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         dopt_set,
  32         dopt_unset,
  33
  34         -- other dynamic flags
  35         dopt_CoreToDo,
  36         dopt_StgToDo,
  37         dopt_HscLang,
  38         dopt_OutName,
  39
  40         -- sets of warning opts
  41         standardWarnings,
  42         minusWOpts,
  43         minusWallOpts,
  44
  45         -- profiling opts
  46         opt_AutoSccsOnAllToplevs,
  47         opt_AutoSccsOnExportedToplevs,
  48         opt_AutoSccsOnIndividualCafs,
  49         opt_AutoSccsOnDicts,
  50         opt_SccProfilingOn,
  51         opt_DoTickyProfiling,
  52
  53         -- language opts
  54         opt_AllStrict,
  55         opt_DictsStrict,
  56         opt_MaxContextReductionDepth,
  57         opt_IrrefutableTuples,
  58         opt_NumbersStrict,
  59         opt_Parallel,
  60         opt_SMP,
  61         opt_NoMonomorphismRestriction,
  62         opt_RuntimeTypes,
  63
  64         -- optimisation opts
  65         opt_NoMethodSharing,
  66         opt_DoSemiTagging,
  67         opt_FoldrBuildOn,
  68         opt_LiberateCaseThreshold,
  69         opt_StgDoLetNoEscapes,
  70         opt_UnfoldCasms,
  71         opt_UsageSPOn,
  72         opt_UnboxStrictFields,
  73         opt_SimplNoPreInlining,
  74         opt_SimplDoEtaReduction,
  75         opt_SimplDoLambdaEtaExpansion,
  76         opt_SimplCaseMerge,
  77         opt_SimplExcessPrecision,
  78
  79         -- Unfolding control
  80         opt_UF_CreationThreshold,
  81         opt_UF_UseThreshold,
  82         opt_UF_FunAppDiscount,
  83         opt_UF_KeenessFactor,
  84         opt_UF_UpdateInPlace,
  85         opt_UF_CheapOp,
  86         opt_UF_DearOp,
  87
  88         -- misc opts
  89         opt_InPackage,
  90         opt_EmitCExternDecls,
  91         opt_EnsureSplittableC,
  92         opt_GranMacros,
  93         opt_HiVersion,
  94         opt_HistorySize,
  95         opt_IgnoreAsserts,
  96         opt_IgnoreIfacePragmas,
  97         opt_NoHiCheck,
  98         opt_OmitBlackHoling,
  99         opt_OmitInterfacePragmas,
 100         opt_NoPruneTyDecls,
 101         opt_NoPruneDecls,
 102         opt_Static,
 103         opt_Unregisterised,
 104         opt_EmitExternalCore
 105     ) where
 106
 107 #include "HsVersions.h"
 108
 109 import Array    ( array, (//) )
 110 import GlaExts
 111 import IOExts   ( IORef, readIORef )
 112 import Constants        -- Default values for some flags
 113 import Util
 114 import FastTypes
 115 import Config
 116
 117 import Maybes           ( firstJust )
 118 import Panic            ( panic )
 119
 120 #if __GLASGOW_HASKELL__ < 301
 121 import ArrBase  ( Array(..) )
 122 #else
 123 import PrelArr  ( Array(..) )
 124 #endif
 125 \end{code}
 126
 127 %************************************************************************
 128 %*                                                                      *
 129 \subsection{Command-line options}
 130 %*                                                                      *
 131 %************************************************************************
 132
 133 The hsc command-line options are split into two categories:
 134
 135   - static flags
 136   - dynamic flags
 137
 138 Static flags are represented by top-level values of type Bool or Int,
 139 for example.  They therefore have the same value throughout the
 140 invocation of hsc.
 141
 142 Dynamic flags are represented by an abstract type, DynFlags, which is
 143 passed into hsc by the compilation manager for every compilation.
 144 Dynamic flags are those that change on a per-compilation basis,
 145 perhaps because they may be present in the OPTIONS pragma at the top
 146 of a module.
