GHC.PackageDb

This module provides the view of GHC's database of registered packages that is shared between GHC the compiler/library, and the ghc-pkg program. It defines the database format that is shared between GHC and ghc-pkg.

The database format, and this library are constructed so that GHC does not have to depend on the Cabal library. The ghc-pkg program acts as the gateway between the external package format (which is defined by Cabal) and the internal package format which is specialised just for GHC.

GHC the compiler only needs some of the information which is kept about registerd packages, such as module names, various paths etc. On the other hand ghc-pkg has to keep all the information from Cabal packages and be able to regurgitate it for users and other tools.

The first trick is that we duplicate some of the information in the package database. We essentially keep two versions of the datbase in one file, one version used only by ghc-pkg which keeps the full information (using the serialised form of the InstalledPackageInfo type defined by the Cabal library); and a second version written by ghc-pkg and read by GHC which has just the subset of information that GHC needs.

The second trick is that this module only defines in detail the format of the second version -- the bit GHC uses -- and the part managed by ghc-pkg is kept in the file but here we treat it as an opaque blob of data. That way this library avoids depending on Cabal.

Documentation

data InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod

This is a subset of Cabal's InstalledPackageInfo, with just the bits that GHC is interested in. See Cabal's documentation for a more detailed description of all of the fields.

Constructors

InstalledPackageInfo

Fields

• unitId :: instunitid
• componentId :: compid
• instantiatedWith :: [(modulename, mod)]
• sourcePackageId :: srcpkgid
• packageName :: srcpkgname
• packageVersion :: Version
• sourceLibName :: Maybe srcpkgname
• abiHash :: String
• depends :: [instunitid]
• abiDepends :: [(instunitid, String)]

  Like depends, but each dependency is annotated with the ABI hash we expect the dependency to respect.

• importDirs :: [FilePath]
• hsLibraries :: [String]
• extraLibraries :: [String]
• extraGHCiLibraries :: [String]
• libraryDirs :: [FilePath]
• libraryDynDirs :: [FilePath]
• frameworks :: [String]
• frameworkDirs :: [FilePath]
• ldOptions :: [String]
• ccOptions :: [String]
• includes :: [String]
• includeDirs :: [FilePath]
• haddockInterfaces :: [FilePath]
• haddockHTMLs :: [FilePath]
• exposedModules :: [(modulename, Maybe mod)]
• hiddenModules :: [modulename]
• indefinite :: Bool
• exposed :: Bool
• trusted :: Bool

Instances

(Eq instunitid, Eq compid, Eq modulename, Eq mod, Eq srcpkgid, Eq srcpkgname) => Eq (InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod)

Defined in GHC.PackageDb

Methods

(==) :: InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> Bool

(/=) :: InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> Bool

(Show instunitid, Show compid, Show modulename, Show mod, Show srcpkgid, Show srcpkgname) => Show (InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod)

Defined in GHC.PackageDb

Methods

showsPrec :: Int -> InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> ShowS

show :: InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod -> String

showList :: [InstalledPackageInfo compid srcpkgid srcpkgname instunitid unitid modulename mod] -> ShowS

RepInstalledPackageInfo a b c d e f g => Binary (InstalledPackageInfo a b c d e f g)

Defined in GHC.PackageDb

Methods

put :: InstalledPackageInfo a b c d e f g -> Put

get :: Get (InstalledPackageInfo a b c d e f g)

putList :: [InstalledPackageInfo a b c d e f g] -> Put

data DbModule instunitid compid unitid modulename mod

ghc-boot's copy of Module, i.e. what is serialized to the database. Use DbUnitIdModuleRep to convert it into an actual Module. It has phantom type parameters as this is the most convenient way to avoid undecidable instances.

Constructors

DbModule

Fields

• dbModuleUnitId :: unitid
• dbModuleName :: modulename

DbModuleVar

Fields

• dbModuleVarName :: modulename

Instances

(Eq unitid, Eq modulename) => Eq (DbModule instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

(==) :: DbModule instunitid compid unitid modulename mod -> DbModule instunitid compid unitid modulename mod -> Bool

(/=) :: DbModule instunitid compid unitid modulename mod -> DbModule instunitid compid unitid modulename mod -> Bool

(Show unitid, Show modulename) => Show (DbModule instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

showsPrec :: Int -> DbModule instunitid compid unitid modulename mod -> ShowS

show :: DbModule instunitid compid unitid modulename mod -> String

showList :: [DbModule instunitid compid unitid modulename mod] -> ShowS

(BinaryStringRep modulename, BinaryStringRep compid, BinaryStringRep instunitid, DbUnitIdModuleRep instunitid compid unitid modulename mod) => Binary (DbModule instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

put :: DbModule instunitid compid unitid modulename mod -> Put

get :: Get (DbModule instunitid compid unitid modulename mod)

putList :: [DbModule instunitid compid unitid modulename mod] -> Put

data DbUnitId instunitid compid unitid modulename mod

ghc-boot's copy of UnitId, i.e. what is serialized to the database. Use DbUnitIdModuleRep to convert it into an actual UnitId. It has phantom type parameters as this is the most convenient way to avoid undecidable instances.

