X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnExpr.lhs;h=97697a050a371eca785a667ee80aef8addc7446b;hb=73641e01ee9dfbe83f8c6225c1f6ae2e7d621b63;hp=613b37be92d35e2bac91607d54ae28d5c8fde047;hpb=7a3bd641457666e10d0a47be9f22762e03defbf0;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnExpr.lhs b/ghc/compiler/rename/RnExpr.lhs index 613b37b..97697a0 100644 --- a/ghc/compiler/rename/RnExpr.lhs +++ b/ghc/compiler/rename/RnExpr.lhs @@ -1,121 +1,64 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[RnExpr]{Renaming of expressions} Basically dependency analysis. -Handles @Match@, @GRHSsAndBinds@, @HsExpr@, and @Qualifier@ datatypes. In +Handles @Match@, @GRHSs@, @HsExpr@, and @Qualifier@ datatypes. In general, all of these functions return a renamed thing, and a set of free variables. \begin{code} -#include "HsVersions.h" - module RnExpr ( - rnMatch, rnGRHSsAndBinds, rnPat, + rnMatch, rnGRHSs, rnExpr, rnExprs, rnStmts, checkPrecMatch ) where -IMP_Ubiq() -IMPORT_DELOOPER(RnLoop) -- break the RnPass/RnExpr/RnBinds loops +#include "HsVersions.h" + +import {-# SOURCE #-} RnSource ( rnSrcDecls, rnBindsAndThen, rnBinds ) + +-- RnSource imports RnBinds.rnTopMonoBinds, RnExpr.rnExpr +-- RnBinds imports RnExpr.rnMatch, etc +-- RnExpr imports [boot] RnSource.rnSrcDecls, RnSource.rnBinds import HsSyn import RdrHsSyn import RnHsSyn -import RnMonad +import TcRnMonad import RnEnv -import PrelInfo ( numClass_RDR, fractionalClass_RDR, eqClass_RDR, ccallableClass_RDR, - creturnableClass_RDR, monadZeroClass_RDR, enumClass_RDR, - negate_RDR - ) -import TysPrim ( charPrimTyCon, addrPrimTyCon, intPrimTyCon, - floatPrimTyCon, doublePrimTyCon - ) -import TyCon ( TyCon ) -import ErrUtils ( addErrLoc, addShortErrLocLine ) -import Name -import Pretty -import UniqFM ( lookupUFM{-, ufmToList ToDo:rm-} ) -import UniqSet ( emptyUniqSet, unitUniqSet, - unionUniqSets, unionManyUniqSets, - SYN_IE(UniqSet) - ) -import Util ( Ord3(..), removeDups, panic ) +import RnNames ( importsFromLocalDecls ) +import RnTypes ( rnHsTypeFVs, rnPat, litFVs, rnOverLit, rnPatsAndThen, + dupFieldErr, precParseErr, sectionPrecErr, patSigErr ) +import CmdLineOpts ( DynFlag(..), opt_IgnoreAsserts ) +import BasicTypes ( Fixity(..), FixityDirection(..), IPName(..), + defaultFixity, negateFixity, compareFixity ) +import PrelNames ( hasKey, assertIdKey, + foldrName, buildName, + cCallableClassName, cReturnableClassName, + enumClassName, + splitName, fstName, sndName, ioDataConName, + replicatePName, mapPName, filterPName, + crossPName, zipPName, toPName, + enumFromToPName, enumFromThenToPName, assertErrorName, + negateName, monadNames, mfixName ) +#ifdef GHCI +import DsMeta ( qTyConName ) +#endif +import Name ( Name, nameOccName ) +import NameSet +import UnicodeUtil ( stringToUtf8 ) +import UniqFM ( isNullUFM ) +import UniqSet ( emptyUniqSet ) +import Util ( isSingleton ) +import List ( intersectBy, unzip4 ) +import ListSetOps ( removeDups ) +import Outputable +import FastString \end{code} -********************************************************* -* * -\subsection{Patterns} -* * -********************************************************* - -\begin{code} -rnPat :: RdrNamePat -> RnMS s RenamedPat - -rnPat WildPatIn = returnRn WildPatIn - -rnPat (VarPatIn name) - = lookupRn name `thenRn` \ vname -> - returnRn (VarPatIn vname) - -rnPat (LitPatIn lit) - = litOccurrence lit `thenRn_` - lookupImplicitOccRn eqClass_RDR `thenRn_` -- Needed to find equality on pattern - returnRn (LitPatIn lit) - -rnPat (LazyPatIn pat) - = rnPat pat `thenRn` \ pat' -> - returnRn (LazyPatIn pat') - -rnPat (AsPatIn name pat) - = rnPat pat `thenRn` \ pat' -> - lookupRn name `thenRn` \ vname -> - returnRn (AsPatIn vname pat') - -rnPat (ConPatIn con pats) - = lookupRn con `thenRn` \ con' -> - mapRn rnPat pats `thenRn` \ patslist -> - returnRn (ConPatIn con' patslist) - -rnPat (ConOpPatIn pat1 con pat2) - = rnOpPat pat1 con pat2 - --- Negated patters can only be literals, and they are dealt with --- by negating the literal at compile time, not by using the negation --- operation in Num. So we don't need to make an implicit reference --- to negate_RDR. -rnPat neg@(NegPatIn pat) - = checkRn (valid_neg_pat pat) (negPatErr neg) - `thenRn_` - rnPat pat `thenRn` \ pat' -> - returnRn (NegPatIn pat') - where - valid_neg_pat (LitPatIn (HsInt _)) = True - valid_neg_pat (LitPatIn (HsFrac _)) = True - valid_neg_pat _ = False - -rnPat (ParPatIn pat) - = rnPat pat `thenRn` \ pat' -> - returnRn (ParPatIn pat') - -rnPat (ListPatIn pats) - = addImplicitOccRn listType_name `thenRn_` - mapRn rnPat pats `thenRn` \ patslist -> - returnRn (ListPatIn patslist) - -rnPat (TuplePatIn pats) - = addImplicitOccRn (tupleType_name (length pats)) `thenRn_` - mapRn rnPat pats `thenRn` \ patslist -> - returnRn (TuplePatIn patslist) - -rnPat (RecPatIn con rpats) - = lookupRn con `thenRn` \ con' -> - rnRpats rpats `thenRn` \ rpats' -> - returnRn (RecPatIn con' rpats') -\end{code} - ************************************************************************ * * \subsection{Match} @@ -123,52 +66,65 @@ rnPat (RecPatIn con rpats) ************************************************************************ \begin{code} -rnMatch :: RdrNameMatch -> RnMS s (RenamedMatch, FreeVars) - -rnMatch (PatMatch pat match) - = bindLocalsRn "pattern" binders $ \ new_binders -> - rnPat pat `thenRn` \ pat' -> - rnMatch match `thenRn` \ (match', fvMatch) -> - returnRn (PatMatch pat' match', fvMatch `minusNameSet` mkNameSet new_binders) - where - binders = collectPatBinders pat - -rnMatch (GRHSMatch grhss_and_binds) - = rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) -> - returnRn (GRHSMatch grhss_and_binds', fvs) +rnMatch :: HsMatchContext Name -> RdrNameMatch -> RnM (RenamedMatch, FreeVars) + +rnMatch ctxt match@(Match pats maybe_rhs_sig grhss) + = addSrcLoc (getMatchLoc match) $ + + -- Deal with the rhs type signature + bindPatSigTyVars rhs_sig_tys $ + doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts -> + (case maybe_rhs_sig of + Nothing -> returnM (Nothing, emptyFVs) + Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenM` \ (ty', ty_fvs) -> + returnM (Just ty', ty_fvs) + | otherwise -> addErr (patSigErr ty) `thenM_` + returnM (Nothing, emptyFVs) + ) `thenM` \ (maybe_rhs_sig', ty_fvs) -> + + -- Now the main event + rnPatsAndThen ctxt pats $ \ pats' -> + rnGRHSs ctxt grhss `thenM` \ (grhss', grhss_fvs) -> + + returnM (Match pats' maybe_rhs_sig' grhss', grhss_fvs `plusFV` ty_fvs) + -- The bindPatSigTyVars and rnPatsAndThen will remove the bound FVs + where + rhs_sig_tys = case maybe_rhs_sig of + Nothing -> [] + Just ty -> [ty] + doc_sig = text "In a result type-signature" \end{code} + %************************************************************************ %* * -\subsubsection{Guarded right-hand sides (GRHSsAndBinds)} +\subsubsection{Guarded right-hand sides (GRHSs)} %* * %************************************************************************ \begin{code} -rnGRHSsAndBinds :: RdrNameGRHSsAndBinds -> RnMS s (RenamedGRHSsAndBinds, FreeVars) +rnGRHSs :: HsMatchContext Name -> RdrNameGRHSs -> RnM (RenamedGRHSs, FreeVars) + +rnGRHSs ctxt (GRHSs grhss binds _) + = rnBindsAndThen binds $ \ binds' -> + mapFvRn (rnGRHS ctxt) grhss `thenM` \ (grhss', fvGRHSs) -> + returnM (GRHSs grhss' binds' placeHolderType, fvGRHSs) -rnGRHSsAndBinds (GRHSsAndBindsIn grhss binds) - = rnBinds binds $ \ binds' -> - rnGRHSs grhss `thenRn` \ (grhss', fvGRHS) -> - returnRn (GRHSsAndBindsIn grhss' binds', fvGRHS) +rnGRHS ctxt (GRHS guarded locn) + = addSrcLoc locn $ + doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts -> + checkM (opt_GlasgowExts || is_standard_guard guarded) + (addWarn (nonStdGuardErr guarded)) `thenM_` + + rnStmts (PatGuard ctxt) guarded `thenM` \ (guarded', fvs) -> + returnM (GRHS guarded' locn, fvs) where - rnGRHSs [] = returnRn ([], emptyNameSet) - - rnGRHSs (grhs:grhss) - = rnGRHS grhs `thenRn` \ (grhs', fvs) -> - rnGRHSs grhss `thenRn` \ (grhss', fvss) -> - returnRn (grhs' : grhss', fvs `unionNameSets` fvss) - - rnGRHS (GRHS guard expr locn) - = pushSrcLocRn locn $ - rnExpr guard `thenRn` \ (guard', fvsg) -> - rnExpr expr `thenRn` \ (expr', fvse) -> - returnRn (GRHS guard' expr' locn, fvsg `unionNameSets` fvse) - - rnGRHS (OtherwiseGRHS expr locn) - = pushSrcLocRn locn $ - rnExpr expr `thenRn` \ (expr', fvs) -> - returnRn (OtherwiseGRHS expr' locn, fvs) + -- Standard Haskell 1.4 guards are just a single boolean + -- expression, rather than a list of qualifiers as in the + -- Glasgow extension + is_standard_guard [ResultStmt _ _] = True + is_standard_guard [ExprStmt _ _ _, ResultStmt _ _] = True + is_standard_guard other = False \end{code} %************************************************************************ @@ -178,287 +134,596 @@ rnGRHSsAndBinds (GRHSsAndBindsIn grhss binds) %************************************************************************ \begin{code} -rnExprs :: [RdrNameHsExpr] -> RnMS s ([RenamedHsExpr], FreeVars) +rnExprs :: [RdrNameHsExpr] -> RnM ([RenamedHsExpr], FreeVars) +rnExprs ls = rnExprs' ls emptyUniqSet + where + rnExprs' [] acc = returnM ([], acc) + rnExprs' (expr:exprs) acc + = rnExpr expr `thenM` \ (expr', fvExpr) -> -rnExprs [] = returnRn ([], emptyNameSet) + -- Now we do a "seq" on the free vars because typically it's small + -- or empty, especially in very long lists of constants + let + acc' = acc `plusFV` fvExpr + in + (grubby_seqNameSet acc' rnExprs') exprs acc' `thenM` \ (exprs', fvExprs) -> + returnM (expr':exprs', fvExprs) -rnExprs (expr:exprs) - = rnExpr expr `thenRn` \ (expr', fvExpr) -> - rnExprs exprs `thenRn` \ (exprs', fvExprs) -> - returnRn (expr':exprs', fvExpr `unionNameSets` 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 \end{code} -Variables. We look up the variable and return the resulting name. The -interesting question is what the free-variable set should be. We -don't want to return imported or prelude things as free vars. So we -look at the Name returned from the lookup, and make it part of the -free-var set iff if it's a LocallyDefined Name. -\end{itemize} +Variables. We look up the variable and return the resulting name. \begin{code} -rnExpr :: RdrNameHsExpr -> RnMS s (RenamedHsExpr, FreeVars) +rnExpr :: RdrNameHsExpr -> RnM (RenamedHsExpr, FreeVars) rnExpr (HsVar v) - = lookupOccRn v `thenRn` \ vname -> - returnRn (HsVar vname, if isLocallyDefined vname - then unitNameSet vname - else emptyUniqSet) + = lookupOccRn v `thenM` \ name -> + if name `hasKey` assertIdKey && not opt_IgnoreAsserts then + -- We expand it to (GHC.Err.assertError location_string) + mkAssertErrorExpr + else + -- The normal case. Even if the Id was 'assert', if we are + -- ignoring assertions we leave it as GHC.Base.assert; + -- this function just ignores its first arg. + returnM (HsVar name, unitFV name) + +rnExpr (HsIPVar v) + = newIPName v `thenM` \ name -> + let + fvs = case name of + Linear _ -> mkFVs [splitName, fstName, sndName] + Dupable _ -> emptyFVs + in + returnM (HsIPVar name, fvs) rnExpr (HsLit lit) - = litOccurrence lit `thenRn_` - returnRn (HsLit lit, emptyNameSet) + = litFVs lit `thenM` \ fvs -> + returnM (HsLit lit, fvs) + +rnExpr (HsOverLit lit) + = rnOverLit lit `thenM` \ (lit', fvs) -> + returnM (HsOverLit lit', fvs) rnExpr (HsLam match) - = rnMatch match `thenRn` \ (match', fvMatch) -> - returnRn (HsLam match', fvMatch) + = rnMatch LambdaExpr match `thenM` \ (match', fvMatch) -> + returnM (HsLam match', fvMatch) rnExpr (HsApp fun arg) - = rnExpr fun `thenRn` \ (fun',fvFun) -> - rnExpr arg `thenRn` \ (arg',fvArg) -> - returnRn (HsApp fun' arg', fvFun `unionNameSets` fvArg) - -rnExpr (OpApp e1 (HsVar op) e2) = rnOpApp e1 op e2 - -rnExpr (NegApp e n) = completeNegApp (rnExpr e) + = rnExpr fun `thenM` \ (fun',fvFun) -> + rnExpr arg `thenM` \ (arg',fvArg) -> + returnM (HsApp fun' arg', fvFun `plusFV` fvArg) + +rnExpr (OpApp e1 op _ e2) + = rnExpr e1 `thenM` \ (e1', fv_e1) -> + rnExpr e2 `thenM` \ (e2', fv_e2) -> + rnExpr op `thenM` \ (op'@(HsVar op_name), fv_op) -> + + -- Deal with fixity + -- When renaming code synthesised from "deriving" declarations + -- we're in Interface mode, and we should ignore fixity; assume + -- that the deriving code generator got the association correct + -- Don't even look up the fixity when in interface mode + getModeRn `thenM` \ mode -> + (if isInterfaceMode mode + then returnM (OpApp e1' op' defaultFixity e2') + else lookupFixityRn op_name `thenM` \ fixity -> + mkOpAppRn e1' op' fixity e2' + ) `thenM` \ final_e -> + + returnM (final_e, + fv_e1 `plusFV` fv_op `plusFV` fv_e2) + +rnExpr (NegApp e _) + = rnExpr 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) - = rnExpr e `thenRn` \ (e', fvs_e) -> - returnRn (HsPar e', fvs_e) - -rnExpr (SectionL expr op) - = rnExpr expr `thenRn` \ (expr', fvs_expr) -> - rnExpr op `thenRn` \ (op', fvs_op) -> - returnRn (SectionL expr' op', fvs_op `unionNameSets` fvs_expr) - -rnExpr (SectionR op expr) - = rnExpr op `thenRn` \ (op', fvs_op) -> - rnExpr expr `thenRn` \ (expr', fvs_expr) -> - returnRn (SectionR op' expr', fvs_op `unionNameSets` fvs_expr) - -rnExpr (CCall fun args may_gc is_casm fake_result_ty) - = lookupImplicitOccRn ccallableClass_RDR `thenRn_` - lookupImplicitOccRn creturnableClass_RDR `thenRn_` - rnExprs args `thenRn` \ (args', fvs_args) -> - returnRn (CCall fun args' may_gc is_casm fake_result_ty, fvs_args) - -rnExpr (HsSCC label expr) - = rnExpr expr `thenRn` \ (expr', fvs_expr) -> - returnRn (HsSCC label expr', fvs_expr) + = rnExpr e `thenM` \ (e', fvs_e) -> + returnM (HsPar e', fvs_e) + +-- Template Haskell extensions +#ifdef GHCI +rnExpr (HsBracket br_body loc) + = addSrcLoc loc $ + checkGHCI (thErr "bracket") `thenM_` + rnBracket br_body `thenM` \ (body', fvs_e) -> + returnM (HsBracket body' loc, fvs_e `addOneFV` qTyConName) + -- We use the Q tycon as a proxy to haul in all the smart + -- constructors; see the hack in RnIfaces + +rnExpr (HsSplice n e loc) + = addSrcLoc loc $ + checkGHCI (thErr "splice") `thenM_` + newLocalsRn [(n,loc)] `thenM` \ [n'] -> + rnExpr e `thenM` \ (e', fvs_e) -> + returnM (HsSplice n' e' loc, fvs_e `addOneFV` qTyConName) + -- The qTyCon brutally pulls in all the meta stuff + +rnExpr (HsReify (Reify flavour name)) + = checkGHCI (thErr "reify") `thenM_` + lookupGlobalOccRn name `thenM` \ name' -> + -- For now, we can only reify top-level things + returnM (HsReify (Reify flavour name'), mkFVs [name', qTyConName]) + -- The qTyCon brutally pulls in all the meta stuff +#endif + +rnExpr section@(SectionL expr op) + = rnExpr expr `thenM` \ (expr', fvs_expr) -> + rnExpr op `thenM` \ (op', fvs_op) -> + checkSectionPrec InfixL section op' expr' `thenM_` + returnM (SectionL expr' op', fvs_op `plusFV` fvs_expr) + +rnExpr section@(SectionR op expr) + = rnExpr op `thenM` \ (op', fvs_op) -> + rnExpr expr `thenM` \ (expr', fvs_expr) -> + checkSectionPrec InfixR section op' expr' `thenM_` + returnM (SectionR op' expr', fvs_op `plusFV` fvs_expr) + +rnExpr (HsCCall fun args may_gc is_casm _) + -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls + = rnExprs args `thenM` \ (args', fvs_args) -> + returnM (HsCCall fun args' may_gc is_casm placeHolderType, + fvs_args `plusFV` mkFVs [cCallableClassName, + cReturnableClassName, + ioDataConName]) + +rnExpr (HsSCC lbl expr) + = rnExpr expr `thenM` \ (expr', fvs_expr) -> + returnM (HsSCC lbl expr', fvs_expr) rnExpr (HsCase expr ms src_loc) - = pushSrcLocRn src_loc $ - rnExpr expr `thenRn` \ (new_expr, e_fvs) -> - mapAndUnzipRn rnMatch ms `thenRn` \ (new_ms, ms_fvs) -> - returnRn (HsCase new_expr new_ms src_loc, unionManyNameSets (e_fvs : ms_fvs)) + = addSrcLoc src_loc $ + rnExpr expr `thenM` \ (new_expr, e_fvs) -> + mapFvRn (rnMatch CaseAlt) ms `thenM` \ (new_ms, ms_fvs) -> + returnM (HsCase new_expr new_ms src_loc, e_fvs `plusFV` ms_fvs) rnExpr (HsLet binds expr) - = rnBinds binds $ \ binds' -> - rnExpr expr `thenRn` \ (expr',fvExpr) -> - returnRn (HsLet binds' expr', fvExpr) - -rnExpr (HsDo stmts src_loc) - = pushSrcLocRn src_loc $ - lookupImplicitOccRn monadZeroClass_RDR `thenRn_` -- Forces Monad to come too - rnStmts stmts `thenRn` \ (stmts', fvStmts) -> - returnRn (HsDo stmts' src_loc, fvStmts) - -rnExpr (ListComp expr quals) - = addImplicitOccRn listType_name `thenRn_` - rnQuals expr quals `thenRn` \ ((expr', quals'), fvs) -> - returnRn (ListComp expr' quals', fvs) - -rnExpr (ExplicitList exps) - = addImplicitOccRn listType_name `thenRn_` - rnExprs exps `thenRn` \ (exps', fvs) -> - returnRn (ExplicitList exps', fvs) - -rnExpr (ExplicitTuple exps) - = addImplicitOccRn (tupleType_name (length exps)) `thenRn_` - rnExprs exps `thenRn` \ (exps', fvExps) -> - returnRn (ExplicitTuple exps', fvExps) - -rnExpr (RecordCon (HsVar con) rbinds) - = lookupOccRn con `thenRn` \ conname -> - rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) -> - returnRn (RecordCon (HsVar conname) rbinds', fvRbinds) + = rnBindsAndThen binds $ \ binds' -> + rnExpr expr `thenM` \ (expr',fvExpr) -> + returnM (HsLet binds' expr', fvExpr) + +rnExpr e@(HsDo do_or_lc stmts _ _ src_loc) + = addSrcLoc src_loc $ + rnStmts do_or_lc stmts `thenM` \ (stmts', fvs) -> + + -- Check the statement list ends in an expression + case last stmts' of { + ResultStmt _ _ -> returnM () ; + _ -> addErr (doStmtListErr do_or_lc e) + } `thenM_` + + -- Generate the rebindable syntax for the monad + mapAndUnzipM lookupSyntaxName + (syntax_names do_or_lc) `thenM` \ (monad_names', monad_fvs) -> + + returnM (HsDo do_or_lc stmts' monad_names' placeHolderType src_loc, + fvs `plusFV` implicit_fvs do_or_lc `plusFV` plusFVs monad_fvs) + where + implicit_fvs PArrComp = mkFVs [replicatePName, mapPName, filterPName, crossPName, zipPName] + implicit_fvs ListComp = mkFVs [foldrName, buildName] + implicit_fvs DoExpr = emptyFVs + implicit_fvs MDoExpr = emptyFVs + + syntax_names DoExpr = monadNames + syntax_names MDoExpr = monadNames ++ [mfixName] + syntax_names other = [] + +rnExpr (ExplicitList _ exps) + = rnExprs exps `thenM` \ (exps', fvs) -> + returnM (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name) + +rnExpr (ExplicitPArr _ exps) + = rnExprs exps `thenM` \ (exps', fvs) -> + returnM (ExplicitPArr placeHolderType exps', + fvs `addOneFV` toPName `addOneFV` parrTyCon_name) + +rnExpr (ExplicitTuple exps boxity) + = rnExprs exps `thenM` \ (exps', fvs) -> + returnM (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name) + where + tycon_name = tupleTyCon_name boxity (length exps) + +rnExpr (RecordCon con_id rbinds) + = lookupOccRn con_id `thenM` \ conname -> + rnRbinds "construction" rbinds `thenM` \ (rbinds', fvRbinds) -> + returnM (RecordCon conname rbinds', fvRbinds `addOneFV` conname) rnExpr (RecordUpd expr rbinds) - = rnExpr expr `thenRn` \ (expr', fvExpr) -> - rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) -> - returnRn (RecordUpd expr' rbinds', fvExpr `unionNameSets` fvRbinds) + = rnExpr expr `thenM` \ (expr', fvExpr) -> + rnRbinds "update" rbinds `thenM` \ (rbinds', fvRbinds) -> + returnM (RecordUpd expr' rbinds', fvExpr `plusFV` fvRbinds) rnExpr (ExprWithTySig expr pty) - = rnExpr expr `thenRn` \ (expr', fvExpr) -> - rnHsType pty `thenRn` \ pty' -> - returnRn (ExprWithTySig expr' pty', fvExpr) + = rnExpr expr `thenM` \ (expr', fvExpr) -> + rnHsTypeFVs doc pty `thenM` \ (pty', fvTy) -> + returnM (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy) + where + doc = text "In an expression type signature" rnExpr (HsIf p b1 b2 src_loc) - = pushSrcLocRn src_loc $ - rnExpr p `thenRn` \ (p', fvP) -> - rnExpr b1 `thenRn` \ (b1', fvB1) -> - rnExpr b2 `thenRn` \ (b2', fvB2) -> - returnRn (HsIf p' b1' b2' src_loc, unionManyNameSets [fvP, fvB1, fvB2]) + = addSrcLoc src_loc $ + rnExpr p `thenM` \ (p', fvP) -> + rnExpr b1 `thenM` \ (b1', fvB1) -> + rnExpr b2 `thenM` \ (b2', fvB2) -> + returnM (HsIf p' b1' b2' src_loc, plusFVs [fvP, fvB1, fvB2]) + +rnExpr (HsType a) + = rnHsTypeFVs doc a `thenM` \ (t, fvT) -> + returnM (HsType t, fvT) + where + doc = text "In a type argument" rnExpr (ArithSeqIn seq) - = lookupImplicitOccRn enumClass_RDR `thenRn_` - rn_seq seq `thenRn` \ (new_seq, fvs) -> - returnRn (ArithSeqIn new_seq, fvs) - where - rn_seq (From expr) - = rnExpr expr `thenRn` \ (expr', fvExpr) -> - returnRn (From expr', fvExpr) - - rn_seq (FromThen expr1 expr2) - = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) -> - rnExpr expr2 `thenRn` \ (expr2', fvExpr2) -> - returnRn (FromThen expr1' expr2', fvExpr1 `unionNameSets` fvExpr2) - - rn_seq (FromTo expr1 expr2) - = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) -> - rnExpr expr2 `thenRn` \ (expr2', fvExpr2) -> - returnRn (FromTo expr1' expr2', fvExpr1 `unionNameSets` fvExpr2) - - rn_seq (FromThenTo expr1 expr2 expr3) - = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) -> - rnExpr expr2 `thenRn` \ (expr2', fvExpr2) -> - rnExpr expr3 `thenRn` \ (expr3', fvExpr3) -> - returnRn (FromThenTo expr1' expr2' expr3', - unionManyNameSets [fvExpr1, fvExpr2, fvExpr3]) + = rnArithSeq seq `thenM` \ (new_seq, fvs) -> + returnM (ArithSeqIn new_seq, fvs `addOneFV` enumClassName) + +rnExpr (PArrSeqIn seq) + = rnArithSeq seq `thenM` \ (new_seq, fvs) -> + returnM (PArrSeqIn new_seq, + fvs `plusFV` mkFVs [enumFromToPName, enumFromThenToPName]) +\end{code} + +These three are pattern syntax appearing in expressions. +Since all the symbols are reservedops we can simply reject them. +We return a (bogus) EWildPat in each case. + +\begin{code} +rnExpr e@EWildPat = addErr (patSynErr e) `thenM_` + returnM (EWildPat, emptyFVs) + +rnExpr e@(EAsPat _ _) = addErr (patSynErr e) `thenM_` + returnM (EWildPat, emptyFVs) + +rnExpr e@(ELazyPat _) = addErr (patSynErr e) `thenM_` + returnM (EWildPat, emptyFVs) \end{code} %************************************************************************ %* * -\subsubsection{@Rbinds@s and @Rpats@s: in record expressions} + Arithmetic sequences %* * %************************************************************************ \begin{code} -rnRbinds str rbinds - = mapRn field_dup_err dup_fields `thenRn_` - mapAndUnzipRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind_s) -> - returnRn (rbinds', unionManyNameSets fvRbind_s) - where - (_, dup_fields) = removeDups cmp [ f | (f,_,_) <- rbinds ] +rnArithSeq (From expr) + = rnExpr expr `thenM` \ (expr', fvExpr) -> + returnM (From expr', fvExpr) + +rnArithSeq (FromThen expr1 expr2) + = rnExpr expr1 `thenM` \ (expr1', fvExpr1) -> + rnExpr expr2 `thenM` \ (expr2', fvExpr2) -> + returnM (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2) + +rnArithSeq (FromTo expr1 expr2) + = rnExpr expr1 `thenM` \ (expr1', fvExpr1) -> + rnExpr expr2 `thenM` \ (expr2', fvExpr2) -> + returnM (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2) + +rnArithSeq (FromThenTo expr1 expr2 expr3) + = rnExpr expr1 `thenM` \ (expr1', fvExpr1) -> + rnExpr expr2 `thenM` \ (expr2', fvExpr2) -> + rnExpr expr3 `thenM` \ (expr3', fvExpr3) -> + returnM (FromThenTo expr1' expr2' expr3', + plusFVs [fvExpr1, fvExpr2, fvExpr3]) +\end{code} - field_dup_err dups = addErrRn (dupFieldErr str dups) - rn_rbind (field, expr, pun) - = lookupOccRn field `thenRn` \ fieldname -> - rnExpr expr `thenRn` \ (expr', fvExpr) -> - returnRn ((fieldname, expr', pun), fvExpr) +%************************************************************************ +%* * +\subsubsection{@Rbinds@s and @Rpats@s: in record expressions} +%* * +%************************************************************************ -rnRpats rpats - = mapRn field_dup_err dup_fields `thenRn_` - mapRn rn_rpat rpats +\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 cmp [ f | (f,_,_) <- rpats ] + (_, dup_fields) = removeDups compare [ f | (f,_) <- rbinds ] - field_dup_err dups = addErrRn (dupFieldErr "pattern" dups) + field_dup_err dups = addErr (dupFieldErr str dups) - rn_rpat (field, pat, pun) - = lookupOccRn field `thenRn` \ fieldname -> - rnPat pat `thenRn` \ pat' -> - returnRn (fieldname, pat', pun) + rn_rbind (field, expr) + = lookupGlobalOccRn field `thenM` \ fieldname -> + rnExpr expr `thenM` \ (expr', fvExpr) -> + returnM ((fieldname, expr'), fvExpr `addOneFV` fieldname) \end{code} %************************************************************************ %* * -\subsubsection{@Qualifier@s: in list comprehensions} + Template Haskell brackets %* * %************************************************************************ -Note that although some bound vars may appear in the free var set for -the first qual, these will eventually be removed by the caller. For -example, if we have @[p | r <- s, q <- r, p <- q]@, when doing -@[q <- r, p <- q]@, the free var set for @q <- r@ will -be @{r}@, and the free var set for the entire Quals will be @{r}@. This -@r@ will be removed only when we finally return from examining all the -Quals. - \begin{code} -rnQuals :: RdrNameHsExpr -> [RdrNameQual] - -> RnMS s ((RenamedHsExpr, [RenamedQual]), FreeVars) - -rnQuals expr [qual] -- must be at least one qual - = rnQual qual $ \ new_qual -> - rnExpr expr `thenRn` \ (expr', fvs) -> - returnRn ((expr', [new_qual]), fvs) - -rnQuals expr (qual: quals) - = rnQual qual $ \ qual' -> - rnQuals expr quals `thenRn` \ ((expr', quals'), fv_quals) -> - returnRn ((expr', qual' : quals'), fv_quals) - +rnBracket (ExpBr e) = rnExpr e `thenM` \ (e', fvs) -> + returnM (ExpBr e', fvs) +rnBracket (PatBr p) = rnPat p `thenM` \ (p', fvs) -> + returnM (PatBr p', fvs) +rnBracket (TypBr t) = rnHsTypeFVs doc t `thenM` \ (t', fvs) -> + returnM (TypBr t', fvs) + where + doc = ptext SLIT("In a Template-Haskell quoted type") +rnBracket (DecBr group) + = importsFromLocalDecls group `thenM` \ (rdr_env, avails) -> + -- Discard avails (not useful here) + + updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl }) $ + + rnSrcDecls group `thenM` \ (tcg_env, group', fvs) -> + -- Discard the tcg_env; it contains only extra info about fixity + + returnM (DecBr group', fvs) +\end{code} --- rnQual :: RdrNameQual --- -> (RenamedQual -> RnMS s (a,FreeVars)) --- -> RnMS s (a,FreeVars) --- Because of mutual recursion the actual type is a bit less general than this [Haskell 1.2] +%************************************************************************ +%* * +\subsubsection{@Stmt@s: in @do@ expressions} +%* * +%************************************************************************ -rnQual (GeneratorQual pat expr) thing_inside - = rnExpr expr `thenRn` \ (expr', fv_expr) -> - bindLocalsRn "pattern in list comprehension" binders $ \ new_binders -> - rnPat pat `thenRn` \ pat' -> +\begin{code} +rnStmts :: HsStmtContext Name -> [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars) + +rnStmts MDoExpr stmts = rnMDoStmts stmts +rnStmts ctxt stmts = rnNormalStmts ctxt stmts + +rnNormalStmts :: HsStmtContext Name -> [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars) +-- Used for cases *other* than recursive mdo +-- Implements nested scopes + +rnNormalStmts ctxt [] = returnM ([], emptyFVs) + -- Happens at the end of the sub-lists of a ParStmts + +rnNormalStmts ctxt (ExprStmt expr _ src_loc : stmts) + = addSrcLoc src_loc $ + rnExpr expr `thenM` \ (expr', fv_expr) -> + rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) -> + returnM (ExprStmt expr' placeHolderType src_loc : stmts', + fv_expr `plusFV` fvs) + +rnNormalStmts ctxt [ResultStmt expr src_loc] + = addSrcLoc src_loc $ + rnExpr expr `thenM` \ (expr', fv_expr) -> + returnM ([ResultStmt expr' src_loc], fv_expr) + +rnNormalStmts ctxt (BindStmt pat expr src_loc : stmts) + = addSrcLoc src_loc $ + rnExpr expr `thenM` \ (expr', fv_expr) -> + -- The binders do not scope over the expression + + rnPatsAndThen (StmtCtxt ctxt) [pat] $ \ [pat'] -> + rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) -> + returnM (BindStmt pat' expr' src_loc : stmts', + fv_expr `plusFV` fvs) -- fv_expr shouldn't really be filtered by + -- the rnPatsAndThen, but it does not matter + +rnNormalStmts ctxt (LetStmt binds : stmts) + = checkErr (ok ctxt binds) (badIpBinds binds) `thenM_` + rnBindsAndThen binds ( \ binds' -> + rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) -> + returnM (LetStmt binds' : stmts', fvs)) + where + -- We do not allow implicit-parameter bindings in a parallel + -- list comprehension. I'm not sure what it might mean. + ok (ParStmtCtxt _) (IPBinds _ _) = False + ok _ _ = True - thing_inside (GeneratorQual pat' expr') `thenRn` \ (result, fvs) -> - returnRn (result, fv_expr `unionNameSets` (fvs `minusNameSet` mkNameSet new_binders)) +rnNormalStmts ctxt (ParStmt stmtss : stmts) + = mapFvRn (rnNormalStmts (ParStmtCtxt ctxt)) stmtss `thenM` \ (stmtss', fv_stmtss) -> + let + bndrss = map collectStmtsBinders stmtss' + in + foldlM checkBndrs [] bndrss `thenM` \ new_binders -> + bindLocalNamesFV new_binders $ + -- Note: binders are returned in scope order, so one may + -- shadow the next; e.g. x <- xs; x <- ys + rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) -> + returnM (ParStmtOut (bndrss `zip` stmtss') : stmts', + fv_stmtss `plusFV` fvs) + where - binders = collectPatBinders pat + checkBndrs all_bndrs bndrs + = checkErr (null common) (err (head common)) `thenM_` + returnM (bndrs ++ all_bndrs) + where + common = intersectBy eqOcc all_bndrs bndrs -rnQual (FilterQual expr) thing_inside - = rnExpr expr `thenRn` \ (expr', fv_expr) -> - thing_inside (FilterQual expr') `thenRn` \ (result, fvs) -> - returnRn (result, fv_expr `unionNameSets` fvs) + eqOcc n1 n2 = nameOccName n1 == nameOccName n2 + err v = ptext SLIT("Duplicate binding in parallel list comprehension for:") + <+> quotes (ppr v) -rnQual (LetQual binds) thing_inside - = rnBinds binds $ \ binds' -> - thing_inside (LetQual binds') +rnNormalStmts ctxt stmts = pprPanic "rnNormalStmts" (ppr stmts) \end{code} %************************************************************************ %* * -\subsubsection{@Stmt@s: in @do@ expressions} +\subsubsection{Precedence Parsing} %* * %************************************************************************ \begin{code} -rnStmts :: [RdrNameStmt] -> RnMS s ([RenamedStmt], FreeVars) - -rnStmts [stmt@(ExprStmt expr src_loc)] -- last stmt