\section[Desugar]{@deSugar@: the main function}
\begin{code}
-module Desugar ( deSugar ) where
+module Desugar ( deSugar, deSugarExpr ) where
#include "HsVersions.h"
-import CmdLineOpts ( opt_D_dump_ds )
-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(..),
+ Dependencies(..), TypeEnv,
+ unQualInScope )
+import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..),
+ HsExpr(..), HsBinds(..), MonoBinds(..) )
+import TcHsSyn ( TypecheckedRuleDecl, TypecheckedHsExpr )
+import TcRnTypes ( TcGblEnv(..), ImportAvails(..) )
+import MkIface ( mkUsageInfo )
+import Id ( Id )
import CoreSyn
-import Rules ( ProtoCoreRule(..), pprProtoCoreRule )
-import Subst ( substExpr, mkSubst )
+import PprCore ( pprIdRules, pprCoreExpr )
+import Subst ( substExpr, mkSubst, mkInScopeSet )
import DsMonad
import DsExpr ( dsExpr )
import DsBinds ( dsMonoBinds, 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 CmdLineOpts ( opt_SccProfilingOn )
-import CoreLint ( beginPass, endPass )
-import ErrUtils ( doIfSet, pprBagOfWarnings )
+import Bag ( isEmptyBag, mapBag, emptyBag )
+import CoreLint ( showPass, endPass )
+import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings,
+ addShortWarnLocLine, errorsFound )
import Outputable
-import UniqSupply ( UniqSupply )
+import qualified Pretty
+import UniqSupply ( mkSplitUniqSupply )
+import SrcLoc ( SrcLoc )
+import DATA_IOREF ( readIORef )
+import FastString
\end{code}
%************************************************************************
%* *
%************************************************************************
-The only trick here is to get the @DsMonad@ stuff off to a good
-start.
-
\begin{code}
-deSugar :: Module
- -> UniqSupply
- -> TcResults
- -> IO ([CoreBind], [ProtoCoreRule], SDoc, SDoc, [CoreBndr])
-
-deSugar mod_name us (TcResults {tc_env = global_val_env,
- tc_binds = all_binds,
- tc_rules = rules,
- tc_fords = fo_decls})
- = do
- beginPass "Desugar"
+deSugar :: HscEnv -> TcGblEnv -> IO (Maybe ModGuts)
+-- Can modify PCS by faulting in more declarations
+
+deSugar hsc_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,
+ tcg_binds = binds,
+ tcg_fords = fords,
+ tcg_rules = rules })
+ = do { showPass dflags "Desugar"
+
+ -- Do desugaring
+ ; let { is_boot = imp_dep_mods imports }
+ ; (results, warnings) <- initDs hsc_env mod type_env is_boot $
+ dsProgram binds rules fords
+
+ ; 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 emptyNameSet `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
+ 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
+
+
+deSugarExpr :: HscEnv
+ -> Module -> GlobalRdrEnv -> TypeEnv
+ -> TypecheckedHsExpr
+ -> 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 us 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 $
+ dsExpr 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
- endPass "Desugar" opt_D_dump_ds ds_binds
+ -- Dump output
+ ; dumpIfSet_dyn dflags Opt_D_dump_ds "Desugared" (pprCoreExpr core_expr)
- doIfSet opt_D_dump_ds (printDump (ppr_ds_rules ds_rules))
+ ; return core_expr
+ }
+ where
+ dflags = hsc_dflags hsc_env
+ print_unqual = unQualInScope rdr_env
- return result
+ mk_warn :: (SrcLoc,SDoc) -> (SrcLoc, Pretty.Doc)
+ mk_warn (loc,sdoc) = addShortWarnLocLine loc print_unqual sdoc
-dsProgram mod_name all_binds rules fo_decls
+
+dsProgram all_binds rules fo_decls
= dsMonoBinds auto_scc all_binds [] `thenDs` \ core_prs ->
- dsForeigns mod_name fo_decls `thenDs` \ (fi_binds, fe_binds, h_code, c_code) ->
+ dsForeigns fo_decls `thenDs` \ (ds_fords, foreign_binds) ->
let
- ds_binds = fi_binds ++ [Rec core_prs] ++ fe_binds
- fe_binders = bindersOfBinds fe_binds
+ 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#!
+
local_binders = mkVarSet (bindersOfBinds ds_binds)
in
- mapDs (dsRule local_binders) rules `thenDs` \ rules' ->
- returnDs (ds_binds, rules', h_code, c_code, fe_binders)
+ mappM (dsRule local_binders) rules `thenDs` \ ds_rules ->
+ returnDs (ds_binds, ds_rules, ds_fords)
where
auto_scc | opt_SccProfilingOn = TopLevel
| otherwise = NoSccs
ppr_ds_rules [] = empty
ppr_ds_rules rules
= text "" $$ text "-------------- DESUGARED RULES -----------------" $$
- vcat (map pprProtoCoreRule rules)
+ pprIdRules rules
\end{code}
+
%************************************************************************
%* *
%* Desugaring transformation 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)
+dsRule :: IdSet -> TypecheckedRuleDecl -> DsM (Id, CoreRule)
+dsRule in_scope (HsRule name act vars lhs rhs loc)
= putSrcLocDs 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))
+ returnDs (fn, Rule name act tpl_vars args core_rhs)
where
- tpl_vars = sig_tvs ++ [var | RuleBndr var <- vars]
- all_vars = in_scope `unionVarSet` mkVarSet tpl_vars
+ tpl_vars = [var | RuleBndr var <- vars]
+ all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars)
ds_lhs all_vars lhs
= let