ghc/compiler/main/CmdLineOpts.lhs

   1 %
   2 % (c) The University of Glasgow, 1996-2000
   3 %
   4 \section[CmdLineOpts]{Things to do with command-line options}
   5
   6 \begin{code}
   7
   8 module CmdLineOpts (
   9         CoreToDo(..),
  10         SimplifierSwitch(..), isAmongSimpl,
  11         StgToDo(..),
  12         SwitchResult(..),
  13
  14         HscLang(..),
  15         DynFlag(..),    -- needed non-abstractly by DriverFlags
  16         DynFlags(..),
  17         defaultDynFlags,
  18
  19         v_Static_hsc_opts,
  20
  21         intSwitchSet,
  22         switchIsOn,
  23         isStaticHscFlag,
  24
  25         opt_PprStyle_NoPrags,
  26         opt_PprStyle_RawTypes,
  27         opt_PprUserLength,
  28         opt_PprStyle_Debug,
  29
  30         dopt,
  31
  32         -- other dynamic flags
  33         dopt_CoreToDo,
  34         dopt_StgToDo,
  35         dopt_HscLang,
  36         dopt_OutName,
  37
  38         -- profiling opts
  39         opt_AutoSccsOnAllToplevs,
  40         opt_AutoSccsOnExportedToplevs,
  41         opt_AutoSccsOnIndividualCafs,
  42         opt_AutoSccsOnDicts,
  43         opt_SccProfilingOn,
  44         opt_DoTickyProfiling,
  45
  46         -- language opts
  47         opt_AllStrict,
  48         opt_DictsStrict,
  49         opt_MaxContextReductionDepth,
  50         opt_IrrefutableTuples,
  51         opt_NumbersStrict,
  52         opt_Parallel,
  53         opt_SMP,
  54         opt_NoMonomorphismRestriction,
  55
  56         -- optimisation opts
  57         opt_DoSemiTagging,
  58         opt_FoldrBuildOn,
  59         opt_LiberateCaseThreshold,
  60         opt_StgDoLetNoEscapes,
  61         opt_UnfoldCasms,
  62         opt_UsageSPOn,
  63         opt_UnboxStrictFields,
  64         opt_SimplNoPreInlining,
  65         opt_SimplDoEtaReduction,
  66         opt_SimplDoLambdaEtaExpansion,
  67         opt_SimplCaseOfCase,
  68         opt_SimplCaseMerge,
  69         opt_SimplPedanticBottoms,
  70         opt_SimplExcessPrecision,
  71
  72         -- Unfolding control
  73         opt_UF_HiFileThreshold,
  74         opt_UF_CreationThreshold,
  75         opt_UF_UseThreshold,
  76         opt_UF_FunAppDiscount,
  77         opt_UF_KeenessFactor,
  78         opt_UF_UpdateInPlace,
  79         opt_UF_CheapOp,
  80         opt_UF_DearOp,
  81
  82         -- misc opts
  83         opt_InPackage,
  84         opt_EmitCExternDecls,
  85         opt_EnsureSplittableC,
  86         opt_GranMacros,
  87         opt_HiVersion,
  88         opt_HistorySize,
  89         opt_IgnoreAsserts,
  90         opt_IgnoreIfacePragmas,
  91         opt_NoHiCheck,
  92         opt_OmitBlackHoling,
  93         opt_OmitInterfacePragmas,
  94         opt_NoPruneTyDecls,
  95         opt_NoPruneDecls,
  96         opt_Static,
  97         opt_Unregisterised
  98     ) where
  99
 100 #include "HsVersions.h"
 101
 102 import Array    ( array, (//) )
 103 import GlaExts
 104 import IOExts   ( IORef, readIORef )
 105 import Constants        -- Default values for some flags
 106 import Util
 107 import FastTypes
 108 import Config
 109
 110 import Maybes           ( firstJust )
 111 import Panic            ( panic )
 112
 113 #if __GLASGOW_HASKELL__ < 301
 114 import ArrBase  ( Array(..) )
 115 #else
 116 import PrelArr  ( Array(..) )
 117 #endif
 118 \end{code}
 119
 120 %************************************************************************
 121 %*                                                                      *
 122 \subsection{Command-line options}
 123 %*                                                                      *
 124 %************************************************************************
 125
 126 The hsc command-line options are split into two categories:
 127
 128   - static flags
 129   - dynamic flags
 130
 131 Static flags are represented by top-level values of type Bool or Int,
 132 for example.  They therefore have the same value throughout the
 133 invocation of hsc.
