%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[Desugar]{@deSugar@: the main function}
\begin{code}
-module Desugar ( deSugar, pprDsWarnings ) where
+module Desugar ( deSugar ) where
#include "HsVersions.h"
-import CmdLineOpts ( opt_D_dump_ds )
-import HsSyn ( HsBinds, HsExpr, MonoBinds
- )
-import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr
- )
+import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_SccProfilingOn )
+import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..),
+ HsExpr(..), HsBinds(..), MonoBinds(..) )
+import TcHsSyn ( TypecheckedRuleDecl )
+import TcModule ( TcResults(..) )
import CoreSyn
-import PprCore ( pprCoreBindings )
-import Name ( isExported )
+import PprCore ( pprIdCoreRule )
+import Subst ( substExpr, mkSubst, mkInScopeSet )
import DsMonad
-import DsBinds ( dsMonoBinds )
-import DsUtils
-
-import Bag ( unionBags, isEmptyBag )
-import BasicTypes ( Module, RecFlag(..) )
-import CmdLineOpts ( opt_DoCoreLinting, opt_SccGroup, opt_SccProfilingOn )
-import CostCentre ( IsCafCC(..), mkAutoCC )
-import CoreLift ( liftCoreBindings )
-import CoreLint ( lintCoreBindings )
-import Id ( nullIdEnv, mkIdEnv, idType,
- DictVar, GenId, Id )
-import ErrUtils ( dumpIfSet, doIfSet )
+import DsExpr ( dsExpr )
+import DsBinds ( dsMonoBinds, AutoScc(..) )
+import DsForeign ( dsForeigns )
+import DsExpr () -- Forces DsExpr to be compiled; DsBinds only
+ -- depends on DsExpr.hi-boot.
+import Module ( Module )
+import VarEnv
+import VarSet
+import Bag ( isEmptyBag )
+import CoreLint ( beginPass, endPass )
+import ErrUtils ( doIfSet, pprBagOfWarnings )
import Outputable
-import UniqSupply ( splitUniqSupply, UniqSupply )
+import UniqSupply ( UniqSupply )
+import HscTypes ( HomeSymbolTable )
\end{code}
+%************************************************************************
+%* *
+%* The main function: deSugar
+%* *
+%************************************************************************
+
The only trick here is to get the @DsMonad@ stuff off to a good
start.
\begin{code}
-deSugar :: UniqSupply -- name supply
- -> Module -- module name
- -> TypecheckedMonoBinds
- -> IO [CoreBinding] -- output
+deSugar :: DynFlags
+ -> Module
+ -> UniqSupply
+ -> HomeSymbolTable
+ -> TcResults
+ -> IO ([CoreBind], [(Id,CoreRule)], SDoc, SDoc, [CoreBndr])
-deSugar us mod_name all_binds
- = let
- (us1, us2) = splitUniqSupply us
+deSugar dflags mod_name us hst
+ (TcResults {tc_env = global_val_env,
+ tc_pcs = pcs,
+ tc_binds = all_binds,
+ tc_rules = rules,
+ tc_fords = fo_decls})
+ = do
+ beginPass dflags "Desugar"
+ -- Do desugaring
+ let (result, ds_warns) =
+ initDs dflags us (hst,pcs,global_val_env) mod_name
+ (dsProgram mod_name all_binds rules fo_decls)
+ (ds_binds, ds_rules, _, _, _) = result
+
+ -- Display any warnings
+ doIfSet (not (isEmptyBag ds_warns))
+ (printErrs (pprBagOfWarnings ds_warns))
+
+ -- Lint result if necessary
+ let do_dump_ds = dopt Opt_D_dump_ds dflags
+ endPass dflags "Desugar" do_dump_ds ds_binds
- module_and_group = (mod_name, grp_name)
- grp_name = case opt_SccGroup of
- Just xx -> _PK_ xx
- Nothing -> mod_name -- default: module name
+ doIfSet do_dump_ds (printDump (ppr_ds_rules ds_rules))
- (core_prs, ds_warns) = initDs us1 nullIdEnv module_and_group
- (dsMonoBinds opt_SccProfilingOn all_binds [])
+ return result
- ds_binds = liftCoreBindings us2 [Rec core_prs]
+dsProgram mod_name all_binds rules fo_decls
+ = dsMonoBinds auto_scc all_binds [] `thenDs` \ core_prs ->
+ dsForeigns mod_name fo_decls `thenDs` \ (fe_binders, foreign_binds, h_code, c_code) ->
+ let
+ ds_binds = [Rec (foreign_binds ++ core_prs)]
+ -- Notice that we put the whole lot in a big Rec, even the foreign binds
+ -- When compiling PrelFloat, which defines data Float = F# Float#
+ -- we want F# to be in scope in the foreign marshalling code!
