%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[DsBinds]{Pattern-matching bindings (Binds and MonoBinds)}
+\section[DsBinds]{Pattern-matching bindings (HsBinds and MonoBinds)}
-Handles @Binds@; those at the top level require different handling, in
-that the @Rec@/@NonRec@/etc structure is thrown away (whereas at lower
-levels it is preserved with @let@/@letrec@s).
+Handles @HsBinds@; those at the top level require different handling,
+in that the @Rec@/@NonRec@/etc structure is thrown away (whereas at
+lower levels it is preserved with @let@/@letrec@s).
\begin{code}
-#include "HsVersions.h"
+module DsBinds ( dsHsBinds, dsHsNestedBinds, AutoScc(..) ) where
-module DsBinds (
- dsBinds, dsInstBinds
- ) where
+#include "HsVersions.h"
-IMPORT_Trace -- ToDo: rm (debugging only)
-import AbsSyn -- the stuff being desugared
-import PlainCore -- the output of desugaring;
- -- importing this module also gets all the
- -- CoreSyn utility functions
-import DsMonad -- the monadery used in the desugarer
+import {-# SOURCE #-} DsExpr( dsLExpr )
+import {-# SOURCE #-} Match( matchWrapper )
-import AbsUniType
-import CmdLineOpts ( GlobalSwitch(..), SwitchResult, switchIsOn )
-import CostCentre ( mkAllDictsCC, preludeDictsCostCentre )
-import Inst ( getInstUniType )
-import DsExpr ( dsExpr )
+import DsMonad
import DsGRHSs ( dsGuarded )
import DsUtils
-import Id ( getIdUniType, mkInstId, Inst, Id, DictVar(..) )
-import Match ( matchWrapper )
-import Maybes ( Maybe(..),assocMaybe )
+
+import HsSyn -- lots of things
+import CoreSyn -- lots of things
+import CoreUtils ( exprType, mkInlineMe, mkSCC )
+
+import CmdLineOpts ( opt_AutoSccsOnAllToplevs, opt_AutoSccsOnExportedToplevs )
+import CostCentre ( mkAutoCC, IsCafCC(..) )
+import Id ( idType, idName, isExportedId, isSpecPragmaId, Id )
+import NameSet
+import VarSet
+import Type ( mkTyVarTy, substTyWith )
+import TysWiredIn ( voidTy )
import Outputable
-import Pretty
-import Util
-import ListSetOps ( minusList, intersectLists )
+import SrcLoc ( Located(..) )
+import Maybe ( isJust )
+import Bag ( bagToList )
+import Monad ( foldM )
\end{code}
-
%************************************************************************
%* *
-\subsection[toplevel-and-regular-DsBinds]{Regular and top-level @dsBinds@}
+\subsection[dsMonoBinds]{Desugaring a @MonoBinds@}
%* *
%************************************************************************
-Like @dsBinds@, @dsBind@ returns a @[PlainCoreBinding]@, but it may be
-that some of the binders are of unboxed type. This is sorted out when
-the caller wraps the bindings round an expression.
-
\begin{code}
-dsBinds :: TypecheckedBinds -> DsM [PlainCoreBinding]
-\end{code}
-
-All ``real'' bindings are expressed in terms of the
-@AbsBinds@ construct, which is a massively-complicated ``shorthand'',
-and its desugaring is the subject of section~9.1 in the static
-semantics paper.
-
-(ToDo) For:
-\begin{verbatim}
-AbsBinds [a1, ... ,aj] -- type variables
- [d1, ... ,dk] -- dict variables
- [(l1,g1), ..., (lm,gm)] -- overloaded equivs [Id pairs] (later...)
- [db1=..., ..., dbn=...] -- dict binds
- [vb1=..., ..., vbm=...] -- val binds; note: vb_i = l_i
-\end{verbatim}
-we want to make, in the general case (non-Fozzie translation):
-\begin{verbatim}
- -- tupler-upper:
- tup a1...aj d1...dk =
- let <dict-binds> in
- let(rec) <val-binds> in (vb1,...,vbm) -- NB: == ... in (l1,...,lm)
-
- -- a bunch of selectors:
- g1 a1...aj d1...dk = case (_tup a1...aj d1...dk) of (x1,x2,...,xm) -> x1
- ...
- gm a1...aj d1...dk = case (_tup a1...aj d1...dk) of (x1,x2,...,xm) -> xm
-\end{verbatim}
-But there are lots of special cases.
