Jacek Caban (@jacek) commented about dlls/winewayland.drv/Makefile.in:
MODULE = winewayland.drv +UNIXLIB = winewayland.so
C_SRCS = \ dllmain.c \
- waylanddrv_main.c \
The usual practice in Wine is to have fewer source files rather than more. I'd suggest merging waylanddrv_main.c and wayland_mutex.c into wayland.c or something along those lines.