Cabal-syntax/src/Distribution/Types/AbiDependency.hs

   1 {-# LANGUAGE DeriveDataTypeable #-}
   2 {-# LANGUAGE DeriveGeneric #-}
   3
   4 module Distribution.Types.AbiDependency where
   5
   6 import Distribution.Compat.Prelude
   7 import Prelude ()
   8
   9 import Distribution.Parsec
  10 import Distribution.Pretty
  11
  12 import qualified Distribution.Compat.CharParsing as P
  13 import qualified Distribution.Package as Package
  14 import qualified Text.PrettyPrint as Disp
  15
  16 -- | An ABI dependency is a dependency on a library which also
  17 -- records the ABI hash ('abiHash') of the library it depends
  18 -- on.
  19 --
  20 -- The primary utility of this is to enable an extra sanity when
  21 -- GHC loads libraries: it can check if the dependency has a matching
  22 -- ABI and if not, refuse to load this library.  This information
  23 -- is critical if we are shadowing libraries; differences in the
  24 -- ABI hash let us know what packages get shadowed by the new version
  25 -- of a package.
  26 data AbiDependency = AbiDependency
  27   { depUnitId :: Package.UnitId
  28   , depAbiHash :: Package.AbiHash
  29   }
  30   deriving (Eq, Generic, Read, Show, Typeable)
  31
  32 instance Pretty AbiDependency where
  33   pretty (AbiDependency uid abi) =
  34     pretty uid <<>> Disp.char '=' <<>> pretty abi
  35
  36 instance Parsec AbiDependency where
  37   parsec = do
  38     uid <- parsec
  39     _ <- P.char '='
  40     abi <- parsec
  41     return (AbiDependency uid abi)
  42
  43 instance Binary AbiDependency
  44 instance Structured AbiDependency
  45 instance NFData AbiDependency where rnf = genericRnf