 134
 135 Dynamic flags are represented by an abstract type, DynFlags, which is
 136 passed into hsc by the compilation manager for every compilation.
 137 Dynamic flags are those that change on a per-compilation basis,
 138 perhaps because they may be present in the OPTIONS pragma at the top
 139 of a module.
 140
 141 Other flag-related blurb:
 142
 143 A list of {\em ToDo}s is things to be done in a particular part of
 144 processing.  A (fictitious) example for the Core-to-Core simplifier
 145 might be: run the simplifier, then run the strictness analyser, then
 146 run the simplifier again (three ``todos'').
 147
 148 There are three ``to-do processing centers'' at the moment.  In the
 149 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
 150 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
 151 (\tr{simplStg/SimplStg.lhs}).
 152
 153 %************************************************************************
 154 %*                                                                      *
 155 \subsection{Datatypes associated with command-line options}
 156 %*                                                                      *
 157 %************************************************************************
 158
 159 \begin{code}
 160 data SwitchResult
 161   = SwBool      Bool            -- on/off
 162   | SwString    FAST_STRING     -- nothing or a String
 163   | SwInt       Int             -- nothing or an Int
 164 \end{code}
 165
 166 \begin{code}
 167 data CoreToDo           -- These are diff core-to-core passes,
 168                         -- which may be invoked in any order,
 169                         -- as many times as you like.
 170
 171   = CoreDoSimplify      -- The core-to-core simplifier.
 172         (SimplifierSwitch -> SwitchResult)
 173                         -- Each run of the simplifier can take a different
 174                         -- set of simplifier-specific flags.
 175   | CoreDoFloatInwards
 176   | CoreDoFloatOutwards Bool    -- True <=> float lambdas to top level
 177   | CoreLiberateCase
 178   | CoreDoPrintCore
 179   | CoreDoStaticArgs
 180   | CoreDoStrictness
 181   | CoreDoWorkerWrapper
 182   | CoreDoSpecialising
 183   | CoreDoUSPInf
 184   | CoreDoCPResult
 185   | CoreDoGlomBinds
 186   | CoreCSE
 187
 188   | CoreDoNothing        -- useful when building up lists of these things
 189 \end{code}
 190
 191 \begin{code}
 192 data StgToDo
 193   = StgDoMassageForProfiling  -- should be (next to) last
 194   -- There's also setStgVarInfo, but its absolute "lastness"
 195   -- is so critical that it is hardwired in (no flag).
 196   | D_stg_stats
 197 \end{code}
 198
 199 \begin{code}
 200 data SimplifierSwitch
 201   = MaxSimplifierIterations Int
 202   | SimplInlinePhase Int
 203   | DontApplyRules
 204   | NoCaseOfCase
 205   | SimplLetToCase
 206 \end{code}
 207
 208 %************************************************************************
 209 %*                                                                      *
 210 \subsection{Dynamic command-line options}
 211 %*                                                                      *
 212 %************************************************************************
 213
 214 \begin{code}
 215 data DynFlag
 216
 217    -- debugging flags
 218    = Opt_D_dump_absC
 219    | Opt_D_dump_asm
 220    | Opt_D_dump_cpranal
 221    | Opt_D_dump_deriv
 222    | Opt_D_dump_ds
 223    | Opt_D_dump_flatC
 224    | Opt_D_dump_foreign
 225    | Opt_D_dump_inlinings
 226    | Opt_D_dump_occur_anal
 227    | Opt_D_dump_parsed
 228    | Opt_D_dump_realC
 229    | Opt_D_dump_rn
 230    | Opt_D_dump_simpl
 231    | Opt_D_dump_simpl_iterations
 232    | Opt_D_dump_spec
 233    | Opt_D_dump_sat
 234    | Opt_D_dump_stg
 235    | Opt_D_dump_stranal
 236    | Opt_D_dump_tc
 237    | Opt_D_dump_types
 238    | Opt_D_dump_rules
 239    | Opt_D_dump_usagesp
 240    | Opt_D_dump_cse
 241    | Opt_D_dump_worker_wrapper
 242    | Opt_D_dump_rn_trace
 243    | Opt_D_dump_rn_stats
 244    | Opt_D_dump_stix
 245    | Opt_D_dump_simpl_stats
 246    | Opt_D_dump_BCOs
 247    | Opt_D_source_stats
