+@node UNUSED NO_RETURN NO_INLINE PRINTF_FORMAT
+@section UNUSED, NO_RETURN, NO_INLINE, and PRINTF_FORMAT
+
+These macros defined in @file{<debug.h>} tell the compiler special
+attributes of a function or function parameter. Their expansions are
+GCC-specific.
+
+@defmac UNUSED
+Appended to a function parameter to tell the compiler that the
+parameter might not be used within the function. It suppresses the
+warning that would otherwise appear.
+@end defmac
+
+@defmac NO_RETURN
+Appended to a function prototype to tell the compiler that the
+function never returns. It allows the compiler to fine-tune its
+warnings and its code generation.
+@end defmac
+
+@defmac NO_INLINE
+Appended to a function prototype to tell the compiler to never emit
+the function in-line. Occasionally useful to improve the quality of
+backtraces (see below).
+@end defmac
+
+@defmac PRINTF_FORMAT (@var{format}, @var{first})
+Appended to a function prototype to tell the compiler that the
+function takes a @func{printf}-like format string as its
+@var{format}th argument and that the corresponding value arguments
+start at the @var{first}th argument. This lets the compiler tell you
+if you pass the wrong argument types.
+@end defmac
+