Some quick comments. I'm in a hurry. And before I forget: thanks for working on this.
* LIBOBJDIR seems worthy to document from the Autoconf user perspective. Non-automake might also benefit from this; and we should avoid using undocumented interfaces in Automake. * The Automake manual should be updated at least in two places: - the place where it documents all the macros that can affect its behavior (your patch causes AC_CONFIG_LIBOBJ_DIR to have a stronger semantic when used with Automake than when used with only Autoconf). - the section about how LIBOBJS is used. * The comment in _AC_LIBOBJS_NORMALIZE seems misleading to me, because LIBOBJDIR is unrelated to the macro AC_CONFIG_LIBOBJ_DIR as far as Autoconf is concerned. AC_CONFIG_LIBOBJ_DIR specifies where the *sources* files are. LIBOBJDIR is a prefix variable the user can use to relocate the *object* files. This is not necessary the same place. * Autoconf needs to be adjusted to reflect the fact that Automake scans a new macro. See the comment above the %traced variable you modified in scan_autoconf_trace. * Better write ${LIBOBJDIR} instead of $(LIBOBJDIR) in @LIBOBJS@ (for the same reason we use ${prefix}, etc.) * Use $PERL, not perl. * AFAICT your patch assumes that users use option `subdir-objects' when using @LIBOBJS@ remotely. I think we should also support the other case. I suggest you don't bother with the last point unless it looks easy to you. I'll probably find some time this week-end or next week. -- Alexandre Duret-Lutz