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 dopt, -- DynFlag -> DynFlags -> Bool
24 dopt_set, dopt_unset, -- DynFlags -> DynFlag -> DynFlags
25 dopt_CoreToDo, -- DynFlags -> [CoreToDo]
26 dopt_StgToDo, -- DynFlags -> [StgToDo]
27 dopt_HscLang, -- DynFlags -> HscLang
28 dopt_OutName, -- DynFlags -> String
29 getOpts, -- (DynFlags -> [a]) -> IO [a]
34 -- Manipulating the DynFlags state
35 getDynFlags, -- IO DynFlags
36 setDynFlags, -- DynFlags -> IO ()
37 updDynFlags, -- (DynFlags -> DynFlags) -> IO ()
38 dynFlag, -- (DynFlags -> a) -> IO a
39 setDynFlag, unSetDynFlag, -- DynFlag -> IO ()
40 saveDynFlags, -- IO ()
41 restoreDynFlags, -- IO DynFlags
43 -- sets of warning opts
47 -- Output style options
52 opt_AutoSccsOnAllToplevs,
53 opt_AutoSccsOnExportedToplevs,
54 opt_AutoSccsOnIndividualCafs,
60 opt_MaxContextReductionDepth,
61 opt_IrrefutableTuples,
69 opt_LiberateCaseThreshold,
72 opt_SimplNoPreInlining,
73 opt_SimplExcessPrecision,
77 opt_UF_CreationThreshold,
79 opt_UF_FunAppDiscount,
88 opt_EnsureSplittableC,
98 #include "HsVersions.h"
100 import Constants -- Default values for some flags
102 import FastString ( FastString, mkFastString )
104 import Maybes ( firstJust )
107 import DATA_IOREF ( IORef, readIORef, writeIORef )
108 import UNSAFE_IO ( unsafePerformIO )
111 %************************************************************************
113 \subsection{Command-line options}
115 %************************************************************************
117 The hsc command-line options are split into two categories:
122 Static flags are represented by top-level values of type Bool or Int,
123 for example. They therefore have the same value throughout the
126 Dynamic flags are represented by an abstract type, DynFlags, which is
127 passed into hsc by the compilation manager for every compilation.
128 Dynamic flags are those that change on a per-compilation basis,
129 perhaps because they may be present in the OPTIONS pragma at the top
132 Other flag-related blurb:
134 A list of {\em ToDo}s is things to be done in a particular part of
135 processing. A (fictitious) example for the Core-to-Core simplifier
136 might be: run the simplifier, then run the strictness analyser, then
137 run the simplifier again (three ``todos'').
139 There are three ``to-do processing centers'' at the moment. In the
140 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
141 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
142 (\tr{simplStg/SimplStg.lhs}).
144 %************************************************************************
146 \subsection{Datatypes associated with command-line options}
148 %************************************************************************
151 data CoreToDo -- These are diff core-to-core passes,
152 -- which may be invoked in any order,
153 -- as many times as you like.
155 = CoreDoSimplify -- The core-to-core simplifier.
158 -- Each run of the simplifier can take a different
159 -- set of simplifier-specific flags.
161 | CoreDoFloatOutwards FloatOutSwitches
166 | CoreDoWorkerWrapper
169 | CoreDoOldStrictness
172 | CoreDoRuleCheck Int{-CompilerPhase-} String -- Check for non-application of rules
173 -- matching this string
175 | CoreDoNothing -- useful when building up lists of these things
180 = StgDoMassageForProfiling -- should be (next to) last
181 -- There's also setStgVarInfo, but its absolute "lastness"
182 -- is so critical that it is hardwired in (no flag).
