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,
12 initPersistentCompilerState ) where
14 #include "HsVersions.h"
17 import ByteCodeGen ( byteCodeGen )
18 import CoreTidy ( tidyCoreExpr )
19 import CorePrep ( corePrepExpr )
20 import Rename ( renameStmt, renameRdrName )
21 import RdrName ( rdrNameOcc, setRdrNameOcc )
22 import RdrHsSyn ( RdrNameStmt )
23 import OccName ( dataName, tcClsName,
24 occNameSpace, setOccNameSpace )
26 import Id ( Id, idName, setGlobalIdDetails )
27 import IdInfo ( GlobalIdDetails(VanillaGlobal) )
28 import HscTypes ( InteractiveContext(..) )
29 import PrelNames ( iNTERACTIVE )
30 import StringBuffer ( stringToStringBuffer )
31 import FastString ( mkFastString )
37 import IdInfo ( CafInfo(..), CgInfoEnv, CgInfo(..) )
38 import StringBuffer ( hGetStringBuffer, freeStringBuffer )
40 import Lex ( PState(..), ParseResult(..) )
41 import SrcLoc ( mkSrcLoc )
42 import Finder ( findModule )
43 import Rename ( checkOldIface, renameModule, closeIfaceDecls )
44 import Rules ( emptyRuleBase )
45 import PrelInfo ( wiredInThingEnv, wiredInThings )
46 import PrelNames ( knownKeyNames )
47 import MkIface ( mkFinalIface )
49 import InstEnv ( emptyInstEnv )
52 import CoreUtils ( coreBindsSize )
53 import CoreTidy ( tidyCorePgm )
54 import CorePrep ( corePrepPgm )
56 import CoreToStg ( coreToStg )
57 import SimplStg ( stg2stg )
58 import CodeGen ( codeGen )
59 import CodeOutput ( codeOutput )
61 import Module ( ModuleName, moduleName, mkHomeModule,
64 import ErrUtils ( dumpIfSet_dyn, showPass, printError )
65 import Util ( unJust )
66 import UniqSupply ( mkSplitUniqSupply )
68 import Bag ( emptyBag )
71 import HscStats ( ppSourceStats )
73 import FiniteMap ( FiniteMap, plusFM, emptyFM, addToFM )
74 import OccName ( OccName )
75 import Name ( Name, nameModule, nameOccName, getName, isGlobalName )
76 import NameEnv ( emptyNameEnv, mkNameEnv )
77 import Module ( Module )
79 import IOExts ( newIORef, readIORef, writeIORef, unsafePerformIO )
82 import Maybe ( isJust, fromJust, catMaybes )
85 import MkExternalCore ( emitExternalCore )
89 %************************************************************************
91 \subsection{The main compiler pipeline}
93 %************************************************************************
98 = HscFail PersistentCompilerState -- updated PCS
99 -- concluded that it wasn't necessary
100 | HscNoRecomp PersistentCompilerState -- updated PCS
101 ModDetails -- new details (HomeSymbolTable additions)
102 ModIface -- new iface (if any compilation was done)
104 | HscRecomp PersistentCompilerState -- updated PCS
105 ModDetails -- new details (HomeSymbolTable additions)
106 ModIface -- new iface (if any compilation was done)
107 Bool -- stub_h exists
108 Bool -- stub_c exists
110 (Maybe ([UnlinkedBCO],ItblEnv)) -- interpreted code, if any
112 (Maybe ()) -- no interpreted code whatsoever
115 -- no errors or warnings; the individual passes
116 -- (parse/rename/typecheck) print messages themselves
122 -> ModuleLocation -- location info
123 -> Bool -- True <=> source unchanged
124 -> Bool -- True <=> have an object file (for msgs only)
125 -> Maybe ModIface -- old interface, if available
126 -> HomeSymbolTable -- for home module ModDetails
128 -> PersistentCompilerState -- IN: persistent compiler state
131 hscMain ghci_mode dflags mod location source_unchanged have_object