-
-
-%==============================================
-\subsubsection{Structure cases}
-%==============================================
-
-\begin{code}
-dsBinds (BindWith _ _) = panic "dsBinds:BindWith"
-dsBinds EmptyBinds = returnDs []
-dsBinds (SingleBind bind) = dsBind [] [] id [] bind
+dsHsNestedBinds :: LHsBinds Id -> DsM [(Id,CoreExpr)]
+dsHsNestedBinds binds = dsHsBinds NoSccs binds []
-dsBinds (ThenBinds binds_1 binds_2)
- = andDs (++) (dsBinds binds_1) (dsBinds binds_2)
-\end{code}
+dsHsBinds :: AutoScc -- scc annotation policy (see below)
+ -> LHsBinds Id
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> DsM [(Id,CoreExpr)] -- Result
+dsHsBinds auto_scc binds rest
+ = foldM (dsLHsBind auto_scc) rest (bagToList binds)
-%==============================================
-\subsubsection{AbsBind case: no overloading}
-%==============================================
+dsLHsBind :: AutoScc
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> LHsBind Id
+ -> DsM [(Id,CoreExpr)] -- Result
+dsLHsBind auto_scc rest (L loc bind)
+ = putSrcSpanDs loc $ dsHsBind auto_scc rest bind
-Special case: no overloading.
-\begin{verbatim}
- x1 = e1
- x2 = e2
-\end{verbatim}
-We abstract each wrt the type variables, giving
-\begin{verbatim}
- x1' = /\tyvars -> e1[x1' tyvars/x1, x2' tyvars/x2]
- x2' = /\tyvars -> e2[x1' tyvars/x1, x2' tyvars/x2]
-\end{verbatim}
-There are some complications.
+dsHsBind :: AutoScc
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> HsBind Id
+ -> DsM [(Id,CoreExpr)] -- Result
-(i) The @val_binds@ might mention variable not in @local_global_prs@.
-In this case we need to make up new polymorphic versions of them.
+dsHsBind auto_scc rest (VarBind var expr)
+ = dsLExpr expr `thenDs` \ core_expr ->
-(ii) Exactly the same applies to any @inst_binds@ which may be
-present. However, here we expect that mostly they will be simple constant
-definitions, which don't mention the type variables at all, so making them
-polymorphic is really overkill. @dsInstBinds@ deals with this case.
+ -- Dictionary bindings are always VarMonoBinds, so
+ -- we only need do this here
+ addDictScc var core_expr `thenDs` \ core_expr' ->
-\begin{code}
-dsBinds (AbsBinds tyvars [] local_global_prs inst_binds val_binds)
- = mapDs mk_poly_private_binder private_binders
- `thenDs` \ poly_private_binders ->
let
- full_local_global_prs = (private_binders `zip` poly_private_binders)
- ++ local_global_prs
- in
- listDs [ mkSatTyApp global tyvar_tys `thenDs` \ app ->
- returnDs (local, app)
- | (local,global) <- full_local_global_prs
- ] `thenDs` \ env ->
-
--- pprTrace "AbsBinds1:" (ppr PprDebug env) $
-
- extendEnvDs env (
-
- dsInstBinds tyvars inst_binds `thenDs` \ (inst_bind_pairs, inst_env) ->
- extendEnvDs inst_env (
-
- dsBind tyvars [] (lookupId full_local_global_prs) inst_bind_pairs val_binds
- ))
- where
- -- "private_binders" is the list of binders in val_binds
- -- which don't appear in the local_global_prs list
- -- These only really show up in stuff produced from compiling
- -- class and instance declarations.
- -- We need to add suitable polymorphic versions of them to the
- -- local_global_prs.
- private_binders = binders `minusList` [local | (local,_) <- local_global_prs]
- binders = collectTypedBinders val_binds
- mk_poly_private_binder id = newSysLocalDs (snd (quantifyTy tyvars (getIdUniType id)))
-
- tyvar_tys = map mkTyVarTy tyvars
-\end{code}
-
-
-%==============================================
-\subsubsection{AbsBind case: overloading}
-%==============================================
-
-If there is overloading we go for the general case.
-
-We want the global identifiers to be abstracted wrt all types and
-dictionaries; and the local identifiers wrt the non-overloaded types.