187 data SimplifierMode -- See comments in SimplMonad
191 data SimplifierSwitch
192 = MaxSimplifierIterations Int
195 data FloatOutSwitches
196 = FloatOutSw Bool -- True <=> float lambdas to top level
197 Bool -- True <=> float constants to top level,
198 -- even if they do not escape a lambda
201 %************************************************************************
203 \subsection{Dynamic command-line options}
205 %************************************************************************
218 | Opt_D_dump_inlinings
219 | Opt_D_dump_occur_anal
224 | Opt_D_dump_simpl_iterations
233 | Opt_D_dump_worker_wrapper
234 | Opt_D_dump_rn_trace
235 | Opt_D_dump_rn_stats
237 | Opt_D_dump_simpl_stats
238 | Opt_D_dump_tc_trace
239 | Opt_D_dump_if_trace
244 | Opt_D_verbose_core2core
245 | Opt_D_verbose_stg2stg
247 | Opt_D_dump_hi_diffs
248 | Opt_D_dump_minimal_imports
252 | Opt_WarnIsError -- -Werror; makes warnings fatal
253 | Opt_WarnDuplicateExports
255 | Opt_WarnIncompletePatterns
256 | Opt_WarnMissingFields
257 | Opt_WarnMissingMethods
258 | Opt_WarnMissingSigs
259 | Opt_WarnNameShadowing
260 | Opt_WarnOverlappingPatterns
261 | Opt_WarnSimplePatterns
262 | Opt_WarnTypeDefaults
263 | Opt_WarnUnusedBinds
264 | Opt_WarnUnusedImports
265 | Opt_WarnUnusedMatches
266 | Opt_WarnDeprecations
270 | Opt_AllowOverlappingInstances
271 | Opt_AllowUndecidableInstances
272 | Opt_AllowIncoherentInstances
273 | Opt_NoMonomorphismRestriction
276 | Opt_PArr -- syntactic support for parallel arrays
277 | Opt_Arrows -- Arrow-notation syntax
281 | Opt_NoImplicitPrelude
286 | Opt_IgnoreInterfacePragmas
287 | Opt_OmitInterfacePragmas
288 | Opt_DoLambdaEtaExpansion
292 | Opt_UnboxStrictFields
296 data DynFlags = DynFlags {
297 coreToDo :: Maybe [CoreToDo], -- reserved for use with -Ofile
298 stgToDo :: [StgToDo],
300 hscOutName :: String, -- name of the output file
301 hscStubHOutName :: String, -- name of the .stub_h output file
302 hscStubCOutName :: String, -- name of the .stub_c output file
303 extCoreName :: String, -- name of the .core output file
304 verbosity :: Int, -- verbosity level
305 optLevel :: Int, -- optimisation level
306 maxSimplIterations :: Int, -- max simplifier iterations
307 ruleCheck :: Maybe String,
308 cppFlag :: Bool, -- preprocess with cpp?
309 ppFlag :: Bool, -- preprocess with a Haskell Pp?
310 stolen_x86_regs :: Int,
311 cmdlineHcIncludes :: [String], -- -#includes
313 -- options for particular phases
339 | cGhcWithNativeCodeGen == "YES" &&
340 (prefixMatch "i386" cTARGETPLATFORM ||
341 prefixMatch "sparc" cTARGETPLATFORM ||
342 prefixMatch "powerpc" cTARGETPLATFORM) = HscAsm
345 defaultDynFlags = DynFlags {
346 coreToDo = Nothing, stgToDo = [],
347 hscLang = defaultHscLang,
349 hscStubHOutName = "", hscStubCOutName = "",
353 maxSimplIterations = 4,
358 cmdlineHcIncludes = [],
371 -- Generating the helper-functions for
372 -- generics is now on by default
374 -- strictness is on by default, but this only
377 -- similarly for CSE.
378 Opt_DoLambdaEtaExpansion,
379 -- This one is important for a tiresome reason:
380 -- we want to make sure that the bindings for data
381 -- constructors are eta-expanded. This is probably
382 -- a good thing anyway, but it seems fragile.
384 -- and the default no-optimisation options:
385 Opt_IgnoreInterfacePragmas,
386 Opt_OmitInterfacePragmas
388 ] ++ standardWarnings
394 0 | print errors & warnings only
395 1 | minimal verbosity: print "compiling M ... done." for each module.
396 2 | equivalent to -dshow-passes
397 3 | equivalent to existing "ghc -v"
398 4 | "ghc -v -ddump-most"
399 5 | "ghc -v -ddump-all"
402 dopt :: DynFlag -> DynFlags -> Bool
403 dopt f dflags = f `elem` (flags dflags)
405 dopt_CoreToDo :: DynFlags -> Maybe [CoreToDo]
406 dopt_CoreToDo = coreToDo
408 dopt_StgToDo :: DynFlags -> [StgToDo]
409 dopt_StgToDo = stgToDo
411 dopt_OutName :: DynFlags -> String
412 dopt_OutName = hscOutName
414 dopt_HscLang :: DynFlags -> HscLang
415 dopt_HscLang = hscLang
417 dopt_set :: DynFlags -> DynFlag -> DynFlags
418 dopt_set dfs f = dfs{ flags = f : flags dfs }
420 dopt_unset :: DynFlags -> DynFlag -> DynFlags
421 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
423 getOpts :: (DynFlags -> [a]) -> IO [a]
424 -- We add to the options from the front, so we need to reverse the list
425 getOpts opts = dynFlag opts >>= return . reverse
427 -- we can only switch between HscC, HscAsmm, and HscILX with dynamic flags
428 -- (-fvia-C, -fasm, -filx respectively).
