DynFlags.hs

-------------------------------------------------------------------------------
--
-- | Dynamic flags
--
-- Most flags are dynamic flags, which means they can change from compilation
-- to compilation using @OPTIONS_GHC@ pragmas, and in a multi-session GHC each
-- session can be using different dynamic flags. Dynamic flags can also be set
-- at the prompt in GHCi.
--
-- (c) The University of Glasgow 2005
--
-------------------------------------------------------------------------------

{-# OPTIONS -fno-cse #-}
-- -fno-cse is needed for GLOBAL_VAR's to behave properly

module DynFlags (
        -- * Dynamic flags and associated configuration types
        DumpFlag(..),
        GeneralFlag(..),
        WarningFlag(..),
        ExtensionFlag(..),
        Language(..),
        PlatformConstants(..),
        FatalMessager, LogAction, FlushOut(..), FlushErr(..),
        ProfAuto(..),
        glasgowExtsFlags,
        dopt, dopt_set, dopt_unset,
        gopt, gopt_set, gopt_unset,
        wopt, wopt_set, wopt_unset,
        xopt, xopt_set, xopt_unset,
        lang_set,
        whenGeneratingDynamicToo, ifGeneratingDynamicToo,
        whenCannotGenerateDynamicToo,
        dynamicTooMkDynamicDynFlags,
        DynFlags(..),
        HasDynFlags(..), ContainsDynFlags(..),
        RtsOptsEnabled(..),
        HscTarget(..), isObjectTarget, defaultObjectTarget,
        targetRetainsAllBindings,
        GhcMode(..), isOneShot,
        GhcLink(..), isNoLink,
        PackageFlag(..),
        PkgConfRef(..),
        Option(..), showOpt,
        DynLibLoader(..),
        fFlags, fWarningFlags, fLangFlags, xFlags,
        dynFlagDependencies,
        tablesNextToCode, mkTablesNextToCode,

        printOutputForUser, printInfoForUser,

        Way(..), mkBuildTag, wayRTSOnly, addWay', updateWays,
        wayGeneralFlags, wayUnsetGeneralFlags,

        -- ** Safe Haskell
        SafeHaskellMode(..),
        safeHaskellOn, safeImportsOn, safeLanguageOn, safeInferOn,
        packageTrustOn,
        safeDirectImpsReq, safeImplicitImpsReq,
        unsafeFlags,

        -- ** System tool settings and locations
        Settings(..),
        targetPlatform,
        ghcUsagePath, ghciUsagePath, topDir, tmpDir, rawSettings,
        extraGccViaCFlags, systemPackageConfig,
        pgm_L, pgm_P, pgm_F, pgm_c, pgm_s, pgm_a, pgm_l, pgm_dll, pgm_T,
        pgm_sysman, pgm_windres, pgm_lo, pgm_lc,
        opt_L, opt_P, opt_F, opt_c, opt_a, opt_l,
        opt_windres, opt_lo, opt_lc,


        -- ** Manipulating DynFlags
        defaultDynFlags,                -- Settings -> DynFlags
        defaultWays,
        interpWays,
        initDynFlags,                   -- DynFlags -> IO DynFlags
        defaultFatalMessager,
        defaultLogAction,
        defaultLogActionHPrintDoc,
        defaultLogActionHPutStrDoc,
        defaultFlushOut,
        defaultFlushErr,

        getOpts,                        -- DynFlags -> (DynFlags -> [a]) -> [a]
        getVerbFlags,
        updOptLevel,
        setTmpDir,
        setPackageName,

        -- ** Parsing DynFlags
        parseDynamicFlagsCmdLine,
        parseDynamicFilePragma,
        parseDynamicFlagsFull,

        -- ** Available DynFlags
        allFlags,
        flagsAll,
        flagsDynamic,
        flagsPackage,

        supportedLanguagesAndExtensions,

        -- ** DynFlags C compiler options
        picCCOpts, picPOpts,

        -- * Configuration of the stg-to-stg passes
        StgToDo(..),
        getStgToDo,

        -- * Compiler configuration suitable for display to the user
        compilerInfo,

#ifdef GHCI
-- Only in stage 2 can we be sure that the RTS
-- exposes the appropriate runtime boolean
        rtsIsProfiled,
#endif

