ghc/compiler/main/CmdLineOpts.lhs

   1 %
   2 % (c) The AQUA Project, Glasgow University, 1996-98
   3 %
   4 \section[CmdLineOpts]{Things to do with command-line options}
   5
   6 \begin{code}
   7 module CmdLineOpts (
   8         CoreToDo(..),
   9         SimplifierSwitch(..),
  10         StgToDo(..),
  11         SwitchResult(..),
  12         classifyOpts,
  13
  14         intSwitchSet,
  15         switchIsOn,
  16
  17         opt_AllStrict,
  18         opt_AllowOverlappingInstances,
  19         opt_AllowUndecidableInstances,
  20         opt_AutoSccsOnAllToplevs,
  21         opt_AutoSccsOnExportedToplevs,
  22         opt_AutoSccsOnIndividualCafs,
  23         opt_D_dump_absC,
  24         opt_D_dump_asm,
  25         opt_D_dump_deriv,
  26         opt_D_dump_ds,
  27         opt_D_dump_flatC,
  28         opt_D_dump_inlinings,
  29         opt_D_dump_foreign,
  30         opt_D_dump_occur_anal,
  31         opt_D_dump_rdr,
  32         opt_D_dump_realC,
  33         opt_D_dump_rn,
  34         opt_D_dump_simpl,
  35         opt_D_dump_simpl_iterations,
  36         opt_D_dump_spec,
  37         opt_D_dump_stg,
  38         opt_D_dump_stranal,
  39         opt_D_dump_tc,
  40         opt_D_show_passes,
  41         opt_D_show_rn_trace,
  42         opt_D_show_rn_imports,
  43         opt_D_simplifier_stats,
  44         opt_D_source_stats,
  45         opt_D_verbose_core2core,
  46         opt_D_verbose_stg2stg,
  47         opt_DictsStrict,
  48         opt_DoCoreLinting,
  49         opt_DoStgLinting,
  50         opt_DoSemiTagging,
  51         opt_DoEtaReduction,
  52         opt_DoTickyProfiling,
  53         opt_EmitCExternDecls,
  54         opt_EnsureSplittableC,
  55         opt_FoldrBuildOn,
  56         opt_GlasgowExts,
  57         opt_GranMacros,
  58         opt_HiMap,
  59         opt_HiVersion,
  60         opt_IgnoreIfacePragmas,
  61         opt_IrrefutableTuples,
  62         opt_LiberateCaseThreshold,
  63         opt_MaxContextReductionDepth,
  64         opt_MultiParamClasses,
  65         opt_NoHiCheck,
  66         opt_NoImplicitPrelude,
  67         opt_NoPreInlining,
  68         opt_NumbersStrict,
  69         opt_OmitBlackHoling,
  70         opt_OmitInterfacePragmas,
  71         opt_PprStyle_NoPrags,
  72         opt_PprStyle_Debug,
  73         opt_PprUserLength,
  74         opt_ProduceC,
  75         opt_ProduceHi,
  76         opt_ProduceS,
  77         opt_ProduceExportCStubs,
  78         opt_ProduceExportHStubs,
  79         opt_ReportCompile,
  80         opt_SccGroup,
  81         opt_SccProfilingOn,
  82         opt_SourceUnchanged,
  83         opt_Static,
  84         opt_StgDoLetNoEscapes,
  85         opt_Parallel,
  86
  87         opt_InterfaceUnfoldThreshold,
  88         opt_UnfoldCasms,
  89         opt_UnfoldingCreationThreshold,
  90         opt_UnfoldingConDiscount,
  91         opt_UnfoldingUseThreshold,
  92         opt_UnfoldingKeenessFactor,
  93
  94         opt_Verbose,
  95
  96         opt_WarnNameShadowing,
  97         opt_WarnUnusedMatches,
  98         opt_WarnUnusedBinds,
  99         opt_WarnUnusedImports,
 100         opt_WarnIncompletePatterns,
 101         opt_WarnOverlappingPatterns,
 102         opt_WarnSimplePatterns,
 103         opt_WarnTypeDefaults,
 104         opt_WarnMissingMethods,
 105         opt_WarnDuplicateExports,
 106         opt_WarnHiShadows,
 107         opt_WarnMissingSigs,
 108         opt_PruneTyDecls, opt_PruneInstDecls,
 109         opt_D_show_rn_stats
 110     ) where
 111
 112 #include "HsVersions.h"
 113
 114 import Array    ( array, (//) )
 115 import GlaExts
 116 import Argv
 117 import Constants        -- Default values for some flags
 118
 119 import Maybes           ( assocMaybe, firstJust, maybeToBool )
 120 import Panic            ( panic, panic# )
 121
 122 #if __GLASGOW_HASKELL__ < 301
 123 import ArrBase  ( Array(..) )
 124 #else
 125 import PrelArr  ( Array(..) )
 126 #endif
 127 \end{code}
 128
 129 A command-line {\em switch} is (generally) either on or off; e.g., the
 130 ``verbose'' (-v) switch is either on or off.  (The \tr{-G<group>}
 131 switch is an exception; it's set to a string, or nothing.)
