\section[Desugar]{@deSugar@: the main function}
\begin{code}
-module Desugar ( deSugar ) where
+module Desugar ( deSugar, deSugarExpr ) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_SccProfilingOn )
+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 )
-import TcModule ( TcResults(..) )
+import TcHsSyn ( TypecheckedRuleDecl, TypecheckedHsExpr )
+import TcRnTypes ( TcGblEnv(..), ImportAvails(..) )
+import MkIface ( mkUsageInfo )
import Id ( Id )
import CoreSyn
-import PprCore ( pprIdCoreRule )
+import PprCore ( pprIdRules, pprCoreExpr )
import Subst ( substExpr, mkSubst, mkInScopeSet )
import DsMonad
import DsExpr ( dsExpr )
import DsForeign ( dsForeigns )
import DsExpr () -- Forces DsExpr to be compiled; DsBinds only
-- depends on DsExpr.hi-boot.
-import Module ( Module )
+import Module ( Module, moduleEnvElts )
+import Id ( Id )
+import NameEnv ( lookupNameEnv )
import VarEnv
import VarSet
-import Bag ( isEmptyBag )
-import CoreLint ( beginPass, endPass )
-import ErrUtils ( doIfSet, pprBagOfWarnings )
+import Bag ( isEmptyBag, mapBag )
+import CoreLint ( showPass, endPass )
+import ErrUtils ( doIfSet, dumpIfSet_dyn, pprBagOfWarnings, addShortWarnLocLine )
import Outputable
-import UniqSupply ( UniqSupply )
-import HscTypes ( HomeSymbolTable )
+import qualified Pretty
+import UniqSupply ( mkSplitUniqSupply )
+import Maybes ( orElse )
+import SrcLoc ( SrcLoc )
+import FastString
+import DATA_IOREF ( readIORef )
\end{code}
%************************************************************************
%* *
%************************************************************************
-The only trick here is to get the @DsMonad@ stuff off to a good
-start.
-
\begin{code}
-deSugar :: DynFlags
- -> Module
- -> UniqSupply
- -> HomeSymbolTable
- -> TcResults
- -> IO ([CoreBind], [(Id,CoreRule)], SDoc, SDoc, [CoreBndr])
-
-deSugar dflags mod_name us hst
- (TcResults {tc_env = global_val_env,
- tc_pcs = pcs,
- tc_binds = all_binds,
- tc_rules = rules,
- tc_fords = fo_decls})
- = do
- beginPass dflags "Desugar"
+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 })
+ = do { showPass dflags "Desugar"
+ ; us <- mkSplitUniqSupply 'd'
+ ; usages <- readIORef usage_var
+
-- Do desugaring
- let (result, ds_warns) =
- initDs dflags us (hst,pcs,global_val_env) mod_name
- (dsProgram mod_name all_binds rules fo_decls)
- (ds_binds, ds_rules, _, _, _) = result
+ ; 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)
+
+ -- Display any warnings
+ ; doIfSet (not (isEmptyBag ds_warns))
+ (printErrs warn_doc)
- -- Display any warnings
- doIfSet (not (isEmptyBag ds_warns))
- (printErrs (pprBagOfWarnings ds_warns))
+ -- 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))
+
+ ; 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 = mkUsageInfo hsc_env eps imports 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 mod_guts
+ }
+
+ where
+ dflags = hsc_dflags hsc_env
+ print_unqual = unQualInScope rdr_env
- -- Lint result if necessary
- let do_dump_ds = dopt Opt_D_dump_ds dflags
- endPass dflags "Desugar" do_dump_ds ds_binds
+ -- 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
- doIfSet do_dump_ds (printDump (ppr_ds_rules ds_rules))
+ -- 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)
+ }
- return result
+deSugarExpr :: HscEnv
+ -> PersistentCompilerState
+ -> Module -> GlobalRdrEnv -> TypeEnv
+ -> TypecheckedHsExpr
+ -> IO CoreExpr
+deSugarExpr hsc_env pcs this_mod rdr_env type_env tc_expr
+ = do { showPass dflags "Desugar"
+ ; us <- mkSplitUniqSupply 'd'
-dsProgram mod_name all_binds rules fo_decls
+ -- Do desugaring
+ ; let (core_expr, ds_warns) = initDs dflags us lookup this_mod (dsExpr tc_expr)
+ warn_doc = pprBagOfWarnings (mapBag mk_warn ds_warns)
+
+ -- Display any warnings
+ ; doIfSet (not (isEmptyBag ds_warns))
+ (printErrs warn_doc)
+
+ -- 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 = pprTrace "lookup" (ppr type_env) (
+ 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 mod_name fo_decls `thenDs` \ (fe_binders, foreign_binds, h_code, c_code) ->
+ 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
local_binders = mkVarSet (bindersOfBinds ds_binds)
in
- mapDs (dsRule local_binders) rules `thenDs` \ rules' ->
- returnDs (ds_binds, rules', h_code, c_code, fe_binders)
+ mapDs (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 pprIdCoreRule rules)
+ pprIdRules rules
\end{code}
+
%************************************************************************
%* *
%* Desugaring transformation rules
\begin{code}
dsRule :: IdSet -> TypecheckedRuleDecl -> DsM (Id, CoreRule)
-dsRule in_scope (HsRule name sig_tvs vars lhs rhs loc)
+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 $
ds_lhs all_vars lhs `thenDs` \ (fn, args) ->
dsExpr rhs `thenDs` \ core_rhs ->
- returnDs (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]
+ tpl_vars = [var | RuleBndr var <- vars]
all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars)
ds_lhs all_vars lhs