X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=2deb3433b34d9f648b94e5a4b8e3401a1e741809;hb=3721dd37a707d2aacb5cac814410a78096e28a2c;hp=5090a9e872f84823bddca000f938b576073d4369;hpb=9bb6b6d0fbca6c82040027fab9859c9fcbc1ef7e;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs index 5090a9e..2deb343 100644 --- a/ghc/compiler/deSugar/Desugar.lhs +++ b/ghc/compiler/deSugar/Desugar.lhs @@ -4,33 +4,45 @@ \section[Desugar]{@deSugar@: the main function} \begin{code} -module Desugar ( deSugar ) where +module Desugar ( deSugar, deSugarExpr ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_SccProfilingOn ) -import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..), - HsExpr(..), HsBinds(..), MonoBinds(..) ) -import TcHsSyn ( TypecheckedRuleDecl ) -import TcModule ( TcResults(..) ) +import CmdLineOpts ( DynFlag(..), dopt, opt_SccProfilingOn ) +import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), GhciMode(..), + Dependencies(..), TypeEnv, + unQualInScope, availsToNameSet ) +import HsSyn ( RuleDecl(..), RuleBndr(..), HsExpr(..), LHsExpr, + HsBindGroup(..), LRuleDecl, HsBind(..) ) +import TcRnTypes ( TcGblEnv(..), ImportAvails(..) ) +import MkIface ( mkUsageInfo ) +import Id ( Id, setIdLocalExported, idName ) +import Name ( Name, isExternalName ) import CoreSyn -import Rules ( ProtoCoreRule(..), pprProtoCoreRule ) +import PprCore ( pprIdRules, pprCoreExpr ) import Subst ( substExpr, mkSubst, mkInScopeSet ) import DsMonad -import DsExpr ( dsExpr ) -import DsBinds ( dsMonoBinds, AutoScc(..) ) +import DsExpr ( dsLExpr ) +import DsBinds ( dsHsBinds, AutoScc(..) ) import DsForeign ( dsForeigns ) import DsExpr () -- Forces DsExpr to be compiled; DsBinds only -- depends on DsExpr.hi-boot. -import Module ( Module ) +import Module ( Module, moduleEnvElts, emptyModuleEnv ) +import Id ( Id ) +import RdrName ( GlobalRdrEnv ) +import NameSet import VarEnv import VarSet -import Bag ( isEmptyBag ) -import CoreLint ( beginPass, endPass ) -import ErrUtils ( doIfSet, pprBagOfWarnings ) +import Bag ( isEmptyBag, mapBag, emptyBag, bagToList ) +import CoreLint ( showPass, endPass ) +import CoreFVs ( ruleRhsFreeVars ) +import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, + mkWarnMsg, errorsFound, WarnMsg ) import Outputable -import UniqSupply ( UniqSupply ) -import HscTypes ( HomeSymbolTable ) +import UniqSupply ( mkSplitUniqSupply ) +import SrcLoc ( Located(..), SrcSpan, unLoc ) +import DATA_IOREF ( readIORef ) +import FastString \end{code} %************************************************************************ @@ -39,69 +51,198 @@ import HscTypes ( HomeSymbolTable ) %* * %************************************************************************ -The only trick here is to get the @DsMonad@ stuff off to a good -start. - \begin{code} -deSugar :: DynFlags - -> Module - -> UniqSupply - -> HomeSymbolTable - -> TcResults - -> IO ([CoreBind], [ProtoCoreRule], SDoc, SDoc, [CoreBndr]) - -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" +deSugar :: HscEnv -> TcGblEnv -> IO (Maybe ModGuts) +-- Can modify PCS by faulting in more declarations + +deSugar hsc_env + tcg_env@(TcGblEnv { tcg_mod = mod, + tcg_type_env = type_env, + tcg_imports = imports, + tcg_exports = exports, + tcg_dus = dus, + tcg_inst_uses = dfun_uses_var, + tcg_rdr_env = rdr_env, + tcg_fix_env = fix_env, + tcg_deprecs = deprecs, + tcg_insts = insts }) + = do { showPass dflags "Desugar" + + -- Do