-AC_CHECK_TOOL(OBJCOPY, objcopy)
-AC_CHECK_TOOL(STRINGS, strings)
-AC_CHECK_TOOL(GPERF, gperf)
+AC_PATH_PROG([QUOTAON], [quotaon], [/sbin/quotaon])
+AC_PATH_PROG([QUOTACHECK], [quotacheck], [/sbin/quotacheck])
+
+# gtkdocize greps for '^GTK_DOC_CHECK', so it needs to be on its own line
+m4_ifdef([GTK_DOC_CHECK], [
+GTK_DOC_CHECK([1.18],[--flavour no-tmpl])
+], [AM_CONDITIONAL([ENABLE_GTK_DOC], [false])])
+
+AS_IF([test "x$enable_gtk_doc" = "xyes" -a "x$XSLTPROC" = x], [
+ AC_MSG_ERROR([*** GTK doc requested but xsltproc not found])
+])
+
+m4_ifdef([GOBJECT_INTROSPECTION_CHECK], [
+GOBJECT_INTROSPECTION_CHECK([1.31.1])
+], [AM_CONDITIONAL([HAVE_INTROSPECTION], [false])])
+
+AC_PATH_TOOL(OBJCOPY, objcopy)
+AC_PATH_TOOL(STRINGS, strings)
+AC_PATH_TOOL(GPERF, gperf)