2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnSource]{Main pass of renamer}
9 rnHsType, rnLHsType, rnLHsTypes, rnContext,
10 rnHsSigType, rnHsTypeFVs, rnConDeclFields, rnLPred,
12 -- Precence related stuff
13 mkOpAppRn, mkNegAppRn, mkOpFormRn, mkConOpPatRn,
14 checkPrecMatch, checkSectionPrec,
16 -- Splice related stuff
20 import {-# SOURCE #-} RnExpr( rnLExpr )
22 import {-# SOURCE #-} TcSplice( runQuasiQuoteType )
27 import RdrHsSyn ( extractHsRhoRdrTyVars )
28 import RnHsSyn ( extractHsTyNames )
29 import RnHsDoc ( rnLHsDoc, rnMbLHsDoc )
34 import TypeRep ( funTyConName )
39 import BasicTypes ( compareFixity, funTyFixity, negateFixity,
40 Fixity(..), FixityDirection(..) )
43 import Control.Monad ( unless )
45 #include "HsVersions.h"
48 These type renamers are in a separate module, rather than in (say) RnSource,
49 to break several loop.
51 %*********************************************************
53 \subsection{Renaming types}
55 %*********************************************************
58 rnHsTypeFVs :: SDoc -> LHsType RdrName -> RnM (LHsType Name, FreeVars)
59 rnHsTypeFVs doc_str ty = do
60 ty' <- rnLHsType doc_str ty
61 return (ty', extractHsTyNames ty')
63 rnHsSigType :: SDoc -> LHsType RdrName -> RnM (LHsType Name)
64 -- rnHsSigType is used for source-language type signatures,
65 -- which use *implicit* universal quantification.
66 rnHsSigType doc_str ty
67 = rnLHsType (text "In the type signature for" <+> doc_str) ty
70 rnHsType is here because we call it from loadInstDecl, and I didn't
71 want a gratuitous knot.
74 rnLHsType :: SDoc -> LHsType RdrName -> RnM (LHsType Name)
75 rnLHsType doc = wrapLocM (rnHsType doc)
77 rnHsType :: SDoc -> HsType RdrName -> RnM (HsType Name)
79 rnHsType doc (HsForAllTy Implicit _ ctxt ty) = do
80 -- Implicit quantifiction in source code (no kinds on tyvars)
81 -- Given the signature C => T we universally quantify
82 -- over FV(T) \ {in-scope-tyvars}
83 name_env <- getLocalRdrEnv
85 mentioned = extractHsRhoRdrTyVars ctxt ty
87 -- Don't quantify over type variables that are in scope;
88 -- when GlasgowExts is off, there usually won't be any, except for
90 -- class C a where { op :: a -> a }
91 forall_tyvars = filter (not . (`elemLocalRdrEnv` name_env) . unLoc) mentioned
92 tyvar_bndrs = userHsTyVarBndrs forall_tyvars
94 rnForAll doc Implicit tyvar_bndrs ctxt ty
96 rnHsType doc (HsForAllTy Explicit forall_tyvars ctxt tau) = do
97 -- Explicit quantification.
