__attribute__ allows you to specify special
attributes of types. Some type attributes apply only to
union types, while others can apply to any type defined
typedef declaration. Other attributes are defined for
functions (see Function Attributes), labels (see Label Attributes), enumerators (see Enumerator Attributes), and for
variables (see Variable Attributes).
__attribute__ keyword is followed by an attribute specification
inside double parentheses.
You may specify type attributes in an enum, struct or union type
declaration or definition by placing them immediately after the
enum keyword. A less preferred
syntax is to place them just past the closing curly brace of the
You can also include type attributes in a
See Attribute Syntax, for details of the exact syntax for using