From 6f33d58794ef4cef4b2c706029810f9688bd3026 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 22 Nov 2012 12:30:25 +1030 Subject: [PATCH] __UNIQUE_ID() Jan Beulich points out __COUNTER__ (gcc 4.3 and above), so let's use that to create unique ids. This is better than __LINE__ which we use today, so provide a wrapper. Stanislaw Gruszka reported that some module parameters start with a digit, so we need to prepend when we for the unique id. Signed-off-by: Rusty Russell Acked-by: Jan Beulich --- include/linux/compiler-gcc4.h | 2 ++ include/linux/compiler.h | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 412bc6c2b023..56c802cba7f6 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -31,6 +31,8 @@ #define __linktime_error(message) __attribute__((__error__(message))) +#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) + #if __GNUC_MINOR__ >= 5 /* * Mark a position in code as unreachable. This can be used to diff --git a/include/linux/compiler.h b/include/linux/compiler.h index f430e4162f41..5f45335e1ac7 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -42,6 +42,10 @@ extern void __chk_io_ptr(const volatile void __iomem *); # define __rcu #endif +/* Indirect macros required for expanded argument pasting, eg. __LINE__. */ +#define ___PASTE(a,b) a##b +#define __PASTE(a,b) ___PASTE(a,b) + #ifdef __KERNEL__ #ifdef __GNUC__ @@ -164,6 +168,11 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); (typeof(ptr)) (__ptr + (off)); }) #endif +/* Not-quite-unique ID. */ +#ifndef __UNIQUE_ID +# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__) +#endif + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */