A primitive Perl script to run benches. Currently its only bench is the usual calculator: it has a lightweight processing part (but not null), so it is really emphasizing the cost of the whole parsing (including scanning and I/O).
Set the envvars BISON and CC to the programs and flags you want to use. They default to bison and gcc. To run a non-installed bison from a tarball built in _build, I suggest the following.
BISON=_build/tests/bison CC='gcc -O2' ./bench.pl
(The _build/tests/bison wrapper makes sure that _build/src/bison will use the tarballs' skeletons, not those already installed as a straightforward use of _build/src/bison would.)