m4/mbstate_t.m4

   1 # serial 8
   2
   3 # From Paul Eggert.
   4
   5 # BeOS 5 has <wchar.h> but does not define mbstate_t,
   6 # so you can't declare an object of that type.
   7 # Check for this incompatibility with Standard C.
   8
   9 # Include stdlib.h first, because otherwise this test would fail on Linux
  10 # (at least glibc-2.1.3) because the "_XOPEN_SOURCE 500" definition elicits
  11 # a syntax error in wchar.h due to the use of undefined __int32_t.
  12
  13 AC_DEFUN(AC_MBSTATE_T,
  14   [
  15    AC_CHECK_HEADERS(stdlib.h)
  16
  17    AC_CACHE_CHECK([for mbstate_t], ac_cv_type_mbstate_t,
  18     [AC_TRY_COMPILE([
  19 #if HAVE_STDLIB_H
  20 # include <stdlib.h>
  21 #endif
  22 #include <wchar.h>],
  23       [mbstate_t x; return sizeof x;],
  24       ac_cv_type_mbstate_t=yes,
  25       ac_cv_type_mbstate_t=no)])
  26    if test $ac_cv_type_mbstate_t = no; then
  27      AC_DEFINE(mbstate_t, int,
  28                [Define to a type if <wchar.h> does not define.])
  29    fi])