-That is, we try to avoid global scoping of type abstraction. Example
-
- f :: Eq a => a -> [(a,b)] -> b
- f = ...f...
-
-Here, f is fully polymorphic in b. So we generate
-
- f ab d = let ...dict defns...
- in
- letrec f' b = ...(f' b)...
- in f' b
-
-*Notice* that we don't clone type variables, and *do* make use of
-shadowing. It is possible to do cloning, but it makes the code quite
-a bit more complicated, and the simplifier will clone it all anyway.
-
-Why bother with this gloss? Because it makes it more likely that
-the defn of f' can get floated out, notably if f gets specialised
-to a particular type for a.
-
-\begin{code}
-dsBinds (AbsBinds all_tyvars dicts local_global_prs dict_binds val_binds)
- = -- If there is any non-overloaded polymorphism, make new locals with
- -- appropriate polymorphism
- (if null non_overloaded_tyvars
- then
- -- No non-overloaded polymorphism, so stay with current envt
- returnDs (id, [], [])
- else
- -- Some local, non-overloaded polymorphism
- cloneTyVarsDs non_overloaded_tyvars `thenDs` \ local_tyvars ->
-
- mapDs mk_binder binders `thenDs` \ new_binders ->
- let
- old_new_pairs = binders `zip` new_binders
- in
-
- listDs [ mkSatTyApp new non_ov_tyvar_tys `thenDs` \ app ->
- returnDs (old, app)
- | (old,new) <- old_new_pairs
- ] `thenDs` \ extra_env ->
- let
- local_binds = [CoNonRec old app | (old,app) <- extra_env, old `is_elem` locals]
- is_elem = isIn "dsBinds"
- in
- returnDs (lookupId old_new_pairs, extra_env, local_binds)
- )
- `thenDs` \ (binder_subst_fn, local_env, local_binds) ->
-
--- pprTrace "AbsBinds:all:" (ppAbove (ppr PprDebug local_binds) (ppr PprDebug local_env)) $
-
- extendEnvDs local_env (
-
- dsInstBinds non_overloaded_tyvars dict_binds `thenDs` \ (inst_bind_pairs, inst_env) ->
-
- extendEnvDs inst_env (
-
- dsBind non_overloaded_tyvars [] binder_subst_fn inst_bind_pairs val_binds
- )) `thenDs` \ core_binds ->
-
+ -- Gross hack to prevent inlining into SpecPragmaId rhss
+ -- Consider fromIntegral = fromInteger . toInteger
+ -- spec1 = fromIntegral Int Float
+ -- Even though fromIntegral is small we don't want to inline
+ -- it inside spec1, so that we collect the specialised call
+ -- Solution: make spec1 an INLINE thing.
+ core_expr'' = mkInline (isSpecPragmaId var) core_expr'
+ in
+
+ returnDs ((var, core_expr'') : rest)
+
+dsHsBind auto_scc rest (FunBind (L _ fun) _ matches)
+ = matchWrapper (FunRhs (idName fun)) matches `thenDs` \ (args, body) ->
+ addAutoScc auto_scc (fun, mkLams args body) `thenDs` \ pair ->
+ returnDs (pair : rest)
+
+dsHsBind auto_scc rest (PatBind pat grhss ty)
+ = dsGuarded grhss ty `thenDs` \ body_expr ->
+ mkSelectorBinds pat body_expr `thenDs` \ sel_binds ->
+ mappM (addAutoScc auto_scc) sel_binds `thenDs` \ sel_binds ->
+ returnDs (sel_binds ++ rest)
+
+ -- Common special case: no type or dictionary abstraction
+ -- For the (rare) case when there are some mixed-up
+ -- dictionary bindings (for which a Rec is convenient)
+ -- we reply on the enclosing dsBind to wrap a Rec around.
+dsHsBind auto_scc rest (AbsBinds [] [] exports inlines binds)
+ = dsHsBinds (addSccs auto_scc exports) binds []`thenDs` \ core_prs ->
let
- tuple_rhs = mkCoLetsAny core_binds (
- mkCoLetsAny local_binds (
- mkTupleExpr locals ))
+ core_prs' = addLocalInlines exports inlines core_prs
+ exports' = [(global, Var local) | (_, global, local) <- exports]
in
- mkTupleBind all_tyvars dicts local_global_prs tuple_rhs `thenDs` \ core_bind_prs ->
-
- returnDs [ CoNonRec binder rhs | (binder,rhs) <- core_bind_prs ]
- where
- locals = [local | (local,global) <- local_global_prs]
- non_ov_tyvar_tys = map mkTyVarTy non_overloaded_tyvars
-
- overloaded_tyvars = extractTyVarsFromTys (map getIdUniType dicts)
- non_overloaded_tyvars = all_tyvars `minusList` overloaded_tyvars
-
- binders = collectTypedBinders val_binds
- mk_binder id = newSysLocalDs (snd (quantifyTy non_overloaded_tyvars (getIdUniType id)))
-\end{code}
-
-@mkSatTyApp id tys@ constructs an expression whose value is (id tys).
