Re: [PATCH 04/10] ARM: ftrace: allow building without frame pointers

Steven Rostedt
2010-02-23T18:03:11Z

On Tue, 2010-02-23 at 23:28 +0530, Rabin Vincent wrote:

> The easiest option to have a more obvious message than a linker error
> would be to add something like this in entry-common.S:
>
> #if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4)) \
> && !defined(OLD_MCOUNT)
> #warning Ftrace on GCC < 4.4 requires frame pointers
> #endif
>
> Messages like this are also present in other places in ARM (for example
> arch/arm/kernel/unwind.c), so this wouldn't be this first.
>
> Note that the above message would help in all cases except the one where
> someone builds the kernel with !fp and GCC 4.4+, and then builds a
> module with an older GCC. That would still be only a linker error.

I was going to recommend the #if above. But shouldn't it be a #error
instead of a #warning?

-- Steve