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 output file
 288   verbosity             :: Int,         -- verbosity level
 289   cppFlag               :: Bool,        -- preprocess with cpp?
 290   stolen_x86_regs       :: Int,
 291   cmdlineHcIncludes     :: [String],    -- -#includes
 292
 293   -- options for particular phases
 294   opt_L                 :: [String],
 295   opt_P                 :: [String],
 296   opt_c                 :: [String],
 297   opt_a                 :: [String],
 298   opt_m                 :: [String],
 299
 300   -- hsc dynamic flags
 301   flags                 :: [DynFlag]
 302  }
 303
 304 defaultDynFlags = DynFlags {
 305   coreToDo = [], stgToDo = [],
 306   hscLang = HscC,
 307   hscOutName = "",
 308   verbosity = 0,
 309   cppFlag               = False,
 310   stolen_x86_regs       = 4,
 311   cmdlineHcIncludes     = [],
 312   opt_L                 = [],
 313   opt_P                 = [],
 314   opt_c                 = [],
 315   opt_a                 = [],
 316   opt_m                 = [],
 317   flags = []
 318   }
 319
 320 {-
 321     Verbosity levels:
 322
 323     0   |   print errors & warnings only
 324     1   |   minimal verbosity: print "compiling M ... done." for each module.
 325     2   |   equivalent to -dshow-passes
 326     3   |   equivalent to existing "ghc -v"
 327     4   |   "ghc -v -ddump-most"
 328     5   |   "ghc -v -ddump-all"
 329 -}
 330
 331 dopt :: DynFlag -> DynFlags -> Bool
 332 dopt f dflags  = f `elem` (flags dflags)
 333
 334 dopt_CoreToDo :: DynFlags -> [CoreToDo]
 335 dopt_CoreToDo = coreToDo
 336
 337 dopt_StgToDo :: DynFlags -> [StgToDo]
 338 dopt_StgToDo = stgToDo
 339
 340 dopt_OutName :: DynFlags -> String
 341 dopt_OutName = hscOutName
 342
 343 data HscLang
 344   = HscC
 345   | HscAsm
 346   | HscJava
 347   | HscInterpreted
 348     deriving (Eq, Show)
 349
 350 dopt_HscLang :: DynFlags -> HscLang
 351 dopt_HscLang = hscLang
 352 \end{code}
 353
 354 %************************************************************************
 355 %*                                                                      *
 356 \subsection{Classifying command-line options}
 357 %*                                                                      *
 358 %************************************************************************
 359
 360 \begin{code}
 361 -- v_Statis_hsc_opts is here to avoid a circular dependency with
 362 -- main/DriverState.
 363 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
 364
 365 lookUp           :: FAST_STRING -> Bool
 366 lookup_int       :: String -> Maybe Int
 367 lookup_def_int   :: String -> Int -> Int
 368 lookup_def_float :: String -> Float -> Float
 369 lookup_str       :: String -> Maybe String
 370
 371 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
 372 packed_static_opts   = map _PK_ unpacked_static_opts
 373
 374 lookUp     sw = sw `elem` packed_static_opts
 375
 376 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
 377
 378 lookup_int sw = case (lookup_str sw) of
 379                   Nothing -> Nothing
 380                   Just xx -> Just (read xx)
 381
 382 lookup_def_int sw def = case (lookup_str sw) of
 383                             Nothing -> def              -- Use default
 384                             Just xx -> read xx
 385
 386 lookup_def_float sw def = case (lookup_str sw) of
 387                             Nothing -> def              -- Use default
 388                             Just xx -> read xx
 389
 390
 391 {-
 392  Putting the compiler options into temporary at-files
 393  may turn out to be necessary later on if we turn hsc into
 394  a pure Win32 application where I think there's a command-line
 395  length limit of 255. unpacked_opts understands the @ option.
