2 % (c) The GRASP/AQUA Project, Glasgow University, 1993-2000
5 \section[GHC_Main]{Main driver for Glasgow Haskell compiler}
8 module HscMain ( HscResult(..), hscMain,
10 hscStmt, hscThing, hscModuleContents,
12 initPersistentCompilerState ) where
14 #include "HsVersions.h"
18 import ByteCodeGen ( byteCodeGen )
19 import CoreTidy ( tidyCoreExpr )
20 import CorePrep ( corePrepExpr )
21 import Rename ( renameStmt, renameRdrName, slurpIface )
22 import RdrName ( rdrNameOcc, setRdrNameOcc )
23 import RdrHsSyn ( RdrNameStmt )
24 import OccName ( dataName, tcClsName,
25 occNameSpace, setOccNameSpace )
27 import Id ( Id, idName, setGlobalIdDetails )
28 import IdInfo ( GlobalIdDetails(VanillaGlobal) )
29 import Name ( isLocalName )
30 import NameEnv ( lookupNameEnv )
31 import RdrName ( rdrEnvElts )
32 import PrelNames ( iNTERACTIVE )
33 import StringBuffer ( stringToStringBuffer )
34 import FastString ( mkFastString )
35 import Maybes ( catMaybes )
42 import RdrName ( mkRdrOrig )
44 import IdInfo ( CafInfo(..), CgInfoEnv, CgInfo(..) )
45 import StringBuffer ( hGetStringBuffer, freeStringBuffer )
47 import Lex ( PState(..), ParseResult(..) )
48 import SrcLoc ( mkSrcLoc )
49 import Finder ( findModule )
50 import Rename ( checkOldIface, renameModule, closeIfaceDecls )
51 import Rules ( emptyRuleBase )
52 import PrelInfo ( wiredInThingEnv, wiredInThings )
53 import PrelRules ( builtinRules )
54 import PrelNames ( knownKeyNames )
55 import MkIface ( mkFinalIface )
57 import InstEnv ( emptyInstEnv )
60 import CoreUtils ( coreBindsSize )
61 import CoreTidy ( tidyCorePgm )
62 import CorePrep ( corePrepPgm )
64 import CoreToStg ( coreToStg )
65 import SimplStg ( stg2stg )
66 import CodeGen ( codeGen )
67 import CodeOutput ( codeOutput )
69 import Module ( ModuleName, moduleName, mkHomeModule,
70 moduleUserString, lookupModuleEnv )
72 import DriverState ( v_HCHeader )
73 import ErrUtils ( dumpIfSet_dyn, showPass, printError )
74 import Util ( unJust )
75 import UniqSupply ( mkSplitUniqSupply )
77 import Bag ( consBag, emptyBag )
79 import HscStats ( ppSourceStats )
81 import FiniteMap ( FiniteMap, plusFM, emptyFM, addToFM )
82 import OccName ( OccName )
83 import Name ( Name, nameModule, nameOccName, getName, isGlobalName )
84 import NameEnv ( emptyNameEnv, mkNameEnv )
85 import Module ( Module )
87 import IOExts ( newIORef, readIORef, writeIORef,
91 import Maybe ( isJust, fromJust )
94 import MkExternalCore ( emitExternalCore )
98 %************************************************************************
100 \subsection{The main compiler pipeline}
102 %************************************************************************
106 -- compilation failed
107 = HscFail PersistentCompilerState -- updated PCS
108 -- concluded that it wasn't necessary
109 | HscNoRecomp PersistentCompilerState -- updated PCS
110 ModDetails -- new details (HomeSymbolTable additions)
111 ModIface -- new iface (if any compilation was done)
113 | HscRecomp PersistentCompilerState -- updated PCS
114 ModDetails -- new details (HomeSymbolTable additions)
115 ModIface -- new iface (if any compilation was done)
116 Bool -- stub_h exists
117 Bool -- stub_c exists
119 (Maybe ([UnlinkedBCO],ItblEnv)) -- interpreted code, if any
