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_HscLang, -- DynFlags -> HscLang
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 Constants -- Default values for some flags
95 import FastString ( FastString, mkFastString )
97 import Maybes ( firstJust )
99 import Panic ( ghcError, GhcException(UsageError) )
101 import DATA_IOREF ( IORef, readIORef )
102 import UNSAFE_IO ( unsafePerformIO )
105 %************************************************************************
107 \subsection{Command-line options}
109 %************************************************************************
111 The hsc command-line options are split into two categories:
116 Static flags are represented by top-level values of type Bool or Int,
117 for example. They therefore have the same value throughout the
120 Dynamic flags are represented by an abstract type, DynFlags, which is
121 passed into hsc by the compilation manager for every compilation.
122 Dynamic flags are those that change on a per-compilation basis,
123 perhaps because they may be present in the OPTIONS pragma at the top
126 Other flag-related blurb:
128 A list of {\em ToDo}s is things to be done in a particular part of
129 processing. A (fictitious) example for the Core-to-Core simplifier
130 might be: run the simplifier, then run the strictness analyser, then
131 run the simplifier again (three ``todos'').
133 There are three ``to-do processing centers'' at the moment. In the
134 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
135 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
136 (\tr{simplStg/SimplStg.lhs}).
138 %************************************************************************
140 \subsection{Datatypes associated with command-line options}
142 %************************************************************************
145 data CoreToDo -- These are diff core-to-core passes,
146 -- which may be invoked in any order,
147 -- as many times as you like.
149 = CoreDoSimplify -- The core-to-core simplifier.
152 -- Each run of the simplifier can take a different
153 -- set of simplifier-specific flags.
155 | CoreDoFloatOutwards FloatOutSwitches
160 | CoreDoWorkerWrapper
163 | CoreDoOldStrictness
166 | CoreDoRuleCheck Int{-CompilerPhase-} String -- Check for non-application of rules
167 -- matching this string
169 | CoreDoNothing -- useful when building up lists of these things
174 = StgDoMassageForProfiling -- should be (next to) last
175 -- There's also setStgVarInfo, but its absolute "lastness"
176 -- is so critical that it is hardwired in (no flag).
181 data SimplifierMode -- See comments in SimplMonad
185 data SimplifierSwitch
186 = MaxSimplifierIterations Int
189 data FloatOutSwitches
190 = FloatOutSw Bool -- True <=> float lambdas to top level
191 Bool -- True <=> float constants to top level,
192 -- even if they do not escape a lambda
195 %************************************************************************
197 \subsection{Dynamic command-line options}
199 %************************************************************************
212 | Opt_D_dump_inlinings
213 | Opt_D_dump_occur_anal
217 | Opt_D_dump_simpl_iterations
226 | Opt_D_dump_worker_wrapper
227 | Opt_D_dump_rn_trace
228 | Opt_D_dump_rn_stats
230 | Opt_D_dump_simpl_stats
231 | Opt_D_dump_tc_trace
232 | Opt_D_dump_if_trace
237 | Opt_D_verbose_core2core
238 | Opt_D_verbose_stg2stg
240 | Opt_D_dump_hi_diffs
241 | Opt_D_dump_minimal_imports
246 | Opt_WarnIsError -- -Werror; makes warnings fatal
247 | Opt_WarnDuplicateExports
249 | Opt_WarnIncompletePatterns
250 | Opt_WarnIncompletePatternsRecUpd
251 | Opt_WarnMissingFields
252 | Opt_WarnMissingMethods
253 | Opt_WarnMissingSigs
254 | Opt_WarnNameShadowing
255 | Opt_WarnOverlappingPatterns
256 | Opt_WarnSimplePatterns
257 | Opt_WarnTypeDefaults
258 | Opt_WarnUnusedBinds
259 | Opt_WarnUnusedImports
260 | Opt_WarnUnusedMatches
261 | Opt_WarnDeprecations
262 | Opt_WarnDodgyImports
265 | Opt_AllowOverlappingInstances
266 | Opt_AllowUndecidableInstances
267 | Opt_AllowIncoherentInstances
268 | Opt_NoMonomorphismRestriction
271 | Opt_PArr -- syntactic support for parallel arrays
272 | Opt_Arrows -- Arrow-notation syntax
276 | Opt_NoImplicitPrelude
282 | Opt_IgnoreInterfacePragmas
283 | Opt_OmitInterfacePragmas
284 | Opt_DoLambdaEtaExpansion
288 | Opt_UnboxStrictFields
292 data DynFlags = DynFlags {
293 coreToDo :: Maybe [CoreToDo], -- reserved for use with -Ofile
294 stgToDo :: [StgToDo],
296 hscOutName :: String, -- name of the output file
297 hscStubHOutName :: String, -- name of the .stub_h output file
298 hscStubCOutName :: String, -- name of the .stub_c output file
299 extCoreName :: String, -- name of the .core output file
300 verbosity :: Int, -- verbosity level
301 optLevel :: Int, -- optimisation level
302 maxSimplIterations :: Int, -- max simplifier iterations
303 ruleCheck :: Maybe String,
304 cppFlag :: Bool, -- preprocess with cpp?
