Back in 2006, gnulib-tool added support to generate the variable LIB<FOO>_LIBDEPS that could be used in Makefile.am to pull in any libraries required by gnulib but not the main program. http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=a262d09e
However, this doesn't seem to work unless the module description takes pains to edit gl_libdeps. And right now, only crypto/gc, striconv, and striconveh do so. This bit me in M4, where strtod now triggers a replacement that requires POW_LIB (-lm) on many more platforms than what it used to do, so I had to edit my Makefile.am to add $(POW_LIB) to m4_LDADD even though it was already using $(LIBM4_LIBDEPS). On the other hand, there is the more recent addition of the Link: directive in modules, which was added to make gnulib-tool output mention that clients of a gnulib library might need to add $(POW_LIB) to their Makefile.am. Would it be possible to make the existence of the Link: directive smart enough to auto- update the gl_libdeps magic so POW_LIB and friends get added to LIB<FOO>_LIBDEPS? That way, projects that are okay with using the simpler $(LIB<FOO>_LIBDEPS) notation will not need any Makefile.am edits, no matter what dependent library changes are required as gnulib is updated. -- Eric Blake