 248    | Opt_D_verbose_core2core
 249    | Opt_D_verbose_stg2stg
 250    | Opt_D_dump_hi
 251    | Opt_D_dump_hi_diffs
 252    | Opt_D_dump_minimal_imports
 253    | Opt_DoCoreLinting
 254    | Opt_DoStgLinting
 255    | Opt_DoUSPLinting
 256
 257    | Opt_WarnDuplicateExports
 258    | Opt_WarnHiShadows
 259    | Opt_WarnIncompletePatterns
 260    | Opt_WarnMissingFields
 261    | Opt_WarnMissingMethods
 262    | Opt_WarnMissingSigs
 263    | Opt_WarnNameShadowing
 264    | Opt_WarnOverlappingPatterns
 265    | Opt_WarnSimplePatterns
 266    | Opt_WarnTypeDefaults
 267    | Opt_WarnUnusedBinds
 268    | Opt_WarnUnusedImports
 269    | Opt_WarnUnusedMatches
 270    | Opt_WarnDeprecations
 271
 272    -- language opts
 273    | Opt_AllowOverlappingInstances
 274    | Opt_AllowUndecidableInstances
 275    | Opt_GlasgowExts
 276    | Opt_Generics
 277    | Opt_NoImplicitPrelude
 278
 279    -- misc
 280    | Opt_ReportCompile
 281    deriving (Eq)
 282
 283 data DynFlags = DynFlags {
 284   coreToDo   :: [CoreToDo],
 285   stgToDo    :: [StgToDo],
 286   hscLang    :: HscLang,
 287   hscOutName :: String,  -- name of the file in which to place output
 288   verbosity  :: Int,     -- verbosity level
 289   flags      :: [DynFlag]
 290  }
 291
 292 defaultDynFlags = DynFlags {
 293   coreToDo = [], stgToDo = [],
 294   hscLang = HscC, hscOutName = "",
 295   verbosity = 0, flags = []
 296   }
 297
 298 {-
 299     Verbosity levels:
 300
 301     0   |   print errors & warnings only
 302     1   |   minimal verbosity: print "compiling M ... done." for each module.
 303     2   |   equivalent to -dshow-passes
 304     3   |   equivalent to existing "ghc -v"
 305     4   |   "ghc -v -ddump-most"
 306     5   |   "ghc -v -ddump-all"
 307 -}
 308
 309 dopt :: DynFlag -> DynFlags -> Bool
 310 dopt f dflags  = f `elem` (flags dflags)
 311
 312 dopt_CoreToDo :: DynFlags -> [CoreToDo]
 313 dopt_CoreToDo = coreToDo
 314
 315 dopt_StgToDo :: DynFlags -> [StgToDo]
 316 dopt_StgToDo = stgToDo
 317
 318 dopt_OutName :: DynFlags -> String
 319 dopt_OutName = hscOutName
 320
 321 data HscLang
 322   = HscC
 323   | HscAsm
 324   | HscJava
 325   | HscInterpreted
 326     deriving (Eq, Show)
 327
 328 dopt_HscLang :: DynFlags -> HscLang
 329 dopt_HscLang = hscLang
 330 \end{code}
 331
 332 %************************************************************************
 333 %*                                                                      *
 334 \subsection{Classifying command-line options}
 335 %*                                                                      *
 336 %************************************************************************
 337
 338 \begin{code}
 339 -- v_Statis_hsc_opts is here to avoid a circular dependency with
 340 -- main/DriverState.
 341 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
 342
 343 lookUp           :: FAST_STRING -> Bool
 344 lookup_int       :: String -> Maybe Int
 345 lookup_def_int   :: String -> Int -> Int
 346 lookup_def_float :: String -> Float -> Float
 347 lookup_str       :: String -> Maybe String
 348
 349 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
 350 packed_static_opts   = map _PK_ unpacked_static_opts
 351
 352 lookUp     sw = sw `elem` packed_static_opts
 353
 354 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
 355
 356 lookup_int sw = case (lookup_str sw) of
 357                   Nothing -> Nothing
 358                   Just xx -> Just (read xx)
 359
 360 lookup_def_int sw def = case (lookup_str sw) of
 361                             Nothing -> def              -- Use default
 362                             Just xx -> read xx
 363
 364 lookup_def_float sw def = case (lookup_str sw) of
 365                             Nothing -> def              -- Use default
 366                             Just xx -> read xx
 367
 368
 369 {-
 370  Putting the compiler options into temporary at-files
 371  may turn out to be necessary later on if we turn hsc into
 372  a pure Win32 application where I think there's a command-line
 373  length limit of 255. unpacked_opts understands the @ option.
