2 % (c) The University of Glasgow, 1996-2000
4 \section[CmdLineOpts]{Things to do with command-line options}
9 CoreToDo(..), buildCoreToDo, StgToDo(..),
11 SimplifierMode(..), FloatOutSwitches(..),
14 DynFlag(..), -- needed non-abstractly by DriverFlags
21 -- Manipulating DynFlags
22 defaultDynFlags, -- DynFlags
23 defaultHscLang, -- HscLang
24 dopt, -- DynFlag -> DynFlags -> Bool
25 dopt_set, dopt_unset, -- DynFlags -> DynFlag -> DynFlags
26 dopt_CoreToDo, -- DynFlags -> [CoreToDo]
27 dopt_StgToDo, -- DynFlags -> [StgToDo]
28 dopt_HscLang, -- DynFlags -> HscLang
29 dopt_OutName, -- DynFlags -> String
30 getOpts, -- (DynFlags -> [a]) -> IO [a]
35 -- Manipulating the DynFlags state
36 getDynFlags, -- IO DynFlags
37 setDynFlags, -- DynFlags -> IO ()
38 updDynFlags, -- (DynFlags -> DynFlags) -> IO ()
39 dynFlag, -- (DynFlags -> a) -> IO a
40 setDynFlag, unSetDynFlag, -- DynFlag -> IO ()
41 saveDynFlags, -- IO ()
42 restoreDynFlags, -- IO DynFlags
44 -- sets of warning opts
49 -- Output style options
51 opt_PprStyle_RawTypes,
56 opt_AutoSccsOnAllToplevs,
57 opt_AutoSccsOnExportedToplevs,
58 opt_AutoSccsOnIndividualCafs,
66 opt_MaxContextReductionDepth,
67 opt_IrrefutableTuples,
77 opt_LiberateCaseThreshold,
80 opt_SimplNoPreInlining,
81 opt_SimplExcessPrecision,
85 opt_UF_CreationThreshold,
87 opt_UF_FunAppDiscount,
96 opt_EnsureSplittableC,
108 #include "HsVersions.h"
110 import Constants -- Default values for some flags
112 import FastString ( FastString, mkFastString )
114 import Maybes ( firstJust )
117 import DATA_IOREF ( IORef, readIORef, writeIORef )
118 import UNSAFE_IO ( unsafePerformIO )
121 %************************************************************************
123 \subsection{Command-line options}
125 %************************************************************************
127 The hsc command-line options are split into two categories:
132 Static flags are represented by top-level values of type Bool or Int,
133 for example. They therefore have the same value throughout the
136 Dynamic flags are represented by an abstract type, DynFlags, which is
137 passed into hsc by the compilation manager for every compilation.
138 Dynamic flags are those that change on a per-compilation basis,
139 perhaps because they may be present in the OPTIONS pragma at the top
142 Other flag-related blurb:
144 A list of {\em ToDo}s is things to be done in a particular part of
145 processing. A (fictitious) example for the Core-to-Core simplifier
146 might be: run the simplifier, then run the strictness analyser, then
147 run the simplifier again (three ``todos'').
149 There are three ``to-do processing centers'' at the moment. In the
150 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
151 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
152 (\tr{simplStg/SimplStg.lhs}).
154 %************************************************************************
156 \subsection{Datatypes associated with command-line options}
158 %************************************************************************
161 data CoreToDo -- These are diff core-to-core passes,
162 -- which may be invoked in any order,
163 -- as many times as you like.
165 = CoreDoSimplify -- The core-to-core simplifier.
168 -- Each run of the simplifier can take a different
169 -- set of simplifier-specific flags.
171 | CoreDoFloatOutwards FloatOutSwitches
176 | CoreDoWorkerWrapper
179 | CoreDoOldStrictness
182 | CoreDoRuleCheck Int{-CompilerPhase-} String -- Check for non-application of rules
183 -- matching this string
185 | CoreDoNothing -- useful when building up lists of these things
190 = StgDoMassageForProfiling -- should be (next to) last
191 -- There's also setStgVarInfo, but its absolute "lastness"
192 -- is so critical that it is hardwired in (no flag).