98 -- Check that the forall'd tyvars are actually
99 -- mentioned in the type, and produce a warning if not
101 mentioned = map unLoc (extractHsRhoRdrTyVars ctxt tau)
102 forall_tyvar_names = hsLTyVarLocNames forall_tyvars
104 -- Explicitly quantified but not mentioned in ctxt or tau
105 warn_guys = filter ((`notElem` mentioned) . unLoc) forall_tyvar_names
107 mapM_ (forAllWarn doc tau) warn_guys
108 rnForAll doc Explicit forall_tyvars ctxt tau
110 rnHsType _ (HsTyVar tyvar) = do
111 tyvar' <- lookupOccRn tyvar
112 return (HsTyVar tyvar')
114 -- If we see (forall a . ty), without foralls on, the forall will give
115 -- a sensible error message, but we don't want to complain about the dot too
116 -- Hence the jiggery pokery with ty1
117 rnHsType doc ty@(HsOpTy ty1 (L loc op) ty2)
119 do { ops_ok <- xoptM Opt_TypeOperators
122 else do { addErr (opTyErr op ty)
123 ; return (mkUnboundName op) } -- Avoid double complaint
124 ; let l_op' = L loc op'
125 ; fix <- lookupTyFixityRn l_op'
126 ; ty1' <- rnLHsType doc ty1
127 ; ty2' <- rnLHsType doc ty2
128 ; mkHsOpTyRn (\t1 t2 -> HsOpTy t1 l_op' t2) op' fix ty1' ty2' }
130 rnHsType doc (HsParTy ty) = do
131 ty' <- rnLHsType doc ty
134 rnHsType doc (HsBangTy b ty)
135 = do { ty' <- rnLHsType doc ty
136 ; return (HsBangTy b ty') }
138 rnHsType doc (HsRecTy flds)
139 = do { flds' <- rnConDeclFields doc flds
140 ; return (HsRecTy flds') }
142 rnHsType doc (HsFunTy ty1 ty2) = do
143 ty1' <- rnLHsType doc ty1
144 -- Might find a for-all as the arg of a function type
145 ty2' <- rnLHsType doc ty2
146 -- Or as the result. This happens when reading Prelude.hi
147 -- when we find return :: forall m. Monad m -> forall a. a -> m a
149 -- Check for fixity rearrangements
150 mkHsOpTyRn HsFunTy funTyConName funTyFixity ty1' ty2'
152 rnHsType doc (HsListTy ty) = do
153 ty' <- rnLHsType doc ty
154 return (HsListTy ty')
156 rnHsType doc (HsKindSig ty k)
157 = do { kind_sigs_ok <- xoptM Opt_KindSignatures
158 ; unless kind_sigs_ok (addErr (kindSigErr ty))
159 ; ty' <- rnLHsType doc ty
160 ; return (HsKindSig ty' k) }
162 rnHsType doc (HsPArrTy ty) = do
163 ty' <- rnLHsType doc ty
164 return (HsPArrTy ty')
166 -- Unboxed tuples are allowed to have poly-typed arguments. These
167 -- sometimes crop up as a result of CPR worker-wrappering dictionaries.
168 rnHsType doc (HsTupleTy tup_con tys) = do
169 tys' <- mapM (rnLHsType doc) tys
170 return (HsTupleTy tup_con tys')
172 rnHsType doc (HsAppTy ty1 ty2) = do
173 ty1' <- rnLHsType doc ty1
174 ty2' <- rnLHsType doc ty2
175 return (HsAppTy ty1' ty2')
177 rnHsType doc (HsPredTy pred) = do
178 pred' <- rnPred doc pred
179 return (HsPredTy pred')
181 rnHsType _ (HsSpliceTy sp _ k)
182 = do { (sp', fvs) <- rnSplice sp -- ToDo: deal with fvs
183 ; return (HsSpliceTy sp' fvs k) }
185 rnHsType doc (HsDocTy ty haddock_doc) = do
186 ty' <- rnLHsType doc ty
187 haddock_doc' <- rnLHsDoc haddock_doc
188 return (HsDocTy ty' haddock_doc')
191 rnHsType _ ty@(HsQuasiQuoteTy _) = pprPanic "Can't do quasiquotation without GHCi" (ppr ty)
193 rnHsType doc (HsQuasiQuoteTy qq) = do { ty <- runQuasiQuoteType qq
194 ; rnHsType doc (unLoc ty) }
196 rnHsType _ (HsCoreTy ty) = return (HsCoreTy ty)
199 rnLHsTypes :: SDoc -> [LHsType RdrName]
200 -> IOEnv (Env TcGblEnv TcLclEnv) [LHsType Name]
201 rnLHsTypes doc tys = mapM (rnLHsType doc) tys
206 rnForAll :: SDoc -> HsExplicitFlag -> [LHsTyVarBndr RdrName]
207 -> LHsContext RdrName -> LHsType RdrName -> RnM (HsType Name)
209 rnForAll doc _ [] (L _ []) (L _ ty) = rnHsType doc ty
210 -- One reason for this case is that a type like Int#
211 -- starts off as (HsForAllTy Nothing [] Int), in case
212 -- there is some quantification. Now that we have quantified
213 -- and discovered there are no type variables, it's nicer to turn
214 -- it into plain Int. If it were Int# instead of Int, we'd actually
215 -- get an error, because the body of a genuine for-all is
218 rnForAll doc exp forall_tyvars ctxt ty