429 setLang l = updDynFlags (\ dfs -> case hscLang dfs of
430 HscC -> dfs{ hscLang = l }
431 HscAsm -> dfs{ hscLang = l }
432 HscILX -> dfs{ hscLang = l }
436 verb <- dynFlag verbosity
437 if verb >= 3 then return "-v" else return ""
439 -----------------------------------------------------------------------------
440 -- Setting the optimisation level
442 setOptLevel :: Int -> IO ()
444 = do dflags <- getDynFlags
445 if hscLang dflags == HscInterpreted && n > 0
446 then putStr "warning: -O conflicts with --interactive; -O ignored.\n"
447 else updDynFlags (setOptLevel' n)
451 then dfs2{ hscLang = HscC, optLevel = n } -- turn on -fvia-C with -O
452 else dfs2{ optLevel = n }
454 dfs1 = foldr (flip dopt_unset) dfs remove_dopts
455 dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
458 | n == 0 = opt_0_dopts
459 | otherwise = opt_1_dopts
462 | n == 0 = opt_1_dopts
463 | otherwise = opt_0_dopts
466 Opt_IgnoreInterfacePragmas,
467 Opt_OmitInterfacePragmas
476 -- Core-to-core phases:
478 buildCoreToDo :: DynFlags -> [CoreToDo]
479 buildCoreToDo dflags = core_todo
481 opt_level = optLevel dflags
482 max_iter = maxSimplIterations dflags
483 strictness = dopt Opt_Strictness dflags
484 cse = dopt Opt_CSE dflags
485 rule_check = ruleCheck dflags
488 if opt_level == 0 then
490 CoreDoSimplify (SimplPhase 0) [
491 MaxSimplifierIterations max_iter
495 else {- opt_level >= 1 -} [
497 -- initial simplify: mk specialiser happy: minimum effort please
498 CoreDoSimplify SimplGently [
500 -- Don't inline anything till full laziness has bitten
501 -- In particular, inlining wrappers inhibits floating
502 -- e.g. ...(case f x of ...)...
503 -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
504 -- ==> ...(case x of I# x# -> case fw x# of ...)...
505 -- and now the redex (f x) isn't floatable any more
506 -- Similarly, don't apply any rules until after full
507 -- laziness. Notably, list fusion can prevent floating.
510 -- Don't do case-of-case transformations.
511 -- This makes full laziness work better
512 MaxSimplifierIterations max_iter
515 -- Specialisation is best done before full laziness
516 -- so that overloaded functions have all their dictionary lambdas manifest
519 CoreDoFloatOutwards (FloatOutSw False False),
522 CoreDoSimplify (SimplPhase 2) [
523 -- Want to run with inline phase 2 after the specialiser to give
524 -- maximum chance for fusion to work before we inline build/augment
525 -- in phase 1. This made a difference in 'ansi' where an
526 -- overloaded function wasn't inlined till too late.
527 MaxSimplifierIterations max_iter
529 case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
531 CoreDoSimplify (SimplPhase 1) [
532 -- Need inline-phase2 here so that build/augment get
533 -- inlined. I found that spectral/hartel/genfft lost some useful
534 -- strictness in the function sumcode' if augment is not inlined
535 -- before strictness analysis runs
536 MaxSimplifierIterations max_iter
538 case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
540 CoreDoSimplify (SimplPhase 0) [
541 -- Phase 0: allow all Ids to be inlined now
542 -- This gets foldr inlined before strictness analysis
544 MaxSimplifierIterations 3
545 -- At least 3 iterations because otherwise we land up with
546 -- huge dead expressions because of an infelicity in the
548 -- let k = BIG in foldr k z xs
549 -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
550 -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
554 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
556 #ifdef OLD_STRICTNESS
559 if strictness then CoreDoStrictness else CoreDoNothing,
563 CoreDoSimplify (SimplPhase 0) [
564 MaxSimplifierIterations max_iter
567 CoreDoFloatOutwards (FloatOutSw False -- Not lambdas
568 True), -- Float constants
569 -- nofib/spectral/hartel/wang doubles in speed if you
570 -- do full laziness late in the day. It only happens
571 -- after fusion and other stuff, so the early pass doesn't
572 -- catch it. For the record, the redex is
573 -- f_el22 (f_el21 r_midblock)
576 -- We want CSE to follow the final full-laziness pass, because it may
577 -- succeed in commoning up things floated out by full laziness.
