1 files changed, 24 insertions, 0 deletions
diff --git a/aclocal.m4 b/aclocal.m4
index ee00375..8f5267c 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -552,6 +552,30 @@ AC_DEFUN(AC_ISC_POSIX,
   ]
 )
 
+#serial 3
+
+dnl From Paul Eggert.
+
+AC_DEFUN(AC_C_BACKSLASH_A,
+[
+  AC_CACHE_CHECK([whether backslash-a works in strings], ac_cv_c_backslash_a,
+   [AC_TRY_COMPILE([],
+     [
+#if '\a' == 'a'
+      syntax error;
+#endif
+      char buf['\a' == 'a' ? -1 : 1];
+      buf[0] = '\a';
+      return buf[0] != "\a"[0];
+     ],
+     ac_cv_c_backslash_a=yes,
+     ac_cv_c_backslash_a=no)])
+  if test $ac_cv_c_backslash_a = yes; then
+    AC_DEFINE(HAVE_C_BACKSLASH_A, 1,
+      [Define if backslash-a works in C strings.])
+  fi
+])
+
 # From Ulrich Drepper.
 
 # serial 1