+ -- You might think it doesn't matter, but the simplifier brings all top-level
+ -- things into the in-scope set before simplifying; so we get no unfolding for F#!
+
+ local_binders = mkVarSet (bindersOfBinds ds_binds)
in
+ mapDs (dsRule local_binders) rules `thenDs` \ rules' ->
+ returnDs (ds_binds, rules', h_code, c_code, fe_binders)
+ where
+ auto_scc | opt_SccProfilingOn = TopLevel
+ | otherwise = NoSccs
+
+ppr_ds_rules [] = empty
+ppr_ds_rules rules
+ = text "" $$ text "-------------- DESUGARED RULES -----------------" $$
+ vcat (map pprIdCoreRule rules)
+\end{code}
- -- Display any warnings
- doIfSet (not (isEmptyBag ds_warns))
- (printErrs (pprDsWarnings ds_warns)) >>
- -- Lint result if necessary
- lintCoreBindings "Desugarer" False ds_binds >>
+%************************************************************************
+%* *
+%* Desugaring transformation rules
+%* *
+%************************************************************************
- -- Dump output
- dumpIfSet opt_D_dump_ds "Desugared:"
- (pprCoreBindings ds_binds) >>
+\begin{code}
+dsRule :: IdSet -> TypecheckedRuleDecl -> DsM (Id, CoreRule)
+dsRule in_scope (HsRule name sig_tvs vars lhs rhs loc)
+ = putSrcLocDs loc $
+ ds_lhs all_vars lhs `thenDs` \ (fn, args) ->
+ dsExpr rhs `thenDs` \ core_rhs ->
+ returnDs (fn, Rule name tpl_vars args core_rhs)
+ where
+ tpl_vars = sig_tvs ++ [var | RuleBndr var <- vars]
+ all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars)
+
+ds_lhs all_vars lhs
+ = let
+ (dict_binds, body) = case lhs of
+ (HsLet (MonoBind dict_binds _ _) body) -> (dict_binds, body)
+ other -> (EmptyMonoBinds, lhs)
+ in
+ ds_dict_binds dict_binds `thenDs` \ dict_binds' ->
+ dsExpr body `thenDs` \ body' ->
+
+ -- Substitute the dict bindings eagerly,
+ -- and take the body apart into a (f args) form
+ let
+ subst_env = mkSubstEnv [id | (id,rhs) <- dict_binds']
+ [ContEx subst_env rhs | (id,rhs) <- dict_binds']
+ -- Note recursion here... substitution won't terminate
+ -- if there is genuine recursion... which there isn't
+
+ subst = mkSubst all_vars subst_env
+ body'' = substExpr subst body'
+ in
+
+ -- Now unpack the resulting body
+ let
+ pair = case collectArgs body'' of
+ (Var fn, args) -> (fn, args)
+ other -> pprPanic "dsRule" (ppr lhs)
+ in
+ returnDs pair
- return ds_binds
+ds_dict_binds EmptyMonoBinds = returnDs []
+ds_dict_binds (AndMonoBinds b1 b2) = ds_dict_binds b1 `thenDs` \ env1 ->
+ ds_dict_binds b2 `thenDs` \ env2 ->
+ returnDs (env1 ++ env2)
+ds_dict_binds (VarMonoBind id rhs) = dsExpr rhs `thenDs` \ rhs' ->
+ returnDs [(id,rhs')]
\end{code}
projects / ghc-hetmet.git / blobdiff