121 (Maybe ()) -- no interpreted code whatsoever
124 -- no errors or warnings; the individual passes
125 -- (parse/rename/typecheck) print messages themselves
131 -> ModuleLocation -- location info
132 -> Bool -- True <=> source unchanged
133 -> Bool -- True <=> have an object file (for msgs only)
134 -> Maybe ModIface -- old interface, if available
135 -> HomeSymbolTable -- for home module ModDetails
137 -> PersistentCompilerState -- IN: persistent compiler state
140 hscMain ghci_mode dflags mod location source_unchanged have_object
141 maybe_old_iface hst hit pcs
142 = {-# SCC "hscMain" #-}
144 showPass dflags ("Checking old interface for hs = "
145 ++ show (ml_hs_file location)
146 ++ ", hspp = " ++ show (ml_hspp_file location));
148 (pcs_ch, errs_found, (recomp_reqd, maybe_checked_iface))
149 <- _scc_ "checkOldIface"
150 checkOldIface ghci_mode dflags hit hst pcs mod (ml_hi_file location)
151 source_unchanged maybe_old_iface;
154 return (HscFail pcs_ch)
157 let no_old_iface = not (isJust maybe_checked_iface)
158 what_next | recomp_reqd || no_old_iface = hscRecomp
159 | otherwise = hscNoRecomp
161 what_next ghci_mode dflags have_object mod location
162 maybe_checked_iface hst hit pcs_ch
166 -- we definitely expect to have the old interface available
167 hscNoRecomp ghci_mode dflags have_object
168 mod location (Just old_iface) hst hit pcs_ch
169 | ghci_mode == OneShot
171 when (verbosity dflags > 0) $
172 hPutStrLn stderr "compilation IS NOT required";
173 let { bomb = panic "hscNoRecomp:OneShot" };
174 return (HscNoRecomp pcs_ch bomb bomb)
178 when (verbosity dflags >= 1) $
179 hPutStrLn stderr ("Skipping " ++
180 showModMsg have_object mod location);
183 (pcs_cl, closure_errs, cl_hs_decls)
184 <- closeIfaceDecls dflags hit hst pcs_ch old_iface ;
186 return (HscFail pcs_cl)
191 <- typecheckIface dflags pcs_cl hst old_iface cl_hs_decls;
193 case maybe_tc_result of {
194 Nothing -> return (HscFail pcs_cl);
195 Just (pcs_tc, new_details) ->
197 return (HscNoRecomp pcs_tc new_details old_iface)
200 hscRecomp ghci_mode dflags have_object
201 mod location maybe_checked_iface hst hit pcs_ch
203 -- what target are we shooting for?
204 ; let toInterp = dopt_HscLang dflags == HscInterpreted
205 ; let toNothing = dopt_HscLang dflags == HscNothing
207 ; when (ghci_mode /= OneShot && verbosity dflags >= 1) $
208 hPutStrLn stderr ("Compiling " ++
209 showModMsg (not toInterp) mod location);
214 ; maybe_parsed <- myParseModule dflags
215 (unJust "hscRecomp:hspp" (ml_hspp_file location))
216 ; case maybe_parsed of {
217 Nothing -> return (HscFail pcs_ch);
218 Just rdr_module -> do {
219 ; let this_mod = mkHomeModule (hsModuleName rdr_module)
224 ; (pcs_rn, print_unqualified, maybe_rn_result)
226 renameModule dflags hit hst pcs_ch this_mod rdr_module
227 ; case maybe_rn_result of {
228 Nothing -> return (HscFail pcs_ch{-was: pcs_rn-});
229 Just (is_exported, new_iface, rn_hs_decls) -> do {
231 -- In interactive mode, we don't want to discard any top-level
232 -- entities at all (eg. do not inline them away during
233 -- simplification), and retain them all in the TypeEnv so they are
234 -- available from the command line.
236 -- isGlobalName separates the user-defined top-level names from those
237 -- introduced by the type checker.
