X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnExpr.lhs;h=11d44e3bad8b0796c65daf1d977b2b4e2f6b702d;hp=e78e942bf20b7e9da8417a65cde530f6142a5f71;hb=f6d254cccd3dc25fff9ff50c2e1bea52b10345e4;hpb=8401cdef44ef0877197f4cd978adae8798d0a8e7 diff --git a/compiler/rename/RnExpr.lhs b/compiler/rename/RnExpr.lhs index e78e942..11d44e3 100644 --- a/compiler/rename/RnExpr.lhs +++ b/compiler/rename/RnExpr.lhs @@ -16,43 +16,48 @@ module RnExpr ( #include "HsVersions.h" -import RnSource ( rnSrcDecls, rnSplice, checkTH ) -import RnBinds ( rnLocalBindsAndThen, rnValBinds, - rnMatchGroup, trimWith ) +#ifdef GHCI +import {-# SOURCE #-} TcSplice( runQuasiQuoteExpr ) +#endif /* GHCI */ + +import RnSource ( rnSrcDecls, findSplice ) +import RnBinds ( rnLocalBindsAndThen, rnLocalValBindsLHS, rnLocalValBindsRHS, + rnMatchGroup, makeMiniFixityEnv) import HsSyn -import RnHsSyn import TcRnMonad +import TcEnv ( thRnBrack ) import RnEnv -import HscTypes ( availNames ) -import RnNames ( getLocalDeclBinders, extendRdrEnvRn ) -import RnTypes ( rnHsTypeFVs, rnLPat, rnOverLit, rnPatsAndThen, rnLit, - mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec, - dupFieldErr, checkTupSize ) -import DynFlags ( DynFlag(..) ) +import RnTypes ( rnHsTypeFVs, rnSplice, checkTH, + mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec) +import RnPat +import DynFlags import BasicTypes ( FixityDirection(..) ) -import SrcLoc ( SrcSpan ) -import PrelNames ( thFAKE, hasKey, assertIdKey, assertErrorName, - loopAName, choiceAName, appAName, arrAName, composeAName, firstAName, - negateName, thenMName, bindMName, failMName ) +import PrelNames -import Name ( Name, nameOccName, nameIsLocalOrFrom ) +import Name import NameSet -import RdrName ( RdrName, extendLocalRdrEnv, lookupLocalRdrEnv, hideSomeUnquals ) +import RdrName import LoadIface ( loadInterfaceForName ) -import UniqFM ( isNullUFM ) -import UniqSet ( emptyUniqSet ) -import List ( nub ) -import Util ( isSingleton ) +import UniqSet +import Data.List +import Util ( isSingleton, snocView ) import ListSetOps ( removeDups ) -import Maybes ( expectJust ) import Outputable -import SrcLoc ( Located(..), unLoc, getLoc, cmpLocated ) +import SrcLoc import FastString - -import List ( unzip4 ) +import Control.Monad \end{code} +\begin{code} +-- XXX +thenM :: Monad a => a b -> (b -> a c) -> a c +thenM = (>>=) + +thenM_ :: Monad a => a b -> a c -> a c +thenM_ = (>>) +\end{code} + %************************************************************************ %* * \subsubsection{Expressions} @@ -63,7 +68,7 @@ import List ( unzip4 ) rnExprs :: [LHsExpr RdrName] -> RnM ([LHsExpr Name], FreeVars) rnExprs ls = rnExprs' ls emptyUniqSet where - rnExprs' [] acc = returnM ([], acc) + rnExprs' [] acc = return ([], acc) rnExprs' (expr:exprs) acc = rnLExpr expr `thenM` \ (expr', fvExpr) -> @@ -72,12 +77,8 @@ rnExprs ls = rnExprs' ls emptyUniqSet let acc' = acc `plusFV` fvExpr in - (grubby_seqNameSet acc' rnExprs') exprs acc' `thenM` \ (exprs', fvExprs) -> - returnM (expr':exprs', fvExprs) - --- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq -grubby_seqNameSet ns result | isNullUFM ns = result - | otherwise = result + acc' `seq` rnExprs' exprs acc' `thenM` \ (exprs', fvExprs) -> + return (expr':exprs', fvExprs) \end{code} Variables. We look up the variable and return the resulting name. @@ -88,152 +89,173 @@ rnLExpr = wrapLocFstM rnExpr rnExpr :: HsExpr RdrName -> RnM (HsExpr Name, FreeVars) +finishHsVar :: Name -> RnM (HsExpr Name, FreeVars) +-- Separated from rnExpr because it's also used +-- when renaming infix expressions +-- See Note [Adding the implicit parameter to 'assert'] +finishHsVar name + = do { ignore_asserts <- doptM Opt_IgnoreAsserts + ; if ignore_asserts || not (name `hasKey` assertIdKey) + then return (HsVar name, unitFV name) + else do { e <- mkAssertErrorExpr + ; return (e, unitFV name) } } + rnExpr (HsVar v) - = do name <- lookupOccRn v - ignore_asserts <- doptM Opt_IgnoreAsserts - finish_var ignore_asserts name - where - finish_var ignore_asserts name - | ignore_asserts || not (name `hasKey` assertIdKey) - = return (HsVar name, unitFV name) - | otherwise - = do { (e, fvs) <- mkAssertErrorExpr - ; return (e, fvs `addOneFV` name) } + = do name <- lookupOccRn v + finishHsVar name rnExpr (HsIPVar v) = newIPNameRn v `thenM` \ name -> - returnM (HsIPVar name, emptyFVs) + return (HsIPVar name, emptyFVs) rnExpr (HsLit lit@(HsString s)) = do { - opt_OverloadedStrings <- doptM Opt_OverloadedStrings + opt_OverloadedStrings <- xoptM Opt_OverloadedStrings ; if opt_OverloadedStrings then - rnExpr (HsOverLit (mkHsIsString s)) + rnExpr (HsOverLit (mkHsIsString s placeHolderType)) else -- Same as below rnLit lit `thenM_` - returnM (HsLit lit, emptyFVs) + return (HsLit lit, emptyFVs) } rnExpr (HsLit lit) = rnLit lit `thenM_` - returnM (HsLit lit, emptyFVs) + return (HsLit lit, emptyFVs) rnExpr (HsOverLit lit) = rnOverLit lit `thenM` \ (lit', fvs) -> - returnM (HsOverLit lit', fvs) + return (HsOverLit lit', fvs) rnExpr (HsApp fun arg) = rnLExpr fun `thenM` \ (fun',fvFun) -> rnLExpr arg `thenM` \ (arg',fvArg) -> - returnM (HsApp fun' arg', fvFun `plusFV` fvArg) - -rnExpr (OpApp e1 op _ e2) - = rnLExpr e1 `thenM` \ (e1', fv_e1) -> - rnLExpr e2 `thenM` \ (e2', fv_e2) -> - rnLExpr op `thenM` \ (op'@(L _ (HsVar op_name)), fv_op) -> - + return (HsApp fun' arg', fvFun `plusFV` fvArg) + +rnExpr (OpApp e1 (L op_loc (HsVar op_rdr)) _ e2) + = do { (e1', fv_e1) <- rnLExpr e1 + ; (e2', fv_e2) <- rnLExpr e2 + ; op_name <- setSrcSpan op_loc (lookupOccRn op_rdr) + ; (op', fv_op) <- finishHsVar op_name + -- NB: op' is usually just a variable, but might be + -- an applicatoin (assert "Foo.hs:47") -- Deal with fixity -- When renaming code synthesised from "deriving" declarations -- we used to avoid fixity stuff, but we can't easily tell any -- more, so I've removed the test. Adding HsPars in TcGenDeriv -- should prevent bad things happening. - lookupFixityRn op_name `thenM` \ fixity -> - mkOpAppRn e1' op' fixity e2' `thenM` \ final_e -> - - returnM (final_e, - fv_e1 `plusFV` fv_op `plusFV` fv_e2) + ; fixity <- lookupFixityRn op_name + ; final_e <- mkOpAppRn e1' (L op_loc op') fixity e2' + ; return (final_e, fv_e1 `plusFV` fv_op `plusFV` fv_e2) } +rnExpr (OpApp _ other_op _ _) + = failWith (vcat [ hang (ptext (sLit "Operator application with a non-variable operator:")) + 2 (ppr other_op) + , ptext (sLit "(Probably resulting from a Template Haskell splice)") ]) rnExpr (NegApp e _) = rnLExpr e `thenM` \ (e', fv_e) -> lookupSyntaxName negateName `thenM` \ (neg_name, fv_neg) -> mkNegAppRn e' neg_name `thenM` \ final_e -> - returnM (final_e, fv_e `plusFV` fv_neg) - -rnExpr (HsPar e) - = rnLExpr e `thenM` \ (e', fvs_e) -> - returnM (HsPar e', fvs_e) + return (final_e, fv_e `plusFV` fv_neg) +------------------------------------------ -- Template Haskell extensions -- Don't ifdef-GHCI them because we want to fail gracefully -- (not with an rnExpr crash) in a stage-1 compiler. rnExpr e@(HsBracket br_body) = checkTH e "bracket" `thenM_` rnBracket br_body `thenM` \ (body', fvs_e) -> - returnM (HsBracket body', fvs_e) + return (HsBracket body', fvs_e) -rnExpr e@(HsSpliceE splice) +rnExpr (HsSpliceE splice) = rnSplice splice `thenM` \ (splice', fvs) -> - returnM (HsSpliceE splice', fvs) + return (HsSpliceE splice', fvs) -rnExpr section@(SectionL expr op) - = rnLExpr expr `thenM` \ (expr', fvs_expr) -> - rnLExpr op `thenM` \ (op', fvs_op) -> - checkSectionPrec InfixL section op' expr' `thenM_` - returnM (SectionL expr' op', fvs_op `plusFV` fvs_expr) +#ifndef GHCI +rnExpr e@(HsQuasiQuoteE _) = pprPanic "Cant do quasiquotation without GHCi" (ppr e) +#else +rnExpr (HsQuasiQuoteE qq) + = runQuasiQuoteExpr qq `thenM` \ (L _ expr') -> + rnExpr expr' +#endif /* GHCI */ + +--------------------------------------------- +-- Sections +-- See Note [Parsing sections] in Parser.y.pp +rnExpr (HsPar (L loc (section@(SectionL {})))) + = do { (section', fvs) <- rnSection section + ; return (HsPar (L loc section'), fvs) } -rnExpr section@(SectionR op expr) - = rnLExpr op `thenM` \ (op', fvs_op) -> - rnLExpr expr `thenM` \ (expr', fvs_expr) -> - checkSectionPrec InfixR section op' expr' `thenM_` - returnM (SectionR op' expr', fvs_op `plusFV` fvs_expr) +rnExpr (HsPar (L loc (section@(SectionR {})))) + = do { (section', fvs) <- rnSection section + ; return (HsPar (L loc section'), fvs) } +rnExpr (HsPar e) + = do { (e', fvs_e) <- rnLExpr e + ; return (HsPar e', fvs_e) } + +rnExpr expr@(SectionL {}) + = do { addErr (sectionErr expr); rnSection expr } +rnExpr expr@(SectionR {}) + = do { addErr (sectionErr expr); rnSection expr } + +--------------------------------------------- rnExpr (HsCoreAnn ann expr) = rnLExpr expr `thenM` \ (expr', fvs_expr) -> - returnM (HsCoreAnn ann expr', fvs_expr) + return (HsCoreAnn ann expr', fvs_expr) rnExpr (HsSCC lbl expr) = rnLExpr expr `thenM` \ (expr', fvs_expr) -> - returnM (HsSCC lbl expr', fvs_expr) + return (HsSCC lbl expr', fvs_expr) rnExpr (HsTickPragma info expr) = rnLExpr expr `thenM` \ (expr', fvs_expr) -> - returnM (HsTickPragma info expr', fvs_expr) + return (HsTickPragma info expr', fvs_expr) rnExpr (HsLam matches) = rnMatchGroup LambdaExpr matches `thenM` \ (matches', fvMatch) -> - returnM (HsLam matches', fvMatch) + return (HsLam matches', fvMatch) rnExpr (HsCase expr matches) = rnLExpr expr `thenM` \ (new_expr, e_fvs) -> rnMatchGroup CaseAlt matches `thenM` \ (new_matches, ms_fvs) -> - returnM (HsCase new_expr new_matches, e_fvs `plusFV` ms_fvs) + return (HsCase new_expr new_matches, e_fvs `plusFV` ms_fvs) rnExpr (HsLet binds expr) = rnLocalBindsAndThen binds $ \ binds' -> rnLExpr expr `thenM` \ (expr',fvExpr) -> - returnM (HsLet binds' expr', fvExpr) + return (HsLet binds' expr', fvExpr) -rnExpr e@(HsDo do_or_lc stmts body _) - = do { ((stmts', body'), fvs) <- rnStmts do_or_lc stmts $ - rnLExpr body - ; return (HsDo do_or_lc stmts' body' placeHolderType, fvs) } +rnExpr (HsDo do_or_lc stmts _) + = do { ((stmts', _), fvs) <- rnStmts do_or_lc stmts (\ _ -> return ((), emptyFVs)) + ; return ( HsDo do_or_lc stmts' placeHolderType, fvs ) } rnExpr (ExplicitList _ exps) = rnExprs exps `thenM` \ (exps', fvs) -> - returnM (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name) + return (ExplicitList placeHolderType exps', fvs) rnExpr (ExplicitPArr _ exps) = rnExprs exps `thenM` \ (exps', fvs) -> - returnM (ExplicitPArr placeHolderType exps', fvs) + return (ExplicitPArr placeHolderType exps', fvs) -rnExpr e@(ExplicitTuple exps boxity) - = checkTupSize tup_size `thenM_` - rnExprs exps `thenM` \ (exps', fvs) -> - returnM (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name) +rnExpr (ExplicitTuple tup_args boxity) + = do { checkTupleSection tup_args + ; checkTupSize (length tup_args) + ; (tup_args', fvs) <- mapAndUnzipM rnTupArg tup_args + ; return (ExplicitTuple tup_args' boxity, plusFVs fvs) } where - tup_size = length exps - tycon_name = tupleTyCon_name boxity tup_size + rnTupArg (Present e) = do { (e',fvs) <- rnLExpr e; return (Present e', fvs) } + rnTupArg (Missing _) = return (Missing placeHolderType, emptyFVs) -rnExpr (RecordCon con_id _ (HsRecordBinds rbinds)) - = lookupLocatedOccRn con_id `thenM` \ conname -> - rnRbinds "construction" rbinds `thenM` \ (rbinds', fvRbinds) -> - returnM (RecordCon conname noPostTcExpr (HsRecordBinds rbinds'), - fvRbinds `addOneFV` unLoc conname) +rnExpr (RecordCon con_id _ rbinds) + = do { conname <- lookupLocatedOccRn con_id + ; (rbinds', fvRbinds) <- rnHsRecBinds (HsRecFieldCon (unLoc conname)) rbinds + ; return (RecordCon conname noPostTcExpr rbinds', + fvRbinds `addOneFV` unLoc conname) } -rnExpr (RecordUpd expr (HsRecordBinds rbinds) _ _) - = rnLExpr expr `thenM` \ (expr', fvExpr) -> - rnRbinds "update" rbinds `thenM` \ (rbinds', fvRbinds) -> - returnM (RecordUpd expr' (HsRecordBinds rbinds') placeHolderType placeHolderType, - fvExpr `plusFV` fvRbinds) +rnExpr (RecordUpd expr rbinds _ _ _) + = do { (expr', fvExpr) <- rnLExpr expr + ; (rbinds', fvRbinds) <- rnHsRecBinds HsRecFieldUpd rbinds + ; return (RecordUpd expr' rbinds' [] [] [], + fvExpr `plusFV` fvRbinds) } rnExpr (ExprWithTySig expr pty) = do { (pty', fvTy) <- rnHsTypeFVs doc pty @@ -243,25 +265,26 @@ rnExpr (ExprWithTySig expr pty) where doc = text "In an expression type signature" -rnExpr (HsIf p b1 b2) - = rnLExpr p `thenM` \ (p', fvP) -> - rnLExpr b1 `thenM` \ (b1', fvB1) -> - rnLExpr b2 `thenM` \ (b2', fvB2) -> - returnM (HsIf p' b1' b2', plusFVs [fvP, fvB1, fvB2]) +rnExpr (HsIf _ p b1 b2) + = do { (p', fvP) <- rnLExpr p + ; (b1', fvB1) <- rnLExpr b1 + ; (b2', fvB2) <- rnLExpr b2 + ; (mb_ite, fvITE) <- lookupIfThenElse + ; return (HsIf mb_ite p' b1' b2', plusFVs [fvITE, fvP, fvB1, fvB2]) } rnExpr (HsType a) = rnHsTypeFVs doc a `thenM` \ (t, fvT) -> - returnM (HsType t, fvT) + return (HsType t, fvT) where doc = text "In a type argument" rnExpr (ArithSeq _ seq) = rnArithSeq seq `thenM` \ (new_seq, fvs) -> - returnM (ArithSeq noPostTcExpr new_seq, fvs) + return (ArithSeq noPostTcExpr new_seq, fvs) rnExpr (PArrSeq _ seq) = rnArithSeq seq `thenM` \ (new_seq, fvs) -> - returnM (PArrSeq noPostTcExpr new_seq, fvs) + return (PArrSeq noPostTcExpr new_seq, fvs) \end{code} These three are pattern syntax appearing in expressions. @@ -271,6 +294,7 @@ We return a (bogus) EWildPat in each case. \begin{code} rnExpr e@EWildPat = patSynErr e rnExpr e@(EAsPat {}) = patSynErr e +rnExpr e@(EViewPat {}) = patSynErr e rnExpr e@(ELazyPat {}) = patSynErr e \end{code} @@ -283,14 +307,14 @@ rnExpr e@(ELazyPat {}) = patSynErr e \begin{code} rnExpr (HsProc pat body) = newArrowScope $ - rnPatsAndThen ProcExpr [pat] $ \ [pat'] -> + rnPat ProcExpr pat $ \ pat' -> rnCmdTop body `thenM` \ (body',fvBody) -> - returnM (HsProc pat' body', fvBody) + return (HsProc pat' body', fvBody) rnExpr (HsArrApp arrow arg _ ho rtl) = select_arrow_scope (rnLExpr arrow) `thenM` \ (arrow',fvArrow) -> rnLExpr arg `thenM` \ (arg',fvArg) -> - returnM (HsArrApp arrow' arg' placeHolderType ho rtl, + return (HsArrApp arrow' arg' placeHolderType ho rtl, fvArrow `plusFV` fvArg) where select_arrow_scope tc = case ho of @@ -300,7 +324,8 @@ rnExpr (HsArrApp arrow arg _ ho rtl) -- infix form rnExpr (HsArrForm op (Just _) [arg1, arg2]) = escapeArrowScope (rnLExpr op) - `thenM` \ (op'@(L _ (HsVar op_name)),fv_op) -> + `thenM` \ (op',fv_op) -> + let L _ (HsVar op_name) = op' in rnCmdTop arg1 `thenM` \ (arg1',fv_arg1) -> rnCmdTop arg2 `thenM` \ (arg2',fv_arg2) -> @@ -309,16 +334,52 @@ rnExpr (HsArrForm op (Just _) [arg1, arg2]) lookupFixityRn op_name `thenM` \ fixity -> mkOpFormRn arg1' op' fixity arg2' `thenM` \ final_e -> - returnM (final_e, + return (final_e, fv_arg1 `plusFV` fv_op `plusFV` fv_arg2) rnExpr (HsArrForm op fixity cmds) = escapeArrowScope (rnLExpr op) `thenM` \ (op',fvOp) -> rnCmdArgs cmds `thenM` \ (cmds',fvCmds) -> - returnM (HsArrForm op' fixity cmds', fvOp `plusFV` fvCmds) + return (HsArrForm op' fixity cmds', fvOp `plusFV` fvCmds) rnExpr other = pprPanic "rnExpr: unexpected expression" (ppr other) -- HsWrap + +---------------------- +-- See Note [Parsing sections] in Parser.y.pp +rnSection :: HsExpr