219 = bindTyVarsRn forall_tyvars $ \ new_tyvars -> do
220 new_ctxt <- rnContext doc ctxt
221 new_ty <- rnLHsType doc ty
222 return (HsForAllTy exp new_tyvars new_ctxt new_ty)
223 -- Retain the same implicit/explicit flag as before
224 -- so that we can later print it correctly
226 rnConDeclFields :: SDoc -> [ConDeclField RdrName] -> RnM [ConDeclField Name]
227 rnConDeclFields doc fields = mapM (rnField doc) fields
229 rnField :: SDoc -> ConDeclField RdrName -> RnM (ConDeclField Name)
230 rnField doc (ConDeclField name ty haddock_doc)
231 = do { new_name <- lookupLocatedTopBndrRn name
232 ; new_ty <- rnLHsType doc ty
233 ; new_haddock_doc <- rnMbLHsDoc haddock_doc
234 ; return (ConDeclField new_name new_ty new_haddock_doc) }
237 %*********************************************************
239 \subsection{Contexts and predicates}
241 %*********************************************************
244 rnContext :: SDoc -> LHsContext RdrName -> RnM (LHsContext Name)
245 rnContext doc = wrapLocM (rnContext' doc)
247 rnContext' :: SDoc -> HsContext RdrName -> RnM (HsContext Name)
248 rnContext' doc ctxt = mapM (rnLPred doc) ctxt
250 rnLPred :: SDoc -> LHsPred RdrName -> RnM (LHsPred Name)
251 rnLPred doc = wrapLocM (rnPred doc)
253 rnPred :: SDoc -> HsPred RdrName
254 -> IOEnv (Env TcGblEnv TcLclEnv) (HsPred Name)
255 rnPred doc (HsClassP clas tys)
256 = do { clas_name <- lookupOccRn clas
257 ; tys' <- rnLHsTypes doc tys
258 ; return (HsClassP clas_name tys')
260 rnPred doc (HsEqualP ty1 ty2)
261 = do { ty1' <- rnLHsType doc ty1
262 ; ty2' <- rnLHsType doc ty2
263 ; return (HsEqualP ty1' ty2')
265 rnPred doc (HsIParam n ty)
266 = do { name <- newIPNameRn n
267 ; ty' <- rnLHsType doc ty
268 ; return (HsIParam name ty')
273 %************************************************************************
275 Fixities and precedence parsing
277 %************************************************************************
279 @mkOpAppRn@ deals with operator fixities. The argument expressions
280 are assumed to be already correctly arranged. It needs the fixities
281 recorded in the OpApp nodes, because fixity info applies to the things
282 the programmer actually wrote, so you can't find it out from the Name.
284 Furthermore, the second argument is guaranteed not to be another
285 operator application. Why? Because the parser parses all
286 operator appications left-associatively, EXCEPT negation, which
287 we need to handle specially.
288 Infix types are read in a *right-associative* way, so that
293 mkHsOpTyRn rearranges where necessary. The two arguments
294 have already been renamed and rearranged. It's made rather tiresome
295 by the presence of ->, which is a separate syntactic construct.
299 -- Building (ty1 `op1` (ty21 `op2` ty22))
300 mkHsOpTyRn :: (LHsType Name -> LHsType Name -> HsType Name)
301 -> Name -> Fixity -> LHsType Name -> LHsType Name
304 mkHsOpTyRn mk1 pp_op1 fix1 ty1 (L loc2 (HsOpTy ty21 op2 ty22))
305 = do { fix2 <- lookupTyFixityRn op2
306 ; mk_hs_op_ty mk1 pp_op1 fix1 ty1
307 (\t1 t2 -> HsOpTy t1 op2 t2)
308 (unLoc op2) fix2 ty21 ty22 loc2 }
310 mkHsOpTyRn mk1 pp_op1 fix1 ty1 (L loc2 (HsFunTy ty21 ty22))
311 = mk_hs_op_ty mk1 pp_op1 fix1 ty1
312 HsFunTy funTyConName funTyFixity ty21 ty22 loc2
314 mkHsOpTyRn mk1 _ _ ty1 ty2 -- Default case, no rearrangment
315 = return (mk1 ty1 ty2)
318 mk_hs_op_ty :: (LHsType Name -> LHsType Name -> HsType Name)
319 -> Name -> Fixity -> LHsType Name
320 -> (LHsType Name -> LHsType Name -> HsType Name)
321 -> Name -> Fixity -> LHsType Name -> LHsType Name -> SrcSpan
323 mk_hs_op_ty mk1 op1 fix1 ty1
324 mk2 op2 fix2 ty21 ty22 loc2
325 | nofix_error = do { precParseErr (op1,fix1) (op2,fix2)
326 ; return (mk1 ty1 (L loc2 (mk2 ty21 ty22))) }
327 | associate_right = return (mk1 ty1 (L loc2 (mk2 ty21 ty22)))
328 | otherwise = do { -- Rearrange to ((ty1 `op1` ty21) `op2` ty22)
329 new_ty <- mkHsOpTyRn mk1 op1 fix1 ty1 ty21
330 ; return (mk2 (noLoc new_ty) ty22) }
