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         -- sets of warning opts
  39         standardWarnings,
  40         minusWOpts,
  41         minusWallOpts,
  42
  43         -- profiling opts
  44         opt_AutoSccsOnAllToplevs,
  45         opt_AutoSccsOnExportedToplevs,
  46         opt_AutoSccsOnIndividualCafs,
  47         opt_AutoSccsOnDicts,
  48         opt_SccProfilingOn,
  49         opt_DoTickyProfiling,
  50
  51         -- language opts
  52         opt_AllStrict,
  53         opt_DictsStrict,
  54         opt_MaxContextReductionDepth,
  55         opt_IrrefutableTuples,
  56         opt_NumbersStrict,
  57         opt_Parallel,
  58         opt_SMP,
  59         opt_NoMonomorphismRestriction,
  60         opt_KeepStgTypes,
  61
  62         -- optimisation opts
  63         opt_NoMethodSharing,
  64         opt_DoSemiTagging,
  65         opt_FoldrBuildOn,
  66         opt_LiberateCaseThreshold,
  67         opt_StgDoLetNoEscapes,
  68         opt_UnfoldCasms,
  69         opt_UsageSPOn,
  70         opt_UnboxStrictFields,
  71         opt_SimplNoPreInlining,
  72         opt_SimplDoEtaReduction,
  73         opt_SimplDoLambdaEtaExpansion,
  74         opt_SimplCaseMerge,
  75         opt_SimplExcessPrecision,
  76
  77         -- Unfolding control
  78         opt_UF_HiFileThreshold,
  79         opt_UF_CreationThreshold,
  80         opt_UF_UseThreshold,
  81         opt_UF_FunAppDiscount,
  82         opt_UF_KeenessFactor,
  83         opt_UF_UpdateInPlace,
  84         opt_UF_CheapOp,
  85         opt_UF_DearOp,
  86
  87         -- misc opts
  88         opt_InPackage,
  89         opt_EmitCExternDecls,
  90         opt_EnsureSplittableC,
  91         opt_GranMacros,
  92         opt_HiVersion,
  93         opt_HistorySize,
  94         opt_IgnoreAsserts,
  95         opt_IgnoreIfacePragmas,
  96         opt_NoHiCheck,
  97         opt_OmitBlackHoling,
  98         opt_OmitInterfacePragmas,
  99         opt_NoPruneTyDecls,
 100         opt_NoPruneDecls,
 101         opt_Static,
 102         opt_Unregisterised
 103     ) where
 104
 105 #include "HsVersions.h"
 106
 107 import Array    ( array, (//) )
 108 import GlaExts
 109 import IOExts   ( IORef, readIORef )
 110 import Constants        -- Default values for some flags
 111 import Util
 112 import FastTypes
 113 import Config
 114
 115 import Maybes           ( firstJust )
 116 import Panic            ( panic )
 117
 118 #if __GLASGOW_HASKELL__ < 301
 119 import ArrBase  ( Array(..) )
 120 #else
 121 import PrelArr  ( Array(..) )
 122 #endif
 123 \end{code}
 124
 125 %************************************************************************
 126 %*                                                                      *
 127 \subsection{Command-line options}
 128 %*                                                                      *
 129 %************************************************************************
 130
 131 The hsc command-line options are split into two categories:
 132
 133   - static flags
 134   - dynamic flags
 135
 136 Static flags are represented by top-level values of type Bool or Int,
 137 for example.  They therefore have the same value throughout the
 138 invocation of hsc.
 139
 140 Dynamic flags are represented by an abstract type, DynFlags, which is
 141 passed into hsc by the compilation manager for every compilation.
 142 Dynamic flags are those that change on a per-compilation basis,
 143 perhaps because they may be present in the OPTIONS pragma at the top
 144 of a module.