RdrName -> RnM (HsExpr Name, FreeVars) +rnSection section@(SectionR op expr) + = do { (op', fvs_op) <- rnLExpr op + ; (expr', fvs_expr) <- rnLExpr expr + ; checkSectionPrec InfixR section op' expr' + ; return (SectionR op' expr', fvs_op `plusFV` fvs_expr) } + +rnSection section@(SectionL expr op) + = do { (expr', fvs_expr) <- rnLExpr expr + ; (op', fvs_op) <- rnLExpr op + ; checkSectionPrec InfixL section op' expr' + ; return (SectionL expr' op', fvs_op `plusFV` fvs_expr) } + +rnSection other = pprPanic "rnSection" (ppr other) +\end{code} + +%************************************************************************ +%* * + Records +%* * +%************************************************************************ + +\begin{code} +rnHsRecBinds :: HsRecFieldContext -> HsRecordBinds RdrName + -> RnM (HsRecordBinds Name, FreeVars) +rnHsRecBinds ctxt rec_binds@(HsRecFields { rec_dotdot = dd }) + = do { (flds, fvs) <- rnHsRecFields1 ctxt HsVar rec_binds + ; (flds', fvss) <- mapAndUnzipM rn_field flds + ; return (HsRecFields { rec_flds = flds', rec_dotdot = dd }, + fvs `plusFV` plusFVs fvss) } + where + rn_field fld = do { (arg', fvs) <- rnLExpr (hsRecFieldArg fld) + ; return (fld { hsRecFieldArg = arg' }, fvs) } \end{code} @@ -329,13 +390,14 @@ rnExpr other = pprPanic "rnExpr: unexpected expression" (ppr other) %************************************************************************ \begin{code} -rnCmdArgs [] = returnM ([], emptyFVs) +rnCmdArgs :: [LHsCmdTop RdrName] -> RnM ([LHsCmdTop Name], FreeVars) +rnCmdArgs [] = return ([], emptyFVs) rnCmdArgs (arg:args) = rnCmdTop arg `thenM` \ (arg',fvArg) -> rnCmdArgs args `thenM` \ (args',fvArgs) -> - returnM (arg':args', fvArg `plusFV` fvArgs) - + return (arg':args', fvArg `plusFV` fvArgs) +rnCmdTop :: LHsCmdTop RdrName -> RnM (LHsCmdTop Name, FreeVars) rnCmdTop = wrapLocFstM rnCmdTop' where rnCmdTop' (HsCmdTop cmd _ _ _) @@ -347,7 +409,7 @@ rnCmdTop = wrapLocFstM rnCmdTop' -- Generate the rebindable syntax for the monad lookupSyntaxTable cmd_names `thenM` \ (cmd_names', cmd_fvs) -> - returnM (HsCmdTop cmd' [] placeHolderType cmd_names', + return (HsCmdTop cmd' [] placeHolderType cmd_names', fvCmd `plusFV` cmd_fvs) --------------------------------------------------- @@ -369,41 +431,43 @@ convertOpFormsCmd (OpApp c1 op fixity c2) convertOpFormsCmd (HsPar c) = HsPar (convertOpFormsLCmd c) --- gaw 2004 convertOpFormsCmd (HsCase exp matches) = HsCase exp (convertOpFormsMatch matches) -convertOpFormsCmd (HsIf exp c1 c2) - = HsIf exp (convertOpFormsLCmd c1) (convertOpFormsLCmd c2) +convertOpFormsCmd (HsIf f exp c1 c2) + = HsIf f exp (convertOpFormsLCmd c1) (convertOpFormsLCmd c2) convertOpFormsCmd (HsLet binds cmd) = HsLet binds (convertOpFormsLCmd cmd) -convertOpFormsCmd (HsDo ctxt stmts body ty) - = HsDo ctxt (map (fmap convertOpFormsStmt) stmts) - (convertOpFormsLCmd body) ty +convertOpFormsCmd (HsDo ctxt stmts ty) + = HsDo ctxt (map (fmap convertOpFormsStmt) stmts) ty -- Anything else is unchanged. This includes HsArrForm (already done), -- things with no sub-commands, and illegal commands (which will be -- caught by the type checker) convertOpFormsCmd c = c +convertOpFormsStmt :: StmtLR id id -> StmtLR id id convertOpFormsStmt (BindStmt pat cmd _ _) = BindStmt pat (convertOpFormsLCmd cmd) noSyntaxExpr noSyntaxExpr -convertOpFormsStmt (ExprStmt cmd _ _) - = ExprStmt (convertOpFormsLCmd cmd) noSyntaxExpr placeHolderType -convertOpFormsStmt (RecStmt stmts lvs rvs es binds) - = RecStmt (map (fmap convertOpFormsStmt) stmts) lvs rvs es binds +convertOpFormsStmt (ExprStmt cmd _ _ _) + = ExprStmt (convertOpFormsLCmd cmd) noSyntaxExpr noSyntaxExpr placeHolderType +convertOpFormsStmt stmt@(RecStmt { recS_stmts = stmts }) + = stmt { recS_stmts = map (fmap convertOpFormsStmt) stmts } convertOpFormsStmt stmt = stmt +convertOpFormsMatch :: MatchGroup id -> MatchGroup id convertOpFormsMatch (MatchGroup ms ty) = MatchGroup (map (fmap convert) ms) ty where convert (Match pat mty grhss) = Match pat mty (convertOpFormsGRHSs grhss) +convertOpFormsGRHSs :: GRHSs id -> GRHSs id convertOpFormsGRHSs (GRHSs grhss binds) = GRHSs (map convertOpFormsGRHS grhss) binds +convertOpFormsGRHS :: Located (GRHS id) -> Located (GRHS id) convertOpFormsGRHS = fmap convert where convert (GRHS stmts cmd) = GRHS stmts (convertOpFormsLCmd cmd) @@ -418,60 +482,65 @@ methodNamesLCmd = methodNamesCmd . unLoc methodNamesCmd :: HsCmd Name -> CmdNeeds -methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsFirstOrderApp _rtl) +methodNamesCmd (HsArrApp _arrow _arg _ HsFirstOrderApp _rtl) = emptyFVs -methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsHigherOrderApp _rtl) +methodNamesCmd (HsArrApp _arrow _arg _ HsHigherOrderApp _rtl) = unitFV appAName -methodNamesCmd cmd@(HsArrForm {}) = emptyFVs +methodNamesCmd (HsArrForm {}) = emptyFVs methodNamesCmd (HsPar c) = methodNamesLCmd c -methodNamesCmd (HsIf p c1 c2) +methodNamesCmd (HsIf _ _ c1 c2) = methodNamesLCmd c1 `plusFV` methodNamesLCmd c2 `addOneFV` choiceAName -methodNamesCmd (HsLet b c) = methodNamesLCmd c +methodNamesCmd (HsLet _ c) = methodNamesLCmd c +methodNamesCmd (HsDo _ stmts _) = methodNamesStmts stmts +methodNamesCmd (HsApp c _) = methodNamesLCmd c +methodNamesCmd (HsLam match) = methodNamesMatch match -methodNamesCmd (HsDo sc stmts body ty) - = methodNamesStmts stmts `plusFV` methodNamesLCmd body - -methodNamesCmd (HsApp c e) = methodNamesLCmd c - -methodNamesCmd (HsLam match) = methodNamesMatch match - -methodNamesCmd (HsCase scrut matches) +methodNamesCmd (HsCase _ matches) = methodNamesMatch matches `addOneFV` choiceAName -methodNamesCmd other = emptyFVs +methodNamesCmd _ = emptyFVs -- Other forms can't occur in commands, but it's not convenient -- to error here so we just do what's convenient. -- The type checker will complain later --------------------------------------------------- +methodNamesMatch :: MatchGroup Name -> FreeVars methodNamesMatch (MatchGroup ms _) = plusFVs (map do_one ms) where - do_one (L _ (Match pats sig_ty grhss)) = methodNamesGRHSs grhss + do_one (L _ (Match _ _ grhss)) = methodNamesGRHSs grhss ------------------------------------------------- -- gaw 2004 -methodNamesGRHSs (GRHSs grhss binds) = plusFVs (map methodNamesGRHS grhss) +methodNamesGRHSs :: GRHSs Name -> FreeVars +methodNamesGRHSs (GRHSs grhss _) = plusFVs (map methodNamesGRHS grhss) ------------------------------------------------- -methodNamesGRHS (L _ (GRHS stmts rhs)) = methodNamesLCmd rhs + +methodNamesGRHS :: Located (GRHS Name) -> CmdNeeds +methodNamesGRHS (L _ (GRHS _ rhs)) = methodNamesLCmd rhs --------------------------------------------------- +methodNamesStmts :: [Located (StmtLR Name Name)] -> FreeVars methodNamesStmts stmts = plusFVs (map methodNamesLStmt stmts) --------------------------------------------------- +methodNamesLStmt :: Located (StmtLR Name Name) -> FreeVars methodNamesLStmt = methodNamesStmt . unLoc -methodNamesStmt (ExprStmt cmd _ _) = methodNamesLCmd cmd -methodNamesStmt (BindStmt pat cmd _ _) = methodNamesLCmd cmd -methodNamesStmt (RecStmt stmts _ _ _ _) - = methodNamesStmts stmts `addOneFV` loopAName -methodNamesStmt (LetStmt b) = emptyFVs -methodNamesStmt (ParStmt ss) = emptyFVs - -- ParStmt can't occur in commands, but it's not convenient to error +methodNamesStmt :: StmtLR Name Name -> FreeVars +methodNamesStmt (LastStmt cmd _) = methodNamesLCmd cmd +methodNamesStmt (ExprStmt cmd _ _ _) = methodNamesLCmd cmd +methodNamesStmt (BindStmt _ cmd _ _) = methodNamesLCmd cmd +methodNamesStmt (RecStmt { recS_stmts = stmts }) = methodNamesStmts