 147
 148 Other flag-related blurb:
 149
 150 A list of {\em ToDo}s is things to be done in a particular part of
 151 processing.  A (fictitious) example for the Core-to-Core simplifier
 152 might be: run the simplifier, then run the strictness analyser, then
 153 run the simplifier again (three ``todos'').
 154
 155 There are three ``to-do processing centers'' at the moment.  In the
 156 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
 157 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
 158 (\tr{simplStg/SimplStg.lhs}).
 159
 160 %************************************************************************
 161 %*                                                                      *
 162 \subsection{Datatypes associated with command-line options}
 163 %*                                                                      *
 164 %************************************************************************
 165
 166 \begin{code}
 167 data SwitchResult
 168   = SwBool      Bool            -- on/off
 169   | SwString    FAST_STRING     -- nothing or a String
 170   | SwInt       Int             -- nothing or an Int
 171 \end{code}
 172
 173 \begin{code}
 174 data CoreToDo           -- These are diff core-to-core passes,
 175                         -- which may be invoked in any order,
 176                         -- as many times as you like.
 177
 178   = CoreDoSimplify      -- The core-to-core simplifier.
 179         (SimplifierSwitch -> SwitchResult)
 180                         -- Each run of the simplifier can take a different
 181                         -- set of simplifier-specific flags.
 182   | CoreDoFloatInwards
 183   | CoreDoFloatOutwards Bool    -- True <=> float lambdas to top level
 184   | CoreLiberateCase
 185   | CoreDoPrintCore
 186   | CoreDoStaticArgs
 187   | CoreDoStrictness
 188   | CoreDoWorkerWrapper
 189   | CoreDoSpecialising
 190   | CoreDoSpecConstr
 191   | CoreDoUSPInf
 192   | CoreDoCPResult
 193   | CoreDoGlomBinds
 194   | CoreCSE
 195
 196   | CoreDoNothing        -- useful when building up lists of these things
 197 \end{code}
 198
 199 \begin{code}
 200 data StgToDo
 201   = StgDoMassageForProfiling  -- should be (next to) last
 202   -- There's also setStgVarInfo, but its absolute "lastness"
 203   -- is so critical that it is hardwired in (no flag).
 204   | D_stg_stats
 205 \end{code}
 206
 207 \begin{code}
 208 data SimplifierSwitch
 209   = MaxSimplifierIterations Int
 210   | SimplInlinePhase Int
 211   | DontApplyRules
 212   | NoCaseOfCase
 213   | SimplLetToCase
 214 \end{code}
 215
 216 %************************************************************************
 217 %*                                                                      *
 218 \subsection{Dynamic command-line options}
 219 %*                                                                      *
 220 %************************************************************************
 221
 222 \begin{code}
 223 data DynFlag
 224
 225    -- debugging flags
 226    = Opt_D_dump_absC
 227    | Opt_D_dump_asm
 228    | Opt_D_dump_cpranal
 229    | Opt_D_dump_deriv
 230    | Opt_D_dump_ds
 231    | Opt_D_dump_flatC
 232    | Opt_D_dump_foreign
 233    | Opt_D_dump_inlinings
 234    | Opt_D_dump_occur_anal
 235    | Opt_D_dump_parsed