197 data SimplifierMode -- See comments in SimplMonad
201 data SimplifierSwitch
202 = MaxSimplifierIterations Int
205 data FloatOutSwitches
206 = FloatOutSw Bool -- True <=> float lambdas to top level
207 Bool -- True <=> float constants to top level,
208 -- even if they do not escape a lambda
211 %************************************************************************
213 \subsection{Dynamic command-line options}
215 %************************************************************************
228 | Opt_D_dump_inlinings
229 | Opt_D_dump_occur_anal
234 | Opt_D_dump_simpl_iterations
243 | Opt_D_dump_worker_wrapper
244 | Opt_D_dump_rn_trace
245 | Opt_D_dump_rn_stats
247 | Opt_D_dump_simpl_stats
248 | Opt_D_dump_tc_trace
253 | Opt_D_verbose_core2core
254 | Opt_D_verbose_stg2stg
256 | Opt_D_dump_hi_diffs
257 | Opt_D_dump_minimal_imports
261 | Opt_WarnIsError -- -Werror; makes warnings fatal
262 | Opt_WarnDuplicateExports
264 | Opt_WarnIncompletePatterns
265 | Opt_WarnMissingFields
266 | Opt_WarnMissingMethods
267 | Opt_WarnMissingSigs
268 | Opt_WarnNameShadowing
269 | Opt_WarnOverlappingPatterns
270 | Opt_WarnSimplePatterns
271 | Opt_WarnTypeDefaults
272 | Opt_WarnUnusedBinds
273 | Opt_WarnUnusedImports
274 | Opt_WarnUnusedMatches
275 | Opt_WarnDeprecations
279 | Opt_AllowOverlappingInstances
280 | Opt_AllowUndecidableInstances
281 | Opt_AllowIncoherentInstances
282 | Opt_NoMonomorphismRestriction
285 | Opt_PArr -- syntactic support for parallel arrays
286 | Opt_With -- deprecated keyword for implicit parms
287 | Opt_Arrows -- Arrow-notation syntax
291 | Opt_NoImplicitPrelude
296 | Opt_IgnoreInterfacePragmas
297 | Opt_OmitInterfacePragmas
298 | Opt_DoLambdaEtaExpansion
302 | Opt_UnboxStrictFields
306 data DynFlags = DynFlags {
307 coreToDo :: Maybe [CoreToDo], -- reserved for use with -Ofile
308 stgToDo :: [StgToDo],
310 hscOutName :: String, -- name of the output file
311 hscStubHOutName :: String, -- name of the .stub_h output file
312 hscStubCOutName :: String, -- name of the .stub_c output file
313 extCoreName :: String, -- name of the .core output file
314 verbosity :: Int, -- verbosity level
315 optLevel :: Int, -- optimisation level
316 maxSimplIterations :: Int, -- max simplifier iterations
317 ruleCheck :: Maybe String,
318 cppFlag :: Bool, -- preprocess with cpp?
319 ppFlag :: Bool, -- preprocess with a Haskell Pp?
320 stolen_x86_regs :: Int,
321 cmdlineHcIncludes :: [String], -- -#includes
323 -- options for particular phases
349 | cGhcWithNativeCodeGen == "YES" &&
350 (prefixMatch "i386" cTARGETPLATFORM ||
351 prefixMatch "sparc" cTARGETPLATFORM ||
352 prefixMatch "powerpc" cTARGETPLATFORM) = HscAsm
355 defaultDynFlags = DynFlags {
356 coreToDo = Nothing, stgToDo = [],
357 hscLang = defaultHscLang,
359 hscStubHOutName = "", hscStubCOutName = "",
363 maxSimplIterations = 4,
368 cmdlineHcIncludes = [],
381 -- Generating the helper-functions for
382 -- generics is now on by default
384 -- strictness is on by default, but this only
387 -- similarly for CSE.
388 Opt_DoLambdaEtaExpansion
389 -- This one is important for a tiresome reason:
390 -- we want to make sure that the bindings for data
391 -- constructors are eta-expanded. This is probably
392 -- a good thing anyway, but it seems fragile.
393 ] ++ standardWarnings,
399 0 | print errors & warnings only
400 1 | minimal verbosity: print "compiling M ... done." for each module.
