GHC/Unit/Module/Location.hs

    -- | Module location
    module GHC.Unit.Module.Location
       ( ModLocation(..)
       , addBootSuffix
       , addBootSuffix_maybe
       , addBootSuffixLocn
       , addBootSuffixLocnOut
       , removeBootSuffix
       )
    where

    import GHC.Prelude
    import GHC.Unit.Types
    import GHC.Utils.Outputable

    -- | Module Location
    --
    -- Where a module lives on the file system: the actual locations
    -- of the .hs, .hi and .o files, if we have them.
    --
    -- For a module in another unit, the ml_hs_file and ml_obj_file components of
    -- ModLocation are undefined.
    --
    -- The locations specified by a ModLocation may or may not
    -- correspond to actual files yet: for example, even if the object
    -- file doesn't exist, the ModLocation still contains the path to
    -- where the object file will reside if/when it is created.

    data ModLocation
       = ModLocation {
            ml_hs_file   :: Maybe FilePath,
                    -- ^ The source file, if we have one.  Package modules
                    -- probably don't have source files.

            ml_hi_file   :: FilePath,
                    -- ^ Where the .hi file is, whether or not it exists
                    -- yet.  Always of form foo.hi, even if there is an
                    -- hi-boot file (we add the -boot suffix later)

            ml_obj_file  :: FilePath,
                    -- ^ Where the .o file is, whether or not it exists yet.
                    -- (might not exist either because the module hasn't
                    -- been compiled yet, or because it is part of a
                    -- unit with a .a file)

            ml_hie_file  :: FilePath
                    -- ^ Where the .hie file is, whether or not it exists
                    -- yet.
      } deriving Show

    instance Outputable ModLocation where
       ppr = text . show

    -- | Add the @-boot@ suffix to .hs, .hi and .o files
    addBootSuffix :: FilePath -> FilePath
    addBootSuffix path = path ++ "-boot"

    -- | Remove the @-boot@ suffix to .hs, .hi and .o files
    removeBootSuffix :: FilePath -> FilePath
    removeBootSuffix "-boot" = []
    removeBootSuffix (x:xs)  = x : removeBootSuffix xs
    removeBootSuffix []      = error "removeBootSuffix: no -boot suffix"

    -- | Add the @-boot@ suffix if the @Bool@ argument is @True@
    addBootSuffix_maybe :: IsBootInterface -> FilePath -> FilePath
    addBootSuffix_maybe is_boot path = case is_boot of
      IsBoot -> addBootSuffix path
      NotBoot -> path

    -- | Add the @-boot@ suffix to all file paths associated with the module
    addBootSuffixLocn :: ModLocation -> ModLocation
    addBootSuffixLocn locn
      = locn { ml_hs_file  = fmap addBootSuffix (ml_hs_file locn)
             , ml_hi_file  = addBootSuffix (ml_hi_file locn)
             , ml_obj_file = addBootSuffix (ml_obj_file locn)
             , ml_hie_file = addBootSuffix (ml_hie_file locn) }

    -- | Add the @-boot@ suffix to all output file paths associated with the
    -- module, not including the input file itself
    addBootSuffixLocnOut :: ModLocation -> ModLocation
    addBootSuffixLocnOut locn
      = locn { ml_hi_file  = addBootSuffix (ml_hi_file locn)
             , ml_obj_file = addBootSuffix (ml_obj_file locn)
             , ml_hie_file = addBootSuffix (ml_hie_file locn) }