X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=39f3978d02b84c11aaccf5b82f96c69f6a6c265e;hb=ef5b4b146aa172d8ac10f39b5eb3d7a0f948d8f1;hp=f06cd26c0f6626b8ebac19b6e1ce72385e3575bc;hpb=11047b5e250ae889a642429a8d39ec0991cd26da;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs index f06cd26..39f3978 100644 --- a/ghc/compiler/deSugar/Desugar.lhs +++ b/ghc/compiler/deSugar/Desugar.lhs @@ -8,40 +8,43 @@ module Desugar ( deSugar, deSugarExpr ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlag(..), dopt, opt_SccProfilingOn ) -import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), ExternalPackageState(..), - PersistentCompilerState(..), Dependencies(..), TypeEnv, GlobalRdrEnv, - lookupType, unQualInScope ) -import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..), - HsExpr(..), HsBinds(..), MonoBinds(..) ) -import TcHsSyn ( TypecheckedRuleDecl, TypecheckedHsExpr ) +import CmdLineOpts ( DynFlag(..), DynFlags(..), dopt, opt_SccProfilingOn ) +import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), GhciMode(..), + Dependencies(..), TypeEnv, IsBootInterface, unQualInScope ) +import HsSyn ( RuleDecl(..), RuleBndr(..), HsExpr(..), LHsExpr, + HsBindGroup(..), LRuleDecl, HsBind(..) ) import TcRnTypes ( TcGblEnv(..), ImportAvails(..) ) import MkIface ( mkUsageInfo ) -import Id ( Id ) +import Id ( Id, setIdLocalExported, idName, idIsFrom, isLocalId ) +import Name ( Name, isExternalName ) import CoreSyn import PprCore ( pprIdRules, pprCoreExpr ) -import Subst ( substExpr, mkSubst, mkInScopeSet ) +import Subst ( SubstResult(..), substExpr, mkSubst, extendIdSubstList ) 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, moduleEnvElts ) +import Module ( Module, moduleEnvElts, delModuleEnv, moduleFS ) import Id ( Id ) -import NameEnv ( lookupNameEnv ) +import RdrName ( GlobalRdrEnv ) +import NameSet import VarEnv import VarSet -import Bag ( isEmptyBag, mapBag ) +import Bag ( Bag, isEmptyBag, mapBag, emptyBag, bagToList ) import CoreLint ( showPass, endPass ) -import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, addShortWarnLocLine ) +import CoreFVs ( ruleRhsFreeVars ) +import Packages ( PackageState(thPackageId) ) +import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, + mkWarnMsg, errorsFound, WarnMsg ) +import ListSetOps ( insertList ) import Outputable -import qualified Pretty import UniqSupply ( mkSplitUniqSupply ) -import Maybes ( orElse ) -import SrcLoc ( SrcLoc ) -import FastString +import SrcLoc ( Located(..), SrcSpan, unLoc ) import DATA_IOREF ( readIORef ) +import FastString +import Util ( sortLe ) \end{code} %************************************************************************ @@ -51,54 +54,102 @@ import DATA_IOREF ( readIORef ) %************************************************************************ \begin{code} -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 }) +deSugar :: HscEnv -> TcGblEnv -> IO (Bag WarnMsg, 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_th_used = th_var, + tcg_keep = keep_var, + tcg_rdr_env = rdr_env, + tcg_fix_env = fix_env, + tcg_deprecs = deprecs, + tcg_binds = binds, + tcg_fords = fords, + tcg_rules = rules, + tcg_insts = insts }) = 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 the program + ; ((all_prs, ds_rules, ds_fords), warns) + <- initDs hsc_env mod rdr_env type_env $ do + { core_prs <- dsHsBinds auto_scc binds [] + ; (ds_fords, foreign_prs) <- dsForeigns fords + ; let all_prs = foreign_prs ++ core_prs + local_bndrs = mkVarSet (map fst all_prs) + ; ds_rules <- mappM (dsRule mod local_bndrs) rules + ; return (all_prs, ds_rules, ds_fords) } - -- Display any warnings - ; doIfSet (not (isEmptyBag ds_warns)) - (printErrs warn_doc) + + + -- If warnings are considered errors, leave. + ; if errorsFound dflags (warns, emptyBag) + then return (warns, Nothing) + else do + + { -- Add export flags to bindings + keep_alive <- readIORef keep_var + ; let final_prs = addExportFlags ghci_mode exports keep_alive + 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#! -- Lint result if necessary - ; endPass dflags "Desugar" Opt_D_dump_ds ds_binds + ; 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 + ; th_used <- readIORef th_var -- Whether TH is used + ; let used_names = allUses dus `unionNameSets` dfun_uses + thPackage = thPackageId (pkgState dflags) + pkgs | Just th_id <- thPackage, th_used + = insertList th_id (imp_dep_pkgs imports) + | otherwise + = imp_dep_pkgs imports + + dep_mods = moduleEnvElts (delModuleEnv (imp_dep_mods imports) mod) + -- M.hi-boot can be in the imp_dep_mods, but we must remove + -- it before recording the modules on which this one depends! + -- (We want to retain M.hi-boot in imp_dep_mods so that + -- loadHiBootInterface can see if M's direct imports depend + -- on M.hi-boot, and hence that we should do the hi-boot consistency + -- check.) + + dir_imp_mods = imp_mods imports + + ; usages <- mkUsageInfo hsc_env dir_imp_mods dep_mods used_names + ; let - deps = Deps { dep_mods = moduleEnvElts (imp_dep_mods imports), - dep_pkgs = imp_dep_pkgs imports, - dep_orphs = imp_orphs imports } + -- Modules don't compare lexicographically usually, + -- but we want them to do so here. + le_mod :: Module -> Module -> Bool + le_mod m1 m2 = moduleFS m1 <= moduleFS m2 + le_dep_mod :: (Module, IsBootInterface) -> (Module, IsBootInterface) -> Bool + le_dep_mod (m1,_) (m2,_) = m1 `le_mod` m2 + + deps = Deps { dep_mods = sortLe le_dep_mod dep_mods, + dep_pkgs = sortLe (<=) pkgs, + dep_orphs = sortLe le_mod (imp_orphs imports) } + -- sort to get into canonical order + 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_usages = usages, + mg_dir_imps = [m | (m,_,_) <- moduleEnvElts dir_imp_mods], mg_rdr_env = rdr_env, mg_fix_env = fix_env, mg_deprecs = deprecs, @@ -108,49 +159,31 @@ deSugar hsc_env pcs mg_binds = ds_binds, mg_foreign = ds_fords } - ; return mod_guts - } + ; return (warns, Just 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) - } + ghci_mode = hsc_mode hsc_env + auto_scc | opt_SccProfilingOn = TopLevel + | otherwise = NoSccs deSugarExpr :: HscEnv - -> PersistentCompilerState -> Module -> GlobalRdrEnv -> TypeEnv - -> TypecheckedHsExpr + -> LHsExpr Id -> IO CoreExpr -deSugarExpr hsc_env pcs mod_name rdr_env type_env tc_expr +deSugarExpr hsc_env this_mod rdr_env type_env 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) + ; (core_expr, ds_warns) <- initDs hsc_env this_mod rdr_env type_env $ + dsLExpr tc_expr - -- Display any warnings + -- Display any warnings + -- Note: if -Werror is used, we don't signal an error here. ; doIfSet (not (isEmptyBag ds_warns)) - (printErrs warn_doc) + (printErrs (pprBagOfWarnings ds_warns)) -- Dump output ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr) @@ -158,37 +191,58 @@ deSugarExpr hsc_env pcs mod_name rdr_env type_env tc_expr ; return core_expr } where - dflags = hsc_dflags hsc_env - hpt = hsc_HPT hsc_env - pte = eps_PTE (pcs_EPS pcs) - lookup n = lookupNameEnv type_env n `orElse` -- Look in the type env of the - -- current module first - lookupType hpt pte n `orElse` -- Then other modules - pprPanic "Desugar: lookup:" (ppr n) - - mk_warn :: (SrcLoc,SDoc) -> (SrcLoc, Pretty.Doc) - mk_warn (loc,sdoc) = addShortWarnLocLine loc print_unqual sdoc - - print_unqual = unQualInScope rdr_env - -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#! + dflags = hsc_dflags hsc_env - local_binders = mkVarSet (bindersOfBinds ds_binds) - in - mapDs (dsRule local_binders) rules `thenDs` \ ds_rules -> - returnDs (ds_binds, ds_rules, ds_fords) + +-- 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 prs rules + = [(add_export bndr, rhs) | (bndr,rhs) <- prs] where - auto_scc | opt_SccProfilingOn = TopLevel - | otherwise = NoSccs + add_export bndr + | isLocalId bndr && dont_discard bndr = setIdLocalExported bndr + -- The isLocalId check is to avoid fiddling with + -- locally-defined Ids like data cons and class ops + -- which are "born" as GlobalIds + | otherwise = bndr + + orph_rhs_fvs = unionVarSets [ ruleRhsFreeVars rule + | IdCoreRule _ is_orphan_rule rule <- rules, + is_orphan_rule ] + -- An orphan rule keeps alive the free vars of its right-hand side. + -- Non-orphan rules are (later, after gentle simplification) + -- attached to the Id 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 @@ -205,37 +259,36 @@ ppr_ds_rules rules %************************************************************************ \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 $ +dsRule :: Module -> IdSet -> LRuleDecl Id -> DsM IdCoreRule +dsRule mod 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 (fn, Rule name act tpl_vars args core_rhs) + dsLExpr rhs `thenDs` \ core_rhs -> + returnDs (IdCoreRule fn (is_orphan 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) + tpl_vars = [var | RuleBndr (L _ var) <- vars] + all_vars = mkInScopeSet (extendVarSetList in_scope tpl_vars) + is_orphan id = not (idIsFrom mod id) + -- NB we can't use isLocalId in the orphan test, + -- because isLocalId isn't true of class methods 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 let - subst_env = mkSubstEnv [id | (id,rhs) <- dict_binds'] - [ContEx subst_env rhs | (id,rhs) <- dict_binds'] + subst = extendIdSubstList (mkSubst all_vars) pairs + pairs = [(id, ContEx subst 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 @@ -247,10 +300,7 @@ 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}