MARPA_LINKAGE seems to break many installations

[jeffreykegler]

@jddurand I brought the latest Libmarpa into Marpa::R2 developer's version and the MARPA_LINKAGE change seems to break things on a lot of systems. An example is in this log. Maybe I should back this change out. Suggestions?

[jddurand]

@jeffreykegler this is because the generated sources are missing extern keywords, i.e.:

• marpa.c from Marpa-R2-11.002_000:

  # 17051 "./marpa.w"
           const int marpa_major_version;
  const int marpa_minor_version;
  const int marpa_micro_version;
  ...
  # 576 "./marpa.w"
  
  const int marpa_major_version= 11;
  const int marpa_minor_version= 0;
  const int marpa_micro_version= 1;

• marpa.c from Marpa-R2-10.000000

  
  # 16805 "./marpa.w"
  extern const int marpa_major_version;
  extern const int marpa_minor_version;
  extern const int marpa_micro_version;
  ...
  # 571 "./marpa.w"

const int marpa_major_version= 9; const int marpa_minor_version= 0; const int marpa_micro_version= 3;

[jeffreykegler]

@jddurand The change happens in one of your commits: https://github.com/jeffreykegler/libmarpa/commit/85001583fda9b4f90490ed5e131e1ddee84fa297.

Any suggestions what to do here? It's tempting to just back the whole thing out, as too high-risk. You did warn me that the change was experimental.

[jddurand]

I made a comment in this commit. This is experimental, sure, though IMHO if you look at a marpa.c generated with a marpa.w that takes into account my comment, and find that the only difference are those "extern" thingy, this ought to work.

Still, this remain experimental, as you said.

[jeffreykegler]

I think, regretfully, I will back this commit out. A CPANtesters release can take weeks or even months to go on obscure systems, making experiments of this kind a real problem. The cost-benefit ratio just doesn't work for this one. Sorry.

[jeffreykegler]

I did the back-out in commits https://github.com/jeffreykegler/libmarpa/commit/4d4bf0959cfb542b726cb8b3990f9d046e92393f, https://github.com/jeffreykegler/libmarpa/commit/d02ef9090be85fe7668c72e70a24b739fa3940b7, and https://github.com/jeffreykegler/libmarpa/commit/2ee0c21999714901a0d852943110baad65512454. Testing looks a lot better. I will wait a few days, and if the testing continues to look good, schedule this issue for closing.

[jeffreykegler]

Testing looks good. Absent feedback to the contrary, I will close this issue after a couple of days.

[jeffreykegler]

Closed per https://github.com/jeffreykegler/libmarpa/issues/125#issuecomment-1358115456.