{-# LANGUAGE CPP #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TupleSections #-}

-----------------------------------------------------------------------------

-- |
-- Module      :  Distribution.Simple.Build
-- Copyright   :  Isaac Jones 2003-2005,
--                Ross Paterson 2006,
--                Duncan Coutts 2007-2008, 2012
-- License     :  BSD3
--
-- Maintainer  :  cabal-devel@haskell.org
-- Portability :  portable
--
-- This is the entry point to actually building the modules in a package. It
-- doesn't actually do much itself, most of the work is delegated to
-- compiler-specific actions. It does do some non-compiler specific bits like
-- running pre-processors.
module Distribution.Simple.Build
  ( -- * Build
    build

    -- * Repl
  , repl
  , startInterpreter

    -- * Build preparation
  , preBuildComponent
  , AutogenFile (..)
  , AutogenFileContents
  , writeBuiltinAutogenFiles
  , writeAutogenFiles

    -- * Internal package database creation
  , createInternalPackageDB
  ) where

import Distribution.Compat.Prelude
import Distribution.Utils.Generic
import Prelude ()

import Distribution.Types.ComponentLocalBuildInfo
import Distribution.Types.ComponentRequestedSpec
import Distribution.Types.Dependency
import Distribution.Types.ExecutableScope
import Distribution.Types.ForeignLib
import Distribution.Types.LibraryVisibility
import Distribution.Types.LocalBuildInfo
import Distribution.Types.ModuleRenaming
import Distribution.Types.MungedPackageId
import Distribution.Types.MungedPackageName
import Distribution.Types.ParStrat
import Distribution.Types.TargetInfo
import Distribution.Utils.Path

import Distribution.Backpack
import Distribution.Backpack.DescribeUnitId
import Distribution.Package
import qualified Distribution.Simple.GHC as GHC
import qualified Distribution.Simple.GHCJS as GHCJS
import qualified Distribution.Simple.HaskellSuite as HaskellSuite
import qualified Distribution.Simple.PackageIndex as Index
import qualified Distribution.Simple.UHC as UHC

import Distribution.Simple.Build.Macros (generateCabalMacrosHeader)
import Distribution.Simple.Build.PackageInfoModule (generatePackageInfoModule)
import Distribution.Simple.Build.PathsModule (generatePathsModule)
import qualified Distribution.Simple.Program.HcPkg as HcPkg

import Distribution.InstalledPackageInfo (InstalledPackageInfo)
import qualified Distribution.InstalledPackageInfo as IPI
import Distribution.ModuleName (ModuleName)
import qualified Distribution.ModuleName as ModuleName
import Distribution.PackageDescription
import Distribution.Simple.Compiler

import Distribution.Simple.BuildPaths
import Distribution.Simple.BuildTarget
import Distribution.Simple.BuildToolDepends
import Distribution.Simple.Configure
import Distribution.Simple.Flag
import Distribution.Simple.LocalBuildInfo
import Distribution.Simple.PreProcess
import Distribution.Simple.Program
import Distribution.Simple.Program.Builtin (haskellSuiteProgram)
import qualified Distribution.Simple.Program.GHC as GHC
import Distribution.Simple.Program.Types
import Distribution.Simple.Register
import Distribution.Simple.Setup.Build
import Distribution.Simple.Setup.Config
import Distribution.Simple.Setup.Repl
import Distribution.Simple.ShowBuildInfo
import Distribution.Simple.Test.LibV09
import Distribution.Simple.Utils
import Distribution.Utils.Json
import Distribution.Utils.ShortText (ShortText, fromShortText, toShortText)

import Distribution.Pretty
import Distribution.System
import Distribution.Verbosity
import Distribution.Version (thisVersion)

import Distribution.Compat.Graph (IsNode (..))

import Control.Monad
import qualified Data.ByteString.Lazy as LBS
import qualified Data.Map as Map
import Distribution.Simple.Errors
import System.Directory (doesFileExist, getCurrentDirectory, removeFile)
import System.FilePath (takeDirectory, (<.>), (</>))

-- -----------------------------------------------------------------------------

-- | Build the libraries and executables in this package.
build
  :: PackageDescription
  -- ^ Mostly information from the .cabal file
  -> LocalBuildInfo
  -- ^ Configuration information
  -> BuildFlags
  -- ^ Flags that the user passed to build
  -> [PPSuffixHandler]
  -- ^ preprocessors to run before compiling
  -> IO ()
build pkg_descr lbi flags suffixes = do
  checkSemaphoreSupport verbosity (compiler lbi) flags
  targets <- readTargetInfos verbosity pkg_descr lbi (buildArgs flags)
  let componentsToBuild = neededTargetsInBuildOrder' pkg_descr lbi (map nodeKey targets)
  info verbosity $
    "Component build order: "
      ++ intercalate
        ", "
        ( map
            (showComponentName . componentLocalName . targetCLBI)
            componentsToBuild
        )

  when (null targets) $
    -- Only bother with this message if we're building the whole package
    setupMessage verbosity "Building" (packageId pkg_descr)

  internalPackageDB <- createInternalPackageDB verbosity lbi distPref

  -- Before the actual building, dump out build-information.
  -- This way, if the actual compilation failed, the options have still been
  -- dumped.
  dumpBuildInfo verbosity distPref (configDumpBuildInfo (configFlags lbi)) pkg_descr lbi flags

