BISON

Section: User Commands (1)
Updated: November 2020
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NAME

bison - GNU Project parser generator (yacc replacement)

SYNOPSIS

bison [,OPTION/]... ,FILE/

DESCRIPTION

Bison is a parser generator in the style of yacc(1). It should be upwardly compatible with input files designed for yacc.

Input files should follow the yacc convention of ending in .y. Unlike yacc, the generated files do not have fixed names, but instead use the prefix of the input file. Moreover, if you need to put C++ code in the input file, you can end his name by a C++-like extension (.ypp or .y++), then bison will follow your extension to name the output file (.cpp or .c++). For instance, a grammar description file named parse.yxx would produce the generated parser in a file named parse.tab.cxx, instead of yacc's y.tab.c or old Bison version's parse.tab.c.

This description of the options that can be given to bison is adapted from the node Invocation in the bison.texi manual, which should be taken as authoritative.

Bison supports both traditional single-letter options and mnemonic long option names. Long option names are indicated with -- instead of -. Abbreviations for option names are allowed as long as they are unique. When a long option takes an argument, like --file-prefix, connect the option name and the argument with =.

Generate a deterministic LR or generalized LR (GLR) parser employing LALR(1), IELR(1), or canonical LR(1) parser tables.

Mandatory arguments to long options are mandatory for short options too. The same is true for optional arguments.

Operation Modes:

-h, --help: display this help and exit
-V, --version: output version information and exit
--print-localedir: output directory containing locale-dependent data and exit
--print-datadir: output directory containing skeletons and XSLT and exit
-u, --update: apply fixes to the source grammar file and exit
-f, --feature[=,FEATURES/]: activate miscellaneous features

FEATURES is a list of comma separated words that can include:

caret, diagnostics-show-caret: show errors with carets
fixit, diagnostics-parseable-fixits: show machine-readable fixes
syntax-only: do not generate any file
all: all of the above
none: disable all of the above

Diagnostics:

-W, --warnings[=,CATEGORY/]: report the warnings falling in CATEGORY
--color[=,WHEN/]: whether to colorize the diagnostics
--style=,FILE/: specify the CSS FILE for colorizer diagnostics

Warning categories include:

conflicts-sr: S/R conflicts (enabled by default)
conflicts-rr: R/R conflicts (enabled by default)
counterexamples, cex: generate conflict counterexamples
dangling-alias: string aliases not attached to a symbol
deprecated: obsolete constructs
empty-rule: empty rules without %empty
midrule-values: unset or unused midrule values
precedence: useless precedence and associativity
yacc: incompatibilities with POSIX Yacc
other: all other warnings (enabled by default)
all: all the warnings except 'counterexamples', 'dangling-alias' and 'yacc'
no-CATEGORY: turn off warnings in CATEGORY
none: turn off all the warnings
error[=CATEGORY]: treat warnings as errors

WHEN can be one of the following:

always, yes: colorize the output
never, no: don't colorize the output
auto, tty: colorize if the output device is a tty

Tuning the Parser:

-L, --language=,LANGUAGE/: specify the output programming language
-S, --skeleton=,FILE/: specify the skeleton to use
-t, --debug: instrument the parser for tracing same as '-Dparse.trace'
--locations: enable location support
-D, --define=NAME[=,VALUE/]: similar to '%define NAME VALUE'
-F, --force-define=NAME[=,VALUE/]: override '%define NAME VALUE'
-p, --name-prefix=,PREFIX/: prepend PREFIX to the external symbols deprecated by '-Dapi.prefix={PREFIX}'
-l, --no-lines: don't generate '#line' directives
-k, --token-table: include a table of token names
-y, --yacc: emulate POSIX Yacc

Output Files:

--defines[=,FILE/]: also produce a header file
-d: likewise but cannot specify FILE (for POSIX Yacc)
-r, --report=,THINGS/: also produce details on the automaton
--report-file=,FILE/: write report to FILE
-v, --verbose: same as '--report=state'
-b, --file-prefix=,PREFIX/: specify a PREFIX for output files
-o, --output=,FILE/: leave output to FILE
-g, --graph[=,FILE/]: also output a graph of the automaton
-x, --xml[=,FILE/]: also output an XML report of the automaton
-M, --file-prefix-map=,OLD=NEW/ replace prefix OLD with NEW when writing file paths: in output files

THINGS is a list of comma separated words that can include:

states: describe the states
itemsets: complete the core item sets with their closure
lookaheads: explicitly associate lookahead tokens to items
solved: describe shift/reduce conflicts solving
counterexamples, cex: generate conflict counterexamples
all: include all the above information
none: disable the report

AUTHOR

Written by Robert Corbett and Richard Stallman.

REPORTING BUGS

Report bugs to <bug-bison@gnu.org>.
GNU Bison home page: <https://www.gnu.org/software/bison/>.
General help using GNU software: <http://www.gnu.org/gethelp/>.
For complete documentation, run: info bison.