X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=261f31989d5f47d8d2ef4193d12c979ee28279f2;hb=0299e1a135c5805e09ed8e2271b3b17fc8a04869;hp=1e290757065696a00fdb1779583d8da5e9dffb52;hpb=7d61cb61daa5e433a0cb85b34b7f0c58b2f961ff;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs index 1e29075..261f319 100644 --- a/ghc/compiler/deSugar/Desugar.lhs +++ b/ghc/compiler/deSugar/Desugar.lhs @@ -1,96 +1,212 @@ % -% (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} -#include "HsVersions.h" - -module Desugar ( deSugar, DsMatchContext, pprDsWarnings ) where +module Desugar ( deSugar, deSugarExpr ) where -import Ubiq{-uitous-} +#include "HsVersions.h" -import HsSyn ( HsBinds, HsExpr ) -import TcHsSyn ( TypecheckedHsBinds(..), TypecheckedHsExpr(..) ) +import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_SccProfilingOn ) +import HscTypes ( ModDetails(..) ) +import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..), + HsExpr(..), HsBinds(..), MonoBinds(..) ) +import TcHsSyn ( TypecheckedRuleDecl, TypecheckedHsExpr ) +import TcModule ( TcResults(..) ) +import Id ( Id ) import CoreSyn - +import PprCore ( pprIdCoreRule, pprCoreExpr ) +import Subst ( substExpr, mkSubst, mkInScopeSet ) import DsMonad -import DsBinds ( dsBinds, dsInstBinds ) -import DsUtils - -import Bag ( unionBags ) -import CmdLineOpts ( opt_DoCoreLinting ) -import CoreLift ( liftCoreBindings ) -import CoreLint ( lintCoreBindings ) -import Id ( nullIdEnv, mkIdEnv ) -import PprStyle ( PprStyle(..) ) -import UniqSupply ( splitUniqSupply ) +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 Id ( Id ) +import NameEnv ( lookupNameEnv ) +import VarEnv +import VarSet +import Bag ( isEmptyBag ) +import CoreLint ( showPass, endPass ) +import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings ) +import Outputable +import UniqSupply ( mkSplitUniqSupply ) +import HscTypes ( HomeSymbolTable, PersistentCompilerState(..), TyThing(..), lookupType, ) \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 - -> FAST_STRING -- module name +deSugar :: DynFlags + -> PersistentCompilerState -> HomeSymbolTable + -> Module -> PrintUnqualified + -> TcResults + -> IO (ModDetails, (SDoc, SDoc, [FAST_STRING], [CoreBndr])) + +deSugar dflags pcs hst mod_name unqual + (TcResults {tc_env = type_env, + tc_binds = all_binds, + tc_insts = insts, + tc_rules = rules, + tc_fords = fo_decls}) + = do { showPass dflags "Desugar" + ; us <- mkSplitUniqSupply 'd' + + -- Do desugaring + ; let (ds_result, ds_warns) = initDs dflags us lookup mod_name + (dsProgram mod_name all_binds rules fo_decls) + + (ds_binds, ds_rules, foreign_stuff) = ds_result + + mod_details = ModDetails { md_types = type_env, + md_insts = insts, + md_rules = ds_rules, + md_binds = ds_binds } + + -- Display any warnings + ; doIfSet (not (isEmptyBag ds_warns)) + (printErrs unqual (pprBagOfWarnings ds_warns)) + + -- Lint result if necessary + ; endPass dflags "Desugar" Opt_D_dump_ds ds_binds + + -- Dump output + ; doIfSet (dopt Opt_D_dump_ds dflags) + (printDump (ppr_ds_rules ds_rules)) + + ; return (mod_details, foreign_stuff) + } + + where + -- The lookup function passed to initDs is used for well-known Ids, + -- such as fold, build, cons etc, so the chances are + -- it'll be found in the package symbol table. That's + -- why we don't merge all these tables + pte = pcs_PTE pcs + lookup n = case lookupType hst pte n of { + Just (AnId v) -> v ; + other -> + case lookupNameEnv type_env n of + Just (AnId v) -> v ; + other -> pprPanic "Desugar: lookup:" (ppr n) + } + +deSugarExpr :: DynFlags + -> PersistentCompilerState -> HomeSymbolTable + -> Module -> PrintUnqualified + -> TypecheckedHsExpr + -> IO CoreExpr +deSugarExpr dflags