library header files in case they are included into files that have
redefined the base name of the attribute as a preprocessor macro.
+GCC also accepts the keyword @code{__attribute} as a synonym for
+@code{__attribute__}.
+
Some function attributes take one or more arguments that refer to
the function's parameters by their positions within the function parameter
list. Such attribute arguments are referred to as @dfn{positional arguments}.
being concerned about a possible macro of the same name. For example,
you may use the attribute name @code{__noreturn__} instead of @code{noreturn}.
+GCC also accepts the keyword @code{__attribute} as a synonym for
+@code{__attribute__}.
@subsubheading Label Attributes