> If you use bison instead of yacc this bug is not exposed. > > Is this correct behavior? I guess so. bison is quite different to yacc, see "info bison". llvm depends on bison and this is quite well documented. At http://llvm.org/releases/2.3/docs/GettingStarted.html#software it says "bison" and specifically which version of Bison you've to use.