X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=be26463f4959c0dab7b962103898893845b43f02;hb=508a505e9853984bfdaa3ad855ae3fcbc6d31787;hp=1a49ec32c4851366cee9b20d30edd2c3ab6cf686;hpb=6858f7c15fcf9efe9e6fdf22de34d0791b0f0c08;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs index 1a49ec3..be26463 100644 --- a/ghc/compiler/deSugar/Desugar.lhs +++ b/ghc/compiler/deSugar/Desugar.lhs @@ -8,33 +8,44 @@ module Desugar ( deSugar, deSugarExpr ) where #include "HsVersions.h" -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 CmdLineOpts ( DynFlag(..), DynFlags(..), dopt, opt_SccProfilingOn ) +import DriverPhases ( isHsBoot ) +import HscTypes ( ModGuts(..), ModGuts, HscEnv(..), GhciMode(..), + Dependencies(..), TypeEnv, IsBootInterface ) +import HsSyn ( RuleDecl(..), RuleBndr(..), HsExpr(..), LHsExpr, + HsBindGroup(..), LRuleDecl, HsBind(..) ) +import TcRnTypes ( TcGblEnv(..), ImportAvails(..) ) +import MkIface ( mkUsageInfo ) +import Id ( Id, setIdExported, idName, idIsFrom ) +import Name ( Name, isExternalName ) import CoreSyn -import PprCore ( pprIdCoreRule, pprCoreExpr ) -import Subst ( substExpr, mkSubst, mkInScopeSet ) +import PprCore ( pprIdRules, pprCoreExpr ) +import CoreSubst ( substExpr, mkSubst ) 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, delModuleEnv, moduleFS ) import Id ( Id ) -import NameEnv ( lookupNameEnv ) +import RdrName ( GlobalRdrEnv ) +import NameSet import VarEnv import VarSet -import Bag ( isEmptyBag ) +import Bag ( Bag, isEmptyBag, emptyBag, bagToList ) import CoreLint ( showPass, endPass ) -import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings ) +import CoreFVs ( ruleRhsFreeVars ) +import Packages ( PackageState(thPackageId), PackageIdH(..) ) +import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, + errorsFound, WarnMsg ) +import ListSetOps ( insertList ) import Outputable import UniqSupply ( mkSplitUniqSupply ) -import HscTypes ( HomeSymbolTable, PersistentCompilerState(..), TyThing(..), lookupType, ) +import SrcLoc ( Located(..), unLoc ) +import DATA_IOREF ( readIORef ) +import FastString +import Util ( sortLe ) \end{code} %************************************************************************ @@ -43,79 +54,139 @@ import HscTypes ( HomeSymbolTable, PersistentCompilerState(..), TyThing(..), lo %* * %************************************************************************ -The only trick here is to get the @DsMonad@ stuff off to a good -start. - \begin{code} -deSugar :: DynFlags - -> PersistentCompilerState -> HomeSymbolTable - -> Module -> PrintUnqualified - -> TcResults - -> IO (ModDetails, (SDoc, SDoc, [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}) +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_src = hsc_src, + 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' - -- Do desugaring - ; let (ds_result, ds_warns) = initDs dflags us lookup mod_name - (dsProgram mod_name all_binds rules fo_decls) + -- 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) } - (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)) + + -- 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)) + (printDump (ppr_ds_rules ds_rules)) - ; return (mod_details, foreign_stuff) - } + ; 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 | ExtPackage 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 + -- 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_boot = isHsBoot hsc_src, + mg_exports = exports, + mg_deps = deps, + 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, + mg_types = type_env, + mg_insts = insts, + mg_rules = ds_rules, + mg_binds = ds_binds, + mg_foreign = ds_fords } + + ; return (warns, Just mod_guts) + }} 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 + dflags = hsc_dflags hsc_env + ghci_mode = hsc_mode hsc_env + auto_scc | opt_SccProfilingOn = TopLevel + | otherwise = NoSccs + +deSugarExpr :: HscEnv + -> Module -> GlobalRdrEnv -> TypeEnv + -> LHsExpr Id -> IO CoreExpr -deSugarExpr dflags pcs hst mod_name unqual 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) + ; (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 unqual (pprBagOfWarnings ds_warns)) + (printErrs (pprBagOfWarnings ds_warns)) -- Dump output ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr) @@ -123,37 +194,64 @@ deSugarExpr dflags pcs hst mod_name unqual tc_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) -> - 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` \ rules' -> - returnDs (ds_binds, rules', (h_code, c_code, fe_binders)) + +-- 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 + | dont_discard bndr = setIdExported bndr + | 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 = text "" $$ text "-------------- DESUGARED RULES -----------------" $$ - vcat (map pprIdCoreRule rules) + pprIdRules rules \end{code} + %************************************************************************ %* * %* Desugaring transformation rules @@ -161,37 +259,37 @@ 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 sig_tvs 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 = 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) + 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 = mkSubst all_vars emptyVarEnv (mkVarEnv id_pairs) + id_pairs = [(id, substExpr 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 @@ -203,10 +301,7 @@ 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}