744171ddbf
Currently pstate_new does not set up its variables, this task is left to yypush_parse. This was probably to share more code with usual pull parsers, where these (local) variables are indeed initialized by yyparse. But as a consequence yyexpected_tokens crashes at the very beginning of the parse, since, for instance, the stacks are not even set up. See https://lists.gnu.org/r/bison-patches/2020-03/msg00001.html. The fix could have very simple, but the documentation actually makes it very clear that we can reuse a pstate for several parses: After yypush_parse returns a status other than YYPUSH_MORE, the parser instance yyps may be reused for a new parse. so we need to restore the parser to its pristine state so that (i) it is ready to run the next parse, (ii) it properly supports yyexpected_tokens for the next run. * data/skeletons/yacc.c (b4_initialize_parser_state_variables): New, extracted from the top of yyparse/yypush_parse. (yypstate_clear): New. (yypstate_new): Use it when push parsers are enabled. Define after the yyps macros so that we can use the same code as the regular pull parsers. (yyparse): Use it when push parsers are _not_ enabled. * examples/c/bistromathic/bistromathic.test: Check the completion on the beginning of the line.
This package contains the GNU Bison parser generator.
Installation
Build from git
Here are basic installation instructions for a repository checkout:
$ git submodule update --init
$ ./bootstrap
then proceed with the usual configure && make steps.
The file README-hacking.md is about building, modifying and checking Bison.
Build from tarball
See the file INSTALL for generic compilation and installation instructions.
Bison requires GNU m4 1.4.6 or later. See https://ftp.gnu.org/gnu/m4/m4-1.4.6.tar.gz.
Colored diagnostics
As an experimental feature, diagnostics are now colored, controlled by the
--color and --style options.
To use them, install the libtextstyle library before configuring Bison. It is available from https://alpha.gnu.org/gnu/gettext/, for instance https://alpha.gnu.org/pub/gnu/gettext/libtextstyle-0.20.5.tar.gz.
The option --color supports the following arguments:
- always, yes: Enable colors.
- never, no: Disable colors.
- auto, tty (default): Enable colors if the output device is a tty.
To customize the styles, create a CSS file, say bison-bw.css, similar to
/* bison-bw.css */
.warning { }
.error { font-weight: 800; text-decoration: underline; }
.note { }
then invoke bison with --style=bison-bw.css, or set the BISON_STYLE
environment variable to bison-bw.css.
Relocatability
If you pass --enable-relocatable to configure, Bison is relocatable.
A relocatable program can be moved or copied to a different location on the file system. It can also be used through mount points for network sharing. It is possible to make symlinks to the installed and moved programs, and invoke them through the symlink.
See "Enabling Relocatability" in the documentation.
Internationalization
Bison supports two catalogs: one for Bison itself (i.e., for the maintainer-side parser generation), and one for the generated parsers (i.e., for the user-side parser execution). The requirements between both differ: bison needs ngettext, the generated parsers do not. To simplify the build system, neither are installed if ngettext is not supported, even if generated parsers could have been localized. See http://lists.gnu.org/archive/html/bug-bison/2009-08/msg00006.html for more details.
Questions
See the section FAQ in the documentation (doc/bison.info) for frequently
asked questions. The documentation is also available in PDF and HTML,
provided you have a recent version of Texinfo installed: run make pdf or
make html.
If you have questions about using Bison and the documentation does not answer them, please send mail to help-bison@gnu.org.
Bug reports
Please send bug reports to bug-bison@gnu.org. Be sure to include the
version number from bison --version, and a complete, self-contained test
case in each bug report.
Copyright statements
For any copyright year range specified as YYYY-ZZZZ in this package, note that the range specifies every single year in that closed interval.