 374
 375 unpacked_opts :: [String]
 376 unpacked_opts =
 377   concat $
 378   map (expandAts) $
 379   map _UNPK_ argv  -- NOT ARGV any more: v_Static_hsc_opts
 380   where
 381    expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
 382    expandAts l = [l]
 383 -}
 384 \end{code}
 385
 386 %************************************************************************
 387 %*                                                                      *
 388 \subsection{Static options}
 389 %*                                                                      *
 390 %************************************************************************
 391
 392 \begin{code}
 393 -- debugging opts
 394 opt_PprStyle_NoPrags            = lookUp  SLIT("-dppr-noprags")
 395 opt_PprStyle_Debug              = lookUp  SLIT("-dppr-debug")
 396 opt_PprStyle_RawTypes           = lookUp  SLIT("-dppr-rawtypes")
 397 opt_PprUserLength               = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
 398
 399 -- profiling opts
 400 opt_AutoSccsOnAllToplevs        = lookUp  SLIT("-fauto-sccs-on-all-toplevs")
 401 opt_AutoSccsOnExportedToplevs   = lookUp  SLIT("-fauto-sccs-on-exported-toplevs")
 402 opt_AutoSccsOnIndividualCafs    = lookUp  SLIT("-fauto-sccs-on-individual-cafs")
 403 opt_AutoSccsOnDicts             = lookUp  SLIT("-fauto-sccs-on-dicts")
 404 opt_SccProfilingOn              = lookUp  SLIT("-fscc-profiling")
 405 opt_DoTickyProfiling            = lookUp  SLIT("-fticky-ticky")
 406
 407 -- language opts
 408 opt_AllStrict                   = lookUp  SLIT("-fall-strict")
 409 opt_NoMonomorphismRestriction   = lookUp  SLIT("-fno-monomorphism-restriction")
 410 opt_DictsStrict                 = lookUp  SLIT("-fdicts-strict")
 411 opt_IrrefutableTuples           = lookUp  SLIT("-firrefutable-tuples")
 412 opt_MaxContextReductionDepth    = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
 413 opt_NumbersStrict               = lookUp  SLIT("-fnumbers-strict")
 414 opt_Parallel                    = lookUp  SLIT("-fparallel")
 415 opt_SMP                         = lookUp  SLIT("-fsmp")
 416
 417 -- optimisation opts
 418 opt_DoSemiTagging               = lookUp  SLIT("-fsemi-tagging")
 419 opt_FoldrBuildOn                = lookUp  SLIT("-ffoldr-build-on")
 420 opt_LiberateCaseThreshold       = lookup_def_int "-fliberate-case-threshold" (10::Int)
 421 opt_StgDoLetNoEscapes           = lookUp  SLIT("-flet-no-escape")
 422 opt_UnfoldCasms                 = lookUp SLIT("-funfold-casms-in-hi-file")
 423 opt_UsageSPOn                   = lookUp  SLIT("-fusagesp-on")
 424 opt_UnboxStrictFields           = lookUp  SLIT("-funbox-strict-fields")
 425
 426 {-
 427    The optional '-inpackage=P' flag tells what package
 428    we are compiling this module for.
 429    The Prelude, for example is compiled with '-package prelude'
 430 -}
 431 opt_InPackage                   = case lookup_str "-inpackage=" of
 432                                     Just p  -> _PK_ p
 433                                     Nothing -> SLIT("Main")     -- The package name if none is specified
 434
 435 opt_EmitCExternDecls            = lookUp  SLIT("-femit-extern-decls")
 436 opt_EnsureSplittableC           = lookUp  SLIT("-fglobalise-toplev-names")
 437 opt_GranMacros                  = lookUp  SLIT("-fgransim")
 438 opt_HiVersion                   = read cProjectVersionInt :: Int
 439 opt_HistorySize                 = lookup_def_int "-fhistory-size" 20
 440 opt_IgnoreAsserts               = lookUp  SLIT("-fignore-asserts")
 441 opt_IgnoreIfacePragmas          = lookUp  SLIT("-fignore-interface-pragmas")
 442 opt_NoHiCheck                   = lookUp  SLIT("-fno-hi-version-check")
 443 opt_OmitBlackHoling             = lookUp  SLIT("-dno-black-holing")
 444 opt_OmitInterfacePragmas        = lookUp  SLIT("-fomit-interface-pragmas")
 445
 446 -- Simplifier switches
 447 opt_SimplNoPreInlining          = lookUp SLIT("-fno-pre-inlining")
 448         -- NoPreInlining is there just to see how bad things
 449         -- get if you don't do it!