 396
 397 unpacked_opts :: [String]
 398 unpacked_opts =
 399   concat $
 400   map (expandAts) $
 401   map _UNPK_ argv  -- NOT ARGV any more: v_Static_hsc_opts
 402   where
 403    expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
 404    expandAts l = [l]
 405 -}
 406 \end{code}
 407
 408 %************************************************************************
 409 %*                                                                      *
 410 \subsection{Static options}
 411 %*                                                                      *
 412 %************************************************************************
 413
 414 \begin{code}
 415 -- debugging opts
 416 opt_PprStyle_NoPrags            = lookUp  SLIT("-dppr-noprags")
 417 opt_PprStyle_Debug              = lookUp  SLIT("-dppr-debug")
 418 opt_PprStyle_RawTypes           = lookUp  SLIT("-dppr-rawtypes")
 419 opt_PprUserLength               = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
 420
 421 -- profiling opts
 422 opt_AutoSccsOnAllToplevs        = lookUp  SLIT("-fauto-sccs-on-all-toplevs")
 423 opt_AutoSccsOnExportedToplevs   = lookUp  SLIT("-fauto-sccs-on-exported-toplevs")
 424 opt_AutoSccsOnIndividualCafs    = lookUp  SLIT("-fauto-sccs-on-individual-cafs")
 425 opt_AutoSccsOnDicts             = lookUp  SLIT("-fauto-sccs-on-dicts")
 426 opt_SccProfilingOn              = lookUp  SLIT("-fscc-profiling")
 427 opt_DoTickyProfiling            = lookUp  SLIT("-fticky-ticky")
 428
 429 -- language opts
 430 opt_AllStrict                   = lookUp  SLIT("-fall-strict")
 431 opt_NoMonomorphismRestriction   = lookUp  SLIT("-fno-monomorphism-restriction")
 432 opt_DictsStrict                 = lookUp  SLIT("-fdicts-strict")
 433 opt_IrrefutableTuples           = lookUp  SLIT("-firrefutable-tuples")
 434 opt_MaxContextReductionDepth    = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
 435 opt_NumbersStrict               = lookUp  SLIT("-fnumbers-strict")
 436 opt_Parallel                    = lookUp  SLIT("-fparallel")
 437 opt_SMP                         = lookUp  SLIT("-fsmp")
 438
 439 -- optimisation opts
 440 opt_DoSemiTagging               = lookUp  SLIT("-fsemi-tagging")
 441 opt_FoldrBuildOn                = lookUp  SLIT("-ffoldr-build-on")
 442 opt_LiberateCaseThreshold       = lookup_def_int "-fliberate-case-threshold" (10::Int)
 443 opt_StgDoLetNoEscapes           = lookUp  SLIT("-flet-no-escape")
 444 opt_UnfoldCasms                 = lookUp SLIT("-funfold-casms-in-hi-file")
 445 opt_UsageSPOn                   = lookUp  SLIT("-fusagesp-on")
 446 opt_UnboxStrictFields           = lookUp  SLIT("-funbox-strict-fields")
 447
 448 {-
 449    The optional '-inpackage=P' flag tells what package
 450    we are compiling this module for.
 451    The Prelude, for example is compiled with '-package prelude'
 452 -}
 453 opt_InPackage                   = case lookup_str "-inpackage=" of
 454                                     Just p  -> _PK_ p
 455                                     Nothing -> SLIT("Main")     -- The package name if none is specified
 456
 457 opt_EmitCExternDecls            = lookUp  SLIT("-femit-extern-decls")
 458 opt_EnsureSplittableC           = lookUp  SLIT("-fglobalise-toplev-names")
 459 opt_GranMacros                  = lookUp  SLIT("-fgransim")
 460 opt_HiVersion                   = read cProjectVersionInt :: Int
 461 opt_HistorySize                 = lookup_def_int "-fhistory-size" 20
 462 opt_IgnoreAsserts               = lookUp  SLIT("-fignore-asserts")
 463 opt_IgnoreIfacePragmas          = lookUp  SLIT("-fignore-interface-pragmas")
 464 opt_NoHiCheck                   = lookUp  SLIT("-fno-hi-version-check")
 465 opt_OmitBlackHoling             = lookUp  SLIT("-dno-black-holing")
 466 opt_OmitInterfacePragmas        = lookUp  SLIT("-fomit-interface-pragmas")
 467
 468 -- Simplifier switches
 469 opt_SimplNoPreInlining          = lookUp SLIT("-fno-pre-inlining")
 470         -- NoPreInlining is there just to see how bad things
 471         -- get if you don't do it!
