[quake3-commits] [ioquake/ioq3] 0ad438: Make using Yacc optional, disabled by default

[Zack Middleton]

  Branch: refs/heads/master
  Home:   https://github.com/ioquake/ioq3
  Commit: 0ad4381a1185ed9ee964fbb8807eff66e8fe495d
      https://github.com/ioquake/ioq3/commit/0ad4381a1185ed9ee964fbb8807eff66e8fe495d
  Author: Zack Middleton <zturtleman at gmail.com>
  Date:   2016-07-11 (Mon, 11 Jul 2016)

  Changed paths:
    M Makefile
    M README.md

  Log Message:
  -----------
  Make using Yacc optional, disabled by default

A built-in GNU Make rule causes code/tools/lcc/lburg/gram.y to replace
gram.c if gram.y has a newer modified time. This causes git diff to
pick up changes to gram.c, which seems to have been manually modified
to fix warnings and may vary by Yacc used to create it. It also
requires installing a program to generate a file that already exists
in a usable state in the code repository.

So replace the built-in rule so it is only used if USE_YACC is 1
(defaults to 0). The Yacc executable name can be overriden using
`make YACC=yacc` like before.

I preferred to touch gram.c instead of installing Yacc because of the
problems it causes. It doesn't really seem like a good idea to recommend
others do that instead of disabling Yacc the Makefile though.