Avoid some autoconf warnings.

[gnulib.git] / m4 / absolute-header.m4

diff --git a/m4/absolute-header.m4 b/m4/absolute-header.m4
index 5b7a2fc..e039f0c 100644 (file)
--- a/m4/absolute-header.m4
+++ b/m4/absolute-header.m4
@@ -1,5 +1,5 @@
-# absolute-header.m4 serial 7
-dnl Copyright (C) 2006, 2007 Free Software Foundation, Inc.
+# absolute-header.m4 serial 8
+dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -16,6 +16,9 @@ dnl From Derek Price.
 # The three "///" are to pacify Sun C 5.8, which otherwise would say
 # "warning: #include of /usr/include/... may be non-portable".
 # Use `""', not `<>', so that the /// cannot be confused with a C99 comment.
+# Note: This macro assumes that the header file is not empty after
+# preprocessing, i.e. it does not only define preprocessor macros but also
+# provides some type/enum definitions or function/variable declarations.
 AC_DEFUN([gl_ABSOLUTE_HEADER],
 [AC_LANG_PREPROC_REQUIRE()dnl
 AC_FOREACH([gl_HEADER_NAME], [$1],