 132
 133 A list of {\em ToDo}s is things to be done in a particular part of
 134 processing.  A (fictitious) example for the Core-to-Core simplifier
 135 might be: run the simplifier, then run the strictness analyser, then
 136 run the simplifier again (three ``todos'').
 137
 138 There are three ``to-do processing centers'' at the moment.  In the
 139 main loop (\tr{main/Main.lhs}), in the Core-to-Core processing loop
 140 (\tr{simplCore/SimplCore.lhs), and in the STG-to-STG processing loop
 141 (\tr{simplStg/SimplStg.lhs}).
 142
 143 %************************************************************************
 144 %*                                                                      *
 145 \subsection{Datatypes associated with command-line options}
 146 %*                                                                      *
 147 %************************************************************************
 148
 149 \begin{code}
 150 data SwitchResult
 151   = SwBool      Bool            -- on/off
 152   | SwString    FAST_STRING     -- nothing or a String
 153   | SwInt       Int             -- nothing or an Int
 154 \end{code}
 155
 156 \begin{code}
 157 data CoreToDo           -- These are diff core-to-core passes,
 158                         -- which may be invoked in any order,
 159                         -- as many times as you like.
 160
 161   = CoreDoSimplify      -- The core-to-core simplifier.
 162         (SimplifierSwitch -> SwitchResult)
 163                         -- Each run of the simplifier can take a different
 164                         -- set of simplifier-specific flags.
 165   | CoreDoCalcInlinings1
 166   | CoreDoCalcInlinings2
 167   | CoreDoFloatInwards
 168   | CoreDoFullLaziness
 169   | CoreLiberateCase
 170   | CoreDoPrintCore
 171   | CoreDoStaticArgs
 172   | CoreDoStrictness
 173   | CoreDoSpecialising
 174   | CoreDoFoldrBuildWorkerWrapper
 175   | CoreDoFoldrBuildWWAnal
 176 \end{code}
 177
 178 \begin{code}
 179 data StgToDo
 180   = StgDoStaticArgs
 181   | StgDoUpdateAnalysis
 182   | StgDoLambdaLift
 183   | StgDoMassageForProfiling  -- should be (next to) last
 184   -- There's also setStgVarInfo, but its absolute "lastness"
 185   -- is so critical that it is hardwired in (no flag).
 186   | D_stg_stats
 187 \end{code}
 188
 189 \begin{code}
 190 data SimplifierSwitch
 191   = SimplOkToDupCode
 192   | SimplFloatLetsExposingWHNF
 193   | SimplOkToFloatPrimOps
 194   | SimplAlwaysFloatLetsFromLets
 195   | SimplDoCaseElim
 196   | SimplCaseOfCase
 197   | SimplLetToCase
 198   | SimplMayDeleteConjurableIds
 199   | SimplPedanticBottoms -- see Simplifier for an explanation
 200   | SimplDoArityExpand   -- expand arity of bindings
 201   | SimplDoFoldrBuild    -- This is the per-simplification flag;
 202                          -- see also FoldrBuildOn, used elsewhere
 203                          -- in the compiler.
