[avr-libc-dev] Help with __ASSEMBLER__ usage in device header files

[Boyapati, Anitha]

Hi,

Many header files use __ASSEMBLER__ (predefined macro automatically set by gcc 
front end when processing assembly files) to protect some macros. As far as I 
notice, ADC is mostly protected. For e.g., the change introduced in the below 
link does that.
http://svn.savannah.nongnu.org/viewvc/trunk/avr-libc/include/avr/iom8.h?root=avr-libc&r1=274&r2=280

#ifndef __ASSEMBLER__
        #define ADC _SFR_MEM16(...)
#endif

Can someone explain why this is intended only for ADC and that too only for 
some devices? (For e.g., iom32u4.h doesn't have)

Thanks
Anitha