 450 opt_SimplDoEtaReduction         = lookUp SLIT("-fdo-eta-reduction")
 451 opt_SimplDoLambdaEtaExpansion   = lookUp SLIT("-fdo-lambda-eta-expansion")
 452 opt_SimplCaseOfCase             = lookUp SLIT("-fcase-of-case")
 453 opt_SimplCaseMerge              = lookUp SLIT("-fcase-merge")
 454 opt_SimplPedanticBottoms        = lookUp SLIT("-fpedantic-bottoms")
 455 opt_SimplExcessPrecision        = lookUp SLIT("-fexcess-precision")
 456
 457 -- Unfolding control
 458 opt_UF_HiFileThreshold          = lookup_def_int "-funfolding-interface-threshold" (45::Int)
 459 opt_UF_CreationThreshold        = lookup_def_int "-funfolding-creation-threshold"  (45::Int)
 460 opt_UF_UseThreshold             = lookup_def_int "-funfolding-use-threshold"       (8::Int)     -- Discounts can be big
 461 opt_UF_FunAppDiscount           = lookup_def_int "-funfolding-fun-discount"        (6::Int)     -- It's great to inline a fn
 462 opt_UF_KeenessFactor            = lookup_def_float "-funfolding-keeness-factor"    (1.5::Float)
 463 opt_UF_UpdateInPlace            = lookUp  SLIT("-funfolding-update-in-place")
 464
 465 opt_UF_CheapOp  = ( 1 :: Int)   -- Only one instruction; and the args are charged for
 466 opt_UF_DearOp   = ( 4 :: Int)
 467
 468 opt_NoPruneDecls                = lookUp SLIT("-fno-prune-decls")
 469 opt_NoPruneTyDecls              = lookUp SLIT("-fno-prune-tydecls")
 470 opt_Static                      = lookUp SLIT("-static")
 471 opt_Unregisterised              = lookUp SLIT("-funregisterised")
 472 \end{code}
 473
 474 %************************************************************************
 475 %*                                                                      *
 476 \subsection{List of static hsc flags}
 477 %*                                                                      *
 478 %************************************************************************
 479
 480 \begin{code}
 481 isStaticHscFlag f =
 482   f `elem` [
 483         "fauto-sccs-on-all-toplevs",
 484         "fauto-sccs-on-exported-toplevs",
 485         "fauto-sccs-on-individual-cafs",
 486         "fauto-sccs-on-dicts",
 487         "fscc-profiling",
 488         "fticky-ticky",
 489         "fall-strict",
 490         "fdicts-strict",
 491         "firrefutable-tuples",
 492         "fnumbers-strict",
 493         "fparallel",
 494         "fsmp",
 495         "fsemi-tagging",
 496         "ffoldr-build-on",
 497         "flet-no-escape",
 498         "funfold-casms-in-hi-file",
 499         "fusagesp-on",
 500         "funbox-strict-fields",
 501         "femit-extern-decls",
 502         "fglobalise-toplev-names",
 503         "fgransim",
 504         "fignore-asserts",
 505         "fignore-interface-pragmas",
 506         "fno-hi-version-check",
 507         "dno-black-holing",
 508         "fomit-interface-pragmas",
 509         "fno-pre-inlining",
 510         "fdo-eta-reduction",
 511         "fdo-lambda-eta-expansion",
 512         "fcase-of-case",
 513         "fcase-merge",
 514         "fpedantic-bottoms",
 515         "fexcess-precision",
 516         "funfolding-update-in-place",
 517         "freport-compile",
 518         "fno-prune-decls",
 519         "fno-prune-tydecls",
 520         "static",
 521         "funregisterised"
 522         ]
 523   || any (flip prefixMatch f) [
 524         "fcontext-stack",
 525         "fliberate-case-threshold",
 526         "fhistory-size",
 527         "funfolding-interface-threshold",
 528         "funfolding-creation-threshold",
 529         "funfolding-use-threshold",
 530         "funfolding-fun-discount",
 531         "funfolding-keeness-factor"
 532      ]
