Nick Bowler <nbow...@draconx.ca> writes: > On 8/23/17, Mathieu Lirzin <m...@gnu.org> wrote: >> Michael Haubenwallner <michael.haubenwall...@ssi-schaefer.com> writes: >>> Another thought about the final "$(LIBOBJS): .../.dirstamp" Makefile >>> line: If I remember correctly, there have been (non-GNU) make >>> implementations thatchoke on this rule when LIBOBJS is an empty >>> variable: Am I wrong here, or is GNU make required anyway these days? >> >> GNU make is not required for current Automake version. I didn't find >> any reference of this issue with empty variable target in Autoconf >> "Portable Make programming" section [1] but if it is actually the case >> then it would be nice to find a solution for that. > > POSIX requires that target rules specify at least one target. At least > dmake will fail to parse the makefile if it contains an target rule with > no targets: > > % cat >Makefile <<'EOF' > FOO = > dummy: ; > $(FOO): ; > EOF > % dmake > dmake: Makefile: line 3: Error: -- Missing targets or attributes in rule > > If the target list is a macro which can reasonably be empty then one > solution is to add a bogus target name that won't be used anywhere > else, along the lines of: > > gobbledegook $(FOO): ;
Instead of this dummy target, I would rather prefer adding the dirstamp dependency for each explicit object file separately. this should be computed from the '%libsources' variable. However after a quick look in the code, it seems that this variable is not properly populated by the 'scan_autoconf_traces' subroutine. It only contains the files that are explicitely defined by scanning the AC_LIBSOURCE macro and not by AC_LIBOBJ or AC_LIBSOURCES in 'configure.ac'. Michael: Are you interested in looking into this? Thanks for your input. -- Mathieu Lirzin GPG: F2A3 8D7E EB2B 6640 5761 070D 0ADE E100 9460 4D37