stmts `addOneFV` loopAName +methodNamesStmt (LetStmt _) = emptyFVs +methodNamesStmt (ParStmt _ _ _ _) = emptyFVs +methodNamesStmt (TransformStmt {}) = emptyFVs +methodNamesStmt (GroupStmt {}) = emptyFVs + -- ParStmt, TransformStmt and GroupStmt can't occur in commands, but it's not convenient to error -- here so we just do what's convenient \end{code} @@ -483,51 +552,29 @@ methodNamesStmt (ParStmt ss) = emptyFVs %************************************************************************ \begin{code} +rnArithSeq :: ArithSeqInfo RdrName -> RnM (ArithSeqInfo Name, FreeVars) rnArithSeq (From expr) = rnLExpr expr `thenM` \ (expr', fvExpr) -> - returnM (From expr', fvExpr) + return (From expr', fvExpr) rnArithSeq (FromThen expr1 expr2) = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) -> rnLExpr expr2 `thenM` \ (expr2', fvExpr2) -> - returnM (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2) + return (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2) rnArithSeq (FromTo expr1 expr2) = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) -> rnLExpr expr2 `thenM` \ (expr2', fvExpr2) -> - returnM (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2) + return (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2) rnArithSeq (FromThenTo expr1 expr2 expr3) = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) -> rnLExpr expr2 `thenM` \ (expr2', fvExpr2) -> rnLExpr expr3 `thenM` \ (expr3', fvExpr3) -> - returnM (FromThenTo expr1' expr2' expr3', + return (FromThenTo expr1' expr2' expr3', plusFVs [fvExpr1, fvExpr2, fvExpr3]) \end{code} - -%************************************************************************ -%* * -\subsubsection{@Rbinds@s and @Rpats@s: in record expressions} -%* * -%************************************************************************ - -\begin{code} -rnRbinds str rbinds - = mappM_ field_dup_err dup_fields `thenM_` - mapFvRn rn_rbind rbinds `thenM` \ (rbinds', fvRbind) -> - returnM (rbinds', fvRbind) - where - (_, dup_fields) = removeDups cmpLocated [ f | (f,_) <- rbinds ] - - field_dup_err dups = mappM_ (\f -> addLocErr f (dupFieldErr str)) dups - - rn_rbind (field, expr) - = lookupLocatedGlobalOccRn field `thenM` \ fieldname -> - rnLExpr expr `thenM` \ (expr', fvExpr) -> - returnM ((fieldname, expr'), fvExpr `addOneFV` unLoc fieldname) -\end{code} - %************************************************************************ %* * Template Haskell brackets @@ -535,58 +582,48 @@ rnRbinds str rbinds %************************************************************************ \begin{code} +rnBracket :: HsBracket RdrName -> RnM (HsBracket Name, FreeVars) rnBracket (VarBr n) = do { name <- lookupOccRn n ; this_mod <- getModule - ; checkM (nameIsLocalOrFrom this_mod name) $ -- Reason: deprecation checking asumes the - do { loadInterfaceForName msg name -- home interface is loaded, and this is the + ; unless (nameIsLocalOrFrom this_mod name) $ -- Reason: deprecation checking asumes the + do { _ <- loadInterfaceForName msg name -- home interface is loaded, and this is the ; return () } -- only way that is going to happen - ; returnM (VarBr name, unitFV name) } + ; return (VarBr name, unitFV name) } where - msg = ptext SLIT("Need interface for Template Haskell quoted Name") + msg = ptext (sLit "Need interface for Template Haskell quoted Name") rnBracket (ExpBr e) = do { (e', fvs) <- rnLExpr e ; return (ExpBr e', fvs) } -rnBracket (PatBr p) = do { (p', fvs) <- rnLPat p - ; return (PatBr p', fvs) } + +rnBracket (PatBr p) = rnPat ThPatQuote p $ \ p' -> return (PatBr p', emptyFVs) + rnBracket (TypBr t) = do { (t', fvs) <- rnHsTypeFVs doc t ; return (TypBr t', fvs) } where - doc = ptext SLIT("In a Template-Haskell quoted type") -rnBracket (DecBr group) - = do { gbl_env <- getGblEnv - - ; let gbl_env1 = gbl_env { tcg_mod = thFAKE } - -- Note the thFAKE. The top-level names from the bracketed - -- declarations will go into the name cache, and we don't want them to - -- confuse the Names for the current module. - -- By using a pretend module, thFAKE, we keep them safely out of the way. - - ; avails <- getLocalDeclBinders gbl_env1 group - ; let names = concatMap availNames avails - - ; let new_occs = map nameOccName names - trimmed_rdr_env = hideSomeUnquals (tcg_rdr_env gbl_env) new_occs - - ; rdr_env' <- extendRdrEnvRn trimmed_rdr_env avails - -- In this situation we want to *shadow* top-level bindings. - -- foo = 1 - -- bar = [d| foo = 1|] - -- If we don't shadow, we'll get an ambiguity complaint when we do - -- a lookupTopBndrRn (which uses lookupGreLocalRn) on the binder of the 'foo' - -- - -- Furthermore, arguably if the splice does define foo, that should hide - -- any foo's further out - -- - -- The shadowing is acheived by the call to hideSomeUnquals, which removes - -- the unqualified bindings of things defined by the bracket - - ; setGblEnv (gbl_env { tcg_rdr_env = rdr_env', - tcg_dus = emptyDUs }) $ do - -- The emptyDUs is so that we just collect uses for this group alone - - { (tcg_env, group') <- rnSrcDecls group - -- Discard the tcg_env; it contains only extra info about fixity - ; return (DecBr group', allUses (tcg_dus tcg_env)) } } + doc = ptext (sLit "In a Template-Haskell quoted type") + +rnBracket (DecBrL decls) + = do { (group, mb_splice) <- findSplice decls + ; case mb_splice of + Nothing -> return () + Just (SpliceDecl (L loc _) _, _) + -> setSrcSpan loc $ + addErr (ptext (sLit "Declaration splices are not permitted inside declaration brackets")) + -- Why not? See Section 7.3 of the TH paper. + + ; gbl_env <- getGblEnv + ; let new_gbl_env = gbl_env { tcg_dus = emptyDUs } + -- The emptyDUs is so that we just collect uses for this + -- group alone in the call to rnSrcDecls below + ; (tcg_env, group') <- setGblEnv new_gbl_env $ + setStage thRnBrack $ + rnSrcDecls group + + -- Discard the tcg_env; it contains only extra info about fixity + ; traceRn (text "rnBracket dec" <+> (ppr (tcg_dus tcg_env) $$ ppr (duUses (tcg_dus tcg_env)))) + ; return (DecBrG group', duUses (tcg_dus tcg_env)) } + +rnBracket (DecBrG _) = panic "rnBracket: unexpected DecBrG" \end{code} %************************************************************************ @@ -596,134 +633,259 @@ rnBracket (DecBr group) %************************************************************************ \begin{code} -rnStmts :: HsStmtContext Name -> [LStmt RdrName] - -> RnM (thing, FreeVars) - -> RnM (([LStmt Name], thing), FreeVars) - -rnStmts (MDoExpr _) = rnMDoStmts -rnStmts ctxt = rnNormalStmts ctxt - -rnNormalStmts :: HsStmtContext Name -> [LStmt RdrName] - -> RnM (thing, FreeVars) - -> RnM (([LStmt Name], thing), FreeVars) --- Used for cases *other* than recursive mdo --- Implements nested scopes - -rnNormalStmts ctxt [] thing_inside - = do { (thing, fvs) <- thing_inside - ; return (([],thing), fvs) } - -rnNormalStmts ctxt (L loc stmt : stmts) thing_inside - = do { ((stmt', (stmts', thing)), fvs) - <- rnStmt ctxt stmt $ - rnNormalStmts ctxt stmts thing_inside - ; return (((L loc stmt' : stmts'), thing), fvs) } - -rnStmt :: HsStmtContext Name -> Stmt RdrName - -> RnM (thing, FreeVars) - -> RnM ((Stmt Name, thing), FreeVars) +rnStmts :: HsStmtContext Name -> [LStmt RdrName] + -> ([Name] -> RnM (thing, FreeVars)) + -> RnM (([LStmt Name], thing), FreeVars) +-- Variables bound by the Stmts, and mentioned in thing_inside, +-- do not appear in the result FreeVars + +rnStmts ctxt [] thing_inside + = do { checkEmptyStmts ctxt + ; (thing, fvs) <- thing_inside [] + ; return (([], thing), fvs) } + +rnStmts MDoExpr stmts thing_inside -- Deal