305 ppFlag :: Bool, -- preprocess with a Haskell Pp?
306 stolen_x86_regs :: Int,
307 cmdlineHcIncludes :: [String], -- -#includes
308 importPaths :: [FilePath],
310 -- options for particular phases
323 extraPkgConfs :: [FilePath],
324 -- The -package-conf flags given on the command line, in the order
327 readUserPkgConf :: Bool,
328 -- Whether or not to read the user package database
329 -- (-no-user-package-conf).
331 packageFlags :: [PackageFlag],
332 -- The -package and -hide-package flags from the command-line
335 pkgState :: PackageState,
342 = ExposePackage String
344 | IgnorePackage String
356 | cGhcWithNativeCodeGen == "YES" &&
357 (prefixMatch "i386" cTARGETPLATFORM ||
358 prefixMatch "sparc" cTARGETPLATFORM ||
359 prefixMatch "powerpc" cTARGETPLATFORM) = HscAsm
362 defaultDynFlags = DynFlags {
363 coreToDo = Nothing, stgToDo = [],
364 hscLang = defaultHscLang,
366 hscStubHOutName = "", hscStubCOutName = "",
370 maxSimplIterations = 4,
375 cmdlineHcIncludes = [],
389 readUserPkgConf = True,
391 pkgState = error "pkgState",
395 -- Generating the helper-functions for
396 -- generics is now on by default
398 -- strictness is on by default, but this only
400 Opt_CSE, -- similarly for CSE.
401 Opt_FullLaziness, -- ...and for full laziness
403 Opt_DoLambdaEtaExpansion,
404 -- This one is important for a tiresome reason:
405 -- we want to make sure that the bindings for data
406 -- constructors are eta-expanded. This is probably
407 -- a good thing anyway, but it seems fragile.
409 -- and the default no-optimisation options:
410 Opt_IgnoreInterfacePragmas,
411 Opt_OmitInterfacePragmas
413 ] ++ standardWarnings
419 0 | print errors & warnings only
420 1 | minimal verbosity: print "compiling M ... done." for each module.
421 2 | equivalent to -dshow-passes
422 3 | equivalent to existing "ghc -v"
423 4 | "ghc -v -ddump-most"
424 5 | "ghc -v -ddump-all"
427 dopt :: DynFlag -> DynFlags -> Bool
428 dopt f dflags = f `elem` (flags dflags)
430 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
431 dopt_CoreToDo = coreToDo
433 dopt_StgToDo :: DynFlags -> [StgToDo]
434 dopt_StgToDo = stgToDo
436 dopt_OutName :: DynFlags -> String
437 dopt_OutName = hscOutName
439 dopt_HscLang :: DynFlags -> HscLang
440 dopt_HscLang = hscLang
442 dopt_set :: DynFlags -> DynFlag -> DynFlags
443 dopt_set dfs f = dfs{ flags = f : flags dfs }
445 dopt_unset :: DynFlags -> DynFlag -> DynFlags
446 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
448 getOpts :: DynFlags -> (DynFlags -> [a]) -> [a]
449 -- We add to the options from the front, so we need to reverse the list
450 getOpts dflags opts = reverse (opts dflags)
453 | verbosity dflags >= 3 = "-v"
456 -----------------------------------------------------------------------------
457 -- Setting the optimisation level
461 then dfs2{ hscLang = HscC, optLevel = n } -- turn on -fvia-C with -O
462 else dfs2{ optLevel = n }
464 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
465 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
468 | n == 0 = opt_0_dopts
469 | otherwise = opt_1_dopts
472 | n == 0 = opt_1_dopts
473 | otherwise = opt_0_dopts
476 Opt_IgnoreInterfacePragmas,
477 Opt_OmitInterfacePragmas
486 -- Core-to-core phases:
488 buildCoreToDo :: DynFlags -> [CoreToDo]
489 buildCoreToDo dflags = core_todo
491 opt_level = optLevel dflags
492 max_iter = maxSimplIterations dflags
493 strictness = dopt Opt_Strictness dflags
494 full_laziness = dopt Opt_FullLaziness dflags
495 cse = dopt Opt_CSE dflags
496 rule_check = ruleCheck dflags
499 if opt_level == 0 then
501 CoreDoSimplify (SimplPhase 0) [
502 MaxSimplifierIterations max_iter
506 else {- opt_level >= 1 -} [
508 -- initial simplify: mk specialiser happy: minimum effort please
509 CoreDoSimplify SimplGently [
511 -- Don't inline anything till full laziness has bitten
512 -- In particular, inlining wrappers inhibits floating
513 -- e.g. ...(case f x of ...)...
