I am trying to implement the ReadConsoleInputEx(A|W) functions in kernelbase(It is needed for Microsoft's edit.exe. See bug #58252). I figured I could do that by defining a new CTL_CODE in include/wine/condrv.h. 

However, after a long time spent in exploring the source code, I don't get where the handler for the codes, such IOCTL_CONDRV_READ_INPUT are defined.

Would appreciate some direction on this. Thanks in advance.

Console ioctl are received by server/console.c and either handled directly inside Wine server, or forwarded to attached conhost (if any) (programs/conhost/conhost.c)

Given the nature of ReadConsoleInputEx (being either blocking and non blocking) depending on the passed flags, I strongly suggest staring by writing some tests (dlls/kernel32/tests/console.c) to cover the various aspects of the API

HTH

-Eric