578 -- CSE used to rely on the no-shadowing invariant, but it doesn't any more
580 if cse then CoreCSE else CoreDoNothing,
584 -- Case-liberation for -O2. This should be after
585 -- strictness analysis and the simplification which follows it.
587 case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
589 if opt_level >= 2 then
593 if opt_level >= 2 then
598 -- Final clean-up simplification:
599 CoreDoSimplify (SimplPhase 0) [
600 MaxSimplifierIterations max_iter
604 -- --------------------------------------------------------------------------
605 -- Mess about with the mutable variables holding the dynamic arguments
608 -- is the "baseline" dynamic flags, initialised from
609 -- the defaults and command line options, and updated by the
610 -- ':s' command in GHCi.
613 -- is the dynamic flags for the current compilation. It is reset
614 -- to the value of v_InitDynFlags before each compilation, then
615 -- updated by reading any OPTIONS pragma in the current module.
617 GLOBAL_VAR(v_InitDynFlags, defaultDynFlags, DynFlags)
618 GLOBAL_VAR(v_DynFlags, defaultDynFlags, DynFlags)
620 setDynFlags :: DynFlags -> IO ()
621 setDynFlags dfs = writeIORef v_DynFlags dfs
623 saveDynFlags :: IO ()
624 saveDynFlags = do dfs <- readIORef v_DynFlags
625 writeIORef v_InitDynFlags dfs
627 restoreDynFlags :: IO DynFlags
628 restoreDynFlags = do dfs <- readIORef v_InitDynFlags
629 writeIORef v_DynFlags dfs
632 getDynFlags :: IO DynFlags
633 getDynFlags = readIORef v_DynFlags
635 updDynFlags :: (DynFlags -> DynFlags) -> IO ()
636 updDynFlags f = do dfs <- readIORef v_DynFlags
637 writeIORef v_DynFlags (f dfs)
639 dynFlag :: (DynFlags -> a) -> IO a
640 dynFlag f = do dflags <- readIORef v_DynFlags; return (f dflags)
642 setDynFlag, unSetDynFlag :: DynFlag -> IO ()
643 setDynFlag f = updDynFlags (\dfs -> dopt_set dfs f)
644 unSetDynFlag f = updDynFlags (\dfs -> dopt_unset dfs f)
648 %************************************************************************
650 \subsection{Warnings}
652 %************************************************************************
656 = [ Opt_WarnDeprecations,
657 Opt_WarnOverlappingPatterns,
658 Opt_WarnMissingFields,
659 Opt_WarnMissingMethods,
660 Opt_WarnDuplicateExports
664 = standardWarnings ++
665 [ Opt_WarnUnusedBinds,
666 Opt_WarnUnusedMatches,
667 Opt_WarnUnusedImports,
668 Opt_WarnIncompletePatterns,
674 [ Opt_WarnTypeDefaults,
675 Opt_WarnNameShadowing,
681 %************************************************************************
683 \subsection{Classifying command-line options}
685 %************************************************************************
688 -- v_Statis_hsc_opts is here to avoid a circular dependency with
690 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
692 lookUp :: FastString -> Bool
693 lookup_int :: String -> Maybe Int
694 lookup_def_int :: String -> Int -> Int
695 lookup_def_float :: String -> Float -> Float
696 lookup_str :: String -> Maybe String
698 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
699 packed_static_opts = map mkFastString unpacked_static_opts
701 lookUp sw = sw `elem` packed_static_opts
703 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
705 lookup_int sw = case (lookup_str sw) of
707 Just xx -> Just (read xx)
709 lookup_def_int sw def = case (lookup_str sw) of
710 Nothing -> def -- Use default
713 lookup_def_float sw def = case (lookup_str sw) of
714 Nothing -> def -- Use default
719 Putting the compiler options into temporary at-files
720 may turn out to be necessary later on if we turn hsc into
721 a pure Win32 application where I think there's a command-line
722 length limit of 255. unpacked_opts understands the @ option.