132 maybe_old_iface hst hit pcs
134 showPass dflags ("Checking old interface for hs = "
135 ++ show (ml_hs_file location)
136 ++ ", hspp = " ++ show (ml_hspp_file location));
138 (pcs_ch, errs_found, (recomp_reqd, maybe_checked_iface))
139 <- _scc_ "checkOldIface"
140 checkOldIface ghci_mode dflags hit hst pcs (ml_hi_file location)
141 source_unchanged maybe_old_iface;
144 return (HscFail pcs_ch)
147 let no_old_iface = not (isJust maybe_checked_iface)
148 what_next | recomp_reqd || no_old_iface = hscRecomp
149 | otherwise = hscNoRecomp
151 what_next ghci_mode dflags have_object mod location
152 maybe_checked_iface hst hit pcs_ch
156 -- we definitely expect to have the old interface available
157 hscNoRecomp ghci_mode dflags have_object
158 mod location (Just old_iface) hst hit pcs_ch
159 | ghci_mode == OneShot
161 hPutStrLn stderr "compilation IS NOT required";
162 let { bomb = panic "hscNoRecomp:OneShot" };
163 return (HscNoRecomp pcs_ch bomb bomb)
167 when (verbosity dflags >= 1) $
168 hPutStrLn stderr ("Skipping " ++
169 compMsg have_object mod location);
172 (pcs_cl, closure_errs, cl_hs_decls)
173 <- closeIfaceDecls dflags hit hst pcs_ch old_iface ;
175 return (HscFail pcs_cl)
180 <- typecheckIface dflags pcs_cl hst old_iface cl_hs_decls;
182 case maybe_tc_result of {
183 Nothing -> return (HscFail pcs_cl);
184 Just (pcs_tc, new_details) ->
186 return (HscNoRecomp pcs_tc new_details old_iface)
189 compMsg use_object mod location =
190 mod_str ++ take (max 0 (16 - length mod_str)) (repeat ' ')
191 ++" ( " ++ unJust "hscRecomp" (ml_hs_file location) ++ ", "
193 then unJust "hscRecomp" (ml_obj_file location)
196 where mod_str = moduleUserString mod
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 (verbosity dflags >= 1) $
207 hPutStrLn stderr ("Compiling " ++
208 compMsg (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_unqualified, maybe_rn_result)
225 renameModule dflags hit hst pcs_ch this_mod rdr_module
226 ; case maybe_rn_result of {
227 Nothing -> return (HscFail pcs_ch{-was: pcs_rn-});
228 Just (is_exported, new_iface, rn_hs_decls) -> do {
230 -- In interactive mode, we don't want to discard any top-level entities at
231 -- all (eg. do not inline them away during simplification), and retain them
232 -- all in the TypeEnv so they are available from the command line.
234 -- isGlobalName separates the user-defined top-level names from those
235 -- introduced by the type checker.
236 ; let dont_discard | ghci_mode == Interactive = isGlobalName
237 | otherwise = is_exported
243 <- _scc_ "TypeCheck" typecheckModule dflags pcs_rn hst new_iface
244 print_unqualified rn_hs_decls
245 ; case maybe_tc_result of {
246 Nothing -> return (HscFail pcs_ch{-was: pcs_rn-});
247 Just (pcs_tc, tc_result) -> do {
252 ; (ds_details, foreign_stuff)
254 deSugar dflags pcs_tc hst this_mod print_unqualified tc_result
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,
275 core2core dflags pcs_middle hst dont_discard ds_details
280 ; cg_info_ref <- newIORef Nothing ;
281 ; let cg_info :: CgInfoEnv
282 cg_info = unsafePerformIO $ do {
283 maybe_cg_env <- readIORef cg_info_ref ;
285 Just env -> return env
286 Nothing -> do { printError "Urk! Looked at CgInfo too early!";
287 return emptyNameEnv } }
288 -- cg_info_ref will be filled in just after restOfCodeGeneration
289 -- Meanwhile, tidyCorePgm is careful not to look at cg_info!
