From 4cb05a7e8af61822fb9b3627566f41ff38506e4d Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Sun, 23 Jan 2011 18:54:42 +0100
Subject: [PATCH] maint.mk: add syntax-check rule: detect unnecessary #include
 <stddef.h>

* top/maint.mk (sc_prohibit_stddef_without_use): New rule.
---
 ChangeLog    | 5 +++++
 top/maint.mk | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 5425c6616..bba6c3531 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-01-23  Jim Meyering  <meyering@redhat.com>
+
+	maint.mk: add syntax-check rule: detect unnecessary #include <stddef.h>
+	* top/maint.mk (sc_prohibit_stddef_without_use): New rule.
+
 2011-01-23  Bruno Haible  <bruno@clisp.org>
 
 	get-rusage-as: Fix bug.
diff --git a/top/maint.mk b/top/maint.mk
index 5915814c1..606d42ed1 100644
--- a/top/maint.mk
+++ b/top/maint.mk
@@ -571,6 +571,13 @@ sc_prohibit_intprops_without_use:
 	re='\<($(_intprops_syms_re)) *\('				\
 	  $(_sc_header_without_use)
 
+_stddef_syms_re = NULL|offsetof|ptrdiff_t|size_t|wchar_t
+# Prohibit the inclusion of stddef.h without an actual use.
+sc_prohibit_stddef_without_use:
+	@h='<stddef.h>'							\
+	re='\<($(_stddef_syms_re)) *\('					\
+	  $(_sc_header_without_use)
+
 sc_obsolete_symbols:
 	@prohibit='\<(HAVE''_FCNTL_H|O''_NDELAY)\>'			\
 	halt='do not use HAVE''_FCNTL_H or O'_NDELAY			\
-- 
2.11.0