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_CreationThreshold,
  79         opt_UF_UseThreshold,
  80         opt_UF_FunAppDiscount,
  81         opt_UF_KeenessFactor,
  82         opt_UF_UpdateInPlace,
  83         opt_UF_CheapOp,
  84         opt_UF_DearOp,
  85
  86         -- misc opts
  87         opt_InPackage,
  88         opt_EmitCExternDecls,
  89         opt_EnsureSplittableC,
  90         opt_GranMacros,
  91         opt_HiVersion,
  92         opt_HistorySize,
  93         opt_IgnoreAsserts,
  94         opt_IgnoreIfacePragmas,
  95         opt_NoHiCheck,
  96         opt_OmitBlackHoling,
  97         opt_OmitInterfacePragmas,
  98         opt_NoPruneTyDecls,
  99         opt_NoPruneDecls,
 100         opt_Static,
 101         opt_Unregisterised
 102     ) where
 103
 104 #include "HsVersions.h"
 105
 106 import Array    ( array, (//) )
 107 import GlaExts
 108 import IOExts   ( IORef, readIORef )
 109 import Constants        -- Default values for some flags
 110 import Util
 111 import FastTypes
 112 import Config
 113
 114 import Maybes           ( firstJust )
 115 import Panic            ( panic )
 116
 117 #if __GLASGOW_HASKELL__ < 301
 118 import ArrBase  ( Array(..) )
 119 #else
 120 import PrelArr  ( Array(..) )
 121 #endif
 122 \end{code}
 123
 124 %************************************************************************
 125 %*                                                                      *
 126 \subsection{Command-line options}
 127 %*                                                                      *
 128 %************************************************************************
 129
 130 The hsc command-line options are split into two categories:
 131
 132   - static flags
 133   - dynamic flags
 134
 135 Static flags are represented by top-level values of type Bool or Int,
 136 for example.  They therefore have the same value throughout the
 137 invocation of hsc.
 138
 139 Dynamic flags are represented by an abstract type, DynFlags, which is
 140 passed into hsc by the compilation manager for every compilation.
 141 Dynamic flags are those that change on a per-compilation basis,
 142 perhaps because they may be present in the OPTIONS pragma at the top
 143 of a module.
 144
 145 Other flag-related blurb:
 146
 147 A list of {\em ToDo}s is things to be done in a particular part of
 148 processing.  A (fictitious) example for the Core-to-Core simplifier
 149 might be: run the simplifier, then run the strictness analyser, then
 150 run the simplifier again (three ``todos'').
 151
 152 There are three ``to-do processing centers'' at the moment.  In the
 153 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
 154 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
 155 (\tr{simplStg/SimplStg.lhs}).
 156
 157 %************************************************************************
 158 %*                                                                      *
 159 \subsection{Datatypes associated with command-line options}
 160 %*                                                                      *
 161 %************************************************************************
 162
 163 \begin{code}
 164 data SwitchResult
 165   = SwBool      Bool            -- on/off
 166   | SwString    FAST_STRING     -- nothing or a String
 167   | SwInt       Int             -- nothing or an Int
 168 \end{code}
 169
 170 \begin{code}
 171 data CoreToDo           -- These are diff core-to-core passes,
 172                         -- which may be invoked in any order,
 173                         -- as many times as you like.
 174
 175   = CoreDoSimplify      -- The core-to-core simplifier.
 176         (SimplifierSwitch -> SwitchResult)
 177                         -- Each run of the simplifier can take a different
 178                         -- set of simplifier-specific flags.
 179   | CoreDoFloatInwards
 180   | CoreDoFloatOutwards Bool    -- True <=> float lambdas to top level
 181   | CoreLiberateCase
 182   | CoreDoPrintCore
 183   | CoreDoStaticArgs
 184   | CoreDoStrictness
 185   | CoreDoWorkerWrapper
 186   | CoreDoSpecialising
 187   | CoreDoSpecConstr
 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 std'
 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_CreationThreshold        = lookup_def_int "-funfolding-creation-threshold"  (45::Int)
 520 opt_UF_UseThreshold             = lookup_def_int "-funfolding-use-threshold"       (8::Int)     -- Discounts can be big
 521 opt_UF_FunAppDiscount           = lookup_def_int "-funfolding-fun-discount"        (6::Int)     -- It's great to inline a fn
 522 opt_UF_KeenessFactor            = lookup_def_float "-funfolding-keeness-factor"    (1.5::Float)
 523 opt_UF_UpdateInPlace            = lookUp  SLIT("-funfolding-update-in-place")
 524
 525 opt_UF_CheapOp  = ( 1 :: Int)   -- Only one instruction; and the args are charged for
 526 opt_UF_DearOp   = ( 4 :: Int)
 527
 528 opt_NoPruneDecls                = lookUp  SLIT("-fno-prune-decls")
 529 opt_NoPruneTyDecls              = lookUp  SLIT("-fno-prune-tydecls")
 530 opt_Static                      = lookUp  SLIT("-static")
 531 opt_Unregisterised              = lookUp  SLIT("-funregisterised")
 532 \end{code}
 533
 534 %************************************************************************
 535 %*                                                                      *
 536 \subsection{List of static hsc flags}
 537 %*                                                                      *
 538 %************************************************************************
 539
 540 \begin{code}
 541 isStaticHscFlag f =
 542   f `elem` [
 543         "fauto-sccs-on-all-toplevs",
 544         "fauto-sccs-on-exported-toplevs",
 545         "fauto-sccs-on-individual-cafs",
 546         "fauto-sccs-on-dicts",
 547         "fscc-profiling",
 548         "fticky-ticky",
 549         "fall-strict",
 550         "fdicts-strict",
 551         "firrefutable-tuples",
 552         "fnumbers-strict",
 553         "fparallel",
 554         "fsmp",
 555         "fsemi-tagging",
 556         "ffoldr-build-on",
 557         "flet-no-escape",
 558         "funfold-casms-in-hi-file",
 559         "fusagesp-on",
 560         "funbox-strict-fields",
 561         "femit-extern-decls",
 562         "fglobalise-toplev-names",
 563         "fgransim",
 564         "fignore-asserts",
 565         "fignore-interface-pragmas",
 566         "fno-hi-version-check",
 567         "dno-black-holing",
 568         "fno-method-sharing",
 569         "fno-monomorphism-restriction",
 570         "fomit-interface-pragmas",
 571         "fkeep-stg-types",
 572         "fno-pre-inlining",
 573         "fdo-eta-reduction",
 574         "fdo-lambda-eta-expansion",
 575         "fcase-merge",
 576         "fexcess-precision",
 577         "funfolding-update-in-place",
 578         "fno-prune-decls",
 579         "fno-prune-tydecls",
 580         "static",
 581         "funregisterised"
 582         ]
 583   || any (flip prefixMatch f) [
 584         "fcontext-stack",
 585         "fliberate-case-threshold",
 586         "fhistory-size",
 587         "funfolding-creation-threshold",
 588         "funfolding-use-threshold",
 589         "funfolding-fun-discount",
 590         "funfolding-keeness-factor"
 591      ]