401 2 | equivalent to -dshow-passes
402 3 | equivalent to existing "ghc -v"
403 4 | "ghc -v -ddump-most"
404 5 | "ghc -v -ddump-all"
407 dopt :: DynFlag -> DynFlags -> Bool
408 dopt f dflags = f `elem` (flags dflags)
410 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
411 dopt_CoreToDo = coreToDo
413 dopt_StgToDo :: DynFlags -> [StgToDo]
414 dopt_StgToDo = stgToDo
416 dopt_OutName :: DynFlags -> String
417 dopt_OutName = hscOutName
419 dopt_HscLang :: DynFlags -> HscLang
420 dopt_HscLang = hscLang
422 dopt_set :: DynFlags -> DynFlag -> DynFlags
423 dopt_set dfs f = dfs{ flags = f : flags dfs }
425 dopt_unset :: DynFlags -> DynFlag -> DynFlags
426 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
428 getOpts :: (DynFlags -> [a]) -> IO [a]
429 -- We add to the options from the front, so we need to reverse the list
430 getOpts opts = dynFlag opts >>= return . reverse
432 -- we can only switch between HscC, HscAsmm, and HscILX with dynamic flags
433 -- (-fvia-C, -fasm, -filx respectively).
434 setLang l = updDynFlags (\ dfs -> case hscLang dfs of
435 HscC -> dfs{ hscLang = l }
436 HscAsm -> dfs{ hscLang = l }
437 HscILX -> dfs{ hscLang = l }
441 verb <- dynFlag verbosity
442 if verb >= 3 then return "-v" else return ""
444 -----------------------------------------------------------------------------
445 -- Setting the optimisation level
447 setOptLevel :: Int -> IO ()
449 = do dflags <- getDynFlags
450 if hscLang dflags == HscInterpreted && n > 0
451 then putStr "warning: -O conflicts with --interactive; -O ignored.\n"
452 else updDynFlags (setOptLevel' n)
456 then dfs2{ hscLang = HscC, optLevel = n } -- turn on -fvia-C with -O
457 else dfs2{ optLevel = n }
459 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
460 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
463 | n == 0 = opt_0_dopts
464 | otherwise = opt_1_dopts
467 | n == 0 = opt_1_dopts
468 | otherwise = opt_0_dopts
471 Opt_IgnoreInterfacePragmas,
472 Opt_OmitInterfacePragmas
481 -- Core-to-core phases:
483 buildCoreToDo :: DynFlags -> [CoreToDo]
484 buildCoreToDo dflags = core_todo
486 opt_level = optLevel dflags
487 max_iter = maxSimplIterations dflags
488 strictness = dopt Opt_Strictness dflags
489 cse = dopt Opt_CSE dflags
490 rule_check = ruleCheck dflags
493 if opt_level == 0 then
495 CoreDoSimplify (SimplPhase 0) [
496 MaxSimplifierIterations max_iter
500 else {- opt_level >= 1 -} [
502 -- initial simplify: mk specialiser happy: minimum effort please
503 CoreDoSimplify SimplGently [
505 -- Don't inline anything till full laziness has bitten
506 -- In particular, inlining wrappers inhibits floating
507 -- e.g. ...(case f x of ...)...
508 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
509 -- ==> ...(case x of I# x# -> case fw x# of ...)...
510 -- and now the redex (f x) isn't floatable any more
511 -- Similarly, don't apply any rules until after full
512 -- laziness. Notably, list fusion can prevent floating.
515 -- Don't do case-of-case transformations.
516 -- This makes full laziness work better
517 MaxSimplifierIterations max_iter
520 -- Specialisation is best done before full laziness
521 -- so that overloaded functions have all their dictionary lambdas manifest
524 CoreDoFloatOutwards (FloatOutSw False False),
527 CoreDoSimplify (SimplPhase 2) [
528 -- Want to run with inline phase 2 after the specialiser to give
529 -- maximum chance for fusion to work before we inline build/augment
530 -- in phase 1. This made a difference in 'ansi' where an
531 -- overloaded function wasn't inlined till too late.
