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 )
71 import DriverState ( v_HCHeader )
72 import ErrUtils ( dumpIfSet_dyn, showPass, printError )
73 import Util ( unJust )
74 import UniqSupply ( mkSplitUniqSupply )
76 import Bag ( consBag, emptyBag )
78 import HscStats ( ppSourceStats )
80 import FiniteMap ( FiniteMap, plusFM, emptyFM, addToFM )
81 import OccName ( OccName )
82 import Name ( Name, nameModule, nameOccName, getName, isGlobalName )
83 import NameEnv ( emptyNameEnv, mkNameEnv )
84 import Module ( Module )
86 import IOExts ( newIORef, readIORef, writeIORef,
90 import Maybe ( isJust, fromJust )
93 import MkExternalCore ( emitExternalCore )
97 %************************************************************************
99 \subsection{The main compiler pipeline}
101 %************************************************************************
105 -- compilation failed
106 = HscFail PersistentCompilerState -- updated PCS
107 -- concluded that it wasn't necessary
108 | HscNoRecomp PersistentCompilerState -- updated PCS
109 ModDetails -- new details (HomeSymbolTable additions)
110 ModIface -- new iface (if any compilation was done)
112 | HscRecomp PersistentCompilerState -- updated PCS
113 ModDetails -- new details (HomeSymbolTable additions)
114 ModIface -- new iface (if any compilation was done)
115 Bool -- stub_h exists
116 Bool -- stub_c exists
118 (Maybe ([UnlinkedBCO],ItblEnv)) -- interpreted code, if any
120 (Maybe ()) -- no interpreted code whatsoever
123 -- no errors or warnings; the individual passes
124 -- (parse/rename/typecheck) print messages themselves
130 -> ModuleLocation -- location info
131 -> Bool -- True <=> source unchanged
132 -> Bool -- True <=> have an object file (for msgs only)
133 -> Maybe ModIface -- old interface, if available
134 -> HomeSymbolTable -- for home module ModDetails
136 -> PersistentCompilerState -- IN: persistent compiler state
139 hscMain ghci_mode dflags mod location source_unchanged have_object
140 maybe_old_iface hst hit pcs
141 = {-# SCC "hscMain" #-}
143 showPass dflags ("Checking old interface for hs = "
144 ++ show (ml_hs_file location)
145 ++ ", hspp = " ++ show (ml_hspp_file location));
147 (pcs_ch, errs_found, (recomp_reqd, maybe_checked_iface))
148 <- _scc_ "checkOldIface"
149 checkOldIface ghci_mode dflags hit hst pcs mod (ml_hi_file location)
150 source_unchanged maybe_old_iface;
153 return (HscFail pcs_ch)
156 let no_old_iface = not (isJust maybe_checked_iface)
157 what_next | recomp_reqd || no_old_iface = hscRecomp
158 | otherwise = hscNoRecomp
160 what_next ghci_mode dflags have_object mod location
161 maybe_checked_iface hst hit pcs_ch
165 -- we definitely expect to have the old interface available
166 hscNoRecomp ghci_mode dflags have_object
167 mod location (Just old_iface) hst hit pcs_ch
168 | ghci_mode == OneShot
170 when (verbosity dflags > 0) $
171 hPutStrLn stderr "compilation IS NOT required";
172 let { bomb = panic "hscNoRecomp:OneShot" };
173 return (HscNoRecomp pcs_ch bomb bomb)
177 when (verbosity dflags >= 1) $
178 hPutStrLn stderr ("Skipping " ++
179 showModMsg have_object mod location);
182 (pcs_cl, closure_errs, cl_hs_decls)
183 <- closeIfaceDecls dflags hit hst pcs_ch old_iface ;
185 return (HscFail pcs_cl)
190 <- typecheckIface dflags pcs_cl hst old_iface cl_hs_decls;
192 case maybe_tc_result of {
193 Nothing -> return (HscFail pcs_cl);
194 Just (pcs_tc, new_details) ->
196 return (HscNoRecomp pcs_tc new_details old_iface)
199 hscRecomp ghci_mode dflags have_object
200 mod location maybe_checked_iface hst hit pcs_ch
202 -- what target are we shooting for?