239 ; let dont_discard | ghci_mode == Interactive = isGlobalName
240 | otherwise = is_exported
247 typecheckModule dflags pcs_rn hst new_iface
248 print_unqualified rn_hs_decls
249 ; case maybe_tc_result of {
250 Nothing -> return (HscFail pcs_ch{-was: pcs_rn-});
251 Just (pcs_tc, tc_result) -> do {
256 ; (ds_details, foreign_stuff)
258 deSugar dflags pcs_tc hst this_mod print_unqualified tc_result
261 <- _scc_ "pcs_middle"
262 if ghci_mode == OneShot
263 then do init_pcs <- initPersistentCompilerState
264 init_prs <- initPersistentRenamerState
266 rules = pcs_rules pcs_tc
267 orig_tc = prsOrig (pcs_PRS pcs_tc)
268 new_prs = init_prs{ prsOrig=orig_tc }
270 orig_tc `seq` rules `seq` new_prs `seq`
271 return init_pcs{ pcs_PRS = new_prs,
275 -- alive at this point:
286 core2core dflags pcs_middle hst dont_discard ds_details
291 ; cg_info_ref <- newIORef Nothing ;
292 ; let cg_info :: CgInfoEnv
293 cg_info = unsafePerformIO $ do {
294 maybe_cg_env <- readIORef cg_info_ref ;
296 Just env -> return env
297 Nothing -> do { printError "Urk! Looked at CgInfo too early!";
298 return emptyNameEnv } }
299 -- cg_info_ref will be filled in just after restOfCodeGeneration
300 -- Meanwhile, tidyCorePgm is careful not to look at cg_info!
302 ; (pcs_simpl, tidy_details)
304 tidyCorePgm dflags this_mod pcs_middle cg_info simpl_details
306 ; pcs_final <- if ghci_mode == OneShot then initPersistentCompilerState
307 else return pcs_simpl
309 -- alive at this point:
313 ; emitExternalCore dflags new_iface tidy_details
315 ; let final_details = tidy_details {md_binds = []}
316 ; final_details `seq` return ()
319 -- PREPARE FOR CODE GENERATION
321 -- Do saturation and convert to A-normal form
322 ; prepd_details <- _scc_ "CorePrep"
323 corePrepPgm dflags tidy_details
326 -- CONVERT TO STG and COMPLETE CODE GENERATION
329 ModDetails{md_binds=binds, md_types=env_tc} = prepd_details
331 local_tycons = typeEnvTyCons env_tc
332 local_classes = typeEnvClasses env_tc
334 imported_module_names = map ideclName (hsModuleImports rdr_module)
336 mod_name_to_Module nm
337 = do m <- findModule nm ; return (fst (fromJust m))
339 (h_code, c_code, headers, fe_binders) = foreign_stuff
341 -- turn the list of headers requested in foreign import
342 -- declarations into a string suitable for emission into generated
347 . map (\fname -> "#include \"" ++ _UNPK_ fname ++ "\"")
351 -- ...and add the string to the headers requested via command line
354 ; fhdrs <- readIORef v_HCHeader
355 ; writeIORef v_HCHeader (fhdrs ++ foreign_headers)
357 ; imported_modules <- mapM mod_name_to_Module imported_module_names
359 ; (stub_h_exists, stub_c_exists, maybe_bcos, final_iface )
363 ----------------- Generate byte code ------------------
364 (bcos,itbl_env) <- byteCodeGen dflags binds
365 local_tycons local_classes
367 -- Fill in the code-gen info
368 writeIORef cg_info_ref (Just emptyNameEnv)
370 ------------------ BUILD THE NEW ModIface ------------
371 final_iface <- _scc_ "MkFinalIface"
372 mkFinalIface ghci_mode dflags location
373 maybe_checked_iface new_iface tidy_details
375 return ( False, False, Just (bcos,itbl_env), final_iface )
377 then error "GHC not compiled with interpreter"
381 ----------------- Convert to STG ------------------
382 (stg_binds, cost_centre_info, stg_back_end_info)
384 myCoreToStg dflags this_mod binds
386 -- Fill in the code-gen info for the earlier tidyCorePgm
387 writeIORef cg_info_ref (Just stg_back_end_info)
389 ------------------ BUILD THE NEW ModIface ------------
390 final_iface <- _scc_ "MkFinalIface"
391 mkFinalIface ghci_mode dflags location
392 maybe_checked_iface new_iface tidy_details
395 return (False, False, Nothing, final_iface)
397 ------------------ Code generation ------------------
398 abstractC <- _scc_ "CodeGen"
399 codeGen dflags this_mod imported_modules
400 cost_centre_info fe_binders
401 local_tycons stg_binds
403 ------------------ Code output -----------------------
404 (stub_h_exists, stub_c_exists)
405 <- codeOutput dflags this_mod [] --local_tycons
407 c_code h_code abstractC
409 return (stub_h_exists, stub_c_exists, Nothing, final_iface)
411 -- and the answer is ...