-However, sometimes id takes more type args than are in tys, and the
-specialiser hates that, so we have to eta expand, to
-(/\ a b -> id tys a b)
-
-\begin{code}
-mkSatTyApp :: Id -- Id to apply to the types
- -> [UniType] -- Types to apply it to
- -> DsM PlainCoreExpr
-
-mkSatTyApp id [] = returnDs (CoVar id)
-
-mkSatTyApp id tys
- | null tyvar_templates
- = returnDs (mkCoTyApps (CoVar id) tys) -- Common case
-
- | otherwise
- = newTyVarsDs (drop (length tys) tyvar_templates) `thenDs` \ tyvars ->
--- pprTrace "mkSatTyApp:" (ppCat [ppr PprDebug id, ppr PprDebug tyvar_templates, ppr PprDebug tyvars, ppr PprDebug theta, ppr PprDebug tau_ty, ppr PprDebug tys]) $
- returnDs (mkCoTyLam tyvars (mkCoTyApps (mkCoTyApps (CoVar id) tys)
- (map mkTyVarTy tyvars)))
- where
- (tyvar_templates, theta, tau_ty) = splitType (getIdUniType id)
-\end{code}
-
-There are several places where we encounter ``inst binds,''
-@(Inst, TypecheckedExpr)@ pairs. Many of these are ``trivial'' binds
-(a var to a var or literal), which we want to substitute away; so we
-return both some desugared bindings {\em and} a substitution
-environment for the subbed-away ones.
-
-These dictionary bindings are non-recursive, and ordered, so that
-later ones may mention earlier ones, but not vice versa.
-
-\begin{code}
-dsInstBinds :: [TyVar] -- Abstract wrt these
- -> [(Inst, TypecheckedExpr)] -- From AbsBinds
- -> DsM ([(Id,PlainCoreExpr)], -- Non-trivial bindings
- [(Id,PlainCoreExpr)]) -- Trivial ones to be substituted away
-
-do_nothing = ([], []) -- out here to avoid dsInstBinds CAF (sigh)
-prel_dicts_cc = preludeDictsCostCentre False{-not dupd-} -- ditto
-
-dsInstBinds tyvars []
- = returnDs do_nothing
-
-dsInstBinds tyvars ((inst, expr@(Var _)) : bs)
- = dsExpr expr `thenDs` ( \ rhs ->
- let -- Need to apply dsExpr to the variable in case it
- -- has a substitution in the current environment
- subst_item = (mkInstId inst, rhs)
+ returnDs (core_prs' ++ exports' ++ rest)
+
+ -- Another common case: one exported variable
+ -- Non-recursive bindings come through this way
+dsHsBind auto_scc rest
+ (AbsBinds all_tyvars dicts exps@[(tyvars, global, local)] inlines binds)
+ = ASSERT( all (`elem` tyvars) all_tyvars )
+ dsHsBinds (addSccs auto_scc exps) binds [] `thenDs` \ core_prs ->
+ let
+ -- Always treat the binds as recursive, because the typechecker
+ -- makes rather mixed-up dictionary bindings
+ core_bind = Rec core_prs
+
+ -- The mkInline does directly what the
+ -- addLocalInlines do in the other cases
+ export' = (global, mkInline (idName global `elemNameSet` inlines) $
+ mkLams tyvars $ mkLams dicts $
+ Let core_bind (Var local))
in
- extendEnvDs [subst_item] (
- dsInstBinds tyvars bs
- ) `thenDs` (\ (binds, subst_env) ->
- returnDs (binds, subst_item : subst_env)
- ))
-
-dsInstBinds tyvars ((inst, expr@(Lit _)) : bs)
- = dsExpr expr `thenDs` ( \ core_lit ->
- let
- subst_item = (mkInstId inst, core_lit)
+ returnDs (export' : rest)
+
+dsHsBind auto_scc rest (AbsBinds all_tyvars dicts exports inlines binds)
+ = dsHsBinds (addSccs auto_scc exports) binds []`thenDs` \ core_prs ->
+ let
+ -- Rec because of mixed-up dictionary bindings
+ core_bind = Rec (addLocalInlines exports inlines core_prs)
+
+ tup_expr = mkTupleExpr locals
