15.6 Upgrading From Version 2.13

The introduction of the previous section (see section 15.5 Upgrading From Version 1) perfectly suits this section....

Autoconf version 2.50 is mostly backward compatible with version 2.13. However, it introduces better ways to do some things, and doesn't support some of the ugly things in version 2.13. So, depending on how sophisticated your `configure.ac' files are, you might have to do some manual work in order to upgrade to version 2.50. This chapter points out some problems to watch for when upgrading. Also, perhaps your configure scripts could benefit from some of the new features in version 2.50; the changes are summarized in the file `NEWS' in the Autoconf distribution.

15.6.1 Changed Quotation		Broken code which used to work
15.6.2 New Macros		Interaction with foreign macros
15.6.3 Hosts and Cross-Compilation		Bugward compatibility kludges
15.6.4 AC_LIBOBJ vs. LIBOBJS		LIBOBJS is a forbidden token
15.6.5 AC_FOO_IFELSE vs. AC_TRY_FOO		A more generic scheme for testing sources