  -- Now do the actual building
  (\f -> foldM_ f (installedPkgs lbi) componentsToBuild) $ \index target -> do
    preBuildComponent verbosity lbi target
    let comp = targetComponent target
        clbi = targetCLBI target
        bi = componentBuildInfo comp
        progs' = addInternalBuildTools pkg_descr lbi bi (withPrograms lbi)
        lbi' =
          lbi
            { withPrograms = progs'
            , withPackageDB = withPackageDB lbi ++ [internalPackageDB]
            , installedPkgs = index
            }
    par_strat <-
      toFlag <$> case buildUseSemaphore flags of
        Flag sem_name -> case buildNumJobs flags of
          Flag{} -> do
            warn verbosity $ "Ignoring -j due to --semaphore"
            return $ UseSem sem_name
          NoFlag -> return $ UseSem sem_name
        NoFlag -> return $ case buildNumJobs flags of
          Flag n -> NumJobs n
          NoFlag -> Serial
    mb_ipi <-
      buildComponent
        flags
        par_strat
        pkg_descr
        lbi'
        suffixes
        comp
        clbi
        distPref
    return (maybe index (Index.insert `flip` index) mb_ipi)

  return ()
  where
    distPref = fromFlag (buildDistPref flags)
    verbosity = fromFlag (buildVerbosity flags)

-- | Check for conditions that would prevent the build from succeeding.
checkSemaphoreSupport
  :: Verbosity -> Compiler -> BuildFlags -> IO ()
checkSemaphoreSupport verbosity comp flags = do
  unless (jsemSupported comp || (isNothing (flagToMaybe (buildUseSemaphore flags)))) $
    dieWithException verbosity CheckSemaphoreSupport

-- | Write available build information for 'LocalBuildInfo' to disk.
--
-- Dumps detailed build information 'build-info.json' to the given directory.
-- Build information contains basics such as compiler details, but also
-- lists what modules a component contains and how to compile the component, assuming
-- lib:Cabal made sure that dependencies are up-to-date.
dumpBuildInfo
  :: Verbosity
  -> FilePath
  -- ^ To which directory should the build-info be dumped?
  -> Flag DumpBuildInfo
  -- ^ Should we dump detailed build information for this component?
  -> PackageDescription
  -- ^ Mostly information from the .cabal file
  -> LocalBuildInfo
  -- ^ Configuration information
  -> BuildFlags
  -- ^ Flags that the user passed to build
  -> IO ()
dumpBuildInfo verbosity distPref dumpBuildInfoFlag pkg_descr lbi flags = do
  when shouldDumpBuildInfo $ do
    -- Changing this line might break consumers of the dumped build info.
    -- Announce changes on mailing lists!
    let activeTargets = allTargetsInBuildOrder' pkg_descr lbi
    info verbosity $
      "Dump build information for: "
        ++ intercalate
          ", "
          ( map
              (showComponentName . componentLocalName . targetCLBI)
              activeTargets
          )
    pwd <- getCurrentDirectory

    (compilerProg, _) <- case flavorToProgram (compilerFlavor (compiler lbi)) of
      Nothing ->
        dieWithException verbosity $ UnknownCompilerFlavor (compilerFlavor (compiler lbi))
      Just program -> requireProgram verbosity program (withPrograms lbi)

    let (warns, json) = mkBuildInfo pwd pkg_descr lbi flags (compilerProg, compiler lbi) activeTargets
        buildInfoText = renderJson json
    unless (null warns) $
      warn verbosity $
        "Encountered warnings while dumping build-info:\n"
          ++ unlines warns
    LBS.writeFile (buildInfoPref distPref) buildInfoText

  when (not shouldDumpBuildInfo) $ do
    -- Remove existing build-info.json as it might be outdated now.
    exists <- doesFileExist (buildInfoPref distPref)
    when exists $ removeFile (buildInfoPref distPref)
  where
    shouldDumpBuildInfo = fromFlagOrDefault NoDumpBuildInfo dumpBuildInfoFlag == DumpBuildInfo

    -- \| Given the flavor of the compiler, try to find out
    -- which program we need.
    flavorToProgram :: CompilerFlavor -> Maybe Program
    flavorToProgram GHC = Just ghcProgram
    flavorToProgram GHCJS = Just ghcjsProgram
    flavorToProgram UHC = Just uhcProgram
    flavorToProgram JHC = Just jhcProgram
    flavorToProgram HaskellSuite{} = Just haskellSuiteProgram
    flavorToProgram _ = Nothing

repl
  :: PackageDescription
  -- ^ Mostly information from the .cabal file
  -> LocalBuildInfo
  -- ^ Configuration information
  -> ReplFlags
  -- ^ Flags that the user passed to build
  -> [PPSuffixHandler]
  -- ^ preprocessors to run before compiling
  -> [String]
  -> IO ()
repl pkg_descr lbi flags suffixes args = do
  let distPref = fromFlag (replDistPref flags)
      verbosity = fromFlag (replVerbosity flags)

