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
22 -- Manipulating DynFlags
23 defaultDynFlags, -- DynFlags
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_HscTarget, -- DynFlags -> HscTarget
29 dopt_OutName, -- DynFlags -> String
30 getOpts, -- (DynFlags -> [a]) -> IO [a]
34 -- sets of warning opts
38 -- Output style options
43 opt_AutoSccsOnAllToplevs,
44 opt_AutoSccsOnExportedToplevs,
45 opt_AutoSccsOnIndividualCafs,
51 opt_MaxContextReductionDepth,
52 opt_IrrefutableTuples,
61 opt_LiberateCaseThreshold,
64 opt_SimplNoPreInlining,
65 opt_SimplExcessPrecision,
69 opt_UF_CreationThreshold,
71 opt_UF_FunAppDiscount,
79 opt_EnsureSplittableC,
90 #include "HsVersions.h"
92 import {-# SOURCE #-} Packages (PackageState)
93 import DriverPhases ( HscTarget(..) )
94 import Constants -- Default values for some flags
96 import FastString ( FastString, mkFastString )
98 import Maybes ( firstJust )
100 import Panic ( ghcError, GhcException(UsageError) )
102 import DATA_IOREF ( IORef, readIORef )
103 import UNSAFE_IO ( unsafePerformIO )
106 %************************************************************************
108 \subsection{Command-line options}
110 %************************************************************************
112 The hsc command-line options are split into two categories:
117 Static flags are represented by top-level values of type Bool or Int,
118 for example. They therefore have the same value throughout the
121 Dynamic flags are represented by an abstract type, DynFlags, which is
122 passed into hsc by the compilation manager for every compilation.
123 Dynamic flags are those that change on a per-compilation basis,
124 perhaps because they may be present in the OPTIONS pragma at the top
127 Other flag-related blurb:
129 A list of {\em ToDo}s is things to be done in a particular part of
130 processing. A (fictitious) example for the Core-to-Core simplifier
131 might be: run the simplifier, then run the strictness analyser, then
132 run the simplifier again (three ``todos'').
134 There are three ``to-do processing centers'' at the moment. In the
135 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
136 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
137 (\tr{simplStg/SimplStg.lhs}).
139 %************************************************************************
141 \subsection{Datatypes associated with command-line options}
143 %************************************************************************
146 data CoreToDo -- These are diff core-to-core passes,
147 -- which may be invoked in any order,
148 -- as many times as you like.
150 = CoreDoSimplify -- The core-to-core simplifier.
153 -- Each run of the simplifier can take a different
154 -- set of simplifier-specific flags.
156 | CoreDoFloatOutwards FloatOutSwitches
161 | CoreDoWorkerWrapper
164 | CoreDoOldStrictness
167 | CoreDoRuleCheck Int{-CompilerPhase-} String -- Check for non-application of rules
168 -- matching this string
170 | CoreDoNothing -- useful when building up lists of these things
175 = StgDoMassageForProfiling -- should be (next to) last
176 -- There's also setStgVarInfo, but its absolute "lastness"
177 -- is so critical that it is hardwired in (no flag).
182 data SimplifierMode -- See comments in SimplMonad
186 data SimplifierSwitch
187 = MaxSimplifierIterations Int
190 data FloatOutSwitches
191 = FloatOutSw Bool -- True <=> float lambdas to top level
192 Bool -- True <=> float constants to top level,
193 -- even if they do not escape a lambda
196 %************************************************************************
198 \subsection{Dynamic command-line options}
200 %************************************************************************
