GHC.Linker.Loader

The loader

This module deals with the top-level issues of dynamic linking (loading), calling the object-code linker and the byte-code linker where necessary.

Documentation

newtype Loader

Constructors

Loader

Fields

• loader_state :: MVar (Maybe LoaderState)

data LoaderState

Constructors

LoaderState

Fields

• closure_env :: ClosureEnv

  Current global mapping from Names to their true values

• itbl_env :: !ItblEnv

  The current global mapping from RdrNames of DataCons to info table addresses. When a new Unlinked is linked into the running image, or an existing module in the image is replaced, the itbl_env must be updated appropriately.

• bcos_loaded :: !LinkableSet

  The currently loaded interpreted modules (home package)

• objs_loaded :: !LinkableSet

  And the currently-loaded compiled modules (home package)

• pkgs_loaded :: !PkgsLoaded

  The currently-loaded packages; always object code haskell libraries, system libraries, transitive dependencies

• temp_sos :: ![(FilePath, String)]

  We need to remember the name of previous temporary DLL/.so libraries so we can link them (see #10322)

initLoaderState :: Interp -> HscEnv -> IO ()

Initialise the dynamic linker. This entails

a) Calling the C initialisation procedure,

b) Loading any packages specified on the command line,

c) Loading any packages specified on the command line, now held in the -l options in v_Opt_l,

d) Loading any .o/.dll files specified on the command line, now held in ldInputs,

e) Loading any MacOS frameworks.

NOTE: This function is idempotent; if called more than once, it does nothing. This is useful in Template Haskell, where we call it before trying to link.

uninitializedLoader :: IO Loader

showLoaderState :: Interp -> IO SDoc

Display the loader state.

getLoaderState :: Interp -> IO (Maybe LoaderState)

Load & Unload

loadExpr :: Interp -> HscEnv -> SrcSpan -> UnlinkedBCO -> IO ForeignHValue

Load a single expression, including first loading packages and modules that this expression depends on.

Raises an IO exception (ProgramError) if it can't find a compiled version of the dependents to load.

loadDecls :: Interp -> HscEnv -> SrcSpan -> CompiledByteCode -> IO ([(Name, ForeignHValue)], [Linkable], PkgsLoaded)

loadPackages :: Interp -> HscEnv -> [UnitId] -> IO ()

Load exactly the specified packages, and their dependents (unless of course they are already loaded). The dependents are loaded automatically, and it doesn't matter what order you specify the input packages.

loadModule :: Interp -> HscEnv -> Module -> IO ()

loadCmdLineLibs :: Interp -> HscEnv -> IO ()

loadName :: Interp -> HscEnv -> Name -> IO (ForeignHValue, [Linkable], PkgsLoaded)

Load the module containing the given Name and get its associated HValue.

Throws a ProgramError if loading fails or the name cannot be found.

unload

Arguments

:: Interp

-> HscEnv

-> [Linkable]

The linkables to *keep*.

-> IO ()

Unloading old objects ready for a new compilation sweep.

The compilation manager provides us with a list of linkables that it considers "stable", i.e. won't be recompiled this time around. For each of the modules current linked in memory,

• if the linkable is stable (and it's the same one -- the user may have recompiled the module on the side), we keep it,
• otherwise, we unload it.
• we also implicitly unload all temporary bindings at this point.

LoadedEnv

withExtendedLoadedEnv :: ExceptionMonad m => Interp -> [(Name, ForeignHValue)] -> m a -> m a

Temporarily extend the loaded env.

extendLoadedEnv :: Interp -> [(Name, ForeignHValue)] -> IO ()

deleteFromLoadedEnv :: Interp -> [Name] -> IO ()