  target <-
    readTargetInfos verbosity pkg_descr lbi args >>= \r -> case r of
      -- This seems DEEPLY questionable.
      [] -> case allTargetsInBuildOrder' pkg_descr lbi of
        (target : _) -> return target
        [] -> dieWithException verbosity $ FailedToDetermineTarget
      [target] -> return target
      _ -> dieWithException verbosity $ NoMultipleTargets
  let componentsToBuild = neededTargetsInBuildOrder' pkg_descr lbi [nodeKey target]
  debug verbosity $
    "Component build order: "
      ++ intercalate
        ", "
        ( map
            (showComponentName . componentLocalName . targetCLBI)
            componentsToBuild
        )

  internalPackageDB <- createInternalPackageDB verbosity lbi distPref

  let lbiForComponent comp lbi' =
        lbi'
          { withPackageDB = withPackageDB lbi ++ [internalPackageDB]
          , withPrograms =
              addInternalBuildTools
                pkg_descr
                lbi'
                (componentBuildInfo comp)
                (withPrograms lbi')
          }

  -- build any dependent components
  sequence_
    [ do
      let clbi = targetCLBI subtarget
          comp = targetComponent subtarget
          lbi' = lbiForComponent comp lbi
      preBuildComponent verbosity lbi subtarget
      buildComponent
        mempty{buildVerbosity = toFlag verbosity}
        NoFlag
        pkg_descr
        lbi'
        suffixes
        comp
        clbi
        distPref
    | subtarget <- safeInit componentsToBuild
    ]

  -- REPL for target components
  let clbi = targetCLBI target
      comp = targetComponent target
      lbi' = lbiForComponent comp lbi
  preBuildComponent verbosity lbi target
  replComponent flags verbosity pkg_descr lbi' suffixes comp clbi distPref

-- | Start an interpreter without loading any package files.
startInterpreter
  :: Verbosity
  -> ProgramDb
  -> Compiler
  -> Platform
  -> PackageDBStack
  -> IO ()
startInterpreter verbosity programDb comp platform packageDBs =
  case compilerFlavor comp of
    GHC -> GHC.startInterpreter verbosity programDb comp platform packageDBs
    GHCJS -> GHCJS.startInterpreter verbosity programDb comp platform packageDBs
    _ -> dieWithException verbosity REPLNotSupported

buildComponent
  :: BuildFlags
  -> Flag ParStrat
  -> PackageDescription
  -> LocalBuildInfo
  -> [PPSuffixHandler]
  -> Component
  -> ComponentLocalBuildInfo
  -> FilePath
  -> IO (Maybe InstalledPackageInfo)
buildComponent flags _ _ _ _ (CTest TestSuite{testInterface = TestSuiteUnsupported tt}) _ _ =
  dieWithException (fromFlag $ buildVerbosity flags) $ NoSupportBuildingTestSuite tt
buildComponent flags _ _ _ _ (CBench Benchmark{benchmarkInterface = BenchmarkUnsupported tt}) _ _ =
  dieWithException (fromFlag $ buildVerbosity flags) $ NoSupportBuildingBenchMark tt
buildComponent
  flags
  numJobs
  pkg_descr
  lbi0
  suffixes
  comp@( CTest
          test@TestSuite{testInterface = TestSuiteLibV09{}}
        )
  clbi -- This ComponentLocalBuildInfo corresponds to a detailed
  -- test suite and not a real component. It should not
  -- be used, except to construct the CLBIs for the
  -- library and stub executable that will actually be
  -- built.
  distPref =
    do
      let verbosity = fromFlag $ buildVerbosity flags
      pwd <- getCurrentDirectory
      let (pkg, lib, libClbi, lbi, ipi, exe, exeClbi) =
            testSuiteLibV09AsLibAndExe pkg_descr test clbi lbi0 distPref pwd
      preprocessComponent pkg_descr comp lbi clbi False verbosity suffixes
      extras <- preprocessExtras verbosity comp lbi -- TODO find cpphs processed files
      (genDir, generatedExtras) <- generateCode (testCodeGenerators test) (testName test) pkg_descr (testBuildInfo test) lbi clbi verbosity
      setupMessage'
        verbosity
        "Building"
        (packageId pkg_descr)
        (componentLocalName clbi)
        (maybeComponentInstantiatedWith clbi)
      let libbi = libBuildInfo lib
          lib' = lib{libBuildInfo = addSrcDir (addExtraOtherModules libbi generatedExtras) genDir}
      buildLib flags numJobs pkg lbi lib' libClbi
      -- NB: need to enable multiple instances here, because on 7.10+
      -- the package name is the same as the library, and we still
      -- want the registration to go through.
      registerPackage
        verbosity
        (compiler lbi)
        (withPrograms lbi)
        (withPackageDB lbi)
        ipi
        HcPkg.defaultRegisterOptions
          { HcPkg.registerMultiInstance = True
          }
      let ebi = buildInfo exe
          -- NB: The stub executable is linked against the test-library
          --     which already contains all `other-modules`, so we need
          --     to remove those from the stub-exe's build-info
          exe' = exe{buildInfo = (addExtraCSources ebi extras){otherModules = []}}
      buildExe verbosity numJobs pkg_descr lbi exe' exeClbi
      return Nothing -- Can't depend on test suite
buildComponent
  flags
  numJobs
  pkg_descr
  lbi
  suffixes
  comp
  clbi
  distPref =
    do
      let verbosity = fromFlag $ buildVerbosity flags
      preprocessComponent pkg_descr comp lbi clbi False verbosity suffixes
      extras <- preprocessExtras verbosity comp lbi
      setupMessage'
        verbosity
        "Building"
        (packageId pkg_descr)
        (componentLocalName clbi)
        (maybeComponentInstantiatedWith clbi)
      case comp of
        CLib lib -> do
          let libbi = libBuildInfo lib
              lib' =
                lib
                  { libBuildInfo =
                      flip addExtraAsmSources extras $
                        flip addExtraCmmSources extras $
                          flip addExtraCxxSources extras $
                            flip addExtraCSources extras $
                              flip addExtraJsSources extras $
                                libbi
                  }

