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