 472 opt_SimplDoEtaReduction         = lookUp SLIT("-fdo-eta-reduction")
 473 opt_SimplDoLambdaEtaExpansion   = lookUp SLIT("-fdo-lambda-eta-expansion")
 474 opt_SimplCaseOfCase             = lookUp SLIT("-fcase-of-case")
 475 opt_SimplCaseMerge              = lookUp SLIT("-fcase-merge")
 476 opt_SimplPedanticBottoms        = lookUp SLIT("-fpedantic-bottoms")
 477 opt_SimplExcessPrecision        = lookUp SLIT("-fexcess-precision")
 478
 479 -- Unfolding control
 480 opt_UF_HiFileThreshold          = lookup_def_int "-funfolding-interface-threshold" (45::Int)
 481 opt_UF_CreationThreshold        = lookup_def_int "-funfolding-creation-threshold"  (45::Int)
 482 opt_UF_UseThreshold             = lookup_def_int "-funfolding-use-threshold"       (8::Int)     -- Discounts can be big
 483 opt_UF_FunAppDiscount           = lookup_def_int "-funfolding-fun-discount"        (6::Int)     -- It's great to inline a fn
 484 opt_UF_KeenessFactor            = lookup_def_float "-funfolding-keeness-factor"    (1.5::Float)
 485 opt_UF_UpdateInPlace            = lookUp  SLIT("-funfolding-update-in-place")
 486
 487 opt_UF_CheapOp  = ( 1 :: Int)   -- Only one instruction; and the args are charged for
 488 opt_UF_DearOp   = ( 4 :: Int)
 489
 490 opt_NoPruneDecls                = lookUp SLIT("-fno-prune-decls")
 491 opt_NoPruneTyDecls              = lookUp SLIT("-fno-prune-tydecls")
 492 opt_Static                      = lookUp SLIT("-static")
 493 opt_Unregisterised              = lookUp SLIT("-funregisterised")
 494 \end{code}
 495
 496 %************************************************************************
 497 %*                                                                      *
 498 \subsection{List of static hsc flags}
 499 %*                                                                      *
 500 %************************************************************************
 501
 502 \begin{code}
 503 isStaticHscFlag f =
 504   f `elem` [
 505         "fauto-sccs-on-all-toplevs",
 506         "fauto-sccs-on-exported-toplevs",
 507         "fauto-sccs-on-individual-cafs",
 508         "fauto-sccs-on-dicts",
 509         "fscc-profiling",
 510         "fticky-ticky",
 511         "fall-strict",
 512         "fdicts-strict",
 513         "firrefutable-tuples",
 514         "fnumbers-strict",
 515         "fparallel",
 516         "fsmp",
 517         "fsemi-tagging",
 518         "ffoldr-build-on",
 519         "flet-no-escape",
 520         "funfold-casms-in-hi-file",
 521         "fusagesp-on",
 522         "funbox-strict-fields",
 523         "femit-extern-decls",
 524         "fglobalise-toplev-names",
 525         "fgransim",
 526         "fignore-asserts",
 527         "fignore-interface-pragmas",
 528         "fno-hi-version-check",
 529         "dno-black-holing",
 530         "fomit-interface-pragmas",
 531         "fno-pre-inlining",
 532         "fdo-eta-reduction",
 533         "fdo-lambda-eta-expansion",
 534         "fcase-of-case",
 535         "fcase-merge",
 536         "fpedantic-bottoms",
 537         "fexcess-precision",
 538         "funfolding-update-in-place",
 539         "freport-compile",
 540         "fno-prune-decls",
 541         "fno-prune-tydecls",
 542         "static",
 543         "funregisterised"
 544         ]
 545   || any (flip prefixMatch f) [
 546         "fcontext-stack",
 547         "fliberate-case-threshold",
 548         "fhistory-size",
 549         "funfolding-interface-threshold",
 550         "funfolding-creation-threshold",
 551         "funfolding-use-threshold",
 552         "funfolding-fun-discount",
 553         "funfolding-keeness-factor"
 554      ]