          buildLib flags numJobs pkg_descr lbi lib' clbi

          let oneComponentRequested (OneComponentRequestedSpec _) = True
              oneComponentRequested _ = False
          -- Don't register inplace if we're only building a single component;
          -- it's not necessary because there won't be any subsequent builds
          -- that need to tag us
          if (not (oneComponentRequested (componentEnabledSpec lbi)))
            then do
              -- Register the library in-place, so exes can depend
              -- on internally defined libraries.
              pwd <- getCurrentDirectory
              let
                -- The in place registration uses the "-inplace" suffix, not an ABI hash
                installedPkgInfo =
                  inplaceInstalledPackageInfo
                    pwd
                    distPref
                    pkg_descr
                    -- NB: Use a fake ABI hash to avoid
                    -- needing to recompute it every build.
                    (mkAbiHash "inplace")
                    lib'
                    lbi
                    clbi
              debug verbosity $ "Registering inplace:\n" ++ (IPI.showInstalledPackageInfo installedPkgInfo)
              registerPackage
                verbosity
                (compiler lbi)
                (withPrograms lbi)
                (withPackageDB lbi)
                installedPkgInfo
                HcPkg.defaultRegisterOptions
                  { HcPkg.registerMultiInstance = True
                  }
              return (Just installedPkgInfo)
            else return Nothing
        CFLib flib -> do
          buildFLib verbosity numJobs pkg_descr lbi flib clbi
          return Nothing
        CExe exe -> do
          let ebi = buildInfo exe
              exe' = exe{buildInfo = addExtraCSources ebi extras}
          buildExe verbosity numJobs pkg_descr lbi exe' clbi
          return Nothing
        CTest test@TestSuite{testInterface = TestSuiteExeV10{}} -> do
          let exe = testSuiteExeV10AsExe test
          (genDir, generatedExtras) <- generateCode (testCodeGenerators test) (testName test) pkg_descr (testBuildInfo test) lbi clbi verbosity
          let ebi = buildInfo exe
              exe' = exe{buildInfo = addSrcDir (addExtraOtherModules (addExtraCSources ebi extras) generatedExtras) genDir} -- todo extend hssrcdirs
          buildExe verbosity numJobs pkg_descr lbi exe' clbi
          return Nothing
        CBench bm@Benchmark{benchmarkInterface = BenchmarkExeV10{}} -> do
          let exe = benchmarkExeV10asExe bm
          let ebi = buildInfo exe
              exe' = exe{buildInfo = addExtraCSources ebi extras}
          buildExe verbosity numJobs pkg_descr lbi exe' clbi
          return Nothing
#if __GLASGOW_HASKELL__ < 811
-- silence pattern-match warnings prior to GHC 9.0
        _ -> error "impossible"
#endif

generateCode
  :: [String]
  -> UnqualComponentName
  -> PackageDescription
  -> BuildInfo
  -> LocalBuildInfo
  -> ComponentLocalBuildInfo
  -> Verbosity
  -> IO (FilePath, [ModuleName.ModuleName])
generateCode codeGens nm pdesc bi lbi clbi verbosity = do
  when (not . null $ codeGens) $ createDirectoryIfMissingVerbose verbosity True tgtDir
  (\x -> (tgtDir, x)) . concat <$> mapM go codeGens
  where
    allLibs = (maybe id (:) $ library pdesc) (subLibraries pdesc)
    dependencyLibs = filter (const True) allLibs -- intersect with componentPackageDeps of clbi
    srcDirs = concatMap (hsSourceDirs . libBuildInfo) dependencyLibs
    nm' = unUnqualComponentName nm
    tgtDir = buildDir lbi </> nm' </> nm' ++ "-gen"
    go :: String -> IO [ModuleName.ModuleName]
    go codeGenProg =
      fmap fromString . lines
        <$> getDbProgramOutput
          verbosity
          (simpleProgram codeGenProg)
          (withPrograms lbi)
          ( (tgtDir : map getSymbolicPath srcDirs)
              ++ ( "--"
                    : GHC.renderGhcOptions (compiler lbi) (hostPlatform lbi) (GHC.componentGhcOptions verbosity lbi bi clbi tgtDir)
                 )
          )

-- | Add extra C sources generated by preprocessing to build
-- information.
addExtraCSources :: BuildInfo -> [FilePath] -> BuildInfo
addExtraCSources bi extras = bi{cSources = new}
  where
    new = ordNub (extras ++ cSources bi)

