE_CHECK([whether btowc(0) is correct],
27      [gl_cv_func_btowc_nul],
28      [
29        AC_RUN_IFELSE(
30          [AC_LANG_SOURCE([[
31#include <string.h>
32/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
33   <wchar.h>.
34   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
35   included before <wchar.h>.  */
36#include <stddef.h>
37#include <stdio.h>
38#include <time.h>
39#include <wchar.h>
40int main ()
41{
42  if (btowc ('\0') != 0)
43    return 1;
44  return 0;
45}]])],
46          [gl_cv_func_btowc_nul=yes],
47          [gl_cv_func_btowc_nul=no],
48          [
49changequote(,)dnl
50           case "$host_os" in
51                      # Guess no on Cygwin.
52             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;
53                      # Guess yes on native Windows.
54             mingw*)  gl_cv_func_btowc_nul="guessing yes" ;;
55                      # Guess yes otherwise.
56             *)       gl_cv_func_btowc_nul="guessing yes" ;;
57           esac
58changequote([,])dnl
59          ])
60      ])
61
62    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
63    AC_CACHE_CHECK([whether btowc(EOF) is correct],
64      [gl_cv_func_btowc_eof],
65      [
66        dnl Initial guess, used when cross-compiling or when no suitable locale
67        dnl is present.
68changequote(,)dnl
69        case "$host_os" in
70                  # Guess no on IRIX.
71          irix*)  gl_cv_func_btowc_eof="guessing no" ;;
72                  # Guess yes on native Windows.
73          mingw*) gl_cv_func_btowc_eof="guessing yes" ;;
74                  # Guess yes otherwise.
75          *)      gl_cv_func_btowc_eof="guessing yes" ;;
76        esac
77changequote([,])dnl
78        if test $LOCALE_FR != none; then
79          AC_RUN_IFELSE(
80            [AC_LANG_SOURCE([[
81#include <locale.h>
82#include <string.h>
83/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
84   <wchar.h>.
85   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
86   included before <wchar.h>.  */
87#include <stddef.h>
88#include <stdio.h>
89#include <time.h>
90#include <wchar.h>
91int main ()
92{
93  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
94    {
95      if (btowc (EOF) != WEOF)
96        return 1;
97    }
98  return 0;
99}]])],
100            [gl_cv_func_btowc_eof=yes],
101            [gl_cv_func_btowc_eof=no],
102            [:])
103        fi
104      ])
105
106    case "$gl_cv_func_btowc_nul" in
107      *yes) ;;
108      *) REPLACE_BTOWC=1 ;;
109    esac
110    case "$gl_cv_func_btowc_eof" in
111      *yes) ;;
112      *) REPLACE_BTOWC=1 ;;
113    esac
114  fi
115])
116
117# Prerequisites of lib/btowc.c.
118AC_DEFUN([gl_PREREQ_BTOWC], [
119  :
120])
121