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_MonomorphismRestriction
271 | Opt_PArr -- syntactic support for parallel arrays
272 | Opt_Arrows -- Arrow-notation syntax
276 | Opt_ImplicitPrelude
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 Opt_MonomorphismRestriction,
397 -- Generating the helper-functions for
398 -- generics is now on by default
400 -- strictness is on by default, but this only
402 Opt_CSE, -- similarly for CSE.
403 Opt_FullLaziness, -- ...and for full laziness
405 Opt_DoLambdaEtaExpansion,
406 -- This one is important for a tiresome reason:
407 -- we want to make sure that the bindings for data
408 -- constructors are eta-expanded. This is probably
409 -- a good thing anyway, but it seems fragile.
411 -- and the default no-optimisation options:
412 Opt_IgnoreInterfacePragmas,
413 Opt_OmitInterfacePragmas
415 ] ++ standardWarnings
421 0 | print errors & warnings only
422 1 | minimal verbosity: print "compiling M ... done." for each module.
423 2 | equivalent to -dshow-passes
424 3 | equivalent to existing "ghc -v"
425 4 | "ghc -v -ddump-most"
426 5 | "ghc -v -ddump-all"
429 dopt :: DynFlag -> DynFlags -> Bool
430 dopt f dflags = f `elem` (flags dflags)
432 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
433 dopt_CoreToDo = coreToDo
435 dopt_StgToDo :: DynFlags -> [StgToDo]
436 dopt_StgToDo = stgToDo
438 dopt_OutName :: DynFlags -> String
439 dopt_OutName = hscOutName
441 dopt_HscLang :: DynFlags -> HscLang
442 dopt_HscLang = hscLang
444 dopt_set :: DynFlags -> DynFlag -> DynFlags
445 dopt_set dfs f = dfs{ flags = f : flags dfs }
447 dopt_unset :: DynFlags -> DynFlag -> DynFlags
448 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
450 getOpts :: DynFlags -> (DynFlags -> [a]) -> [a]
451 -- We add to the options from the front, so we need to reverse the list
452 getOpts dflags opts = reverse (opts dflags)
455 | verbosity dflags >= 3 = "-v"
458 -----------------------------------------------------------------------------
459 -- Setting the optimisation level
463 then dfs2{ hscLang = HscC, optLevel = n } -- turn on -fvia-C with -O
464 else dfs2{ optLevel = n }
466 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
467 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
470 | n == 0 = opt_0_dopts
471 | otherwise = opt_1_dopts
474 | n == 0 = opt_1_dopts
475 | otherwise = opt_0_dopts
478 Opt_IgnoreInterfacePragmas,
479 Opt_OmitInterfacePragmas
488 -- Core-to-core phases:
490 buildCoreToDo :: DynFlags -> [CoreToDo]
491 buildCoreToDo dflags = core_todo
493 opt_level = optLevel dflags
494 max_iter = maxSimplIterations dflags
495 strictness = dopt Opt_Strictness dflags
496 full_laziness = dopt Opt_FullLaziness dflags
497 cse = dopt Opt_CSE dflags
498 rule_check = ruleCheck dflags
501 if opt_level == 0 then
503 CoreDoSimplify (SimplPhase 0) [
504 MaxSimplifierIterations max_iter
508 else {- opt_level >= 1 -} [
510 -- initial simplify: mk specialiser happy: minimum effort please
511 CoreDoSimplify SimplGently [
513 -- Don't inline anything till full laziness has bitten
514 -- In particular, inlining wrappers inhibits floating
515 -- e.g. ...(case f x of ...)...
516 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
517 -- ==> ...(case x of I# x# -> case fw x# of ...)...
518 -- and now the redex (f x) isn't floatable any more
519 -- Similarly, don't apply any rules until after full
520 -- laziness. Notably, list fusion can prevent floating.
523 -- Don't do case-of-case transformations.
524 -- This makes full laziness work better
525 MaxSimplifierIterations max_iter
528 -- Specialisation is best done before full laziness
529 -- so that overloaded functions have all their dictionary lambdas manifest
532 if full_laziness then CoreDoFloatOutwards (FloatOutSw False False)
537 CoreDoSimplify (SimplPhase 2) [
538 -- Want to run with inline phase 2 after the specialiser to give
539 -- maximum chance for fusion to work before we inline build/augment
540 -- in phase 1. This made a difference in 'ansi' where an
541 -- overloaded function wasn't inlined till too late.
542 MaxSimplifierIterations max_iter
544 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
546 CoreDoSimplify (SimplPhase 1) [
547 -- Need inline-phase2 here so that build/augment get
548 -- inlined. I found that spectral/hartel/genfft lost some useful
549 -- strictness in the function sumcode' if augment is not inlined
550 -- before strictness analysis runs
551 MaxSimplifierIterations max_iter
553 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
555 CoreDoSimplify (SimplPhase 0) [
556 -- Phase 0: allow all Ids to be inlined now
557 -- This gets foldr inlined before strictness analysis
559 MaxSimplifierIterations 3
560 -- At least 3 iterations because otherwise we land up with
561 -- huge dead expressions because of an infelicity in the
563 -- let k = BIG in foldr k z xs
564 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
565 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
569 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
571 #ifdef OLD_STRICTNESS
574 if strictness then CoreDoStrictness else CoreDoNothing,
578 CoreDoSimplify (SimplPhase 0) [
579 MaxSimplifierIterations max_iter
582 if full_laziness then
583 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
584 True) -- Float constants
586 -- nofib/spectral/hartel/wang doubles in speed if you
587 -- do full laziness late in the day. It only happens
588 -- after fusion and other stuff, so the early pass doesn't
589 -- catch it. For the record, the redex is
590 -- f_el22 (f_el21 r_midblock)
593 -- We want CSE to follow the final full-laziness pass, because it may
594 -- succeed in commoning up things floated out by full laziness.
