extend.texi (Constructing Calls): Add warning about the limitations of the functions.

	* doc/extend.texi (Constructing Calls): Add warning about
	the limitations of the functions.

From-SVN: r74314

gcc/ChangeLog

 2003-12-05  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	* doc/extend.texi (Constructing Calls): Add warning about
+	the limitations of the functions.
+
+2003-12-05  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	PR middle-end/11151
 	* function.h (struct function): New field 'x_naked_return_label'.
 	* function.c (free_after_compilation): Set it to NULL.

gcc/doc/extend.texi

@@ -884,6 +884,11 @@ and later return that value, without knowing what data type
 the function tried to return (as long as your caller expects
 that data type).
 
+However, these built-in functions may interact badly with some
+sophisticated features or other extensions of the language.  It
+is, therefore, not recommended to use them outside very simple
+functions acting as mere forwarders for their arguments.
+
 @deftypefn {Built-in Function} {void *} __builtin_apply_args ()
 This built-in function returns a pointer to data
 describing how to perform a call with the same arguments as were passed