\begin{code}
module TcRnDriver (
#ifdef GHCI
- mkExportEnv, getModuleContents, tcRnStmt,
+ getModuleContents, tcRnStmt,
tcRnGetInfo, GetInfoResult,
tcRnExpr, tcRnType,
tcRnLookupRdrName,
import TcSimplify ( tcSimplifyTop )
import TcTyClsDecls ( tcTyAndClassDecls )
import LoadIface ( loadOrphanModules )
-import RnNames ( importsFromLocalDecls, rnImports, exportsFromAvail,
+import RnNames ( importsFromLocalDecls, rnImports, rnExports,
reportUnusedNames, reportDeprecations )
import RnEnv ( lookupSrcOcc_maybe )
import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
#ifdef GHCI
import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..), HsBindGroup(..),
- LStmt, LHsExpr, LHsType, mkMatchGroup,
- collectLStmtsBinders, mkSimpleMatch, nlVarPat,
+ LStmt, LHsExpr, LHsType, mkVarBind,
+ collectLStmtsBinders, collectLStmtBinders, nlVarPat,
placeHolderType, noSyntaxExpr )
-import RdrName ( GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
- Provenance(..), ImportSpec(..), globalRdrEnvElts,
- unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv,
- plusGlobalRdrEnv )
+import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
+ unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
import RnSource ( addTcgDUs )
import TcHsSyn ( mkHsLet, zonkTopLExpr, zonkTopBndrs )
import TcHsType ( kcHsType )
import TcMType ( zonkTcType, zonkQuantifiedTyVar )
import TcMatches ( tcStmts, tcDoStmt )
import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
-import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType,
- isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType )
+import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
+ isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
import RnTypes ( rnLHsType )
import Inst ( tcGetInstEnvs )
import TyCon ( tyConName )
import TysWiredIn ( mkListTy, unitTy )
import IdInfo ( GlobalIdDetails(..) )
-import SrcLoc ( interactiveSrcLoc, unLoc )
import Kind ( Kind )
import Var ( globaliseId )
-import Name ( nameOccName, nameModule )
+import Name ( nameOccName, nameModule, isBuiltInSyntax, nameParent_maybe )
import OccName ( occNameUserString, isTcOcc )
import NameEnv ( delListFromNameEnv )
import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
availNames, availName, ModIface(..), icPrintUnqual,
Dependencies(..) )
import BasicTypes ( RecFlag(..), Fixity )
-import ListSetOps ( removeDups )
import Panic ( ghcError, GhcException(..) )
-import SrcLoc ( SrcLoc )
+import SrcLoc ( SrcLoc, unLoc, noSrcSpan )
#endif
import FastString ( mkFastString )
reportDeprecations tcg_env ;
-- Process the export list
- exports <- exportsFromAvail (isJust maybe_mod) export_ies ;
+ exports <- rnExports (isJust maybe_mod) export_ies ;
-- Check whether the entire module is deprecated
-- This happens only once per module
-- We also typecheck any extra binds that came out
-- of the "deriving" process (deriv_binds)
traceTc (text "Tc5") ;
- (tc_val_binds, lcl_env) <- tcTopBinds (val_binds ++ deriv_binds) ;
- setLclTypeEnv lcl_env $ do {
+ (tc_val_binds, tcl_env) <- tcTopBinds (val_binds ++ deriv_binds) ;
+ setLclTypeEnv tcl_env $ do {
-- Second pass over class and instance declarations,
traceTc (text "Tc6") ;
- (tcl_env, inst_binds) <- tcInstDecls2 tycl_decls inst_infos ;
+ (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
showLIE (text "after instDecls2") ;
-- Foreign exports
tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
tcg_rules = tcg_rules tcg_env ++ rules,
tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
- return (tcg_env', lcl_env)
+ return (tcg_env', tcl_env)
}}}}}}
\end{code}
%************************************************************************
\begin{code}
+checkMain :: TcM TcGblEnv
+-- If we are in module Main, check that 'main' is defined.
checkMain
= do { ghci_mode <- getGhciMode ;
tcg_env <- getGblEnv ;
check_main ghci_mode tcg_env main_mod main_fn
- -- If we are in module Main, check that 'main' is defined.
- -- It may be imported from another module!
- --
- --
- -- Blimey: a whole page of code to do this...
| mod /= main_mod
- = return tcg_env
+ = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
+ return tcg_env
| otherwise
= addErrCtxt mainCtxt $
-- Check that 'main' is in scope
-- It might be imported from another module!
; case mb_main of {
- Nothing -> do { complain_no_main
+ Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
+ ; complain_no_main
; return tcg_env } ;
Just main_name -> do
- { let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
+ { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
+ ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
-- :Main.main :: IO () = runMainIO main
; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
failIfErrsM ;
-- The real work is done here
- (bound_ids, tc_expr) <- tcUserStmt rn_stmt ;
+ (bound_ids, tc_expr) <- mkPlan rn_stmt ;
+ zonked_expr <- zonkTopLExpr tc_expr ;
+ zonked_ids <- zonkTopBndrs bound_ids ;
+ -- None of the Ids should be of unboxed type, because we
+ -- cast them all to HValues in the end!
+ mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
+
traceTc (text "tcs 1") ;
let { -- (a) Make all the bound ids "global" ids, now that
-- they're notionally top-level bindings. This is
-- (b) Tidy their types; this is important, because :info may
-- ask to look at them, and :info expects the things it looks
-- up to have tidy types
- global_ids = map globaliseAndTidy bound_ids ;
+ global_ids = map globaliseAndTidy zonked_ids ;
-- Update the interactive context
rn_env = ic_rn_local_env ictxt ;
dumpOptTcRn Opt_D_dump_tc
(vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
- text "Typechecked expr" <+> ppr tc_expr]) ;
+ text "Typechecked expr" <+> ppr zonked_expr]) ;
- returnM (new_ic, bound_names, tc_expr)
+ returnM (new_ic, bound_names, zonked_expr)
}
+ where
+ bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
+ nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
globaliseAndTidy :: Id -> Id
globaliseAndTidy id
\begin{code}
---------------------------
-tcUserStmt :: LStmt Name -> TcM ([Id], LHsExpr Id)
-tcUserStmt (L loc (ExprStmt expr _ _))
- = newUnique `thenM` \ uniq ->
- let
- fresh_it = itName uniq
- the_bind = noLoc $ FunBind (noLoc fresh_it) False
- (mkMatchGroup [mkSimpleMatch [] expr])
- in
- tryTcLIE_ (do { -- Try this if the other fails
- traceTc (text "tcs 1b") ;
- tc_stmts (map (L loc) [
- LetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive],
- ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
- (HsVar thenIOName) placeHolderType
- ]) })
- (do { -- Try this first
- traceTc (text "tcs 1a") ;
- tc_stmts [L loc (BindStmt (nlVarPat fresh_it) expr
- (HsVar bindIOName) noSyntaxExpr) ] })
-
-tcUserStmt stmt = tc_stmts [stmt]
+type PlanResult = ([Id], LHsExpr Id)
+type Plan = TcM PlanResult
+
+runPlans :: [Plan] -> TcM PlanResult
+-- Try the plans in order. If one fails (by raising an exn), try the next.
+-- If one succeeds, take it.
+runPlans [] = panic "runPlans"
+runPlans [p] = p
+runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
+
+--------------------
+mkPlan :: LStmt Name -> TcM PlanResult
+mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
+ = do { uniq <- newUnique -- is treated very specially
+ ; let fresh_it = itName uniq
+ the_bind = mkVarBind noSrcSpan fresh_it expr
+ let_stmt = L loc $ LetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive]
+ bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
+ (HsVar bindIOName) noSyntaxExpr
+ print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
+ (HsVar thenIOName) placeHolderType
+
+ -- The plans are:
+ -- [it <- e; print it] but not if it::()
+ -- [it <- e]
+ -- [let it = e; print it]
+ ; runPlans [ -- Plan A
+ do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
+ ; it_ty <- zonkTcType (idType it_id)
+ ; ifM (isUnitTy it_ty) failM
+ ; return stuff },
+
+ -- Plan B; a naked bind statment
+ tcGhciStmts [bind_stmt],
+
+ -- Plan C; check that the let-binding is typeable all by itself.
+ -- If not, fail; if so, try to print it.
+ -- The two-step process avoids getting two errors: one from
+ -- the expression itself, and one from the 'print it' part
+ do { tcGhciStmts [let_stmt]; tcGhciStmts [let_stmt, print_it] }
+ ]}
+
+mkPlan stmt@(L loc (BindStmt {}))
+ | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
+ = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
+ (HsVar thenIOName) placeHolderType
+ -- The plans are:
+ -- [stmt; print v] but not if v::()
+ -- [stmt]
+ ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
+ ; v_ty <- zonkTcType (idType v_id)
+ ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
+ ; return stuff },
+ tcGhciStmts [stmt]
+ ]}
+
+mkPlan stmt
+ = tcGhciStmts [stmt]
---------------------------
-tc_stmts :: [LStmt Name] -> TcM ([Id], LHsExpr Id)
-tc_stmts stmts
+tcGhciStmts :: [LStmt Name] -> TcM PlanResult
+tcGhciStmts stmts
= do { ioTyCon <- tcLookupTyCon ioTyConName ;
+ ret_id <- tcLookupId returnIOName ; -- return @ IO
let {
+ io_ty = mkTyConApp ioTyCon [] ;
ret_ty = mkListTy unitTy ;
io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
-- then the type checker would instantiate x..z, and we wouldn't
-- get their *polymorphic* values. (And we'd get ambiguity errs
-- if they were overloaded, since they aren't applied to anything.)
