4.3BSD - /usr/man/cat1/yacc.0

YACC(1)                                                                YACC(1)


NAME
       yacc - yet another compiler-compiler

SYNOPSIS
       yacc [ -vd ] grammar

DESCRIPTION
       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.

       The output file, y.tab.c, must be compiled by the C compiler to produce
       a  program  yyparse.  This program must be loaded with the lexical ana‐
       lyzer program, yylex, as well as main and yyerror,  an  error  handling
       routine.  These routines must be supplied by the user; Lex(1) is useful
       for creating lexical analyzers usable by yacc.

       If the -v flag is given, the file y.output is prepared, which  contains
       a description of the parsing tables and a report on conflicts generated
       by ambiguities in the grammar.

       If the -d flag is used, the file y.tab.h is generated with  the  define
       statements  that  associate  the  yacc-assigned  ‘token codes’ with the
       user-declared ‘token names’.   This  allows  source  files  other  than
       y.tab.c to access the token codes.

FILES
       y.output
       y.tab.c
       y.tab.h             defines for token names
       yacc.tmp, yacc.acts temporary files
       /usr/lib/yaccpar    parser prototype for C programs

SEE ALSO
       lex(1)
       LR  Parsing  by  A.  V. Aho and S. C. Johnson, Computing Surveys, June,
       1974.
       YACC - Yet Another Compiler Compiler by S. C. Johnson.

DIAGNOSTICS
       The number of reduce-reduce and shift-reduce conflicts is  reported  on
       the  standard  output;  a more detailed report is found in the y.output
       file.  Similarly, if some rules are not reachable from the  start  sym‐
       bol, this is also reported.

BUGS
       Because file names are fixed, at most one yacc process can be active in
       a given directory at a time.


7th Edition                     April 29, 1985                         YACC(1)