514 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
515 -- ==> ...(case x of I# x# -> case fw x# of ...)...
516 -- and now the redex (f x) isn't floatable any more
517 -- Similarly, don't apply any rules until after full
518 -- laziness. Notably, list fusion can prevent floating.
521 -- Don't do case-of-case transformations.
522 -- This makes full laziness work better
523 MaxSimplifierIterations max_iter
526 -- Specialisation is best done before full laziness
527 -- so that overloaded functions have all their dictionary lambdas manifest
530 if full_laziness then CoreDoFloatOutwards (FloatOutSw False False)
535 CoreDoSimplify (SimplPhase 2) [
536 -- Want to run with inline phase 2 after the specialiser to give
537 -- maximum chance for fusion to work before we inline build/augment
538 -- in phase 1. This made a difference in 'ansi' where an
539 -- overloaded function wasn't inlined till too late.
540 MaxSimplifierIterations max_iter
542 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
544 CoreDoSimplify (SimplPhase 1) [
545 -- Need inline-phase2 here so that build/augment get
546 -- inlined. I found that spectral/hartel/genfft lost some useful
547 -- strictness in the function sumcode' if augment is not inlined
548 -- before strictness analysis runs
549 MaxSimplifierIterations max_iter
551 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
553 CoreDoSimplify (SimplPhase 0) [
554 -- Phase 0: allow all Ids to be inlined now
555 -- This gets foldr inlined before strictness analysis
557 MaxSimplifierIterations 3
558 -- At least 3 iterations because otherwise we land up with
559 -- huge dead expressions because of an infelicity in the
561 -- let k = BIG in foldr k z xs
562 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
563 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
567 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
569 #ifdef OLD_STRICTNESS
572 if strictness then CoreDoStrictness else CoreDoNothing,
576 CoreDoSimplify (SimplPhase 0) [
577 MaxSimplifierIterations max_iter
580 if full_laziness then
581 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
582 True) -- Float constants
584 -- nofib/spectral/hartel/wang doubles in speed if you
585 -- do full laziness late in the day. It only happens
586 -- after fusion and other stuff, so the early pass doesn't
587 -- catch it. For the record, the redex is
588 -- f_el22 (f_el21 r_midblock)
591 -- We want CSE to follow the final full-laziness pass, because it may
592 -- succeed in commoning up things floated out by full laziness.
593 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
595 if cse then CoreCSE else CoreDoNothing,
599 -- Case-liberation for -O2. This should be after
600 -- strictness analysis and the simplification which follows it.
