=== modified file 'configure.ac'
--- configure.ac	2011-09-22 16:13:22 +0000
+++ configure.ac	2012-10-26 05:31:05 +0000
@@ -85,9 +85,17 @@
 dnl Check for which system.
 AC_CANONICAL_HOST
 
+
 dnl Checks for programs.
 AC_LANG(C)
-AC_PROG_CC
+case $host_os in
+    darwin* )
+        AC_PROG_CC([clang cc gcc])
+        ;;
+    * )
+        AC_PROG_CC
+esac
+
 AC_PROG_CPP
 AC_PROG_INSTALL
 AC_PROG_LN_S