 236    | Opt_D_dump_realC
 237    | Opt_D_dump_rn
 238    | Opt_D_dump_simpl
 239    | Opt_D_dump_simpl_iterations
 240    | Opt_D_dump_spec
 241    | Opt_D_dump_sat
 242    | Opt_D_dump_stg
 243    | Opt_D_dump_stranal
 244    | Opt_D_dump_tc
 245    | Opt_D_dump_types
 246    | Opt_D_dump_rules
 247    | Opt_D_dump_usagesp
 248    | Opt_D_dump_cse
 249    | Opt_D_dump_worker_wrapper
 250    | Opt_D_dump_rn_trace
 251    | Opt_D_dump_rn_stats
 252    | Opt_D_dump_stix
 253    | Opt_D_dump_simpl_stats
 254    | Opt_D_dump_tc_trace
 255    | Opt_D_dump_BCOs
 256    | Opt_D_source_stats
 257    | Opt_D_verbose_core2core
 258    | Opt_D_verbose_stg2stg
 259    | Opt_D_dump_hi
 260    | Opt_D_dump_hi_diffs
 261    | Opt_D_dump_minimal_imports
 262    | Opt_DoCoreLinting
 263    | Opt_DoStgLinting
 264    | Opt_DoUSPLinting
 265
 266    | Opt_WarnDuplicateExports
 267    | Opt_WarnHiShadows
 268    | Opt_WarnIncompletePatterns
 269    | Opt_WarnMissingFields
 270    | Opt_WarnMissingMethods
 271    | Opt_WarnMissingSigs
 272    | Opt_WarnNameShadowing
 273    | Opt_WarnOverlappingPatterns
 274    | Opt_WarnSimplePatterns
 275    | Opt_WarnTypeDefaults
 276    | Opt_WarnUnusedBinds
 277    | Opt_WarnUnusedImports
 278    | Opt_WarnUnusedMatches
 279    | Opt_WarnDeprecations
 280    | Opt_WarnMisc
 281
 282    -- language opts
 283    | Opt_AllowOverlappingInstances
 284    | Opt_AllowUndecidableInstances
 285    | Opt_GlasgowExts
 286    | Opt_Generics
 287    | Opt_NoImplicitPrelude
 288
 289    deriving (Eq)
 290
 291 data DynFlags = DynFlags {
 292   coreToDo              :: [CoreToDo],
 293   stgToDo               :: [StgToDo],
 294   hscLang               :: HscLang,
 295   hscOutName            :: String,      -- name of the output file
 296   hscStubHOutName       :: String,      -- name of the .stub_h output file
 297   hscStubCOutName       :: String,      -- name of the .stub_c output file
 298   extCoreName           :: String,      -- name of the .core output file
 299   verbosity             :: Int,         -- verbosity level
 300   cppFlag               :: Bool,        -- preprocess with cpp?
 301   stolen_x86_regs       :: Int,
 302   cmdlineHcIncludes     :: [String],    -- -#includes
 303
 304   -- options for particular phases
 305   opt_L                 :: [String],
 306   opt_P                 :: [String],
 307   opt_c                 :: [String],
 308   opt_a                 :: [String],
 309   opt_m                 :: [String],
 310
 311   -- hsc dynamic flags
 312   flags                 :: [DynFlag]
 313  }
 314
 315 defaultDynFlags = DynFlags {
 316   coreToDo = [], stgToDo = [],
 317   hscLang = HscC,
 318   hscOutName = "",
 319   hscStubHOutName = "", hscStubCOutName = "",
 320   extCoreName = "",
 321   verbosity = 0,
 322   cppFlag               = False,
 323   stolen_x86_regs       = 4,
 324   cmdlineHcIncludes     = [],
 325   opt_L                 = [],
 326   opt_P                 = [],
 327   opt_c                 = [],
 328   opt_a                 = [],
 329   opt_m                 = [],
 330   flags = standardWarnings,
 331   }
 332
 333 {-
 334     Verbosity levels:
 335
 336     0   |   print errors & warnings only
 337     1   |   minimal verbosity: print "compiling M ... done." for each module.
