1YACC(1) General Commands Manual YACC(1)
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6 yacc - yet another compiler-compiler
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9 yacc [ -vd ] grammar
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12 Yacc converts a context-free grammar into a set of tables for a simple
13 automaton which executes an LR(1) parsing algorithm. The grammar may
14 be ambiguous; specified precedence rules are used to break ambiguities.
15 The output file, y.tab.c, must be compiled by the C compiler to produce
17 a program yyparse. This program must be loaded with the lexical ana‐
18 lyzer program, yylex, as well as main and yyerror, an error handling
19 routine. These routines must be supplied by the user; Lex(1) is useful
20 for creating lexical analyzers usable by yacc.
21 If the -v flag is given, the file y.output is prepared, which contains
23 a description of the parsing tables and a report on conflicts generated
24 by ambiguities in the grammar.
25 If the -d flag is used, the file y.tab.h is generated with the define
27 statements that associate the yacc-assigned `token codes' with the
28 user-declared `token names'. This allows source files other than
29 y.tab.c to access the token codes.
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32 y.output
33 y.tab.c
34 y.tab.h defines for token names
35 yacc.tmp, yacc.acts temporary files
36 /usr/lib/yaccpar parser prototype for C programs
37 /lib/liby.a library with default `main' and `yyerror'
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40 lex(1)
41 LR Parsing by A. V. Aho and S. C. Johnson, Computing Surveys, June,
42 1974.
43 YACC - Yet Another Compiler Compiler by S. C. Johnson.
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46 The number of reduce-reduce and shift-reduce conflicts is reported on
47 the standard output; a more detailed report is found in the y.output
48 file. Similarly, if some rules are not reachable from the start sym‐
49 bol, this is also reported.
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52 Because file names are fixed, at most one yacc process can be active in
53 a given directory at a time.
54 YACC(1)