291 ; (pcs_simpl, tidy_details)
293 tidyCorePgm dflags this_mod pcs_middle cg_info simpl_details
295 ; pcs_final <- if ghci_mode == OneShot then initPersistentCompilerState
296 else return pcs_simpl
298 -- alive at this point:
302 ; emitExternalCore dflags new_iface tidy_details
304 -- PREPARE FOR CODE GENERATION
306 -- Do saturation and convert to A-normal form
307 ; prepd_details <- _scc_ "CorePrep" corePrepPgm dflags tidy_details
310 -- CONVERT TO STG and COMPLETE CODE GENERATION
313 ModDetails{md_binds=binds, md_types=env_tc} = prepd_details
315 local_tycons = typeEnvTyCons env_tc
316 local_classes = typeEnvClasses env_tc
318 imported_module_names = map ideclName (hsModuleImports rdr_module)
320 mod_name_to_Module nm
321 = do m <- findModule nm ; return (fst (fromJust m))
323 (h_code,c_code,fe_binders) = foreign_stuff
325 ; imported_modules <- mapM mod_name_to_Module imported_module_names
327 ; (stub_h_exists, stub_c_exists, maybe_bcos, final_iface )
331 ----------------- Generate byte code ------------------
332 (bcos,itbl_env) <- byteCodeGen dflags binds
333 local_tycons local_classes
335 -- Fill in the code-gen info
336 writeIORef cg_info_ref (Just emptyNameEnv)
338 ------------------ BUILD THE NEW ModIface ------------
339 final_iface <- _scc_ "MkFinalIface"
340 mkFinalIface ghci_mode dflags location
341 maybe_checked_iface new_iface tidy_details
343 return ( False, False, Just (bcos,itbl_env), final_iface )
345 then error "GHC not compiled with interpreter"
349 ----------------- Convert to STG ------------------
350 (stg_binds, cost_centre_info, stg_back_end_info)
352 myCoreToStg dflags this_mod binds
354 -- Fill in the code-gen info for the earlier tidyCorePgm
355 writeIORef cg_info_ref (Just stg_back_end_info)
357 ------------------ BUILD THE NEW ModIface ------------
358 final_iface <- _scc_ "MkFinalIface"
359 mkFinalIface ghci_mode dflags location
360 maybe_checked_iface new_iface tidy_details
364 return (False, False, Nothing, final_iface)
366 ------------------ Code generation ------------------
367 abstractC <- _scc_ "CodeGen"
368 codeGen dflags this_mod imported_modules
369 cost_centre_info fe_binders
370 local_tycons stg_binds
372 ------------------ Code output -----------------------
373 (stub_h_exists, stub_c_exists)
374 <- codeOutput dflags this_mod local_tycons
376 c_code h_code abstractC
378 return (stub_h_exists, stub_c_exists, Nothing, final_iface)
380 ; let final_details = tidy_details {md_binds = []}
383 -- and the answer is ...
384 ; return (HscRecomp pcs_final
387 stub_h_exists stub_c_exists
391 myParseModule dflags src_filename
392 = do -------------------------- Parser ----------------
393 showPass dflags "Parser"
396 buf <- hGetStringBuffer True{-expand tabs-} src_filename
398 let glaexts | dopt Opt_GlasgowExts dflags = 1#
401 case parseModule buf PState{ bol = 0#, atbol = 1#,
402 context = [], glasgow_exts = glaexts,
403 loc = mkSrcLoc (_PK_ src_filename) 1 } of {
405 PFailed err -> do { hPutStrLn stderr (showSDoc err);
406 freeStringBuffer buf;
409 POk _ rdr_module@(HsModule mod_name _ _ _ _ _ _) -> do {
411 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_module) ;
413 dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics"
414 (ppSourceStats False rdr_module) ;
416 return (Just rdr_module)
417 -- ToDo: free the string buffer later.