 338     2   |   equivalent to -dshow-passes
 339     3   |   equivalent to existing "ghc -v"
 340     4   |   "ghc -v -ddump-most"
 341     5   |   "ghc -v -ddump-all"
 342 -}
 343
 344 dopt :: DynFlag -> DynFlags -> Bool
 345 dopt f dflags  = f `elem` (flags dflags)
 346
 347 dopt_CoreToDo :: DynFlags -> [CoreToDo]
 348 dopt_CoreToDo = coreToDo
 349
 350 dopt_StgToDo :: DynFlags -> [StgToDo]
 351 dopt_StgToDo = stgToDo
 352
 353 dopt_OutName :: DynFlags -> String
 354 dopt_OutName = hscOutName
 355
 356 dopt_set :: DynFlags -> DynFlag -> DynFlags
 357 dopt_set dfs f = dfs{ flags = f : flags dfs }
 358
 359 dopt_unset :: DynFlags -> DynFlag -> DynFlags
 360 dopt_unset dfs f = dfs{ flags = filter (/= f) (flags dfs) }
 361
 362 data HscLang
 363   = HscC
 364   | HscAsm
 365   | HscJava
 366   | HscILX
 367   | HscInterpreted
 368     deriving (Eq, Show)
 369
 370 dopt_HscLang :: DynFlags -> HscLang
 371 dopt_HscLang = hscLang
 372 \end{code}
 373
 374 %************************************************************************
 375 %*                                                                      *
 376 \subsection{Warnings}
 377 %*                                                                      *
 378 %************************************************************************
 379
 380 \begin{code}
 381 standardWarnings
 382     = [ Opt_WarnDeprecations,
 383         Opt_WarnOverlappingPatterns,
 384         Opt_WarnMissingFields,
 385         Opt_WarnMissingMethods,
 386         Opt_WarnDuplicateExports
 387       ]
 388
 389 minusWOpts
 390     = standardWarnings ++
 391       [ Opt_WarnUnusedBinds,
 392         Opt_WarnUnusedMatches,
 393         Opt_WarnUnusedImports,
 394         Opt_WarnIncompletePatterns,
 395         Opt_WarnMisc
 396       ]
 397
 398 minusWallOpts
 399     = minusWOpts ++
 400       [ Opt_WarnTypeDefaults,
 401         Opt_WarnNameShadowing,
 402         Opt_WarnMissingSigs,
 403         Opt_WarnHiShadows
 404       ]
 405 \end{code}
 406
 407 %************************************************************************
 408 %*                                                                      *
 409 \subsection{Classifying command-line options}
 410 %*                                                                      *
 411 %************************************************************************
 412
 413 \begin{code}
 414 -- v_Statis_hsc_opts is here to avoid a circular dependency with
 415 -- main/DriverState.
 416 GLOBAL_VAR(v_Static_hsc_opts, [], [String])
 417
 418 lookUp           :: FAST_STRING -> Bool
 419 lookup_int       :: String -> Maybe Int
 420 lookup_def_int   :: String -> Int -> Int
 421 lookup_def_float :: String -> Float -> Float
 422 lookup_str       :: String -> Maybe String
 423
 424 unpacked_static_opts = unsafePerformIO (readIORef v_Static_hsc_opts)
 425 packed_static_opts   = map _PK_ unpacked_static_opts
 426
 427 lookUp     sw = sw `elem` packed_static_opts
 428
 429 lookup_str sw = firstJust (map (startsWith sw) unpacked_static_opts)
 430
 431 lookup_int sw = case (lookup_str sw) of
 432                   Nothing -> Nothing
 433                   Just xx -> Just (read xx)
 434
 435 lookup_def_int sw def = case (lookup_str sw) of
 436                             Nothing -> def              -- Use default
 437                             Just xx -> read xx
 438
 439 lookup_def_float sw def = case (lookup_str sw) of
 440                             Nothing -> def              -- Use default
 441                             Just xx -> read xx
 442
 443
 444 {-
 445  Putting the compiler options into temporary at-files
 446  may turn out to be necessary later on if we turn hsc into
 447  a pure Win32 application where I think there's a command-line
 448  length limit of 255. unpacked_opts understands the @ option.