203 ; let toInterp = dopt_HscLang dflags == HscInterpreted
204 ; let toNothing = dopt_HscLang dflags == HscNothing
206 ; when (ghci_mode /= OneShot && verbosity dflags >= 1) $
207 hPutStrLn stderr ("Compiling " ++
208 showModMsg (not toInterp) mod location);
213 ; maybe_parsed <- myParseModule dflags
214 (unJust "hscRecomp:hspp" (ml_hspp_file location))
215 ; case maybe_parsed of {
216 Nothing -> return (HscFail pcs_ch);
217 Just rdr_module -> do {
218 ; let this_mod = mkHomeModule (hsModuleName rdr_module)
223 ; (pcs_rn, print_unqual, maybe_rn_result)
225 renameModule dflags ghci_mode hit hst pcs_ch this_mod rdr_module
226 ; case maybe_rn_result of {
227 Nothing -> return (HscFail pcs_ch);
228 Just (dont_discard, new_iface, rn_result) -> do {
235 typecheckModule dflags pcs_rn hst print_unqual rn_result
236 ; case maybe_tc_result of {
237 Nothing -> return (HscFail pcs_ch);
238 Just (pcs_tc, tc_result) -> do {
243 ; (ds_details, foreign_stuff)
245 deSugar dflags pcs_tc hst this_mod print_unqual tc_result
248 <- _scc_ "pcs_middle"
249 if ghci_mode == OneShot
250 then do init_pcs <- initPersistentCompilerState
251 init_prs <- initPersistentRenamerState
253 rules = pcs_rules pcs_tc
254 orig_tc = prsOrig (pcs_PRS pcs_tc)
255 new_prs = init_prs{ prsOrig=orig_tc }
257 orig_tc `seq` rules `seq` new_prs `seq`
258 return init_pcs{ pcs_PRS = new_prs,
262 -- alive at this point:
273 core2core dflags pcs_middle hst dont_discard ds_details
278 ; cg_info_ref <- newIORef Nothing ;
279 ; let cg_info :: CgInfoEnv
280 cg_info = unsafePerformIO $ do {
281 maybe_cg_env <- readIORef cg_info_ref ;
283 Just env -> return env
284 Nothing -> do { printError "Urk! Looked at CgInfo too early!";
285 return emptyNameEnv } }
286 -- cg_info_ref will be filled in just after restOfCodeGeneration
287 -- Meanwhile, tidyCorePgm is careful not to look at cg_info!
289 ; (pcs_simpl, tidy_details)
291 tidyCorePgm dflags this_mod pcs_middle cg_info simpl_details
293 ; pcs_final <- if ghci_mode == OneShot then initPersistentCompilerState
294 else return pcs_simpl
296 -- alive at this point:
300 ; emitExternalCore dflags new_iface tidy_details
302 ; let final_details = tidy_details {md_binds = []}
303 ; final_details `seq` return ()
306 -- PREPARE FOR CODE GENERATION
308 -- Do saturation and convert to A-normal form
309 ; prepd_details <- _scc_ "CorePrep"
310 corePrepPgm dflags tidy_details
313 -- CONVERT TO STG and COMPLETE CODE GENERATION
316 ModDetails{md_binds=binds, md_types=env_tc} = prepd_details
318 local_tycons = typeEnvTyCons env_tc
319 local_classes = typeEnvClasses env_tc
321 imported_module_names = map ideclName (hsModuleImports rdr_module)
323 mod_name_to_Module nm
324 = do m <- findModule nm ; return (fst (fromJust m))
326 (h_code, c_code, headers, fe_binders) = foreign_stuff
328 -- turn the list of headers requested in foreign import
329 -- declarations into a string suitable for emission into generated
334 . map (\fname -> "#include \"" ++ _UNPK_ fname ++ "\"")
338 -- ...and add the string to the headers requested via command line
341 ; fhdrs <- readIORef v_HCHeader
342 ; writeIORef v_HCHeader (fhdrs ++ foreign_headers)
344 ; imported_modules <- mapM mod_name_to_Module imported_module_names
346 ; (stub_h_exists, stub_c_exists, maybe_bcos, final_iface )
350 ----------------- Generate byte code ------------------
351 (bcos,itbl_env) <- byteCodeGen dflags binds
352 local_tycons local_classes
354 -- Fill in the code-gen info
355 writeIORef cg_info_ref (Just emptyNameEnv)
