xref: /netbsd-src/external/gpl2/diffutils/dist/m4/c-bs-a.m4 (revision 75f6d617e282811cb173c2ccfbf5df0dd71f7045)
1*75f6d617Schristos#serial 4
2*75f6d617Schristos
3*75f6d617Schristosdnl From Paul Eggert.
4*75f6d617Schristos
5*75f6d617SchristosAC_DEFUN([AC_C_BACKSLASH_A],
6*75f6d617Schristos[
7*75f6d617Schristos  AC_CACHE_CHECK([whether backslash-a works in strings], ac_cv_c_backslash_a,
8*75f6d617Schristos   [AC_TRY_COMPILE([],
9*75f6d617Schristos     [
10*75f6d617Schristos#if '\a' == 'a'
11*75f6d617Schristos      syntax error;
12*75f6d617Schristos#endif
13*75f6d617Schristos      char buf['\a' == 'a' ? -1 : 1];
14*75f6d617Schristos      buf[0] = '\a';
15*75f6d617Schristos      return buf[0] != "\a"[0];
16*75f6d617Schristos     ],
17*75f6d617Schristos     ac_cv_c_backslash_a=yes,
18*75f6d617Schristos     ac_cv_c_backslash_a=no)])
19*75f6d617Schristos  if test $ac_cv_c_backslash_a = yes; then
20*75f6d617Schristos    AC_DEFINE(HAVE_C_BACKSLASH_A, 1,
21*75f6d617Schristos      [Define if backslash-a works in C strings.])
22*75f6d617Schristos  fi
23*75f6d617Schristos])
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