Bison and Yacc Compatibility Problem

oulevon · 10-23-2005, 10:49 PM

Hi,

I'm writing a compiler for a subset of Pascal (Appendix A from the Dragon Book). I've been given the lex and yacc files to get me started. The pascal.y file works fine using yacc, but when I use bison, I get the following errors:

Code:

pascal.y:84: type clash (`' `symb') on default action
pascal.y:137: type clash (`' `symb') on default action
pascal.y:138: type clash (`' `symb') on default action
pascal.y:141: type clash (`' `symb') on default action
pascal.y:142: type clash (`' `symb') on default action
pascal.y:172: type clash (`' `symb') on default action
pascal.y:173: type clash (`' `symb') on default action
pascal.y:174: type clash (`' `symb') on default action

I'm not sure what these errors mean, and why I only get them in Bison and not in Yacc. Does anyone have any idea?

I can post the pascal.y file, but I thought maybe this is a common error between Bison and Yacc.

Thanks for any help.

oulevon · 10-23-2005, 10:56 PM

I think I may have found the source of the problem. I was using an older version of Bison. On a newer version it seems to work fine.