Re: yyerror() location tracking

[Joel E. Denny]

On Sat, 16 Jan 2010, Tom Stellard wrote:

> I am trying to add line numbers to my parser's error messages.  I have
> included the options, %locations and %define api.pure in my bison
> definition file, but it seems to be generating yyerror with this signature:
> yyerror(const char *msg);
> instead of the signature I am expecting:
> yyerror (YYLTYPE *locp, const char * msg)
> I have attached the bison definition file I am trying to use.
> Thanks.

The section of the manual you want is:

  
http://www.gnu.org/software/bison/manual/html_node/Error-Reporting.html#Error-Reporting

As you'll read there, to convince the deterministic parser in C to pass a 
location to yyerror, you need to specify %define api.pure, at least one 
%lex-param, and at least one %parse-param.  The %lex-param and 
%parse-param can be the same.

The yyerror prototype is confusing.  We've been considering ways to 
alleviate this problem, but we're not done yet.