#include "../includes/dist-derivedconstants/header/GHCConstantsHaskellExports.hs"
        bLOCK_SIZE_W,
        wORD_SIZE_IN_BITS,
        tAG_MASK,
        mAX_PTR_TAG,
        tARGET_MIN_INT, tARGET_MAX_INT, tARGET_MAX_WORD,

        unsafeGlobalDynFlags, setUnsafeGlobalDynFlags,

        -- * SSE
        isSse2Enabled,
        isSse4_2Enabled,

        -- * Linker information
        LinkerInfo(..),
  ) where

#include "HsVersions.h"

import Platform
import PlatformConstants
import Module
import PackageConfig
import {-# SOURCE #-} PrelNames ( mAIN )
import {-# SOURCE #-} Packages (PackageState)
import DriverPhases     ( Phase(..), phaseInputExt )
import Config
import CmdLineParser
import Constants
import Panic
import Util
import Maybes           ( orElse )
import MonadUtils
import qualified Pretty
import SrcLoc
import FastString
import Outputable
#ifdef GHCI
import Foreign.C        ( CInt(..) )
#endif
import {-# SOURCE #-} ErrUtils ( Severity(..), MsgDoc, mkLocMessage )

import System.IO.Unsafe ( unsafePerformIO )
import Data.IORef
import Control.Monad

import Data.Bits
import Data.Char
import Data.Int
import Data.List
import Data.Map (Map)
import qualified Data.Map as Map
import Data.Maybe
import Data.Set (Set)
import qualified Data.Set as Set
import Data.Word
import System.FilePath
import System.IO
import System.IO.Error

import Data.IntSet (IntSet)
import qualified Data.IntSet as IntSet

import GHC.Foreign (withCString, peekCString)

-- -----------------------------------------------------------------------------
-- DynFlags

data DumpFlag

   -- debugging flags
   = Opt_D_dump_cmm
   | Opt_D_dump_cmm_raw
   -- All of the cmm subflags (there are a lot!)  Automatically
   -- enabled if you run -ddump-cmm
   | Opt_D_dump_cmm_cfg
   | Opt_D_dump_cmm_cbe
   | Opt_D_dump_cmm_proc
   | Opt_D_dump_cmm_rewrite
   | Opt_D_dump_cmm_sp
   | Opt_D_dump_cmm_procmap
   | Opt_D_dump_cmm_split
   | Opt_D_dump_cmm_info
   | Opt_D_dump_cmm_cps
   -- end cmm subflags
   | Opt_D_dump_asm
   | Opt_D_dump_asm_native
   | Opt_D_dump_asm_liveness
   | Opt_D_dump_asm_regalloc
   | Opt_D_dump_asm_regalloc_stages
   | Opt_D_dump_asm_conflicts
   | Opt_D_dump_asm_stats
   | Opt_D_dump_asm_expanded
   | Opt_D_dump_llvm
   | Opt_D_dump_core_stats
   | Opt_D_dump_deriv
   | Opt_D_dump_ds
   | Opt_D_dump_foreign
   | Opt_D_dump_inlinings
   | Opt_D_dump_rule_firings
   | Opt_D_dump_rule_rewrites
   | Opt_D_dump_simpl_trace
   | Opt_D_dump_occur_anal
   | Opt_D_dump_parsed
   | Opt_D_dump_rn
   | Opt_D_dump_core_pipeline -- TODO FIXME: dump after simplifier stats
   | Opt_D_dump_simpl
   | Opt_D_dump_simpl_iterations
   | Opt_D_dump_simpl_phases
   | Opt_D_dump_spec
   | Opt_D_dump_prep
   | Opt_D_dump_stg
   | Opt_D_dump_stranal
   | Opt_D_dump_tc
   | Opt_D_dump_types
   | Opt_D_dump_rules
   | Opt_D_dump_cse
   | Opt_D_dump_worker_wrapper
   | Opt_D_dump_rn_trace
   | Opt_D_dump_rn_stats
   | Opt_D_dump_opt_cmm
   | Opt_D_dump_simpl_stats
   | Opt_D_dump_cs_trace -- Constraint solver in type checker
   | Opt_D_dump_tc_trace
   | Opt_D_dump_if_trace
   | Opt_D_dump_vt_trace
   | Opt_D_dump_splices
   | Opt_D_dump_BCOs
   | Opt_D_dump_vect
   | Opt_D_dump_ticked
   | Opt_D_dump_rtti
   | Opt_D_source_stats
   | Opt_D_verbose_stg2stg
   | Opt_D_dump_hi
   | Opt_D_dump_hi_diffs
   | Opt_D_dump_mod_cycles
   | Opt_D_dump_view_pattern_commoning
   | Opt_D_verbose_core2core

   deriving (Eq, Show, Enum)