 145
 146 Other flag-related blurb:
 147
 148 A list of {\em ToDo}s is things to be done in a particular part of
 149 processing.  A (fictitious) example for the Core-to-Core simplifier
 150 might be: run the simplifier, then run the strictness analyser, then
 151 run the simplifier again (three ``todos'').
 152
 153 There are three ``to-do processing centers'' at the moment.  In the
 154 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
 155 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
 156 (\tr{simplStg/SimplStg.lhs}).
 157
 158 %************************************************************************
 159 %*                                                                      *
 160 \subsection{Datatypes associated with command-line options}
 161 %*                                                                      *
 162 %************************************************************************
 163
 164 \begin{code}
 165 data SwitchResult
 166   = SwBool      Bool            -- on/off
 167   | SwString    FAST_STRING     -- nothing or a String
 168   | SwInt       Int             -- nothing or an Int
 169 \end{code}
 170
 171 \begin{code}
 172 data CoreToDo           -- These are diff core-to-core passes,
 173                         -- which may be invoked in any order,
 174                         -- as many times as you like.
 175
 176   = CoreDoSimplify      -- The core-to-core simplifier.
 177         (SimplifierSwitch -> SwitchResult)
 178                         -- Each run of the simplifier can take a different
 179                         -- set of simplifier-specific flags.
 180   | CoreDoFloatInwards
 181   | CoreDoFloatOutwards Bool    -- True <=> float lambdas to top level
 182   | CoreLiberateCase
 183   | CoreDoPrintCore
 184   | CoreDoStaticArgs
 185   | CoreDoStrictness
 186   | CoreDoWorkerWrapper
 187   | CoreDoSpecialising
 188   | CoreDoUSPInf
 189   | CoreDoCPResult
 190   | CoreDoGlomBinds
 191   | CoreCSE
 192
 193   | CoreDoNothing        -- useful when building up lists of these things
 194 \end{code}
 195
 196 \begin{code}
 197 data StgToDo
 198   = StgDoMassageForProfiling  -- should be (next to) last
 199   -- There's also setStgVarInfo, but its absolute "lastness"
 200   -- is so critical that it is hardwired in (no flag).
 201   | D_stg_stats
 202 \end{code}
 203
 204 \begin{code}
 205 data SimplifierSwitch
 206   = MaxSimplifierIterations Int
 207   | SimplInlinePhase Int
 208   | DontApplyRules
 209   | NoCaseOfCase
 210   | SimplLetToCase
 211 \end{code}
 212
 213 %************************************************************************
 214 %*                                                                      *
 215 \subsection{Dynamic command-line options}
 216 %*                                                                      *
 217 %************************************************************************
 218
 219 \begin{code}
 220 data DynFlag
 221
 222    -- debugging flags
 223    = Opt_D_dump_absC
 224    | Opt_D_dump_asm
 225    | Opt_D_dump_cpranal
 226    | Opt_D_dump_deriv
 227    | Opt_D_dump_ds