412 ; return (HscRecomp pcs_final
415 stub_h_exists stub_c_exists
419 myParseModule dflags src_filename
420 = do -------------------------- Parser ----------------
421 showPass dflags "Parser"
424 buf <- hGetStringBuffer True{-expand tabs-} src_filename
426 let glaexts | dopt Opt_GlasgowExts dflags = 1#
429 case parseModule buf PState{ bol = 0#, atbol = 1#,
430 context = [], glasgow_exts = glaexts,
431 loc = mkSrcLoc (_PK_ src_filename) 1 } of {
433 PFailed err -> do { hPutStrLn stderr (showSDoc err);
434 freeStringBuffer buf;
437 POk _ rdr_module@(HsModule mod_name _ _ _ _ _ _) -> do {
439 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_module) ;
441 dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics"
442 (ppSourceStats False rdr_module) ;
444 return (Just rdr_module)
445 -- ToDo: free the string buffer later.
449 myCoreToStg dflags this_mod tidy_binds
451 () <- coreBindsSize tidy_binds `seq` return ()
452 -- TEMP: the above call zaps some space usage allocated by the
453 -- simplifier, which for reasons I don't understand, persists
454 -- thoroughout code generation -- JRS
456 -- This is still necessary. -- SDM (10 Dec 2001)
458 stg_binds <- _scc_ "Core2Stg"
459 coreToStg dflags tidy_binds
461 (stg_binds2, cost_centre_info) <- _scc_ "Core2Stg"
462 stg2stg dflags this_mod stg_binds
464 let env_rhs :: CgInfoEnv
465 env_rhs = mkNameEnv [ caf_info `seq` (idName bndr, CgInfo caf_info)
466 | (bind,_) <- stg_binds2,
468 | stgBindHasCafRefs bind = MayHaveCafRefs
469 | otherwise = NoCafRefs,
470 bndr <- stgBinders bind ]
472 return (stg_binds2, cost_centre_info, env_rhs)
476 %************************************************************************
478 \subsection{Compiling a do-statement}
480 %************************************************************************
488 -> PersistentCompilerState -- IN: persistent compiler state
489 -> InteractiveContext -- Context for compiling
490 -> String -- The statement
491 -> Bool -- just treat it as an expression
492 -> IO ( PersistentCompilerState,
498 When the UnlinkedBCOExpr is linked you get an HValue of type
500 When you run it you get a list of HValues that should be
501 the same length as the list of names; add them to the ClosureEnv.
