BISON(1)

NAME
bison - GNU Project parser generator (yacc replacement)

SYNOPSIS
bison [ -b file-prefix ] [ --file-prefix=file-prefix ] [ -d ] [ --defines=defines-file ] [ -g ] [ --graph=graph-file ] [ -k ] [ --token-table ] [ -l ] [ --no-lines ] [ -n ] [ --no-parser ] [ -o outfile ] [ --output-file=outfile ] [ -p prefix ] [ --name-prefix=prefix ] [ -t ] [ --debug ] [ -v ] [ --verbose ] [ -V ] [ --version ] [ -y ] [ --yacc ] [ -h ] [ --help ] [ --fixed-output-files ] 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 versions parse.tab.c.

This description of the options that can be given to bison is adapted from the node Invocation in the bison.texinfo 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 =.

  OPTIONS

-b file-prefix

--file-prefix=file-prefix
    Specify a prefix to use for all bison output file names. The names are chosen as if the input file were named file-prefix.c.

-d
    Write an extra output file containing macro definitions for the token type names defined in the grammar and the semantic value type YYSTYPE, as well as a few extern variable declarations.

    If the parser output file is named name.c then this file is named name.h.

    This output file is essential if you wish to put the definition of yylex in a separate source file, because yylex needs to be able to refer to token type codes and the variable yylval.

--defines=defines-file
    The behaviour of --defines is the same than -d option. The only difference is that it has an optionnal argument which is the name of the output filename.

-g
    Output a VCG definition of the LALR(1) grammar automaton computed by Bison. If the grammar file is foo.y , the VCG output file will be foo.vcg.

--graph=graph-file
    The behaviour of --graph is the same than -g option. The only difference is that it has an optionnal argument which is the name of the output graph filename.

-k

--token-table
    This switch causes the name.tab.c output to include a list of token names in order by their token numbers; this is defined in the array yytname. Also generated are #defines for YYNTOKENS, YYNNTS, YYNRULES, and YYNSTATES.

-l

--no-lines
    Don't put any #line preprocessor commands in the parser file. Ordinarily bison puts them in the parser file so that the C compiler and debuggers will associate errors with your source file, the grammar file. This option causes them to associate errors with the parser file, treating it an independent source file in its own right.

-n

--no-parser
    Do not generate the parser code into the output; generate only declarations. The generated name.tab.c file will have only constant declarations. In addition, a name.act file is generated containing a switch statement body containing all the translated actions.

-o outfile

--output-file=outfile
    Specify the name outfile for the parser file.

    The other output files' names are constructed from outfile as described under the -v and -d switches.

-p prefix

--name-prefix=prefix
    Rename the external symbols used in the parser so that they start with prefix instead of yy. The precise list of symbols renamed is yyparse, yylex, yyerror, yylval, yychar, and yydebug.

    For example, if you use -p c, the names become cparse, clex, and so on.

-t

--debug
    In the parser file, define the macro YYDEBUG to 1 if it is not already defined, so that the debugging facilities are compiled.

-v

--verbose
    Write an extra output file containing verbose descriptions of the parser states and what is done for each type of look-ahead token in that state.

    This file also describes all the conflicts, both those resolved by operator precedence and the unresolved ones.

    The file's name is made by removing .tab.c or .c from the parser output file name, and adding .output instead.

    Therefore, if the input file is foo.y, then the parser file is called foo.tab.c by default. As a consequence, the verbose output file is called foo.output.

-V

--version
    Print the version number of bison and exit.

-h

--help
    Print a summary of the options to bison and exit.

-y

--yacc

--fixed-output-files
    Equivalent to -o y.tab.c; the parser output file is called y.tab.c, and the other outputs are called y.output and y.tab.h. The purpose of this switch is to imitate yacc's output file name conventions. Thus, the following shell script can substitute for yacc:

    bison -y $*

FILES
/usr/local/share/bison/bison.simple    simple parser
/usr/local/share/bison/bison.hairy    complicated parser

ENVIRONMENT VARIABLES

BISON_SIMPLE
    If this is set, it specifies the location in which the bison.simple parser can be found.

BISON_HAIRY
    If this is set, it specifies the location in which the bison.hairy parser can be found.

SEE ALSO
yacc(1)
The Bison Reference Manual, included as the file bison.texinfo in the bison source distribution.

DIAGNOSTICS
Self explanatory.