213 | Opt_D_dump_inlinings
214 | Opt_D_dump_occur_anal
218 | Opt_D_dump_simpl_iterations
227 | Opt_D_dump_worker_wrapper
228 | Opt_D_dump_rn_trace
229 | Opt_D_dump_rn_stats
231 | Opt_D_dump_simpl_stats
232 | Opt_D_dump_tc_trace
233 | Opt_D_dump_if_trace
238 | Opt_D_verbose_core2core
239 | Opt_D_verbose_stg2stg
241 | Opt_D_dump_hi_diffs
242 | Opt_D_dump_minimal_imports
247 | Opt_WarnIsError -- -Werror; makes warnings fatal
248 | Opt_WarnDuplicateExports
250 | Opt_WarnIncompletePatterns
251 | Opt_WarnIncompletePatternsRecUpd
252 | Opt_WarnMissingFields
253 | Opt_WarnMissingMethods
254 | Opt_WarnMissingSigs
255 | Opt_WarnNameShadowing
256 | Opt_WarnOverlappingPatterns
257 | Opt_WarnSimplePatterns
258 | Opt_WarnTypeDefaults
259 | Opt_WarnUnusedBinds
260 | Opt_WarnUnusedImports
261 | Opt_WarnUnusedMatches
262 | Opt_WarnDeprecations
263 | Opt_WarnDodgyImports
267 | Opt_AllowOverlappingInstances
268 | Opt_AllowUndecidableInstances
269 | Opt_AllowIncoherentInstances
270 | Opt_MonomorphismRestriction
273 | Opt_PArr -- syntactic support for parallel arrays
274 | Opt_Arrows -- Arrow-notation syntax
278 | Opt_ImplicitPrelude
279 | Opt_ScopedTypeVariables
285 | Opt_IgnoreInterfacePragmas
286 | Opt_OmitInterfacePragmas
287 | Opt_DoLambdaEtaExpansion
291 | Opt_UnboxStrictFields
295 data DynFlags = DynFlags {
296 coreToDo :: Maybe [CoreToDo], -- reserved for use with -Ofile
297 stgToDo :: [StgToDo],
298 hscTarget :: HscTarget,
299 hscOutName :: String, -- name of the output file
300 hscStubHOutName :: String, -- name of the .stub_h output file
301 hscStubCOutName :: String, -- name of the .stub_c output file
302 extCoreName :: String, -- name of the .core output file
303 verbosity :: Int, -- verbosity level
304 optLevel :: Int, -- optimisation level
305 maxSimplIterations :: Int, -- max simplifier iterations
306 ruleCheck :: Maybe String,
307 cppFlag :: Bool, -- preprocess with cpp?
308 ppFlag :: Bool, -- preprocess with a Haskell Pp?
309 recompFlag :: Bool, -- True <=> recompilation checker is on
310 stolen_x86_regs :: Int,
311 cmdlineHcIncludes :: [String], -- -#includes
312 importPaths :: [FilePath],
314 -- options for particular phases
327 extraPkgConfs :: [FilePath],
328 -- The -package-conf flags given on the command line, in the order
331 readUserPkgConf :: Bool,
332 -- Whether or not to read the user package database
333 -- (-no-user-package-conf).
335 packageFlags :: [PackageFlag],
336 -- The -package and -hide-package flags from the command-line
339 pkgState :: PackageState,
346 = ExposePackage String
348 | IgnorePackage String
351 #if defined(i386_TARGET_ARCH) || defined(sparc_TARGET_ARCH) || defined(powerpc_TARGET_ARCH)
352 | cGhcWithNativeCodeGen == "YES" = HscAsm
356 defaultDynFlags = DynFlags {
357 coreToDo = Nothing, stgToDo = [],
358 hscTarget = defaultHscTarget,
360 hscStubHOutName = "", hscStubCOutName = "",
364 maxSimplIterations = 4,
370 cmdlineHcIncludes = [],
384 readUserPkgConf = True,
386 pkgState = error "pkgState",
390 Opt_MonomorphismRestriction,
392 -- Generating the helper-functions for
393 -- generics is now on by default
395 -- strictness is on by default, but this only
397 Opt_CSE, -- similarly for CSE.
398 Opt_FullLaziness, -- ...and for full laziness
400 Opt_DoLambdaEtaExpansion,
401 -- This one is important for a tiresome reason:
402 -- we want to make sure that the bindings for data
403 -- constructors are eta-expanded. This is probably
404 -- a good thing anyway, but it seems fragile.
406 -- and the default no-optimisation options:
407 Opt_IgnoreInterfacePragmas,
408 Opt_OmitInterfacePragmas
410 ] ++ standardWarnings
416 0 | print errors & warnings only
417 1 | minimal verbosity: print "compiling M ... done." for each module.
