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This is used to help the user catch cases where some value gets ovewritten by a new one. This should not happen, as this will probably leak. Unfortunately this uncovered a bug in the C++ parser itself: the lookahead value was not destroyed between two calls to yylex. For instance if the previous lookahead was a std::string, and then an int, then the value of the std::string was correctly taken (i.e., the lookahead was now an empty string), but std::string structure itself was not reclaimed. This is now done in variant::build(other&) (which is used to take the value of the lookahead): other is not only stolen from its value, it is also destroyed. This incurs a new performance penalty of a few percent, and union becomes faster again. * data/lalr1-fusion.cc (variant::build(other&)): Destroy other. (b4_variant_if): New. (variant::built): New. Use it whereever the status of the variant changes. * etc/bench.pl.in: Check the penalty of %define assert.
A directory of tools provided to people using CVS Bison. None of
these is distributed.
* bench.pl
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.)
--
Copyright (C) 2006 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
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