On 07/04/2012 01:28 PM, Eric Blake wrote: > On 07/04/2012 05:03 AM, Eric Blake wrote: > >> Would it also make sense to allow multiple calls to AC_CONFIG_MACRO_DIR >> to stack, as in: >> >> AC_CONFIG_MACRO_DIR([dir1]) >> AC_CONFIG_MACRO_DIR([dir2]) >> >> And should we mention that the first directory listed has special >> significance to other tools like libtool that use the first directory >> (and ignore subsequent directories) when first preparing a package with >> libtoolize? For that matter, I'd have to investigate whether libtoolize >> uses grep or autoconf tracing; > > Libtool 2.4.2 (the current release) uses grep tracing; but libtool > commit 2a71b02b has already converted over to m4 tracing. I'm not sure > if the m4 tracing will gracefully handle whitespace-separated > directories or multiple invocations, but the old code: > > - /AC_CONFIG_MACRO_DIR(/ { > - s,^.*AC_CONFIG_MACRO_DIR([[ ]*\([^])]*\).*$,ac_macro_dir=\1, > - p > - } > > definitely does NOT handle whitespace lists, and with multiple calls, > appears to reassign $ac_macro_dir to the last call rather than the first > (yuck). > > I think we're stuck for compatibility with providing a new macro for > listing subsidiary directories, and that users that plan to interact > with old libtool must use something like: > > AC_CONFIG_MACRO_DIR([dir1]) > AC_CONFIG_MACRO_DIRS([dir2 dir3]) > AC_CONFIG_MACRO_DIRS([dir4]) > > where the new macro can stack or take whitespace lists. The new macro > can also auto-call AC_CONFIG_MACRO_DIR() for its first argument for new > libtool that traces rather than using sed, > Hmm... Now that I think about it, this would cause aclocal to add such a directory twice to its search path (once because it's traced as an argument to AC_CONFIG_MACRO_DIRS, and once because it's traced as an argument to the auxiliary call to AC_CONFIG_MACRO_DIR you are proposing); not a big deal, but annoying. Instead, why not fix the development version of libtool to also support AC_CONFIG_MACRO_DIRS? There would be no regression, since such the libtoolize with tracing capabilities has never be released.
> but if you are porting to older libtool, explicitly spelling out the old > name is important. > Regards, Stefano