README - bison - Git at Google

 GNU Bison is a general-purpose parser generator that converts an annotated
 context-free grammar into a deterministic LR or generalized LR (GLR) parser
 employing LALR(1) parser tables.  Bison can also generate IELR(1) or
 canonical LR(1) parser tables.  Once you are proficient with Bison, you can
 use it to develop a wide range of language parsers, from those used in
 simple desk calculators to complex programming languages.

 Bison is upward compatible with Yacc: all properly-written Yacc grammars
 work with Bison with no change.  Anyone familiar with Yacc should be able to
 use Bison with little trouble.  You need to be fluent in C, C++, D or Java
 programming in order to use Bison.

 Bison and the parsers it generates are portable, they do not require any
 specific compilers.

 GNU Bison's home page is https://gnu.org/software/bison/.

 # Installation
 ## Build from git
 The [README-hacking.md file](README-hacking.md) is about building, modifying
 and checking Bison.  See its "Working from the Repository" section to build
 Bison from the git repo.  Roughly, run:

     $ git submodule update --init
     $ ./bootstrap

 then proceed with the usual `configure && make` steps.

 ## Build from tarball
 See the [INSTALL 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.

 ## Running a non installed bison
 Once you ran `make`, you might want to toy with this fresh bison before
 installing it.  In that case, do not use `src/bison`: it would use the
 *installed* files (skeletons, etc.), not the local ones.  Use `tests/bison`.

 ## Colored diagnostics
 As an experimental feature, diagnostics are now colored, controlled by the
 `--color` and `--style` options.

 To use them, install the libtextstyle library, 0.20.5 or newer, before
 configuring Bison.  It is available from https://alpha.gnu.org/gnu/gettext/,
 for instance https://alpha.gnu.org/gnu/gettext/libtextstyle-0.20.5.tar.gz,
 or as part of Gettext 0.21 or newer, for instance
 https://ftp.gnu.org/gnu/gettext/gettext-0.21.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`.

 In some diagnostics, bison uses libtextstyle to emit special escapes to
 generate clickable hyperlinks.  The environment variable
 `NO_TERM_HYPERLINKS` can be used to suppress them.  This may be useful for
 terminal emulators which produce garbage output when they receive the escape
 sequence for a hyperlink. Currently (as of 2020), this affects some versions
 of emacs, guake, konsole, lxterminal, rxvt, yakuake.

 ## 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
 https://lists.gnu.org/r/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.

 <!--

 LocalWords:  parsers ngettext Texinfo pdf html YYYY ZZZZ ispell american md
 LocalWords:  MERCHANTABILITY GLR LALR IELR submodule init README src bw
 LocalWords:  Relocatability symlinks symlink

 Local Variables:
 mode: markdown
 fill-column: 76
 ispell-dictionary: "american"
 End:

 Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015, 2018-2022 Free
 Software Foundation, Inc.

 This file is part of GNU bison, the GNU Compiler Compiler.

 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
 any later version published by the Free Software Foundation; with no
 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
 Texts.  A copy of the license is included in the "GNU Free
 Documentation License" file as part of this distribution.

 -->
	GNU Bison is a general-purpose parser generator that converts an annotated
	context-free grammar into a deterministic LR or generalized LR (GLR) parser
	employing LALR(1) parser tables. Bison can also generate IELR(1) or
	canonical LR(1) parser tables. Once you are proficient with Bison, you can
	use it to develop a wide range of language parsers, from those used in
	simple desk calculators to complex programming languages.

	Bison is upward compatible with Yacc: all properly-written Yacc grammars
	work with Bison with no change. Anyone familiar with Yacc should be able to
	use Bison with little trouble. You need to be fluent in C, C++, D or Java
	programming in order to use Bison.

	Bison and the parsers it generates are portable, they do not require any
	specific compilers.

	GNU Bison's home page is https://gnu.org/software/bison/.

	# Installation
	## Build from git
	The [README-hacking.md file](README-hacking.md) is about building, modifying
	and checking Bison. See its "Working from the Repository" section to build
	Bison from the git repo. Roughly, run:

	$ git submodule update --init
	$ ./bootstrap

	then proceed with the usual `configure && make` steps.

	## Build from tarball
	See the [INSTALL 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.

	## Running a non installed bison
	Once you ran `make`, you might want to toy with this fresh bison before
	installing it. In that case, do not use `src/bison`: it would use the
	installed files (skeletons, etc.), not the local ones. Use `tests/bison`.

	## Colored diagnostics
	As an experimental feature, diagnostics are now colored, controlled by the
	`--color` and `--style` options.

	To use them, install the libtextstyle library, 0.20.5 or newer, before
	configuring Bison. It is available from https://alpha.gnu.org/gnu/gettext/,
	for instance https://alpha.gnu.org/gnu/gettext/libtextstyle-0.20.5.tar.gz,
	or as part of Gettext 0.21 or newer, for instance
	https://ftp.gnu.org/gnu/gettext/gettext-0.21.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`.

	In some diagnostics, bison uses libtextstyle to emit special escapes to
	generate clickable hyperlinks. The environment variable
	`NO_TERM_HYPERLINKS` can be used to suppress them. This may be useful for
	terminal emulators which produce garbage output when they receive the escape
	sequence for a hyperlink. Currently (as of 2020), this affects some versions
	of emacs, guake, konsole, lxterminal, rxvt, yakuake.

	## 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
	https://lists.gnu.org/r/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.

	<!--

	LocalWords: parsers ngettext Texinfo pdf html YYYY ZZZZ ispell american md
	LocalWords: MERCHANTABILITY GLR LALR IELR submodule init README src bw
	LocalWords: Relocatability symlinks symlink

	Local Variables:
	mode: markdown
	fill-column: 76
	ispell-dictionary: "american"
	End:

	Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015, 2018-2022 Free
	Software Foundation, Inc.

	This file is part of GNU bison, the GNU Compiler Compiler.

	Permission is granted to copy, distribute and/or modify this document
	under the terms of the GNU Free Documentation License, Version 1.3 or
	any later version published by the Free Software Foundation; with no
	Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
	Texts. A copy of the license is included in the "GNU Free
	Documentation License" file as part of this distribution.

	-->