X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FdeSugar%2FDsExpr.lhs;h=34a3a202bcff2336507eb5311a07135b1b98e022;hp=5fb0ec8f490b5d8b7cdccc79cd1b2ef0be6bee29;hb=a8427a4125e9b78e88a487eeabf018f1c6e8bc08;hpb=5c9c3660697f18ae9dcd95e254249d3dd908b94e diff --git a/compiler/deSugar/DsExpr.lhs b/compiler/deSugar/DsExpr.lhs index 5fb0ec8..34a3a20 100644 --- a/compiler/deSugar/DsExpr.lhs +++ b/compiler/deSugar/DsExpr.lhs @@ -1,66 +1,52 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % -\section[DsExpr]{Matching expressions (Exprs)} + +Desugaring exporessions. \begin{code} module DsExpr ( dsExpr, dsLExpr, dsLocalBinds, dsValBinds, dsLit ) where #include "HsVersions.h" -#if defined(GHCI) && defined(BREAKPOINT) -import Foreign.StablePtr ( newStablePtr, castStablePtrToPtr ) -import GHC.Exts ( Ptr(..), Int(..), addr2Int# ) -import IOEnv ( ioToIOEnv ) -import PrelNames ( breakpointJumpName, breakpointCondJumpName ) -import TysWiredIn ( unitTy ) -import TypeRep ( Type(..) ) -import TyCon ( isUnLiftedTyCon ) -#endif -import Match ( matchWrapper, matchSinglePat, matchEquations ) -import MatchLit ( dsLit, dsOverLit ) -import DsBinds ( dsLHsBinds, dsCoercion ) -import DsGRHSs ( dsGuarded ) -import DsListComp ( dsListComp, dsPArrComp ) -import DsUtils ( mkErrorAppDs, mkStringExpr, mkConsExpr, mkNilExpr, - extractMatchResult, cantFailMatchResult, matchCanFail, - mkCoreTupTy, selectSimpleMatchVarL, lookupEvidence, selectMatchVar ) -import DsArrows ( dsProcExpr ) + +import Match +import MatchLit +import DsBinds +import DsGRHSs +import DsListComp +import DsUtils +import DsArrows import DsMonad +import Name #ifdef GHCI +import PrelNames -- Template Haskell stuff iff bootstrapped -import DsMeta ( dsBracket ) +import DsMeta #endif import HsSyn -import TcHsSyn ( hsPatType, mkVanillaTuplePat ) +import TcHsSyn -- NB: The desugarer, which straddles the source and Core worlds, sometimes --- needs to see source types (newtypes etc), and sometimes not --- So WATCH OUT; check each use of split*Ty functions. --- Sigh. This is a pain. - -import TcType ( tcSplitAppTy, tcSplitFunTys, tcTyConAppTyCon, - tcTyConAppArgs, isUnLiftedType, Type, mkAppTy ) -import Type ( splitFunTys, isUnboxedTupleType, mkFunTy ) +-- needs to see source types +import TcType +import Type import CoreSyn -import CoreUtils ( exprType, mkIfThenElse, bindNonRec ) - -import CostCentre ( mkUserCC ) -import Id ( Id, idType, idName, idDataCon ) -import PrelInfo ( rEC_CON_ERROR_ID ) -import DataCon ( DataCon, dataConWrapId, dataConFieldLabels, dataConInstOrigArgTys ) -import DataCon ( isVanillaDataCon ) -import TyCon ( FieldLabel, tyConDataCons ) -import TysWiredIn ( tupleCon ) -import BasicTypes ( RecFlag(..), Boxity(..), ipNameName ) -import PrelNames ( toPName, - returnMName, bindMName, thenMName, failMName, - mfixName ) -import SrcLoc ( Located(..), unLoc, getLoc, noLoc ) -import Util ( zipEqual, zipWithEqual ) -import Bag ( bagToList ) +import CoreUtils + +import CostCentre +import Id +import PrelInfo +import DataCon +import TysWiredIn +import BasicTypes +import PrelNames +import SrcLoc +import Util +import Bag import Outputable import FastString \end{code} @@ -118,11 +104,13 @@ ds_val_bind (NonRecursive, hsbinds) body -- below. Then pattern-match would fail. Urk.) putSrcSpanDs loc $ case bind of - FunBind { fun_id = L _ fun, fun_matches = matches, fun_co_fn = co_fn } - -> matchWrapper (FunRhs (idName fun)) matches `thenDs` \ (args, rhs) -> + FunBind { fun_id = L _ fun, fun_matches = matches, fun_co_fn = co_fn, + fun_tick = tick, fun_infix = inf } + -> matchWrapper (FunRhs (idName fun ) inf) matches `thenDs` \ (args, rhs) -> ASSERT( null args ) -- Functions aren't lifted - ASSERT( isIdCoercion co_fn ) - returnDs (bindNonRec fun rhs body_w_exports) + ASSERT( isIdHsWrapper co_fn ) + mkOptTickBox tick rhs `thenDs` \ rhs' -> + returnDs (bindNonRec fun rhs' body_w_exports) PatBind {pat_lhs = pat, pat_rhs = grhss, pat_rhs_ty = ty } -> -- let C x# y# = rhs in body @@ -130,9 +118,9 @@ ds_val_bind (NonRecursive, hsbinds) body putSrcSpanDs loc $ do { rhs <- dsGuarded grhss ty ; let upat = unLoc pat - eqn = EqnInfo { eqn_wrap = idWrapper, eqn_pats = [upat], + eqn = EqnInfo { eqn_pats = [upat], eqn_rhs = cantFailMatchResult body_w_exports } - ; var <- selectMatchVar upat ty + ; var <- selectMatchVar upat ; result <- matchEquations PatBindRhs [var] [eqn] (exprType body) ; return (scrungleMatch var rhs result) } @@ -185,6 +173,7 @@ scrungleMatch var scrut body | x == var = Case scrut bndr ty alts scrungle (Let binds body) = Let binds (scrungle body) scrungle other = panic ("scrungleMatch: tuple pattern:\n" ++ showSDoc (ppr other)) + \end{code} %************************************************************************ @@ -195,16 +184,17 @@ scrungleMatch var scrut body \begin{code} dsLExpr :: LHsExpr Id -> DsM CoreExpr + dsLExpr (L loc e) = putSrcSpanDs loc $ dsExpr e dsExpr :: HsExpr Id -> DsM CoreExpr - dsExpr (HsPar e) = dsLExpr e dsExpr (ExprWithTySigOut e _) = dsLExpr e dsExpr (HsVar var) = returnDs (Var var) dsExpr (HsIPVar ip) = returnDs (Var (ipNameName ip)) dsExpr (HsLit lit) = dsLit lit dsExpr (HsOverLit lit) = dsOverLit lit +dsExpr (HsWrap co_fn e) = dsCoercion co_fn (dsExpr e) dsExpr (NegApp expr neg_expr) = do { core_expr <- dsLExpr expr @@ -215,41 +205,10 @@ dsExpr expr@(HsLam a_Match) = matchWrapper LambdaExpr a_Match `thenDs` \ (binders, matching_code) -> returnDs (mkLams binders matching_code) -#if defined(GHCI) && defined(BREAKPOINT) -dsExpr (HsApp (L _ (HsApp realFun@(L _ (HsCoerce _ fun)) (L loc arg))) _) - | HsVar funId <- fun - , idName funId `elem` [breakpointJumpName, breakpointCondJumpName] - , ids <- filter (isValidType . idType) (extractIds arg) - = do dsWarn (text "Extracted ids:" <+> ppr ids <+> ppr (map idType ids)) - stablePtr <- ioToIOEnv $ newStablePtr ids - -- Yes, I know... I'm gonna burn in hell. - let Ptr addr# = castStablePtrToPtr stablePtr - funCore <- dsLExpr realFun - argCore <- dsLExpr (L loc (HsLit (HsInt (fromIntegral (I# (addr2Int# addr#)))))) - hvalCore <- dsLExpr (L loc (extractHVals ids)) - return ((funCore `App` argCore) `App` hvalCore) - where extractIds :: HsExpr Id -> [Id] - extractIds (HsApp fn arg) - | HsVar argId <- unLoc arg - = argId:extractIds (unLoc fn) - | TyApp arg' ts <- unLoc arg - , HsVar argId <- unLoc arg' - = error (showSDoc (ppr ts)) -- argId:extractIds (unLoc fn) - extractIds x = [] - extractHVals ids = ExplicitList unitTy (map (L loc . HsVar) ids) - -- checks for tyvars and unlifted kinds. - isValidType (TyVarTy _) = False - isValidType (FunTy a b) = isValidType a && isValidType b - isValidType (NoteTy _ t) = isValidType t - isValidType (AppTy a b) = isValidType a && isValidType b - isValidType (TyConApp con ts) = not (isUnLiftedTyCon con) && all isValidType ts - isValidType _ = True -#endif - dsExpr expr@(HsApp fun arg) = dsLExpr fun `thenDs` \ core_fun -> dsLExpr