 592 \end{code}
 593
 594 %************************************************************************
 595 %*                                                                      *
 596 \subsection{Switch ordering}
 597 %*                                                                      *
 598 %************************************************************************
 599
 600 These things behave just like enumeration types.
 601
 602 \begin{code}
 603 instance Eq SimplifierSwitch where
 604     a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b
 605
 606 instance Ord SimplifierSwitch where
 607     a <  b  = tagOf_SimplSwitch a <# tagOf_SimplSwitch b
 608     a <= b  = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b
 609
 610
 611 tagOf_SimplSwitch (SimplInlinePhase _)          = _ILIT(1)
 612 tagOf_SimplSwitch (MaxSimplifierIterations _)   = _ILIT(2)
 613 tagOf_SimplSwitch DontApplyRules                = _ILIT(3)
 614 tagOf_SimplSwitch SimplLetToCase                = _ILIT(4)
 615 tagOf_SimplSwitch NoCaseOfCase                  = _ILIT(5)
 616
 617 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 618
 619 lAST_SIMPL_SWITCH_TAG = 5
 620 \end{code}
 621
 622 %************************************************************************
 623 %*                                                                      *
 624 \subsection{Switch lookup}
 625 %*                                                                      *
 626 %************************************************************************
 627
 628 \begin{code}
 629 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 630 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 631                                         -- in the list; defaults right at the end.
 632   = let
 633         tidied_on_switches = foldl rm_dups [] on_switches
 634                 -- The fold*l* ensures that we keep the latest switches;
 635                 -- ie the ones that occur earliest in the list.
 636
 637         sw_tbl :: Array Int SwitchResult
 638         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 639                         all_undefined)
 640                  // defined_elems
 641
 642         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 643
 644         defined_elems = map mk_assoc_elem tidied_on_switches
 645     in
 646     -- (avoid some unboxing, bounds checking, and other horrible things:)
 647 #if __GLASGOW_HASKELL__ < 405
 648     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 649 #else
 650     case sw_tbl of { Array _ _ stuff ->
 651 #endif
 652     \ switch ->
 653         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 654 #if __GLASGOW_HASKELL__ < 400
 655           Lift v -> v
 656 #elif __GLASGOW_HASKELL__ < 403
 657           (# _, v #) -> v
 658 #else
 659           (# v #) -> v
 660 #endif
 661     }
 662   where
 663     mk_assoc_elem k@(MaxSimplifierIterations lvl)
 664         = (iBox (tagOf_SimplSwitch k), SwInt lvl)
 665     mk_assoc_elem k@(SimplInlinePhase n)
 666         = (iBox (tagOf_SimplSwitch k), SwInt n)
 667     mk_assoc_elem k
 668         = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 669
 670     -- cannot have duplicates if we are going to use the array thing
 671     rm_dups switches_so_far switch
 672       = if switch `is_elem` switches_so_far
 673         then switches_so_far
 674         else switch : switches_so_far
 675       where
 676         sw `is_elem` []     = False
 677         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s)
 678                             || sw `is_elem` ss
 679 \end{code}
 680
 681
 682 %************************************************************************
 683 %*                                                                      *
 684 \subsection{Misc functions for command-line options}
 685 %*                                                                      *
 686 %************************************************************************
 687
 688
 689 \begin{code}
 690 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 691
 692 switchIsOn lookup_fn switch
 693   = case (lookup_fn switch) of
 694       SwBool False -> False
 695       _            -> True
 696
 697 intSwitchSet :: (switch -> SwitchResult)
 698              -> (Int -> switch)
 699              -> Maybe Int
 700
 701 intSwitchSet lookup_fn switch
 702   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 703       SwInt int -> Just int
 704       _         -> Nothing
 705 \end{code}
 706
 707 \begin{code}
 708 startsWith :: String -> String -> Maybe String
 709 -- startsWith pfx (pfx++rest) = Just rest
 710
 711 startsWith []     str = Just str
 712 startsWith (c:cs) (s:ss)
 713   = if c /= s then Nothing else startsWith cs ss
 714 startsWith  _     []  = Nothing
 715
 716 endsWith  :: String -> String -> Maybe String
 717 endsWith cs ss
 718   = case (startsWith (reverse cs) (reverse ss)) of
 719       Nothing -> Nothing
 720       Just rs -> Just (reverse rs)
 721 \end{code}