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 ( mkUnqual, mkQual )
22 import RdrHsSyn ( RdrNameStmt )
23 import OccName ( varName, dataName, tcClsName )
25 import Id ( Id, idName, setGlobalIdDetails )
26 import IdInfo ( GlobalIdDetails(VanillaGlobal) )
27 import HscTypes ( InteractiveContext(..) )
28 import PrelNames ( iNTERACTIVE )
29 import StringBuffer ( stringToStringBuffer )
30 import FastString ( mkFastString )
31 import Char ( isLower )
32 import DriverUtil ( split_longest_prefix )
38 import IdInfo ( CafInfo(..), CgInfoEnv, CgInfo(..) )
39 import StringBuffer ( hGetStringBuffer, freeStringBuffer )
41 import Lex ( PState(..), ParseResult(..) )
42 import SrcLoc ( mkSrcLoc )
43 import Finder ( findModule )
44 import Rename ( checkOldIface, renameModule, closeIfaceDecls )
45 import Rules ( emptyRuleBase )
46 import PrelInfo ( wiredInThingEnv, wiredInThings )
47 import PrelNames ( knownKeyNames )
48 import MkIface ( mkFinalIface )
50 import InstEnv ( emptyInstEnv )
53 import CoreUtils ( coreBindsSize )
54 import CoreTidy ( tidyCorePgm )
55 import CorePrep ( corePrepPgm )
57 import CoreToStg ( coreToStg )
58 import SimplStg ( stg2stg )
59 import CodeGen ( codeGen )
60 import CodeOutput ( codeOutput )
62 import Module ( ModuleName, moduleName, mkHomeModule,
65 import ErrUtils ( dumpIfSet_dyn, showPass, printError )
66 import Util ( unJust )
67 import UniqSupply ( mkSplitUniqSupply )
69 import Bag ( emptyBag )
72 import HscStats ( ppSourceStats )
74 import FiniteMap ( FiniteMap, plusFM, emptyFM, addToFM )
75 import OccName ( OccName )
76 import Name ( Name, nameModule, nameOccName, getName, isGlobalName )
77 import NameEnv ( emptyNameEnv, mkNameEnv )
78 import Module ( Module )
80 import IOExts ( newIORef, readIORef, writeIORef, unsafePerformIO )
83 import Maybe ( isJust, fromJust, catMaybes )
86 import MkExternalCore ( emitExternalCore )
90 %************************************************************************
92 \subsection{The main compiler pipeline}
94 %************************************************************************
99 = HscFail PersistentCompilerState -- updated PCS
100 -- concluded that it wasn't necessary
101 | HscNoRecomp PersistentCompilerState -- updated PCS
102 ModDetails -- new details (HomeSymbolTable additions)
103 ModIface -- new iface (if any compilation was done)
105 | HscRecomp PersistentCompilerState -- updated PCS
106 ModDetails -- new details (HomeSymbolTable additions)
107 ModIface -- new iface (if any compilation was done)
108 Bool -- stub_h exists
109 Bool -- stub_c exists
111 (Maybe ([UnlinkedBCO],ItblEnv)) -- interpreted code, if any
113 (Maybe ()) -- no interpreted code whatsoever
116 -- no errors or warnings; the individual passes
117 -- (parse/rename/typecheck) print messages themselves
123 -> ModuleLocation -- location info
124 -> Bool -- True <=> source unchanged
125 -> Bool -- True <=> have an object file (for msgs only)
126 -> Maybe ModIface -- old interface, if available
127 -> HomeSymbolTable -- for home module ModDetails
129 -> PersistentCompilerState -- IN: persistent compiler state
132 hscMain ghci_mode dflags mod location source_unchanged have_object
133 maybe_old_iface hst hit pcs
135 showPass dflags ("Checking old interface for hs = "
136 ++ show (ml_hs_file location)
137 ++ ", hspp = " ++ show (ml_hspp_file location));
139 (pcs_ch, errs_found, (recomp_reqd, maybe_checked_iface))
140 <- _scc_ "checkOldIface"
141 checkOldIface ghci_mode dflags hit hst pcs (ml_hi_file location)
142 source_unchanged maybe_old_iface;
145 return (HscFail pcs_ch)
148 let no_old_iface = not (isJust maybe_checked_iface)
149 what_next | recomp_reqd || no_old_iface = hscRecomp
150 | otherwise = hscNoRecomp
152 what_next ghci_mode dflags have_object mod location
153 maybe_checked_iface hst hit pcs_ch
157 -- we definitely expect to have the old interface available
158 hscNoRecomp ghci_mode dflags have_object
159 mod location (Just old_iface) hst hit pcs_ch
160 | ghci_mode == OneShot
162 hPutStrLn stderr "compilation IS NOT required";
163 let { bomb = panic "hscNoRecomp:OneShot" };
164 return (HscNoRecomp pcs_ch bomb bomb)
168 when (verbosity dflags >= 1) $
169 hPutStrLn stderr ("Skipping " ++
170 compMsg have_object mod location);
173 (pcs_cl, closure_errs, cl_hs_decls)
174 <- closeIfaceDecls dflags hit hst pcs_ch old_iface ;
176 return (HscFail pcs_cl)
181 <- typecheckIface dflags pcs_cl hst old_iface cl_hs_decls;
183 case maybe_tc_result of {
184 Nothing -> return (HscFail pcs_cl);
185 Just (pcs_tc, new_details) ->
187 return (HscNoRecomp pcs_tc new_details old_iface)
190 compMsg use_object mod location =
191 mod_str ++ take (max 0 (16 - length mod_str)) (repeat ' ')
192 ++" ( " ++ unJust "hscRecomp" (ml_hs_file location) ++ ", "
194 then unJust "hscRecomp" (ml_obj_file location)
197 where mod_str = moduleUserString mod
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
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
362 ------------------ Code generation ------------------
363 abstractC <- _scc_ "CodeGen"
364 codeGen dflags this_mod imported_modules
365 cost_centre_info fe_binders
366 local_tycons stg_binds
368 ------------------ Code output -----------------------
369 (stub_h_exists, stub_c_exists)
370 <- codeOutput dflags this_mod local_tycons
372 c_code h_code abstractC
374 return (stub_h_exists, stub_c_exists, Nothing, final_iface)
376 ; let final_details = tidy_details {md_binds = []}
379 -- and the answer is ...