arg `thenDs` \ core_arg -> - returnDs (core_fun `App` core_arg) + returnDs (core_fun `mkDsApp` core_arg) \end{code} Operator sections. At first it looks as if we can convert @@ -279,22 +238,12 @@ dsExpr (OpApp e1 op _ e2) -- for the type of y, we need the type of op's 2nd argument dsLExpr e1 `thenDs` \ x_core -> dsLExpr e2 `thenDs` \ y_core -> - returnDs (mkApps core_op [x_core, y_core]) + returnDs (mkDsApps core_op [x_core, y_core]) -dsExpr (SectionL expr op) - = dsLExpr op `thenDs` \ core_op -> - -- for the type of y, we need the type of op's 2nd argument - let - (x_ty:y_ty:_, _) = splitFunTys (exprType core_op) - -- Must look through an implicit-parameter type; - -- newtype impossible; hence Type.splitFunTys - in - dsLExpr expr `thenDs` \ x_core -> - newSysLocalDs x_ty `thenDs` \ x_id -> - newSysLocalDs y_ty `thenDs` \ y_id -> - - returnDs (bindNonRec x_id x_core $ - Lam y_id (mkApps core_op [Var x_id, Var y_id])) +dsExpr (SectionL expr op) -- Desugar (e !) to ((!) e) + = dsLExpr op `thenDs` \ core_op -> + dsLExpr expr `thenDs` \ x_core -> + returnDs (mkDsApp core_op x_core) -- dsLExpr (SectionR op expr) -- \ x -> op x expr dsExpr (SectionR op expr) @@ -309,7 +258,7 @@ dsExpr (SectionR op expr) newSysLocalDs y_ty `thenDs` \ y_id -> returnDs (bindNonRec y_id y_core $ - Lam x_id (mkApps core_op [Var x_id, Var y_id])) + Lam x_id (mkDsApps core_op [Var x_id, Var y_id])) dsExpr (HsSCC cc expr) = dsLExpr expr `thenDs` \ core_expr -> @@ -328,8 +277,10 @@ dsExpr (HsCase discrim matches) matchWrapper CaseAlt matches `thenDs` \ ([discrim_var], matching_code) -> returnDs (scrungleMatch discrim_var core_discrim matching_code) +-- Pepe: The binds are in scope in the body but NOT in the binding group +-- This is to avoid silliness in breakpoints dsExpr (HsLet binds body) - = dsLExpr body `thenDs` \ body' -> + = dsLExpr body `thenDs` \ body' -> dsLocalBinds binds body' -- We need the `ListComp' form to use `deListComp' (rather than the "do" form) @@ -362,20 +313,6 @@ dsExpr (HsIf guard_expr then_expr else_expr) \noindent -\underline{\bf Type lambda and application} -% ~~~~~~~~~~~~~~~~~~~~~~~~~~~ -\begin{code} -dsExpr (TyLam tyvars expr) - = dsLExpr expr `thenDs` \ core_expr -> - returnDs (mkLams tyvars core_expr) - -dsExpr (TyApp expr tys) - = dsLExpr expr `thenDs` \ core_expr -> - returnDs (mkTyApps core_expr tys) -\end{code} - - -\noindent \underline{\bf Various data construction things} % ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} @@ -480,7 +417,7 @@ dsExpr (RecordCon (L _ data_con_id) con_expr rbinds) -- hence TcType.tcSplitFunTys mk_arg (arg_ty, lbl) -- Selector id has the field label as its name - = case [rhs | (L _ sel_id, rhs) <- rbinds, lbl == idName sel_id] of + = case findField (rec_flds rbinds) lbl of (rhs:rhss) -> ASSERT( null rhss ) dsLExpr rhs [] -> mkErrorAppDs rEC_CON_ERROR_ID arg_ty (showSDoc (ppr lbl)) @@ -520,93 +457,51 @@ might do some argument-evaluation first; and may have to throw away some dictionaries. \begin{code} -dsExpr (RecordUpd record_expr [] record_in_ty record_out_ty) +dsExpr expr@(RecordUpd record_expr (HsRecFields { rec_flds = fields }) + cons_to_upd in_inst_tys out_inst_tys) + | null fields = dsLExpr record_expr - -dsExpr expr@(RecordUpd record_expr rbinds record_in_ty record_out_ty) - = dsLExpr record_expr `thenDs` \ record_expr' -> - - -- Desugar the rbinds, and generate let-bindings if - -- necessary so that we don't lose sharing - - let - in_inst_tys = tcTyConAppArgs record_in_ty -- Newtype opaque - out_inst_tys = tcTyConAppArgs record_out_ty -- Newtype opaque - in_out_ty = mkFunTy record_in_ty record_out_ty - - mk_val_arg field old_arg_id - = case [rhs | (L _ sel_id, rhs) <- rbinds, field == idName sel_id] of - (rhs:rest) -> ASSERT(null rest) rhs - [] -> nlHsVar old_arg_id - - mk_alt con - = newSysLocalsDs (dataConInstOrigArgTys con in_inst_tys) `thenDs` \ arg_ids -> - -- This call to dataConInstOrigArgTys won't work for existentials - -- but existentials don't have record types anyway - let - val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg - (dataConFieldLabels con) arg_ids - rhs = foldl (\a b -> nlHsApp a b) - (noLoc $ TyApp (nlHsVar (dataConWrapId con)) - out_inst_tys) - val_args - in - returnDs (mkSimpleMatch [noLoc $ ConPatOut (noLoc con) [] [] emptyLHsBinds - (PrefixCon (map nlVarPat arg_ids)) record_in_ty] - rhs) - in - -- Record stuff doesn't work for existentials + | otherwise + = -- Record stuff doesn't work for existentials -- The type checker checks for this, but we need -- worry only about the constructors that are to be updated - ASSERT2( all isVanillaDataCon cons_to_upd, ppr expr ) + ASSERT2( notNull cons_to_upd && all isVanillaDataCon cons_to_upd, ppr expr ) + + do { record_expr' <- dsLExpr record_expr + ; let -- Awkwardly, for families, the match goes + -- from instance type to family type + tycon = dataConTyCon (head cons_to_upd) + in_ty = mkTyConApp tycon in_inst_tys + in_out_ty = mkFunTy in_ty + (mkFamilyTyConApp tycon out_inst_tys) + + mk_val_arg field old_arg_id + = case findField fields field of + (rhs:rest) -> ASSERT(null rest) rhs + [] -> nlHsVar old_arg_id + + mk_alt con + = ASSERT( isVanillaDataCon con ) + do { arg_ids <- newSysLocalsDs (dataConInstOrigArgTys con in_inst_tys) + -- This call to dataConInstOrigArgTys won't work for existentials + -- but existentials don't have record types anyway + ; let val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg + (dataConFieldLabels con) arg_ids + rhs = foldl (\a b -> nlHsApp a b) + (nlHsTyApp (dataConWrapId con) out_inst_tys) + val_args + pat = mkPrefixConPat con (map nlVarPat arg_ids) in_ty + + ; return (mkSimpleMatch [pat] rhs) } -- It's important to generate the match with matchWrapper, -- and the right hand sides with applications of the wrapper Id -- so that everything works when we are doing fancy unboxing on the -- constructor aguments. - mappM mk_alt cons_to_upd `thenDs` \ alts -> - matchWrapper RecUpd (MatchGroup alts in_out_ty) `thenDs` \ ([discrim_var], matching_code) -> - - returnDs (bindNonRec discrim_var record_expr' matching_code) + ; alts <- mapM mk_alt cons_to_upd + ; ([discrim_var], matching_code) <- matchWrapper RecUpd (MatchGroup alts in_out_ty) - where - updated_fields :: [FieldLabel] - updated_fields = [ idName sel_id | (L _ sel_id,_) <- rbinds] - - -- Get the type constructor from the record_in_ty - -- so that we are sure it'll have all its DataCons - -- (In GHCI, it's possible that some TyCons may not have all - -- their constructors, in a module-loop situation.) - tycon = tcTyConAppTyCon record_in_ty - data_cons = tyConDataCons tycon - cons_to_upd = filter has_all_fields data_cons - - has_all_fields :: DataCon -> Bool - has_all_fields con_id - = all (`elem` con_fields) updated_fields - where - con_fields = dataConFieldLabels con_id -\end{code} - - -\noindent -\underline{\bf Dictionary lambda and