pcs hst mod_name unqual tc_expr + = do { showPass dflags "Desugar" + ; us <- mkSplitUniqSupply 'd' + + -- Do desugaring + ; let (core_expr, ds_warns) = initDs dflags us lookup mod_name (dsExpr tc_expr) + + -- Display any warnings + ; doIfSet (not (isEmptyBag ds_warns)) + (printErrs unqual (pprBagOfWarnings ds_warns)) + + -- Dump output + ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr) + + ; return core_expr + } + where + pte = pcs_PTE pcs + lookup n = case lookupType hst pte n of + Just (AnId v) -> v + other -> pprPanic "Desugar: lookup:" (ppr n) + +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, headers) -> + 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, headers, 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} - -> (TypecheckedHsBinds, -- input: recsel, class, instance, and value - TypecheckedHsBinds, -- bindings; see "tcModule" (which produces - TypecheckedHsBinds, -- them) - TypecheckedHsBinds, - [(Id, TypecheckedHsExpr)]) --- ToDo: handling of const_inst thingies is certainly WRONG *************************** - -> ([CoreBinding], -- output - Bag DsMatchContext) -- Shadowing complaints +%************************************************************************ +%* * +%* Desugaring transformation rules +%* * +%************************************************************************ -deSugar us mod_name (recsel_binds, clas_binds, inst_binds, val_binds, const_inst_pairs) +\begin{code} +dsRule :: IdSet -> TypecheckedRuleDecl -> DsM (Id, CoreRule) +dsRule in_scope (IfaceRuleOut fun rule) -- Built-in rules come this way + = returnDs (fun, rule) + +dsRule in_scope (HsRule name act vars lhs rhs loc) + = putSrcLocDs loc $ + ds_lhs all_vars lhs `thenDs` \ (fn, args) -> + dsExpr rhs `thenDs` \ core_rhs -> + returnDs (fn, Rule name act tpl_vars args core_rhs) + where + tpl_vars = [var | RuleBndr var <- vars] + all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars) + +ds_lhs all_vars lhs = let - (us0, us0a) = splitUniqSupply us - (us1, us1a) = splitUniqSupply us0a - (us2, us2a) = splitUniqSupply us1a - (us3, us3a) = splitUniqSupply us2a - (us4, us5) = splitUniqSupply us3a - - ((core_const_prs, consts_pairs), shadows1) - = initDs us0 nullIdEnv mod_name (dsInstBinds [] const_inst_pairs) - - consts_env = mkIdEnv consts_pairs - - (core_clas_binds, shadows2) - = initDs us1 consts_env mod_name (dsBinds clas_binds) - core_clas_prs = pairsFromCoreBinds core_clas_binds - - (core_inst_binds, shadows3) - = initDs us2 consts_env mod_name (dsBinds inst_binds) - core_inst_prs = pairsFromCoreBinds core_inst_binds - - (core_val_binds, shadows4) - = initDs us3 consts_env mod_name (dsBinds val_binds) - core_val_pairs = pairsFromCoreBinds core_val_binds - - (core_recsel_binds, shadows5) - = initDs us4 consts_env mod_name (dsBinds recsel_binds) - core_recsel_prs = pairsFromCoreBinds core_recsel_binds - - final_binds - = if (null core_clas_prs && null core_inst_prs - && null core_recsel_prs {-???dont know???-} && null core_const_prs) then - -- we don't have to make the whole thing recursive - core_clas_binds ++ core_val_binds - - else -- gotta make it recursive (sigh) - [Rec (core_clas_prs ++ core_inst_prs - ++ core_const_prs ++ core_val_pairs ++ core_recsel_prs)] - - lift_final_binds = liftCoreBindings us5 final_binds - - really_final_binds = if opt_DoCoreLinting - then lintCoreBindings PprDebug "Desugarer" False lift_final_binds - else lift_final_binds - - shadows = shadows1 `unionBags` shadows2 `unionBags` - shadows3 `unionBags` shadows4 `unionBags` shadows5 + (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 - (really_final_binds, shadows) + returnDs pair + +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}