380 ; return (HscRecomp pcs_final
383 stub_h_exists stub_c_exists
387 myParseModule dflags src_filename
388 = do -------------------------- Parser ----------------
389 showPass dflags "Parser"
392 buf <- hGetStringBuffer True{-expand tabs-} src_filename
394 let glaexts | dopt Opt_GlasgowExts dflags = 1#
397 case parseModule buf PState{ bol = 0#, atbol = 1#,
398 context = [], glasgow_exts = glaexts,
399 loc = mkSrcLoc (_PK_ src_filename) 1 } of {
401 PFailed err -> do { hPutStrLn stderr (showSDoc err);
402 freeStringBuffer buf;
405 POk _ rdr_module@(HsModule mod_name _ _ _ _ _ _) -> do {
407 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_module) ;
409 dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics"
410 (ppSourceStats False rdr_module) ;
412 return (Just rdr_module)
413 -- ToDo: free the string buffer later.
417 myCoreToStg dflags this_mod tidy_binds
419 () <- coreBindsSize tidy_binds `seq` return ()
420 -- TEMP: the above call zaps some space usage allocated by the
421 -- simplifier, which for reasons I don't understand, persists
422 -- thoroughout code generation
424 stg_binds <- _scc_ "Core2Stg" coreToStg dflags tidy_binds
426 (stg_binds2, cost_centre_info)
427 <- _scc_ "Core2Stg" stg2stg dflags this_mod stg_binds
429 let env_rhs :: CgInfoEnv
430 env_rhs = mkNameEnv [ (idName bndr, CgInfo (stgRhsArity rhs) caf_info)
431 | (bind,_) <- stg_binds2,
433 | stgBindHasCafRefs bind = MayHaveCafRefs
434 | otherwise = NoCafRefs,
435 (bndr,rhs) <- stgBindPairs bind ]
437 return (stg_binds2, cost_centre_info, env_rhs)
439 stgBindPairs (StgNonRec _ b r) = [(b,r)]
440 stgBindPairs (StgRec _ prs) = prs
446 %************************************************************************
448 \subsection{Compiling a do-statement}
450 %************************************************************************
458 -> PersistentCompilerState -- IN: persistent compiler state
459 -> InteractiveContext -- Context for compiling
460 -> String -- The statement
461 -> Bool -- just treat it as an expression
462 -> IO ( PersistentCompilerState,
468 When the UnlinkedBCOExpr is linked you get an HValue of type
470 When you run it you get a list of HValues that should be
471 the same length as the list of names; add them to the ClosureEnv.