724 unpacked_opts :: [String]
728 map unpackFS argv -- NOT ARGV any more: v_Static_hsc_opts
730 expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
735 %************************************************************************
737 \subsection{Static options}
739 %************************************************************************
743 opt_PprStyle_Debug = lookUp FSLIT("-dppr-debug")
744 opt_PprUserLength = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
747 opt_AutoSccsOnAllToplevs = lookUp FSLIT("-fauto-sccs-on-all-toplevs")
748 opt_AutoSccsOnExportedToplevs = lookUp FSLIT("-fauto-sccs-on-exported-toplevs")
749 opt_AutoSccsOnIndividualCafs = lookUp FSLIT("-fauto-sccs-on-individual-cafs")
750 opt_SccProfilingOn = lookUp FSLIT("-fscc-profiling")
751 opt_DoTickyProfiling = lookUp FSLIT("-fticky-ticky")
754 opt_AllStrict = lookUp FSLIT("-fall-strict")
755 opt_DictsStrict = lookUp FSLIT("-fdicts-strict")
756 opt_IrrefutableTuples = lookUp FSLIT("-firrefutable-tuples")
757 opt_MaxContextReductionDepth = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
758 opt_Parallel = lookUp FSLIT("-fparallel")
759 opt_SMP = lookUp FSLIT("-fsmp")
760 opt_Flatten = lookUp FSLIT("-fflatten")
763 opt_NoMethodSharing = lookUp FSLIT("-fno-method-sharing")
764 opt_CprOff = lookUp FSLIT("-fcpr-off")
765 opt_RulesOff = lookUp FSLIT("-frules-off")
766 -- Switch off CPR analysis in the new demand analyser
767 opt_LiberateCaseThreshold = lookup_def_int "-fliberate-case-threshold" (10::Int)
768 opt_MaxWorkerArgs = lookup_def_int "-fmax-worker-args" (10::Int)
771 The optional '-inpackage=P' flag tells what package
772 we are compiling this module for.
773 The Prelude, for example is compiled with '-inpackage std'
775 opt_InPackage = case lookup_str "-inpackage=" of
776 Just p -> mkFastString p
777 Nothing -> FSLIT("Main") -- The package name if none is specified
779 opt_EmitCExternDecls = lookUp FSLIT("-femit-extern-decls")
780 opt_EnsureSplittableC = lookUp FSLIT("-fglobalise-toplev-names")
781 opt_GranMacros = lookUp FSLIT("-fgransim")
782 opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int
783 opt_HistorySize = lookup_def_int "-fhistory-size" 20
784 opt_OmitBlackHoling = lookUp FSLIT("-dno-black-holing")
785 opt_RuntimeTypes = lookUp FSLIT("-fruntime-types")
787 -- Simplifier switches
788 opt_SimplNoPreInlining = lookUp FSLIT("-fno-pre-inlining")
789 -- NoPreInlining is there just to see how bad things
790 -- get if you don't do it!
791 opt_SimplExcessPrecision = lookUp FSLIT("-fexcess-precision")
794 opt_UF_CreationThreshold = lookup_def_int "-funfolding-creation-threshold" (45::Int)
795 opt_UF_UseThreshold = lookup_def_int "-funfolding-use-threshold" (8::Int) -- Discounts can be big
796 opt_UF_FunAppDiscount = lookup_def_int "-funfolding-fun-discount" (6::Int) -- It's great to inline a fn
797 opt_UF_KeenessFactor = lookup_def_float "-funfolding-keeness-factor" (1.5::Float)
798 opt_UF_UpdateInPlace = lookUp FSLIT("-funfolding-update-in-place")
800 opt_UF_DearOp = ( 4 :: Int)
802 opt_Static = lookUp FSLIT("-static")
803 opt_Unregisterised = lookUp FSLIT("-funregisterised")
804 opt_EmitExternalCore = lookUp FSLIT("-fext-core")
806 -- Include full span info in error messages, instead of just the start position.
807 opt_ErrorSpans = lookUp FSLIT("-ferror-spans")
810 %************************************************************************
812 \subsection{List of static hsc flags}
814 %************************************************************************
819 "fauto-sccs-on-all-toplevs",
820 "fauto-sccs-on-exported-toplevs",
821 "fauto-sccs-on-individual-cafs",
822 "fauto-sccs-on-dicts",
827 "firrefutable-tuples",
833 "femit-extern-decls",
834 "fglobalise-toplev-names",
836 "fno-hi-version-check",
838 "fno-method-sharing",
842 "funfolding-update-in-place",
852 || any (flip prefixMatch f) [
854 "fliberate-case-threshold",
857 "funfolding-creation-threshold",
858 "funfolding-use-threshold",
859 "funfolding-fun-discount",
860 "funfolding-keeness-factor"
864 %************************************************************************
866 \subsection{Misc functions for command-line options}
868 %************************************************************************
873 startsWith :: String -> String -> Maybe String
874 -- startsWith pfx (pfx++rest) = Just rest
876 startsWith [] str = Just str
877 startsWith (c:cs) (s:ss)
878 = if c /= s then Nothing else startsWith cs ss
879 startsWith _ [] = Nothing
881 endsWith :: String -> String -> Maybe String
883 = case (startsWith (reverse cs) (reverse ss)) of
885 Just rs -> Just (reverse rs)