Commit a556f688 authored by Bang Jun-Young's avatar Bang Jun-Young Committed by Alexandre Julliard

Add a workaround for a bug in byacc (again).

parent 1055481a
......@@ -423,6 +423,32 @@ resources
want_id = 1;
dont_want_id = 0;
}
/*
* The following newline rule will never get reduced because we never
* get the tNL token, unless we explicitely set the 'want_nl'
* flag, which we don't.
* The *ONLY* reason for this to be here is because Berkeley
* yacc (byacc), at least version 1.9, has a bug.
* (identified in the generated parser on the second
* line with:
* static char yysccsid[] = "@(#)yaccpar 1.9 (Berkeley) 02/21/93";
* )
* This extra rule fixes it.
* The problem is that the expression handling rule "expr: xpr"
* is not reduced on non-terminal tokens, defined above in the
* %token declarations. Token tNL is the only non-terminal that
* can occur. The error becomes visible in the language parsing
* rule below, which looks at the look-ahead token and tests it
* for tNL. However, byacc already generates an error upon reading
* the token instead of keeping it as a lookahead. The reason
* lies in the lack of a $default transition in the "expr : xpr . "
* state (currently state 25). It is probably ommitted because tNL
* is a non-terminal and the state contains 2 s/r conflicts. The
* state enumerates all possible transitions instead of using a
* $default transition.
* All in all, it is a bug in byacc. (period)
*/
| resources tNL
;
......
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