332 (nofix_error, associate_right) = compareFixity fix1 fix2
335 ---------------------------
336 mkOpAppRn :: LHsExpr Name -- Left operand; already rearranged
337 -> LHsExpr Name -> Fixity -- Operator and fixity
338 -> LHsExpr Name -- Right operand (not an OpApp, but might
342 -- (e11 `op1` e12) `op2` e2
343 mkOpAppRn e1@(L _ (OpApp e11 op1 fix1 e12)) op2 fix2 e2
345 = do precParseErr (get_op op1,fix1) (get_op op2,fix2)
346 return (OpApp e1 op2 fix2 e2)
348 | associate_right = do
349 new_e <- mkOpAppRn e12 op2 fix2 e2
350 return (OpApp e11 op1 fix1 (L loc' new_e))
352 loc'= combineLocs e12 e2
353 (nofix_error, associate_right) = compareFixity fix1 fix2
355 ---------------------------
356 -- (- neg_arg) `op` e2
357 mkOpAppRn e1@(L _ (NegApp neg_arg neg_name)) op2 fix2 e2
359 = do precParseErr (negateName,negateFixity) (get_op op2,fix2)
360 return (OpApp e1 op2 fix2 e2)
363 = do new_e <- mkOpAppRn neg_arg op2 fix2 e2
364 return (NegApp (L loc' new_e) neg_name)
366 loc' = combineLocs neg_arg e2
367 (nofix_error, associate_right) = compareFixity negateFixity fix2
369 ---------------------------
371 mkOpAppRn e1 op1 fix1 e2@(L _ (NegApp _ _)) -- NegApp can occur on the right
372 | not associate_right -- We *want* right association
373 = do precParseErr (get_op op1, fix1) (negateName, negateFixity)
374 return (OpApp e1 op1 fix1 e2)
376 (_, associate_right) = compareFixity fix1 negateFixity
378 ---------------------------
380 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
381 = ASSERT2( right_op_ok fix (unLoc e2),
382 ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
384 return (OpApp e1 op fix e2)
386 ----------------------------
387 get_op :: LHsExpr Name -> Name
388 get_op (L _ (HsVar n)) = n
389 get_op other = pprPanic "get_op" (ppr other)
391 -- Parser left-associates everything, but
392 -- derived instances may have correctly-associated things to
393 -- in the right operarand. So we just check that the right operand is OK
394 right_op_ok :: Fixity -> HsExpr Name -> Bool
395 right_op_ok fix1 (OpApp _ _ fix2 _)
396 = not error_please && associate_right
398 (error_please, associate_right) = compareFixity fix1 fix2
402 -- Parser initially makes negation bind more tightly than any other operator
403 -- And "deriving" code should respect this (use HsPar if not)
404 mkNegAppRn :: LHsExpr id -> SyntaxExpr id -> RnM (HsExpr id)
405 mkNegAppRn neg_arg neg_name
406 = ASSERT( not_op_app (unLoc neg_arg) )
407 return (NegApp neg_arg neg_name)
409 not_op_app :: HsExpr id -> Bool
410 not_op_app (OpApp _ _ _ _) = False
413 ---------------------------
414 mkOpFormRn :: LHsCmdTop Name -- Left operand; already rearranged
415 -> LHsExpr Name -> Fixity -- Operator and fixity
416 -> LHsCmdTop Name -- Right operand (not an infix)
419 -- (e11 `op1` e12) `op2` e2
420 mkOpFormRn a1@(L loc (HsCmdTop (L _ (HsArrForm op1 (Just fix1) [a11,a12])) _ _ _))
423 = do precParseErr (get_op op1,fix1) (get_op op2,fix2)
424 return (HsArrForm op2 (Just fix2) [a1, a2])
427 = do new_c <- mkOpFormRn a12 op2 fix2 a2
428 return (HsArrForm op1 (Just fix1)
429 [a11, L loc (HsCmdTop (L loc new_c) [] placeHolderType [])])
430 -- TODO: locs are wrong
432 (nofix_error, associate_right) = compareFixity fix1 fix2
435 mkOpFormRn arg1 op fix arg2 -- Default case, no rearrangment
436 = return (HsArrForm op (Just fix) [arg1, arg2])
439 --------------------------------------
440 mkConOpPatRn :: Located Name -> Fixity -> LPat Name -> LPat Name
443 mkConOpPatRn op2 fix2 p1@(L loc (ConPatIn op1 (InfixCon p11 p12))) p2
444 = do { fix1 <- lookupFixityRn (unLoc op1)
445 ; let (nofix_error, associate_right) = compareFixity fix1 fix2
447 ; if nofix_error then do
448 { precParseErr (unLoc op1,fix1) (unLoc op2,fix2)
449 ; return (ConPatIn op2 (InfixCon p1 p2)) }
451 else if associate_right then do
452 { new_p <- mkConOpPatRn op2 fix2 p12 p2
453 ; return (ConPatIn op1 (InfixCon p11 (L loc new_p))) } -- XXX loc right?
