#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}
%************************************************************************
%************************************************************************
\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,
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)
; 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
%************************************************************************
\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
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}
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