Re: Error reporting with YACC (or Bison)

Hi Eric,


etetz@my-deja.com schrieb:
> When Bison encounters a syntax error it spits out "parse
> error". I want to give more descriptive error messages, such
> as "expecting semicolon after line 3". How would I go about this?


void yyerror(s)
        char * s;
{
        fprintf(stderr,"In file %s:\n",parsedFile);
        fprintf(stderr,"%s, ",s);
        fprintf(stderr,"Tokentext = <%s>\n",yytext);
}


parsedFile is a global variable. This solution does only work if there
is only one running instance of the parser and the lexer.


I haven't found/tried a way to provide line numbers yet but it seems
it is necessary to count the newlines in the lexer explicitly and to
store this info in yyloc with YYLTYPE .


Greetings,
Joachim

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