X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcRnDriver.lhs;h=57da566c96add3e43a3a1ad0ba460b0c36647815;hb=56dda711a0f410674c107259a52a36dff9a93a17;hp=227d5720b075e3d2f5df9d772febe747c2c21ef1;hpb=20e1c6cc426dcc864c7fc5710b1b5aa25453061c;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcRnDriver.lhs b/ghc/compiler/typecheck/TcRnDriver.lhs index 227d572..57da566 100644 --- a/ghc/compiler/typecheck/TcRnDriver.lhs +++ b/ghc/compiler/typecheck/TcRnDriver.lhs @@ -6,7 +6,8 @@ \begin{code} module TcRnDriver ( #ifdef GHCI - mkExportEnv, getModuleContents, tcRnStmt, tcRnThing, tcRnExpr, + mkExportEnv, getModuleContents, tcRnStmt, + tcRnGetInfo, tcRnExpr, tcRnType, #endif tcRnModule, tcTopSrcDecls, @@ -21,7 +22,8 @@ import {-# SOURCE #-} TcSplice ( tcSpliceDecls ) import CmdLineOpts ( DynFlag(..), opt_PprStyle_Debug, dopt ) import DriverState ( v_MainModIs, v_MainFunIs ) -import HsSyn +import HsSyn ( HsModule(..), HsExtCore(..), HsGroup(..), LHsDecl, SpliceDecl(..), HsBind(..), + nlHsApp, nlHsVar, pprLHsBinds ) import RdrHsSyn ( findSplice ) import PrelNames ( runIOName, rootMainName, mAIN_Name, @@ -31,15 +33,15 @@ import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv, import TcHsSyn ( zonkTopDecls ) import TcExpr ( tcInferRho ) import TcRnMonad -import TcType ( tidyTopType ) +import TcType ( tidyTopType, isUnLiftedType ) import Inst ( showLIE ) import TcBinds ( tcTopBinds ) import TcDefaults ( tcDefaults ) -import TcEnv ( tcExtendGlobalValEnv, tcLookupGlobal ) +import TcEnv ( tcExtendGlobalValEnv ) import TcRules ( tcRules ) import TcForeign ( tcForeignImports, tcForeignExports ) import TcInstDcls ( tcInstDecls1, tcInstDecls2 ) -import TcIface ( tcExtCoreBindings ) +import TcIface ( tcExtCoreBindings, loadImportedInsts ) import TcSimplify ( tcSimplifyTop ) import TcTyClsDecls ( tcTyAndClassDecls ) import LoadIface ( loadOrphanModules ) @@ -49,68 +51,76 @@ import RnEnv ( lookupSrcOcc_maybe ) import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec ) import PprCore ( pprIdRules, pprCoreBindings ) import CoreSyn ( IdCoreRule, bindersOfBinds ) -import ErrUtils ( mkDumpDoc, showPass ) +import ErrUtils ( Messages, mkDumpDoc, showPass ) import Id ( mkExportedLocalId, isLocalId, idName, idType ) import Var ( Var ) import Module ( mkHomeModule, mkModuleName, moduleName, moduleEnvElts ) import OccName ( mkVarOcc ) -import Name ( Name, isExternalName, getSrcLoc, getOccName ) +import Name ( Name, isExternalName, getSrcLoc, getOccName, nameSrcLoc ) import NameSet import TyCon ( tyConHasGenerics ) -import SrcLoc ( srcLocSpan, Located(..), noLoc ) +import SrcLoc ( SrcLoc, srcLocSpan, Located(..), noLoc ) import Outputable -import HscTypes ( ModGuts(..), HscEnv(..), - GhciMode(..), noDependencies, +import HscTypes ( ModGuts(..), HscEnv(..), ExternalPackageState( eps_is_boot ), + GhciMode(..), isOneShot, Dependencies(..), noDependencies, Deprecs( NoDeprecs ), plusDeprecs, - GenAvailInfo(Avail), availsToNameSet, availName, - ForeignStubs(NoStubs), TypeEnv, typeEnvTyCons, - extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, + ForeignStubs(NoStubs), TypeEnv, + extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, emptyFixityEnv ) #ifdef GHCI -import HsSyn ( HsStmtContext(..), - Stmt(..), - collectStmtsBinders, mkSimpleMatch, placeHolderType ) +import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..), HsBindGroup(..), + LStmt, LHsExpr, LHsType, + collectStmtsBinders, mkSimpleMatch, placeHolderType, + nlLetStmt, nlExprStmt, nlBindStmt, nlResultStmt, nlVarPat ) import RdrName ( GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), Provenance(..), ImportSpec(..), lookupLocalRdrEnv, extendLocalRdrEnv ) import RnSource ( addTcgDUs ) import TcHsSyn ( mkHsLet, zonkTopLExpr, zonkTopBndrs ) +import TcHsType ( kcHsType ) import TcExpr ( tcCheckRho ) import TcMType ( zonkTcType ) import TcMatches ( tcStmtsAndThen, TcStmtCtxt(..) ) import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer ) -import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType ) -import TcEnv ( tcLookupTyCon, tcLookupId ) -import TyCon ( DataConDetails(..) ) -import Inst ( tcStdSyntaxName ) +import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, tyClsNamesOfDFunHead ) +import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal ) +import RnTypes ( rnLHsType ) +import Inst ( tcStdSyntaxName, tcGetInstEnvs ) +import InstEnv ( DFunId, classInstances, instEnvElts ) import RnExpr ( rnStmts, rnLExpr ) import RnNames ( exportsToAvails ) import LoadIface ( loadSrcInterface ) -import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..), IfaceExtName(..), - tyThingToIfaceDecl ) +import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..), + IfaceExtName(..), IfaceConDecls(..), IfaceInst(..), + tyThingToIfaceDecl, dfunToIfaceInst ) import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn ) -import Id ( Id, isImplicitId ) +import Id ( Id, isImplicitId, globalIdDetails ) +import FieldLabel ( fieldLabelTyCon ) import MkId ( unsafeCoerceId ) +import DataCon ( dataConTyCon ) +import TyCon ( tyConName ) import TysWiredIn ( mkListTy, unitTy ) import IdInfo ( GlobalIdDetails(..) ) import SrcLoc ( interactiveSrcLoc, unLoc ) +import Kind ( Kind ) import Var ( globaliseId ) import Name ( nameOccName, nameModuleName ) import NameEnv ( delListFromNameEnv ) import PrelNames ( iNTERACTIVE, ioTyConName, printName, monadNames, itName, returnIOName ) import Module ( ModuleName, lookupModuleEnvByName ) -import HscTypes ( InteractiveContext(..), - HomeModInfo(..), typeEnvElts, - TyThing(..), availNames, icPrintUnqual, +import HscTypes ( InteractiveContext(..), ExternalPackageState( eps_PTE ), + HomeModInfo(..), typeEnvElts, typeEnvClasses, + TyThing(..), availName, availNames, icPrintUnqual, ModIface(..), ModDetails(..) ) import BasicTypes ( RecFlag(..), Fixity ) import Bag ( unitBag ) +import ListSetOps ( removeDups ) import Panic ( ghcError, GhcException(..) ) #endif import FastString ( mkFastString ) -import Util ( sortLt ) +import Util ( sortLe ) import Bag ( unionBags, snocBag ) import Maybe ( isJust ) @@ -128,7 +138,7 @@ import Maybe ( isJust ) \begin{code} tcRnModule :: HscEnv -> Located (HsModule RdrName) - -> IO (Maybe TcGblEnv) + -> IO (Messages, Maybe TcGblEnv) tcRnModule hsc_env (L loc (HsModule maybe_mod exports import_decls local_decls mod_deprec)) @@ -144,6 +154,12 @@ tcRnModule hsc_env (L loc (HsModule maybe_mod exports addSrcSpan loc $ do { -- Deal with imports; sets tcg_rdr_env, tcg_imports (rdr_env, imports) <- rnImports import_decls ; + + -- In one-shot mode, record boot-file info in the EPS + ifM (isOneShot (hsc_mode hsc_env)) $ + updateEps_ (\eps -> eps { eps_is_boot = imp_dep_mods imports }) ; + + -- Update the gbl env updGblEnv ( \ gbl -> gbl { tcg_rdr_env = rdr_env, tcg_imports = tcg_imports gbl `plusImportAvails` imports }) $ do { @@ -211,287 +227,6 @@ tcRnModule hsc_env (L loc (HsModule maybe_mod exports %************************************************************************ %* * - The interactive interface -%* * -%************************************************************************ - -\begin{code} -#ifdef GHCI -tcRnStmt :: HscEnv - -> InteractiveContext - -> LStmt RdrName - -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id)) - -- The returned [Name] is the same as the input except for - -- ExprStmt, in which case the returned [Name] is [itName] - -- - -- The returned TypecheckedHsExpr is of type IO [ () ], - -- a list of the bound values, coerced to (). - -tcRnStmt hsc_env ictxt rdr_stmt - = initTc hsc_env iNTERACTIVE $ - setInteractiveContext ictxt $ do { - - -- Rename; use CmdLineMode because tcRnStmt is only used interactively - ([rn_stmt], fvs) <- rnStmts DoExpr [rdr_stmt] ; - traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ; - failIfErrsM ; - - -- The real work is done here - (bound_ids, tc_expr) <- tcUserStmt rn_stmt ; - - traceTc (text "tcs 1") ; - let { -- Make all the bound ids "global" ids, now that - -- they're notionally top-level bindings. This is - -- important: otherwise when we come to compile an expression - -- using these ids later, the byte code generator will consider - -- the occurrences to be free rather than global. - global_ids = map (globaliseId VanillaGlobal) bound_ids ; - - -- Update the interactive context - rn_env = ic_rn_local_env ictxt ; - type_env = ic_type_env ictxt ; - - bound_names = map idName global_ids ; - new_rn_env = extendLocalRdrEnv rn_env bound_names ; - - -- Remove any shadowed bindings from the type_env; - -- they are inaccessible but might, I suppose, cause - -- a space leak if we leave them there - shadowed = [ n | name <- bound_names, - let rdr_name = mkRdrUnqual (nameOccName name), - Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ; - - filtered_type_env = delListFromNameEnv type_env shadowed ; - new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ; - - new_ic = ictxt { ic_rn_local_env = new_rn_env, - ic_type_env = new_type_env } - } ; - - dumpOptTcRn Opt_D_dump_tc - (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids, - text "Typechecked expr" <+> ppr tc_expr]) ; - - returnM (new_ic, bound_names, tc_expr) - } -\end{code} - - -Here is the grand plan, implemented in tcUserStmt - - What you type The IO [HValue] that hscStmt returns - ------------- ------------------------------------ - let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...] - bindings: [x,y,...] - - pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...] - bindings: [x,y,...] - - expr (of IO type) ==> expr >>= \ v -> return [coerce HVal v] - [NB: result not printed] bindings: [it] - - expr (of non-IO type, ==> let v = expr in print v >> return [coerce HVal v] - result showable) bindings: [it] - - expr (of non-IO type, - result not showable) ==> error - - -\begin{code} ---------------------------- -tcUserStmt :: LStmt Name -> TcM ([Id], LHsExpr Id) -tcUserStmt (L _ (ExprStmt expr _)) - = newUnique `thenM` \ uniq -> - let - fresh_it = itName uniq - the_bind = noLoc $ FunBind (noLoc fresh_it) False - [ mkSimpleMatch [] expr placeHolderType ] - in - tryTcLIE_ (do { -- Try this if the other fails - traceTc (text "tcs 1b") ; - tc_stmts [ - nlLetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive], - nlExprStmt (nlHsApp (nlHsVar printName) - (nlHsVar fresh_it)) - ] }) - (do { -- Try this first - traceTc (text "tcs 1a") ; - tc_stmts [nlBindStmt (nlVarPat fresh_it) expr] }) - -tcUserStmt stmt = tc_stmts [stmt] - ---------------------------- -tc_stmts stmts - = do { ioTyCon <- tcLookupTyCon ioTyConName ; - let { - ret_ty = mkListTy unitTy ; - io_ret_ty = mkTyConApp ioTyCon [ret_ty] ; - - names = map unLoc (collectStmtsBinders stmts) ; - - stmt_ctxt = SC { sc_what = DoExpr, - sc_rhs = check_rhs, - sc_body = check_body, - sc_ty = ret_ty } ; - - check_rhs rhs rhs_ty = tcCheckRho rhs (mkTyConApp ioTyCon [rhs_ty]) ; - check_body body = tcCheckRho body io_ret_ty ; - - -- mk_return builds the expression - -- returnIO @ [()] [coerce () x, .., coerce () z] - -- - -- Despite the inconvenience of building the type applications etc, - -- this *has* to be done in type-annotated post-typecheck form - -- because we are going to return a list of *polymorphic* values - -- coerced to type (). If we built a *source* stmt - -- return [coerce x, ..., coerce z] - -- 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_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy]) - (nlHsVar id) ; - - io_ty = mkTyConApp ioTyCon [] - } ; - - -- OK, we're ready to typecheck the stmts - traceTc (text "tcs 2") ; - ((ids, tc_expr), lie) <- getLIE $ do { - (ids, tc_stmts) <- tcStmtsAndThen combine stmt_ctxt stmts $ - do { - -- Look up the names right in the middle, - -- where they will all be in scope - ids <- mappM tcLookupId names ; - ret_id <- tcLookupId returnIOName ; -- return @ IO - return (ids, [nlResultStmt (mk_return ret_id ids)]) } ; - - io_ids <- mappM (tcStdSyntaxName DoOrigin io_ty) monadNames ; - return (ids, noLoc (HsDo DoExpr tc_stmts io_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 ; - - return (zonked_ids, zonked_expr) - } - where - combine stmt (ids, stmts) = (ids, stmt:stmts) -\end{code} - - -tcRnExpr just finds the type of an expression - -\begin{code} -tcRnExpr :: HscEnv - -> InteractiveContext - -> LHsExpr RdrName - -> IO (Maybe Type) -tcRnExpr hsc_env ictxt rdr_expr - = initTc hsc_env iNTERACTIVE $ - setInteractiveContext ictxt $ do { - - (rn_expr, fvs) <- rnLExpr rdr_expr ; - failIfErrsM ; - - -- Now typecheck the expression; - -- it might have a rank-2 type (e.g. :t runST) - ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ; - ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ; - tcSimplifyInteractive lie_top ; - - let { all_expr_ty = mkForAllTys qtvs $ - mkFunTys (map idType dict_ids) $ - res_ty } ; - zonkTcType all_expr_ty - } - where - smpl_doc = ptext SLIT("main expression") -\end{code} - - -\begin{code} -tcRnThing :: HscEnv - -> InteractiveContext - -> RdrName - -> IO (Maybe [(IfaceDecl, Fixity)]) --- Look up a RdrName and return all the TyThings it might be --- A capitalised RdrName is given to us in the DataName namespace, --- but we want to treat it as *both* a data constructor --- *and* as a type or class constructor; --- hence the call to dataTcOccs, and we return up to two results -tcRnThing hsc_env ictxt rdr_name - = initTc hsc_env iNTERACTIVE $ - setInteractiveContext ictxt $ do { - - -- If the identifier is a constructor (begins with an - -- upper-case letter), then we need to consider both - -- constructor and type class identifiers. - let { rdr_names = dataTcOccs rdr_name } ; - - -- results :: [(Messages, Maybe Name)] - results <- mapM (tryTc . lookupOccRn) rdr_names ; - - -- The successful lookups will be (Just name) - let { (warns_s, good_names) = unzip [ (msgs, name) - | (msgs, Just name) <- results] ; - errs_s = [msgs | (msgs, Nothing) <- results] } ; - - -- Fail if nothing good happened, else add warnings - if null good_names then - -- No lookup succeeded, so - -- pick the first error message and report it - -- ToDo: If one of the errors is "could be Foo.X or Baz.X", - -- while the other is "X is not in scope", - -- we definitely want the former; but we might pick the latter - do { addMessages (head errs_s) ; failM } - else -- Add deprecation warnings - mapM_ addMessages warns_s ; - - -- And lookup up the entities - mapM do_one good_names - } - where - do_one name = do { thing <- tcLookupGlobal name - ; fixity <- lookupFixityRn name - ; return (toIfaceDecl ictxt thing, fixity) } - -toIfaceDecl :: InteractiveContext -> TyThing -> IfaceDecl -toIfaceDecl ictxt thing - = tyThingToIfaceDecl True {- Discard IdInfo -} emptyNameSet {- Show data cons -} - ext_nm thing - where - unqual = icPrintUnqual ictxt - ext_nm n | unqual n = LocalTop (nameOccName n) -- What a hack - | otherwise = ExtPkg (nameModuleName n) (nameOccName n) -\end{code} - - -\begin{code} -setInteractiveContext :: InteractiveContext -> TcRn a -> TcRn a -setInteractiveContext icxt thing_inside - = traceTc (text "setIC" <+> ppr (ic_type_env icxt)) `thenM_` - (updGblEnv (\env -> env {tcg_rdr_env = ic_rn_gbl_env icxt, - tcg_type_env = ic_type_env icxt}) $ - updLclEnv (\env -> env {tcl_rdr = ic_rn_local_env icxt}) $ - thing_inside) -#endif /* GHCI */ -\end{code} - -%************************************************************************ -%* * Type-checking external-core modules %* * %************************************************************************ @@ -499,7 +234,7 @@ setInteractiveContext icxt thing_inside \begin{code} tcRnExtCore :: HscEnv -> HsExtCore RdrName - -> IO (Maybe ModGuts) + -> IO (Messages, Maybe ModGuts) -- Nothing => some error occurred tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds) @@ -789,22 +524,347 @@ tcTopSrcDecls \end{code} +%************************************************************************ +%* * + Checking for 'main' +%* * +%************************************************************************ + +\begin{code} +checkMain + = do { ghci_mode <- getGhciMode ; + tcg_env <- getGblEnv ; + + mb_main_mod <- readMutVar v_MainModIs ; + mb_main_fn <- readMutVar v_MainFunIs ; + let { main_mod = case mb_main_mod of { + Just mod -> mkModuleName mod ; + Nothing -> mAIN_Name } ; + main_fn = case mb_main_fn of { + Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ; + Nothing -> main_RDR_Unqual } } ; + + check_main ghci_mode tcg_env main_mod main_fn + } + + +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! + -- + -- ToDo: We have to return the main_name separately, because it's a + -- bona fide 'use', and should be recorded as such, but the others + -- aren't + -- + -- Blimey: a whole page of code to do this... + | mod_name /= main_mod + = return tcg_env + + | otherwise + = addErrCtxt mainCtxt $ + do { mb_main <- lookupSrcOcc_maybe main_fn + -- Check that 'main' is in scope + -- It might be imported from another module! + ; case mb_main of { + Nothing -> do { complain_no_main + ; return tcg_env } ; + Just main_name -> do + { let { rhs = nlHsApp (nlHsVar runIOName) (nlHsVar main_name) } + -- :Main.main :: IO () = runIO main + + ; (main_expr, ty) <- addSrcSpan (srcLocSpan (getSrcLoc main_name)) $ + tcInferRho rhs + + ; let { root_main_id = mkExportedLocalId rootMainName ty ; + main_bind = noLoc (VarBind root_main_id