application} -% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -@DictLam@ and @DictApp@ turn into the regular old things. -(OLD:) @DictFunApp@ also becomes a curried application, albeit slightly more -complicated; reminiscent of fully-applied constructors. -\begin{code} -dsExpr (DictLam dictvars expr) - = dsLExpr expr `thenDs` \ core_expr -> - returnDs (mkLams dictvars core_expr) - ------------------- - -dsExpr (DictApp expr dicts) -- becomes a curried application - = dsLExpr expr `thenDs` \ core_expr -> - returnDs (foldl (\f d -> f `App` (Var d)) core_expr dicts) - -dsExpr (HsCoerce co_fn e) = dsCoercion co_fn (dsExpr e) + ; return (bindNonRec discrim_var record_expr' matching_code) } \end{code} Here is where we desugar the Template Haskell brackets and escapes @@ -623,6 +518,26 @@ dsExpr (HsSpliceE s) = pprPanic "dsExpr:splice" (ppr s) dsExpr (HsProc pat cmd) = dsProcExpr pat cmd \end{code} +Hpc Support + +\begin{code} +dsExpr (HsTick ix vars e) = do + e' <- dsLExpr e + mkTickBox ix vars e' + +-- There is a problem here. The then and else branches +-- have no free variables, so they are open to lifting. +-- We need someway of stopping this. +-- This will make no difference to binary coverage +-- (did you go here: YES or NO), but will effect accurate +-- tick counting. + +dsExpr (HsBinTick ixT ixF e) = do + e2 <- dsLExpr e + do { ASSERT(exprType e2 `coreEqType` boolTy) + mkBinaryTickBox ixT ixF e2 + } +\end{code} \begin{code} @@ -631,6 +546,11 @@ dsExpr (HsProc pat cmd) = dsProcExpr pat cmd dsExpr (ExprWithTySig _ _) = panic "dsExpr:ExprWithTySig" #endif + +findField :: [HsRecField Id arg] -> Name -> [arg] +findField rbinds lbl + = [rhs | HsRecField { hsRecFieldId = id, hsRecFieldArg = rhs } <- rbinds + , lbl == idName (unLoc id) ] \end{code} %-------------------------------------------------------------------- @@ -659,14 +579,15 @@ dsDo stmts body result_ty go (LetStmt binds : stmts) = do { rest <- go stmts ; dsLocalBinds binds rest } - + go (BindStmt pat rhs bind_op fail_op : stmts) - = do { body <- go stmts + = + do { body <- go stmts ; var <- selectSimpleMatchVarL pat ; match <- matchSinglePat (Var var) (StmtCtxt DoExpr) pat result_ty (cantFailMatchResult body) ; match_code <- handle_failure pat match fail_op - ; rhs' <- dsLExpr rhs + ; rhs' <- dsLExpr rhs ; bind_op' <- dsExpr bind_op ; returnDs (mkApps bind_op' [rhs', Lam var match_code]) } @@ -730,7 +651,7 @@ dsMDo tbl stmts body result_ty ; match_code <- extractMatchResult match fail_expr ; rhs' <- dsLExpr rhs - ; returnDs (mkApps (Var bind_id) [Type (hsPatType pat), Type b_ty, + ; returnDs (mkApps (Var bind_id) [Type (hsLPatType pat), Type b_ty, rhs', Lam var match_code]) } go (RecStmt rec_stmts later_ids rec_ids rec_rets binds : stmts) @@ -748,7 +669,7 @@ dsMDo tbl stmts body result_ty later_ids' = filter (`notElem` mono_rec_ids) later_ids mono_rec_ids = [ id | HsVar id <- rec_rets ] - mfix_app = nlHsApp (noLoc $ TyApp (nlHsVar mfix_id) [tup_ty]) mfix_arg + mfix_app = nlHsApp (nlHsTyApp mfix_id [tup_ty]) mfix_arg mfix_arg = noLoc $ HsLam (MatchGroup [mkSimpleMatch [mfix_pat] body] (mkFunTy tup_ty body_ty)) @@ -765,7 +686,7 @@ dsMDo tbl stmts body result_ty tup_ty = mkCoreTupTy (map idType (later_ids' ++ rec_ids)) -- mkCoreTupTy deals with singleton case - return_app = nlHsApp (noLoc $ TyApp (nlHsVar return_id) [tup_ty]) + return_app = nlHsApp (nlHsTyApp return_id [tup_ty]) (mk_ret_tup rets) mk_wild_pat :: Id -> LPat Id