357 ------------------ BUILD THE NEW ModIface ------------
358 final_iface <- _scc_ "MkFinalIface"
359 mkFinalIface ghci_mode dflags location
360 maybe_checked_iface new_iface tidy_details
362 return ( False, False, Just (bcos,itbl_env), final_iface )
364 then error "GHC not compiled with interpreter"
368 ----------------- Convert to STG ------------------
369 (stg_binds, cost_centre_info, stg_back_end_info)
371 myCoreToStg dflags this_mod binds
373 -- Fill in the code-gen info for the earlier tidyCorePgm
374 writeIORef cg_info_ref (Just stg_back_end_info)
376 ------------------ BUILD THE NEW ModIface ------------
377 final_iface <- _scc_ "MkFinalIface"
378 mkFinalIface ghci_mode dflags location
379 maybe_checked_iface new_iface tidy_details
382 return (False, False, Nothing, final_iface)
384 ------------------ Code generation ------------------
385 abstractC <- _scc_ "CodeGen"
386 codeGen dflags this_mod imported_modules
387 cost_centre_info fe_binders
388 local_tycons stg_binds
390 ------------------ Code output -----------------------
391 (stub_h_exists, stub_c_exists)
392 <- codeOutput dflags this_mod [] --local_tycons
394 c_code h_code abstractC
396 return (stub_h_exists, stub_c_exists, Nothing, final_iface)
398 -- and the answer is ...
399 ; return (HscRecomp pcs_final
402 stub_h_exists stub_c_exists
406 myParseModule dflags src_filename
407 = do -------------------------- Parser ----------------
408 showPass dflags "Parser"
411 buf <- hGetStringBuffer True{-expand tabs-} src_filename
413 let glaexts | dopt Opt_GlasgowExts dflags = 1#
416 case parseModule buf PState{ bol = 0#, atbol = 1#,
417 context = [], glasgow_exts = glaexts,
418 loc = mkSrcLoc (_PK_ src_filename) 1 } of {
420 PFailed err -> do { hPutStrLn stderr (showSDoc err);
421 freeStringBuffer buf;
424 POk _ rdr_module@(HsModule mod_name _ _ _ _ _ _) -> do {
426 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_module) ;
428 dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics"
429 (ppSourceStats False rdr_module) ;
431 return (Just rdr_module)
432 -- ToDo: free the string buffer later.
436 myCoreToStg dflags this_mod tidy_binds
438 () <- coreBindsSize tidy_binds `seq` return ()
439 -- TEMP: the above call zaps some space usage allocated by the
440 -- simplifier, which for reasons I don't understand, persists
441 -- thoroughout code generation -- JRS
443 -- This is still necessary. -- SDM (10 Dec 2001)
445 stg_binds <- _scc_ "Core2Stg"
446 coreToStg dflags tidy_binds
448 (stg_binds2, cost_centre_info) <- _scc_ "Core2Stg"
449 stg2stg dflags this_mod stg_binds
451 let env_rhs :: CgInfoEnv
452 env_rhs = mkNameEnv [ caf_info `seq` (idName bndr, CgInfo caf_info)
453 | (bind,_) <- stg_binds2,
455 | stgBindHasCafRefs bind = MayHaveCafRefs
456 | otherwise = NoCafRefs,
457 bndr <- stgBinders bind ]
459 return (stg_binds2, cost_centre_info, env_rhs)
463 %************************************************************************
465 \subsection{Compiling a do-statement}
467 %************************************************************************
475 -> PersistentCompilerState -- IN: persistent compiler state
476 -> InteractiveContext -- Context for compiling
477 -> String -- The statement
478 -> Bool -- just treat it as an expression
479 -> IO ( PersistentCompilerState,
485 When the UnlinkedBCOExpr is linked you get an HValue of type
487 When you run it you get a list of HValues that should be
488 the same length as the list of names; add them to the ClosureEnv.