 228    | Opt_D_dump_flatC
 229    | Opt_D_dump_foreign
 230    | Opt_D_dump_inlinings
 231    | Opt_D_dump_occur_anal
 232    | Opt_D_dump_parsed
 233    | Opt_D_dump_realC
 234    | Opt_D_dump_rn
 235    | Opt_D_dump_simpl
 236    | Opt_D_dump_simpl_iterations
 237    | Opt_D_dump_spec
 238    | Opt_D_dump_sat
 239    | Opt_D_dump_stg
 240    | Opt_D_dump_stranal
 241    | Opt_D_dump_tc
 242    | Opt_D_dump_types
 243    | Opt_D_dump_rules
 244    | Opt_D_dump_usagesp
 245    | Opt_D_dump_cse
 246    | Opt_D_dump_worker_wrapper
 247    | Opt_D_dump_rn_trace
 248    | Opt_D_dump_rn_stats
 249    | Opt_D_dump_stix
 250    | Opt_D_dump_simpl_stats
 251    | Opt_D_dump_tc_trace
 252    | Opt_D_dump_BCOs
 253    | Opt_D_source_stats
 254    | Opt_D_verbose_core2core
 255    | Opt_D_verbose_stg2stg
 256    | Opt_D_dump_hi
 257    | Opt_D_dump_hi_diffs
 258    | Opt_D_dump_minimal_imports
 259    | Opt_DoCoreLinting
 260    | Opt_DoStgLinting
 261    | Opt_DoUSPLinting
 262
 263    | Opt_WarnDuplicateExports
 264    | Opt_WarnHiShadows
 265    | Opt_WarnIncompletePatterns
 266    | Opt_WarnMissingFields
 267    | Opt_WarnMissingMethods
 268    | Opt_WarnMissingSigs
 269    | Opt_WarnNameShadowing
 270    | Opt_WarnOverlappingPatterns
 271    | Opt_WarnSimplePatterns
 272    | Opt_WarnTypeDefaults
 273    | Opt_WarnUnusedBinds
 274    | Opt_WarnUnusedImports
 275    | Opt_WarnUnusedMatches
 276    | Opt_WarnDeprecations
 277
 278    -- language opts
 279    | Opt_AllowOverlappingInstances
 280    | Opt_AllowUndecidableInstances
 281    | Opt_GlasgowExts
 282    | Opt_Generics
 283    | Opt_NoImplicitPrelude
 284
 285    deriving (Eq)
 286
 287 data DynFlags = DynFlags {
 288   coreToDo              :: [CoreToDo],
 289   stgToDo               :: [StgToDo],
 290   hscLang               :: HscLang,
 291   hscOutName            :: String,      -- name of the output file
 292   verbosity             :: Int,         -- verbosity level
 293   cppFlag               :: Bool,        -- preprocess with cpp?
 294   stolen_x86_regs       :: Int,
 295   cmdlineHcIncludes     :: [String],    -- -#includes
 296
 297   -- options for particular phases
 298   opt_L                 :: [String],
 299   opt_P                 :: [String],
 300   opt_c                 :: [String],
 301   opt_a                 :: [String],
 302   opt_m                 :: [String],
 303
 304   -- hsc dynamic flags
 305   flags                 :: [DynFlag]
 306  }
 307
 308 defaultDynFlags = DynFlags {
 309   coreToDo = [], stgToDo = [],
 310   hscLang = HscC,
 311   hscOutName = "",
 312   verbosity = 0,
 313   cppFlag               = False,
 314   stolen_x86_regs       = 4,
 315   cmdlineHcIncludes     = [],
 316   opt_L                 = [],
 317   opt_P                 = [],
 318   opt_c                 = [],
 319   opt_a                 = [],
 320   opt_m                 = [],
 321   flags = standardWarnings,
 322   }
 323
 324 {-
 325     Verbosity levels:
 326
 327     0   |   print errors & warnings only
 328     1   |   minimal verbosity: print "compiling M ... done." for each module.
