bison(1) GNU Project parser generator (yacc replacement)


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


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, instead of yacc's or old Bison version's

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. IELR(1) and canonical LR(1) support is experimental.

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
output directory containing locale-dependent data
output directory containing skeletons and XSLT
-y, --yacc
emulate POSIX Yacc
-W, --warnings[=,CATEGORY/]
report the warnings falling in CATEGORY
-f, --feature[=,FEATURE/]
activate miscellaneous features


-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'
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


also produce a header file
likewise but cannot specify FILE (for POSIX Yacc)
-r, --report=,THINGS/
also produce details on the automaton
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 (the XML schema is experimental)

Warning categories include:

unset or unused midrule values
incompatibilities with POSIX Yacc
S/R conflicts (enabled by default)
R/R conflicts (enabled by default)
obsolete constructs
empty rules without %empty
useless precedence and associativity
all other warnings (enabled by default)
all the warnings except 'yacc'
turn off warnings in CATEGORY
turn off all the warnings
treat warnings as errors

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

describe the states
complete the core item sets with their closure
explicitly associate lookahead tokens to items
describe shift/reduce conflicts solving
include all the above information
disable the report

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

show errors with carets
all of the above
disable all of the above


Written by Robert Corbett and Richard Stallman.


Report bugs to <[email protected]>.
GNU Bison home page: <>.
General help using GNU software: <>.

Report translation bugs to <>.
For complete documentation, run: info bison.


Copyright © 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.