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