When building swinput 0.7.4 on Ubuntu 12.04 with gcc 4.6.3 on Kernel 3.3.6, I get the following output:

cd src && make -C /lib/modules/3.3.6/build SUBDIRS=/usr/local/src/swinput-0.7.4/src modules
make[1]: Entering directory `/usr/src/linux-3.3.6'
  CC [M]  /usr/local/src/swinput-0.7.4/src/swinput.o
/usr/local/src/swinput-0.7.4/src/swinput.c: In function 'logger':
/usr/local/src/swinput-0.7.4/src/swinput.c:52:2: error: invalid initializer
make[2]: * [/usr/local/src/swinput-0.7.4/src/swinput.o] Error 1
make[1]: * [_module_/usr/local/src/swinput-0.7.4/src] Error 2
make[1]: Leaving directory `/usr/src/linux-3.3.6'
make: * [default] Error 2

The line mentioned says: "va_list ap = NULL;" which is, to my very, very limited understanding of C, a strange line (assigning a pointer value to a non-pointer variable). Removing the "=NULL" part fixes the error and lets swinput compile but I do not know what other effects that might have.