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 -- strictness is on by default, but this only
394 Opt_CSE, -- similarly for CSE.
395 Opt_FullLaziness, -- ...and for full laziness
397 Opt_DoLambdaEtaExpansion,
398 -- This one is important for a tiresome reason:
399 -- we want to make sure that the bindings for data
400 -- constructors are eta-expanded. This is probably
401 -- a good thing anyway, but it seems fragile.
403 -- and the default no-optimisation options:
404 Opt_IgnoreInterfacePragmas,
405 Opt_OmitInterfacePragmas
407 ] ++ standardWarnings
413 0 | print errors & warnings only
414 1 | minimal verbosity: print "compiling M ... done." for each module.
415 2 | equivalent to -dshow-passes
416 3 | equivalent to existing "ghc -v"
417 4 | "ghc -v -ddump-most"
418 5 | "ghc -v -ddump-all"
421 dopt :: DynFlag -> DynFlags -> Bool
422 dopt f dflags = f `elem` (flags dflags)
424 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
425 dopt_CoreToDo = coreToDo
427 dopt_StgToDo :: DynFlags -> [StgToDo]
428 dopt_StgToDo = stgToDo
430 dopt_OutName :: DynFlags -> String
431 dopt_OutName = hscOutName
433 dopt_HscTarget :: DynFlags -> HscTarget
434 dopt_HscTarget = hscTarget
436 dopt_set :: DynFlags -> DynFlag -> DynFlags
437 dopt_set dfs f = dfs{ flags = f : flags dfs }
439 dopt_unset :: DynFlags -> DynFlag -> DynFlags
440 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
442 getOpts :: DynFlags -> (DynFlags -> [a]) -> [a]
443 -- We add to the options from the front, so we need to reverse the list
444 getOpts dflags opts = reverse (opts dflags)
447 | verbosity dflags >= 3 = "-v"
450 -----------------------------------------------------------------------------
451 -- Setting the optimisation level
453 updOptLevel :: Int -> DynFlags -> DynFlags
454 -- Set dynflags appropriate to the optimisation level
457 then dfs2{ hscTarget = HscC, optLevel = n } -- turn on -fvia-C with -O
458 else dfs2{ optLevel = n }
460 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
461 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
464 | n == 0 = opt_0_dopts
465 | otherwise = opt_1_dopts
468 | n == 0 = opt_1_dopts
469 | otherwise = opt_0_dopts
472 Opt_IgnoreInterfacePragmas,
473 Opt_OmitInterfacePragmas
482 -- Core-to-core phases:
484 buildCoreToDo :: DynFlags -> [CoreToDo]
485 buildCoreToDo dflags = core_todo
487 opt_level = optLevel dflags
488 max_iter = maxSimplIterations dflags
489 strictness = dopt Opt_Strictness dflags
490 full_laziness = dopt Opt_FullLaziness dflags
491 cse = dopt Opt_CSE dflags
492 rule_check = ruleCheck dflags
495 if opt_level == 0 then
497 CoreDoSimplify (SimplPhase 0) [
498 MaxSimplifierIterations max_iter
502 else {- opt_level >= 1 -} [
504 -- initial simplify: mk specialiser happy: minimum effort please
505 CoreDoSimplify SimplGently [
507 -- Don't inline anything till full laziness has bitten
508 -- In particular, inlining wrappers inhibits floating
509 -- e.g. ...(case f x of ...)...
510 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
511 -- ==> ...(case x of I# x# -> case fw x# of ...)...
512 -- and now the redex (f x) isn't floatable any more
513 -- Similarly, don't apply any rules until after full
514 -- laziness. Notably, list fusion can prevent floating.
517 -- Don't do case-of-case transformations.
518 -- This makes full laziness work better
519 MaxSimplifierIterations max_iter
522 -- Specialisation is best done before full laziness
523 -- so that overloaded functions have all their dictionary lambdas manifest
526 if full_laziness then CoreDoFloatOutwards (FloatOutSw False False)
531 CoreDoSimplify (SimplPhase 2) [
532 -- Want to run with inline phase 2 after the specialiser to give
533 -- maximum chance for fusion to work before we inline build/augment
534 -- in phase 1. This made a difference in 'ansi' where an
535 -- overloaded function wasn't inlined till too late.
536 MaxSimplifierIterations max_iter
538 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
540 CoreDoSimplify (SimplPhase 1) [
541 -- Need inline-phase2 here so that build/augment get
542 -- inlined. I found that spectral/hartel/genfft lost some useful
543 -- strictness in the function sumcode' if augment is not inlined
544 -- before strictness analysis runs
545 MaxSimplifierIterations max_iter
547 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
549 CoreDoSimplify (SimplPhase 0) [
550 -- Phase 0: allow all Ids to be inlined now
551 -- This gets foldr inlined before strictness analysis
553 MaxSimplifierIterations 3
554 -- At least 3 iterations because otherwise we land up with
555 -- huge dead expressions because of an infelicity in the
557 -- let k = BIG in foldr k z xs
558 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
559 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
563 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
565 #ifdef OLD_STRICTNESS
568 if strictness then CoreDoStrictness else CoreDoNothing,
572 CoreDoSimplify (SimplPhase 0) [
573 MaxSimplifierIterations max_iter
576 if full_laziness then
577 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
578 True) -- Float constants
580 -- nofib/spectral/hartel/wang doubles in speed if you
581 -- do full laziness late in the day. It only happens
582 -- after fusion and other stuff, so the early pass doesn't
583 -- catch it. For the record, the redex is
584 -- f_el22 (f_el21 r_midblock)
587 -- We want CSE to follow the final full-laziness pass, because it may
588 -- succeed in commoning up things floated out by full laziness.