-- | Enumerates the simple on-or-off dynamic flags
data GeneralFlag

   = Opt_DumpToFile                     -- ^ Append dump output to files instead of stdout.
   | Opt_D_faststring_stats
   | Opt_D_dump_minimal_imports
   | Opt_DoCoreLinting
   | Opt_DoStgLinting
   | Opt_DoCmmLinting
   | Opt_DoAsmLinting
   | Opt_NoLlvmMangler                 -- hidden flag

   | Opt_WarnIsError                    -- -Werror; makes warnings fatal

   | Opt_PrintExplicitForalls

   -- optimisation opts
   | Opt_Strictness
   | Opt_KillAbsence
   | Opt_KillOneShot
   | Opt_FullLaziness
   | Opt_FloatIn
   | Opt_Specialise
   | Opt_StaticArgumentTransformation
   | Opt_CSE
   | Opt_LiberateCase
   | Opt_SpecConstr
   | Opt_DoLambdaEtaExpansion
   | Opt_IgnoreAsserts
   | Opt_DoEtaReduction
   | Opt_CaseMerge
   | Opt_UnboxStrictFields
   | Opt_UnboxSmallStrictFields
   | Opt_DictsCheap
   | Opt_EnableRewriteRules             -- Apply rewrite rules during simplification
   | Opt_Vectorise
   | Opt_VectorisationAvoidance
   | Opt_RegsGraph                      -- do graph coloring register allocation
   | Opt_RegsIterative                  -- do iterative coalescing graph coloring register allocation
   | Opt_PedanticBottoms                -- Be picky about how we treat bottom
   | Opt_LlvmTBAA                       -- Use LLVM TBAA infastructure for improving AA (hidden flag)
   | Opt_IrrefutableTuples
   | Opt_CmmSink
   | Opt_CmmElimCommonBlocks
   | Opt_OmitYields
   | Opt_SimpleListLiterals
   | Opt_FunToThunk               -- allow WwLib.mkWorkerArgs to remove all value lambdas

   -- Interface files
   | Opt_IgnoreInterfacePragmas
   | Opt_OmitInterfacePragmas
   | Opt_ExposeAllUnfoldings

   -- profiling opts
   | Opt_AutoSccsOnIndividualCafs
   | Opt_ProfCountEntries

   -- misc opts
   | Opt_Pp
   | Opt_ForceRecomp
   | Opt_ExcessPrecision
   | Opt_EagerBlackHoling
   | Opt_NoHsMain
   | Opt_SplitObjs
   | Opt_StgStats
   | Opt_HideAllPackages
   | Opt_PrintBindResult
   | Opt_Haddock
   | Opt_HaddockOptions
   | Opt_Hpc_No_Auto
   | Opt_BreakOnException
   | Opt_BreakOnError
   | Opt_PrintEvldWithShow
   | Opt_PrintBindContents
   | Opt_GenManifest
   | Opt_EmbedManifest
   | Opt_EmitExternalCore
   | Opt_SharedImplib
   | Opt_BuildingCabalPackage
   | Opt_IgnoreDotGhci
   | Opt_GhciSandbox
   | Opt_GhciHistory
   | Opt_HelpfulErrors
   | Opt_DeferTypeErrors
   | Opt_Parallel
   | Opt_GranMacros
   | Opt_PIC
   | Opt_SccProfilingOn
   | Opt_Ticky
   | Opt_Ticky_Allocd
   | Opt_Ticky_LNE
   | Opt_Ticky_Dyn_Thunk
   | Opt_Static
   | Opt_RPath
   | Opt_RelativeDynlibPaths
   | Opt_Hpc
   | Opt_FlatCache

   -- PreInlining is on by default. The option is there just to see how
   -- bad things get if you turn it off!
   | Opt_SimplPreInlining

   -- output style opts
   | Opt_ErrorSpans -- Include full span info in error messages,
                    -- instead of just the start position.
   | Opt_PprCaseAsLet

