1 files changed, 35 insertions, 0 deletions
diff --git a/m4/vararrays.m4 b/m4/vararrays.m4
new file mode 100644
index 0000000..4ea168a
--- /dev/null
+++ b/m4/vararrays.m4
@@ -0,0 +1,35 @@
+# Check for variable-length arrays.
+
+#serial 2
+
+# From Paul Eggert
+
+# Copyright (C) 2001, 2009-2011 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+AC_DEFUN([AC_C_VARARRAYS],
+[
+  AC_CACHE_CHECK([for variable-length arrays],
+    ac_cv_c_vararrays,
+    [AC_TRY_COMPILE(
+       [],
+       [static int x; char a[++x]; a[sizeof a - 1] = 0; return a[0];],
+       ac_cv_c_vararrays=yes,
+       ac_cv_c_vararrays=no)])
+  if test $ac_cv_c_vararrays = yes; then
+    AC_DEFINE([HAVE_C_VARARRAYS], [1],
+      [Define to 1 if C supports variable-length arrays.])
+  fi
+])