157 lines
4.4 KiB
Groff
157 lines
4.4 KiB
Groff
.\" $NetBSD: yacc.1,v 1.4 2011/09/10 21:29:04 christos Exp $
|
|
.\"
|
|
.\" Id: yacc.1,v 1.12 2011/09/08 00:40:44 tom Exp
|
|
.\"
|
|
.\" .TH YACC 1 "July\ 15,\ 1990"
|
|
.\" .UC 6
|
|
.TH YACC 1 "September 7, 2011" "Berkeley Yacc" "User Commands"
|
|
.SH NAME
|
|
Yacc \- an LALR(1) parser generator
|
|
.SH SYNOPSIS
|
|
.B yacc [ -dgilrtv ] [ \-b
|
|
.I file_prefix
|
|
.B ] [ \-p
|
|
.I symbol_prefix
|
|
.B ]
|
|
.I filename
|
|
.SH DESCRIPTION
|
|
.B Yacc
|
|
reads the grammar specification in the file
|
|
.I filename
|
|
and generates an LALR(1) parser for it.
|
|
The parsers consist of a set of LALR(1) parsing tables and a driver routine
|
|
written in the C programming language.
|
|
.B Yacc
|
|
normally writes the parse tables and the driver routine to the file
|
|
.IR y.tab.c.
|
|
.PP
|
|
The following options are available:
|
|
.TP
|
|
\fB\-b \fP\fIfile_prefix\fR
|
|
The
|
|
.B \-b
|
|
option changes the prefix prepended to the output file names to
|
|
the string denoted by
|
|
.IR file_prefix.
|
|
The default prefix is the character
|
|
.IR y.
|
|
.TP
|
|
.B \-d
|
|
The \fB-d\fR option causes the header file
|
|
.BR y.tab.h
|
|
to be written.
|
|
It contains #define's for the token identifiers.
|
|
.TP
|
|
.B \-g
|
|
The
|
|
.B \-g
|
|
option causes a graphical description of the generated LALR(1) parser to
|
|
be written to the file
|
|
.BR y.dot
|
|
in graphviz format, ready to be processed by dot(1).
|
|
.TP
|
|
.B \-i
|
|
The \fB-i\fR option causes a supplementary header file
|
|
.BR y.tab.i
|
|
to be written.
|
|
It contains extern declarations
|
|
and supplementary #define's as needed to map the conventional \fIyacc\fP
|
|
\fByy\fP-prefixed names to whatever the \fB-p\fP option may specify.
|
|
The code file, e.g., \fBy.tab.c\fP is modified to #include this file
|
|
as well as the \fBy.tab.h\fP file, enforcing consistent usage of the
|
|
symbols defined in those files.
|
|
.IP
|
|
The supplementary header file makes it simpler to separate compilation
|
|
of lex- and yacc-files.
|
|
.TP
|
|
.B \-l
|
|
If the
|
|
.B \-l
|
|
option is not specified,
|
|
.B yacc
|
|
will insert \fI#line\fP directives in the generated code.
|
|
The \fI#line\fP directives let the C compiler relate errors in the
|
|
generated code to the user's original code.
|
|
If the \fB-l\fR option is specified,
|
|
.B yacc
|
|
will not insert the \fI#line\fP directives.
|
|
\&\fI#line\fP directives specified by the user will be retained.
|
|
.TP
|
|
\fB\-o \fP\fIoutput_file\fR
|
|
specify the filename for the parser file.
|
|
If this option is not given, the output filename is
|
|
the file prefix concatenated with the file suffix, e.g., \fBy.tab.c\fP.
|
|
This overrides the \fB-p\fP option.
|
|
.TP
|
|
\fB\-p \fP\fIsymbol_prefix\fR
|
|
The
|
|
.B \-p
|
|
option changes the prefix prepended to yacc-generated symbols to
|
|
the string denoted by
|
|
.IR symbol_prefix.
|
|
The default prefix is the string
|
|
.BR yy.
|
|
.TP
|
|
.B \-P
|
|
create a reentrant parser, e.g., "%pure-parser".
|
|
.TP
|
|
.B \-r
|
|
The
|
|
.B \-r
|
|
option causes
|
|
.B yacc
|
|
to produce separate files for code and tables. The code file
|
|
is named
|
|
.IR y.code.c,
|
|
and the tables file is named
|
|
.IR y.tab.c.
|
|
The prefix "\fIy.\fP" can be overridden using the \fB\-b\fP option.
|
|
.TP
|
|
.B \-t
|
|
The
|
|
.B \-t
|
|
option changes the preprocessor directives generated by
|
|
.B yacc
|
|
so that debugging statements will be incorporated in the compiled code.
|
|
.TP
|
|
.B \-v
|
|
The
|
|
.B \-v
|
|
option causes a human-readable description of the generated parser to
|
|
be written to the file
|
|
.IR y.output.
|
|
.TP
|
|
.B \-V
|
|
print the version number to the standard output.
|
|
.SH EXTENSIONS
|
|
.B yacc
|
|
provides some extensions for compatibility with bison and other implementations
|
|
of yacc:
|
|
.TP
|
|
\fB %expect\fP \fInumber\fP
|
|
tell \fByacc\fP the expected number of shift/reduce conflicts.
|
|
That makes it only report the number if it differs.
|
|
.TP
|
|
\fB %expect-rr\fP \fInumber\fP
|
|
tell \fByacc\fP the expected number of reduce/reduce conflicts.
|
|
That makes it only report the number if it differs.
|
|
This is (unlike bison) allowable in LALR parsers.
|
|
.TP
|
|
\fB %lex-param\fP { \fIargument-declaration\fP }
|
|
By default, the lexer accepts no parameters, e.g., \fByylex()\fP.
|
|
Use this directive to add parameter declarations for your customized lexer.
|
|
.TP
|
|
\fB %parse-param\fP { \fIargument-declaration\fP }
|
|
By default, the parser accepts no parameters, e.g., \fByyparse()\fP.
|
|
Use this directive to add parameter declarations for your customized parser.
|
|
.TP
|
|
\fB %pure-parser\fP
|
|
Most variables (other than \fByydebug\fP and \fByynerrs\fP) are
|
|
allocated on the stack within \fByyparse\fP, making the parser reasonably
|
|
reentrant.
|
|
.
|
|
.SH DIAGNOSTICS
|
|
If there are rules that are never reduced, the number of such rules is
|
|
reported on standard error.
|
|
If there are any LALR(1) conflicts, the number of conflicts is reported
|
|
on standard error.
|