Hello, * Thomas Dickey wrote on Sun, Sep 05, 2010 at 03:09:20PM CEST: > On Sun, 5 Sep 2010, Russell Shaw wrote: > >Thomas Dickey wrote: > >>On Sun, 5 Sep 2010, Russell Shaw wrote: > >>>When should AC_CACHE_CHECK be used? Whenever the user uninstalls > >>>something, wouldn't the cache become invalid? > >> > >>...only if the user happened to uninstall something during the configure > >>process. After that, AC_CACHE_CHECK is irrelevant. > > > >But if the user uninstalls libfoo then later re-runs ./configure, > >won't libfoo still be assumed to be installed? > > sure. That sort of thing was why (for a long time) autoconf removed > the cache on startup. Now that you're mentioning it, I seem to recall > a recent undoing of that. I can't remember that either autoconf nor configure would remove config.cache, for any Autoconf >= 2.59. 'make distclean' from an automake-generated Makefile does that. But yes, you are supposed to not reuse the cache file after changing your system. With that in mind, AC_CACHE_CHECK should be used freely for any test that is expensive or should be overridable by the user (because she might know better), and that is amenable to single-entrance logic (i.e., isn't run in a loop) and a unique cache variable name. Cheers, Ralf _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
