-%*********************************************************
-%* *
- Splices
-%* *
-%*********************************************************
-
-Note [Splices]
-~~~~~~~~~~~~~~
-Consider
- f = ...
- h = ...$(thing "f")...
-
-The splice can expand into literally anything, so when we do dependency
-analysis we must assume that it might mention 'f'. So we simply treat
-all locally-defined names as mentioned by any splice. This is terribly
-brutal, but I don't see what else to do. For example, it'll mean
-that every locally-defined thing will appear to be used, so no unused-binding
-warnings. But if we miss the dependency, then we might typecheck 'h' before 'f',
-and that will crash the type checker because 'f' isn't in scope.
-
-Currently, I'm not treating a splice as also mentioning every import,
-which is a bit inconsistent -- but there are a lot of them. We might
-thereby get some bogus unused-import warnings, but we won't crash the
-type checker. Not very satisfactory really.
-
-\begin{code}
-rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars)
-rnSplice (HsSplice n expr)
- = do { checkTH expr "splice"
- ; loc <- getSrcSpanM
- ; [n'] <- newLocalsRn [L loc n]
- ; (expr', fvs) <- rnLExpr expr
-
- -- Ugh! See Note [Splices] above
- ; lcl_rdr <- getLocalRdrEnv
- ; gbl_rdr <- getGlobalRdrEnv
- ; let gbl_names = mkNameSet [gre_name gre | gre <- globalRdrEnvElts gbl_rdr,
- isLocalGRE gre]
- lcl_names = mkNameSet (occEnvElts lcl_rdr)
-
- ; return (HsSplice n' expr', fvs `plusFV` lcl_names `plusFV` gbl_names) }
-
-checkTH :: Outputable a => a -> String -> RnM ()
-#ifdef GHCI
-checkTH _ _ = returnM () -- OK
-#else
-checkTH e what -- Raise an error in a stage-1 compiler
- = addErr (vcat [ptext (sLit "Template Haskell") <+> text what <+>
- ptext (sLit "illegal in a stage-1 compiler"),
- nest 2 (ppr e)])
-#endif
-\end{code}