Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : master
http://hackage.haskell.org/trac/ghc/changeset/74d401860d6a28244b9a12fca844fe14a6a04274 >--------------------------------------------------------------- commit 74d401860d6a28244b9a12fca844fe14a6a04274 Author: Simon Peyton Jones <simo...@microsoft.com> Date: Fri Jan 4 10:30:53 2013 +0000 Switch on -XEmptyCase when renaming derived declarations Compiler-generated code can have empty cases >--------------------------------------------------------------- compiler/typecheck/TcDeriv.lhs | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs index 6eb9ded..10670f7 100644 --- a/compiler/typecheck/TcDeriv.lhs +++ b/compiler/typecheck/TcDeriv.lhs @@ -401,7 +401,9 @@ renameDeriv is_boot inst_infos bagBinds , emptyValBindsOut, usesOnly (plusFVs fvs)) } | otherwise - = discardWarnings $ -- Discard warnings about unused bindings etc + = discardWarnings $ -- Discard warnings about unused bindings etc + setXOptM Opt_EmptyCase $ -- Derived decls (for empty types) can have + -- case x of {} do { -- Bring the extra deriving stuff into scope -- before renaming the instances themselves _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