   -- Suppress all coercions, them replacing with '...'
   | Opt_SuppressCoercions
   | Opt_SuppressVarKinds
   -- Suppress module id prefixes on variables.
   | Opt_SuppressModulePrefixes
   -- Suppress type applications.
   | Opt_SuppressTypeApplications
   -- Suppress info such as arity and unfoldings on identifiers.
   | Opt_SuppressIdInfo
   -- Suppress separate type signatures in core, but leave types on
   -- lambda bound vars
   | Opt_SuppressTypeSignatures
   -- Suppress unique ids on variables.
   -- Except for uniques, as some simplifier phases introduce new
   -- variables that have otherwise identical names.
   | Opt_SuppressUniques

   -- temporary flags
   | Opt_RunCPS
   | Opt_RunCPSZ
   | Opt_AutoLinkPackages
   | Opt_ImplicitImportQualified

   -- keeping stuff
   | Opt_KeepHiDiffs
   | Opt_KeepHcFiles
   | Opt_KeepSFiles
   | Opt_KeepTmpFiles
   | Opt_KeepRawTokenStream
   | Opt_KeepLlvmFiles

   | Opt_BuildDynamicToo

   -- safe haskell flags
   | Opt_DistrustAllPackages
   | Opt_PackageTrust

   deriving (Eq, Show, Enum)

data WarningFlag =
     Opt_WarnDuplicateExports
   | Opt_WarnDuplicateConstraints
   | Opt_WarnHiShadows
   | Opt_WarnImplicitPrelude
   | Opt_WarnIncompletePatterns
   | Opt_WarnIncompleteUniPatterns
   | Opt_WarnIncompletePatternsRecUpd
   | Opt_WarnOverflowedLiterals
   | Opt_WarnEmptyEnumerations
   | Opt_WarnMissingFields
   | Opt_WarnMissingImportList
   | Opt_WarnMissingMethods
   | Opt_WarnMissingSigs
   | Opt_WarnMissingLocalSigs
   | Opt_WarnNameShadowing
   | Opt_WarnOverlappingPatterns
   | Opt_WarnTypeDefaults
   | Opt_WarnMonomorphism
   | Opt_WarnUnusedBinds
   | Opt_WarnUnusedImports
   | Opt_WarnUnusedMatches
   | Opt_WarnWarningsDeprecations
   | Opt_WarnDeprecatedFlags
   | Opt_WarnDodgyExports
   | Opt_WarnDodgyImports
   | Opt_WarnOrphans
   | Opt_WarnAutoOrphans
   | Opt_WarnIdentities
   | Opt_WarnTabs
   | Opt_WarnUnrecognisedPragmas
   | Opt_WarnDodgyForeignImports
   | Opt_WarnLazyUnliftedBindings
   | Opt_WarnUnusedDoBind
   | Opt_WarnWrongDoBind
   | Opt_WarnAlternativeLayoutRuleTransitional
   | Opt_WarnUnsafe
   | Opt_WarnSafe
   | Opt_WarnPointlessPragmas
   | Opt_WarnUnsupportedCallingConventions
   | Opt_WarnUnsupportedLlvmVersion
   | Opt_WarnInlineRuleShadowing
   | Opt_WarnTypeableInstances
   deriving (Eq, Show, Enum)

data Language = Haskell98 | Haskell2010
   deriving Enum

-- | The various Safe Haskell modes
data SafeHaskellMode
   = Sf_None
   | Sf_Unsafe
   | Sf_Trustworthy
   | Sf_Safe
   | Sf_SafeInferred
   deriving (Eq)

instance Show SafeHaskellMode where
    show Sf_None         = "None"
    show Sf_Unsafe       = "Unsafe"
    show Sf_Trustworthy  = "Trustworthy"
    show Sf_Safe         = "Safe"
    show Sf_SafeInferred = "Safe-Inferred"

