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 TidyPgm ( 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 ( isInternalName )
30 import NameEnv ( lookupNameEnv )
31 import Module ( lookupModuleEnv )
32 import RdrName ( rdrEnvElts )
33 import PrelNames ( iNTERACTIVE )
34 import StringBuffer ( stringToStringBuffer )
35 import Maybes ( catMaybes )
42 import RdrName ( mkRdrOrig )
44 import IdInfo ( CafInfo(..), CgInfoEnv, CgInfo(..) )
45 import StringBuffer ( hGetStringBuffer, freeStringBuffer )
47 import Lex ( ParseResult(..), ExtFlags(..), mkPState )
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, gHC_PRIM_Name )
55 import MkIface ( mkFinalIface )
57 import InstEnv ( emptyInstEnv )
59 import Flattening ( flatten, flattenExpr )
61 import CoreUtils ( coreBindsSize )
62 import TidyPgm ( tidyCorePgm )
63 import CorePrep ( corePrepPgm )
65 import CoreToStg ( coreToStg )
66 import SimplStg ( stg2stg )
67 import CodeGen ( codeGen )
68 import CodeOutput ( codeOutput, outputForeignStubs )
70 import Module ( ModuleName, moduleName, mkHomeModule )
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 )
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_unqual, maybe_rn_result)
226 renameModule dflags ghci_mode hit hst pcs_ch this_mod rdr_module
227 ; case maybe_rn_result of {
228 Nothing -> return (HscFail pcs_ch);
229 Just (dont_discard, new_iface, rn_result) -> do {
236 typecheckModule dflags pcs_rn hst print_unqual rn_result
237 ; case maybe_tc_result of {
238 Nothing -> return (HscFail pcs_ch);
239 Just (pcs_tc, tc_result) -> do {
244 ; (ds_details, foreign_stuff)
246 deSugar dflags pcs_tc hst this_mod print_unqual tc_result
252 <- _scc_ "Flattening"
253 flatten dflags pcs_tc hst ds_details
256 <- _scc_ "pcs_middle"
257 if ghci_mode == OneShot
258 then do init_pcs <- initPersistentCompilerState
259 init_prs <- initPersistentRenamerState
261 rules = pcs_rules pcs_tc
262 orig_tc = prsOrig (pcs_PRS pcs_tc)
263 new_prs = init_prs{ prsOrig=orig_tc }
265 orig_tc `seq` rules `seq` new_prs `seq`
266 return init_pcs{ pcs_PRS = new_prs,
270 -- alive at this point:
281 core2core dflags pcs_middle hst dont_discard flat_details
286 ; cg_info_ref <- newIORef Nothing ;
287 ; let cg_info :: CgInfoEnv
288 cg_info = unsafePerformIO $ do {
289 maybe_cg_env <- readIORef cg_info_ref ;
291 Just env -> return env
292 Nothing -> do { printError "Urk! Looked at CgInfo too early!";
293 return emptyNameEnv } }
294 -- cg_info_ref will be filled in just after restOfCodeGeneration
295 -- Meanwhile, tidyCorePgm is careful not to look at cg_info!
297 ; (pcs_simpl, tidy_details)
299 tidyCorePgm dflags this_mod pcs_middle cg_info simpl_details
301 ; pcs_final <- if ghci_mode == OneShot then initPersistentCompilerState
302 else return pcs_simpl
304 -- alive at this point:
308 ; emitExternalCore dflags new_iface tidy_details
310 ; let final_details = tidy_details {md_binds = []}
311 ; final_details `seq` return ()
314 -- PREPARE FOR CODE GENERATION
316 -- Do saturation and convert to A-normal form
317 ; prepd_details <- _scc_ "CorePrep"
318 corePrepPgm dflags tidy_details
321 -- CONVERT TO STG and COMPLETE CODE GENERATION
324 ModDetails{md_binds=binds, md_types=env_tc} = prepd_details
326 local_tycons = typeEnvTyCons env_tc
327 local_classes = typeEnvClasses env_tc
329 imported_module_names =
330 filter (/= gHC_PRIM_Name) $
331 map ideclName (hsModuleImports rdr_module)
332 -- eek! doesn't this keep rdr_module live until code generation?