490 A naked expression returns a singleton Name [it].
492 What you type The IO [HValue] that hscStmt returns
493 ------------- ------------------------------------
494 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
497 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
500 expr (of IO type) ==> expr >>= \ v -> return [v]
501 [NB: result not printed] bindings: [it]
504 expr (of non-IO type,
505 result showable) ==> let v = expr in print v >> return [v]
508 expr (of non-IO type,
509 result not showable) ==> error
512 hscStmt dflags hst hit pcs0 icontext stmt just_expr
513 = do { maybe_stmt <- hscParseStmt dflags stmt
515 Nothing -> return (pcs0, Nothing)
516 Just parsed_stmt -> do {
518 let { notExprStmt (ExprStmt _ _ _) = False;
522 if (just_expr && notExprStmt parsed_stmt)
523 then do hPutStrLn stderr ("not an expression: `" ++ stmt ++ "'")
524 return (pcs0, Nothing)
528 (pcs1, print_unqual, maybe_renamed_stmt)
529 <- renameStmt dflags hit hst pcs0 icontext parsed_stmt
531 ; case maybe_renamed_stmt of
532 Nothing -> return (pcs0, Nothing)
533 Just (bound_names, rn_stmt) -> do {
538 then case rn_stmt of { (ExprStmt e _ _, decls) ->
539 typecheckExpr dflags pcs1 hst (ic_type_env icontext)
540 print_unqual iNTERACTIVE (e,decls) }
541 else typecheckStmt dflags pcs1 hst (ic_type_env icontext)
542 print_unqual iNTERACTIVE bound_names rn_stmt
544 ; case maybe_tc_return of
545 Nothing -> return (pcs0, Nothing)
546 Just (pcs2, tc_expr, bound_ids, ty) -> do {
549 ds_expr <- deSugarExpr dflags pcs2 hst iNTERACTIVE print_unqual tc_expr
552 ; simpl_expr <- simplifyExpr dflags pcs2 hst ds_expr
554 -- Tidy it (temporary, until coreSat does cloning)
555 ; tidy_expr <- tidyCoreExpr simpl_expr
557 -- Prepare for codegen
558 ; prepd_expr <- corePrepExpr dflags tidy_expr
561 ; bcos <- coreExprToBCOs dflags prepd_expr
564 -- Make all the bound ids "global" ids, now that
565 -- they're notionally top-level bindings. This is
566 -- important: otherwise when we come to compile an expression
567 -- using these ids later, the byte code generator will consider
568 -- the occurrences to be free rather than global.
569 global_bound_ids = map globaliseId bound_ids;
570 globaliseId id = setGlobalIdDetails id VanillaGlobal
572 ; return (pcs2, Just (global_bound_ids, ty, bcos))
576 hscParseStmt :: DynFlags -> String -> IO (Maybe RdrNameStmt)
577 hscParseStmt dflags str
578 = do -------------------------- Parser ----------------
579 showPass dflags "Parser"
582 buf <- stringToStringBuffer str
584 let glaexts | dopt Opt_GlasgowExts dflags = 1#
587 case parseStmt buf PState{ bol = 0#, atbol = 1#,
588 context = [], glasgow_exts = glaexts,
589 loc = mkSrcLoc SLIT("<interactive>") 1 } of {
591 PFailed err -> do { hPutStrLn stderr (showSDoc err);
592 -- Not yet implemented in <4.11 freeStringBuffer buf;
595 -- no stmt: the line consisted of just space or comments
596 POk _ Nothing -> return Nothing;
598 POk _ (Just rdr_stmt) -> do {
600 --ToDo: can't free the string buffer until we've finished this
601 -- compilation sweep and all the identifiers have gone away.
602 --freeStringBuffer buf;
603 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_stmt);
604 return (Just rdr_stmt)
609 %************************************************************************
611 \subsection{Getting information about an identifer}
613 %************************************************************************
617 hscThing -- like hscStmt, but deals with a single identifier
621 -> PersistentCompilerState -- IN: persistent compiler state
622 -> InteractiveContext -- Context for compiling
623 -> String -- The identifier
624 -> IO ( PersistentCompilerState,
627 hscThing dflags hst hit pcs0 ic str
628 = do maybe_rdr_name <- myParseIdentifier dflags str
629 case maybe_rdr_name of {
630 Nothing -> return (pcs0, []);
633 -- if the identifier is a constructor (begins with an
634 -- upper-case letter), then we need to consider both
635 -- constructor and type class identifiers.