+ tup_ty = exprType tup_expr
+ poly_tup_expr = mkLams all_tyvars $ mkLams dicts $
+ Let core_bind tup_expr
+ locals = [local | (_, _, local) <- exports]
+ local_tys = map idType locals
in
- extendEnvDs [subst_item] (
- dsInstBinds tyvars bs
- ) `thenDs` (\ (binds, subst_env) ->
- returnDs (binds, subst_item : subst_env)
- ))
-
-dsInstBinds tyvars ((inst, expr) : bs)
- | null abs_tyvars
- = dsExpr expr `thenDs` \ core_expr ->
- ds_dict_cc core_expr `thenDs` \ dict_expr ->
- dsInstBinds tyvars bs `thenDs` \ (core_rest, subst_env) ->
- returnDs ((mkInstId inst, dict_expr) : core_rest, subst_env)
-
- | otherwise
- = -- Obscure case.
- -- The inst mentions the type vars wrt which we are abstracting,
- -- so we have to invent a new polymorphic version, and substitute
- -- appropriately.
- -- This can occur in, for example:
- -- leftPoll :: [FeedBack a] -> FeedBack a
- -- leftPoll xs = take poll xs
- -- Here there is an instance of take at the type of elts of xs,
- -- as well as the type of poll.
-
- dsExpr expr `thenDs` \ core_expr ->
- ds_dict_cc core_expr `thenDs` \ dict_expr ->
- newSysLocalDs poly_inst_ty `thenDs` \ poly_inst_id ->
+ newSysLocalDs (exprType poly_tup_expr) `thenDs` \ poly_tup_id ->
let
- subst_item = (mkInstId inst, mkCoTyApps (CoVar poly_inst_id) abs_tys)
+ dict_args = map Var dicts
+
+ mk_bind ((tyvars, global, local), n) -- locals !! n == local
+ = -- Need to make fresh locals to bind in the selector, because
+ -- some of the tyvars will be bound to voidTy
+ newSysLocalsDs (map substitute local_tys) `thenDs` \ locals' ->
+ newSysLocalDs (substitute tup_ty) `thenDs` \ tup_id ->
+ returnDs (global, mkLams tyvars $ mkLams dicts $
+ mkTupleSelector locals' (locals' !! n) tup_id $
+ mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args)
+ where
+ mk_ty_arg all_tyvar | all_tyvar `elem` tyvars = mkTyVarTy all_tyvar
+ | otherwise = voidTy
+ ty_args = map mk_ty_arg all_tyvars
+ substitute = substTyWith all_tyvars ty_args
in
- extendEnvDs [subst_item] (
- dsInstBinds tyvars bs
- ) `thenDs` \ (core_rest, subst_env) ->
- returnDs ((poly_inst_id, mkCoTyLam abs_tyvars dict_expr) : core_rest,
- subst_item : subst_env)
- where
- inst_ty = getInstUniType inst
- abs_tyvars = extractTyVarsFromTy inst_ty `intersectLists` tyvars
- abs_tys = map mkTyVarTy abs_tyvars
- (_, poly_inst_ty) = quantifyTy abs_tyvars inst_ty
-
- ------------------------
- -- Wrap a desugared expression in `_scc_ "DICT" <expr>' if
- -- appropriate. Uses "inst"'s type.
-
- ds_dict_cc expr
- = -- if profiling, wrap the dict in "_scc_ DICT <dict>":
- getSwitchCheckerDs `thenDs` \ sw_chkr ->
- let
- doing_profiling = sw_chkr SccProfilingOn
- compiling_prelude = sw_chkr CompilingPrelude
- in
- if not doing_profiling
- || not (isDictTy inst_ty) then -- that's easy: do nothing
- returnDs expr
- else if compiling_prelude then
- returnDs (CoSCC prel_dicts_cc expr)
- else
- getModuleAndGroupDs `thenDs` \ (mod_name, grp_name) ->
- -- ToDo: do -dicts-all flag (mark dict things
- -- with individual CCs)
- let
- dict_cc = mkAllDictsCC mod_name grp_name False{-not dupd-}
- in
- returnDs (CoSCC dict_cc expr)
+ mappM mk_bind (exports `zip` [0..]) `thenDs` \ export_binds ->
+ -- don't scc (auto-)annotate the tuple itself.