 204   | SimplDoInlineFoldrBuild
 205                          -- inline foldr/build (*after* f/b rule is used)
 206
 207   | IgnoreINLINEPragma
 208   | SimplDoLambdaEtaExpansion
 209
 210   | EssentialUnfoldingsOnly -- never mind the thresholds, only
 211                             -- do unfoldings that *must* be done
 212                             -- (to saturate constructors and primitives)
 213
 214   | MaxSimplifierIterations Int
 215
 216   | SimplNoLetFromCase      -- used when turning off floating entirely
 217   | SimplNoLetFromApp       -- (for experimentation only) WDP 95/10
 218   | SimplNoLetFromStrictLet
 219
 220   | SimplCaseMerge
 221   | SimplPleaseClone
 222 \end{code}
 223
 224 %************************************************************************
 225 %*                                                                      *
 226 \subsection{Classifying command-line options}
 227 %*                                                                      *
 228 %************************************************************************
 229
 230 \begin{code}
 231 lookUp           :: FAST_STRING -> Bool
 232 lookup_int       :: String -> Maybe Int
 233 lookup_def_int   :: String -> Int -> Int
 234 lookup_def_float :: String -> Float -> Float
 235 lookup_str       :: String -> Maybe String
 236
 237 lookUp     sw = maybeToBool (assoc_opts sw)
 238
 239 lookup_str sw = firstJust (map (startsWith sw) unpacked_opts)
 240
 241 lookup_int sw = case (lookup_str sw) of
 242                   Nothing -> Nothing
 243                   Just xx -> Just (read xx)
 244
 245 lookup_def_int sw def = case (lookup_str sw) of
 246                             Nothing -> def              -- Use default
 247                             Just xx -> read xx
 248
 249 lookup_def_float sw def = case (lookup_str sw) of
 250                             Nothing -> def              -- Use default
 251                             Just xx -> read xx
 252
 253 assoc_opts    = assocMaybe [ (a, True) | a <- argv ]
 254 unpacked_opts = map _UNPK_ argv
 255
 256 {-
 257  Putting the compiler options into temporary at-files
 258  may turn out to be necessary later on if we turn hsc into
 259  a pure Win32 application where I think there's a command-line
 260  length limit of 255. unpacked_opts understands the @ option.
 261
 262 assoc_opts    = assocMaybe [ (_PK_ a, True) | a <- unpacked_opts ]
 263
 264 unpacked_opts :: [String]
 265 unpacked_opts =
 266   concat $
 267   map (expandAts) $
 268   map _UNPK_ argv
 269   where
 270    expandAts ('@':fname) = words (unsafePerformIO (readFile fname))
 271    expandAts l = [l]
 272 -}
 273 \end{code}
 274
 275 \begin{code}
 276 opt_AllStrict                   = lookUp  SLIT("-fall-strict")
 277 opt_AllowOverlappingInstances   = lookUp  SLIT("-fallow-overlapping-instances")
 278 opt_AllowUndecidableInstances   = lookUp  SLIT("-fallow-undecidable-instances")
 279 opt_AutoSccsOnAllToplevs        = lookUp  SLIT("-fauto-sccs-on-all-toplevs")
 280 opt_AutoSccsOnExportedToplevs   = lookUp  SLIT("-fauto-sccs-on-exported-toplevs")
 281 opt_AutoSccsOnIndividualCafs    = lookUp  SLIT("-fauto-sccs-on-individual-cafs")
 282 opt_D_dump_absC                 = lookUp  SLIT("-ddump-absC")
 283 opt_D_dump_asm                  = lookUp  SLIT("-ddump-asm")
 284 opt_D_dump_deriv                = lookUp  SLIT("-ddump-deriv")
 285 opt_D_dump_ds                   = lookUp  SLIT("-ddump-ds")
 286 opt_D_dump_flatC                = lookUp  SLIT("-ddump-flatC")
