"foreign import capi" causes panic with sqlite
## Summary
Trying to `foreign import capi` a sqlite function causes a panic.
## Steps to reproduce
Install the [sqlite](https://www.sqlite.org/index.html) library in your system. For example in Ubuntu, run `apt-get install libsqlite3-0 libsqlite3-dev`.
Then try to compile the following program:
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LANGUAGE CApiFFI #-}
module Main where
import Foreign
import Foreign.C
type CTraceCallback a
= Ptr a
-> CString -- ^ UTF-8 rendering of the SQL statement text as
-- the statement first begins executing.
-> IO ()
foreign import capi "wrapper"
mkCTraceCallback :: CTraceCallback a -> IO (FunPtr (CTraceCallback a))
main :: IO ()
main = pure ()
The compilation fails with:
[1 of 1] Compiling Main ( Main.hs, Main.o )
ghc: panic! (the 'impossible' happened)
(GHC version 9.2.2:
ccallConvToInt CApiConv
If the calling convention is changed to `ccall`, the program compiles.
## Expected behavior
The program should compile with the `capi` calling convention.
## Environment
* I tried with GHC versions 8.10.7 and 9.2.2
* Operating System: Ubuntu Linux (running inside WSL2 in Windows)
issue