Date: Thu, 5 Dec 1996 19:13:37 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: hackers@freebsd.org Subject: Yacc -p<NAME> is broken Message-ID: <199612060213.TAA21534@phaeton.artisoft.com>
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When you generate a y.tab.h file using yacc -p<NAME>... ie:
yacc -v -p<NAME>
In the file y.tab.h, you get:
...
extern YYSTYPE <NAME>lval;
In reality, you should get:
...
#define yylval <NAME>lval
extern YYSTYPE yylval;
This is because lex grammars frequently include y.tab.h:
%{
#include "y.tab.h"
#include <math.h>
#include <string.h>
...
%}
%%
...
and the value of yylval in the lexer is dependent on the value in the
yacc grammar -- which is dependent on the -p<NAME> parameter (in y.tab.c,
there is a:
#define yylval <NAME>lval
Frequently, if you are mixing grammars, you have a -P<NAME> on the lex
to go with the -p<NAME> on the yacc...
Regards,
Terry Lambert
terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.
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