454 else return (ConPatIn op2 (InfixCon p1 p2)) }
456 mkConOpPatRn op _ p1 p2 -- Default case, no rearrangment
457 = ASSERT( not_op_pat (unLoc p2) )
458 return (ConPatIn op (InfixCon p1 p2))
460 not_op_pat :: Pat Name -> Bool
461 not_op_pat (ConPatIn _ (InfixCon _ _)) = False
464 --------------------------------------
465 checkPrecMatch :: Name -> MatchGroup Name -> RnM ()
466 -- Check precedence of a function binding written infix
467 -- eg a `op` b `C` c = ...
468 -- See comments with rnExpr (OpApp ...) about "deriving"
470 checkPrecMatch op (MatchGroup ms _)
473 check (L _ (Match (L l1 p1 : L l2 p2 :_) _ _))
474 = setSrcSpan (combineSrcSpans l1 l2) $
475 do checkPrec op p1 False
479 -- This can happen. Consider
482 -- The infix flag comes from the first binding of the group
483 -- but the second eqn has no args (an error, but not discovered
484 -- until the type checker). So we don't want to crash on the
487 checkPrec :: Name -> Pat Name -> Bool -> IOEnv (Env TcGblEnv TcLclEnv) ()
488 checkPrec op (ConPatIn op1 (InfixCon _ _)) right = do
489 op_fix@(Fixity op_prec op_dir) <- lookupFixityRn op
490 op1_fix@(Fixity op1_prec op1_dir) <- lookupFixityRn (unLoc op1)
492 inf_ok = op1_prec > op_prec ||
493 (op1_prec == op_prec &&
494 (op1_dir == InfixR && op_dir == InfixR && right ||
495 op1_dir == InfixL && op_dir == InfixL && not right))
498 info1 = (unLoc op1, op1_fix)
499 (infol, infor) = if right then (info, info1) else (info1, info)
500 unless inf_ok (precParseErr infol infor)
505 -- Check precedence of (arg op) or (op arg) respectively
506 -- If arg is itself an operator application, then either
507 -- (a) its precedence must be higher than that of op
508 -- (b) its precedency & associativity must be the same as that of op
509 checkSectionPrec :: FixityDirection -> HsExpr RdrName
510 -> LHsExpr Name -> LHsExpr Name -> RnM ()
511 checkSectionPrec direction section op arg
513 OpApp _ op fix _ -> go_for_it (get_op op) fix
514 NegApp _ _ -> go_for_it negateName negateFixity
518 go_for_it arg_op arg_fix@(Fixity arg_prec assoc) = do
519 op_fix@(Fixity op_prec _) <- lookupFixityRn op_name
520 unless (op_prec < arg_prec
521 || (op_prec == arg_prec && direction == assoc))
522 (sectionPrecErr (op_name, op_fix)
523 (arg_op, arg_fix) section)
526 Precedence-related error messages
529 precParseErr :: (Name, Fixity) -> (Name, Fixity) -> RnM ()
530 precParseErr op1@(n1,_) op2@(n2,_)
531 | isUnboundName n1 || isUnboundName n2
532 = return () -- Avoid error cascade
534 = addErr $ hang (ptext (sLit "Precedence parsing error"))
535 4 (hsep [ptext (sLit "cannot mix"), ppr_opfix op1, ptext (sLit "and"),
537 ptext (sLit "in the same infix expression")])
539 sectionPrecErr :: (Name, Fixity) -> (Name, Fixity) -> HsExpr RdrName -> RnM ()
540 sectionPrecErr op@(n1,_) arg_op@(n2,_) section
541 | isUnboundName n1 || isUnboundName n2
542 = return () -- Avoid error cascade
544 = addErr $ vcat [ptext (sLit "The operator") <+> ppr_opfix op <+> ptext (sLit "of a section"),
545 nest 4 (sep [ptext (sLit "must have lower precedence than that of the operand,"),