 449
 450 unpacked_opts :: [String]
 451 unpacked_opts =
 452   concat $
 453   map (expandAts) $
 454   map _UNPK_ argv  -- NOT ARGV any more: v_Static_hsc_opts
 455   where
 456    expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
 457    expandAts l = [l]
 458 -}
 459 \end{code}
 460
 461 %************************************************************************
 462 %*                                                                      *
 463 \subsection{Static options}
 464 %*                                                                      *
 465 %************************************************************************
 466
 467 \begin{code}
 468 -- debugging opts
 469 opt_PprStyle_NoPrags            = lookUp  SLIT("-dppr-noprags")
 470 opt_PprStyle_Debug              = lookUp  SLIT("-dppr-debug")
 471 opt_PprStyle_RawTypes           = lookUp  SLIT("-dppr-rawtypes")
 472 opt_PprUserLength               = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
 473
 474 -- profiling opts
 475 opt_AutoSccsOnAllToplevs        = lookUp  SLIT("-fauto-sccs-on-all-toplevs")
 476 opt_AutoSccsOnExportedToplevs   = lookUp  SLIT("-fauto-sccs-on-exported-toplevs")
 477 opt_AutoSccsOnIndividualCafs    = lookUp  SLIT("-fauto-sccs-on-individual-cafs")
 478 opt_AutoSccsOnDicts             = lookUp  SLIT("-fauto-sccs-on-dicts")
 479 opt_SccProfilingOn              = lookUp  SLIT("-fscc-profiling")
 480 opt_DoTickyProfiling            = lookUp  SLIT("-fticky-ticky")
 481
 482 -- language opts
 483 opt_AllStrict                   = lookUp  SLIT("-fall-strict")
 484 opt_NoMonomorphismRestriction   = lookUp  SLIT("-fno-monomorphism-restriction")
 485 opt_DictsStrict                 = lookUp  SLIT("-fdicts-strict")
 486 opt_IrrefutableTuples           = lookUp  SLIT("-firrefutable-tuples")
 487 opt_MaxContextReductionDepth    = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
 488 opt_NumbersStrict               = lookUp  SLIT("-fnumbers-strict")
 489 opt_Parallel                    = lookUp  SLIT("-fparallel")
 490 opt_SMP                         = lookUp  SLIT("-fsmp")
 491
 492 -- optimisation opts
 493 opt_NoMethodSharing             = lookUp  SLIT("-fno-method-sharing")
 494 opt_DoSemiTagging               = lookUp  SLIT("-fsemi-tagging")
 495 opt_FoldrBuildOn                = lookUp  SLIT("-ffoldr-build-on")
 496 opt_LiberateCaseThreshold       = lookup_def_int "-fliberate-case-threshold" (10::Int)
 497 opt_StgDoLetNoEscapes           = lookUp  SLIT("-flet-no-escape")
 498 opt_UnfoldCasms                 = lookUp  SLIT("-funfold-casms-in-hi-file")
 499 opt_UsageSPOn                   = lookUp  SLIT("-fusagesp-on")
 500 opt_UnboxStrictFields           = lookUp  SLIT("-funbox-strict-fields")
 501
 502 {-
 503    The optional '-inpackage=P' flag tells what package
 504    we are compiling this module for.
 505    The Prelude, for example is compiled with '-inpackage std'
 506 -}
 507 opt_InPackage                   = case lookup_str "-inpackage=" of
 508                                     Just p  -> _PK_ p
 509                                     Nothing -> SLIT("Main")     -- The package name if none is specified
 510
 511 opt_EmitCExternDecls            = lookUp  SLIT("-femit-extern-decls")
 512 opt_EnsureSplittableC           = lookUp  SLIT("-fglobalise-toplev-names")
 513 opt_GranMacros                  = lookUp  SLIT("-fgransim")
 514 opt_HiVersion                   = read cProjectVersionInt :: Int
 515 opt_HistorySize                 = lookup_def_int "-fhistory-size" 20
 516 opt_IgnoreAsserts               = lookUp  SLIT("-fignore-asserts")
 517 opt_IgnoreIfacePragmas          = lookUp  SLIT("-fignore-interface-pragmas")
 518 opt_NoHiCheck                   = lookUp  SLIT("-fno-hi-version-check")
 519 opt_OmitBlackHoling             = lookUp  SLIT("-dno-black-holing")
 520 opt_OmitInterfacePragmas        = lookUp  SLIT("-fomit-interface-pragmas")
 521 opt_RuntimeTypes                = lookUp  SLIT("-fruntime-types")
 522
 523 -- Simplifier switches
 524 opt_SimplNoPreInlining          = lookUp  SLIT("-fno-pre-inlining")
 525         -- NoPreInlining is there just to see how bad things
 526         -- get if you don't do it!