418 2 | equivalent to -dshow-passes
419 3 | equivalent to existing "ghc -v"
420 4 | "ghc -v -ddump-most"
421 5 | "ghc -v -ddump-all"
424 dopt :: DynFlag -> DynFlags -> Bool
425 dopt f dflags = f `elem` (flags dflags)
427 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
428 dopt_CoreToDo = coreToDo
430 dopt_StgToDo :: DynFlags -> [StgToDo]
431 dopt_StgToDo = stgToDo
433 dopt_OutName :: DynFlags -> String
434 dopt_OutName = hscOutName
436 dopt_HscTarget :: DynFlags -> HscTarget
437 dopt_HscTarget = hscTarget
439 dopt_set :: DynFlags -> DynFlag -> DynFlags
440 dopt_set dfs f = dfs{ flags = f : flags dfs }
442 dopt_unset :: DynFlags -> DynFlag -> DynFlags
443 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
445 getOpts :: DynFlags -> (DynFlags -> [a]) -> [a]
446 -- We add to the options from the front, so we need to reverse the list
447 getOpts dflags opts = reverse (opts dflags)
450 | verbosity dflags >= 3 = "-v"
453 -----------------------------------------------------------------------------
454 -- Setting the optimisation level
458 then dfs2{ hscTarget = HscC, optLevel = n } -- turn on -fvia-C with -O
459 else dfs2{ optLevel = n }
461 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
462 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
465 | n == 0 = opt_0_dopts
466 | otherwise = opt_1_dopts
469 | n == 0 = opt_1_dopts
470 | otherwise = opt_0_dopts
473 Opt_IgnoreInterfacePragmas,
474 Opt_OmitInterfacePragmas
483 -- Core-to-core phases:
485 buildCoreToDo :: DynFlags -> [CoreToDo]
486 buildCoreToDo dflags = core_todo
488 opt_level = optLevel dflags
489 max_iter = maxSimplIterations dflags
490 strictness = dopt Opt_Strictness dflags
491 full_laziness = dopt Opt_FullLaziness dflags
492 cse = dopt Opt_CSE dflags
493 rule_check = ruleCheck dflags
496 if opt_level == 0 then
498 CoreDoSimplify (SimplPhase 0) [
499 MaxSimplifierIterations max_iter
503 else {- opt_level >= 1 -} [
505 -- initial simplify: mk specialiser happy: minimum effort please
506 CoreDoSimplify SimplGently [
508 -- Don't inline anything till full laziness has bitten
509 -- In particular, inlining wrappers inhibits floating
510 -- e.g. ...(case f x of ...)...
511 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
512 -- ==> ...(case x of I# x# -> case fw x# of ...)...
513 -- and now the redex (f x) isn't floatable any more
514 -- Similarly, don't apply any rules until after full
515 -- laziness. Notably, list fusion can prevent floating.
518 -- Don't do case-of-case transformations.
519 -- This makes full laziness work better
520 MaxSimplifierIterations max_iter
523 -- Specialisation is best done before full laziness
524 -- so that overloaded functions have all their dictionary lambdas manifest
527 if full_laziness then CoreDoFloatOutwards (FloatOutSw False False)
532 CoreDoSimplify (SimplPhase 2) [
533 -- Want to run with inline phase 2 after the specialiser to give
534 -- maximum chance for fusion to work before we inline build/augment
535 -- in phase 1. This made a difference in 'ansi' where an
536 -- overloaded function wasn't inlined till too late.
537 MaxSimplifierIterations max_iter
539 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
541 CoreDoSimplify (SimplPhase 1) [
542 -- Need inline-phase2 here so that build/augment get
543 -- inlined. I found that spectral/hartel/genfft lost some useful
544 -- strictness in the function sumcode' if augment is not inlined
545 -- before strictness analysis runs
546 MaxSimplifierIterations max_iter
548 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
550 CoreDoSimplify (SimplPhase 0) [
551 -- Phase 0: allow all Ids to be inlined now
552 -- This gets foldr inlined before strictness analysis
554 MaxSimplifierIterations 3
555 -- At least 3 iterations because otherwise we land up with
556 -- huge dead expressions because of an infelicity in the
558 -- let k = BIG in foldr k z xs
559 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
560 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
564 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
566 #ifdef OLD_STRICTNESS
569 if strictness then CoreDoStrictness else CoreDoNothing,
573 CoreDoSimplify (SimplPhase 0) [
574 MaxSimplifierIterations max_iter
577 if full_laziness then
578 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
579 True) -- Float constants
581 -- nofib/spectral/hartel/wang doubles in speed if you
582 -- do full laziness late in the day. It only happens
583 -- after fusion and other stuff, so the early pass doesn't
584 -- catch it. For the record, the redex is
585 -- f_el22 (f_el21 r_midblock)
588 -- We want CSE to follow the final full-laziness pass, because it may
589 -- succeed in commoning up things floated out by full laziness.
590 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
592 if cse then CoreCSE else CoreDoNothing,
596 -- Case-liberation for -O2. This should be after
597 -- strictness analysis and the simplification which follows it.