589 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
591 if cse then CoreCSE else CoreDoNothing,
595 -- Case-liberation for -O2. This should be after
596 -- strictness analysis and the simplification which follows it.
598 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
600 if opt_level >= 2 then
604 if opt_level >= 2 then
609 -- Final clean-up simplification:
610 CoreDoSimplify (SimplPhase 0) [
611 MaxSimplifierIterations max_iter
616 %************************************************************************
618 \subsection{Warnings}
620 %************************************************************************
624 = [ Opt_WarnDeprecations,
625 Opt_WarnOverlappingPatterns,
626 Opt_WarnMissingFields,
627 Opt_WarnMissingMethods,
628 Opt_WarnDuplicateExports
632 = standardWarnings ++
633 [ Opt_WarnUnusedBinds,
634 Opt_WarnUnusedMatches,
635 Opt_WarnUnusedImports,
636 Opt_WarnIncompletePatterns,
642 [ Opt_WarnTypeDefaults,
643 Opt_WarnNameShadowing,
650 %************************************************************************
652 \subsection{Classifying command-line options}
654 %************************************************************************
657 -- v_Statis_hsc_opts is here to avoid a circular dependency with
659 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
661 lookUp :: FastString -> Bool
662 lookup_def_int :: String -> Int -> Int
663 lookup_def_float :: String -> Float -> Float
664 lookup_str :: String -> Maybe String
666 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
667 packed_static_opts = map mkFastString unpacked_static_opts
669 lookUp sw = sw `elem` packed_static_opts
671 -- (lookup_str "foo") looks for the flag -foo=X or -fooX,
672 -- and returns the string X
674 = case firstJust (map (startsWith sw) unpacked_static_opts) of
675 Just ('=' : str) -> Just str
679 lookup_def_int sw def = case (lookup_str sw) of
680 Nothing -> def -- Use default
681 Just xx -> try_read sw xx
683 lookup_def_float sw def = case (lookup_str sw) of
684 Nothing -> def -- Use default
685 Just xx -> try_read sw xx
688 try_read :: Read a => String -> String -> a
689 -- (try_read sw str) tries to read s; if it fails, it
690 -- bleats about flag sw
693 ((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
694 [] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))
695 -- ToDo: hack alert. We should really parse the arugments
696 -- and announce errors in a more civilised way.
700 Putting the compiler options into temporary at-files
701 may turn out to be necessary later on if we turn hsc into
702 a pure Win32 application where I think there's a command-line
703 length limit of 255. unpacked_opts understands the @ option.
705 unpacked_opts :: [String]
709 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
711 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
716 %************************************************************************
718 \subsection{Static options}
720 %************************************************************************
724 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
725 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
728 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
729 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
730 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
731 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
732 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
735 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
736 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
737 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
738 opt_Parallel = lookUp FSLIT("-fparallel")
739 opt_SMP = lookUp FSLIT("-fsmp")
740 opt_Flatten = lookUp FSLIT("-fflatten")
743 opt_NoStateHack = lookUp FSLIT("-fno-state-hack")
744 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
745 opt_CprOff = lookUp FSLIT("-fcpr-off")
746 opt_RulesOff = lookUp FSLIT("-frules-off")
747 -- Switch off CPR analysis in the new demand analyser
748 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
749 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
751 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
752 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
753 opt_GranMacros = lookUp FSLIT("-fgransim")
754 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
755 opt_HistorySize = lookup_def_int "-fhistory-size" 20
756 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
757 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
759 -- Simplifier switches
760 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
761 -- NoPreInlining is there just to see how bad things
762 -- get if you don't do it!
763 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
766 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
767 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
768 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
769 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
770 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
772 opt_UF_DearOp = ( 4 :: Int)
774 opt_Static = lookUp FSLIT("-static")
775 opt_Unregisterised = lookUp FSLIT("-funregisterised")
776 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
778 -- Include full span info in error messages, instead of just the start position.
779 opt_ErrorSpans = lookUp FSLIT("-ferror-spans")
781 opt_PIC = lookUp FSLIT("-fPIC")
784 %************************************************************************
786 \subsection{List of static hsc flags}
788 %************************************************************************
793 "fauto-sccs-on-all-toplevs",
794 "fauto-sccs-on-exported-toplevs",
795 "fauto-sccs-on-individual-cafs",
796 "fauto-sccs-on-dicts",
801 "firrefutable-tuples",
807 "femit-extern-decls",
808 "fglobalise-toplev-names",
810 "fno-hi-version-check",
812 "fno-method-sharing",
817 "funfolding-update-in-place",
827 || any (flip prefixMatch f) [
829 "fliberate-case-threshold",
832 "funfolding-creation-threshold",
833 "funfolding-use-threshold",
834 "funfolding-fun-discount",
835 "funfolding-keeness-factor"
839 %************************************************************************
841 \subsection{Misc functions for command-line options}
843 %************************************************************************
848 startsWith :: String -> String -> Maybe String
849 -- startsWith pfx (pfx++rest) = Just rest
851 startsWith [] str = Just str
852 startsWith (c:cs) (s:ss)
853 = if c /= s then Nothing else startsWith cs ss
854 startsWith _ [] = Nothing