Hi Joppuh,
I do not think your problem is not OSX.
In my opinion, there are two possibilities :
Either you forgot one of the 3 defines :
SAM3X8E
USB_PID=0x003E
USBCON
Either you forgot an include path or one or more files are missing.
Warning, and include Defines Path must be set in the configuration C and C+ + (Tool Settings) :
ARM Sourcery Windows GCC C Compiler
and
ARM Sourcery Windows GCC C + + Compiler
Let me known please.
Nassa.