1 files changed, 5 insertions, 1 deletions

diff --git a/gl/warn-on-use.h b/gl/warn-on-use.h
index 30756034..701013a0 100644
--- a/gl/warn-on-use.h
+++ b/gl/warn-on-use.h
@@ -1,5 +1,5 @@
 /* A C macro for emitting warnings if a function is used.
-   Copyright (C) 2010-2023 Free Software Foundation, Inc.
+   Copyright (C) 2010-2024 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify it
    under the terms of the GNU Lesser General Public License as published
@@ -32,6 +32,10 @@
    _GL_WARN_ON_USE_ATTRIBUTE is for functions with 'static' or 'inline'
    linkage.
 
+   _GL_WARN_ON_USE should not be used more than once for a given function
+   in a given compilation unit (because this may generate a warning even
+   if the function is never called).
+
    However, one of the reasons that a function is a portability trap is
    if it has the wrong signature.  Declaring FUNCTION with a different
    signature in C is a compilation error, so this macro must use the