 329     2   |   equivalent to -dshow-passes
 330     3   |   equivalent to existing "ghc -v"
 331     4   |   "ghc -v -ddump-most"
 332     5   |   "ghc -v -ddump-all"
 333 -}
 334
 335 dopt :: DynFlag -> DynFlags -> Bool
 336 dopt f dflags  = f `elem` (flags dflags)
 337
 338 dopt_CoreToDo :: DynFlags -> [CoreToDo]
 339 dopt_CoreToDo = coreToDo
 340
 341 dopt_StgToDo :: DynFlags -> [StgToDo]
 342 dopt_StgToDo = stgToDo
 343
 344 dopt_OutName :: DynFlags -> String
 345 dopt_OutName = hscOutName
 346
 347 data HscLang
 348   = HscC
 349   | HscAsm
 350   | HscJava
 351 #ifdef ILX
 352   | HscILX
 353 #endif
 354   | HscInterpreted
 355     deriving (Eq, Show)
 356
 357 dopt_HscLang :: DynFlags -> HscLang
 358 dopt_HscLang = hscLang
 359 \end{code}
 360
 361 %************************************************************************
 362 %*                                                                      *
 363 \subsection{Warnings}
 364 %*                                                                      *
 365 %************************************************************************
 366
 367 \begin{code}
 368 standardWarnings
 369     = [ Opt_WarnDeprecations,
 370         Opt_WarnOverlappingPatterns,
 371         Opt_WarnMissingFields,
 372         Opt_WarnMissingMethods,
 373         Opt_WarnDuplicateExports
 374       ]
 375
 376 minusWOpts
 377     = standardWarnings ++
 378       [ Opt_WarnUnusedBinds,
 379         Opt_WarnUnusedMatches,
 380         Opt_WarnUnusedImports,
 381         Opt_WarnIncompletePatterns
 382       ]
 383
 384 minusWallOpts
 385     = minusWOpts ++
 386       [ Opt_WarnTypeDefaults,
 387         Opt_WarnNameShadowing,
 388         Opt_WarnMissingSigs,
 389         Opt_WarnHiShadows
 390       ]
 391 \end{code}
 392
 393 %************************************************************************
 394 %*                                                                      *
 395 \subsection{Classifying command-line options}
 396 %*                                                                      *
 397 %************************************************************************
 398
 399 \begin{code}
 400 -- v_Statis_hsc_opts is here to avoid a circular dependency with
 401 -- main/DriverState.
 402 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
 403
 404 lookUp           :: FAST_STRING -> Bool
 405 lookup_int       :: String -> Maybe Int
 406 lookup_def_int   :: String -> Int -> Int
 407 lookup_def_float :: String -> Float -> Float
 408 lookup_str       :: String -> Maybe String
 409
 410 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
 411 packed_static_opts   = map _PK_ unpacked_static_opts
 412
 413 lookUp     sw = sw `elem` packed_static_opts
 414
 415 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
 416
 417 lookup_int sw = case (lookup_str sw) of
 418                   Nothing -> Nothing
 419                   Just xx -> Just (read xx)
 420
 421 lookup_def_int sw def = case (lookup_str sw) of
 422                             Nothing -> def              -- Use default
 423                             Just xx -> read xx
 424
 425 lookup_def_float sw def = case (lookup_str sw) of
 426                             Nothing -> def              -- Use default
 427                             Just xx -> read xx
 428
 429
 430 {-
 431  Putting the compiler options into temporary at-files
 432  may turn out to be necessary later on if we turn hsc into
 433  a pure Win32 application where I think there's a command-line
 434  length limit of 255. unpacked_opts understands the @ option.
 435
 436 unpacked_opts :: [String]
 437 unpacked_opts =
 438   concat $
 439   map (expandAts) $
 440   map _UNPK_ argv  -- NOT ARGV any more: v_Static_hsc_opts
 441   where
 442    expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
 443    expandAts l = [l]
 444 -}
 445 \end{code}
 446