546 nest 2 (ptext (sLit "namely") <+> ppr_opfix arg_op)]),
547 nest 4 (ptext (sLit "in the section:") <+> quotes (ppr section))]
549 ppr_opfix :: (Name, Fixity) -> SDoc
550 ppr_opfix (op, fixity) = pp_op <+> brackets (ppr fixity)
552 pp_op | op == negateName = ptext (sLit "prefix `-'")
553 | otherwise = quotes (ppr op)
556 %*********************************************************
560 %*********************************************************
563 forAllWarn :: SDoc -> LHsType RdrName -> Located RdrName
564 -> TcRnIf TcGblEnv TcLclEnv ()
565 forAllWarn doc ty (L loc tyvar)
566 = ifDOptM Opt_WarnUnusedMatches $
567 addWarnAt loc (sep [ptext (sLit "The universally quantified type variable") <+> quotes (ppr tyvar),
568 nest 4 (ptext (sLit "does not appear in the type") <+> quotes (ppr ty))]
572 opTyErr :: RdrName -> HsType RdrName -> SDoc
573 opTyErr op ty@(HsOpTy ty1 _ _)
574 = hang (ptext (sLit "Illegal operator") <+> quotes (ppr op) <+> ptext (sLit "in type") <+> quotes (ppr ty))
577 extra | op == dot_tv_RDR && forall_head ty1
580 = ptext (sLit "Use -XTypeOperators to allow operators in types")
582 forall_head (L _ (HsTyVar tv)) = tv == forall_tv_RDR
583 forall_head (L _ (HsAppTy ty _)) = forall_head ty
584 forall_head _other = False
585 opTyErr _ ty = pprPanic "opTyErr: Not an op" (ppr ty)
588 %*********************************************************
592 %*********************************************************
598 h = ...$(thing "f")...
600 The splice can expand into literally anything, so when we do dependency
601 analysis we must assume that it might mention 'f'. So we simply treat
602 all locally-defined names as mentioned by any splice. This is terribly
603 brutal, but I don't see what else to do. For example, it'll mean
604 that every locally-defined thing will appear to be used, so no unused-binding
605 warnings. But if we miss the dependency, then we might typecheck 'h' before 'f',
606 and that will crash the type checker because 'f' isn't in scope.
608 Currently, I'm not treating a splice as also mentioning every import,
609 which is a bit inconsistent -- but there are a lot of them. We might
610 thereby get some bogus unused-import warnings, but we won't crash the
611 type checker. Not very satisfactory really.
614 rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars)
615 rnSplice (HsSplice n expr)
616 = do { checkTH expr "splice"
618 ; n' <- newLocalBndrRn (L loc n)
619 ; (expr', fvs) <- rnLExpr expr
621 -- Ugh! See Note [Splices] above
622 ; lcl_rdr <- getLocalRdrEnv
623 ; gbl_rdr <- getGlobalRdrEnv
624 ; let gbl_names = mkNameSet [gre_name gre | gre <- globalRdrEnvElts gbl_rdr,
626 lcl_names = mkNameSet (occEnvElts lcl_rdr)
628 ; return (HsSplice n' expr', fvs `plusFV` lcl_names `plusFV` gbl_names) }
630 checkTH :: Outputable a => a -> String -> RnM ()
632 checkTH _ _ = return () -- OK
634 checkTH e what -- Raise an error in a stage-1 compiler
635 = addErr (vcat [ptext (sLit "Template Haskell") <+> text what <+>
636 ptext (sLit "illegal in a stage-1 compiler"),