 287 opt_D_dump_inlinings            = lookUp  SLIT("-ddump-inlinings")
 288 opt_D_dump_foreign              = lookUp  SLIT("-ddump-foreign-stubs")
 289 opt_D_dump_occur_anal           = lookUp  SLIT("-ddump-occur-anal")
 290 opt_D_dump_rdr                  = lookUp  SLIT("-ddump-rdr")
 291 opt_D_dump_realC                = lookUp  SLIT("-ddump-realC")
 292 opt_D_dump_rn                   = lookUp  SLIT("-ddump-rn")
 293 opt_D_dump_simpl                = lookUp  SLIT("-ddump-simpl")
 294 opt_D_dump_simpl_iterations     = lookUp  SLIT("-ddump-simpl-iterations")
 295 opt_D_dump_spec                 = lookUp  SLIT("-ddump-spec")
 296 opt_D_dump_stg                  = lookUp  SLIT("-ddump-stg")
 297 opt_D_dump_stranal              = lookUp  SLIT("-ddump-stranal")
 298 opt_D_dump_tc                   = lookUp  SLIT("-ddump-tc")
 299 opt_D_show_passes               = lookUp  SLIT("-dshow-passes")
 300 opt_D_show_rn_trace             = lookUp  SLIT("-dshow-rn-trace")
 301 opt_D_show_rn_imports           = lookUp  SLIT("-dshow-rn-imports")
 302 opt_D_simplifier_stats          = lookUp  SLIT("-dsimplifier-stats")
 303 opt_D_source_stats              = lookUp  SLIT("-dsource-stats")
 304 opt_D_verbose_core2core         = lookUp  SLIT("-dverbose-simpl")
 305 opt_D_verbose_stg2stg           = lookUp  SLIT("-dverbose-stg")
 306 opt_DictsStrict                 = lookUp  SLIT("-fdicts-strict")
 307 opt_DoCoreLinting               = lookUp  SLIT("-dcore-lint")
 308 opt_DoStgLinting                = lookUp  SLIT("-dstg-lint")
 309 opt_DoEtaReduction              = lookUp  SLIT("-fdo-eta-reduction")
 310 opt_DoSemiTagging               = lookUp  SLIT("-fsemi-tagging")
 311 opt_DoTickyProfiling            = lookUp  SLIT("-fticky-ticky")
 312 opt_EmitCExternDecls            = lookUp  SLIT("-femit-extern-decls")
 313 opt_EnsureSplittableC           = lookUp  SLIT("-fglobalise-toplev-names")
 314 opt_FoldrBuildOn                = lookUp  SLIT("-ffoldr-build-on")
 315 opt_GranMacros                  = lookUp  SLIT("-fgransim")
 316 opt_GlasgowExts                 = lookUp  SLIT("-fglasgow-exts")
 317 opt_HiMap                       = lookup_str "-himap="       -- file saying where to look for .hi files
 318 opt_HiVersion                   = lookup_def_int "-fhi-version=" 0 -- what version we're compiling.
 319 opt_IgnoreIfacePragmas          = lookUp  SLIT("-fignore-interface-pragmas")
 320 opt_IrrefutableTuples           = lookUp  SLIT("-firrefutable-tuples")
 321 opt_MaxContextReductionDepth    = lookup_def_int "-fcontext-stack" mAX_CONTEXT_REDUCTION_DEPTH
 322 opt_MultiParamClasses           = opt_GlasgowExts
 323 opt_NoHiCheck                   = lookUp  SLIT("-fno-hi-version-check")
 324 opt_NoImplicitPrelude           = lookUp  SLIT("-fno-implicit-prelude")
 325 opt_NoPreInlining               = lookUp  SLIT("-fno-pre-inlining")
 326 opt_NumbersStrict               = lookUp  SLIT("-fnumbers-strict")
 327 opt_OmitBlackHoling             = lookUp  SLIT("-dno-black-holing")
 328 opt_OmitInterfacePragmas        = lookUp  SLIT("-fomit-interface-pragmas")
 329 opt_PprStyle_NoPrags            = lookUp  SLIT("-dppr-noprags")
 330 opt_PprStyle_Debug              = lookUp  SLIT("-dppr-debug")
 331 opt_PprUserLength               = lookup_def_int "-dppr-user-length" 5 --ToDo: give this a name
 332 opt_ProduceC                    = lookup_str "-C="
 333 opt_ProduceS                    = lookup_str "-S="
 334 opt_ProduceExportCStubs         = lookup_str "-F="