335 mod_name_to_Module nm
336 = do m <- findModule nm ; return (fst (fromJust m))
338 (h_code, c_code, headers, fe_binders) = foreign_stuff
340 -- turn the list of headers requested in foreign import
341 -- declarations into a string suitable for emission into generated
346 . map (\fname -> "#include \"" ++ _UNPK_ fname ++ "\"")
350 -- ...and add the string to the headers requested via command line
353 ; fhdrs <- readIORef v_HCHeader
354 ; writeIORef v_HCHeader (fhdrs ++ foreign_headers)
356 ; imported_modules <- mapM mod_name_to_Module imported_module_names
358 ; (stub_h_exists, stub_c_exists, maybe_bcos, final_iface )
362 ----------------- Generate byte code ------------------
363 (bcos,itbl_env) <- byteCodeGen dflags binds
364 local_tycons local_classes
366 -- Fill in the code-gen info
367 writeIORef cg_info_ref (Just emptyNameEnv)
369 ------------------ BUILD THE NEW ModIface ------------
370 final_iface <- _scc_ "MkFinalIface"
371 mkFinalIface ghci_mode dflags location
372 maybe_checked_iface new_iface tidy_details
374 ------------------ Create f-x-dynamic C-side stuff ---
375 (istub_h_exists, istub_c_exists)
376 <- outputForeignStubs dflags c_code h_code
378 return ( istub_h_exists, istub_c_exists,
379 Just (bcos,itbl_env), final_iface )
381 then error "GHC not compiled with interpreter"
385 ----------------- Convert to STG ------------------
386 (stg_binds, cost_centre_info, stg_back_end_info)
388 myCoreToStg dflags this_mod binds
390 -- Fill in the code-gen info for the earlier tidyCorePgm
391 writeIORef cg_info_ref (Just stg_back_end_info)
393 ------------------ BUILD THE NEW ModIface ------------
394 final_iface <- _scc_ "MkFinalIface"
395 mkFinalIface ghci_mode dflags location
396 maybe_checked_iface new_iface tidy_details
399 return (False, False, Nothing, final_iface)
401 ------------------ Code generation ------------------
402 abstractC <- _scc_ "CodeGen"
403 codeGen dflags this_mod imported_modules
404 cost_centre_info fe_binders
405 local_tycons stg_binds
407 ------------------ Code output -----------------------
408 (stub_h_exists, stub_c_exists)
409 <- codeOutput dflags this_mod [] --local_tycons
411 c_code h_code abstractC
413 return (stub_h_exists, stub_c_exists, Nothing, final_iface)
415 -- and the answer is ...
416 ; return (HscRecomp pcs_final
419 stub_h_exists stub_c_exists
423 myParseModule dflags src_filename
424 = do -------------------------- Parser ----------------
425 showPass dflags "Parser"
428 buf <- hGetStringBuffer src_filename
430 let exts = ExtFlags {glasgowExtsEF = dopt Opt_GlasgowExts dflags,
431 parrEF = dopt Opt_PArr dflags}
432 loc = mkSrcLoc (_PK_ src_filename) 1
434 case parseModule buf (mkPState loc exts) of {
436 PFailed err -> do { hPutStrLn stderr (showSDoc err);
437 freeStringBuffer buf;
440 POk _ rdr_module@(HsModule mod_name _ _ _ _ _ _) -> do {
442 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_module) ;
444 dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics"
445 (ppSourceStats False rdr_module) ;
447 return (Just rdr_module)
448 -- ToDo: free the string buffer later.
452 myCoreToStg dflags this_mod tidy_binds
454 () <- coreBindsSize tidy_binds `seq` return ()
455 -- TEMP: the above call zaps some space usage allocated by the
456 -- simplifier, which for reasons I don't understand, persists
457 -- thoroughout code generation -- JRS
459 -- This is still necessary. -- SDM (10 Dec 2001)
461 stg_binds <- _scc_ "Core2Stg"
462 coreToStg dflags tidy_binds
464 (stg_binds2, cost_centre_info) <- _scc_ "Core2Stg"
465 stg2stg dflags this_mod stg_binds
467 let env_rhs :: CgInfoEnv
468 env_rhs = mkNameEnv [ caf_info `seq` (idName bndr, CgInfo caf_info)
469 | (bind,_) <- stg_binds2,
471 | stgBindHasCafRefs bind = MayHaveCafRefs
472 | otherwise = NoCafRefs,
473 bndr <- stgBinders bind ]
475 return (stg_binds2, cost_centre_info, env_rhs)
479 %************************************************************************
481 \subsection{Compiling a do-statement}
483 %************************************************************************
491 -> PersistentCompilerState -- IN: persistent compiler state
492 -> InteractiveContext -- Context for compiling
493 -> String -- The statement
494 -> Bool -- just treat it as an expression
495 -> IO ( PersistentCompilerState,
501 When the UnlinkedBCOExpr is linked you get an HValue of type
503 When you run it you get a list of HValues that should be
504 the same length as the list of names; add them to the ClosureEnv.