 527 opt_SimplDoEtaReduction         = lookUp  SLIT("-fdo-eta-reduction")
 528 opt_SimplDoLambdaEtaExpansion   = lookUp  SLIT("-fdo-lambda-eta-expansion")
 529 opt_SimplCaseMerge              = lookUp  SLIT("-fcase-merge")
 530 opt_SimplExcessPrecision        = lookUp  SLIT("-fexcess-precision")
 531
 532 -- Unfolding control
 533 opt_UF_CreationThreshold        = lookup_def_int "-funfolding-creation-threshold"  (45::Int)
 534 opt_UF_UseThreshold             = lookup_def_int "-funfolding-use-threshold"       (8::Int)     -- Discounts can be big
 535 opt_UF_FunAppDiscount           = lookup_def_int "-funfolding-fun-discount"        (6::Int)     -- It's great to inline a fn
 536 opt_UF_KeenessFactor            = lookup_def_float "-funfolding-keeness-factor"    (1.5::Float)
 537 opt_UF_UpdateInPlace            = lookUp  SLIT("-funfolding-update-in-place")
 538
 539 opt_UF_CheapOp  = ( 1 :: Int)   -- Only one instruction; and the args are charged for
 540 opt_UF_DearOp   = ( 4 :: Int)
 541
 542 opt_NoPruneDecls                = lookUp  SLIT("-fno-prune-decls")
 543 opt_NoPruneTyDecls              = lookUp  SLIT("-fno-prune-tydecls")
 544 opt_Static                      = lookUp  SLIT("-static")
 545 opt_Unregisterised              = lookUp  SLIT("-funregisterised")
 546 opt_EmitExternalCore            = lookUp  SLIT("-fext-core")
 547 \end{code}
 548
 549 %************************************************************************
 550 %*                                                                      *
 551 \subsection{List of static hsc flags}
 552 %*                                                                      *
 553 %************************************************************************
 554
 555 \begin{code}
 556 isStaticHscFlag f =
 557   f `elem` [
 558         "fauto-sccs-on-all-toplevs",
 559         "fauto-sccs-on-exported-toplevs",
 560         "fauto-sccs-on-individual-cafs",
 561         "fauto-sccs-on-dicts",
 562         "fscc-profiling",
 563         "fticky-ticky",
 564         "fall-strict",
 565         "fdicts-strict",
 566         "firrefutable-tuples",
 567         "fnumbers-strict",
 568         "fparallel",
 569         "fsmp",
 570         "fsemi-tagging",
 571         "ffoldr-build-on",
 572         "flet-no-escape",
 573         "funfold-casms-in-hi-file",
 574         "fusagesp-on",
 575         "funbox-strict-fields",
 576         "femit-extern-decls",
 577         "fglobalise-toplev-names",
 578         "fgransim",
 579         "fignore-asserts",
 580         "fignore-interface-pragmas",
 581         "fno-hi-version-check",
 582         "dno-black-holing",
 583         "fno-method-sharing",
 584         "fno-monomorphism-restriction",
 585         "fomit-interface-pragmas",
 586         "fruntime-types",
 587         "fno-pre-inlining",
 588         "fdo-eta-reduction",
 589         "fdo-lambda-eta-expansion",
 590         "fcase-merge",
 591         "fexcess-precision",
 592         "funfolding-update-in-place",
 593         "fno-prune-decls",
 594         "fno-prune-tydecls",
 595         "static",
 596         "funregisterised",
 597         "fext-core"
 598         ]
 599   || any (flip prefixMatch f) [
 600         "fcontext-stack",
 601         "fliberate-case-threshold",
 602         "fhistory-size",
 603         "funfolding-creation-threshold",
 604         "funfolding-use-threshold",
 605         "funfolding-fun-discount",
 606         "funfolding-keeness-factor"
 607      ]