instance Outputable SafeHaskellMode where
    ppr = text . show

data ExtensionFlag
   = Opt_Cpp
   | Opt_OverlappingInstances
   | Opt_UndecidableInstances
   | Opt_IncoherentInstances
   | Opt_MonomorphismRestriction
   | Opt_MonoPatBinds
   | Opt_MonoLocalBinds
   | Opt_RelaxedPolyRec           -- Deprecated
   | Opt_ExtendedDefaultRules     -- Use GHC's extended rules for defaulting
   | Opt_ForeignFunctionInterface
   | Opt_UnliftedFFITypes
   | Opt_InterruptibleFFI
   | Opt_CApiFFI
   | Opt_GHCForeignImportPrim
   | Opt_ParallelArrays           -- Syntactic support for parallel arrays
   | Opt_Arrows                   -- Arrow-notation syntax
   | Opt_TemplateHaskell
   | Opt_QuasiQuotes
   | Opt_ImplicitParams
   | Opt_ImplicitPrelude
   | Opt_ScopedTypeVariables
   | Opt_AllowAmbiguousTypes
   | Opt_UnboxedTuples
   | Opt_BangPatterns
   | Opt_TypeFamilies
   | Opt_OverloadedStrings
   | Opt_OverloadedLists
   | Opt_DisambiguateRecordFields
   | Opt_RecordWildCards
   | Opt_RecordPuns
   | Opt_ViewPatterns
   | Opt_GADTs
   | Opt_GADTSyntax
   | Opt_NPlusKPatterns
   | Opt_DoAndIfThenElse
   | Opt_RebindableSyntax
   | Opt_ConstraintKinds
   | Opt_PolyKinds                -- Kind polymorphism
   | Opt_DataKinds                -- Datatype promotion
   | Opt_InstanceSigs
 
   | Opt_StandaloneDeriving
   | Opt_DeriveDataTypeable
   | Opt_AutoDeriveTypeable       -- Automatic derivation of Typeable
   | Opt_DeriveFunctor
   | Opt_DeriveTraversable
   | Opt_DeriveFoldable
   | Opt_DeriveGeneric            -- Allow deriving Generic/1
   | Opt_DefaultSignatures        -- Allow extra signatures for defmeths

   | Opt_TypeSynonymInstances
   | Opt_FlexibleContexts
   | Opt_FlexibleInstances
   | Opt_ConstrainedClassMethods
   | Opt_MultiParamTypeClasses
   | Opt_NullaryTypeClasses
   | Opt_FunctionalDependencies
   | Opt_UnicodeSyntax
   | Opt_ExistentialQuantification
   | Opt_MagicHash
   | Opt_EmptyDataDecls
   | Opt_KindSignatures
   | Opt_RoleAnnotations
   | Opt_ParallelListComp
   | Opt_TransformListComp
   | Opt_MonadComprehensions
   | Opt_GeneralizedNewtypeDeriving
   | Opt_RecursiveDo
   | Opt_PostfixOperators
   | Opt_TupleSections
   | Opt_PatternGuards
   | Opt_LiberalTypeSynonyms
   | Opt_RankNTypes
   | Opt_ImpredicativeTypes
   | Opt_TypeOperators
   | Opt_ExplicitNamespaces
   | Opt_PackageImports
   | Opt_ExplicitForAll
   | Opt_AlternativeLayoutRule
   | Opt_AlternativeLayoutRuleTransitional
   | Opt_DatatypeContexts
   | Opt_NondecreasingIndentation
   | Opt_RelaxedLayout
   | Opt_TraditionalRecordSyntax
   | Opt_LambdaCase
   | Opt_MultiWayIf
   | Opt_TypeHoles
   | Opt_NegativeLiterals
   | Opt_EmptyCase
   deriving (Eq, Enum, Show)

-- | Contains not only a collection of 'GeneralFlag's but also a plethora of
-- information relating to the compilation of a single file or GHC session
data DynFlags = DynFlags {
  ghcMode               :: GhcMode,
  ghcLink               :: GhcLink,
  hscTarget             :: HscTarget,
  settings              :: Settings,
  verbosity             :: Int,         -- ^ Verbosity level: see Note [Verbosity levels]
  optLevel              :: Int,         -- ^ Optimisation level
  simplPhases           :: Int,         -- ^ Number of simplifier phases
  maxSimplIterations    :: Int,         -- ^ Max simplifier iterations
  shouldDumpSimplPhase  :: Maybe String,
  ruleCheck             :: Maybe String,
  strictnessBefore      :: [Int],       -- ^ Additional demand analysis

  simplTickFactor       :: Int,         -- ^ Multiplier for simplifier ticks
  specConstrThreshold   :: Maybe Int,   -- ^ Threshold for SpecConstr
  specConstrCount       :: Maybe Int,   -- ^ Max number of specialisations for any one function
  specConstrRecursive   :: Int,         -- ^ Max number of specialisations for recursive types
                                        --   Not optional; otherwise ForceSpecConstr can diverge.
  liberateCaseThreshold :: Maybe Int,   -- ^ Threshold for LiberateCase
  floatLamArgs          :: Maybe Int,   -- ^ Arg count for lambda floating
                                        --   See CoreMonad.FloatOutSwitches
  historySize           :: Int,

  cmdlineHcIncludes     :: [String],    -- ^ @\-\#includes@
  importPaths           :: [FilePath],
  mainModIs             :: Module,
  mainFunIs             :: Maybe String,
  ctxtStkDepth          :: Int,         -- ^ Typechecker context stack depth

  thisPackage           :: PackageId,   -- ^ name of package currently being compiled