 447 %************************************************************************
 448 %*                                                                      *
 449 \subsection{Static options}
 450 %*                                                                      *
 451 %************************************************************************
 452
 453 \begin{code}
 454 -- debugging opts
 455 opt_PprStyle_NoPrags            = lookUp  SLIT("-dppr-noprags")
 456 opt_PprStyle_Debug              = lookUp  SLIT("-dppr-debug")
 457 opt_PprStyle_RawTypes           = lookUp  SLIT("-dppr-rawtypes")
 458 opt_PprUserLength               = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
 459
 460 -- profiling opts
 461 opt_AutoSccsOnAllToplevs        = lookUp  SLIT("-fauto-sccs-on-all-toplevs")
 462 opt_AutoSccsOnExportedToplevs   = lookUp  SLIT("-fauto-sccs-on-exported-toplevs")
 463 opt_AutoSccsOnIndividualCafs    = lookUp  SLIT("-fauto-sccs-on-individual-cafs")
 464 opt_AutoSccsOnDicts             = lookUp  SLIT("-fauto-sccs-on-dicts")
 465 opt_SccProfilingOn              = lookUp  SLIT("-fscc-profiling")
 466 opt_DoTickyProfiling            = lookUp  SLIT("-fticky-ticky")
 467
 468 -- language opts
 469 opt_AllStrict                   = lookUp  SLIT("-fall-strict")
 470 opt_NoMonomorphismRestriction   = lookUp  SLIT("-fno-monomorphism-restriction")
 471 opt_DictsStrict                 = lookUp  SLIT("-fdicts-strict")
 472 opt_IrrefutableTuples           = lookUp  SLIT("-firrefutable-tuples")
 473 opt_MaxContextReductionDepth    = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
 474 opt_NumbersStrict               = lookUp  SLIT("-fnumbers-strict")
 475 opt_Parallel                    = lookUp  SLIT("-fparallel")
 476 opt_SMP                         = lookUp  SLIT("-fsmp")
 477
 478 -- optimisation opts
 479 opt_NoMethodSharing             = lookUp  SLIT("-fno-method-sharing")
 480 opt_DoSemiTagging               = lookUp  SLIT("-fsemi-tagging")
 481 opt_FoldrBuildOn                = lookUp  SLIT("-ffoldr-build-on")
 482 opt_LiberateCaseThreshold       = lookup_def_int "-fliberate-case-threshold" (10::Int)
 483 opt_StgDoLetNoEscapes           = lookUp  SLIT("-flet-no-escape")
 484 opt_UnfoldCasms                 = lookUp  SLIT("-funfold-casms-in-hi-file")
 485 opt_UsageSPOn                   = lookUp  SLIT("-fusagesp-on")
 486 opt_UnboxStrictFields           = lookUp  SLIT("-funbox-strict-fields")
 487
 488 {-
 489    The optional '-inpackage=P' flag tells what package
 490    we are compiling this module for.
 491    The Prelude, for example is compiled with '-inpackage prelude'
 492 -}
 493 opt_InPackage                   = case lookup_str "-inpackage=" of
 494                                     Just p  -> _PK_ p
 495                                     Nothing -> SLIT("Main")     -- The package name if none is specified
 496
 497 opt_EmitCExternDecls            = lookUp  SLIT("-femit-extern-decls")
 498 opt_EnsureSplittableC           = lookUp  SLIT("-fglobalise-toplev-names")
 499 opt_GranMacros                  = lookUp  SLIT("-fgransim")
 500 opt_HiVersion                   = read cProjectVersionInt :: Int
 501 opt_HistorySize                 = lookup_def_int "-fhistory-size" 20
 502 opt_IgnoreAsserts               = lookUp  SLIT("-fignore-asserts")
 503 opt_IgnoreIfacePragmas          = lookUp  SLIT("-fignore-interface-pragmas")
 504 opt_NoHiCheck                   = lookUp  SLIT("-fno-hi-version-check")
 505 opt_OmitBlackHoling             = lookUp  SLIT("-dno-black-holing")
 506 opt_OmitInterfacePragmas        = lookUp  SLIT("-fomit-interface-pragmas")
 507 opt_KeepStgTypes                = lookUp  SLIT("-fkeep-stg-types")
 508
 509 -- Simplifier switches
 510 opt_SimplNoPreInlining          = lookUp  SLIT("-fno-pre-inlining")
 511         -- NoPreInlining is there just to see how bad things
 512         -- get if you don't do it!