-- | Add extra C++ sources generated by preprocessing to build
-- information.
addExtraCxxSources :: BuildInfo -> [FilePath] -> BuildInfo
addExtraCxxSources bi extras = bi{cxxSources = new}
  where
    new = ordNub (extras ++ cxxSources bi)

-- | Add extra C-- sources generated by preprocessing to build
-- information.
addExtraCmmSources :: BuildInfo -> [FilePath] -> BuildInfo
addExtraCmmSources bi extras = bi{cmmSources = new}
  where
    new = ordNub (extras ++ cmmSources bi)

-- | Add extra ASM sources generated by preprocessing to build
-- information.
addExtraAsmSources :: BuildInfo -> [FilePath] -> BuildInfo
addExtraAsmSources bi extras = bi{asmSources = new}
  where
    new = ordNub (extras ++ asmSources bi)

-- | Add extra JS sources generated by preprocessing to build
-- information.
addExtraJsSources :: BuildInfo -> [FilePath] -> BuildInfo
addExtraJsSources bi extras = bi{jsSources = new}
  where
    new = ordNub (extras ++ jsSources bi)

-- | Add extra HS modules generated by preprocessing to build
-- information.
addExtraOtherModules :: BuildInfo -> [ModuleName.ModuleName] -> BuildInfo
addExtraOtherModules bi extras = bi{otherModules = new}
  where
    new = ordNub (extras ++ otherModules bi)

-- | Add extra source dir for generated modules.
addSrcDir :: BuildInfo -> FilePath -> BuildInfo
addSrcDir bi extra = bi{hsSourceDirs = new}
  where
    new = ordNub (unsafeMakeSymbolicPath extra : hsSourceDirs bi)

replComponent
  :: ReplFlags
  -> Verbosity
  -> PackageDescription
  -> LocalBuildInfo
  -> [PPSuffixHandler]
  -> Component
  -> ComponentLocalBuildInfo
  -> FilePath
  -> IO ()
replComponent _ verbosity _ _ _ (CTest TestSuite{testInterface = TestSuiteUnsupported tt}) _ _ =
  dieWithException verbosity $ NoSupportBuildingTestSuite tt
replComponent _ verbosity _ _ _ (CBench Benchmark{benchmarkInterface = BenchmarkUnsupported tt}) _ _ =
  dieWithException verbosity $ NoSupportBuildingBenchMark tt
replComponent
  replFlags
  verbosity
  pkg_descr
  lbi0
  suffixes
  comp@( CTest
          test@TestSuite{testInterface = TestSuiteLibV09{}}
        )
  clbi
  distPref = do
    pwd <- getCurrentDirectory
    let (pkg, lib, libClbi, lbi, _, _, _) =
          testSuiteLibV09AsLibAndExe pkg_descr test clbi lbi0 distPref pwd
    preprocessComponent pkg_descr comp lbi clbi False verbosity suffixes
    extras <- preprocessExtras verbosity comp lbi
    let libbi = libBuildInfo lib
        lib' = lib{libBuildInfo = libbi{cSources = cSources libbi ++ extras}}
    replLib replFlags pkg lbi lib' libClbi
replComponent
  replFlags
  verbosity
  pkg_descr
  lbi
  suffixes
  comp
  clbi
  _ =
    do
      preprocessComponent pkg_descr comp lbi clbi False verbosity suffixes
      extras <- preprocessExtras verbosity comp lbi
      case comp of
        CLib lib -> do
          let libbi = libBuildInfo lib
              lib' = lib{libBuildInfo = libbi{cSources = cSources libbi ++ extras}}
          replLib replFlags pkg_descr lbi lib' clbi
        CFLib flib ->
          replFLib replFlags pkg_descr lbi flib clbi
        CExe exe -> do
          let ebi = buildInfo exe
              exe' = exe{buildInfo = ebi{cSources = cSources ebi ++ extras}}
          replExe replFlags pkg_descr lbi exe' clbi
        CTest test@TestSuite{testInterface = TestSuiteExeV10{}} -> do
          let exe = testSuiteExeV10AsExe test
          let ebi = buildInfo exe
              exe' = exe{buildInfo = ebi{cSources = cSources ebi ++ extras}}
          replExe replFlags pkg_descr lbi exe' clbi
        CBench bm@Benchmark{benchmarkInterface = BenchmarkExeV10{}} -> do
          let exe = benchmarkExeV10asExe bm
          let ebi = buildInfo exe
              exe' = exe{buildInfo = ebi{cSources = cSources ebi ++ extras}}
          replExe replFlags pkg_descr lbi exe' clbi
#if __GLASGOW_HASKELL__ < 811
-- silence pattern-match warnings prior to GHC 9.0
        _ -> error "impossible"
#endif

----------------------------------------------------
-- Shared code for buildComponent and replComponent
--

-- | Translate a exe-style 'TestSuite' component into an exe for building
testSuiteExeV10AsExe :: TestSuite -> Executable
testSuiteExeV10AsExe test@TestSuite{testInterface = TestSuiteExeV10 _ mainFile} =
  Executable
    { exeName = testName test
    , modulePath = mainFile
    , exeScope = ExecutablePublic
    , buildInfo = testBuildInfo test
    }
testSuiteExeV10AsExe TestSuite{} = error "testSuiteExeV10AsExe: wrong kind"

