Sam Steingold <sds <at> gnu.org> writes: > Eric Blake wrote: > > any rate, using 'autoconf --trace=_CL_CLISP_REQUIRE_FEATURE_2' would show > > what the result of m4_toupper turns out to be in this case. > > running this: > autoconf --trace=CL_CLISP > hangs forever without any output. I'm _still_ interested in the alternative m4_map_args_w and --trace=_CL_CLISP_REQUIRE_FEATURE_2 behavior. So far, you have _only_ provided results for m4_foreach_w, using m4_pushdef, whereas my alternative suggestion of m4_map_args_w does not require the use of m4_pushdef, so I still wonder whether my alternative suggestion would better cope with m4_toupper's lack of quoting. > -[AC_CACHE_CHECK([for cl_feat in CLISP], [cl_cv_clisp_]cl_feat, > +[m4_pushdef([CL_FEAT], [m4_toupper([cl_feat])])dnl It's obvious why this particular patch attempt infloops - because you over- quoted m4_toupper, you are defining CL_FEAT to contain the contents: m4_toupper([cl_feat]) Thus, when you call a raw: CL_FEAT you end up invoking: m4_toupper([cl_feat]) which in turn expands to this (in autoconf 2.64, but not after I apply my patch for 2.65 to properly quote m4_toupper's result): CL_FEAT hence an infinite loop. And if you had tried: > +[m4_pushdef([CL_FEAT], m4_toupper([cl_feat]))dnl (note that the m4_toupper is intentionally NOT quoted), then you would be defining CL_FEAT as: CL_FEAT and still have an infinite loop. But if you went with what I suggested: > +[m4_pushdef([CL_FEAT], m4_toupper(cl_feat))dnl (now note that both m4_toupper and cl_feat are unquoted), you get CL_FEAT defined as the uppercase version of the contents of cl_feat; or, when cl_feat is ffi, then CL_FEAT would be FFI In other words, this is a case where you really DO want the macro cl_feat and m4_toupper expanded prior to calling m4_pushdef with the results. -- Eric Blake _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
