+AC_CHECK_PROG(GDB,gdb,yes,no)
+
+dnl =================================================================
+dnl debug, gcc and gdb support
+dnl =================================================================
+
+AC_ARG_WITH(debug,
+ [ --with-debug Enable debug mode],
+ [
+ if test "x$withval" != "$xno" ; then
+ if test $ac_cv_prog_cc_g = yes; then
+ if test "$GCC" = yes; then
+ if test "$GDB"; then
+ CFLAGS="-ggdb"
+ else
+ CFLAGS="-g"
+ fi
+ CFLAGS="$CFLAGS -Wshadow -Wconversion"
+ else
+ CFLAGS="-g"
+ fi
+ fi
+ CFLAGS="$CFLAGS -D_DEBUG"
+ fi
+ ],
+ [
+ if test "$GCC" = yes; then
+ CFLAGS="-O2"
+ else
+ CFLAGS=
+ fi
+ ]
+)
+
+dnl =================================================================
+dnl additional gcc flags
+dnl =================================================================
+dnl
+if test "$GCC"; then
+ CFLAGS="-pipe $CFLAGS"
+fi
+