 555 \end{code}
 556
 557 %************************************************************************
 558 %*                                                                      *
 559 \subsection{Switch ordering}
 560 %*                                                                      *
 561 %************************************************************************
 562
 563 These things behave just like enumeration types.
 564
 565 \begin{code}
 566 instance Eq SimplifierSwitch where
 567     a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b
 568
 569 instance Ord SimplifierSwitch where
 570     a <  b  = tagOf_SimplSwitch a <# tagOf_SimplSwitch b
 571     a <= b  = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b
 572
 573
 574 tagOf_SimplSwitch (SimplInlinePhase _)          = _ILIT(1)
 575 tagOf_SimplSwitch (MaxSimplifierIterations _)   = _ILIT(2)
 576 tagOf_SimplSwitch DontApplyRules                = _ILIT(3)
 577 tagOf_SimplSwitch SimplLetToCase                = _ILIT(4)
 578 tagOf_SimplSwitch NoCaseOfCase                  = _ILIT(5)
 579
 580 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 581
 582 lAST_SIMPL_SWITCH_TAG = 5
 583 \end{code}
 584
 585 %************************************************************************
 586 %*                                                                      *
 587 \subsection{Switch lookup}
 588 %*                                                                      *
 589 %************************************************************************
 590
 591 \begin{code}
 592 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 593 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 594                                         -- in the list; defaults right at the end.
 595   = let
 596         tidied_on_switches = foldl rm_dups [] on_switches
 597                 -- The fold*l* ensures that we keep the latest switches;
 598                 -- ie the ones that occur earliest in the list.
 599
 600         sw_tbl :: Array Int SwitchResult
 601         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 602                         all_undefined)
 603                  // defined_elems
 604
 605         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 606
 607         defined_elems = map mk_assoc_elem tidied_on_switches
 608     in
 609     -- (avoid some unboxing, bounds checking, and other horrible things:)
 610 #if __GLASGOW_HASKELL__ < 405
 611     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 612 #else
 613     case sw_tbl of { Array _ _ stuff ->
 614 #endif
 615     \ switch ->
 616         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 617 #if __GLASGOW_HASKELL__ < 400
 618           Lift v -> v
 619 #elif __GLASGOW_HASKELL__ < 403
 620           (# _, v #) -> v
 621 #else
 622           (# v #) -> v
 623 #endif
 624     }
 625   where
 626     mk_assoc_elem k@(MaxSimplifierIterations lvl)
 627         = (iBox (tagOf_SimplSwitch k), SwInt lvl)
 628     mk_assoc_elem k@(SimplInlinePhase n)
 629         = (iBox (tagOf_SimplSwitch k), SwInt n)
 630     mk_assoc_elem k
 631         = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 632
 633     -- cannot have duplicates if we are going to use the array thing
 634     rm_dups switches_so_far switch
 635       = if switch `is_elem` switches_so_far
 636         then switches_so_far
 637         else switch : switches_so_far
 638       where
 639         sw `is_elem` []     = False
 640         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s)
 641                             || sw `is_elem` ss
 642 \end{code}
 643
 644
 645 %************************************************************************
 646 %*                                                                      *
 647 \subsection{Misc functions for command-line options}
 648 %*                                                                      *
 649 %************************************************************************
 650
 651
 652 \begin{code}
 653 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 654
 655 switchIsOn lookup_fn switch
 656   = case (lookup_fn switch) of
 657       SwBool False -> False
 658       _            -> True
 659
 660 intSwitchSet :: (switch -> SwitchResult)
 661              -> (Int -> switch)
 662              -> Maybe Int
 663
 664 intSwitchSet lookup_fn switch
 665   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 666       SwInt int -> Just int
 667       _         -> Nothing
 668 \end{code}
 669
 670 \begin{code}
 671 startsWith :: String -> String -> Maybe String
 672 -- startsWith pfx (pfx++rest) = Just rest
 673
 674 startsWith []     str = Just str
 675 startsWith (c:cs) (s:ss)
 676   = if c /= s then Nothing else startsWith cs ss
 677 startsWith  _     []  = Nothing
 678
 679 endsWith  :: String -> String -> Maybe String
 680 endsWith cs ss
 681   = case (startsWith (reverse cs) (reverse ss)) of
 682       Nothing -> Nothing
 683       Just rs -> Just (reverse rs)
 684 \end{code}