506 A naked expression returns a singleton Name [it].
508 What you type The IO [HValue] that hscStmt returns
509 ------------- ------------------------------------
510 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
513 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
516 expr (of IO type) ==> expr >>= \ v -> return [v]
517 [NB: result not printed] bindings: [it]
520 expr (of non-IO type,
521 result showable) ==> let v = expr in print v >> return [v]
524 expr (of non-IO type,
525 result not showable) ==> error
528 hscStmt dflags hst hit pcs0 icontext stmt just_expr
529 = do { maybe_stmt <- hscParseStmt dflags stmt
531 Nothing -> return (pcs0, Nothing)
532 Just parsed_stmt -> do {
534 let { notExprStmt (ExprStmt _ _ _) = False;
538 if (just_expr && notExprStmt parsed_stmt)
539 then do hPutStrLn stderr ("not an expression: `" ++ stmt ++ "'")
540 return (pcs0, Nothing)
544 (pcs1, print_unqual, maybe_renamed_stmt)
545 <- renameStmt dflags hit hst pcs0 icontext parsed_stmt
547 ; case maybe_renamed_stmt of
548 Nothing -> return (pcs0, Nothing)
549 Just (bound_names, rn_stmt) -> do {
554 then case rn_stmt of { (ExprStmt e _ _, decls) ->
555 typecheckExpr dflags pcs1 hst (ic_type_env icontext)
556 print_unqual iNTERACTIVE (e,decls) }
557 else typecheckStmt dflags pcs1 hst (ic_type_env icontext)
558 print_unqual iNTERACTIVE bound_names rn_stmt
560 ; case maybe_tc_return of
561 Nothing -> return (pcs0, Nothing)
562 Just (pcs2, tc_expr, bound_ids, ty) -> do {
565 ds_expr <- deSugarExpr dflags pcs2 hst iNTERACTIVE print_unqual tc_expr
568 ; flat_expr <- flattenExpr dflags pcs2 hst ds_expr
571 ; simpl_expr <- simplifyExpr dflags pcs2 hst flat_expr
573 -- Tidy it (temporary, until coreSat does cloning)
574 ; tidy_expr <- tidyCoreExpr simpl_expr
576 -- Prepare for codegen
577 ; prepd_expr <- corePrepExpr dflags tidy_expr
580 ; bcos <- coreExprToBCOs dflags prepd_expr
583 -- Make all the bound ids "global" ids, now that
584 -- they're notionally top-level bindings. This is
585 -- important: otherwise when we come to compile an expression
586 -- using these ids later, the byte code generator will consider
587 -- the occurrences to be free rather than global.
588 global_bound_ids = map globaliseId bound_ids;
589 globaliseId id = setGlobalIdDetails id VanillaGlobal
591 ; return (pcs2, Just (global_bound_ids, ty, bcos))
595 hscParseStmt :: DynFlags -> String -> IO (Maybe RdrNameStmt)
596 hscParseStmt dflags str
597 = do -------------------------- Parser ----------------
598 showPass dflags "Parser"
601 buf <- stringToStringBuffer str
603 let exts = ExtFlags {glasgowExtsEF = dopt Opt_GlasgowExts dflags,
604 parrEF = dopt Opt_PArr dflags}
605 loc = mkSrcLoc SLIT("<interactive>") 1
607 case parseStmt buf (mkPState loc exts) of {
609 PFailed err -> do { hPutStrLn stderr (showSDoc err);
610 -- Not yet implemented in <4.11 freeStringBuffer buf;
613 -- no stmt: the line consisted of just space or comments
614 POk _ Nothing -> return Nothing;
616 POk _ (Just rdr_stmt) -> do {
618 --ToDo: can't free the string buffer until we've finished this
619 -- compilation sweep and all the identifiers have gone away.
620 --freeStringBuffer buf;
621 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_stmt);
622 return (Just rdr_stmt)
627 %************************************************************************
629 \subsection{Getting information about an identifer}
631 %************************************************************************
635 hscThing -- like hscStmt, but deals with a single identifier
639 -> PersistentCompilerState -- IN: persistent compiler state
640 -> InteractiveContext -- Context for compiling
641 -> String -- The identifier
642 -> IO ( PersistentCompilerState,
645 hscThing dflags hst hit pcs0 ic str
646 = do maybe_rdr_name <- myParseIdentifier dflags str
647 case maybe_rdr_name of {
648 Nothing -> return (pcs0, []);
651 -- if the identifier is a constructor (begins with an
652 -- upper-case letter), then we need to consider both
653 -- constructor and type class identifiers.