 335 opt_ProduceExportHStubs         = lookup_str "-FH="
 336 opt_ProduceHi                   = lookup_str "-hifile=" -- the one to produce this time
 337 opt_ReportCompile                = lookUp SLIT("-freport-compile")
 338 opt_SccProfilingOn              = lookUp  SLIT("-fscc-profiling")
 339 opt_SourceUnchanged             = lookUp  SLIT("-fsource-unchanged")
 340 opt_StgDoLetNoEscapes           = lookUp  SLIT("-flet-no-escape")
 341 opt_Parallel                    = lookUp  SLIT("-fparallel")
 342 opt_Static                      = lookUp  SLIT("-static")
 343 opt_SccGroup                    = lookup_str "-G="
 344 opt_Verbose                     = lookUp  SLIT("-v")
 345
 346 opt_UnfoldCasms                 = lookUp SLIT("-funfold-casms-in-hi-file")
 347 opt_InterfaceUnfoldThreshold    = lookup_def_int "-funfolding-interface-threshold" iNTERFACE_UNFOLD_THRESHOLD
 348 opt_UnfoldingCreationThreshold  = lookup_def_int "-funfolding-creation-threshold"  uNFOLDING_CREATION_THRESHOLD
 349 opt_UnfoldingUseThreshold       = lookup_def_int "-funfolding-use-threshold"       uNFOLDING_USE_THRESHOLD
 350 opt_UnfoldingConDiscount        = lookup_def_int "-funfolding-con-discount"        uNFOLDING_CON_DISCOUNT_WEIGHT
 351
 352 opt_LiberateCaseThreshold       = lookup_def_int "-fliberate-case-threshold"       lIBERATE_CASE_THRESHOLD
 353 opt_UnfoldingKeenessFactor      = lookup_def_float "-funfolding-keeness-factor"    uNFOLDING_KEENESS_FACTOR
 354 opt_WarnNameShadowing           = lookUp  SLIT("-fwarn-name-shadowing")
 355 opt_WarnHiShadows               = lookUp  SLIT("-fwarn-hi-shadowing")
 356 opt_WarnIncompletePatterns      = lookUp  SLIT("-fwarn-incomplete-patterns")
 357 opt_WarnOverlappingPatterns     = lookUp  SLIT("-fwarn-overlapping-patterns")
 358 opt_WarnSimplePatterns          = lookUp  SLIT("-fwarn-simple-patterns")
 359 opt_WarnTypeDefaults            = lookUp  SLIT("-fwarn-type-defaults")
 360 opt_WarnUnusedMatches           = lookUp  SLIT("-fwarn-unused-matches")
 361 opt_WarnUnusedBinds             = lookUp  SLIT("-fwarn-unused-binds")
 362 opt_WarnUnusedImports           = lookUp  SLIT("-fwarn-unused-imports")
 363 opt_WarnMissingMethods          = lookUp  SLIT("-fwarn-missing-methods")
 364 opt_WarnDuplicateExports        = lookUp  SLIT("-fwarn-duplicate-exports")
 365 opt_WarnMissingSigs             = lookUp  SLIT("-fwarn-missing-signatures")
 366 opt_PruneTyDecls                = not (lookUp SLIT("-fno-prune-tydecls"))
 367 opt_PruneInstDecls              = not (lookUp SLIT("-fno-prune-instdecls"))
 368 opt_D_show_rn_stats             = lookUp SLIT("-dshow-rn-stats")
 369
 370 -- opt_UnfoldingOverrideThreshold       = lookup_int "-funfolding-override-threshold"
 371 \end{code}
 372
 373 \begin{code}
 374 classifyOpts :: ([CoreToDo],    -- Core-to-Core processing spec
 375                  [StgToDo])     -- STG-to-STG   processing spec
 376
 377 classifyOpts = sep argv [] [] -- accumulators...
 378   where
 379     sep :: [FAST_STRING]                 -- cmd-line opts (input)
 380         -> [CoreToDo] -> [StgToDo]       -- to_do accumulators
 381         -> ([CoreToDo], [StgToDo])       -- result
 382
 383     sep [] core_td stg_td -- all done!
 384       = (reverse core_td, reverse stg_td)
 385
 386 #       define CORE_TD(to_do) sep opts (to_do:core_td) stg_td
 387 #       define STG_TD(to_do)  sep opts core_td (to_do:stg_td)
 388
 389     sep (opt1:opts) core_td stg_td
 390       = case (_UNPK_ opt1) of -- the non-"just match a string" options are at the end...
