This GHC plugin allows compilation to abort with an error if any non-whitelisted extension, or import is used.
This is meant to be used on a Haskell course where student answers
go through an automatic inspection before grading. The aim of the
plugin is to stop the most obvious cheating attempts, such as
passing easy recursion exercises by just import Data.List.
This is a ghc plugin. The general pattern of usage is to
-
Add
AbortPluginas a dependency to your project. -
Create a limitations file in style of the the default one, which contains whitelists of allowed imports and modules.
-
Invoke GHC with
ghc -- -Wall -fplugin=AbortPlugin -fplugin-opt=AbortPlugin:Limitations.dhall YourFile.hs
You can also use this plugin to extract the extensions and imports used by a
particular source file. This is done by prefixing the limitations filename
by +-sign. For example:
ghc -- -Wall -fplugin=AbortPlugin -fplugin-opt=AbortPlugin:+Limitations.dhall YourFile.hs
This will overwrite the limitations file if it exists.
This does not provide compilation safety! GHC allows options
such as -F -pgmF ./something_nasty which cannot be intercepted by
a compiler plugin.
A modicum of compiler safety can be obtained by careful
whitelisting of extensions and modules and checking that the
source file nor any of it's transitive imports does not contain
the string OPTIONS_GHC (or any upper/lowercase permutation of
it).