+ returnDs ((poly_tup_id, poly_tup_expr) : (export_binds ++ rest))
\end{code}
+
%************************************************************************
%* *
-\subsection[dsBind]{Desugaring a @Bind@}
+\subsection{Adding inline pragmas}
%* *
%************************************************************************
-Like @dsBinds@, @dsBind@ returns a @[PlainCoreBinding]@, but it may be that
-some of the binders are of unboxed type.
-
-For an explanation of the first three args, see @dsMonoBinds@.
-
\begin{code}
-dsBind :: [TyVar] -> [DictVar] -- Abstract wrt these
- -> (Id -> Id) -- Binder substitution
- -> [(Id,PlainCoreExpr)] -- Inst bindings already dealt with
- -> TypecheckedBind
- -> DsM [PlainCoreBinding]
-
-dsBind tyvars dicts binder_subst inst_bind_pairs EmptyBind
- = returnDs [CoNonRec binder rhs | (binder,rhs) <- inst_bind_pairs]
-
-dsBind tyvars dicts binder_subst inst_bind_pairs (NonRecBind monobinds)
- = dsMonoBinds False tyvars dicts binder_subst monobinds `thenDs` ( \ val_bind_pairs ->
- returnDs [CoNonRec binder rhs | (binder,rhs) <- inst_bind_pairs ++ val_bind_pairs] )
-
-dsBind tyvars dicts binder_subst inst_bind_pairs (RecBind monobinds)
- = dsMonoBinds True tyvars dicts binder_subst monobinds `thenDs` ( \ val_bind_pairs ->
- returnDs [CoRec (inst_bind_pairs ++ val_bind_pairs)] )
+mkInline :: Bool -> CoreExpr -> CoreExpr
+mkInline True body = mkInlineMe body
+mkInline False body = body
+
+addLocalInlines :: [(a, Id, Id)] -> NameSet -> [(Id,CoreExpr)] -> [(Id,CoreExpr)]
+addLocalInlines exports inlines pairs
+ = [(bndr, mkInline (bndr `elemVarSet` local_inlines) rhs) | (bndr,rhs) <- pairs]
+ where
+ local_inlines = mkVarSet [l | (_,g,l) <- exports, idName g `elemNameSet` inlines]
\end{code}
%************************************************************************
%* *
-\subsection[dsMonoBinds]{Desugaring a @MonoBinds@}
+\subsection[addAutoScc]{Adding automatic sccs}
%* *
%************************************************************************
-@dsMonoBinds@ transforms @TypecheckedMonoBinds@ into @PlainCoreBinds@.
-In addition to desugaring pattern matching, @dsMonoBinds@ takes
-a list of type variables and dicts, and adds abstractions for these
-to the front of every binding. That requires that the
-binders be altered too (their type has changed,
-so @dsMonoBinds@ also takes a function which maps binders into binders.
-This mapping gives the binder the correct new type.
-
-Remember, there's also a substitution in the monad which maps occurrences
-of these binders into applications of the new binder to suitable type variables
-and dictionaries.
-
\begin{code}
-dsMonoBinds :: Bool -- True <=> recursive binding group
- -> [TyVar] -> [DictVar] -- Abstract wrt these
- -> (Id -> Id) -- Binder substitution
- -> TypecheckedMonoBinds
- -> DsM [(Id,PlainCoreExpr)]
+data AutoScc
+ = TopLevel
+ | TopLevelAddSccs (Id -> Maybe Id)
+ | NoSccs
+
+addSccs :: AutoScc -> [(a,Id,Id)] -> AutoScc
+addSccs auto_scc@(TopLevelAddSccs _) exports = auto_scc
+addSccs NoSccs exports = NoSccs
+addSccs TopLevel exports
+ = TopLevelAddSccs (\id -> case [ exp | (_,exp,loc) <- exports, loc == id ] of
+ (exp:_) | opt_AutoSccsOnAllToplevs ||
+ (isExportedId exp &&
+ opt_AutoSccsOnExportedToplevs)
+ -> Just exp
+ _ -> Nothing)
+
+addAutoScc :: AutoScc -- if needs be, decorate toplevs?