 391           ',' : _       -> sep opts core_td stg_td -- it is for the parser
 392
 393           "-fsimplify"  -> -- gather up SimplifierSwitches specially...
 394                            simpl_sep opts defaultSimplSwitches core_td stg_td
 395
 396           "-fcalc-inlinings1"-> CORE_TD(CoreDoCalcInlinings1)
 397           "-fcalc-inlinings2"-> CORE_TD(CoreDoCalcInlinings2)
 398           "-ffloat-inwards"  -> CORE_TD(CoreDoFloatInwards)
 399           "-ffull-laziness"  -> CORE_TD(CoreDoFullLaziness)
 400           "-fliberate-case"  -> CORE_TD(CoreLiberateCase)
 401           "-fprint-core"     -> CORE_TD(CoreDoPrintCore)
 402           "-fstatic-args"    -> CORE_TD(CoreDoStaticArgs)
 403           "-fstrictness"     -> CORE_TD(CoreDoStrictness)
 404           "-fspecialise"     -> CORE_TD(CoreDoSpecialising)
 405           "-ffoldr-build-worker-wrapper"  -> CORE_TD(CoreDoFoldrBuildWorkerWrapper)
 406           "-ffoldr-build-ww-anal"  -> CORE_TD(CoreDoFoldrBuildWWAnal)
 407
 408           "-fstg-static-args" -> STG_TD(StgDoStaticArgs)
 409           "-fupdate-analysis" -> STG_TD(StgDoUpdateAnalysis)
 410           "-dstg-stats"       -> STG_TD(D_stg_stats)
 411           "-flambda-lift"     -> STG_TD(StgDoLambdaLift)
 412           "-fmassage-stg-for-profiling" -> STG_TD(StgDoMassageForProfiling)
 413
 414           _ -> -- NB: the driver is really supposed to handle bad options
 415                sep opts core_td stg_td
 416
 417     ----------------
 418
 419     simpl_sep :: [FAST_STRING]            -- cmd-line opts (input)
 420               -> [SimplifierSwitch]       -- simplifier-switch accumulator
 421               -> [CoreToDo] -> [StgToDo]  -- to_do accumulators
 422               -> ([CoreToDo], [StgToDo])  -- result
 423
 424         -- "simpl_sep" tailcalls "sep" once it's seen one set
 425         -- of SimplifierSwitches for a CoreDoSimplify.
 426
 427 #ifdef DEBUG
 428     simpl_sep input@[] simpl_sw core_td stg_td
 429       = panic "simpl_sep []"
 430 #endif
 431
 432         -- The SimplifierSwitches should be delimited by "[" and "]".
 433
 434     simpl_sep (opt1:opts) simpl_sw core_td stg_td
 435       = case (_UNPK_ opt1) of
 436           "[" -> simpl_sep opts simpl_sw core_td stg_td
 437           "]" -> let
 438                     this_simpl = CoreDoSimplify (isAmongSimpl simpl_sw)
 439                  in
 440                  sep opts (this_simpl : core_td) stg_td
 441
 442 #         define SIMPL_SW(sw) simpl_sep opts (sw:simpl_sw) core_td stg_td
 443
 444           -- the non-"just match a string" options are at the end...
