diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bf31622a8995..33de7acb422a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-10-18  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	* doc/extend.texi (Attribute Syntax): Clarify details of
+	attributes on parameters.
+
 2004-10-17  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	* tree-ssa-loop-ivopts.c (tree_ssa_iv_optimize): Move checking out of
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index d5236154d428..eef64f193275 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -2424,6 +2424,15 @@ declaration as a whole.  In the obsolescent usage where a type of
 specifiers and qualifiers may be an attribute specifier list with no
 other specifiers or qualifiers.
 
+At present, the first parameter in a function prototype must have some
+type specifier which is not an attribute specifier; this resolves an
+ambiguity in the interpretation of @code{void f(int
+(__attribute__((foo)) x))}, but is subject to change.  At present, if
+the parentheses of a function declarator contain only attributes then
+those attributes are ignored, rather than yielding an error or warning
+or implying a single parameter of type int, but this is subject to
+change.
+
 An attribute specifier list may appear immediately before a declarator
 (other than the first) in a comma-separated list of declarators in a
 declaration of more than one identifier using a single list of