503 A naked expression returns a singleton Name [it].
505 What you type The IO [HValue] that hscStmt returns
506 ------------- ------------------------------------
507 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
510 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
513 expr (of IO type) ==> expr >>= \ v -> return [v]
514 [NB: result not printed] bindings: [it]
517 expr (of non-IO type,
518 result showable) ==> let v = expr in print v >> return [v]
521 expr (of non-IO type,
522 result not showable) ==> error
525 hscStmt dflags hst hit pcs0 icontext stmt just_expr
526 = do { maybe_stmt <- hscParseStmt dflags stmt
528 Nothing -> return (pcs0, Nothing)
529 Just parsed_stmt -> do {
531 let { notExprStmt (ExprStmt _ _ _) = False;
535 if (just_expr && notExprStmt parsed_stmt)
536 then do hPutStrLn stderr ("not an expression: `" ++ stmt ++ "'")
537 return (pcs0, Nothing)
541 (pcs1, print_unqual, maybe_renamed_stmt)
542 <- renameStmt dflags hit hst pcs0 icontext parsed_stmt
544 ; case maybe_renamed_stmt of
545 Nothing -> return (pcs0, Nothing)
546 Just (bound_names, rn_stmt) -> do {
551 then case rn_stmt of { (ExprStmt e _ _, decls) ->
552 typecheckExpr dflags pcs1 hst (ic_type_env icontext)
553 print_unqual iNTERACTIVE (e,decls) }
554 else typecheckStmt dflags pcs1 hst (ic_type_env icontext)
555 print_unqual iNTERACTIVE bound_names rn_stmt
557 ; case maybe_tc_return of
558 Nothing -> return (pcs0, Nothing)
559 Just (pcs2, tc_expr, bound_ids, ty) -> do {
562 ds_expr <- deSugarExpr dflags pcs2 hst iNTERACTIVE print_unqual tc_expr
565 ; simpl_expr <- simplifyExpr dflags pcs2 hst ds_expr
567 -- Tidy it (temporary, until coreSat does cloning)
568 ; tidy_expr <- tidyCoreExpr simpl_expr
570 -- Prepare for codegen
571 ; prepd_expr <- corePrepExpr dflags tidy_expr
574 ; bcos <- coreExprToBCOs dflags prepd_expr
577 -- Make all the bound ids "global" ids, now that
578 -- they're notionally top-level bindings. This is
579 -- important: otherwise when we come to compile an expression
580 -- using these ids later, the byte code generator will consider
581 -- the occurrences to be free rather than global.
582 global_bound_ids = map globaliseId bound_ids;
583 globaliseId id = setGlobalIdDetails id VanillaGlobal
585 ; return (pcs2, Just (global_bound_ids, ty, bcos))
589 hscParseStmt :: DynFlags -> String -> IO (Maybe RdrNameStmt)
590 hscParseStmt dflags str
591 = do -------------------------- Parser ----------------
592 showPass dflags "Parser"
595 buf <- stringToStringBuffer str
597 let glaexts | dopt Opt_GlasgowExts dflags = 1#
600 case parseStmt buf PState{ bol = 0#, atbol = 1#,
601 context = [], glasgow_exts = glaexts,
602 loc = mkSrcLoc SLIT("<interactive>") 1 } of {
604 PFailed err -> do { hPutStrLn stderr (showSDoc err);
605 -- Not yet implemented in <4.11 freeStringBuffer buf;
608 -- no stmt: the line consisted of just space or comments
609 POk _ Nothing -> return Nothing;
611 POk _ (Just rdr_stmt) -> do {
613 --ToDo: can't free the string buffer until we've finished this
614 -- compilation sweep and all the identifiers have gone away.
615 --freeStringBuffer buf;
616 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_stmt);
617 return (Just rdr_stmt)
622 %************************************************************************
624 \subsection{Getting information about an identifer}
626 %************************************************************************
630 hscThing -- like hscStmt, but deals with a single identifier
634 -> PersistentCompilerState -- IN: persistent compiler state
635 -> InteractiveContext -- Context for compiling
636 -> String -- The identifier
637 -> IO ( PersistentCompilerState,
640 hscThing dflags hst hit pcs0 ic str
641 = do maybe_rdr_name <- myParseIdentifier dflags str
642 case maybe_rdr_name of {
643 Nothing -> return (pcs0, []);
646 -- if the identifier is a constructor (begins with an
647 -- upper-case letter), then we need to consider both
648 -- constructor and type class identifiers.
