X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=5880de0eb923ba7e70a865a3b6e4c3443a2f0bd8;hb=4ef18ea237ee070678970dbdd49714014dd9efbf;hp=6e02ef831f7ceaf7c7cf8ade702e4f984fdb1e28;hpb=ce3cab1dc3f3d03d43cf1b8cfc848c1ccaa00a84;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs index 6e02ef8..5880de0 100644 --- a/ghc/compiler/deSugar/Desugar.lhs +++ b/ghc/compiler/deSugar/Desugar.lhs @@ -1,76 +1,251 @@ % -% (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, deSugarExpr ) where #include "HsVersions.h" -import CmdLineOpts ( opt_D_dump_ds ) -import HsSyn ( MonoBinds ) -import TcHsSyn ( TypecheckedMonoBinds, TypecheckedForeignDecl ) - +import CmdLineOpts ( DynFlag(..), dopt, opt_SccProfilingOn ) +import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), ExternalPackageState(..), + PersistentCompilerState(..), Dependencies(..), + lookupType, unQualInScope ) +import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..), + HsExpr(..), HsBinds(..), MonoBinds(..) ) +import TcHsSyn ( TypecheckedRuleDecl, TypecheckedHsExpr ) +import TcRnTypes ( TcGblEnv(..), ImportAvails(..) ) +import MkIface ( mkUsageInfo ) +import Id ( Id ) import CoreSyn -import PprCore ( pprCoreBindings ) +import PprCore ( pprIdRules, pprCoreExpr ) +import Subst ( substExpr, mkSubst, mkInScopeSet ) import DsMonad -import DsBinds ( dsMonoBinds ) +import DsExpr ( dsExpr ) +import DsBinds ( dsMonoBinds, AutoScc(..) ) import DsForeign ( dsForeigns ) -import DsUtils - -import Bag ( isEmptyBag ) -import BasicTypes ( Module ) -import CmdLineOpts ( opt_SccGroup, opt_SccProfilingOn ) -import CoreLift ( liftCoreBindings ) -import CoreLint ( lintCoreBindings ) -import Id ( nullIdEnv, GenId, Id ) -import ErrUtils ( dumpIfSet, doIfSet ) +import DsExpr () -- Forces DsExpr to be compiled; DsBinds only + -- depends on DsExpr.hi-boot. +import Module ( Module, moduleEnvElts ) +import Id ( Id ) +import NameEnv ( lookupNameEnv ) +import VarEnv +import VarSet +import Bag ( isEmptyBag, mapBag ) +import CoreLint ( showPass, endPass ) +import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, addShortWarnLocLine ) import Outputable -import UniqSupply ( splitUniqSupply, UniqSupply ) +import qualified Pretty +import UniqSupply ( mkSplitUniqSupply ) +import SrcLoc ( SrcLoc ) +import FastString +import DATA_IOREF ( readIORef ) \end{code} -The only trick here is to get the @DsMonad@ stuff off to a good -start. +%************************************************************************ +%* * +%* The main function: deSugar +%* * +%************************************************************************ \begin{code} -deSugar :: UniqSupply -- name supply - -> Module -- module name - -> TypecheckedMonoBinds - -> [TypecheckedForeignDecl] - -> IO ([CoreBinding], SDoc, SDoc, SDoc) -- output +deSugar :: HscEnv -> PersistentCompilerState + -> TcGblEnv -> IO ModGuts + +deSugar hsc_env pcs + (TcGblEnv { tcg_mod = mod, + tcg_type_env = type_env, + tcg_usages = usage_var, + tcg_imports = imports, + tcg_exports = exports, + tcg_rdr_env = rdr_env, + tcg_fix_env = fix_env, + tcg_deprecs = deprecs, + tcg_insts = insts, + tcg_binds = binds, + tcg_fords = fords, + tcg_rules = rules }) + = do { showPass dflags "Desugar" + ; us <- mkSplitUniqSupply 'd' + ; usages <- readIORef usage_var + + -- Do desugaring + ; let ((ds_binds, ds_rules, ds_fords), ds_warns) + = initDs dflags us lookup mod + (dsProgram binds rules fords) + + warn_doc = pprBagOfWarnings (mapBag mk_warn ds_warns) -deSugar us mod_name all_binds fo_decls - = let - (us1, us2) = splitUniqSupply us - (us3, us4) = splitUniqSupply us2 + -- Display any warnings + ; doIfSet (not (isEmptyBag ds_warns)) + (printErrs warn_doc) - module_and_group = (mod_name, grp_name) - grp_name = case opt_SccGroup of - Just xx -> _PK_ xx - Nothing -> mod_name -- default: module name + -- Lint result if necessary + ; endPass dflags "Desugar" Opt_D_dump_ds ds_binds - (core_prs, ds_warns) = initDs us1 nullIdEnv module_and_group - (dsMonoBinds opt_SccProfilingOn all_binds []) + -- Dump output + ; doIfSet (dopt Opt_D_dump_ds dflags) + (printDump (ppr_ds_rules ds_rules)) + + ; let + deps = Deps { dep_mods = moduleEnvElts (imp_dep_mods imports), + dep_pkgs = imp_dep_pkgs imports, + dep_orphs = imp_orphs imports } + mod_guts = ModGuts { + mg_module = mod, + mg_exports = exports, + mg_deps = deps, + mg_usages = mkUsageInfo hsc_env eps imports usages, + mg_dir_imps = [m | (m,_) <- moduleEnvElts (imp_mods imports)], + mg_rdr_env = rdr_env, + mg_fix_env = fix_env, + mg_deprecs = deprecs, + mg_types = type_env, + mg_insts = insts, + mg_rules = ds_rules, + mg_binds = ds_binds, + mg_foreign = ds_fords } + + ; return mod_guts + } + + where + dflags = hsc_dflags hsc_env + print_unqual = unQualInScope rdr_env + + -- Desugarer warnings are SDocs; here we + -- add the info about whether or not to print unqualified + mk_warn :: (SrcLoc,SDoc) -> (SrcLoc, Pretty.Doc) + mk_warn (loc, sdoc) = addShortWarnLocLine loc print_unqual sdoc + + -- 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 + eps = pcs_EPS pcs + pte = eps_PTE eps + hpt = hsc_HPT hsc_env + lookup n = case lookupType hpt pte n of { + Just v -> v ; + other -> + case lookupNameEnv type_env n of + Just v -> v ; + other -> pprPanic "Desugar: lookup:" (ppr n) + } + +deSugarExpr :: HscEnv + -> PersistentCompilerState + -> Module -> PrintUnqualified + -> TypecheckedHsExpr + -> IO CoreExpr +deSugarExpr hsc_env pcs 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) + warn_doc = pprBagOfWarnings (mapBag mk_warn ds_warns) + mk_warn :: (SrcLoc,SDoc) -> (SrcLoc, Pretty.Doc) + mk_warn (loc,sdoc) = addShortWarnLocLine loc unqual sdoc - ((fi_binds, fe_binds, hc_code, h_code, c_code), ds_warns2) = - initDs us3 nullIdEnv module_and_group - (dsForeigns fo_decls) + -- Display any warnings + ; doIfSet (not (isEmptyBag ds_warns)) + (printErrs warn_doc) - ds_binds' = liftCoreBindings us4 [Rec (core_prs)] - ds_binds = fi_binds ++ ds_binds' ++ fe_binds + -- Dump output + ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr) + + ; return core_expr + } + where + dflags = hsc_dflags hsc_env + hpt = hsc_HPT hsc_env + pte = eps_PTE (pcs_EPS pcs) + lookup n = case lookupType hpt pte n of + Just v -> v + other -> pprPanic "Desugar: lookup:" (ppr n) + +dsProgram all_binds rules fo_decls + = dsMonoBinds auto_scc all_binds [] `thenDs` \ core_prs -> + dsForeigns fo_decls `thenDs` \ (ds_fords, foreign_binds) -> + 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` \ ds_rules -> + returnDs (ds_binds, ds_rules, ds_fords) + where + auto_scc | opt_SccProfilingOn = TopLevel + | otherwise = NoSccs + +ppr_ds_rules [] = empty +ppr_ds_rules rules + = text "" $$ text "-------------- DESUGARED RULES -----------------" $$ + pprIdRules rules +\end{code} - -- Display any warnings - doIfSet (not (isEmptyBag ds_warns)) - (printErrs (pprDsWarnings ds_warns)) >> - -- Lint result if necessary - lintCoreBindings "Desugarer" False ds_binds >> - -- Dump output - dumpIfSet opt_D_dump_ds "Desugared:" - (pprCoreBindings ds_binds) >> +%************************************************************************ +%* * +%* Desugaring transformation rules +%* * +%************************************************************************ - return (ds_binds, hc_code, h_code, c_code) +\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 + (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 + +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}