 608 \end{code}
 609
 610 %************************************************************************
 611 %*                                                                      *
 612 \subsection{Switch ordering}
 613 %*                                                                      *
 614 %************************************************************************
 615
 616 These things behave just like enumeration types.
 617
 618 \begin{code}
 619 instance Eq SimplifierSwitch where
 620     a == b = tagOf_SimplSwitch a ==# tagOf_SimplSwitch b
 621
 622 instance Ord SimplifierSwitch where
 623     a <  b  = tagOf_SimplSwitch a <# tagOf_SimplSwitch b
 624     a <= b  = tagOf_SimplSwitch a <=# tagOf_SimplSwitch b
 625
 626
 627 tagOf_SimplSwitch (SimplInlinePhase _)          = _ILIT(1)
 628 tagOf_SimplSwitch (MaxSimplifierIterations _)   = _ILIT(2)
 629 tagOf_SimplSwitch DontApplyRules                = _ILIT(3)
 630 tagOf_SimplSwitch SimplLetToCase                = _ILIT(4)
 631 tagOf_SimplSwitch NoCaseOfCase                  = _ILIT(5)
 632
 633 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 634
 635 lAST_SIMPL_SWITCH_TAG = 5
 636 \end{code}
 637
 638 %************************************************************************
 639 %*                                                                      *
 640 \subsection{Switch lookup}
 641 %*                                                                      *
 642 %************************************************************************
 643
 644 \begin{code}
 645 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 646 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 647                                         -- in the list; defaults right at the end.
 648   = let
 649         tidied_on_switches = foldl rm_dups [] on_switches
 650                 -- The fold*l* ensures that we keep the latest switches;
 651                 -- ie the ones that occur earliest in the list.
 652
 653         sw_tbl :: Array Int SwitchResult
 654         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 655                         all_undefined)
 656                  // defined_elems
 657
 658         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 659
 660         defined_elems = map mk_assoc_elem tidied_on_switches
 661     in
 662     -- (avoid some unboxing, bounds checking, and other horrible things:)
 663 #if __GLASGOW_HASKELL__ < 405
 664     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 665 #else
 666     case sw_tbl of { Array _ _ stuff ->
 667 #endif
 668     \ switch ->
 669         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 670 #if __GLASGOW_HASKELL__ < 400
 671           Lift v -> v
 672 #elif __GLASGOW_HASKELL__ < 403
 673           (# _, v #) -> v
 674 #else
 675           (# v #) -> v
 676 #endif
 677     }
 678   where
 679     mk_assoc_elem k@(MaxSimplifierIterations lvl)
 680         = (iBox (tagOf_SimplSwitch k), SwInt lvl)
 681     mk_assoc_elem k@(SimplInlinePhase n)
 682         = (iBox (tagOf_SimplSwitch k), SwInt n)
 683     mk_assoc_elem k
 684         = (iBox (tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 685
 686     -- cannot have duplicates if we are going to use the array thing
 687     rm_dups switches_so_far switch
 688       = if switch `is_elem` switches_so_far
 689         then switches_so_far
 690         else switch : switches_so_far
 691       where
 692         sw `is_elem` []     = False
 693         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) ==# (tagOf_SimplSwitch s)
 694                             || sw `is_elem` ss
 695 \end{code}
 696
 697
 698 %************************************************************************
 699 %*                                                                      *
 700 \subsection{Misc functions for command-line options}
 701 %*                                                                      *
 702 %************************************************************************
 703
 704
 705 \begin{code}
 706 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 707
 708 switchIsOn lookup_fn switch
 709   = case (lookup_fn switch) of
 710       SwBool False -> False
 711       _            -> True
 712
 713 intSwitchSet :: (switch -> SwitchResult)
 714              -> (Int -> switch)
 715              -> Maybe Int
 716
 717 intSwitchSet lookup_fn switch
 718   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 719       SwInt int -> Just int
 720       _         -> Nothing
 721 \end{code}
 722
 723 \begin{code}
 724 startsWith :: String -> String -> Maybe String
 725 -- startsWith pfx (pfx++rest) = Just rest
 726
 727 startsWith []     str = Just str
 728 startsWith (c:cs) (s:ss)
 729   = if c /= s then Nothing else startsWith cs ss
 730 startsWith  _     []  = Nothing
 731
 732 endsWith  :: String -> String -> Maybe String
 733 endsWith cs ss
 734   = case (startsWith (reverse cs) (reverse ss)) of
 735       Nothing -> Nothing
 736       Just rs -> Just (reverse rs)
 737 \end{code}