421 myCoreToStg dflags this_mod tidy_binds
423 () <- coreBindsSize tidy_binds `seq` return ()
424 -- TEMP: the above call zaps some space usage allocated by the
425 -- simplifier, which for reasons I don't understand, persists
426 -- thoroughout code generation
428 stg_binds <- _scc_ "Core2Stg" coreToStg dflags tidy_binds
430 (stg_binds2, cost_centre_info)
431 <- _scc_ "Core2Stg" stg2stg dflags this_mod stg_binds
433 let env_rhs :: CgInfoEnv
434 env_rhs = mkNameEnv [ (idName bndr, CgInfo (stgRhsArity rhs) caf_info)
435 | (bind,_) <- stg_binds2,
437 | stgBindHasCafRefs bind = MayHaveCafRefs
438 | otherwise = NoCafRefs,
439 (bndr,rhs) <- stgBindPairs bind ]
441 return (stg_binds2, cost_centre_info, env_rhs)
443 stgBindPairs (StgNonRec _ b r) = [(b,r)]
444 stgBindPairs (StgRec _ prs) = prs
450 %************************************************************************
452 \subsection{Compiling a do-statement}
454 %************************************************************************
462 -> PersistentCompilerState -- IN: persistent compiler state
463 -> InteractiveContext -- Context for compiling
464 -> String -- The statement
465 -> Bool -- just treat it as an expression
466 -> IO ( PersistentCompilerState,
472 When the UnlinkedBCOExpr is linked you get an HValue of type
474 When you run it you get a list of HValues that should be
475 the same length as the list of names; add them to the ClosureEnv.
477 A naked expression returns a singleton Name [it].
479 What you type The IO [HValue] that hscStmt returns
480 ------------- ------------------------------------
481 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
484 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
487 expr (of IO type) ==> expr >>= \ v -> return [v]
488 [NB: result not printed] bindings: [it]
491 expr (of non-IO type,
492 result showable) ==> let v = expr in print v >> return [v]
495 expr (of non-IO type,
496 result not showable) ==> error
499 hscStmt dflags hst hit pcs0 icontext stmt just_expr
500 = do { maybe_stmt <- hscParseStmt dflags stmt
502 Nothing -> return (pcs0, Nothing)
503 Just parsed_stmt -> do {
505 let { notExprStmt (ExprStmt _ _ _) = False;
509 if (just_expr && notExprStmt parsed_stmt)
510 then do hPutStrLn stderr ("not an expression: `" ++ stmt ++ "'")
511 return (pcs0, Nothing)
515 (pcs1, print_unqual, maybe_renamed_stmt)
516 <- renameStmt dflags hit hst pcs0
517 iNTERACTIVE icontext parsed_stmt
519 ; case maybe_renamed_stmt of
520 Nothing -> return (pcs0, Nothing)
521 Just (bound_names, rn_stmt) -> do {
526 then case rn_stmt of { (ExprStmt e _ _, decls) ->
527 typecheckExpr dflags pcs1 hst (ic_type_env icontext)
528 print_unqual iNTERACTIVE (e,decls) }
529 else typecheckStmt dflags pcs1 hst (ic_type_env icontext)
530 print_unqual iNTERACTIVE bound_names rn_stmt
532 ; case maybe_tc_return of
533 Nothing -> return (pcs0, Nothing)
534 Just (pcs2, tc_expr, bound_ids, ty) -> do {
537 ds_expr <- deSugarExpr dflags pcs2 hst iNTERACTIVE print_unqual tc_expr
540 ; simpl_expr <- simplifyExpr dflags pcs2 hst ds_expr
542 -- Tidy it (temporary, until coreSat does cloning)
543 ; tidy_expr <- tidyCoreExpr simpl_expr
545 -- Prepare for codegen
546 ; prepd_expr <- corePrepExpr dflags tidy_expr
549 ; bcos <- coreExprToBCOs dflags prepd_expr
552 -- Make all the bound ids "global" ids, now that
553 -- they're notionally top-level bindings. This is
554 -- important: otherwise when we come to compile an expression
555 -- using these ids later, the byte code generator will consider
556 -- the occurrences to be free rather than global.