-- | Translate a exe-style 'Benchmark' component into an exe for building
benchmarkExeV10asExe :: Benchmark -> Executable
benchmarkExeV10asExe bm@Benchmark{benchmarkInterface = BenchmarkExeV10 _ mainFile} =
  Executable
    { exeName = benchmarkName bm
    , modulePath = mainFile
    , exeScope = ExecutablePublic
    , buildInfo = benchmarkBuildInfo bm
    }
benchmarkExeV10asExe Benchmark{} = error "benchmarkExeV10asExe: wrong kind"

-- | Translate a lib-style 'TestSuite' component into a lib + exe for building
testSuiteLibV09AsLibAndExe
  :: PackageDescription
  -> TestSuite
  -> ComponentLocalBuildInfo
  -> LocalBuildInfo
  -> FilePath
  -> FilePath
  -> ( PackageDescription
     , Library
     , ComponentLocalBuildInfo
     , LocalBuildInfo
     , IPI.InstalledPackageInfo
     , Executable
     , ComponentLocalBuildInfo
     )
testSuiteLibV09AsLibAndExe
  pkg_descr
  test@TestSuite{testInterface = TestSuiteLibV09 _ m}
  clbi
  lbi
  distPref
  pwd =
    (pkg, lib, libClbi, lbi, ipi, exe, exeClbi)
    where
      bi = testBuildInfo test
      lib =
        Library
          { libName = LMainLibName
          , exposedModules = [m]
          , reexportedModules = []
          , signatures = []
          , libExposed = True
          , libVisibility = LibraryVisibilityPrivate
          , libBuildInfo = bi
          }
      -- This is, like, the one place where we use a CTestName for a library.
      -- Should NOT use library name, since that could conflict!
      PackageIdentifier pkg_name pkg_ver = package pkg_descr
      -- Note: we do make internal library from the test!
      compat_name = MungedPackageName pkg_name (LSubLibName (testName test))
      compat_key = computeCompatPackageKey (compiler lbi) compat_name pkg_ver (componentUnitId clbi)
      libClbi =
        LibComponentLocalBuildInfo
          { componentPackageDeps = componentPackageDeps clbi
          , componentInternalDeps = componentInternalDeps clbi
          , componentIsIndefinite_ = False
          , componentExeDeps = componentExeDeps clbi
          , componentLocalName = CLibName $ LSubLibName $ testName test
          , componentIsPublic = False
          , componentIncludes = componentIncludes clbi
          , componentUnitId = componentUnitId clbi
          , componentComponentId = componentComponentId clbi
          , componentInstantiatedWith = []
          , componentCompatPackageName = compat_name
          , componentCompatPackageKey = compat_key
          , componentExposedModules = [IPI.ExposedModule m Nothing]
          }
      pkgName' = mkPackageName $ prettyShow compat_name
      pkg =
        pkg_descr
          { package = (package pkg_descr){pkgName = pkgName'}
          , executables = []
          , testSuites = []
          , subLibraries = [lib]
          }
      ipi = inplaceInstalledPackageInfo pwd distPref pkg (mkAbiHash "") lib lbi libClbi
      testDir =
        buildDir lbi
          </> stubName test
          </> stubName test
          ++ "-tmp"
      testLibDep =
        Dependency
          pkgName'
          (thisVersion $ pkgVersion $ package pkg_descr)
          mainLibSet
      exe =
        Executable
          { exeName = mkUnqualComponentName $ stubName test
          , modulePath = stubFilePath test
          , exeScope = ExecutablePublic
          , buildInfo =
              (testBuildInfo test)
                { hsSourceDirs = [unsafeMakeSymbolicPath testDir]
                , targetBuildDepends =
                    testLibDep
                      : targetBuildDepends (testBuildInfo test)
                }
          }
      -- \| The stub executable needs a new 'ComponentLocalBuildInfo'
      -- that exposes the relevant test suite library.
      deps =
        (IPI.installedUnitId ipi, mungedId ipi)
          : ( filter
                ( \(_, x) ->
                    let name = prettyShow $ mungedName x
                     in name == "Cabal" || name == "base"
                )
                (componentPackageDeps clbi)
            )
      exeClbi =
        ExeComponentLocalBuildInfo
          { -- TODO: this is a hack, but as long as this is unique
            -- (doesn't clobber something) we won't run into trouble
            componentUnitId = mkUnitId (stubName test)
          , componentComponentId = mkComponentId (stubName test)
          , componentInternalDeps = [componentUnitId clbi]
          , componentExeDeps = []
          , componentLocalName = CExeName $ mkUnqualComponentName $ stubName test
          , componentPackageDeps = deps
          , -- Assert DefUnitId invariant!
            -- Executable can't be indefinite, so dependencies must
            -- be definite packages.
            componentIncludes =
              map ((,defaultRenaming) . DefiniteUnitId . unsafeMkDefUnitId . fst) deps
          }
testSuiteLibV09AsLibAndExe _ TestSuite{} _ _ _ _ = error "testSuiteLibV09AsLibAndExe: wrong kind"