desugaring + ; let { is_boot = imp_dep_mods imports } + ; (results, warnings) <- initDs hsc_env mod type_env is_boot $ + dsProgram ghci_mode tcg_env + + ; let { (ds_binds, ds_rules, ds_fords) = results + ; warns = mapBag mk_warn warnings + ; warn_doc = pprBagOfWarnings warns } + + -- Display any warnings + ; doIfSet (not (isEmptyBag warnings)) + (printErrs warn_doc) + + -- If warnings are considered errors, leave. + ; if errorsFound dflags (warns, emptyBag) + then return Nothing + else do + + -- 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)) + + ; dfun_uses <- readIORef dfun_uses_var -- What dfuns are used + ; let used_names = allUses dus `unionNameSets` dfun_uses + ; usages <- mkUsageInfo hsc_env imports used_names + ; 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 = 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 (Just mod_guts) + }} + + where + dflags = hsc_dflags hsc_env + ghci_mode = hsc_mode 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 :: (SrcSpan,SDoc) -> WarnMsg + mk_warn (loc, sdoc) = mkWarnMsg loc print_unqual sdoc + + +deSugarExpr :: HscEnv + -> Module -> GlobalRdrEnv -> TypeEnv + -> LHsExpr Id + -> IO CoreExpr +deSugarExpr hsc_env this_mod rdr_env type_env tc_expr + = do { showPass dflags "Desugar" + ; us <- mkSplitUniqSupply 'd' + -- 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 + ; let { is_boot = emptyModuleEnv } -- Assume no hi-boot files when + -- doing stuff from the command line + ; (core_expr, ds_warns) <- initDs hsc_env this_mod type_env is_boot $ + dsLExpr tc_expr - -- Display any warnings - doIfSet (not (isEmptyBag ds_warns)) - (printErrs (pprBagOfWarnings ds_warns)) + -- Display any warnings + -- Note: if -Werror is used, we don't signal an error here. + ; doIfSet (not (isEmptyBag ds_warns)) + (printErrs (pprBagOfWarnings (mapBag mk_warn ds_warns))) - -- Lint result if necessary - let do_dump_ds = dopt Opt_D_dump_ds dflags - endPass dflags "Desugar" do_dump_ds ds_binds + -- Dump output + ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr) + + ; return core_expr + } + where + dflags = hsc_dflags hsc_env + print_unqual = unQualInScope rdr_env - doIfSet do_dump_ds (printDump (ppr_ds_rules ds_rules)) + mk_warn :: (SrcSpan,SDoc) -> WarnMsg + mk_warn (loc,sdoc) = mkWarnMsg loc print_unqual sdoc - return result -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) -> +dsProgram ghci_mode (TcGblEnv { tcg_exports = exports, + tcg_keep = keep_alive, + tcg_binds = binds, + tcg_fords = fords, + tcg_rules = rules }) + = dsHsBinds auto_scc binds [] `thenDs` \ core_prs -> + dsForeigns fords `thenDs` \ (ds_fords, foreign_prs) -> let - ds_binds = [Rec (foreign_binds ++ core_prs)] + all_prs = foreign_prs ++ core_prs + local_bndrs = mkVarSet (map fst all_prs) + in + mappM (dsRule local_bndrs) rules `thenDs` \ ds_rules -> + let + final_prs = addExportFlags ghci_mode exports keep_alive + local_bndrs all_prs ds_rules + ds_binds = [Rec final_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) + returnDs (ds_binds, ds_rules, ds_fords) where auto_scc | opt_SccProfilingOn = TopLevel | otherwise = NoSccs +-- addExportFlags +-- Set the no-discard flag if either +-- a) the Id is exported +-- b) it's mentioned in the RHS of an orphan rule +-- c) it's in the keep-alive set +-- +-- It means that the binding won't be discarded EVEN if the binding +-- ends up being trivial (v = w) -- the simplifier would usually just +-- substitute w for v throughout, but we don't apply the substitution to +-- the rules (maybe we should?), so this substitution would make the rule +-- bogus. + +-- You might wonder why exported Ids aren't already marked as such; +-- it's just because the type checker is rather busy already and +-- I didn't want to pass in yet another mapping. + +addExportFlags ghci_mode exports keep_alive bndrs prs rules + = [(add_export bndr, rhs) | (bndr,rhs) <- prs] + where + add_export bndr | dont_discard bndr = setIdLocalExported bndr + | otherwise = bndr + + orph_rhs_fvs = unionVarSets [ ruleRhsFreeVars rule + | (id, rule) <- rules, + not (id `elemVarSet` bndrs) ] + -- An orphan rule must keep alive the free vars + -- of its right-hand side. + -- Non-orphan rules are attached to the Id (bndr_with_rules above) + -- and that keeps the rhs free vars alive + + dont_discard bndr = is_exported name + || name `elemNameSet` keep_alive + || bndr `elemVarSet` orph_rhs_fvs + where + name = idName bndr + + -- In interactive mode, we don't want to discard any top-level + -- entities at all (eg. do not inline them away during + -- simplification), and retain them all in the TypeEnv so they are + -- available from the command line. + -- + -- isExternalName separates the user-defined top-level names from those + -- introduced by the type checker. + is_exported :: Name -> Bool + is_exported | ghci_mode == Interactive = isExternalName + | otherwise = (`elemNameSet` exports) + ppr_ds_rules [] = empty ppr_ds_rules rules = text "" $$ text "-------------- DESUGARED RULES -----------------" $$ - vcat (map pprProtoCoreRule rules) + pprIdRules rules \end{code} + %************************************************************************ %* * %* Desugaring transformation rules @@ -109,28 +250,25 @@ ppr_ds_rules rules %************************************************************************ \begin{code} -dsRule :: IdSet -> TypecheckedRuleDecl -> DsM ProtoCoreRule -dsRule in_scope (IfaceRuleOut fn rule) - = returnDs (ProtoCoreRule False {- non-local -} fn rule) - -dsRule in_scope (HsRule name sig_tvs vars lhs rhs loc) - = putSrcLocDs loc $ +dsRule :: IdSet -> LRuleDecl Id -> DsM (Id, CoreRule) +dsRule in_scope (L loc (HsRule name act vars lhs rhs)) + = putSrcSpanDs loc $ ds_lhs all_vars lhs `thenDs` \ (fn, args) -> - dsExpr rhs `thenDs` \ core_rhs -> - returnDs (ProtoCoreRule True {- local -} fn - (Rule name tpl_vars args core_rhs)) + dsLExpr rhs `thenDs` \ core_rhs -> + returnDs (fn, Rule name act tpl_vars args core_rhs) where - tpl_vars = sig_tvs ++ [var | RuleBndr var <- vars] - all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars) + tpl_vars = [var | RuleBndr (L _ var) <- vars] + all_vars = mkInScopeSet (extendVarSetList in_scope 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) + (dict_binds, body) = + case unLoc lhs of + (HsLet [HsBindGroup dict_binds _ _] body) -> (dict_binds, body) + other -> (emptyBag, lhs) in - ds_dict_binds dict_binds `thenDs` \ dict_binds' -> - dsExpr body `thenDs` \ body' -> + mappM ds_dict_bind (bagToList dict_binds) `thenDs` \ dict_binds' -> + dsLExpr body `thenDs` \ body' -> -- Substitute the dict bindings eagerly, -- and take the body apart into a (f args) form @@ -152,10 +290,7 @@ ds_lhs all_vars 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')] +ds_dict_bind (L _ (VarBind id rhs)) = + dsLExpr rhs `thenDs` \ rhs' -> + returnDs (id,rhs') \end{code}