xref: /netbsd-src/external/gpl2/diffutils/dist/m4/c-bs-a.m4 (revision 75f6d617e282811cb173c2ccfbf5df0dd71f7045)
1#serial 4
2
3dnl From Paul Eggert.
4
5AC_DEFUN([AC_C_BACKSLASH_A],
6[
7  AC_CACHE_CHECK([whether backslash-a works in strings], ac_cv_c_backslash_a,
8   [AC_TRY_COMPILE([],
9     [
10#if '\a' == 'a'
11      syntax error;
12#endif
13      char buf['\a' == 'a' ? -1 : 1];
14      buf[0] = '\a';
15      return buf[0] != "\a"[0];
16     ],
17     ac_cv_c_backslash_a=yes,
18     ac_cv_c_backslash_a=no)])
19  if test $ac_cv_c_backslash_a = yes; then
20    AC_DEFINE(HAVE_C_BACKSLASH_A, 1,
21      [Define if backslash-a works in C strings.])
22  fi
23])
24