602 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
604 if opt_level >= 2 then
608 if opt_level >= 2 then
613 -- Final clean-up simplification:
614 CoreDoSimplify (SimplPhase 0) [
615 MaxSimplifierIterations max_iter
620 %************************************************************************
622 \subsection{Warnings}
624 %************************************************************************
628 = [ Opt_WarnDeprecations,
629 Opt_WarnOverlappingPatterns,
630 Opt_WarnMissingFields,
631 Opt_WarnMissingMethods,
632 Opt_WarnDuplicateExports
636 = standardWarnings ++
637 [ Opt_WarnUnusedBinds,
638 Opt_WarnUnusedMatches,
639 Opt_WarnUnusedImports,
640 Opt_WarnIncompletePatterns,
646 [ Opt_WarnTypeDefaults,
647 Opt_WarnNameShadowing,
653 %************************************************************************
655 \subsection{Classifying command-line options}
657 %************************************************************************
660 -- v_Statis_hsc_opts is here to avoid a circular dependency with
662 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
664 lookUp :: FastString -> Bool
665 lookup_def_int :: String -> Int -> Int
666 lookup_def_float :: String -> Float -> Float
667 lookup_str :: String -> Maybe String
669 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
670 packed_static_opts = map mkFastString unpacked_static_opts
672 lookUp sw = sw `elem` packed_static_opts
674 -- (lookup_str "foo") looks for the flag -foo=X or -fooX,
675 -- and returns the string X
677 = case firstJust (map (startsWith sw) unpacked_static_opts) of
678 Just ('=' : str) -> Just str
682 lookup_def_int sw def = case (lookup_str sw) of
683 Nothing -> def -- Use default
684 Just xx -> try_read sw xx
686 lookup_def_float sw def = case (lookup_str sw) of
687 Nothing -> def -- Use default
688 Just xx -> try_read sw xx
691 try_read :: Read a => String -> String -> a
692 -- (try_read sw str) tries to read s; if it fails, it
693 -- bleats about flag sw
696 ((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
697 [] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))
698 -- ToDo: hack alert. We should really parse the arugments
699 -- and announce errors in a more civilised way.
703 Putting the compiler options into temporary at-files
704 may turn out to be necessary later on if we turn hsc into
705 a pure Win32 application where I think there's a command-line
706 length limit of 255. unpacked_opts understands the @ option.
708 unpacked_opts :: [String]
712 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
714 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
719 %************************************************************************
721 \subsection{Static options}
723 %************************************************************************
727 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
728 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
731 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
732 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
733 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
734 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
735 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
738 opt_AllStrict = lookUp FSLIT("-fall-strict")
739 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
740 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
741 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
742 opt_Parallel = lookUp FSLIT("-fparallel")
743 opt_SMP = lookUp FSLIT("-fsmp")
744 opt_Flatten = lookUp FSLIT("-fflatten")
747 opt_NoStateHack = lookUp FSLIT("-fno-state-hack")
748 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
749 opt_CprOff = lookUp FSLIT("-fcpr-off")
750 opt_RulesOff = lookUp FSLIT("-frules-off")
751 -- Switch off CPR analysis in the new demand analyser
752 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
753 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
755 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
756 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
757 opt_GranMacros = lookUp FSLIT("-fgransim")
758 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
759 opt_HistorySize = lookup_def_int "-fhistory-size" 20
760 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
761 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
763 -- Simplifier switches
764 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
765 -- NoPreInlining is there just to see how bad things
766 -- get if you don't do it!
767 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
770 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
771 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
772 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
773 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
774 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
776 opt_UF_DearOp = ( 4 :: Int)
778 opt_Static = lookUp FSLIT("-static")
779 opt_Unregisterised = lookUp FSLIT("-funregisterised")
780 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
782 -- Include full span info in error messages, instead of just the start position.
783 opt_ErrorSpans = lookUp FSLIT("-ferror-spans")
785 opt_PIC = lookUp FSLIT("-fPIC")
788 %************************************************************************
790 \subsection{List of static hsc flags}
792 %************************************************************************
797 "fauto-sccs-on-all-toplevs",
798 "fauto-sccs-on-exported-toplevs",
799 "fauto-sccs-on-individual-cafs",
800 "fauto-sccs-on-dicts",
805 "firrefutable-tuples",
811 "femit-extern-decls",
812 "fglobalise-toplev-names",
814 "fno-hi-version-check",
816 "fno-method-sharing",
821 "funfolding-update-in-place",
831 || any (flip prefixMatch f) [
833 "fliberate-case-threshold",
836 "funfolding-creation-threshold",
837 "funfolding-use-threshold",
838 "funfolding-fun-discount",
839 "funfolding-keeness-factor"
843 %************************************************************************
845 \subsection{Misc functions for command-line options}
847 %************************************************************************
852 startsWith :: String -> String -> Maybe String
853 -- startsWith pfx (pfx++rest) = Just rest
855 startsWith [] str = Just str
856 startsWith (c:cs) (s:ss)
857 = if c /= s then Nothing else startsWith cs ss
858 startsWith _ [] = Nothing
860 endsWith :: String -> String -> Maybe String
862 = case (startsWith (reverse cs) (reverse ss)) of
864 Just rs -> Just (reverse rs)