The following two files are generated with wayland-scanner:

input-method-protocol.c
input-method-client-protocol.h

We include them in the distribution instead of generating them, since
the Wayland protocol structure will unlikely change.  Do not modify
those files manually.

To generate them, use the wayland-scanner command as follows.  You can
find input-method.xml in the Weston source code (maybe it will be
moved to the Wayland source code later).

$ wayland-scanner code < input-method.xml \
  > input-method-protocol.c
$ wayland-scanner client-header < input-method.xml \
  > input-method-client-protocol.h