655 | occNameSpace occ == dataName = [ rdr_name, tccls_name ]
656 | otherwise = [ rdr_name ]
658 occ = rdrNameOcc rdr_name
659 tccls_occ = setOccNameSpace occ tcClsName
660 tccls_name = setRdrNameOcc rdr_name tccls_occ
662 (pcs, unqual, maybe_rn_result) <-
663 renameRdrName dflags hit hst pcs0 ic rdr_names
665 case maybe_rn_result of {
666 Nothing -> return (pcs, []);
667 Just (names, decls) -> do {
669 maybe_pcs <- typecheckExtraDecls dflags pcs hst unqual
673 Nothing -> return (pcs, []);
676 | isInternalName n = lookupNameEnv (ic_type_env ic) n
677 | otherwise = lookupType hst (pcs_PTE pcs) n
679 maybe_ty_things = map do_lookup names
681 return (pcs, catMaybes maybe_ty_things) }
684 myParseIdentifier dflags str
685 = do buf <- stringToStringBuffer str
687 let exts = ExtFlags {glasgowExtsEF = dopt Opt_GlasgowExts dflags,
688 parrEF = dopt Opt_PArr dflags}
689 loc = mkSrcLoc SLIT("<interactive>") 1
691 case parseIdentifier buf (mkPState loc exts) of
693 PFailed err -> do { hPutStrLn stderr (showSDoc err);
694 freeStringBuffer buf;
697 POk _ rdr_name -> do { --should, but can't: freeStringBuffer buf;
698 return (Just rdr_name) }
702 %************************************************************************
704 \subsection{Find all the things defined in a module}
706 %************************************************************************
714 -> PersistentCompilerState -- IN: persistent compiler state
715 -> Module -- module to inspect
716 -> Bool -- grab just the exports, or the whole toplev
717 -> IO (PersistentCompilerState, Maybe [TyThing])
719 hscModuleContents dflags hst hit pcs0 mod exports_only = do {
721 -- slurp the interface if necessary
722 (pcs1, print_unqual, maybe_rn_stuff)
723 <- slurpIface dflags hit hst pcs0 mod;
725 case maybe_rn_stuff of {
726 Nothing -> return (pcs0, Nothing);
727 Just (names, rn_decls) -> do {
729 -- Typecheck the declarations
731 typecheckExtraDecls dflags pcs1 hst print_unqual iNTERACTIVE rn_decls;
734 Nothing -> return (pcs1, Nothing);
738 | exports_only = names
740 let { iface = fromJust (lookupModuleEnv hit mod);
741 env = fromJust (mi_globals iface);
742 range = rdrEnvElts env;
744 -- grab all the things from the global env that are locally def'd
745 nub [ n | elts <- range, GRE n LocalDef _ <- elts ];
749 ty_things = map (fromJust . lookupType hst pte) all_names;
753 return (pcs2, Just ty_things)
758 %************************************************************************
760 \subsection{Initial persistent state}
762 %************************************************************************
765 initPersistentCompilerState :: IO PersistentCompilerState
766 initPersistentCompilerState
767 = do prs <- initPersistentRenamerState
769 PCS { pcs_PIT = emptyIfaceTable,
770 pcs_PTE = wiredInThingEnv,
771 pcs_insts = emptyInstEnv,
772 pcs_rules = emptyRuleBase,
777 initPersistentRenamerState :: IO PersistentRenamerState
778 = do us <- mkSplitUniqSupply 'r'
780 PRS { prsOrig = NameSupply { nsUniqs = us,
781 nsNames = initOrigNames,
783 prsDecls = (emptyNameEnv, 0),
784 prsInsts = (emptyBag, 0),
785 prsRules = foldr add_rule (emptyBag, 0) builtinRules,
790 add_rule (name,rule) (rules, n_rules)
791 = (gated_decl `consBag` rules, n_rules+1)
793 gated_decl = (gate_fn, (mod, IfaceRuleOut rdr_name rule))
794 mod = nameModule name
795 rdr_name = mkRdrOrig (moduleName mod) (nameOccName name)
796 gate_fn vis_fn = vis_fn name -- Load the rule whenever name is visible
798 initOrigNames :: FiniteMap (ModuleName,OccName) Name
800 = grab knownKeyNames `plusFM` grab (map getName wiredInThings)
802 grab names = foldl add emptyFM names
804 = addToFM env (moduleName (nameModule name), nameOccName name) name