 513 opt_SimplDoEtaReduction         = lookUp  SLIT("-fdo-eta-reduction")
 514 opt_SimplDoLambdaEtaExpansion   = lookUp  SLIT("-fdo-lambda-eta-expansion")
 515 opt_SimplCaseMerge              = lookUp  SLIT("-fcase-merge")
 516 opt_SimplExcessPrecision        = lookUp  SLIT("-fexcess-precision")
 517
 518 -- Unfolding control
 519 opt_UF_HiFileThreshold          = lookup_def_int "-funfolding-interface-threshold" (45::Int)
 520 opt_UF_CreationThreshold        = lookup_def_int "-funfolding-creation-threshold"  (45::Int)
 521 opt_UF_UseThreshold             = lookup_def_int "-funfolding-use-threshold"       (8::Int)     -- Discounts can be big
 522 opt_UF_FunAppDiscount           = lookup_def_int "-funfolding-fun-discount"        (6::Int)     -- It's great to inline a fn
 523 opt_UF_KeenessFactor            = lookup_def_float "-funfolding-keeness-factor"    (1.5::Float)
 524 opt_UF_UpdateInPlace            = lookUp  SLIT("-funfolding-update-in-place")
 525
 526 opt_UF_CheapOp  = ( 1 :: Int)   -- Only one instruction; and the args are charged for
 527 opt_UF_DearOp   = ( 4 :: Int)
 528
 529 opt_NoPruneDecls                = lookUp  SLIT("-fno-prune-decls")
 530 opt_NoPruneTyDecls              = lookUp  SLIT("-fno-prune-tydecls")
 531 opt_Static                      = lookUp  SLIT("-static")
 532 opt_Unregisterised              = lookUp  SLIT("-funregisterised")
 533 \end{code}
 534
 535 %************************************************************************
 536 %*                                                                      *
 537 \subsection{List of static hsc flags}
 538 %*                                                                      *
 539 %************************************************************************
 540
 541 \begin{code}
 542 isStaticHscFlag f =
 543   f `elem` [
 544         "fauto-sccs-on-all-toplevs",
 545         "fauto-sccs-on-exported-toplevs",
 546         "fauto-sccs-on-individual-cafs",
 547         "fauto-sccs-on-dicts",
 548         "fscc-profiling",
 549         "fticky-ticky",
 550         "fall-strict",
 551         "fdicts-strict",
 552         "firrefutable-tuples",
 553         "fnumbers-strict",
 554         "fparallel",
 555         "fsmp",
 556         "fsemi-tagging",
 557         "ffoldr-build-on",
 558         "flet-no-escape",
 559         "funfold-casms-in-hi-file",
 560         "fusagesp-on",
 561         "funbox-strict-fields",
 562         "femit-extern-decls",
 563         "fglobalise-toplev-names",
 564         "fgransim",
 565         "fignore-asserts",
 566         "fignore-interface-pragmas",
 567         "fno-hi-version-check",
 568         "dno-black-holing",
 569         "fno-method-sharing",
 570         "fno-monomorphism-restriction",
 571         "fomit-interface-pragmas",
 572         "fkeep-stg-types",
 573         "fno-pre-inlining",
 574         "fdo-eta-reduction",
 575         "fdo-lambda-eta-expansion",
 576         "fcase-merge",
 577         "fexcess-precision",
 578         "funfolding-update-in-place",
 579         "fno-prune-decls",
 580         "fno-prune-tydecls",
 581         "static",
 582         "funregisterised"
 583         ]
 584   || any (flip prefixMatch f) [
 585         "fcontext-stack",
 586         "fliberate-case-threshold",
 587         "fhistory-size",
 588         "funfolding-interface-threshold",
 589         "funfolding-creation-threshold",
 590         "funfolding-use-threshold",
 591         "funfolding-fun-discount",
 592         "funfolding-keeness-factor"
 593      ]
