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__cat and __unique_id in stringify.h

PATCH In review Rusty Russell 2 participants 2 messages Jun 12, 2003 Module support

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Rusty Russell

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PATCH 1/1 __cat and __unique_id in stringify.h

__cat() to paste tokens could be used in a few places, and __unique_id() is useful for module.h.

Linus, please apply,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: Centralize token pasting and generation of unique IDs
Author: Rusty Russell
Status: Tested on 2.5.70-bk13

D: Add __cat(a,b) to implement token pasting to stringify.h. To
D: generate unique names, __unique_id(stem) is implemented (it'd be
D: nice to have a gcc extension to give a unique identifier). Change
D: module.h to use them.

include/linux/module.h +1 -3
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26569-linux-2.5.70-bk16/include/linux/module.h .26569-linux-2.5.70-bk16.updated/include/linux/module.h
@@ -55,10 +55,8 @@ search_extable(const struct exception_ta
 	       unsigned long value);
 
 #ifdef MODULE
-#define ___module_cat(a,b) __mod_ ## a ## b
-#define __module_cat(a,b) ___module_cat(a,b)
 #define __MODULE_INFO(tag, name, info)					  \
-static const char __module_cat(name,__LINE__)[]				  \
+static const char __unique_id(name)[]					  \
   __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
 
 #define MODULE_GENERIC_TABLE(gtype,name)			\
include/linux/stringify.h +7 -0
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26569-linux-2.5.70-bk16/include/linux/stringify.h .26569-linux-2.5.70-bk16.updated/include/linux/stringify.h
@@ -9,4 +9,11 @@
 #define __stringify_1(x)	#x
 #define __stringify(x)		__stringify_1(x)
 
+/* Paste two tokens together. */
+#define ___cat(a,b) a ## b
+#define __cat(a,b) ___cat(a,b)
+
+/* Try to give a unique identifier: this comes close, iff used as static. */
+#define __unique_id(stem) \
+	__cat(__cat(__uniq,stem),__cat(__LINE__,KBUILD_BASENAME))
 #endif	/* !__LINUX_STRINGIFY_H */
#1 lore raw

include/linux/stringify.h line 14

Quoted 3 lines · Rusty Russell
include/linux/stringify.h +3 -0
+/* Paste two tokens together. */
+#define ___cat(a,b) a ## b
+#define __cat(a,b) ___cat(a,b)

It might be a bit too easy to type ___cat instead of __cat. If you use ___cat___ or something similar, there might be less problems caused by typing problems.

Jörn

Signature · 3 lines
With a PC, I always felt limited by the software available. On Unix, 
I am limited only by my knowledge.
-- Peter J. Schoenster