+ -> (Id, CoreExpr)
+ -> DsM (Id, CoreExpr)
+
+addAutoScc (TopLevelAddSccs auto_scc_fn) pair@(bndr, core_expr)
+ | do_auto_scc
+ = getModuleDs `thenDs` \ mod ->
+ returnDs (bndr, mkSCC (mkAutoCC top_bndr mod NotCafCC) core_expr)
+ where do_auto_scc = isJust maybe_auto_scc
+ maybe_auto_scc = auto_scc_fn bndr
+ (Just top_bndr) = maybe_auto_scc
+
+addAutoScc _ pair
+ = returnDs pair
\end{code}
-
-
-%==============================================
-\subsubsection{Structure cases}
-%==============================================
-
-\begin{code}
-dsMonoBinds is_rec tyvars dicts binder_subst EmptyMonoBinds = returnDs []
-
-dsMonoBinds is_rec tyvars dicts binder_subst (AndMonoBinds binds_1 binds_2)
- = andDs (++) (dsMonoBinds is_rec tyvars dicts binder_subst binds_1)
- (dsMonoBinds is_rec tyvars dicts binder_subst binds_2)
-\end{code}
-
-
-%==============================================
-\subsubsection{Simple base cases: function and variable bindings}
-%==============================================
-
-For the simplest bindings, we just heave them in the substitution env:
+If profiling and dealing with a dict binding,
+wrap the dict in @_scc_ DICT <dict>@:
\begin{code}
-{- THESE TWO ARE PLAIN WRONG.
- The extendEnvDs only scopes over the nested call!
- Let the simplifier do this.
-
-dsMonoBinds is_rec tyvars dicts binder_subst (VarMonoBind was_var (Var new_var))
- | not (is_rec || isExported was_var)
- = extendEnvDs [(was_var, CoVar new_var)] (
- returnDs [] )
-
-dsMonoBinds is_rec tyvars dicts binder_subst (VarMonoBind was_var expr@(Lit _))
- | not (isExported was_var)
- = dsExpr expr `thenDs` ( \ core_lit ->
- extendEnvDs [(was_var, core_lit)] (
- returnDs [] ))
--}
+addDictScc var rhs = returnDs rhs
-dsMonoBinds is_rec tyvars dicts binder_subst (VarMonoBind var expr)
- = dsExpr expr `thenDs` ( \ core_expr ->
- returnDs [(binder_subst var, mkCoTyLam tyvars (mkCoLam dicts core_expr))] )
-\end{code}
-
-\begin{code}
-dsMonoBinds is_rec tyvars dicts binder_subst (FunMonoBind fun matches locn)
- = putSrcLocDs locn (
- let
- new_fun = binder_subst fun
- in
- matchWrapper (FunMatch fun) matches (error_msg new_fun) `thenDs` \ (args, body) ->
- returnDs [(new_fun,
- mkCoTyLam tyvars (mkCoLam dicts (mkCoLam args body)))]
- )
- where
- error_msg fun = "%F" -- "incomplete pattern(s) to match in function \""
- ++ (escErrorMsg (ppShow 80 (ppr PprForUser fun))) ++ "\""
-
-dsMonoBinds is_rec tyvars dicts binder_subst (PatMonoBind (VarPat v) grhss_and_binds locn)
- = putSrcLocDs locn (
- dsGuarded grhss_and_binds locn `thenDs` \ body_expr ->
- returnDs [(binder_subst v, mkCoTyLam tyvars (mkCoLam dicts body_expr))]
- )
-\end{code}
-
-%==============================================
-\subsubsection{The general base case}
-%==============================================
-
-Now the general case of a pattern binding. The monomorphism restriction
-should ensure that if there is a non-simple pattern binding in the
-group, then there is no overloading involved, so the dictionaries should
-be empty. (Simple pattern bindings were handled above.)
-First, the paranoia check.
-
-\begin{code}
-dsMonoBinds is_rec tyvars (_:_) binder_subst (PatMonoBind pat grhss_and_binds locn)
- = panic "Non-empty dict list in for pattern binding"
-\end{code}
-
-We handle three cases for the binding
- pat = rhs
-
-\begin{description}
-\item[pat has no binders.]
-Then all this is dead code and we return an empty binding.