650 | occNameSpace occ == dataName = [ rdr_name, tccls_name ]
651 | otherwise = [ rdr_name ]
653 occ = rdrNameOcc rdr_name
654 tccls_occ = setOccNameSpace occ tcClsName
655 tccls_name = setRdrNameOcc rdr_name tccls_occ
657 (pcs, unqual, maybe_rn_result) <-
658 renameRdrName dflags hit hst pcs0 ic rdr_names
660 case maybe_rn_result of {
661 Nothing -> return (pcs, []);
662 Just (names, decls) -> do {
664 maybe_pcs <- typecheckExtraDecls dflags pcs hst unqual
668 Nothing -> return (pcs, []);
671 | isLocalName n = lookupNameEnv (ic_type_env ic) n
672 | otherwise = lookupType hst (pcs_PTE pcs) n
674 maybe_ty_things = map do_lookup names
676 return (pcs, catMaybes maybe_ty_things) }
679 myParseIdentifier dflags str
680 = do buf <- stringToStringBuffer str
682 let glaexts | dopt Opt_GlasgowExts dflags = 1#
685 case parseIdentifier buf
686 PState{ bol = 0#, atbol = 1#,
687 context = [], glasgow_exts = glaexts,
688 loc = mkSrcLoc SLIT("<interactive>") 1 } of
690 PFailed err -> do { hPutStrLn stderr (showSDoc err);
691 freeStringBuffer buf;
694 POk _ rdr_name -> do { --should, but can't: freeStringBuffer buf;
695 return (Just rdr_name) }
699 %************************************************************************
701 \subsection{Find all the things defined in a module}
703 %************************************************************************
711 -> PersistentCompilerState -- IN: persistent compiler state
712 -> Module -- module to inspect
713 -> Bool -- grab just the exports, or the whole toplev
714 -> IO (PersistentCompilerState, Maybe [TyThing])
716 hscModuleContents dflags hst hit pcs0 mod exports_only = do {
718 -- slurp the interface if necessary
719 (pcs1, print_unqual, maybe_rn_stuff)
720 <- slurpIface dflags hit hst pcs0 mod;
722 case maybe_rn_stuff of {
723 Nothing -> return (pcs0, Nothing);
724 Just (names, rn_decls) -> do {
726 -- Typecheck the declarations
728 typecheckExtraDecls dflags pcs1 hst print_unqual iNTERACTIVE rn_decls;
731 Nothing -> return (pcs1, Nothing);
735 | exports_only = names
737 let { iface = fromJust (lookupModuleEnv hit mod);
738 env = fromJust (mi_globals iface);
739 range = rdrEnvElts env;
741 -- grab all the things from the global env that are locally def'd
742 nub [ n | elts <- range, GRE n LocalDef _ <- elts ];
746 ty_things = map (fromJust . lookupType hst pte) all_names;
750 return (pcs2, Just ty_things)
755 %************************************************************************
757 \subsection{Initial persistent state}
759 %************************************************************************
762 initPersistentCompilerState :: IO PersistentCompilerState
763 initPersistentCompilerState
764 = do prs <- initPersistentRenamerState
766 PCS { pcs_PIT = emptyIfaceTable,
767 pcs_PTE = wiredInThingEnv,
768 pcs_insts = emptyInstEnv,
769 pcs_rules = emptyRuleBase,
774 initPersistentRenamerState :: IO PersistentRenamerState
775 = do us <- mkSplitUniqSupply 'r'
777 PRS { prsOrig = NameSupply { nsUniqs = us,
778 nsNames = initOrigNames,
780 prsDecls = (emptyNameEnv, 0),
781 prsInsts = (emptyBag, 0),
782 prsRules = foldr add_rule (emptyBag, 0) builtinRules,
787 add_rule (name,rule) (rules, n_rules)
788 = (gated_decl `consBag` rules, n_rules+1)
790 gated_decl = (gate_fn, (mod, IfaceRuleOut rdr_name rule))
791 mod = nameModule name
792 rdr_name = mkRdrOrig (moduleName mod) (nameOccName name)
793 gate_fn vis_fn = vis_fn name -- Load the rule whenever name is visible
795 initOrigNames :: FiniteMap (ModuleName,OccName) Name
797 = grab knownKeyNames `plusFM` grab (map getName wiredInThings)
799 grab names = foldl add emptyFM names
801 = addToFM env (moduleName (nameModule name), nameOccName name) name