- mk_return ret_id ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
- (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
+ mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
+ (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
- (nlHsVar id) ;
-
- io_ty = mkTyConApp ioTyCon []
+ (nlHsVar id)
} ;
-- OK, we're ready to typecheck the stmts
traceTc (text "tcs 2") ;
- ((ids, tc_expr), lie) <- getLIE $ do {
- (tc_stmts, ids) <- tcStmts DoExpr (tcDoStmt io_ty io_ret_ty) stmts $
- do {
- -- Look up the names right in the middle,
- -- where they will all be in scope
- ids <- mappM tcLookupId names ;
- return ids } ;
-
- ret_id <- tcLookupId returnIOName ; -- return @ IO
- return (ids, noLoc (HsDo DoExpr tc_stmts (mk_return ret_id ids) io_ret_ty))
- } ;
-
- -- Simplify the context right here, so that we fail
- -- if there aren't enough instances. Notably, when we see
- -- e
- -- we use recoverTc_ to try it <- e
- -- and then let it = e
- -- It's the simplify step that rejects the first.
- traceTc (text "tcs 3") ;
- const_binds <- tcSimplifyInteractive lie ;
-
- -- Build result expression and zonk it
- let { expr = mkHsLet const_binds tc_expr } ;
- zonked_expr <- zonkTopLExpr expr ;
- zonked_ids <- zonkTopBndrs ids ;
-
- -- None of the Ids should be of unboxed type, because we
- -- cast them all to HValues in the end!
- mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
-
- return (zonked_ids, zonked_expr)
- }
- where
- bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
- nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
+ ((tc_stmts, ids), lie) <- getLIE $
+ tcStmts DoExpr (tcDoStmt io_ty io_ret_ty) stmts $
+ mappM tcLookupId names ;
+ -- Look up the names right in the middle,
+ -- where they will all be in scope
+
+ -- Simplify the context
+ const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
+ -- checkNoErrs ensures that the plan fails if context redn fails
+
+ return (ids, mkHsLet const_binds $
+ noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
+ }
\end{code}
-- Load any orphan-module interfaces,
-- so their instances are visible
ifaceExportNames (mi_exports iface)
-
-mkExportEnv :: HscEnv -> [Module] -- Expose these modules' exports only
- -> IO GlobalRdrEnv
-mkExportEnv hsc_env exports
- = do { mb_envs <- initTcPrintErrors hsc_env iNTERACTIVE $
- mappM getModuleExportRdrEnv exports
- ; case mb_envs of
- Just envs -> return (foldr plusGlobalRdrEnv emptyGlobalRdrEnv envs)
- Nothing -> return emptyGlobalRdrEnv
- -- Some error; initTc will have printed it
- }
-
-getModuleExportRdrEnv :: Module -> TcM GlobalRdrEnv
-getModuleExportRdrEnv mod = do
- names <- tcGetModuleExports mod
- let gres = [ GRE { gre_name = name, gre_prov = vanillaProv mod }
- | name <- nameSetToList names ]
- returnM (mkGlobalRdrEnv gres)
-
-vanillaProv :: Module -> Provenance
--- We're building a GlobalRdrEnv as if the user imported
--- all the specified modules into the global interactive module
-vanillaProv mod = Imported [ImportSpec { is_mod = mod, is_as = mod,
- is_qual = False, is_explicit = False,
- is_loc = srcLocSpan interactiveSrcLoc }]
-
\end{code}
\begin{code}
-- constructor and type class identifiers.
let { rdr_names = dataTcOccs rdr_name } ;
- -- results :: [(Messages, Maybe Name)]
- results <- mapM (tryTc . lookupOccRn) rdr_names ;
+ -- results :: [Either Messages Name]
+ results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
-- The successful lookups will be (Just name)
-- str is the the naked occurrence name
-- after stripping off qualification and parens (+)
str = occNameUserString (nameOccName name)
+
+ ; parent_is_there n
+ | Just p <- nameParent_maybe n = p `elem` good_names
+ | otherwise = False
} ;
- -- For the SrcLoc, the 'thing' has better info than
- -- the 'name' because getting the former forced the
- -- declaration to be loaded into the cache
+ -- For the SrcLoc, the 'thing' has better info than
+ -- the 'name' because getting the former forced the
+ -- declaration to be loaded into the cache
- results <- mapM do_one good_names ;
- return (fst (removeDups cmp results))
+ mapM do_one (filter (not . parent_is_there) good_names)
+ -- Filter out names whose parent is also there
+ -- Good example is '[]', which is both a type and data constructor
+ -- in the same type
}
where
- cmp (_,d1,_,_,_) (_,d2,_,_,_) = ifName d1 `compare` ifName d2
ext_nm = interactiveExtNameFun print_unqual
print_unqual = icPrintUnqual ictxt
plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
= all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
where
- ok name | isExternalName name = print_unqual (nameModule name) (nameOccName name)
- | otherwise = True
+ ok name | isBuiltInSyntax name = True
+ | isExternalName name = print_unqual (nameModule name) (nameOccName name)
+ | otherwise = True
toIfaceDecl :: (Name -> IfaceExtName) -> TyThing -> IfaceDecl
toIfaceDecl ext_nm thing