Re: patch to fix bad interaction between Bison 1.75b and flex

[Akim Demaille]

| I installed the following patch.
| 2002-12-13  Paul Eggert  <address@hidden>
| 
|       Fix a bad interaction with flex 2.5.23 reported by Bruce Lilly in
|       <http://mail.gnu.org/pipermail/bug-bison/2002-November/001929.html>.
|       * data/yacc.c (YYLTYPE, struct yyltype): Do not define unless
|       locations are requested.
|       (union yyalloc): Do not depend on YYLTYPE_IS_TRIVIAL unless
|       locations are requested.

I don't understand how a Bison symbol, completely unknown to the
scanner (such as yylval or yylloc) can interact here.