473 A naked expression returns a singleton Name [it].
475 What you type The IO [HValue] that hscStmt returns
476 ------------- ------------------------------------
477 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
480 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
483 expr (of IO type) ==> expr >>= \ v -> return [v]
484 [NB: result not printed] bindings: [it]
487 expr (of non-IO type,
488 result showable) ==> let v = expr in print v >> return [v]
491 expr (of non-IO type,
492 result not showable) ==> error
495 hscStmt dflags hst hit pcs0 icontext stmt just_expr
499 ic_type_env = type_env,
500 ic_module = scope_mod } = icontext
502 do { maybe_stmt <- hscParseStmt dflags stmt
504 Nothing -> return (pcs0, Nothing)
505 Just parsed_stmt -> do {
507 let { notExprStmt (ExprStmt _ _ _) = False;
511 if (just_expr && notExprStmt parsed_stmt)
512 then do hPutStrLn stderr ("not an expression: `" ++ stmt ++ "'")
513 return (pcs0, Nothing)
517 (pcs1, print_unqual, maybe_renamed_stmt)
518 <- renameStmt dflags hit hst pcs0 scope_mod
519 iNTERACTIVE rn_env parsed_stmt
521 ; case maybe_renamed_stmt of
522 Nothing -> return (pcs0, Nothing)
523 Just (bound_names, rn_stmt) -> do {
528 then case rn_stmt of { (ExprStmt e _ _, decls) ->
529 typecheckExpr dflags pcs1 hst type_env
530 print_unqual iNTERACTIVE (e,decls) }
531 else typecheckStmt dflags pcs1 hst type_env
532 print_unqual iNTERACTIVE bound_names rn_stmt
534 ; case maybe_tc_return of
535 Nothing -> return (pcs0, Nothing)
536 Just (pcs2, tc_expr, bound_ids, ty) -> do {
539 ds_expr <- deSugarExpr dflags pcs2 hst iNTERACTIVE print_unqual tc_expr
542 ; simpl_expr <- simplifyExpr dflags pcs2 hst ds_expr
544 -- Tidy it (temporary, until coreSat does cloning)
545 ; tidy_expr <- tidyCoreExpr simpl_expr
547 -- Prepare for codegen
548 ; prepd_expr <- corePrepExpr dflags tidy_expr
551 ; bcos <- coreExprToBCOs dflags prepd_expr
554 -- Make all the bound ids "global" ids, now that
555 -- they're notionally top-level bindings. This is
556 -- important: otherwise when we come to compile an expression
557 -- using these ids later, the byte code generator will consider
558 -- the occurrences to be free rather than global.
559 global_bound_ids = map globaliseId bound_ids;
560 globaliseId id = setGlobalIdDetails id VanillaGlobal
562 ; return (pcs2, Just (global_bound_ids, ty, bcos))
566 hscParseStmt :: DynFlags -> String -> IO (Maybe RdrNameStmt)
567 hscParseStmt dflags str
568 = do -------------------------- Parser ----------------
569 showPass dflags "Parser"
572 buf <- stringToStringBuffer str
574 let glaexts | dopt Opt_GlasgowExts dflags = 1#
577 case parseStmt buf PState{ bol = 0#, atbol = 1#,
578 context = [], glasgow_exts = glaexts,
579 loc = mkSrcLoc SLIT("<no file>") 0 } of {
581 PFailed err -> do { hPutStrLn stderr (showSDoc err);
582 -- Not yet implemented in <4.11 freeStringBuffer buf;
585 -- no stmt: the line consisted of just space or comments
586 POk _ Nothing -> return Nothing;
588 POk _ (Just rdr_stmt) -> do {
590 --ToDo: can't free the string buffer until we've finished this
591 -- compilation sweep and all the identifiers have gone away.
592 --freeStringBuffer buf;
593 dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" (ppr rdr_stmt);
594 return (Just rdr_stmt)
599 %************************************************************************
601 \subsection{Getting information about an identifer}
603 %************************************************************************
607 hscThing -- like hscStmt, but deals with a single identifier
611 -> PersistentCompilerState -- IN: persistent compiler state
612 -> InteractiveContext -- Context for compiling
613 -> String -- The identifier
614 -> IO ( PersistentCompilerState,
617 hscThing dflags hst hit pcs0 icontext str
621 ic_type_env = type_env,
622 ic_module = scope_mod } = icontext
626 = [ mkQual ns (fmod,fvar) | ns <- namespaces var ]
628 = [ mkUnqual ns fstr | ns <- namespaces str ]
629 where (mod,var) = split_longest_prefix str '.'
630 fmod = mkFastString mod
631 fvar = mkFastString var
632 fstr = mkFastString str
633 namespaces s | isLower (head s) = [ varName ]
634 | otherwise = [ tcClsName, dataName ]
636 (pcs, unqual, maybe_rn_result) <-
637 renameRdrName dflags hit hst pcs0 scope_mod scope_mod
640 case maybe_rn_result of {
641 Nothing -> return (pcs, []);
642 Just (names, decls) -> do {
644 maybe_pcs <- typecheckExtraDecls dflags pcs hst unqual
648 Nothing -> return (pcs, []);
650 let maybe_ty_things = map (lookupType hst (pcs_PTE pcs)) names
652 return (pcs, catMaybes maybe_ty_things) }
657 %************************************************************************
659 \subsection{Initial persistent state}
661 %************************************************************************
664 initPersistentCompilerState :: IO PersistentCompilerState
665 initPersistentCompilerState
666 = do prs <- initPersistentRenamerState
668 PCS { pcs_PIT = emptyIfaceTable,
669 pcs_PTE = wiredInThingEnv,
670 pcs_insts = emptyInstEnv,
671 pcs_rules = emptyRuleBase,
676 initPersistentRenamerState :: IO PersistentRenamerState
677 = do us <- mkSplitUniqSupply 'r'
679 PRS { prsOrig = NameSupply { nsUniqs = us,
680 nsNames = initOrigNames,
682 prsDecls = (emptyNameEnv, 0),
683 prsInsts = (emptyBag, 0),
684 prsRules = (emptyBag, 0),
689 initOrigNames :: FiniteMap (ModuleName,OccName) Name
691 = grab knownKeyNames `plusFM` grab (map getName wiredInThings)
693 grab names = foldl add emptyFM names
695 = addToFM env (moduleName (nameModule name), nameOccName name) name