-- | Initialize a new package db file for libraries defined
-- internally to the package.
createInternalPackageDB
  :: Verbosity
  -> LocalBuildInfo
  -> FilePath
  -> IO PackageDB
createInternalPackageDB verbosity lbi distPref = do
  existsAlready <- doesPackageDBExist dbPath
  when existsAlready $ deletePackageDB dbPath
  createPackageDB verbosity (compiler lbi) (withPrograms lbi) False dbPath
  return (SpecificPackageDB dbPath)
  where
    dbPath = internalPackageDBPath lbi distPref

addInternalBuildTools
  :: PackageDescription
  -> LocalBuildInfo
  -> BuildInfo
  -> ProgramDb
  -> ProgramDb
addInternalBuildTools pkg lbi bi progs =
  foldr updateProgram progs internalBuildTools
  where
    internalBuildTools =
      [ simpleConfiguredProgram toolName' (FoundOnSystem toolLocation)
      | toolName <- getAllInternalToolDependencies pkg bi
      , let toolName' = unUnqualComponentName toolName
      , let toolLocation = buildDir lbi </> toolName' </> toolName' <.> exeExtension (hostPlatform lbi)
      ]

-- TODO: build separate libs in separate dirs so that we can build
-- multiple libs, e.g. for 'LibTest' library-style test suites
buildLib
  :: BuildFlags
  -> Flag ParStrat
  -> PackageDescription
  -> LocalBuildInfo
  -> Library
  -> ComponentLocalBuildInfo
  -> IO ()
buildLib flags numJobs pkg_descr lbi lib clbi =
  let verbosity = fromFlag $ buildVerbosity flags
   in case compilerFlavor (compiler lbi) of
        GHC -> GHC.buildLib flags numJobs pkg_descr lbi lib clbi
        GHCJS -> GHCJS.buildLib verbosity numJobs pkg_descr lbi lib clbi
        UHC -> UHC.buildLib verbosity pkg_descr lbi lib clbi
        HaskellSuite{} -> HaskellSuite.buildLib verbosity pkg_descr lbi lib clbi
        _ -> dieWithException verbosity BuildingNotSupportedWithCompiler

-- | Build a foreign library
--
-- NOTE: We assume that we already checked that we can actually build the
-- foreign library in configure.
buildFLib
  :: Verbosity
  -> Flag ParStrat
  -> PackageDescription
  -> LocalBuildInfo
  -> ForeignLib
  -> ComponentLocalBuildInfo
  -> IO ()
buildFLib verbosity numJobs pkg_descr lbi flib clbi =
  case compilerFlavor (compiler lbi) of
    GHC -> GHC.buildFLib verbosity numJobs pkg_descr lbi flib clbi
    _ -> dieWithException verbosity BuildingNotSupportedWithCompiler

buildExe
  :: Verbosity
  -> Flag ParStrat
  -> PackageDescription
  -> LocalBuildInfo
  -> Executable
  -> ComponentLocalBuildInfo
  -> IO ()
buildExe verbosity numJobs pkg_descr lbi exe clbi =
  case compilerFlavor (compiler lbi) of
    GHC -> GHC.buildExe verbosity numJobs pkg_descr lbi exe clbi
    GHCJS -> GHCJS.buildExe verbosity numJobs pkg_descr lbi exe clbi
    UHC -> UHC.buildExe verbosity pkg_descr lbi exe clbi
    _ -> dieWithException verbosity BuildingNotSupportedWithCompiler

replLib
  :: ReplFlags
  -> PackageDescription
  -> LocalBuildInfo
  -> Library
  -> ComponentLocalBuildInfo
  -> IO ()
replLib replFlags pkg_descr lbi lib clbi =
  let verbosity = fromFlag $ replVerbosity replFlags
      opts = replReplOptions replFlags
   in case compilerFlavor (compiler lbi) of
        -- 'cabal repl' doesn't need to support 'ghc --make -j', so we just pass
        -- NoFlag as the numJobs parameter.
        GHC -> GHC.replLib replFlags NoFlag pkg_descr lbi lib clbi
        GHCJS -> GHCJS.replLib (replOptionsFlags opts) verbosity NoFlag pkg_descr lbi lib clbi
        _ -> dieWithException verbosity REPLNotSupported

replExe
  :: ReplFlags
  -> PackageDescription
  -> LocalBuildInfo
  -> Executable
  -> ComponentLocalBuildInfo
  -> IO ()
replExe flags pkg_descr lbi exe clbi =
  let verbosity = fromFlag $ replVerbosity flags
   in case compilerFlavor (compiler lbi) of
        GHC -> GHC.replExe flags NoFlag pkg_descr lbi exe clbi
        GHCJS -> GHCJS.replExe (replOptionsFlags $ replReplOptions flags) verbosity NoFlag pkg_descr lbi exe clbi
        _ -> dieWithException verbosity REPLNotSupported

replFLib
  :: ReplFlags
  -> PackageDescription
  -> LocalBuildInfo
  -> ForeignLib
  -> ComponentLocalBuildInfo
  -> IO ()
replFLib flags pkg_descr lbi exe clbi =
  let verbosity = fromFlag $ replVerbosity flags
   in case compilerFlavor (compiler lbi) of
        GHC -> GHC.replFLib flags NoFlag pkg_descr lbi exe clbi
        _ -> dieWithException verbosity REPLNotSupported

