+# should the build process be restricted to only building
+# the documentation?
+AC_MSG_CHECKING(whether to build documentation ONLY)
+AC_ARG_ENABLE([documentation],
+ [AS_HELP_STRING([--enable-documentation], [only build the documentation])],
+ [doc_only=${enableval}],
+ [doc_only=no])
+AC_MSG_RESULT($doc_only)
+if test "x$doc_only" = "xyes"
+then
+ AM_CONDITIONAL([DOC_ONLY],true)
+ AC_DEFINE([DOC_ONLY],[1],[Building the documentation])
+else
+ AM_CONDITIONAL([DOC_ONLY],false)
+ AC_DEFINE([DOC_ONLY],[0],[Canonical compilation])
+fi
+