PWB1/usr/man/man1/yacc.1

.th YACC I 5/31/77
.sh NAME
yacc \*- yet another compiler-compiler
.sh SYNOPSIS
.bd yacc
[
.bd \*-vrd
]
[ grammar ]
.sh DESCRIPTION
.it Yacc
converts a context-free grammar into a set of
tables for a simple automaton which executes an LR(1) parsing
algorithm.
The grammar may be ambiguous;
specified precedence rules are used to break ambiguities.
.s3
The output is
.it y.tab.c,
which must be compiled by the C compiler
and loaded with any other routines
required (perhaps a lexical analyzer) and the
.it yacc
library:
.s3
	cc y.tab.c other.o \*-ly
.s3
If the
.bd \*-v
flag is given, the file
.it y.output
is prepared, which contains a description of the parsing tables
and a report on
conflicts generated by ambiguities in the grammar.
.s3
The
.bd \*-r
flag causes
.it yacc
to accept grammars with Ratfor actions,
and produce Ratfor output on
.it y.tab.r.
Typical usage is then
.s3
	rc y.tab.r other.o
.s3
If the \-\fBd\fP flag is used, the file
.it y.tab.h
is generated with the
.it define
statements that associate the
.it yacc\c
-assigned ``token codes'' with the user-declared ``token names''.
This allows source files other than
.it y.tab.c
to access the token codes.
.sh "SEE ALSO"
lex(I)
.br
.it "LR Parsing"
by A. V. Aho and S. C. Johnson,
Computing Surveys, June, 1974.
.br
.it "YACC \- Yet Another Compiler Compiler"
by S. C. Johnson.
.sh FILES
y.output
.br
y.tab.c
.br
y.tab.r			when ratfor output is obtained
.br
y.tab.h			defines for token names
.br
yacc.tmp, yacc.acts	temporary files
.br
/lib/liby.a		runtime library for compiler
.br
/usr/lib/yaccopar	parser prototype for C programs
.br
/usr/lib/yaccrpar	parser prototype for Ratfor programs
.sh DIAGNOSTICS
The number of reduce-reduce and shift-reduce conflicts
is reported on the standard output;
a more detailed report is
found in the
.it y.output
file.
.sh BUGS
Because file names are fixed, at most one
.it yacc
process can be active in a given directory at
a time.