-- | Pre-build steps for a component: creates the autogenerated files
-- for a particular configured component.
preBuildComponent
  :: Verbosity
  -> LocalBuildInfo
  -- ^ Configuration information
  -> TargetInfo
  -> IO ()
preBuildComponent verbosity lbi tgt = do
  let pkg_descr = localPkgDescr lbi
      clbi = targetCLBI tgt
  createDirectoryIfMissingVerbose verbosity True (componentBuildDir lbi clbi)
  writeBuiltinAutogenFiles verbosity pkg_descr lbi clbi

-- | Generate and write to disk all built-in autogenerated files
-- for the specified component. These files will be put in the
-- autogenerated module directory for this component
-- (see 'autogenComponentsModuleDir').
--
-- This includes:
--
--  - @Paths_<pkg>.hs@,
--  - @PackageInfo_<pkg>.hs@,
--  - Backpack signature files for components that are not fully instantiated,
--  - @cabal_macros.h@.
writeBuiltinAutogenFiles
  :: Verbosity
  -> PackageDescription
  -> LocalBuildInfo
  -> ComponentLocalBuildInfo
  -> IO ()
writeBuiltinAutogenFiles verbosity pkg lbi clbi =
  writeAutogenFiles verbosity lbi clbi $ builtinAutogenFiles pkg lbi clbi

-- | Built-in autogenerated files and their contents. This includes:
--
--  - @Paths_<pkg>.hs@,
--  - @PackageInfo_<pkg>.hs@,
--  - Backpack signature files for components that are not fully instantiated,
--  - @cabal_macros.h@.
builtinAutogenFiles
  :: PackageDescription
  -> LocalBuildInfo
  -> ComponentLocalBuildInfo
  -> Map AutogenFile AutogenFileContents
builtinAutogenFiles pkg lbi clbi =
  Map.insert pathsFile pathsContents $
    Map.insert packageInfoFile packageInfoContents $
      Map.insert cppHeaderFile cppHeaderContents $
        emptySignatureModules clbi
  where
    pathsFile = AutogenModule (autogenPathsModuleName pkg) (Suffix "hs")
    pathsContents = toUTF8LBS $ generatePathsModule pkg lbi clbi
    packageInfoFile = AutogenModule (autogenPackageInfoModuleName pkg) (Suffix "hs")
    packageInfoContents = toUTF8LBS $ generatePackageInfoModule pkg lbi
    cppHeaderFile = AutogenFile $ toShortText cppHeaderName
    cppHeaderContents = toUTF8LBS $ generateCabalMacrosHeader pkg lbi clbi

-- | An empty @".hsig"@ Backpack signature module for each requirement, so that
-- GHC has a source file to look at it when it needs to typecheck
-- a signature.  It's harmless to generate these modules, even when
-- there is a real @hsig@ file written by the user, since
-- include path ordering ensures that the real @hsig@ file
-- will always be picked up before the autogenerated one.
emptySignatureModules
  :: ComponentLocalBuildInfo
  -> Map AutogenFile AutogenFileContents
emptySignatureModules clbi =
  case clbi of
    LibComponentLocalBuildInfo{componentInstantiatedWith = insts} ->
      Map.fromList
        [ ( AutogenModule modName (Suffix "hsig")
          , emptyHsigFile modName
          )
        | (modName, _) <- insts
        ]
    _ -> Map.empty
  where
    emptyHsigFile :: ModuleName -> AutogenFileContents
    emptyHsigFile modName =
      toUTF8LBS $
        "{-# OPTIONS_GHC -w #-}\n"
          ++ "{-# LANGUAGE NoImplicitPrelude #-}\n"
          ++ "signature "
          ++ prettyShow modName
          ++ " where"

data AutogenFile
  = AutogenModule !ModuleName !Suffix
  | AutogenFile !ShortText
  deriving (Show, Eq, Ord)

-- | A representation of the contents of an autogenerated file.
type AutogenFileContents = LBS.ByteString

-- | Write the given autogenerated files in the autogenerated modules
-- directory for the component.
writeAutogenFiles
  :: Verbosity
  -> LocalBuildInfo
  -> ComponentLocalBuildInfo
  -> Map AutogenFile AutogenFileContents
  -> IO ()
writeAutogenFiles verbosity lbi clbi autogenFiles = do
  -- Ensure that the overall autogenerated files directory exists.
  createDirectoryIfMissingVerbose verbosity True autogenDir
  for_ (Map.assocs autogenFiles) $ \(file, contents) -> do
    let path = case file of
          AutogenModule modName (Suffix ext) ->
            autogenDir </> ModuleName.toFilePath modName <.> ext
          AutogenFile fileName ->
            autogenDir </> fromShortText fileName
        dir = takeDirectory path
    -- Ensure that the directory subtree for this autogenerated file exists.
    createDirectoryIfMissingVerbose verbosity True dir
    -- Write the contents of the file.
    rewriteFileLBS verbosity path contents
  where
    autogenDir = autogenComponentModulesDir lbi clbi