Can I get the internal name of a package at runtime?
monkleyon at gmail.com
Sat Oct 14 15:35:28 UTC 2017
I'm experimenting with plug-ins right now. I did manage to dynamically
load functions at runtime. The caveat: Something (cabal? ghc?) mangles
the package names. For example, to load a function called "theFunction"
from a module called "Callee" in a package "Plugin", I had to address it
via the name
O…K. Most parts of that are clear, and thanks for making my package
cooler by appending a "z", but who is this Ozi guy and why is he rapping
about modems? Without knowing Ozi, the only way I found to get at this
magic string is to manually look at the actual ELF-header of the
compiled module. While that might be a robust way, it seems neither
portable nor elegant.
The "plugins" library failed too, probably for the same reason. (Or it's
under-documented. Probably both.) The "dynamic-loader" library does
something via c, therefore no.
Which brings me to the question: Is there any way for a module to get at
its own internal package name? Or even at the internal name of an
external package? If not, can I somehow recreate the magic mangling at
runtime? At first I thought the functions in the "Module", "Name" etc
modules of GHC might help – but it seems I either need an existing Name
(that I have no idea how to get) or I have to create one (with no idea
what magic mangler to call).
I'm asking this question here rather than on café as I feel that if
there is a solution, it's probably buried in the details of GHC.
Thanks for any suggestions,
More information about the ghc-devs