-
-\item[pat has exactly one binder, v.]
-Then we can transform to:
-\begin{verbatim}
- v' = /\ tyvars -> case rhs of { pat -> v }
-\end{verbatim}
-where \tr{v'} is gotten by looking up \tr{v} in the \tr{binder_subst}.
-
-\item[pat has more than one binder.]
-Then we transform to:
-\begin{verbatim}
- t = /\ tyvars -> case rhs of { pat -> (v1, ..., vn) }
-
- vi = /\ tyvars -> case (t tyvars) of { (v1, ..., vn) -> vi }
-\end{verbatim}
-\end{description}
-
-\begin{code}
-dsMonoBinds is_rec tyvars [] binder_subst (PatMonoBind pat grhss_and_binds locn)
- = putSrcLocDs locn (
-
- dsGuarded grhss_and_binds locn `thenDs` \ body_expr ->
-
-{- KILLED by Sansom. 95/05
- -- make *sure* there are no primitive types in the pattern
- if any_con_w_prim_arg pat then
- error ( "ERROR: Pattern-bindings cannot involve unboxed/primitive types!\n\t"
- ++ (ppShow 80 (ppr PprForUser pat)) ++ "\n"
- ++ "(We apologise for not reporting this more `cleanly')\n" )
-
- -- Check whether the pattern already is a simple tuple; if so,
- -- we can just use the rhs directly
- else
--}
- mkSelectorBinds tyvars pat
- [(binder, binder_subst binder) | binder <- pat_binders]
- body_expr
- )
- where
- pat_binders = collectTypedPatBinders pat
- -- NB For a simple tuple pattern, these binders
- -- will appear in the right order!
-
-{- UNUSED, post-Sansom:
- any_con_w_prim_arg :: TypecheckedPat -> Bool
-
- any_con_w_prim_arg (WildPat ty) = isPrimType ty
- any_con_w_prim_arg (VarPat v) = isPrimType (getIdUniType v)
- any_con_w_prim_arg (LazyPat pat) = any_con_w_prim_arg pat
- any_con_w_prim_arg (AsPat _ pat) = any_con_w_prim_arg pat
- any_con_w_prim_arg p@(ConPat _ _ args) = any any_con_w_prim_arg args
- any_con_w_prim_arg (ConOpPat a1 _ a2 _) = any any_con_w_prim_arg [a1,a2]
- any_con_w_prim_arg (ListPat _ args) = any any_con_w_prim_arg args
- any_con_w_prim_arg (TuplePat args) = any any_con_w_prim_arg args
- any_con_w_prim_arg (LitPat _ ty) = isPrimType ty
- any_con_w_prim_arg (NPat _ _ _) = False -- be more paranoid?
- any_con_w_prim_arg (NPlusKPat _ _ _ _ _ _) = False -- ditto
-
-#ifdef DPH
- -- Should be more efficient to find type of pid than pats
- any_con_w_prim_arg (ProcessorPat pats _ pat)
- = error "any_con_w_prim_arg:ProcessorPat (DPH)"
-#endif {- Data Parallel Haskell -}
--}
-
-{- OLD ... removed 6 Feb 95
-
- -- we allow it if the constructor has *only one*
- -- argument and that is unboxed, as in
- --
- -- let (I# i#) = ... in ...
- --
- prim_args args
- = let
- no_of_prim_args
- = length [ a | a <- args, isPrimType (typeOfPat a) ]
- in
- if no_of_prim_args == 0 then
- False
- else if no_of_prim_args == 1 && length args == 1 then
- False -- special case we let through
- else
- True
+{- DISABLED for now (need to somehow make up a name for the scc) -- SDM
+ | not ( opt_SccProfilingOn && opt_AutoSccsOnDicts)
+ || not (isDictTy (idType var))
+ = returnDs rhs -- That's easy: do nothing
+ | otherwise
+ = getModuleAndGroupDs `thenDs` \ (mod, grp) ->
+ -- ToDo: do -dicts-all flag (mark dict things with individual CCs)
+ returnDs (Note (SCC (mkAllDictsCC mod grp False)) rhs)
-}
\end{code}
-
-Wild-card patterns could be made acceptable here, but it involves some
-extra work to benefit only rather unusual constructs like
-\begin{verbatim}
- let (_,a,b) = ... in ...
-\end{verbatim}
-Better to extend the whole thing for any irrefutable constructor, at least.
-
-