main_expr) } + + ; return (tcg_env { tcg_binds = tcg_binds tcg_env + `snocBag` main_bind, + tcg_dus = tcg_dus tcg_env + `plusDU` usesOnly (unitFV main_name) + }) + }}} + where + mod_name = moduleName (tcg_mod tcg_env) + + complain_no_main | ghci_mode == Interactive = return () + | otherwise = failWithTc noMainMsg + -- In interactive mode, don't worry about the absence of 'main' + -- In other modes, fail altogether, so that we don't go on + -- and complain a second time when processing the export list. + + mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn) + noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn) + <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod) +\end{code} + + %********************************************************* %* * - mkGlobalContext: make up an interactive context - - Used for initialising the lexical environment - of the interactive read-eval-print loop + GHCi stuff %* * %********************************************************* \begin{code} #ifdef GHCI +setInteractiveContext :: InteractiveContext -> TcRn a -> TcRn a +setInteractiveContext icxt thing_inside + = traceTc (text "setIC" <+> ppr (ic_type_env icxt)) `thenM_` + (updGblEnv (\env -> env {tcg_rdr_env = ic_rn_gbl_env icxt, + tcg_type_env = ic_type_env icxt}) $ + updLclEnv (\env -> env {tcl_rdr = ic_rn_local_env icxt}) $ + thing_inside) +\end{code} + + +\begin{code} +tcRnStmt :: HscEnv + -> InteractiveContext + -> LStmt RdrName + -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id)) + -- The returned [Name] is the same as the input except for + -- ExprStmt, in which case the returned [Name] is [itName] + -- + -- The returned TypecheckedHsExpr is of type IO [ () ], + -- a list of the bound values, coerced to (). + +tcRnStmt hsc_env ictxt rdr_stmt + = initTcPrintErrors hsc_env iNTERACTIVE $ + setInteractiveContext ictxt $ do { + + -- Rename; use CmdLineMode because tcRnStmt is only used interactively + ([rn_stmt], fvs) <- rnStmts DoExpr [rdr_stmt] ; + traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ; + failIfErrsM ; + + -- The real work is done here + (bound_ids, tc_expr) <- tcUserStmt rn_stmt ; + + traceTc (text "tcs 1") ; + let { -- Make all the bound ids "global" ids, now that + -- they're notionally top-level bindings. This is + -- important: otherwise when we come to compile an expression + -- using these ids later, the byte code generator will consider + -- the occurrences to be free rather than global. + global_ids = map (globaliseId VanillaGlobal) bound_ids ; + + -- Update the interactive context + rn_env = ic_rn_local_env ictxt ; + type_env = ic_type_env ictxt ; + + bound_names = map idName global_ids ; + new_rn_env = extendLocalRdrEnv rn_env bound_names ; + + -- Remove any shadowed bindings from the type_env; + -- they are inaccessible but might, I suppose, cause + -- a space leak if we leave them there + shadowed = [ n | name <- bound_names, + let rdr_name = mkRdrUnqual (nameOccName name), + Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ; + + filtered_type_env = delListFromNameEnv type_env shadowed ; + new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ; + + new_ic = ictxt { ic_rn_local_env = new_rn_env, + ic_type_env = new_type_env } + } ; + + dumpOptTcRn Opt_D_dump_tc + (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids, + text "Typechecked expr" <+> ppr tc_expr]) ; + + returnM (new_ic, bound_names, tc_expr) + } +\end{code} + + +Here is the grand plan, implemented in tcUserStmt + + What you type The IO [HValue] that hscStmt returns + ------------- ------------------------------------ + let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...] + bindings: [x,y,...] + + pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...] + bindings: [x,y,...] + + expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it] + [NB: result not printed] bindings: [it] + + expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it] + result showable) bindings: [it] + + expr (of non-IO type, + result not showable) ==> error + + +\begin{code} +--------------------------- +tcUserStmt :: LStmt Name -> TcM ([Id], LHsExpr Id) +tcUserStmt (L _ (ExprStmt expr _)) + = newUnique `thenM` \ uniq -> + let + fresh_it = itName uniq + the_bind = noLoc $ FunBind (noLoc fresh_it) False + [ mkSimpleMatch [] expr placeHolderType ] + in + tryTcLIE_ (do { -- Try this if the other fails + traceTc (text "tcs 1b") ; + tc_stmts [ + nlLetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive], + nlExprStmt (nlHsApp (nlHsVar printName) + (nlHsVar fresh_it)) + ] }) + (do { -- Try this first + traceTc (text "tcs 1a") ; + tc_stmts [nlBindStmt (nlVarPat fresh_it) expr] }) + +tcUserStmt stmt = tc_stmts [stmt] + +--------------------------- +tc_stmts stmts + = do { ioTyCon <- tcLookupTyCon ioTyConName ; + let { + ret_ty = mkListTy unitTy ; + io_ret_ty = mkTyConApp ioTyCon [ret_ty] ; + + names = map unLoc (collectStmtsBinders stmts) ; + + stmt_ctxt = SC { sc_what = DoExpr, + sc_rhs = check_rhs, + sc_body = check_body, + sc_ty = ret_ty } ; + + check_rhs rhs rhs_ty = tcCheckRho rhs (mkTyConApp ioTyCon [rhs_ty]) ; + check_body body = tcCheckRho body io_ret_ty ; + + -- mk_return builds the expression + -- returnIO @ [()] [coerce () x, .., coerce () z] + -- + -- Despite the inconvenience of building the type applications etc, + -- this *has* to be done in type-annotated post-typecheck form + -- because we are going to return a list of *polymorphic* values + -- coerced to type (). If we built a *source* stmt + -- return [coerce x, ..., coerce z] + -- 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_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy]) + (nlHsVar id) ; + + io_ty = mkTyConApp ioTyCon [] + } ; + + -- OK, we're ready to typecheck the stmts + traceTc (text "tcs 2") ; + ((ids, tc_expr), lie) <- getLIE $ do { + (ids, tc_stmts) <- tcStmtsAndThen combine stmt_ctxt stmts $ + do { + -- Look up the names right in the middle, + -- where they will all be in scope + ids <- mappM tcLookupId names ; + ret_id <- tcLookupId returnIOName ; -- return @ IO + return (ids, [nlResultStmt (mk_return ret_id ids)]) } ; + + io_ids <- mappM (tcStdSyntaxName DoOrigin io_ty) monadNames ; + return (ids, noLoc (HsDo DoExpr tc_stmts io_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 + combine stmt (ids, stmts) = (ids, stmt:stmts) + bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"), + nest 2 (ppr id <+> dcolon <+> ppr (idType id))]) +\end{code} + + +tcRnExpr just finds the type of an expression + +\begin{code} +tcRnExpr :: HscEnv + -> InteractiveContext + -> LHsExpr RdrName + -> IO (Maybe Type) +tcRnExpr hsc_env ictxt rdr_expr + = initTcPrintErrors hsc_env iNTERACTIVE $ + setInteractiveContext ictxt $ do { + + (rn_expr, fvs) <- rnLExpr rdr_expr ; + failIfErrsM ; + + -- Now typecheck the expression; + -- it might have a rank-2 type (e.g. :t runST) + ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ; + ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ; + tcSimplifyInteractive lie_top ; + + let { all_expr_ty = mkForAllTys qtvs $ + mkFunTys (map idType dict_ids) $ + res_ty } ; + zonkTcType all_expr_ty + } + where + smpl_doc = ptext SLIT("main expression") +\end{code} + +tcRnType just finds the kind of a type + +\begin{code} +tcRnType :: HscEnv + -> InteractiveContext + -> LHsType RdrName + -> IO (Maybe Kind) +tcRnType hsc_env ictxt rdr_type + = initTcPrintErrors hsc_env iNTERACTIVE $ + setInteractiveContext ictxt $ do { + + rn_type <- rnLHsType doc rdr_type ; + failIfErrsM ; + + -- Now kind-check the type + (ty', kind) <- kcHsType rn_type ; + return kind + } + where + doc = ptext SLIT("In GHCi input") + +#endif /* GHCi */ +\end{code} + + +%************************************************************************ +%* * + More GHCi stuff, to do with browsing and getting info +%* * +%************************************************************************ + +\begin{code} +#ifdef GHCI mkExportEnv :: HscEnv -> [ModuleName] -- Expose these modules' exports only -> IO GlobalRdrEnv - mkExportEnv hsc_env exports - = do { mb_envs <- initTc hsc_env iNTERACTIVE $ + = do { mb_envs <- initTcPrintErrors hsc_env iNTERACTIVE $ mappM getModuleExports exports ; case mb_envs of Just envs -> return (foldr plusGlobalRdrEnv emptyGlobalRdrEnv envs) @@ -815,6 +875,9 @@ mkExportEnv hsc_env exports getModuleExports :: ModuleName -> TcM GlobalRdrEnv getModuleExports mod = do { iface <- load_iface mod + ; loadOrphanModules (dep_orphs (mi_deps iface)) + -- Load any orphan-module interfaces, + -- so their instances are visible ; avails <- exportsToAvails (mi_exports iface) ; let { gres = [ GRE { gre_name = name, gre_prov = vanillaProv