 445           "-fcode-duplication-ok"           -> SIMPL_SW(SimplOkToDupCode)
 446           "-ffloat-lets-exposing-whnf"      -> SIMPL_SW(SimplFloatLetsExposingWHNF)
 447           "-ffloat-primops-ok"              -> SIMPL_SW(SimplOkToFloatPrimOps)
 448           "-falways-float-lets-from-lets"   -> SIMPL_SW(SimplAlwaysFloatLetsFromLets)
 449           "-fdo-case-elim"                  -> SIMPL_SW(SimplDoCaseElim)
 450           "-fdo-lambda-eta-expansion"       -> SIMPL_SW(SimplDoLambdaEtaExpansion)
 451           "-fdo-foldr-build"                -> SIMPL_SW(SimplDoFoldrBuild)
 452           "-fdo-arity-expand"               -> SIMPL_SW(SimplDoArityExpand)
 453           "-fdo-inline-foldr-build"         -> SIMPL_SW(SimplDoInlineFoldrBuild)
 454           "-fcase-of-case"                  -> SIMPL_SW(SimplCaseOfCase)
 455           "-fcase-merge"                    -> SIMPL_SW(SimplCaseMerge)
 456           "-flet-to-case"                   -> SIMPL_SW(SimplLetToCase)
 457           "-fpedantic-bottoms"              -> SIMPL_SW(SimplPedanticBottoms)
 458           "-fmay-delete-conjurable-ids"     -> SIMPL_SW(SimplMayDeleteConjurableIds)
 459           "-fessential-unfoldings-only"     -> SIMPL_SW(EssentialUnfoldingsOnly)
 460           "-fignore-inline-pragma"          -> SIMPL_SW(IgnoreINLINEPragma)
 461           "-fno-let-from-case"              -> SIMPL_SW(SimplNoLetFromCase)
 462           "-fno-let-from-app"               -> SIMPL_SW(SimplNoLetFromApp)
 463           "-fno-let-from-strict-let"        -> SIMPL_SW(SimplNoLetFromStrictLet)
 464           "-fclone-binds"                   -> SIMPL_SW(SimplPleaseClone)
 465
 466           o | starts_with_msi  -> SIMPL_SW(MaxSimplifierIterations (read after_msi))
 467            where
 468             maybe_msi           = startsWith "-fmax-simplifier-iterations"   o
 469             starts_with_msi     = maybeToBool maybe_msi
 470             (Just after_msi)    = maybe_msi
 471
 472           _ -> -- NB: the driver is really supposed to handle bad options
 473                simpl_sep opts simpl_sw core_td stg_td
 474 \end{code}
 475
 476 %************************************************************************
 477 %*                                                                      *
 478 \subsection{Switch ordering}
 479 %*                                                                      *
 480 %************************************************************************
 481
 482 In spite of the @Produce*@ and @SccGroup@ constructors, these things
 483 behave just like enumeration types.
 484
 485 \begin{code}
 486 instance Eq SimplifierSwitch where
 487     a == b = tagOf_SimplSwitch a _EQ_ tagOf_SimplSwitch b
 488
 489 instance Ord SimplifierSwitch where
 490     a <  b  = tagOf_SimplSwitch a _LT_ tagOf_SimplSwitch b
 491     a <= b  = tagOf_SimplSwitch a _LE_ tagOf_SimplSwitch b
 492
 493 tagOf_SimplSwitch SimplOkToDupCode              =(ILIT(0) :: FAST_INT)
 494 tagOf_SimplSwitch SimplFloatLetsExposingWHNF    = ILIT(1)
 495 tagOf_SimplSwitch SimplOkToFloatPrimOps         = ILIT(2)
 496 tagOf_SimplSwitch SimplAlwaysFloatLetsFromLets  = ILIT(3)
 497 tagOf_SimplSwitch SimplDoCaseElim               = ILIT(4)
 498 tagOf_SimplSwitch SimplCaseOfCase               = ILIT(6)
 499 tagOf_SimplSwitch SimplLetToCase                = ILIT(7)
 500 tagOf_SimplSwitch SimplMayDeleteConjurableIds   = ILIT(9)
 501 tagOf_SimplSwitch SimplPedanticBottoms          = ILIT(10)
 502 tagOf_SimplSwitch SimplDoArityExpand            = ILIT(11)
 503 tagOf_SimplSwitch SimplDoFoldrBuild             = ILIT(12)
 504 tagOf_SimplSwitch SimplDoInlineFoldrBuild       = ILIT(14)
 505 tagOf_SimplSwitch IgnoreINLINEPragma            = ILIT(15)
 506 tagOf_SimplSwitch SimplDoLambdaEtaExpansion     = ILIT(16)
 507 tagOf_SimplSwitch EssentialUnfoldingsOnly       = ILIT(19)
 508 tagOf_SimplSwitch (MaxSimplifierIterations _)   = ILIT(21)
 509 tagOf_SimplSwitch SimplNoLetFromCase            = ILIT(27)
 510 tagOf_SimplSwitch SimplNoLetFromApp             = ILIT(28)
 511 tagOf_SimplSwitch SimplNoLetFromStrictLet       = ILIT(29)
 512 tagOf_SimplSwitch SimplCaseMerge                = ILIT(31)
 513 tagOf_SimplSwitch SimplPleaseClone              = ILIT(32)
 514
 515 -- If you add anything here, be sure to change lAST_SIMPL_SWITCH_TAG, too!