637 | occNameSpace occ == dataName = [ rdr_name, tccls_name ]
638 | otherwise = [ rdr_name ]
640 occ = rdrNameOcc rdr_name
641 tccls_occ = setOccNameSpace occ tcClsName
642 tccls_name = setRdrNameOcc rdr_name tccls_occ
644 (pcs, unqual, maybe_rn_result) <-
645 renameRdrName dflags hit hst pcs0 ic rdr_names
647 case maybe_rn_result of {
648 Nothing -> return (pcs, []);
649 Just (names, decls) -> do {
651 maybe_pcs <- typecheckExtraDecls dflags pcs hst unqual
655 Nothing -> return (pcs, []);
658 | isLocalName n = lookupNameEnv (ic_type_env ic) n
659 | otherwise = lookupType hst (pcs_PTE pcs) n
661 maybe_ty_things = map do_lookup names
663 return (pcs, catMaybes maybe_ty_things) }
666 myParseIdentifier dflags str
667 = do buf <- stringToStringBuffer str
669 let glaexts | dopt Opt_GlasgowExts dflags = 1#
672 case parseIdentifier buf
673 PState{ bol = 0#, atbol = 1#,
674 context = [], glasgow_exts = glaexts,
675 loc = mkSrcLoc SLIT("<interactive>") 1 } of
677 PFailed err -> do { hPutStrLn stderr (showSDoc err);
678 freeStringBuffer buf;
681 POk _ rdr_name -> do { --should, but can't: freeStringBuffer buf;
682 return (Just rdr_name) }
686 %************************************************************************
688 \subsection{Find all the things defined in a module}
690 %************************************************************************
698 -> PersistentCompilerState -- IN: persistent compiler state
699 -> Module -- module to inspect
700 -> Bool -- grab just the exports, or the whole toplev
701 -> IO (PersistentCompilerState, Maybe [TyThing])
703 hscModuleContents dflags hst hit pcs0 mod exports_only = do {
705 -- slurp the interface if necessary
706 (pcs1, print_unqual, maybe_rn_stuff)
707 <- slurpIface dflags hit hst pcs0 mod;
709 case maybe_rn_stuff of {
710 Nothing -> return (pcs0, Nothing);
711 Just (names, rn_decls) -> do {
713 -- Typecheck the declarations
715 typecheckExtraDecls dflags pcs1 hst print_unqual iNTERACTIVE rn_decls;
718 Nothing -> return (pcs1, Nothing);
722 | exports_only = names
724 let { iface = fromJust (lookupModuleEnv hit mod);
725 env = fromJust (mi_globals iface);
726 range = rdrEnvElts env;
728 -- grab all the things from the global env that are locally def'd
729 nub [ n | elts <- range, GRE n LocalDef _ <- elts ];
733 ty_things = map (fromJust . lookupType hst pte) all_names;
737 return (pcs2, Just ty_things)
742 %************************************************************************
744 \subsection{Initial persistent state}
746 %************************************************************************
749 initPersistentCompilerState :: IO PersistentCompilerState
750 initPersistentCompilerState
751 = do prs <- initPersistentRenamerState
753 PCS { pcs_PIT = emptyIfaceTable,
754 pcs_PTE = wiredInThingEnv,
755 pcs_insts = emptyInstEnv,
756 pcs_rules = emptyRuleBase,
761 initPersistentRenamerState :: IO PersistentRenamerState
762 = do us <- mkSplitUniqSupply 'r'
764 PRS { prsOrig = NameSupply { nsUniqs = us,
765 nsNames = initOrigNames,
767 prsDecls = (emptyNameEnv, 0),
768 prsInsts = (emptyBag, 0),
769 prsRules = foldr add_rule (emptyBag, 0) builtinRules,
774 add_rule (name,rule) (rules, n_rules)
775 = (gated_decl `consBag` rules, n_rules+1)
777 gated_decl = (gate_fn, (mod, IfaceRuleOut rdr_name rule))
778 mod = nameModule name
779 rdr_name = mkRdrOrig (moduleName mod) (nameOccName name)
780 gate_fn vis_fn = vis_fn name -- Load the rule whenever name is visible
782 initOrigNames :: FiniteMap (ModuleName,OccName) Name
784 = grab knownKeyNames `plusFM` grab (map getName wiredInThings)
786 grab names = foldl add emptyFM names
788 = addToFM env (moduleName (nameModule name), nameOccName name) name