  -- ways
  ways                  :: [Way],       -- ^ Way flags from the command line
  buildTag              :: String,      -- ^ The global \"way\" (e.g. \"p\" for prof)
  rtsBuildTag           :: String,      -- ^ The RTS \"way\"

  -- For object splitting
  splitInfo             :: Maybe (String,Int),

  -- paths etc.
  objectDir             :: Maybe String,
  dylibInstallName      :: Maybe String,
  hiDir                 :: Maybe String,
  stubDir               :: Maybe String,
  dumpDir               :: Maybe String,

  objectSuf             :: String,
  hcSuf                 :: String,
  hiSuf                 :: String,

  canGenerateDynamicToo :: IORef Bool,
  dynObjectSuf          :: String,
  dynHiSuf              :: String,

  -- Packages.isDllName needs to know whether a call is within a
  -- single DLL or not. Normally it does this by seeing if the call
  -- is to the same package, but for the ghc package, we split the
  -- package between 2 DLLs. The dllSplit tells us which sets of
  -- modules are in which package.
  dllSplitFile          :: Maybe FilePath,
  dllSplit              :: Maybe [Set String],

  outputFile            :: Maybe String,
  dynOutputFile         :: Maybe String,
  outputHi              :: Maybe String,
  dynLibLoader          :: DynLibLoader,

  -- | This is set by 'DriverPipeline.runPipeline' based on where
  --    its output is going.
  dumpPrefix            :: Maybe FilePath,

  -- | Override the 'dumpPrefix' set by 'DriverPipeline.runPipeline'.
  --    Set by @-ddump-file-prefix@
  dumpPrefixForce       :: Maybe FilePath,

  ldInputs              :: [Option],

  includePaths          :: [String],
  libraryPaths          :: [String],
  frameworkPaths        :: [String],    -- used on darwin only
  cmdlineFrameworks     :: [String],    -- ditto

  rtsOpts               :: Maybe String,
  rtsOptsEnabled        :: RtsOptsEnabled,

  hpcDir                :: String,      -- ^ Path to store the .mix files

  -- Plugins
  pluginModNames        :: [ModuleName],
  pluginModNameOpts     :: [(ModuleName,String)],

  --  For ghc -M
  depMakefile           :: FilePath,
  depIncludePkgDeps     :: Bool,
  depExcludeMods        :: [ModuleName],
  depSuffixes           :: [String],

  --  Package flags
  extraPkgConfs         :: [PkgConfRef] -> [PkgConfRef],
        -- ^ The @-package-db@ flags given on the command line, in the order
        -- they appeared.

  packageFlags          :: [PackageFlag],
        -- ^ The @-package@ and @-hide-package@ flags from the command-line

  -- Package state
  -- NB. do not modify this field, it is calculated by
  -- Packages.initPackages and Packages.updatePackages.
  pkgDatabase           :: Maybe [PackageConfig],
  pkgState              :: PackageState,

  -- Temporary files
  -- These have to be IORefs, because the defaultCleanupHandler needs to
  -- know what to clean when an exception happens
  filesToClean          :: IORef [FilePath],
  dirsToClean           :: IORef (Map FilePath FilePath),
  filesToNotIntermediateClean :: IORef [FilePath],
  -- The next available suffix to uniquely name a temp file, updated atomically
  nextTempSuffix        :: IORef Int,

  -- Names of files which were generated from -ddump-to-file; used to
  -- track which ones we need to truncate because it's our first run
  -- through
  generatedDumps        :: IORef (Set FilePath),

  -- hsc dynamic flags
  dumpFlags             :: IntSet,
  generalFlags          :: IntSet,
  warningFlags          :: IntSet,
  -- Don't change this without updating extensionFlags:
  language              :: Maybe Language,
  -- | Safe Haskell mode
  safeHaskell           :: SafeHaskellMode,
  -- We store the location of where some extension and flags were turned on so
  -- we can produce accurate error messages when Safe Haskell fails due to
  -- them.
  thOnLoc               :: SrcSpan,
  newDerivOnLoc         :: SrcSpan,
  pkgTrustOnLoc         :: SrcSpan,
  warnSafeOnLoc         :: SrcSpan,
  warnUnsafeOnLoc       :: SrcSpan,
  -- Don't change this without updating extensionFlags:
  extensions            :: [OnOff ExtensionFlag],
  -- extensionFlags should always be equal to
  --     flattenExtensionFlags language extensions
  extensionFlags        :: IntSet,