557 global_bound_ids = map globaliseId bound_ids;
558 globaliseId id = setGlobalIdDetails id VanillaGlobal
560 ; return (pcs2, Just (global_bound_ids, ty, bcos))
564 hscParseStmt :: DynFlags -> String -> IO (Maybe RdrNameStmt)
565 hscParseStmt dflags str
566 = do -------------------------- Parser ----------------
567 showPass dflags "Parser"
570 buf <- stringToStringBuffer str
572 let glaexts | dopt Opt_GlasgowExts dflags = 1#
575 case parseStmt buf PState{ bol = 0#, atbol = 1#,
576 context = [], glasgow_exts = glaexts,
577 loc = mkSrcLoc SLIT("<interactive>") 1 } of {
579 PFailed err -> do { hPutStrLn stderr (showSDoc err);
580 -- Not yet implemented in <4.11 freeStringBuffer buf;
583 -- no stmt: the line consisted of just space or comments
584 POk _ Nothing -> return Nothing;
586 POk _ (Just rdr_stmt) -> do {
588 --ToDo: can't free the string buffer until we've finished this
589 -- compilation sweep and all the identifiers have gone away.
590 --freeStringBuffer buf;
591 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_stmt);
592 return (Just rdr_stmt)
597 %************************************************************************
599 \subsection{Getting information about an identifer}
601 %************************************************************************
605 hscThing -- like hscStmt, but deals with a single identifier
609 -> PersistentCompilerState -- IN: persistent compiler state
610 -> InteractiveContext -- Context for compiling
611 -> String -- The identifier
612 -> IO ( PersistentCompilerState,
615 hscThing dflags hst hit pcs0 icontext str
616 = do maybe_rdr_name <- myParseIdentifier dflags str
617 case maybe_rdr_name of {
618 Nothing -> return (pcs0, []);
621 -- if the identifier is a constructor (begins with an
622 -- upper-case letter), then we need to consider both
623 -- constructor and type class identifiers.
625 | occNameSpace occ == dataName = [ rdr_name, tccls_name ]
626 | otherwise = [ rdr_name ]
628 occ = rdrNameOcc rdr_name
629 tccls_occ = setOccNameSpace occ tcClsName
630 tccls_name = setRdrNameOcc rdr_name tccls_occ
632 (pcs, unqual, maybe_rn_result) <-
633 renameRdrName dflags hit hst pcs0 iNTERACTIVE icontext rdr_names
635 case maybe_rn_result of {
636 Nothing -> return (pcs, []);
637 Just (names, decls) -> do {
639 maybe_pcs <- typecheckExtraDecls dflags pcs hst unqual
643 Nothing -> return (pcs, []);
645 let maybe_ty_things = map (lookupType hst (pcs_PTE pcs)) names
647 return (pcs, catMaybes maybe_ty_things) }
650 myParseIdentifier dflags str
651 = do buf <- stringToStringBuffer str
653 let glaexts | dopt Opt_GlasgowExts dflags = 1#
656 case parseIdentifier buf
657 PState{ bol = 0#, atbol = 1#,
658 context = [], glasgow_exts = glaexts,
659 loc = mkSrcLoc SLIT("<interactive>") 1 } of
661 PFailed err -> do { hPutStrLn stderr (showSDoc err);
662 freeStringBuffer buf;
665 POk _ rdr_name -> do { --should, but can't: freeStringBuffer buf;
666 return (Just rdr_name) }
670 %************************************************************************
672 \subsection{Initial persistent state}
674 %************************************************************************
677 initPersistentCompilerState :: IO PersistentCompilerState
678 initPersistentCompilerState
679 = do prs <- initPersistentRenamerState
681 PCS { pcs_PIT = emptyIfaceTable,
682 pcs_PTE = wiredInThingEnv,
683 pcs_insts = emptyInstEnv,
684 pcs_rules = emptyRuleBase,
689 initPersistentRenamerState :: IO PersistentRenamerState
690 = do us <- mkSplitUniqSupply 'r'
692 PRS { prsOrig = NameSupply { nsUniqs = us,
693 nsNames = initOrigNames,
695 prsDecls = (emptyNameEnv, 0),
696 prsInsts = (emptyBag, 0),
697 prsRules = (emptyBag, 0),
702 initOrigNames :: FiniteMap (ModuleName,OccName) Name
704 = grab knownKeyNames `plusFM` grab (map getName wiredInThings)
706 grab names = foldl add emptyFM names
708 = addToFM env (moduleName (nameModule name), nameOccName name) name