How can I tell Bison I also expect reduce-reduce conflicts?

Question

My C#-ish toy grammar now has its first reduce-reduce conflicts! I'm so proud of me.

It seems all right to me, however (I switched off to a GLR parser for the occasion). The problem is, while I know the %expect directive can shut up Bison about shift/reduce conflicts, I can't find the equivalent for reduce/reduce conflicts. So what should I use to make it silent about my 3 shift/reduces and my 2 reduce/reduces?

If you can, grab the Dragon book "Compilers: Principles, Tools & Techniques" by Aho et al and "Modern Compiler Implementation in C" — Aiden Bell
Well, the Dragon Book's kind of expensive for my poor student status. :/ Especially since I'm doing it purely as a hobby, and I certainly won't have classes about compilers before several years. — zneak

Aiden Bell Aiden Bell · Accepted Answer · 2010-01-18T19:46:28

From the GNU Bison documentation, found here

For normal LALR(1) parsers, reduce/reduce conflicts are more serious, and should be eliminated entirely. Bison will always report reduce/reduce conflicts for these parsers. With GLR parsers, however, both kinds of conflicts are routine; otherwise, there would be no need to use GLR parsing. Therefore, it is also possible to specify an expected number of reduce/reduce conflicts in GLR parsers, using the declaration:
 %expect-rr n

How can I tell Bison I also expect reduce-reduce conflicts?

1 Answers