must be ExprStmt - = pushSrcLocRn src_loc $ - rnExpr expr `thenRn` \ (expr', fv_expr) -> - returnRn ([ExprStmt expr' src_loc], fv_expr) +type Defs = NameSet +type Uses = NameSet -- Same as FreeVars really +type FwdRefs = NameSet +type Segment = (Defs, + Uses, -- May include defs + FwdRefs, -- A subset of uses that are + -- (a) used before they are bound in this segment, or + -- (b) used here, and bound in subsequent segments + [RenamedStmt]) + +---------------------------------------------------- +rnMDoStmts :: [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars) +rnMDoStmts stmts + = -- Step1: bring all the binders of the mdo into scope + bindLocalsRn doc (collectStmtsBinders stmts) $ \ _ -> + + -- 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 + mappM rn_mdo_stmt stmts `thenM` \ segs -> + 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 + + -- 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_w_fvs = segsToStmts grouped_segs + in + returnM stmts_w_fvs + where + doc = text "In a mdo-expression" + +---------------------------------------------------- +rn_mdo_stmt :: RdrNameStmt -> RnM Segment + -- Assumes all binders are already in scope + -- Turns each stmt into a singleton Stmt + +rn_mdo_stmt (ExprStmt expr _ src_loc) + = addSrcLoc src_loc (rnExpr expr) `thenM` \ (expr', fvs) -> + returnM (emptyNameSet, fvs, emptyNameSet, + [ExprStmt expr' placeHolderType src_loc]) + +rn_mdo_stmt (ResultStmt expr src_loc) + = addSrcLoc src_loc (rnExpr expr) `thenM` \ (expr', fvs) -> + returnM (emptyNameSet, fvs, emptyNameSet, + [ResultStmt expr' src_loc]) + +rn_mdo_stmt (BindStmt pat expr src_loc) + = addSrcLoc src_loc $ + rnExpr expr `thenM` \ (expr', fv_expr) -> + rnPat pat `thenM` \ (pat', fv_pat) -> + let + bndrs = mkNameSet (collectPatBinders pat') + fvs = fv_expr `plusFV` fv_pat + in + returnM (bndrs, fvs, bndrs `intersectNameSet` fvs, + [BindStmt pat' expr' src_loc]) -rnStmts (stmt:stmts) - = rnStmt stmt $ \ stmt' -> - rnStmts stmts `thenRn` \ (stmts', fv_stmts) -> - returnRn (stmt':stmts', fv_stmts) +rn_mdo_stmt (LetStmt binds) + = rnBinds binds `thenM` \ (binds', fv_binds) -> + returnM (mkNameSet (collectHsBinders binds'), + fv_binds, emptyNameSet, [LetStmt binds']) +rn_mdo_stmt stmt@(ParStmt _) -- Syntactically illegal in mdo + = pprPanic "rn_mdo_stmt" (ppr stmt) --- rnStmt :: RdrNameStmt -> (RenamedStmt -> RnMS s (a, FreeVars)) -> RnMS s (a, FreeVars) --- Because of mutual recursion the actual type is a bit less general than this [Haskell 1.2] -rnStmt (BindStmt pat expr src_loc) thing_inside - = pushSrcLocRn src_loc $ - rnExpr expr `thenRn` \ (expr', fv_expr) -> - bindLocalsRn "pattern in do binding" binders $ \ new_binders -> - rnPat pat `thenRn` \ pat' -> +addFwdRefs :: [Segment] -> [Segment] +-- So far the segments only have forward refs *within* the Stmt +-- (which happens for bind: x <- ...x...) +-- This function adds the cross-seg fwd ref info - thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ (result, fvs) -> - returnRn (result, fv_expr `unionNameSets` (fvs `minusNameSet` mkNameSet new_binders)) +addFwdRefs pairs + = fst (foldr mk_seg ([], emptyNameSet) pairs) where - binders = collectPatBinders pat - -rnStmt (ExprStmt expr src_loc) thing_inside - = pushSrcLocRn src_loc $ - rnExpr expr `thenRn` \ (expr', fv_expr) -> - thing_inside (ExprStmt expr' src_loc) `thenRn` \ (result, fvs) -> - returnRn (result, fv_expr `unionNameSets` fvs) - -rnStmt (LetStmt binds) thing_inside - = rnBinds binds $ \ binds' -> - thing_inside (LetStmt binds') + mk_seg (defs, uses, fwds, stmts) (segs, seg_defs) + = (new_seg : segs, all_defs) + where + new_seg = (defs, uses, new_fwds, stmts) + all_defs = seg_defs `unionNameSets` defs + new_fwds = fwds `unionNameSets` (uses `intersectNameSet` seg_defs) + -- Add the downstream fwd refs here + +---------------------------------------------------- +-- Glomming the singleton segments of an mdo into +-- minimal recursive groups. +-- +-- At first I thought this was just strongly connected components, but +-- there's an important constraint: the order of the stmts must not change. +-- +-- Consider +-- mdo { x <- ...y... +-- p <- z +-- y <- ...x... +-- q <- x +-- z <- y +-- r <- x } +-- +-- Here, the first stmt mention 'y', which is bound in the third. +-- But that means that the innocent second stmt (p <- z) gets caught +-- up in the recursion. And that in turn means that the binding for +-- 'z' has to be included... and so on. +-- +-- Start at the tail { r <- x } +-- Now add the next one { z <- y ; r <- x } +-- Now add one more { q <- x ; z <- y ; r <- x } +-- Now one more... but this time we have to group a bunch into rec +-- { rec { y <- ...x... ; q <- x ; z <- y } ; r <- x } +-- Now one more, which we can add on without a rec +-- { p <- z ; +-- rec { y <- ...x... ; q <- x ; z <- y } ; +-- r <- x } +-- Finally we add the last one; since it mentions y we have to +-- glom it togeher with the first two groups +-- { rec { x <- ...y...; p <- z ; y <- ...x... ; +-- q <- x ; z <- y } ; +-- r <- x } + +glomSegments :: [Segment] -> [Segment] + +glomSegments [seg] = [seg] +glomSegments ((defs,uses,fwds,stmts) : segs) + -- Actually stmts will always be a singleton + = (seg_defs, seg_uses, seg_fwds, seg_stmts) : others + where + segs' = glomSegments segs + (extras, others) = grab uses segs' + (ds, us, fs, ss) = unzip4 extras + + seg_defs = plusFVs ds `plusFV` defs + seg_uses = plusFVs us `plusFV` uses + seg_fwds = plusFVs fs `plusFV` fwds + seg_stmts = stmts ++ concat ss + + grab :: NameSet -- The client + -> [Segment] + -> ([Segment], -- Needed by the 'client' + [Segment]) -- Not needed by the client + -- The result is simply a split of the input + grab uses dus + = (reverse yeses, reverse noes) + where + (noes, yeses) = span not_needed (reverse dus) + not_needed (defs,_,_,_) = not (intersectsNameSet defs uses) + + +---------------------------------------------------- +segsToStmts :: [Segment] -> ([RenamedStmt], FreeVars) + +segsToStmts [] = ([], emptyFVs) +segsToStmts ((defs, uses, fwds, ss) : segs) + = (new_stmt : later_stmts, later_uses `plusFV` uses) + where + (later_stmts, later_uses) = segsToStmts segs + new_stmt | non_rec = head ss + | otherwise = RecStmt rec_names ss [] + where + non_rec = isSingleton ss && isEmptyNameSet fwds + rec_names = nameSetToList (fwds `plusFV` (defs `intersectNameSet` later_uses)) + -- The names for the fixpoint are + -- (a) the ones needed after the RecStmt + -- (b) the forward refs within the fixpoint \end{code} %************************************************************************ @@ -467,167 +732,162 @@ rnStmt (LetStmt binds) thing_inside %* * %************************************************************************ -@rnOpApp@ deals with operator applications. It does some rearrangement of -the expression so that the precedences are right. This must be done on the -expression *before* renaming, because fixity info applies to the things -the programmer actually wrote. - -\begin{code} -rnOpApp (NegApp e11 n) op e2 - = lookupFixity op `thenRn` \ (Fixity op_prec op_dir) -> - if op_prec > 6 then - -- negate precedence 6 wired in - -- (-x)*y ==> -(x*y) - completeNegApp (rnOpApp e11 op e2) - else - completeOpApp (completeNegApp (rnExpr e11)) op (rnExpr e2) - -rnOpApp (OpApp e11 (HsVar op1) e12) op e2 - = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) -> - lookupFixity op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) -> - -- pprTrace "rnOpApp:" (ppCat [ppr PprDebug op, ppInt op_prec, ppr PprDebug op1, ppInt op1_prec]) $ - case (op1_prec `cmp` op_prec) of - LT_ -> rearrange - EQ_ -> case (op1_dir, op_dir) of - (InfixR, InfixR) -> rearrange - (InfixL, InfixL) -> dont_rearrange - _ -> addErrRn (precParseErr (op1,op1_fix) (op,op_fix)) `thenRn_` - dont_rearrange - GT__ -> dont_rearrange - where - rearrange = rnOpApp e11 op1 (OpApp e12 (HsVar op) e2) - dont_rearrange = completeOpApp (rnOpApp e11 op1 e12) op (rnExpr e2) - -rnOpApp e1 op e2 = completeOpApp (rnExpr e1) op (rnExpr e2) +@mkOpAppRn@ deals with operator fixities. The argument expressions +are assumed to be already correctly arranged. It needs the fixities +recorded in the OpApp nodes, because fixity info applies to the things +the programmer actually wrote, so you can't find it out from the Name. -completeOpApp rn_e1 op rn_e2 - = rn_e1 `thenRn` \ (e1', fvs1) -> - rn_e2 `thenRn` \ (e2', fvs2) -> - rnExpr (HsVar op) `thenRn` \ (op', fvs3) -> - returnRn (OpApp e1' op' e2', fvs1 `unionNameSets` fvs2 `unionNameSets` fvs3) - -completeNegApp rn_expr - = rn_expr `thenRn` \ (e', fvs_e) -> - lookupImplicitOccRn negate_RDR `thenRn` \ neg -> - returnRn (NegApp e' (HsVar neg), fvs_e) -\end{code} +Furthermore, the second argument is guaranteed not to be another +operator application. Why? Because the parser parses all +operator appications left-associatively, EXCEPT negation, which +we need to handle specially. \begin{code} -rnOpPat p1@(NegPatIn p11) op p2 - = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) -> - if op_prec > 6 then - -- negate precedence 6 wired in - addErrRn (precParseNegPatErr (op,op_fix)) `thenRn_` - rnOpPat p11 op p2 `thenRn` \ op_pat -> - returnRn (NegPatIn op_pat) - else - completeOpPat (rnPat p1) op (rnPat p2) - -rnOpPat (ConOpPatIn p11 op1 p12) op p2 - = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) -> - lookupFixity op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) -> - case (op1_prec `cmp` op_prec) of - LT_ -> rearrange - EQ_ -> case (op1_dir, op_dir) of - (InfixR, InfixR) -> rearrange - (InfixL, InfixL) -> dont_rearrange - _ -> addErrRn (precParseErr (op1,op1_fix) (op,op_fix)) `thenRn_` - dont_rearrange - GT__ -> dont_rearrange +mkOpAppRn :: RenamedHsExpr -- Left operand; already rearranged + -> RenamedHsExpr -> Fixity -- Operator and fixity + -> RenamedHsExpr -- Right operand (not an OpApp, but might + -- be a NegApp) + -> RnM RenamedHsExpr + +--------------------------- +-- (e11 `op1` e12) `op2` e2 +mkOpAppRn e1@(OpApp e11 op1 fix1 e12) op2 fix2 e2 + | nofix_error + = addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenM_` + returnM (OpApp e1 op2 fix2 e2) + + | associate_right + = mkOpAppRn e12 op2 fix2 e2 `thenM` \ new_e -> + returnM (OpApp e11 op1 fix1 new_e) where - rearrange = rnOpPat p11 op1 (ConOpPatIn p12 op p2) - dont_rearrange = completeOpPat (rnOpPat p11 op1 p12) op (rnPat p2) - - -rnOpPat p1 op p2 = completeOpPat (rnPat p1) op (rnPat p2) - -completeOpPat rn_p1 op rn_p2 - = rn_p1 `thenRn` \ p1' -> - rn_p2 `thenRn` \ p2' -> - lookupRn op `thenRn` \ op' -> - returnRn (ConOpPatIn p1' op' p2') + (nofix_error, associate_right) = compareFixity fix1 fix2 + +--------------------------- +-- (- neg_arg) `op` e2 +mkOpAppRn e1@(NegApp neg_arg neg_name) op2 fix2 e2 + | nofix_error + = addErr (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenM_` + returnM (OpApp e1 op2 fix2 e2) + + | associate_right + = mkOpAppRn neg_arg op2 fix2 e2 `thenM` \ new_e -> + returnM (NegApp new_e neg_name) + where + (nofix_error, associate_right) = compareFixity negateFixity fix2 + +--------------------------- +-- e1 `op` - neg_arg +mkOpAppRn e1 op1 fix1 e2@(NegApp neg_arg _) -- NegApp can occur on the right + | not associate_right -- We *want* right association + = addErr (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenM_` + returnM (OpApp e1 op1 fix1 e2) + where + (_, associate_right) = compareFixity fix1 negateFixity + +--------------------------- +-- Default case +mkOpAppRn e1 op fix e2 -- Default case, no rearrangment + = ASSERT2( right_op_ok fix e2, + ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2 + ) + returnM (OpApp e1 op fix e2) + +-- Parser left-associates everything, but +-- derived instances may have correctly-associated things to +-- in the right operarand. So we just check that the right operand is OK +right_op_ok fix1 (OpApp _ _ fix2 _) + = not error_please && associate_right + where + (error_please, associate_right) = compareFixity fix1 fix2 +right_op_ok fix1 other + = True + +-- Parser initially