599 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
601 if opt_level >= 2 then
605 if opt_level >= 2 then
610 -- Final clean-up simplification:
611 CoreDoSimplify (SimplPhase 0) [
612 MaxSimplifierIterations max_iter
617 %************************************************************************
619 \subsection{Warnings}
621 %************************************************************************
625 = [ Opt_WarnDeprecations,
626 Opt_WarnOverlappingPatterns,
627 Opt_WarnMissingFields,
628 Opt_WarnMissingMethods,
629 Opt_WarnDuplicateExports
633 = standardWarnings ++
634 [ Opt_WarnUnusedBinds,
635 Opt_WarnUnusedMatches,
636 Opt_WarnUnusedImports,
637 Opt_WarnIncompletePatterns,
643 [ Opt_WarnTypeDefaults,
644 Opt_WarnNameShadowing,
651 %************************************************************************
653 \subsection{Classifying command-line options}
655 %************************************************************************
658 -- v_Statis_hsc_opts is here to avoid a circular dependency with
660 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
662 lookUp :: FastString -> Bool
663 lookup_def_int :: String -> Int -> Int
664 lookup_def_float :: String -> Float -> Float
665 lookup_str :: String -> Maybe String
667 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
668 packed_static_opts = map mkFastString unpacked_static_opts
670 lookUp sw = sw `elem` packed_static_opts
672 -- (lookup_str "foo") looks for the flag -foo=X or -fooX,
673 -- and returns the string X
675 = case firstJust (map (startsWith sw) unpacked_static_opts) of
676 Just ('=' : str) -> Just str
680 lookup_def_int sw def = case (lookup_str sw) of
681 Nothing -> def -- Use default
682 Just xx -> try_read sw xx
684 lookup_def_float sw def = case (lookup_str sw) of
685 Nothing -> def -- Use default
686 Just xx -> try_read sw xx
689 try_read :: Read a => String -> String -> a
690 -- (try_read sw str) tries to read s; if it fails, it
691 -- bleats about flag sw
694 ((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
695 [] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))
696 -- ToDo: hack alert. We should really parse the arugments
697 -- and announce errors in a more civilised way.
701 Putting the compiler options into temporary at-files
702 may turn out to be necessary later on if we turn hsc into
703 a pure Win32 application where I think there's a command-line
704 length limit of 255. unpacked_opts understands the @ option.
706 unpacked_opts :: [String]
710 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
712 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
717 %************************************************************************
719 \subsection{Static options}
721 %************************************************************************
725 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
726 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
729 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
730 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
731 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
732 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
733 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
736 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
737 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
738 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
739 opt_Parallel = lookUp FSLIT("-fparallel")
740 opt_SMP = lookUp FSLIT("-fsmp")
741 opt_Flatten = lookUp FSLIT("-fflatten")
744 opt_NoStateHack = lookUp FSLIT("-fno-state-hack")
745 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
746 opt_CprOff = lookUp FSLIT("-fcpr-off")
747 opt_RulesOff = lookUp FSLIT("-frules-off")
748 -- Switch off CPR analysis in the new demand analyser
749 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
750 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
752 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
753 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
754 opt_GranMacros = lookUp FSLIT("-fgransim")
755 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
756 opt_HistorySize = lookup_def_int "-fhistory-size" 20
757 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
758 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
760 -- Simplifier switches
761 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
762 -- NoPreInlining is there just to see how bad things
763 -- get if you don't do it!
764 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
767 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
768 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
769 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
770 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
771 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
773 opt_UF_DearOp = ( 4 :: Int)
775 opt_Static = lookUp FSLIT("-static")
776 opt_Unregisterised = lookUp FSLIT("-funregisterised")
777 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
779 -- Include full span info in error messages, instead of just the start position.
780 opt_ErrorSpans = lookUp FSLIT("-ferror-spans")
782 opt_PIC = lookUp FSLIT("-fPIC")
785 %************************************************************************
787 \subsection{List of static hsc flags}
789 %************************************************************************
794 "fauto-sccs-on-all-toplevs",
795 "fauto-sccs-on-exported-toplevs",
796 "fauto-sccs-on-individual-cafs",
797 "fauto-sccs-on-dicts",
802 "firrefutable-tuples",
808 "femit-extern-decls",
809 "fglobalise-toplev-names",
811 "fno-hi-version-check",
813 "fno-method-sharing",
818 "funfolding-update-in-place",
828 || any (flip prefixMatch f) [
830 "fliberate-case-threshold",
833 "funfolding-creation-threshold",
834 "funfolding-use-threshold",
835 "funfolding-fun-discount",
836 "funfolding-keeness-factor"
840 %************************************************************************
842 \subsection{Misc functions for command-line options}
844 %************************************************************************
849 startsWith :: String -> String -> Maybe String
850 -- startsWith pfx (pfx++rest) = Just rest
852 startsWith [] str = Just str
853 startsWith (c:cs) (s:ss)
854 = if c /= s then Nothing else startsWith cs ss
855 startsWith _ [] = Nothing