.TH BISON 1 local

.SH NAME

bison \- GNU Project parser generator (yacc replacement)

.SH SYNOPSIS

.B bison

[

.BI \-b  " file-prefix"

] [

.BI \-\-file-prefix= file-prefix

] [

.B \-d

] [

.BI \-\-defines= defines-file

] [

.B \-g

] [

.BI \-\-graph= graph-file

] [

.B \-k

] [

.B \-\-token-table

] [

.B \-l

] [

.B \-\-no-lines

] [

.B \-n

] [

.B \-\-no-parser

] [

.BI \-o " outfile"

] [

.BI \-\-output-file= outfile

] [

.BI \-p " prefix"

] [

.BI \-\-name-prefix= prefix

] [

.B \-t

] [

.B \-\-debug

] [

.B \-v

] [

.B \-\-verbose

] [

.B \-V

] [

.B \-\-version

] [

.B \-y

] [

.B \-\-yacc

] [

.B \-h

] [

.B \-\-help

] [

.B \-\-fixed-output-files

]

file

.br

.B yacc

[

.I "similar options and operands"

]

.SH DESCRIPTION

.I Bison

is a parser generator in the style of

.IR yacc (1).

It should be upwardly compatible with input files designed

for

.IR yacc .

.PP

Input files should follow the

.I yacc

convention of ending in

.BR .y .

Unlike

.IR yacc ,

the generated files do not have fixed names, but instead use the prefix

of the input file.

Moreover, if you need to put

.I 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

.B parse.yxx

would produce the generated parser in a file named

.BR parse.tab.cxx ,

instead of

.IR yacc 's

.B y.tab.c

or old

.I Bison

version's

.BR parse.tab.c .

.PP

This description of the options that can be given to

.I bison

is adapted from the node

.B Invocation

in the

.B bison.texinfo

manual, which should be taken as authoritative.

.PP

.I Bison

supports both traditional single-letter options and mnemonic long

option names.  Long option names are indicated with

.B \-\-

instead of

.BR \- .

Abbreviations for option names are allowed as long as they

are unique.  When a long option takes an argument, like

.BR \-\-file-prefix ,

connect the option name and the argument with

.BR = .

.SS OPTIONS

.TP

.BI \-b " file-prefix"

.br

.ns

.TP

.BI \-\-file-prefix= file-prefix

Specify a prefix to use for all

.I bison

output file names.  The names are

chosen as if the input file were named

\fIfile-prefix\fP\fB.c\fP.

.TP

.B \-d

.br

.ns

Write an extra output file containing macro definitions for the token

type names defined in the grammar and the semantic value type

.BR YYSTYPE ,

as well as a few

.B extern

variable declarations.

.sp

If the parser output file is named

.IB name .c

then this file

is named

\fIname\fP\fB.h\fP.

.sp

This output file is essential if you wish to put the definition of

.B yylex

in a separate source file, because

.B yylex

needs to be able to refer to token type codes and the variable

.BR yylval .

.TP

.BI \-\-defines= defines-file

The behavior of

.B \-\-defines

is the same than

.B \-d

option.

The only difference is that it has an optional argument which is

the name of the output filename.

.TP

.BI \-g

.br

.ns

Output a VCG definition of the LALR(1) grammar automaton computed by

Bison.  If the grammar file is

.BR foo.y

, the VCG output file will be

.BR foo.vcg .

.TP

.BI \-\-graph= graph-file

The behavior of

.BI \-\-graph

is the same than

.BI \-g

option.  The only difference is that it has an optional argument which

is the name of the output graph filename.

.TP

.B \-k

.br

.ns

.TP

.B \-\-token-table

This switch causes the

.IB name .tab.c

output to include a list of

token names in order by their token numbers; this is defined in the array

.IR yytname .

Also generated

are #defines for

.IR YYNTOKENS ,

.IR YYNNTS ,

.IR YYNRULES ,

and

.IR YYNSTATES .

.TP

.B \-l

.br

.ns

.TP

.B \-\-no-lines

Don't put any

.B #line

preprocessor commands in the parser file.

Ordinarily

.I 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.

.TP

.B \-n

.br

.ns

.TP

.B \-\-no-parser

Do not generate the parser code into the output; generate only

declarations.  The generated

.IB name .tab.c

file will have only

constant declarations.  In addition, a

.IB name .act

file is

generated containing a switch statement body containing all the

translated actions.

.TP

.BI \-o " outfile"

.br

.ns

.TP

.BI \-\-output-file= outfile

Specify the name

.I outfile

for the parser file.

.sp

The other output files' names are constructed from

.I outfile

as described under the

.B \-v

and

.B \-d

switches.

.TP

.BI \-p " prefix"

.br

.ns

.TP

.BI \-\-name-prefix= prefix

Rename the external symbols used in the parser so that they start with

.I prefix

instead of

.BR yy .

The precise list of symbols renamed is

.BR yyparse ,

.BR yylex ,

.BR yyerror ,

.BR yylval ,

.BR yychar ,

and

.BR yydebug .

.sp

For example, if you use

.BR "\-p c" ,

the names become

.BR cparse ,

.BR clex ,

and so on.

.TP

.B \-t

.br

.ns

.TP

.B \-\-debug

In the parser file, define the macro

.B YYDEBUG

to 1 if it is not already defined,

so that the debugging facilities are compiled.

.TP

.B \-v

.br

.ns

.TP

.B \-\-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.

.sp

This file also describes all the conflicts, both those resolved by

operator precedence and the unresolved ones.

.sp

The file's name is made by removing

.B .tab.c

or

.B .c

from the parser output file name, and adding

.B .output

instead.

.sp

Therefore, if the input file is

.BR foo.y ,

then the parser file is called

.B foo.tab.c

by default.  As a consequence, the verbose

output file is called

.BR foo.output .

.TP

.B \-V

.br

.ns

.TP

.B \-\-version

Print the version number of

.I bison

and exit.

.TP

.B \-h

.br

.ns

.TP

.B \-\-help

Print a summary of the options to

.I bison

and exit.

.TP

.B \-y

.br

.ns

.TP

.B \-\-yacc

.br

.ns

.TP

.B \-\-fixed-output-files

Equivalent to

.BR "\-o y.tab.c" ;

the parser output file is called

.BR y.tab.c ,

and the other outputs are called

.B y.output

and

.BR y.tab.h .

The purpose of this switch is to imitate

.IR yacc 's

output file name conventions.

Thus, the following shell script can substitute for

.I yacc

and is often installed as

.IR yacc :

.sp

.RS

.ft B

bison \-y "$@"

.ft R

.sp

.RE

.SH SEE ALSO

.IR yacc (1)

.br

The

.IR "Bison Reference Manual" ,

included as the file

.B bison.texinfo

in the

.I bison

source distribution.

.SH DIAGNOSTICS

Self explanatory.