makes negation bind more tightly than any other operator +mkNegAppRn neg_arg neg_name + = +#ifdef DEBUG + getModeRn `thenM` \ mode -> + ASSERT( not_op_app mode neg_arg ) +#endif + returnM (NegApp neg_arg neg_name) + +not_op_app SourceMode (OpApp _ _ _ _) = False +not_op_app mode other = True \end{code} \begin{code} -checkPrecMatch :: Bool -> RdrName -> RdrNameMatch -> RnMS s () +checkPrecMatch :: Bool -> Name -> RenamedMatch -> RnM () checkPrecMatch False fn match - = returnRn () -checkPrecMatch True op (PatMatch p1 (PatMatch p2 (GRHSMatch _))) - = checkPrec op p1 False `thenRn_` - checkPrec op p2 True -checkPrecMatch True op _ - = panic "checkPrecMatch" - -checkPrec op (ConOpPatIn _ op1 _) right - = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) -> - lookupFixity op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) -> + = returnM () + +checkPrecMatch True op (Match (p1:p2:_) _ _) + -- True indicates an infix lhs + = getModeRn `thenM` \ mode -> + -- See comments with rnExpr (OpApp ...) + if isInterfaceMode mode + then returnM () + else checkPrec op p1 False `thenM_` + checkPrec op p2 True + +checkPrecMatch True op _ = panic "checkPrecMatch" + +checkPrec op (ConPatIn op1 (InfixCon _ _)) right + = lookupFixityRn op `thenM` \ op_fix@(Fixity op_prec op_dir) -> + lookupFixityRn op1 `thenM` \ op1_fix@(Fixity op1_prec op1_dir) -> let inf_ok = op1_prec > op_prec || (op1_prec == op_prec && (op1_dir == InfixR && op_dir == InfixR && right || op1_dir == InfixL && op_dir == InfixL && not right)) - info = (op,op_fix) - info1 = (op1,op1_fix) + info = (ppr_op op, op_fix) + info1 = (ppr_op op1, op1_fix) (infol, infor) = if right then (info, info1) else (info1, info) in - checkRn inf_ok (precParseErr infol infor) - -checkPrec op (NegPatIn _) right - = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) -> - checkRn (op_prec <= 6) (precParseNegPatErr (op,op_fix)) + checkErr inf_ok (precParseErr infol infor) checkPrec op pat right - = returnRn () + = returnM () + +-- Check precedence of (arg op) or (op arg) respectively +-- If arg is itself an operator application, then either +-- (a) its precedence must be higher than that of op +-- (b) its precedency & associativity must be the same as that of op +checkSectionPrec direction section op arg + = case arg of + OpApp _ op fix _ -> go_for_it (ppr_op op) fix + NegApp _ _ -> go_for_it pp_prefix_minus negateFixity + other -> returnM () + where + HsVar op_name = op + go_for_it pp_arg_op arg_fix@(Fixity arg_prec assoc) + = lookupFixityRn op_name `thenM` \ op_fix@(Fixity op_prec _) -> + checkErr (op_prec < arg_prec + || op_prec == arg_prec && direction == assoc) + (sectionPrecErr (ppr_op op_name, op_fix) + (pp_arg_op, arg_fix) section) \end{code} + %************************************************************************ %* * -\subsubsection{Literals} +\subsubsection{Assertion utils} %* * %************************************************************************ -When literals occur we have to make sure that the types and classes they involve -are made available. - \begin{code} -litOccurrence (HsChar _) - = addImplicitOccRn charType_name - -litOccurrence (HsCharPrim _) - = addImplicitOccRn (getName charPrimTyCon) - -litOccurrence (HsString _) - = addImplicitOccRn listType_name `thenRn_` - addImplicitOccRn charType_name - -litOccurrence (HsStringPrim _) - = addImplicitOccRn (getName addrPrimTyCon) - -litOccurrence (HsInt _) - = lookupImplicitOccRn numClass_RDR `thenRn_` -- Int and Integer are forced in by Num - returnRn () - -litOccurrence (HsFrac _) - = lookupImplicitOccRn fractionalClass_RDR `thenRn_` -- ... similarly Rational - returnRn () - -litOccurrence (HsIntPrim _) - = addImplicitOccRn (getName intPrimTyCon) - -litOccurrence (HsFloatPrim _) - = addImplicitOccRn (getName floatPrimTyCon) - -litOccurrence (HsDoublePrim _) - = addImplicitOccRn (getName doublePrimTyCon) - -litOccurrence (HsLitLit _) - = lookupImplicitOccRn ccallableClass_RDR `thenRn_` - returnRn () +mkAssertErrorExpr :: RnM (RenamedHsExpr, FreeVars) +-- Return an expression for (assertError "Foo.hs:27") +mkAssertErrorExpr + = getSrcLocM `thenM` \ sloc -> + let + expr = HsApp (HsVar assertErrorName) (HsLit msg) + msg = HsStringPrim (mkFastString (stringToUtf8 (showSDoc (ppr sloc)))) + in + returnM (expr, unitFV assertErrorName) \end{code} - %************************************************************************ %* * \subsubsection{Errors} @@ -635,20 +895,31 @@ litOccurrence (HsLitLit _) %************************************************************************ \begin{code} -dupFieldErr str (dup:rest) sty - = ppBesides [ppStr "duplicate field name `", ppr sty dup, ppStr "' in record ", ppStr str] +ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name +pp_prefix_minus = ptext SLIT("prefix `-'") + +nonStdGuardErr guard + = hang (ptext + SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)") + ) 4 (ppr guard) -negPatErr pat sty - = ppSep [ppStr "prefix `-' not applied to literal in pattern", ppr sty pat] +patSynErr e + = sep [ptext SLIT("Pattern syntax in expression context:"), + nest 4 (ppr e)] -precParseNegPatErr op sty - = ppHang (ppStr "precedence parsing error") - 4 (ppBesides [ppStr "prefix `-' has lower precedence than ", pp_op sty op, ppStr " in pattern"]) +doStmtListErr do_or_lc e + = sep [quotes (text binder_name) <+> ptext SLIT("statements must end in expression:"), + nest 4 (ppr e)] + where + binder_name = case do_or_lc of + MDoExpr -> "mdo" + other -> "do" -precParseErr op1 op2 sty - = ppHang (ppStr "precedence parsing error") - 4 (ppBesides [ppStr "cannot mix ", pp_op sty op1, ppStr " and ", pp_op sty op2, - ppStr " in the same infix expression"]) +thErr what + = ptext SLIT("Template Haskell") <+> text what <+> + ptext SLIT("illegal in a stage-1 compiler") -pp_op sty (op, fix) = ppBesides [pprSym sty op, ppLparen, ppr sty fix, ppRparen] +badIpBinds binds + = hang (ptext SLIT("Implicit-parameter bindings illegal in a parallel list comprehension:")) 4 + (ppr binds) \end{code}