532 MaxSimplifierIterations max_iter
534 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
536 CoreDoSimplify (SimplPhase 1) [
537 -- Need inline-phase2 here so that build/augment get
538 -- inlined. I found that spectral/hartel/genfft lost some useful
539 -- strictness in the function sumcode' if augment is not inlined
540 -- before strictness analysis runs
541 MaxSimplifierIterations max_iter
543 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
545 CoreDoSimplify (SimplPhase 0) [
546 -- Phase 0: allow all Ids to be inlined now
547 -- This gets foldr inlined before strictness analysis
549 MaxSimplifierIterations 3
550 -- At least 3 iterations because otherwise we land up with
551 -- huge dead expressions because of an infelicity in the
553 -- let k = BIG in foldr k z xs
554 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
555 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
559 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
561 #ifdef OLD_STRICTNESS
564 if strictness then CoreDoStrictness else CoreDoNothing,
568 CoreDoSimplify (SimplPhase 0) [
569 MaxSimplifierIterations max_iter
572 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
573 True), -- Float constants
574 -- nofib/spectral/hartel/wang doubles in speed if you
575 -- do full laziness late in the day. It only happens
576 -- after fusion and other stuff, so the early pass doesn't
577 -- catch it. For the record, the redex is
578 -- f_el22 (f_el21 r_midblock)
581 -- We want CSE to follow the final full-laziness pass, because it may
582 -- succeed in commoning up things floated out by full laziness.
583 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
585 if cse then CoreCSE else CoreDoNothing,
589 -- Case-liberation for -O2. This should be after
590 -- strictness analysis and the simplification which follows it.
592 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
594 if opt_level >= 2 then
598 if opt_level >= 2 then
603 -- Final clean-up simplification:
604 CoreDoSimplify (SimplPhase 0) [
605 MaxSimplifierIterations max_iter
609 -- --------------------------------------------------------------------------
610 -- Mess about with the mutable variables holding the dynamic arguments
613 -- is the "baseline" dynamic flags, initialised from
614 -- the defaults and command line options, and updated by the
615 -- ':s' command in GHCi.
618 -- is the dynamic flags for the current compilation. It is reset
619 -- to the value of v_InitDynFlags before each compilation, then
620 -- updated by reading any OPTIONS pragma in the current module.
622 GLOBAL_VAR(v_InitDynFlags, defaultDynFlags, DynFlags)
623 GLOBAL_VAR(v_DynFlags, defaultDynFlags, DynFlags)
625 setDynFlags :: DynFlags -> IO ()
626 setDynFlags dfs = writeIORef v_DynFlags dfs
628 saveDynFlags :: IO ()
629 saveDynFlags = do dfs <- readIORef v_DynFlags
630 writeIORef v_InitDynFlags dfs
632 restoreDynFlags :: IO DynFlags
633 restoreDynFlags = do dfs <- readIORef v_InitDynFlags
634 writeIORef v_DynFlags dfs
637 getDynFlags :: IO DynFlags
638 getDynFlags = readIORef v_DynFlags
640 updDynFlags :: (DynFlags -> DynFlags) -> IO ()
641 updDynFlags f = do dfs <- readIORef v_DynFlags
642 writeIORef v_DynFlags (f dfs)
644 dynFlag :: (DynFlags -> a) -> IO a
645 dynFlag f = do dflags <- readIORef v_DynFlags; return (f dflags)
647 setDynFlag, unSetDynFlag :: DynFlag -> IO ()
648 setDynFlag f = updDynFlags (\dfs -> dopt_set dfs f)
649 unSetDynFlag f = updDynFlags (\dfs -> dopt_unset dfs f)
653 %************************************************************************
655 \subsection{Warnings}
657 %************************************************************************
661 = [ Opt_WarnDeprecations,
662 Opt_WarnOverlappingPatterns,
663 Opt_WarnMissingFields,
664 Opt_WarnMissingMethods,
665 Opt_WarnDuplicateExports
669 = standardWarnings ++
670 [ Opt_WarnUnusedBinds,
671 Opt_WarnUnusedMatches,
672 Opt_WarnUnusedImports,
673 Opt_WarnIncompletePatterns,
679 [ Opt_WarnTypeDefaults,
680 Opt_WarnNameShadowing,
686 %************************************************************************
688 \subsection{Classifying command-line options}
690 %************************************************************************
693 -- v_Statis_hsc_opts is here to avoid a circular dependency with
695 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
697 lookUp :: FastString -> Bool
698 lookup_int :: String -> Maybe Int
699 lookup_def_int :: String -> Int -> Int
700 lookup_def_float :: String -> Float -> Float
701 lookup_str :: String -> Maybe String
703 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
704 packed_static_opts = map mkFastString unpacked_static_opts
706 lookUp sw = sw `elem` packed_static_opts
708 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
710 lookup_int sw = case (lookup_str sw) of
712 Just xx -> Just (read xx)
714 lookup_def_int sw def = case (lookup_str sw) of
715 Nothing -> def -- Use default
718 lookup_def_float sw def = case (lookup_str sw) of
719 Nothing -> def -- Use default
724 Putting the compiler options into temporary at-files
725 may turn out to be necessary later on if we turn hsc into
726 a pure Win32 application where I think there's a command-line
727 length limit of 255. unpacked_opts understands the @ option.
