ghc-check- detect mismatches between compile-time and run-time versions of the ghc api
Safe HaskellNone



GHC version check

makeGhcVersionChecker :: IO FilePath -> SpliceQ GhcVersionChecker Source #

makeGhcVersionChecker libdir returns a function to check the run-time version of GHC against the compile-time version. It performs two checks:

  1. It checks the version of the GHC installation given the run-time libdir In some platforms, like Nix, the libdir is not fixed at compile-time
  2. It compares the version of the ghc package, if found at run-time. If not, it compares the abi of the base package.
ghcChecker :: IO(Ghc (String -> PackageCheck))
ghcChecker = $$(makeGhcVersionChecker (pure $ Just GHC.Paths.libdir))

checkGhcVersion :: IO ()
checkGhcVersion = do
    InstallationChecked packageCheck <- ghcChecker runTimeLibdir
    res <- runGhc (Just runTimeLibdir) $ do
             result <- packageCheck
             case guessCompatibility result of ...

type GhcVersionChecker = String -> IO InstallationCheck Source #

Given a run-time libdir, checks the ghc installation and returns a Ghc action to check the package database

data InstallationCheck Source #



The GHC installation looks fine. Further checks are needed for the package libraries.



The libdir points to a different GHC version



The libdir does not exist


data PackageCheckResult Source #


PackageCheckSuccess !(NonEmpty (String, PackageCheck))

All the compile time packages tested match

PackageCheckFailure !(NonEmpty (String, PackageCheck))

Found package mismatches

PackageCheckInconclusive ![String]

None of the compile time packages could be found

PackageCheckError !SomeException

An exception arised during the package check

data PackageCheck Source #



Different versions


Same version but different abi


Same version and abi


Instances details
Eq PackageCheck Source # 
Instance details

Defined in GHC.Check

Show PackageCheck Source # 
Instance details

Defined in GHC.Check

Interpreting the results

guessCompatibility :: PackageCheckResult -> CompatibilityGuess Source #

Interpret a PackageCheckResult into a yes/no GHC compatibility answer

Exports for TH

checkGhcVersion :: [(String, PackageVersion)] -> GhcVersionChecker Source #

Checks if the run-time version of the ghc package matches the given version.

If the package database contains an unstable ghc library version, we omit the package version check. This leads to a more convenient usage for working on GHC. When developing for or on GHC, you can compile GHC HEAD with a bootstrap compiler and use the freshly compiled ghc library to load programs that use the latest GHC API. We consider the ghc version to be unstable according to the GHC User Guide