4.3.10 Attributes

The compiler keyword __attribute__() allows you to specify special attributes of objects or structure fields. Place inside the parentheses following this keyword a comma-separated list of the relevant attributes, for example:

__attribute__((unused))

The attribute can be placed anywhere in the object’s definition, but is usually placed as in the following examples.

char __attribute__((weak)) input;
char input __attribute__((weak));