 594 \end{code}
 595
 596 %************************************************************************
 597 %*                                                                      *
 598 \subsection{Switch ordering}
 599 %*                                                                      *
 600 %************************************************************************
 601
 602 These things behave just like enumeration types.
 603
 604 \begin{code}
 605 instance Eq SimplifierSwitch where
 606     a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b
 607
 608 instance Ord SimplifierSwitch where
 609     a <  b  = tagOf_SimplSwitch a <# tagOf_SimplSwitch b
 610     a <= b  = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b
 611
 612
 613 tagOf_SimplSwitch (SimplInlinePhase _)          = _ILIT(1)
 614 tagOf_SimplSwitch (MaxSimplifierIterations _)   = _ILIT(2)
 615 tagOf_SimplSwitch DontApplyRules                = _ILIT(3)
 616 tagOf_SimplSwitch SimplLetToCase                = _ILIT(4)
 617 tagOf_SimplSwitch NoCaseOfCase                  = _ILIT(5)
 618
 619 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 620
 621 lAST_SIMPL_SWITCH_TAG = 5
 622 \end{code}
 623
 624 %************************************************************************
 625 %*                                                                      *
 626 \subsection{Switch lookup}
 627 %*                                                                      *
 628 %************************************************************************
 629
 630 \begin{code}
 631 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 632 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 633                                         -- in the list; defaults right at the end.
 634   = let
 635         tidied_on_switches = foldl rm_dups [] on_switches
 636                 -- The fold*l* ensures that we keep the latest switches;
 637                 -- ie the ones that occur earliest in the list.
 638
 639         sw_tbl :: Array Int SwitchResult
 640         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 641                         all_undefined)
 642                  // defined_elems
 643
 644         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 645
 646         defined_elems = map mk_assoc_elem tidied_on_switches
 647     in
 648     -- (avoid some unboxing, bounds checking, and other horrible things:)
 649 #if __GLASGOW_HASKELL__ < 405
 650     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 651 #else
 652     case sw_tbl of { Array _ _ stuff ->
 653 #endif
 654     \ switch ->
 655         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 656 #if __GLASGOW_HASKELL__ < 400
 657           Lift v -> v
 658 #elif __GLASGOW_HASKELL__ < 403
 659           (# _, v #) -> v
 660 #else
 661           (# v #) -> v
 662 #endif
 663     }
 664   where
 665     mk_assoc_elem k@(MaxSimplifierIterations lvl)
 666         = (iBox (tagOf_SimplSwitch k), SwInt lvl)
 667     mk_assoc_elem k@(SimplInlinePhase n)
 668         = (iBox (tagOf_SimplSwitch k), SwInt n)
 669     mk_assoc_elem k
 670         = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 671
 672     -- cannot have duplicates if we are going to use the array thing
 673     rm_dups switches_so_far switch
 674       = if switch `is_elem` switches_so_far
 675         then switches_so_far
 676         else switch : switches_so_far
 677       where
 678         sw `is_elem` []     = False
 679         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s)
 680                             || sw `is_elem` ss
 681 \end{code}
 682
 683
 684 %************************************************************************
 685 %*                                                                      *
 686 \subsection{Misc functions for command-line options}
 687 %*                                                                      *
 688 %************************************************************************
 689
 690
 691 \begin{code}
 692 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 693
 694 switchIsOn lookup_fn switch
 695   = case (lookup_fn switch) of
 696       SwBool False -> False
 697       _            -> True
 698
 699 intSwitchSet :: (switch -> SwitchResult)
 700              -> (Int -> switch)
 701              -> Maybe Int
 702
 703 intSwitchSet lookup_fn switch
 704   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 705       SwInt int -> Just int
 706       _         -> Nothing
 707 \end{code}
 708
 709 \begin{code}
 710 startsWith :: String -> String -> Maybe String
 711 -- startsWith pfx (pfx++rest) = Just rest
 712
 713 startsWith []     str = Just str
 714 startsWith (c:cs) (s:ss)
 715   = if c /= s then Nothing else startsWith cs ss
 716 startsWith  _     []  = Nothing
 717
 718 endsWith  :: String -> String -> Maybe String
 719 endsWith cs ss
 720   = case (startsWith (reverse cs) (reverse ss)) of
 721       Nothing -> Nothing
 722       Just rs -> Just (reverse rs)
 723 \end{code}