X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FdeSugar%2FDesugar.lhs;h=7e284ae9496cc0255185be0f9decd480e61c1978;hp=1415b55c944e2999f2a176b475de7d1d662b6d40;hb=72462499b891d5779c19f3bda03f96e24f9554ae;hpb=7fc749a43b4b6b85d234fa95d4928648259584f4 diff --git a/compiler/deSugar/Desugar.lhs b/compiler/deSugar/Desugar.lhs index 1415b55..7e284ae 100644 --- a/compiler/deSugar/Desugar.lhs +++ b/compiler/deSugar/Desugar.lhs @@ -6,17 +6,8 @@ The Desugarer: turning HsSyn into Core. \begin{code} -{-# OPTIONS -w #-} --- The above warning supression flag is a temporary kludge. --- While working on this module you are encouraged to remove it and fix --- any warnings in the module. See --- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings --- for details - module Desugar ( deSugar, deSugarExpr ) where -#include "HsVersions.h" - import DynFlags import StaticFlags import HscTypes @@ -26,7 +17,6 @@ import MkIface import Id import Name import CoreSyn -import OccurAnal import PprCore import DsMonad import DsExpr @@ -35,23 +25,17 @@ import DsForeign import DsExpr () -- Forces DsExpr to be compiled; DsBinds only -- depends on DsExpr.hi-boot. import Module -import UniqFM -import PackageConfig import RdrName import NameSet -import VarSet import Rules -import CoreLint -import CoreFVs +import CoreMonad ( endPass ) import ErrUtils -import ListSetOps import Outputable import SrcLoc import Maybes import FastString -import Util import Coverage -import IOEnv + import Data.IORef \end{code} @@ -62,7 +46,8 @@ import Data.IORef %************************************************************************ \begin{code} -deSugar :: HscEnv -> ModLocation -> TcGblEnv -> IO (Maybe ModGuts) +-- | Main entry point to the desugarer. +deSugar :: HscEnv -> ModLocation -> TcGblEnv -> IO (Messages, Maybe ModGuts) -- Can modify PCS by faulting in more declarations deSugar hsc_env @@ -72,15 +57,13 @@ deSugar hsc_env 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_inst_env = inst_env, tcg_fam_inst_env = fam_inst_env, - tcg_deprecs = deprecs, + tcg_warns = warns, + tcg_anns = anns, tcg_binds = binds, tcg_fords = fords, tcg_rules = rules, @@ -93,33 +76,36 @@ deSugar hsc_env -- Desugar the program ; let export_set = availsToNameSet exports - ; let auto_scc = mkAutoScc mod export_set + ; let auto_scc = mkAutoScc dflags mod export_set ; let target = hscTarget dflags ; let hpcInfo = emptyHpcInfo other_hpc_info - ; mb_res <- case target of - HscNothing -> return (Just ([], [], NoStubs, hpcInfo, emptyModBreaks)) - _ -> do (binds_cvr,ds_hpc_info, modBreaks) - <- if (opt_Hpc - || target == HscInterpreted) - && (not (isHsBoot hsc_src)) - then addCoverageTicksToBinds dflags mod mod_loc (typeEnvTyCons type_env) binds - else return (binds, hpcInfo, emptyModBreaks) - initDs hsc_env mod rdr_env type_env $ do - { core_prs <- dsTopLHsBinds auto_scc binds_cvr - ; (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, catMaybes ds_rules, ds_fords, ds_hpc_info, modBreaks) - } + ; (msgs, mb_res) + <- case target of + HscNothing -> + return (emptyMessages, + Just ([], [], NoStubs, hpcInfo, emptyModBreaks)) + _ -> do + (binds_cvr,ds_hpc_info, modBreaks) + <- if (opt_Hpc + || target == HscInterpreted) + && (not (isHsBoot hsc_src)) + then addCoverageTicksToBinds dflags mod mod_loc (typeEnvTyCons type_env) binds + else return (binds, hpcInfo, emptyModBreaks) + initDs hsc_env mod rdr_env type_env $ do + core_prs <- dsTopLHsBinds auto_scc binds_cvr + (ds_fords, foreign_prs) <- dsForeigns fords + let all_prs = foreign_prs ++ core_prs + ds_rules <- mapM dsRule rules + return (all_prs, catMaybes ds_rules, ds_fords, ds_hpc_info, modBreaks) + ; case mb_res of { - Nothing -> return Nothing ; + Nothing -> return (msgs, Nothing) ; Just (all_prs, ds_rules, ds_fords,ds_hpc_info, modBreaks) -> do { -- Add export flags to bindings keep_alive <- readIORef keep_var ; let final_prs = addExportFlags target export_set - keep_alive all_prs ds_rules + keep_alive all_prs 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# @@ -128,55 +114,26 @@ deSugar hsc_env -- 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 ds_rules -- 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 - pkgs | th_used = insertList thPackageId (imp_dep_pkgs imports) - | otherwise = imp_dep_pkgs imports - - dep_mods = eltsUFM (delFromUFM (imp_dep_mods imports) (moduleName 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 = moduleNameFS (moduleName m1) - <= moduleNameFS (moduleName m2) - le_dep_mod :: (ModuleName, IsBootInterface) -> (ModuleName, IsBootInterface) -> Bool - le_dep_mod (m1,_) (m2,_) = moduleNameFS m1 <= moduleNameFS m2 - - deps = Deps { dep_mods = sortLe le_dep_mod dep_mods, - dep_pkgs = sortLe (<=) pkgs, - dep_orphs = sortLe le_mod (imp_orphs imports), - dep_finsts = sortLe le_mod (imp_finsts imports) } - -- sort to get into canonical order - - mod_guts = ModGuts { + ; used_names <- mkUsedNames tcg_env + ; deps <- mkDependencies tcg_env + + ; let 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_used_names = used_names, + mg_dir_imps = imp_mods imports, mg_rdr_env = rdr_env, mg_fix_env = fix_env, - mg_deprecs = deprecs, + mg_warns = warns, + mg_anns = anns, mg_types = type_env, mg_insts = insts, mg_fam_insts = fam_insts, @@ -189,43 +146,47 @@ deSugar hsc_env mg_modBreaks = modBreaks, mg_vect_info = noVectInfo } - ; return (Just mod_guts) + ; return (msgs, Just mod_guts) }}} -mkAutoScc :: Module -> NameSet -> AutoScc -mkAutoScc mod exports +mkAutoScc :: DynFlags -> Module -> NameSet -> AutoScc +mkAutoScc dflags mod exports | not opt_SccProfilingOn -- No profiling = NoSccs - | opt_AutoSccsOnAllToplevs -- Add auto-scc on all top-level things - = AddSccs mod (\id -> True) - | opt_AutoSccsOnExportedToplevs -- Only on exported things + -- Add auto-scc on all top-level things + | dopt Opt_AutoSccsOnAllToplevs dflags + = AddSccs mod (\id -> not $ isDerivedOccName $ getOccName id) + -- See #1641. This is pretty yucky, but I can't see a better way + -- to identify compiler-generated Ids, and at least this should + -- catch them all. + -- Only on exported things + | dopt Opt_AutoSccsOnExportedToplevs dflags = AddSccs mod (\id -> idName id `elemNameSet` exports) | otherwise = NoSccs - deSugarExpr :: HscEnv -> Module -> GlobalRdrEnv -> TypeEnv -> LHsExpr Id - -> IO (Maybe CoreExpr) + -> IO (Messages, Maybe CoreExpr) -- Prints its own errors; returns Nothing if error occurred -deSugarExpr hsc_env this_mod rdr_env type_env tc_expr - = do { let dflags = hsc_dflags hsc_env - ; showPass dflags "Desugar" +deSugarExpr hsc_env this_mod rdr_env type_env tc_expr = do + let dflags = hsc_dflags hsc_env + showPass dflags "Desugar" - -- Do desugaring - ; mb_core_expr <- initDs hsc_env this_mod rdr_env type_env $ - dsLExpr tc_expr + -- Do desugaring + (msgs, mb_core_expr) <- initDs hsc_env this_mod rdr_env type_env $ + dsLExpr tc_expr - ; case mb_core_expr of { - Nothing -> return Nothing ; - Just expr -> do { + case mb_core_expr of + Nothing -> return (msgs, Nothing) + Just expr -> do - -- Dump output - dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr expr) + -- Dump output + dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr expr) - ; return (Just expr) } } } + return (msgs, Just expr) -- addExportFlags -- Set the no-discard flag if either @@ -243,24 +204,17 @@ deSugarExpr hsc_env this_mod rdr_env type_env tc_expr -- it's just because the type checker is rather busy already and -- I didn't want to pass in yet another mapping. -addExportFlags target exports keep_alive prs rules +addExportFlags :: HscTarget -> NameSet -> NameSet -> [(Id, t)] + -> [(Id, t)] +addExportFlags target exports keep_alive prs = [(add_export bndr, rhs) | (bndr,rhs) <- prs] where add_export bndr | dont_discard bndr = setIdExported bndr | otherwise = bndr - orph_rhs_fvs = unionVarSets [ ruleRhsFreeVars rule - | rule <- rules, - not (isLocalRule rule) ] - -- A non-local rule keeps alive the free vars of its right-hand side. - -- (A "non-local" is one whose head function is not locally defined.) - -- Local 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 @@ -275,9 +229,10 @@ addExportFlags target exports keep_alive prs rules is_exported | target == HscInterpreted = isExternalName | otherwise = (`elemNameSet` exports) +ppr_ds_rules :: [CoreRule] -> SDoc ppr_ds_rules [] = empty ppr_ds_rules rules - = text "" $$ text "-------------- DESUGARED RULES -----------------" $$ + = blankLine $$ text "-------------- DESUGARED RULES -----------------" $$ pprRules rules \end{code} @@ -290,32 +245,41 @@ ppr_ds_rules rules %************************************************************************ \begin{code} -dsRule :: Module -> IdSet -> LRuleDecl Id -> DsM (Maybe CoreRule) -dsRule mod in_scope (L loc (HsRule name act vars lhs tv_lhs rhs fv_rhs)) +dsRule :: LRuleDecl Id -> DsM (Maybe CoreRule) +dsRule (L loc (HsRule name act vars lhs _tv_lhs rhs _fv_rhs)) = putSrcSpanDs loc $ - do { let bndrs = [var | RuleBndr (L _ var) <- vars] - ; lhs' <- dsLExpr lhs + do { let bndrs' = [var | RuleBndr (L _ var) <- vars] + + ; lhs' <- unsetOptM Opt_EnableRewriteRules $ + dsLExpr lhs -- Note [Desugaring RULE lhss] + ; rhs' <- dsLExpr rhs - ; case decomposeRuleLhs (occurAnalyseExpr lhs') of { - Nothing -> do { warnDs msg; return Nothing } ; - Just (fn_id, args) -> do - -- Substitute the dict bindings eagerly, -- and take the body apart into a (f args) form + ; case decomposeRuleLhs (mkLams bndrs' lhs') of { + Nothing -> do { warnDs msg; return Nothing } ; + Just (bndrs, fn_id, args) -> do + { let local_rule = isLocalId fn_id -- NB: isLocalId is False of implicit Ids. This is good becuase -- we don't want to attach rules to the bindings of implicit Ids, -- because they don't show up in the bindings until just before code gen - fn_name = idName fn_id - - rule = Rule { ru_name = name, ru_fn = fn_name, ru_act = act, - ru_bndrs = bndrs, ru_args = args, ru_rhs = rhs', - ru_rough = roughTopNames args, - ru_local = local_rule } + fn_name = idName fn_id + rule = mkRule local_rule name act fn_name bndrs args rhs' ; return (Just rule) } } } where - msg = hang (ptext SLIT("RULE left-hand side too complicated to desugar; ignored")) + msg = hang (ptext (sLit "RULE left-hand side too complicated to desugar; ignored")) 2 (ppr lhs) \end{code} + +Note [Desugaring RULE left hand sides] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +For the LHS of a RULE we do *not* want to desugar + [x] to build (\cn. x `c` n) +We want to leave explicit lists simply as chains +of cons's. We can achieve that slightly indirectly by +switching off EnableRewriteRules. + +That keeps the desugaring of list comprehensions simple too.