 533 \end{code}
 534
 535 %************************************************************************
 536 %*                                                                      *
 537 \subsection{Switch ordering}
 538 %*                                                                      *
 539 %************************************************************************
 540
 541 These things behave just like enumeration types.
 542
 543 \begin{code}
 544 instance Eq SimplifierSwitch where
 545     a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b
 546
 547 instance Ord SimplifierSwitch where
 548     a <  b  = tagOf_SimplSwitch a <# tagOf_SimplSwitch b
 549     a <= b  = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b
 550
 551
 552 tagOf_SimplSwitch (SimplInlinePhase _)          = _ILIT(1)
 553 tagOf_SimplSwitch (MaxSimplifierIterations _)   = _ILIT(2)
 554 tagOf_SimplSwitch DontApplyRules                = _ILIT(3)
 555 tagOf_SimplSwitch SimplLetToCase                = _ILIT(4)
 556 tagOf_SimplSwitch NoCaseOfCase                  = _ILIT(5)
 557
 558 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 559
 560 lAST_SIMPL_SWITCH_TAG = 5
 561 \end{code}
 562
 563 %************************************************************************
 564 %*                                                                      *
 565 \subsection{Switch lookup}
 566 %*                                                                      *
 567 %************************************************************************
 568
 569 \begin{code}
 570 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 571 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 572                                         -- in the list; defaults right at the end.
 573   = let
 574         tidied_on_switches = foldl rm_dups [] on_switches
 575                 -- The fold*l* ensures that we keep the latest switches;
 576                 -- ie the ones that occur earliest in the list.
 577
 578         sw_tbl :: Array Int SwitchResult
 579         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 580                         all_undefined)
 581                  // defined_elems
 582
 583         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 584
 585         defined_elems = map mk_assoc_elem tidied_on_switches
 586     in
 587     -- (avoid some unboxing, bounds checking, and other horrible things:)
 588 #if __GLASGOW_HASKELL__ < 405
 589     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 590 #else
 591     case sw_tbl of { Array _ _ stuff ->
 592 #endif
 593     \ switch ->
 594         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 595 #if __GLASGOW_HASKELL__ < 400
 596           Lift v -> v
 597 #elif __GLASGOW_HASKELL__ < 403
 598           (# _, v #) -> v
 599 #else
 600           (# v #) -> v
 601 #endif
 602     }
 603   where
 604     mk_assoc_elem k@(MaxSimplifierIterations lvl)
 605         = (iBox (tagOf_SimplSwitch k), SwInt lvl)
 606     mk_assoc_elem k@(SimplInlinePhase n)
 607         = (iBox (tagOf_SimplSwitch k), SwInt n)
 608     mk_assoc_elem k
 609         = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 610
 611     -- cannot have duplicates if we are going to use the array thing
 612     rm_dups switches_so_far switch
 613       = if switch `is_elem` switches_so_far
 614         then switches_so_far
 615         else switch : switches_so_far
 616       where
 617         sw `is_elem` []     = False
 618         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s)
 619                             || sw `is_elem` ss
 620 \end{code}
 621
 622
 623 %************************************************************************
 624 %*                                                                      *
 625 \subsection{Misc functions for command-line options}
 626 %*                                                                      *
 627 %************************************************************************
 628
 629
 630 \begin{code}
 631 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 632
 633 switchIsOn lookup_fn switch
 634   = case (lookup_fn switch) of
 635       SwBool False -> False
 636       _            -> True
 637
 638 intSwitchSet :: (switch -> SwitchResult)
 639              -> (Int -> switch)
 640              -> Maybe Int
 641
 642 intSwitchSet lookup_fn switch
 643   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 644       SwInt int -> Just int
 645       _         -> Nothing
 646 \end{code}
 647
 648 \begin{code}
 649 startsWith :: String -> String -> Maybe String
 650 -- startsWith pfx (pfx++rest) = Just rest
 651
 652 startsWith []     str = Just str
 653 startsWith (c:cs) (s:ss)
 654   = if c /= s then Nothing else startsWith cs ss
 655 startsWith  _     []  = Nothing
 656
 657 endsWith  :: String -> String -> Maybe String
 658 endsWith cs ss
 659   = case (startsWith (reverse cs) (reverse ss)) of
 660       Nothing -> Nothing
 661       Just rs -> Just (reverse rs)
 662 \end{code}