with mdo + = -- Behave like do { rec { ...all but last... }; last } + do { ((stmts1, (stmts2, thing)), fvs) + <- rnStmt MDoExpr (noLoc $ mkRecStmt all_but_last) $ \ _ -> + do { last_stmt' <- checkLastStmt MDoExpr last_stmt + ; rnStmt MDoExpr last_stmt' thing_inside } + ; return (((stmts1 ++ stmts2), thing), fvs) } + where + Just (all_but_last, last_stmt) = snocView stmts + +rnStmts ctxt (lstmt@(L loc _) : lstmts) thing_inside + | null lstmts + = setSrcSpan loc $ + do { lstmt' <- checkLastStmt ctxt lstmt + ; rnStmt ctxt lstmt' thing_inside } + + | otherwise + = do { ((stmts1, (stmts2, thing)), fvs) + <- setSrcSpan loc $ + do { checkStmt ctxt lstmt + ; rnStmt ctxt lstmt $ \ bndrs1 -> + rnStmts ctxt lstmts $ \ bndrs2 -> + thing_inside (bndrs1 ++ bndrs2) } + ; return (((stmts1 ++ stmts2), thing), fvs) } + +---------------------- +rnStmt :: HsStmtContext Name + -> LStmt RdrName + -> ([Name] -> RnM (thing, FreeVars)) + -> RnM (([LStmt Name], thing), FreeVars) +-- Variables bound by the Stmt, and mentioned in thing_inside, +-- do not appear in the result FreeVars + +rnStmt _ (L loc (LastStmt expr _)) thing_inside + = do { (expr', fv_expr) <- rnLExpr expr + ; (ret_op, fvs1) <- lookupSyntaxName returnMName + ; (thing, fvs3) <- thing_inside [] + ; return (([L loc (LastStmt expr' ret_op)], thing), + fv_expr `plusFV` fvs1 `plusFV` fvs3) } -rnStmt ctxt (ExprStmt expr _ _) thing_inside +rnStmt ctxt (L loc (ExprStmt expr _ _ _)) thing_inside = do { (expr', fv_expr) <- rnLExpr expr ; (then_op, fvs1) <- lookupSyntaxName thenMName - ; (thing, fvs2) <- thing_inside - ; return ((ExprStmt expr' then_op placeHolderType, thing), - fv_expr `plusFV` fvs1 `plusFV` fvs2) } - -rnStmt ctxt (BindStmt pat expr _ _) thing_inside + ; (guard_op, fvs2) <- if isMonadCompExpr ctxt + then lookupSyntaxName guardMName + else return (noSyntaxExpr, emptyFVs) + ; (thing, fvs3) <- thing_inside [] + ; return (([L loc (ExprStmt expr' then_op guard_op placeHolderType)], thing), + fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) } + +rnStmt ctxt (L loc (BindStmt pat expr _ _)) thing_inside = do { (expr', fv_expr) <- rnLExpr expr -- The binders do not scope over the expression ; (bind_op, fvs1) <- lookupSyntaxName bindMName ; (fail_op, fvs2) <- lookupSyntaxName failMName - ; rnPatsAndThen (StmtCtxt ctxt) [pat] $ \ [pat'] -> do - { (thing, fvs3) <- thing_inside - ; return ((BindStmt pat' expr' bind_op fail_op, thing), + ; rnPat (StmtCtxt ctxt) pat $ \ pat' -> do + { (thing, fvs3) <- thing_inside (collectPatBinders pat') + ; return (([L loc (BindStmt pat' expr' bind_op fail_op)], thing), fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) }} - -- fv_expr shouldn't really be filtered by the rnPatsAndThen + -- fv_expr shouldn't really be filtered by the rnPatsAndThen -- but it does not matter because the names are unique -rnStmt ctxt (LetStmt binds) thing_inside - = do { checkErr (ok ctxt binds) - (badIpBinds (ptext SLIT("a parallel list comprehension:")) binds) - ; rnLocalBindsAndThen binds $ \ binds' -> do - { (thing, fvs) <- thing_inside - ; return ((LetStmt binds', thing), fvs) }} - where - -- We do not allow implicit-parameter bindings in a parallel - -- list comprehension. I'm not sure what it might mean. - ok (ParStmtCtxt _) (HsIPBinds _) = False - ok _ _ = True - -rnStmt ctxt (RecStmt rec_stmts _ _ _ _) thing_inside - = bindLocatedLocalsRn doc (collectLStmtsBinders rec_stmts) $ \ bndrs -> - rn_rec_stmts bndrs rec_stmts `thenM` \ segs -> - thing_inside `thenM` \ (thing, fvs) -> - let - segs_w_fwd_refs = addFwdRefs segs - (ds, us, fs, rec_stmts') = unzip4 segs_w_fwd_refs - later_vars = nameSetToList (plusFVs ds `intersectNameSet` fvs) - fwd_vars = nameSetToList (plusFVs fs) - uses = plusFVs us - rec_stmt = RecStmt rec_stmts' later_vars fwd_vars [] emptyLHsBinds - in - returnM ((rec_stmt, thing), uses `plusFV` fvs) - where - doc = text "In a recursive do statement" - -rnStmt ctxt (ParStmt segs) thing_inside - = do { opt_GlasgowExts <- doptM Opt_GlasgowExts - ; checkM opt_GlasgowExts parStmtErr - ; orig_lcl_env <- getLocalRdrEnv - ; ((segs',thing), fvs) <- go orig_lcl_env [] segs - ; return ((ParStmt segs', thing), fvs) } +rnStmt _ (L loc (LetStmt binds)) thing_inside + = do { rnLocalBindsAndThen binds $ \binds' -> do + { (thing, fvs) <- thing_inside (collectLocalBinders binds') + ; return (([L loc (LetStmt binds')], thing), fvs) } } + +rnStmt _ (L _ (RecStmt { recS_stmts = rec_stmts })) thing_inside + = do { + -- Step1: Bring all the binders of the mdo into scope + -- (Remember that this also removes the binders from the + -- finally-returned free-vars.) + -- And rename each individual stmt, making a + -- singleton segment. At this stage the FwdRefs field + -- isn't finished: it's empty for all except a BindStmt + -- for which it's the fwd refs within the bind itself + -- (This set may not be empty, because we're in a recursive + -- context.) + ; rnRecStmtsAndThen rec_stmts $ \ segs -> do + + { let bndrs = nameSetToList $ foldr (unionNameSets . (\(ds,_,_,_) -> ds)) + emptyNameSet segs + ; (thing, fvs_later) <- thing_inside bndrs + ; (return_op, fvs1) <- lookupSyntaxName returnMName + ; (mfix_op, fvs2) <- lookupSyntaxName mfixName + ; (bind_op, fvs3) <- lookupSyntaxName bindMName + ; let + -- Step 2: Fill in the fwd refs. + -- The segments are all singletons, but their fwd-ref + -- field mentions all the things used by the segment + -- that are bound after their use + segs_w_fwd_refs = addFwdRefs segs + + -- Step 3: Group together the segments to make bigger segments + -- Invariant: in the result, no segment uses a variable + -- bound in a later segment + grouped_segs = glomSegments segs_w_fwd_refs + + -- Step 4: Turn the segments into Stmts + -- Use RecStmt when and only when there are fwd refs + -- Also gather up the uses from the end towards the + -- start, so we can tell the RecStmt which things are + -- used 'after' the RecStmt + empty_rec_stmt = emptyRecStmt { recS_ret_fn = return_op + , recS_mfix_fn = mfix_op + , recS_bind_fn = bind_op } + (rec_stmts', fvs) = segsToStmts empty_rec_stmt grouped_segs fvs_later + + ; return ((rec_stmts', thing), fvs `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) } } + +rnStmt ctxt (L loc (ParStmt segs _ _ _)) thing_inside + = do { ((mzip_op, fvs1), (bind_op, fvs2), (return_op, fvs3)) <- if isMonadCompExpr ctxt + then (,,) <$> lookupSyntaxName mzipName + <*> lookupSyntaxName bindMName + <*> lookupSyntaxName returnMName + else return ( (noSyntaxExpr, emptyFVs) + , (noSyntaxExpr, emptyFVs) + , (noSyntaxExpr, emptyFVs) ) + ; ((segs', thing), fvs4) <- rnParallelStmts (ParStmtCtxt ctxt) segs thing_inside + ; return ( ([L loc (ParStmt segs' mzip_op bind_op return_op)], thing) + , fvs1 `plusFV` fvs2 `plusFV` fvs3 `plusFV` fvs4) } + +rnStmt ctxt (L loc (TransformStmt stmts _ using by _ _)) thing_inside + = do { (using', fvs1) <- rnLExpr using + + ; ((stmts', (by', used_bndrs, thing)), fvs2) + <- rnStmts (TransformStmtCtxt ctxt) stmts $ \ bndrs -> + do { (by', fvs_by) <- case by of + Nothing -> return (Nothing, emptyFVs) + Just e -> do { (e', fvs) <- rnLExpr e; return (Just e', fvs) } + ; (thing, fvs_thing) <- thing_inside bndrs + ; let fvs = fvs_by `plusFV` fvs_thing + used_bndrs = filter (`elemNameSet` fvs) bndrs + -- The paper (Fig 5) has a bug here; we must treat any free varaible of + -- the "thing inside", **or of the by-expression**, as used + ; return ((by', used_bndrs, thing), fvs) } + + -- Lookup `(>>=)` and `fail` for monad comprehensions + ; ((return_op, fvs3), (bind_op, fvs4)) <- + if isMonadCompExpr ctxt + then (,) <$> lookupSyntaxName returnMName + <*> lookupSyntaxName bindMName + else return ( (noSyntaxExpr, emptyFVs) + , (noSyntaxExpr, emptyFVs) ) + + ; return (([L loc (TransformStmt stmts' used_bndrs using' by' return_op bind_op)], thing), + fvs1 `plusFV` fvs2 `plusFV` fvs3 `plusFV` fvs4) } + +rnStmt ctxt (L loc (GroupStmt { grpS_stmts = stmts, grpS_by = by, grpS_explicit = explicit + , grpS_using = using })) thing_inside + = do { -- Rename the 'using' expression in the context before the transform is begun + let implicit_name | isMonadCompExpr ctxt = groupMName + | otherwise = groupWithName + ; (using', fvs1) <- if explicit + then rnLExpr using + else do { (e,fvs) <- lookupSyntaxName implicit_name + ; return (noLoc e, fvs) } + + -- Rename the stmts and the 'by' expression + -- Keep track of the variables mentioned in the 'by' expression + ; ((stmts', (by', used_bndrs, thing)), fvs2) + <- rnStmts (TransformStmtCtxt ctxt) stmts $ \ bndrs -> + do { (by', fvs_by) <- mapMaybeFvRn rnLExpr by + ; (thing, fvs_thing) <- thing_inside bndrs + ; let fvs = fvs_by `plusFV` fvs_thing + used_bndrs = filter (`elemNameSet` fvs) bndrs + ; return ((by', used_bndrs, thing), fvs) } + + -- Lookup `return`, `(>>=)` and `liftM` for monad comprehensions + ; ((return_op, fvs3), (bind_op, fvs4), (fmap_op, fvs5)) <- + if isMonadCompExpr ctxt + then (,,) <$> lookupSyntaxName returnMName + <*> lookupSyntaxName bindMName + <*> lookupSyntaxName fmapName + else return ( (noSyntaxExpr, emptyFVs) + , (noSyntaxExpr, emptyFVs) + , (noSyntaxExpr, emptyFVs) ) + + ; let all_fvs = fvs1 `plusFV` fvs2 `plusFV` fvs3 `plusFV` fvs4 + `plusFV` fvs5 + bndr_map = used_bndrs `zip` used_bndrs + -- See Note [GroupStmt binder map] in HsExpr + + ; traceRn (text "rnStmt: implicitly rebound these used binders:" <+> ppr bndr_map) + ; return (([L loc (GroupStmt { grpS_stmts = stmts', grpS_bndrs = bndr_map + , grpS_by = by', grpS_using = using', grpS_explicit = explicit + , grpS_ret = return_op, grpS_bind = bind_op + , grpS_fmap = fmap_op })], thing), all_fvs) } + +type ParSeg id = ([LStmt id], [id]) -- The Names are bound by the Stmts + +rnParallelStmts :: forall thing. HsStmtContext Name + -> [ParSeg RdrName] + -> ([Name] -> RnM (thing, FreeVars)) + -> RnM (([ParSeg Name], thing), FreeVars) +-- Note [Renaming parallel Stmts] +rnParallelStmts ctxt segs thing_inside + = do { orig_lcl_env <- getLocalRdrEnv + ; rn_segs orig_lcl_env [] segs } where --- type ParSeg id = [([LStmt id], [id])] --- go :: NameSet -> [ParSeg RdrName] --- -> RnM (([ParSeg Name], thing), FreeVars) - - go orig_lcl_env bndrs [] - = do { let { (bndrs', dups) = removeDups cmpByOcc bndrs - ; inner_env = extendLocalRdrEnv orig_lcl_env bndrs' } - ; mappM dupErr dups - ; (thing, fvs) <- setLocalRdrEnv inner_env thing_inside - ; return (([], thing), fvs) } - - go orig_lcl_env bndrs_so_far ((stmts, _) : segs) - = do { ((stmts', (bndrs, segs', thing)), fvs) - <- rnNormalStmts par_ctxt stmts $ do - { -- Find the Names that are bound by stmts - lcl_env <- getLocalRdrEnv - ; let { rdr_bndrs = collectLStmtsBinders stmts - ; bndrs = map ( expectJust "rnStmt" - . lookupLocalRdrEnv lcl_env - . unLoc) rdr_bndrs - ; new_bndrs = nub bndrs ++ bndrs_so_far - -- The nub is because there might be shadowing - -- x <- e1; x <- e2 - -- So we'll look up (Unqual x) twice, getting - -- the second binding both times, which is the - } -- one we want - - -- Typecheck the thing inside, passing on all - -- the Names bound, but separately; revert the envt - ; ((segs', thing), fvs) <- setLocalRdrEnv orig_lcl_env $ - go orig_lcl_env new_bndrs segs - - -- Figure out which of the bound names are used - ; let used_bndrs = filter (`elemNameSet` fvs) bndrs - ; return ((used_bndrs, segs', thing), fvs) } - - ; let seg' = (stmts', bndrs) - ; return (((seg':segs'), thing), - delListFromNameSet fvs bndrs) } - - par_ctxt = ParStmtCtxt ctxt + rn_segs :: LocalRdrEnv + -> [Name] -> [ParSeg RdrName] + -> RnM (([ParSeg Name], thing), FreeVars) + rn_segs _ bndrs_so_far [] + = do { let (bndrs', dups) = removeDups cmpByOcc bndrs_so_far + ; mapM_ dupErr dups + ; (thing, fvs) <- bindLocalNames bndrs' (thing_inside bndrs') + ; return (([], thing), fvs) } + + rn_segs env bndrs_so_far ((stmts,_) : segs) + = do { ((stmts', (used_bndrs, segs', thing)), fvs) + <- rnStmts ctxt stmts $ \ bndrs -> + setLocalRdrEnv env $ do + { ((segs', thing), fvs) <- rn_segs env (bndrs ++ bndrs_so_far) segs + ; let used_bndrs = filter (`elemNameSet` fvs) bndrs + ; return ((used_bndrs, segs', thing), fvs) } + + ; let seg' = (stmts', used_bndrs) + ; return ((seg':segs', thing), fvs) } cmpByOcc n1 n2 = nameOccName n1 `compare` nameOccName n2 - dupErr vs = addErr (ptext SLIT("Duplicate binding in parallel list comprehension for:") - <+> quotes (ppr (head vs))) + dupErr vs = addErr (ptext (sLit "Duplicate binding in parallel list comprehension for:") + <+> quotes (ppr (head vs))) \end{code} +Note [Renaming parallel Stmts] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Renaming parallel statements is painful. Given, say + [ a+c | a <- as, bs <- bss + | c <- bs, a <- ds ] +Note that + (a) In order to report "Defined by not used" about 'bs', we must rename + each group of Stmts with a thing_inside whose FreeVars include at least {a,c} + + (b) We want to report that 'a' is illegally bound in both branches + + (c) The 'bs' in the second group must obviously not be captured by + the binding in the first group + +To satisfy (a) we nest the segements. +To satisfy (b) we check for duplicates just before thing_inside. +To satisfy (c) we reset the LocalRdrEnv each time. %************************************************************************ %* * @@ -741,92 +903,161 @@ type Segment stmts = (Defs, stmts) -- Either Stmt or [Stmt] ----------------------------------------------------- -rnMDoStmts :: [LStmt RdrName] - -> RnM (thing, FreeVars) - -> RnM (([LStmt Name], thing), FreeVars) -rnMDoStmts stmts thing_inside - = -- Step1: bring all the binders of the mdo into scope - -- Remember that this also removes the binders from the - -- finally-returned free-vars - bindLocatedLocalsRn doc (collectLStmtsBinders stmts) $ \ bndrs -> - do { - -- Step 2: Rename each individual stmt, making a - -- singleton segment. At this stage the FwdRefs field - -- isn't finished: it's empty for all except a BindStmt - -- for which it's the fwd refs within the bind itself - -- (This set may not be empty, because we're in a recursive - -- context.) - segs <- rn_rec_stmts bndrs stmts - - ; (thing, fvs_later) <- thing_inside +-- wrapper that does both the left- and right-hand sides +rnRecStmtsAndThen :: [LStmt RdrName] + -- assumes that the FreeVars returned includes + -- the FreeVars of the Segments + -> ([Segment (LStmt Name)] -> RnM (a, FreeVars)) + -> RnM (a, FreeVars) +rnRecStmtsAndThen s cont + = do { -- (A) Make the mini fixity env for all of the stmts + fix_env <- makeMiniFixityEnv (collectRecStmtsFixities s) + + -- (B) Do the LHSes + ; new_lhs_and_fv <- rn_rec_stmts_lhs fix_env s + + -- ...bring them and their fixities into scope + ; let bound_names = collectLStmtsBinders (map fst new_lhs_and_fv) + -- Fake uses of variables introduced implicitly (warning suppression, see #4404) + implicit_uses = lStmtsImplicits (map fst new_lhs_and_fv) + ; bindLocalNamesFV bound_names $ + addLocalFixities fix_env bound_names $ do + + -- (C) do the right-hand-sides and thing-inside + { segs <- rn_rec_stmts bound_names new_lhs_and_fv + ; (res, fvs) <- cont segs + ; warnUnusedLocalBinds bound_names (fvs `unionNameSets` implicit_uses) + ; return (res, fvs) }} + +-- get all the fixity decls in any Let stmt +collectRecStmtsFixities :: [LStmtLR RdrName RdrName] -> [LFixitySig RdrName] +collectRecStmtsFixities l = + foldr (\ s -> \acc -> case s of + (L _ (LetStmt (HsValBinds (ValBindsIn _ sigs)))) -> + foldr (\ sig -> \ acc -> case sig of + (L loc (FixSig s)) -> (L loc s) : acc + _ -> acc) acc sigs + _ -> acc) [] l + +-- left-hand sides + +rn_rec_stmt_lhs :: MiniFixityEnv + -> LStmt RdrName + -- rename LHS, and return its FVs + -- Warning: we will only need the FreeVars below in the case of a BindStmt, + -- so we don't bother to compute it accurately in the other cases + -> RnM [(LStmtLR Name RdrName, FreeVars)] + +rn_rec_stmt_lhs _ (L loc (ExprStmt expr a b c)) + = return [(L loc (ExprStmt expr a b c), emptyFVs)] + +rn_rec_stmt_lhs _ (L loc (LastStmt expr a)) + = return [(L loc (LastStmt expr a), emptyFVs)] + +rn_rec_stmt_lhs fix_env (L loc (BindStmt pat expr a b)) + = do + -- should the ctxt be MDo instead? + (pat', fv_pat) <- rnBindPat (localRecNameMaker fix_env) pat + return [(L loc (BindStmt pat' expr a b), + fv_pat)] + +rn_rec_stmt_lhs _ (L _ (LetStmt binds@(HsIPBinds _))) + = failWith (badIpBinds (ptext (sLit "an mdo expression")) binds) + +rn_rec_stmt_lhs fix_env (L loc (LetStmt (HsValBinds binds))) + = do (_bound_names, binds') <- rnLocalValBindsLHS fix_env binds + return [(L loc (LetStmt (HsValBinds binds')), + -- Warning: this is bogus; see function invariant + emptyFVs + )] + +-- XXX Do we need to do something with the return and mfix names? +rn_rec_stmt_lhs fix_env (L _ (RecStmt { recS_stmts = stmts })) -- Flatten Rec inside Rec + = rn_rec_stmts_lhs fix_env stmts + +rn_rec_stmt_lhs _ stmt@(L _ (ParStmt _ _ _ _)) -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt" (ppr stmt) + +rn_rec_stmt_lhs _ stmt@(L _ (TransformStmt {})) -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt" (ppr stmt) + +rn_rec_stmt_lhs _ stmt@(L _ (GroupStmt {})) -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt" (ppr stmt) - ; let - -- Step 3: Fill in the fwd refs. - -- The segments are all singletons, but their fwd-ref - -- field mentions all the things used by the segment - -- that are bound after their use - segs_w_fwd_refs = addFwdRefs segs - - -- Step 4: Group together the segments to make bigger segments - -- Invariant: in the result, no segment uses a variable - -- bound in a later segment - grouped_segs = glomSegments segs_w_fwd_refs +rn_rec_stmt_lhs _ (L _ (LetStmt EmptyLocalBinds)) + = panic "rn_rec_stmt LetStmt EmptyLocalBinds" - -- Step 5: Turn the segments into Stmts - -- Use RecStmt when and only when there are fwd refs - -- Also gather up the uses from the end towards the - -- start, so we can tell the RecStmt which things are - -- used 'after' the RecStmt - (stmts', fvs) = segsToStmts grouped_segs fvs_later +rn_rec_stmts_lhs :: MiniFixityEnv + -> [LStmt RdrName] + -> RnM [(LStmtLR Name RdrName, FreeVars)] +rn_rec_stmts_lhs fix_env stmts + = do { ls <- concatMapM (rn_rec_stmt_lhs fix_env) stmts + ; let boundNames = collectLStmtsBinders (map fst ls) + -- First do error checking: we need to check for dups here because we + -- don't bind all of the variables from the Stmt at once + -- with bindLocatedLocals. + ; checkDupNames boundNames + ; return ls } - ; return ((stmts', thing), fvs) } - where - doc = text "In a recursive mdo-expression" ---------------------------------------------- -rn_rec_stmts :: [Name] -> [LStmt RdrName] -> RnM [Segment (LStmt Name)] -rn_rec_stmts bndrs stmts = mappM (rn_rec_stmt bndrs) stmts `thenM` \ segs_s -> - returnM (concat segs_s) +-- right-hand-sides ----------------------------------------------------- -rn_rec_stmt :: [Name] -> LStmt RdrName -> RnM [Segment (LStmt Name)] +rn_rec_stmt :: [Name] -> LStmtLR Name RdrName -> FreeVars -> RnM [Segment (LStmt Name)] -- Rename a Stmt that is inside a RecStmt (or mdo) -- Assumes all binders are already in scope -- Turns each stmt into a singleton Stmt +rn_rec_stmt _ (L loc (LastStmt expr _)) _ + = do { (expr', fv_expr) <- rnLExpr expr + ; (ret_op, fvs1) <- lookupSyntaxName returnMName + ; return [(emptyNameSet, fv_expr `plusFV` fvs1, emptyNameSet, + L loc (LastStmt expr' ret_op))] } -rn_rec_stmt all_bndrs (L loc (ExprStmt expr _ _)) - = rnLExpr expr `thenM` \ (expr', fvs) -> +rn_rec_stmt _ (L loc (ExprStmt expr _ _ _)) _ + = rnLExpr expr `thenM` \ (expr', fvs) -> lookupSyntaxName thenMName `thenM` \ (then_op, fvs1) -> - returnM [(emptyNameSet, fvs `plusFV` fvs1, emptyNameSet, - L loc (ExprStmt expr' then_op placeHolderType))] + return [(emptyNameSet, fvs `plusFV` fvs1, emptyNameSet, + L loc (ExprStmt expr' then_op noSyntaxExpr placeHolderType))] -rn_rec_stmt all_bndrs (L loc (BindStmt pat expr _ _)) +rn_rec_stmt _ (L loc (BindStmt pat' expr _ _)) fv_pat = rnLExpr expr `thenM` \ (expr', fv_expr) -> - rnLPat pat `thenM` \ (pat', fv_pat) -> lookupSyntaxName bindMName `thenM` \ (bind_op, fvs1) -> lookupSyntaxName failMName `thenM` \ (fail_op, fvs2) -> let bndrs = mkNameSet (collectPatBinders pat') fvs = fv_expr `plusFV` fv_pat `plusFV` fvs1 `plusFV` fvs2 in - returnM [(bndrs, fvs, bndrs `intersectNameSet` fvs, + return [(bndrs, fvs, bndrs `intersectNameSet` fvs, L loc (BindStmt pat' expr' bind_op fail_op))] -rn_rec_stmt all_bndrs (L loc (LetStmt binds@(HsIPBinds _))) - = do { addErr (badIpBinds (ptext SLIT("an mdo expression")) binds) - ; failM } +rn_rec_stmt _ (L _ (LetStmt binds@(HsIPBinds _))) _ + = failWith (badIpBinds (ptext (sLit "an mdo expression")) binds) -rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds))) - = rnValBinds (trimWith all_bndrs) binds `thenM` \ (binds', du_binds) -> - returnM [(duDefs du_binds, duUses du_binds, - emptyNameSet, L loc (LetStmt (HsValBinds binds')))] +rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds'))) _ = do + (binds', du_binds) <- + -- fixities and unused are handled above in rnRecStmtsAndThen + rnLocalValBindsRHS (mkNameSet all_bndrs) binds' + return [(duDefs du_binds, allUses du_binds, + emptyNameSet, L loc (LetStmt (HsValBinds binds')))] -rn_rec_stmt all_bndrs (L loc (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec - = rn_rec_stmts all_bndrs stmts +-- no RecStmt case becuase they get flattened above when doing the LHSes +rn_rec_stmt _ stmt@(L _ (RecStmt {})) _ + = pprPanic "rn_rec_stmt: RecStmt" (ppr stmt) -rn_rec_stmt all_bndrs stmt@(L _ (ParStmt _)) -- Syntactically illegal in mdo - = pprPanic "rn_rec_stmt" (ppr stmt) +rn_rec_stmt _ stmt@(L _ (ParStmt {})) _ -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt: ParStmt" (ppr stmt) + +rn_rec_stmt _ stmt@(L _ (TransformStmt {})) _ -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt: TransformStmt" (ppr stmt) + +rn_rec_stmt _ stmt@(L _ (GroupStmt {})) _ -- Syntactically illegal in mdo + = pprPanic "rn_rec_stmt: GroupStmt" (ppr stmt) + +rn_rec_stmt _ (L _ (LetStmt EmptyLocalBinds)) _ + = panic "rn_rec_stmt: LetStmt EmptyLocalBinds" + +rn_rec_stmts :: [Name] -> [(LStmtLR Name RdrName, FreeVars)] -> RnM [Segment (LStmt Name)] +rn_rec_stmts bndrs stmts = mapM (uncurry (rn_rec_stmt bndrs)) stmts `thenM` \ segs_s -> + return (concat segs_s) --------------------------------------------- addFwdRefs :: [Segment a] -> [Segment a] @@ -909,23 +1140,24 @@ glomSegments ((defs,uses,fwds,stmt) : segs) ---------------------------------------------------- -segsToStmts :: [Segment [LStmt Name]] +segsToStmts :: Stmt Name -- A RecStmt with the SyntaxOps filled in + -> [Segment [LStmt Name]] -> FreeVars -- Free vars used 'later' -> ([LStmt Name], FreeVars) -segsToStmts [] fvs_later = ([], fvs_later) -segsToStmts ((defs, uses, fwds, ss) : segs) fvs_later +segsToStmts _ [] fvs_later = ([], fvs_later) +segsToStmts empty_rec_stmt ((defs, uses, fwds, ss) : segs) fvs_later = ASSERT( not (null ss) ) (new_stmt : later_stmts, later_uses `plusFV` uses) where - (later_stmts, later_uses) = segsToStmts segs fvs_later + (later_stmts, later_uses) = segsToStmts empty_rec_stmt segs fvs_later new_stmt | non_rec = head ss - | otherwise = L (getLoc (head ss)) $ - RecStmt ss (nameSetToList used_later) (nameSetToList fwds) - [] emptyLHsBinds - where - non_rec = isSingleton ss && isEmptyNameSet fwds - used_later = defs `intersectNameSet` later_uses + | otherwise = L (getLoc (head ss)) rec_stmt + rec_stmt = empty_rec_stmt { recS_stmts = ss + , recS_later_ids = nameSetToList used_later + , recS_rec_ids = nameSetToList fwds } + non_rec = isSingleton ss && isEmptyNameSet fwds + used_later = defs `intersectNameSet` later_uses -- The ones needed after the RecStmt \end{code} @@ -937,19 +1169,26 @@ segsToStmts ((defs, uses, fwds, ss) : segs) fvs_later \begin{code} srcSpanPrimLit :: SrcSpan -> HsExpr Name -srcSpanPrimLit span = HsLit (HsStringPrim (mkFastString (showSDoc (ppr span)))) +srcSpanPrimLit span = HsLit (HsStringPrim (mkFastString (showSDocOneLine (ppr span)))) -mkAssertErrorExpr :: RnM (HsExpr Name, FreeVars) +mkAssertErrorExpr :: RnM (HsExpr Name) -- Return an expression for (assertError "Foo.hs:27") mkAssertErrorExpr = getSrcSpanM `thenM` \ sloc -> - let - expr = HsApp (L sloc (HsVar assertErrorName)) - (L sloc (srcSpanPrimLit sloc)) - in - returnM (expr, emptyFVs) + return (HsApp (L sloc (HsVar assertErrorName)) + (L sloc (srcSpanPrimLit sloc))) \end{code} +Note [Adding the implicit parameter to 'assert'] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The renamer transforms (assert e1 e2) to (assert "Foo.hs:27" e1 e2). +By doing this in the renamer we allow the typechecker to just see the +expanded application and do the right thing. But it's not really +the Right Thing because there's no way to "undo" if you want to see +the original source code. We'll have fix this in due course, when +we care more about being able to reconstruct the exact original +program. + %************************************************************************ %* * \subsubsection{Errors} @@ -957,15 +1196,153 @@ mkAssertErrorExpr %************************************************************************ \begin{code} -patSynErr e = do { addErr (sep [ptext SLIT("Pattern syntax in expression context:"), +checkEmptyStmts :: HsStmtContext Name -> RnM () +-- We've seen an empty sequence of Stmts... is that ok? +checkEmptyStmts ctxt + = unless (okEmpty ctxt) (addErr (emptyErr ctxt)) + +okEmpty :: HsStmtContext a -> Bool +okEmpty (PatGuard {}) = True +okEmpty _ = False + +emptyErr :: HsStmtContext Name -> SDoc +emptyErr (ParStmtCtxt {}) = ptext (sLit "Empty statement group in parallel comprehension") +emptyErr (TransformStmtCtxt {}) = ptext (sLit "Empty statement group preceding 'group' or 'then'") +emptyErr ctxt = ptext (sLit "Empty") <+> pprStmtContext ctxt + +---------------------- +checkLastStmt :: HsStmtContext Name + -> LStmt RdrName + -> RnM (LStmt RdrName) +checkLastStmt ctxt lstmt@(L loc stmt) + = case ctxt of + ListComp -> check_comp + MonadComp -> check_comp + PArrComp -> check_comp + DoExpr -> check_do + MDoExpr -> check_do + _ -> check_other + where + check_do -- Expect ExprStmt, and change it to LastStmt + = case stmt of + ExprStmt e _ _ _ -> return (L loc (mkLastStmt e)) + LastStmt {} -> return lstmt -- "Deriving" clauses may generate a + -- LastStmt directly (unlike the parser) + _ -> do { addErr (hang last_error 2 (ppr stmt)); return lstmt } + last_error = (ptext (sLit "The last statement in") <+> pprAStmtContext ctxt + <+> ptext (sLit "must be an expression")) + + check_comp -- Expect LastStmt; this should be enforced by the parser! + = case stmt of + LastStmt {} -> return lstmt + _ -> pprPanic "checkLastStmt" (ppr lstmt) + + check_other -- Behave just as if this wasn't the last stmt + = do { checkStmt ctxt lstmt; return lstmt } + +-- Checking when a particular Stmt is ok +checkStmt :: HsStmtContext Name + -> LStmt RdrName + -> RnM () +checkStmt ctxt (L _ stmt) + = do { dflags <- getDOpts + ; case okStmt dflags ctxt stmt of + Nothing -> return () + Just extra -> addErr (msg $$ extra) } + where + msg = sep [ ptext (sLit "Unexpected") <+> pprStmtCat stmt <+> ptext (sLit "statement") + , ptext (sLit "in") <+> pprAStmtContext ctxt ] + +pprStmtCat :: Stmt a -> SDoc +pprStmtCat (TransformStmt {}) = ptext (sLit "transform") +pprStmtCat (GroupStmt {}) = ptext (sLit "group") +pprStmtCat (LastStmt {}) = ptext (sLit "return expression") +pprStmtCat (ExprStmt {}) = ptext (sLit "exprssion") +pprStmtCat (BindStmt {}) = ptext (sLit "binding") +pprStmtCat (LetStmt {}) = ptext (sLit "let") +pprStmtCat (RecStmt {}) = ptext (sLit "rec") +pprStmtCat (ParStmt {}) = ptext (sLit "parallel") + +------------ +isOK, notOK :: Maybe SDoc +isOK = Nothing +notOK = Just empty + +okStmt, okDoStmt, okCompStmt :: DynFlags -> HsStmtContext Name + -> Stmt RdrName -> Maybe SDoc +-- Return Nothing if OK, (Just extra) if not ok +-- The "extra" is an SDoc that is appended to an generic error message +okStmt _ (PatGuard {}) stmt + = case stmt of + ExprStmt {} -> isOK + BindStmt {} -> isOK + LetStmt {} -> isOK + _ -> notOK + +okStmt dflags (ParStmtCtxt ctxt) stmt + = case stmt of + LetStmt (HsIPBinds {}) -> notOK + _ -> okStmt dflags ctxt stmt + +okStmt dflags (TransformStmtCtxt ctxt) stmt + = okStmt dflags ctxt stmt + +okStmt dflags ctxt stmt + | isDoExpr ctxt = okDoStmt dflags ctxt stmt + | isListCompExpr ctxt = okCompStmt dflags ctxt stmt + | otherwise = pprPanic "okStmt" (pprStmtContext ctxt) + +---------------- +okDoStmt dflags _ stmt + = case stmt of + RecStmt {} + | Opt_DoRec `xopt` dflags -> isOK + | otherwise -> Just (ptext (sLit "Use -XDoRec")) + BindStmt {} -> isOK + LetStmt {} -> isOK + ExprStmt {} -> isOK + _ -> notOK + + +---------------- +okCompStmt dflags _ stmt + = case stmt of + BindStmt {} -> isOK + LetStmt {} -> isOK + ExprStmt {} -> isOK + ParStmt {} + | Opt_ParallelListComp `xopt` dflags -> isOK + | otherwise -> Just (ptext (sLit "Use -XParallelListComp")) + TransformStmt {} + | Opt_TransformListComp `xopt` dflags -> isOK + | otherwise -> Just (ptext (sLit "Use -XTransformListComp")) + GroupStmt {} + | Opt_TransformListComp `xopt` dflags -> isOK + | otherwise -> Just (ptext (sLit "Use -XTransformListComp")) + LastStmt {} -> notOK + RecStmt {} -> notOK + +--------- +checkTupleSection :: [HsTupArg RdrName] -> RnM () +checkTupleSection args + = do { tuple_section <- xoptM Opt_TupleSections + ; checkErr (all tupArgPresent args || tuple_section) msg } + where + msg = ptext (sLit "Illegal tuple section: use -XTupleSections") + +--------- +sectionErr :: HsExpr RdrName -> SDoc +sectionErr expr + = hang (ptext (sLit "A section must be enclosed in parentheses")) + 2 (ptext (sLit "thus:") <+> (parens (ppr expr))) + +patSynErr :: HsExpr RdrName -> RnM (HsExpr Name, FreeVars) +patSynErr e = do { addErr (sep [ptext (sLit "Pattern syntax in expression context:"), nest 4 (ppr e)]) ; return (EWildPat, emptyFVs) } -parStmtErr = addErr (ptext SLIT("Illegal parallel list comprehension: use -fglasgow-exts")) - +badIpBinds :: Outputable a => SDoc -> a -> SDoc badIpBinds what binds - = hang (ptext SLIT("Implicit-parameter bindings illegal in") <+> what) + = hang (ptext (sLit "Implicit-parameter bindings illegal in") <+> what) 2 (ppr binds) \end{code} - -