NAME¶
yacc —
an LALR(1) parser
generator
SYNOPSIS¶
yacc |
[-dlrtvy]
[-b
file_prefix]
[-o
output_filename]
[-p
symbol_prefix]
filename |
DESCRIPTION¶
The
yacc utility reads the grammar specification in the file
filename and generates an LR(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. The
yacc utility
normally writes the parse tables and the driver routine to the file
y.tab.c.
The following options are available:
- -b
file_prefix
- Change the prefix prepended to the output file names to the
string denoted by file_prefix. The default prefix is
the character y.
- -d
- Cause the header file y.tab.h to be
written.
- -l
- If the -l option is not specified,
yacc will insert #line directives in the generated code.
The #line directives let the C compiler relate errors in the generated
code to the user's original code. If the -l option is
specified, yacc will not insert the #line directives.
Any #line directives specified by the user will be retained.
- -o
output_filename
- Cause yacc to write the generated code to
output_filename instead of the default file,
y.tab.c.
- -p
symbol_prefix
- Change the prefix prepended to yacc-generated symbols to
the string denoted by symbol_prefix. The default
prefix is the string yy.
- -r
- Cause yacc to produce separate files for
code and tables. The code file is named y.code.c, and
the tables file is named y.tab.c.
- -t
- Change the preprocessor directives generated by
yacc so that debugging statements will be incorporated
in the compiled code.
- -v
- Cause a human-readable description of the generated parser
to be written to the file y.output.
- -y
- NOOP for bison compatibility. yacc is
already designed to be POSIX yacc compatible.
ENVIRONMENT¶
TMPDIR
- Name of directory where temporary files are to be
created.
TABLES¶
The names of the tables generated by this version of
yacc are
yylhs,
yylen,
yydefred,
yydgoto,
yysindex,
yyrindex,
yygindex,
yytable, and
yycheck. Two additional tables,
yyname and
yyrule, are created if
YYDEBUG
is defined and non-zero.
FILES¶
- y.code.c
-
- y.tab.c
-
- y.tab.h
-
- y.output
-
- /tmp/yacc.aXXXXXXXXXX
-
- /tmp/yacc.tXXXXXXXXXX
-
- /tmp/yacc.uXXXXXXXXXX
-
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.
SEE ALSO¶
yyfix(1)
STANDARDS¶
The
yacc utility conforms to
IEEE Std 1003.2
(“POSIX.2”).
HISTORY¶
A
yacc command appeared in PWB UNIX.