  -- Unfolding control
  -- See Note [Discounts and thresholds] in CoreUnfold
  ufCreationThreshold   :: Int,
  ufUseThreshold        :: Int,
  ufFunAppDiscount      :: Int,
  ufDictDiscount        :: Int,
  ufKeenessFactor       :: Float,
  ufDearOp              :: Int,

  maxWorkerArgs         :: Int,

  ghciHistSize          :: Int,

  -- | MsgDoc output action: use "ErrUtils" instead of this if you can
  log_action            :: LogAction,
  flushOut              :: FlushOut,
  flushErr              :: FlushErr,

  haddockOptions        :: Maybe String,
  ghciScripts           :: [String],

  -- Output style options
  pprUserLength         :: Int,
  pprCols               :: Int,
  traceLevel            :: Int, -- Standard level is 1. Less verbose is 0.

  useUnicodeQuotes      :: Bool,

  -- | what kind of {-# SCC #-} to add automatically
  profAuto              :: ProfAuto,

  interactivePrint      :: Maybe String,

  llvmVersion           :: IORef Int,

  nextWrapperNum        :: IORef Int,

  -- | Machine dependant flags (-m<blah> stuff)
  sseVersion            :: Maybe (Int, Int),  -- (major, minor)

  -- | Run-time linker information (what options we need, etc.)
  rtldFlags             :: IORef (Maybe LinkerInfo)
 }

class HasDynFlags m where
    getDynFlags :: m DynFlags

class ContainsDynFlags t where
    extractDynFlags :: t -> DynFlags
    replaceDynFlags :: t -> DynFlags -> t

data ProfAuto
  = NoProfAuto         -- ^ no SCC annotations added
  | ProfAutoAll        -- ^ top-level and nested functions are annotated
  | ProfAutoTop        -- ^ top-level functions annotated only
  | ProfAutoExports    -- ^ exported functions annotated only
  | ProfAutoCalls      -- ^ annotate call-sites
  deriving (Enum)

data Settings = Settings {
  sTargetPlatform        :: Platform,    -- Filled in by SysTools
  sGhcUsagePath          :: FilePath,    -- Filled in by SysTools
  sGhciUsagePath         :: FilePath,    -- ditto
  sTopDir                :: FilePath,
  sTmpDir                :: String,      -- no trailing '/'
  -- You shouldn't need to look things up in rawSettings directly.
  -- They should have their own fields instead.
  sRawSettings           :: [(String, String)],
  sExtraGccViaCFlags     :: [String],
  sSystemPackageConfig   :: FilePath,
  sLdSupportsCompactUnwind :: Bool,
  sLdSupportsBuildId       :: Bool,
  sLdSupportsFilelist      :: Bool,
  sLdIsGnuLd               :: Bool,
  -- commands for particular phases
  sPgm_L                 :: String,
  sPgm_P                 :: (String,[Option]),
  sPgm_F                 :: String,
  sPgm_c                 :: (String,[Option]),
  sPgm_s                 :: (String,[Option]),
  sPgm_a                 :: (String,[Option]),
  sPgm_l                 :: (String,[Option]),
  sPgm_dll               :: (String,[Option]),
  sPgm_T                 :: String,
  sPgm_sysman            :: String,
  sPgm_windres           :: String,
  sPgm_lo                :: (String,[Option]), -- LLVM: opt llvm optimiser
  sPgm_lc                :: (String,[Option]), -- LLVM: llc static compiler
  -- options for particular phases
  sOpt_L                 :: [String],
  sOpt_P                 :: [String],
  sOpt_F                 :: [String],
  sOpt_c                 :: [String],
  sOpt_a                 :: [String],
  sOpt_l                 :: [String],
  sOpt_windres           :: [String],
  sOpt_lo                :: [String], -- LLVM: llvm optimiser
  sOpt_lc                :: [String], -- LLVM: llc static compiler

  sPlatformConstants     :: PlatformConstants
 }

targetPlatform :: DynFlags -> Platform
targetPlatform dflags = sTargetPlatform (settings dflags)