Constructors

DbUnitId compid [(modulename, mod)]

DbInstalledUnitId instunitid

Instances

(Eq compid, Eq modulename, Eq mod, Eq instunitid) => Eq (DbUnitId instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

(==) :: DbUnitId instunitid compid unitid modulename mod -> DbUnitId instunitid compid unitid modulename mod -> Bool

(/=) :: DbUnitId instunitid compid unitid modulename mod -> DbUnitId instunitid compid unitid modulename mod -> Bool

(Show compid, Show modulename, Show mod, Show instunitid) => Show (DbUnitId instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

showsPrec :: Int -> DbUnitId instunitid compid unitid modulename mod -> ShowS

show :: DbUnitId instunitid compid unitid modulename mod -> String

showList :: [DbUnitId instunitid compid unitid modulename mod] -> ShowS

(BinaryStringRep modulename, BinaryStringRep compid, BinaryStringRep instunitid, DbUnitIdModuleRep instunitid compid unitid modulename mod) => Binary (DbUnitId instunitid compid unitid modulename mod)

Defined in GHC.PackageDb

Methods

put :: DbUnitId instunitid compid unitid modulename mod -> Put

get :: Get (DbUnitId instunitid compid unitid modulename mod)

putList :: [DbUnitId instunitid compid unitid modulename mod] -> Put

class BinaryStringRep a where

Minimal complete definition

fromStringRep, toStringRep

Methods

fromStringRep :: ByteString -> a

toStringRep :: a -> ByteString

class DbUnitIdModuleRep instunitid compid unitid modulename mod | mod -> unitid, unitid -> mod, mod -> modulename, unitid -> compid, unitid -> instunitid where

A type-class for the types which can be converted into 'DbModule'/'DbUnitId'. There is only one type class because these types are mutually recursive. NB: The functional dependency helps out type inference in cases where types would be ambiguous.

Minimal complete definition

fromDbModule, toDbModule, fromDbUnitId, toDbUnitId

Methods

fromDbModule :: DbModule instunitid compid unitid modulename mod -> mod

toDbModule :: mod -> DbModule instunitid compid unitid modulename mod

fromDbUnitId :: DbUnitId instunitid compid unitid modulename mod -> unitid

toDbUnitId :: unitid -> DbUnitId instunitid compid unitid modulename mod

emptyInstalledPackageInfo :: RepInstalledPackageInfo a b c d e f g => InstalledPackageInfo a b c d e f g

data PackageDbLock

Represents a lock of a package db.

lockPackageDb :: FilePath -> IO PackageDbLock

Acquire an exclusive lock related to package DB under given location.

unlockPackageDb :: PackageDbLock -> IO ()

Release the lock related to package DB.

data DbMode

Mode to open a package db in.

Constructors

DbReadOnly

DbReadWrite

data DbOpenMode (mode :: DbMode) t where

DbOpenMode holds a value of type t but only in DbReadWrite mode. So it is like Maybe but with a type argument for the mode to enforce that the mode is used consistently.

Constructors

DbOpenReadOnly :: DbOpenMode DbReadOnly t

DbOpenReadWrite :: t -> DbOpenMode DbReadWrite t

Instances

Functor (DbOpenMode mode)

Defined in GHC.PackageDb

Methods

fmap :: (a -> b) -> DbOpenMode mode a -> DbOpenMode mode b

(<$) :: a -> DbOpenMode mode b -> DbOpenMode mode a

Foldable (DbOpenMode mode)

Defined in GHC.PackageDb

Methods

fold :: Monoid m => DbOpenMode mode m -> m

foldMap :: Monoid m => (a -> m) -> DbOpenMode mode a -> m

foldr :: (a -> b -> b) -> b -> DbOpenMode mode a -> b

foldr' :: (a -> b -> b) -> b -> DbOpenMode mode a -> b

foldl :: (b -> a -> b) -> b -> DbOpenMode mode a -> b

foldl' :: (b -> a -> b) -> b -> DbOpenMode mode a -> b

foldr1 :: (a -> a -> a) -> DbOpenMode mode a -> a

foldl1 :: (a -> a -> a) -> DbOpenMode mode a -> a

toList :: DbOpenMode mode a -> [a]

null :: DbOpenMode mode a -> Bool

length :: DbOpenMode mode a -> Int

elem :: Eq a => a -> DbOpenMode mode a -> Bool

maximum :: Ord a => DbOpenMode mode a -> a

minimum :: Ord a => DbOpenMode mode a -> a

sum :: Num a => DbOpenMode mode a -> a

product :: Num a => DbOpenMode mode a -> a

Traversable (DbOpenMode mode)

Defined in GHC.PackageDb

Methods

traverse :: Applicative f => (a -> f b) -> DbOpenMode mode a -> f (DbOpenMode mode b)

sequenceA :: Applicative f => DbOpenMode mode (f a) -> f (DbOpenMode mode a)

mapM :: Monad m => (a -> m b) -> DbOpenMode mode a -> m (DbOpenMode mode b)

sequence :: Monad m => DbOpenMode mode (m a) -> m (DbOpenMode mode a)

isDbOpenReadMode :: DbOpenMode mode t -> Bool

readPackageDbForGhc :: RepInstalledPackageInfo a b c d e f g => FilePath -> IO [InstalledPackageInfo a b c d e f g]

Read the part of the package DB that GHC is interested in.

readPackageDbForGhcPkg :: Binary pkgs => FilePath -> DbOpenMode mode t -> IO (pkgs, DbOpenMode mode PackageDbLock)

Read the part of the package DB that ghc-pkg is interested in

Note that the Binary instance for ghc-pkg's representation of packages is not defined in this package. This is because ghc-pkg uses Cabal types (and Binary instances for these) which this package does not depend on.

If we open the package db in read only mode, we get its contents. Otherwise we additionally receive a PackageDbLock that represents a lock on the database, so that we can safely update it later.

writePackageDb :: (Binary pkgs, RepInstalledPackageInfo a b c d e f g) => FilePath -> [InstalledPackageInfo a b c d e f g] -> pkgs -> IO ()

Write the whole of the package DB, both parts.