595 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
597 if cse then CoreCSE else CoreDoNothing,
601 -- Case-liberation for -O2. This should be after
602 -- strictness analysis and the simplification which follows it.
604 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
606 if opt_level >= 2 then
610 if opt_level >= 2 then
615 -- Final clean-up simplification:
616 CoreDoSimplify (SimplPhase 0) [
617 MaxSimplifierIterations max_iter
622 %************************************************************************
624 \subsection{Warnings}
626 %************************************************************************
630 = [ Opt_WarnDeprecations,
631 Opt_WarnOverlappingPatterns,
632 Opt_WarnMissingFields,
633 Opt_WarnMissingMethods,
634 Opt_WarnDuplicateExports
638 = standardWarnings ++
639 [ Opt_WarnUnusedBinds,
640 Opt_WarnUnusedMatches,
641 Opt_WarnUnusedImports,
642 Opt_WarnIncompletePatterns,
648 [ Opt_WarnTypeDefaults,
649 Opt_WarnNameShadowing,
655 %************************************************************************
657 \subsection{Classifying command-line options}
659 %************************************************************************
662 -- v_Statis_hsc_opts is here to avoid a circular dependency with
664 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
666 lookUp :: FastString -> Bool
667 lookup_def_int :: String -> Int -> Int
668 lookup_def_float :: String -> Float -> Float
669 lookup_str :: String -> Maybe String
671 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
672 packed_static_opts = map mkFastString unpacked_static_opts
674 lookUp sw = sw `elem` packed_static_opts
676 -- (lookup_str "foo") looks for the flag -foo=X or -fooX,
677 -- and returns the string X
679 = case firstJust (map (startsWith sw) unpacked_static_opts) of
680 Just ('=' : str) -> Just str
684 lookup_def_int sw def = case (lookup_str sw) of
685 Nothing -> def -- Use default
686 Just xx -> try_read sw xx
688 lookup_def_float sw def = case (lookup_str sw) of
689 Nothing -> def -- Use default
690 Just xx -> try_read sw xx
693 try_read :: Read a => String -> String -> a
694 -- (try_read sw str) tries to read s; if it fails, it
695 -- bleats about flag sw
698 ((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
699 [] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))
700 -- ToDo: hack alert. We should really parse the arugments
701 -- and announce errors in a more civilised way.
705 Putting the compiler options into temporary at-files
706 may turn out to be necessary later on if we turn hsc into
707 a pure Win32 application where I think there's a command-line
708 length limit of 255. unpacked_opts understands the @ option.
710 unpacked_opts :: [String]
714 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
716 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
721 %************************************************************************
723 \subsection{Static options}
725 %************************************************************************
729 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
730 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
733 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
734 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
735 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
736 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
737 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
740 opt_AllStrict = lookUp FSLIT("-fall-strict")
741 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
742 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
743 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
744 opt_Parallel = lookUp FSLIT("-fparallel")
745 opt_SMP = lookUp FSLIT("-fsmp")
746 opt_Flatten = lookUp FSLIT("-fflatten")
749 opt_NoStateHack = lookUp FSLIT("-fno-state-hack")
750 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
751 opt_CprOff = lookUp FSLIT("-fcpr-off")
752 opt_RulesOff = lookUp FSLIT("-frules-off")
753 -- Switch off CPR analysis in the new demand analyser
754 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
755 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
757 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
758 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
759 opt_GranMacros = lookUp FSLIT("-fgransim")
760 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
761 opt_HistorySize = lookup_def_int "-fhistory-size" 20
762 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
763 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
765 -- Simplifier switches
766 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
767 -- NoPreInlining is there just to see how bad things
768 -- get if you don't do it!
769 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
772 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
773 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
774 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
775 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
776 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
778 opt_UF_DearOp = ( 4 :: Int)
780 opt_Static = lookUp FSLIT("-static")
781 opt_Unregisterised = lookUp FSLIT("-funregisterised")
782 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
784 -- Include full span info in error messages, instead of just the start position.
785 opt_ErrorSpans = lookUp FSLIT("-ferror-spans")
787 opt_PIC = lookUp FSLIT("-fPIC")
790 %************************************************************************
792 \subsection{List of static hsc flags}
794 %************************************************************************
799 "fauto-sccs-on-all-toplevs",
800 "fauto-sccs-on-exported-toplevs",
801 "fauto-sccs-on-individual-cafs",
802 "fauto-sccs-on-dicts",
807 "firrefutable-tuples",
813 "femit-extern-decls",
814 "fglobalise-toplev-names",
816 "fno-hi-version-check",
818 "fno-method-sharing",
823 "funfolding-update-in-place",
833 || any (flip prefixMatch f) [
835 "fliberate-case-threshold",
838 "funfolding-creation-threshold",
839 "funfolding-use-threshold",
840 "funfolding-fun-discount",
841 "funfolding-keeness-factor"
845 %************************************************************************
847 \subsection{Misc functions for command-line options}
849 %************************************************************************
854 startsWith :: String -> String -> Maybe String
855 -- startsWith pfx (pfx++rest) = Just rest
857 startsWith [] str = Just str
858 startsWith (c:cs) (s:ss)
859 = if c /= s then Nothing else startsWith cs ss
860 startsWith _ [] = Nothing
862 endsWith :: String -> String -> Maybe String
864 = case (startsWith (reverse cs) (reverse ss)) of
866 Just rs -> Just (reverse rs)