729 unpacked_opts :: [String]
733 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
735 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
740 %************************************************************************
742 \subsection{Static options}
744 %************************************************************************
748 opt_PprStyle_NoPrags = lookUp FSLIT("-dppr-noprags")
749 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
750 opt_PprStyle_RawTypes = lookUp FSLIT("-dppr-rawtypes")
751 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
754 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
755 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
756 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
757 opt_AutoSccsOnDicts = lookUp FSLIT("-fauto-sccs-on-dicts")
758 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
759 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
762 opt_AllStrict = lookUp FSLIT("-fall-strict")
763 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
764 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
765 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
766 opt_NumbersStrict = lookUp FSLIT("-fnumbers-strict")
767 opt_Parallel = lookUp FSLIT("-fparallel")
768 opt_SMP = lookUp FSLIT("-fsmp")
769 opt_Flatten = lookUp FSLIT("-fflatten")
772 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
773 opt_DoSemiTagging = lookUp FSLIT("-fsemi-tagging")
774 opt_CprOff = lookUp FSLIT("-fcpr-off")
775 opt_RulesOff = lookUp FSLIT("-frules-off")
776 -- Switch off CPR analysis in the new demand analyser
777 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
778 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
781 The optional '-inpackage=P' flag tells what package
782 we are compiling this module for.
783 The Prelude, for example is compiled with '-inpackage std'
785 opt_InPackage = case lookup_str "-inpackage=" of
786 Just p -> mkFastString p
787 Nothing -> FSLIT("Main") -- The package name if none is specified
789 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
790 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
791 opt_GranMacros = lookUp FSLIT("-fgransim")
792 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
793 opt_HistorySize = lookup_def_int "-fhistory-size" 20
794 opt_NoHiCheck = lookUp FSLIT("-fno-hi-version-check")
795 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
796 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
798 -- Simplifier switches
799 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
800 -- NoPreInlining is there just to see how bad things
801 -- get if you don't do it!
802 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
805 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
806 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
807 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
808 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
809 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
811 opt_UF_CheapOp = ( 1 :: Int) -- Only one instruction; and the args are charged for
812 opt_UF_DearOp = ( 4 :: Int)
814 opt_NoPruneDecls = lookUp FSLIT("-fno-prune-decls")
815 opt_Static = lookUp FSLIT("-static")
816 opt_Unregisterised = lookUp FSLIT("-funregisterised")
817 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
820 %************************************************************************
822 \subsection{List of static hsc flags}
824 %************************************************************************
829 "fauto-sccs-on-all-toplevs",
830 "fauto-sccs-on-exported-toplevs",
831 "fauto-sccs-on-individual-cafs",
832 "fauto-sccs-on-dicts",
837 "firrefutable-tuples",
844 "femit-extern-decls",
845 "fglobalise-toplev-names",
847 "fno-hi-version-check",
849 "fno-method-sharing",
853 "funfolding-update-in-place",
862 || any (flip prefixMatch f) [
864 "fliberate-case-threshold",
867 "funfolding-creation-threshold",
868 "funfolding-use-threshold",
869 "funfolding-fun-discount",
870 "funfolding-keeness-factor"
874 %************************************************************************
876 \subsection{Misc functions for command-line options}
878 %************************************************************************
883 startsWith :: String -> String -> Maybe String
884 -- startsWith pfx (pfx++rest) = Just rest
886 startsWith [] str = Just str
887 startsWith (c:cs) (s:ss)
888 = if c /= s then Nothing else startsWith cs ss
889 startsWith _ [] = Nothing
891 endsWith :: String -> String -> Maybe String
893 = case (startsWith (reverse cs) (reverse ss)) of
895 Just rs -> Just (reverse rs)