 516
 517 tagOf_SimplSwitch _ = panic# "tagOf_SimplSwitch"
 518
 519 lAST_SIMPL_SWITCH_TAG = IBOX(tagOf_SimplSwitch SimplPleaseClone)
 520 \end{code}
 521
 522 %************************************************************************
 523 %*                                                                      *
 524 \subsection{Switch lookup}
 525 %*                                                                      *
 526 %************************************************************************
 527
 528 \begin{code}
 529 isAmongSimpl :: [SimplifierSwitch] -> SimplifierSwitch -> SwitchResult
 530
 531 isAmongSimpl on_switches                -- Switches mentioned later occur *earlier*
 532                                         -- in the list; defaults right at the end.
 533   = let
 534         tidied_on_switches = foldl rm_dups [] on_switches
 535                 -- The fold*l* ensures that we keep the latest switches;
 536                 -- ie the ones that occur earliest in the list.
 537
 538         sw_tbl :: Array Int SwitchResult
 539
 540         sw_tbl = (array (0, lAST_SIMPL_SWITCH_TAG) -- bounds...
 541                         all_undefined)
 542                  // defined_elems
 543
 544         all_undefined = [ (i, SwBool False) | i <- [0 .. lAST_SIMPL_SWITCH_TAG ] ]
 545
 546         defined_elems = map mk_assoc_elem tidied_on_switches
 547     in
 548     -- (avoid some unboxing, bounds checking, and other horrible things:)
 549     case sw_tbl of { Array bounds_who_needs_'em stuff ->
 550     \ switch ->
 551         case (indexArray# stuff (tagOf_SimplSwitch switch)) of
 552 #if __GLASGOW_HASKELL__ < 400
 553           Lift v -> v
 554 #else
 555           (# _, v #) -> v
 556 #endif
 557     }
 558   where
 559     mk_assoc_elem k@(MaxSimplifierIterations lvl)       = (IBOX(tagOf_SimplSwitch k), SwInt lvl)
 560
 561     mk_assoc_elem k = (IBOX(tagOf_SimplSwitch k), SwBool True) -- I'm here, Mom!
 562
 563     -- cannot have duplicates if we are going to use the array thing
 564     rm_dups switches_so_far switch
 565       = if switch `is_elem` switches_so_far
 566         then switches_so_far
 567         else switch : switches_so_far
 568       where
 569         sw `is_elem` []     = False
 570         sw `is_elem` (s:ss) = (tagOf_SimplSwitch sw) _EQ_ (tagOf_SimplSwitch s)
 571                             || sw `is_elem` ss
 572 \end{code}
 573
 574 Default settings for simplifier switches
 575
 576 \begin{code}
 577 defaultSimplSwitches = [MaxSimplifierIterations         1
 578                        ]
 579 \end{code}
 580
 581 %************************************************************************
 582 %*                                                                      *
 583 \subsection{Misc functions for command-line options}
 584 %*                                                                      *
 585 %************************************************************************
 586
 587
 588 \begin{code}
 589 switchIsOn :: (switch -> SwitchResult) -> switch -> Bool
 590
 591 switchIsOn lookup_fn switch
 592   = case (lookup_fn switch) of
 593       SwBool False -> False
 594       _            -> True
 595
 596 intSwitchSet :: (switch -> SwitchResult)
 597              -> (Int -> switch)
 598              -> Maybe Int
 599
 600 intSwitchSet lookup_fn switch
 601   = case (lookup_fn (switch (panic "intSwitchSet"))) of
 602       SwInt int -> Just int
 603       _         -> Nothing
 604 \end{code}
 605
 606 \begin{code}
 607 startsWith, endsWith :: String -> String -> Maybe String
 608
 609 startsWith []     str = Just str
 610 startsWith (c:cs) (s:ss)
 611   = if c /= s then Nothing else startsWith cs ss
 612 startsWith  _     []  = Nothing
 613
 614 endsWith cs ss
 615   = case (startsWith (reverse cs) (reverse ss)) of
 616       Nothing -> Nothing
 617       Just rs -> Just (reverse rs)
 618 \end{code}