mod } | avail <- avails, name <- availNames avail ] } @@ -836,14 +899,14 @@ getModuleContents -> IO (Maybe [IfaceDecl]) getModuleContents hsc_env ictxt mod exports_only - = initTc hsc_env iNTERACTIVE (get_mod_contents exports_only) + = initTcPrintErrors hsc_env iNTERACTIVE (get_mod_contents exports_only) where get_mod_contents exports_only - | not exports_only -- We want the whole top-level type env + | not exports_only -- We want the whole top-level type env -- so it had better be a home module = do { hpt <- getHpt ; case lookupModuleEnvByName hpt mod of - Just mod_info -> return (map (toIfaceDecl ictxt) $ + Just mod_info -> return (map toIfaceDecl $ filter wantToSee $ typeEnvElts $ md_types (hm_details mod_info)) @@ -859,18 +922,21 @@ getModuleContents hsc_env ictxt mod exports_only get_decl avail = do { thing <- tcLookupGlobal (availName avail) - ; return (filter_decl (availOccs avail) (toIfaceDecl ictxt thing)) } + ; return (filter_decl (availOccs avail) (toIfaceDecl thing)) } --------------------- filter_decl occs decl@(IfaceClass {ifSigs = sigs}) = decl { ifSigs = filter (keep_sig occs) sigs } -filter_decl occs decl@(IfaceData {ifCons = DataCons cons}) - = decl { ifCons = DataCons (filter (keep_con occs) cons) } +filter_decl occs decl@(IfaceData {ifCons = IfDataTyCon cons}) + = decl { ifCons = IfDataTyCon (filter (keep_con occs) cons) } +filter_decl occs decl@(IfaceData {ifCons = IfNewTyCon con}) + | keep_con occs con = decl + | otherwise = decl {ifCons = IfAbstractTyCon} -- Hmm? filter_decl occs decl = decl -keep_sig occs (IfaceClassOp occ _ _) = occ `elem` occs -keep_con occs (IfaceConDecl occ _ _ _ _ _) = occ `elem` occs +keep_sig occs (IfaceClassOp occ _ _) = occ `elem` occs +keep_con occs (IfaceConDecl occ _ _ _ _ _ _) = occ `elem` occs availOccs avail = map nameOccName (availNames avail) @@ -886,83 +952,109 @@ load_iface mod = loadSrcInterface doc mod False {- Not boot iface -} --------------------- noRdrEnvErr mod = ptext SLIT("No top-level environment available for module") <+> quotes (ppr mod) -#endif \end{code} -%************************************************************************ -%* * - Checking for 'main' -%* * -%************************************************************************ - \begin{code} -checkMain - = do { ghci_mode <- getGhciMode ; - tcg_env <- getGblEnv ; +tcRnGetInfo :: HscEnv + -> InteractiveContext + -> RdrName + -> IO (Maybe [(IfaceDecl, + Fixity, SrcLoc, + [(IfaceInst, SrcLoc)])]) +-- Used to implemnent :info in GHCi +-- +-- Look up a RdrName and return all the TyThings it might be +-- A capitalised RdrName is given to us in the DataName namespace, +-- but we want to treat it as *both* a data constructor +-- *and* as a type or class constructor; +-- hence the call to dataTcOccs, and we return up to two results +tcRnGetInfo hsc_env ictxt rdr_name + = initTcPrintErrors hsc_env iNTERACTIVE $ + setInteractiveContext ictxt $ do { - mb_main_mod <- readMutVar v_MainModIs ; - mb_main_fn <- readMutVar v_MainFunIs ; - let { main_mod = case mb_main_mod of { - Just mod -> mkModuleName mod ; - Nothing -> mAIN_Name } ; - main_fn = case mb_main_fn of { - Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ; - Nothing -> main_RDR_Unqual } } ; - - check_main ghci_mode tcg_env main_mod main_fn - } + -- If the identifier is a constructor (begins with an + -- upper-case letter), then we need to consider both + -- constructor and type class identifiers. + let { rdr_names = dataTcOccs rdr_name } ; + -- results :: [(Messages, Maybe Name)] + results <- mapM (tryTc . lookupOccRn) rdr_names ; -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! - -- - -- ToDo: We have to return the main_name separately, because it's a - -- bona fide 'use', and should be recorded as such, but the others - -- aren't - -- - -- Blimey: a whole page of code to do this... - | mod_name /= main_mod - = return tcg_env + traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]); + -- The successful lookups will be (Just name) + let { (warns_s, good_names) = unzip [ (msgs, name) + | (msgs, Just name) <- results] ; + errs_s = [msgs | (msgs, Nothing) <- results] } ; - | otherwise - = addErrCtxt mainCtxt $ - do { mb_main <- lookupSrcOcc_maybe main_fn - -- Check that 'main' is in scope - -- It might be imported from another module! - ; case mb_main of { - Nothing -> do { complain_no_main - ; return tcg_env } ; - Just main_name -> do - { let { rhs = nlHsApp (nlHsVar runIOName) (nlHsVar main_name) } - -- :Main.main :: IO () = runIO main + -- Fail if nothing good happened, else add warnings + if null good_names then + -- No lookup succeeded, so + -- pick the first error message and report it + -- ToDo: If one of the errors is "could be Foo.X or Baz.X", + -- while the other is "X is not in scope", + -- we definitely want the former; but we might pick the latter + do { addMessages (head errs_s) ; failM } + else -- Add deprecation warnings + mapM_ addMessages warns_s ; + + -- And lookup up the entities, avoiding duplicates, which arise + -- because constructors and record selectors are represented by + -- their parent declaration + let { do_one name = do { thing <- tcLookupGlobal name + ; let decl = toIfaceDecl thing + ; fixity <- lookupFixityRn name + ; insts <- lookupInsts thing + ; return (decl, fixity, getSrcLoc thing, + map mk_inst insts) } ; + -- For the SrcLoc, the 'thing' has better info than + -- the 'name' because getting the former forced the + -- declaration to be loaded into the cache + mk_inst dfun = (dfunToIfaceInst dfun, getSrcLoc dfun) ; + cmp (d1,_,_,_) (d2,_,_,_) = ifName d1 `compare` ifName d2 } ; + results <- mapM do_one good_names ; + return (fst (removeDups cmp results)) + } - ; (main_expr, ty) <- addSrcSpan (srcLocSpan (getSrcLoc main_name)) $ - tcInferRho rhs +lookupInsts :: TyThing -> TcM [DFunId] +lookupInsts (AClass cls) + = do { loadImportedInsts cls [] -- [] means load all instances for cls + ; inst_envs <- tcGetInstEnvs + ; return [df | (_,_,df) <- classInstances inst_envs cls] } + +lookupInsts (ATyCon tc) + = do { eps <- getEps -- Load all instances for all classes that are + -- in the type environment (which are all the ones + -- we've seen in any interface file so far + ; mapM_ (\c -> loadImportedInsts c []) + (typeEnvClasses (eps_PTE eps)) + ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all + ; return (get home_ie ++ get pkg_ie) } + where + get ie = [df | (_,_,df) <- instEnvElts ie, relevant df] + relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df) + tc_name = tyConName tc - ; let { root_main_id = mkExportedLocalId rootMainName ty ; - main_bind = noLoc (VarBind root_main_id main_expr) } +lookupInsts other = return [] - ; return (tcg_env { tcg_binds = tcg_binds tcg_env - `snocBag` main_bind, - tcg_dus = tcg_dus tcg_env - `plusDU` usesOnly (unitFV main_name) - }) - }}} + +toIfaceDecl :: TyThing -> IfaceDecl +toIfaceDecl thing + = tyThingToIfaceDecl True -- Discard IdInfo + emptyNameSet -- Show data cons + ext_nm (munge thing) where - mod_name = moduleName (tcg_mod tcg_env) - - complain_no_main | ghci_mode == Interactive = return () - | otherwise = failWithTc noMainMsg - -- In interactive mode, don't worry about the absence of 'main' - -- In other modes, fail altogether, so that we don't go on - -- and complain a second time when processing the export list. + ext_nm n = ExtPkg (nameModuleName n) (nameOccName n) - mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn) - noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn) - <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod) -\end{code} + -- munge transforms a thing to it's "parent" thing + munge (ADataCon dc) = ATyCon (dataConTyCon dc) + munge (AnId id) = case globalIdDetails id of + RecordSelId lbl -> ATyCon (fieldLabelTyCon lbl) + ClassOpId cls -> AClass cls + other -> AnId id + munge other_thing = other_thing +#endif /* GHCI */ +\end{code} %************************************************************************ %* * @@ -988,7 +1080,7 @@ tcDump env } where short_dump = pprTcGblEnv env - full_dump = ppr (tcg_binds env) + full_dump = pprLHsBinds (tcg_binds env) -- NB: foreign x-d's have undefined's in their types; -- hence can't show the tc_fords @@ -1043,9 +1135,9 @@ ppr_insts dfun_ids = text "INSTANCES" $$ nest 4 (ppr_sigs dfun_ids) ppr_sigs :: [Var] -> SDoc ppr_sigs ids -- Print type signatures; sort by OccName - = vcat (map ppr_sig (sortLt lt_sig ids)) + = vcat (map ppr_sig (sortLe le_sig ids)) where - lt_sig id1 id2 = getOccName id1 < getOccName id2 + le_sig id1 id2 = getOccName id1 <= getOccName id2 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id)) ppr_rules :: [IdCoreRule] -> SDoc