On Wed, 2011-08-31 at 18:47 -0400, Nicolas Pitre wrote:

On Tue, 30 Aug 2011, Tixy wrote:

[...]

quoted

When ARM_KPROBES_TEST_MODULE is configured for a stand-alone module,
rather than built-in, then

#ifdef CONFIG_ARM_KPROBES_TEST_MODULE

is false.

OK... It seems that, when you have a tristate config symbol FOOBAR, if 
CONFIG_FOOBAR=y then the CONFIG_FOOBAR preprocessor symbol is defined.  
If you have CONFIG_FOOBAR=m then the CONFIG_FOOBAR_MODULE preprocessor 
symbol is defined.

That's useful to know.

In your example above you would end up with 
CONFIG_ARM_KPROBES_TEST_MODULE_MODULE being defined.

quoted

I found other examples where people seemed to have gotten around this 
by selecting a second config symbol and copied that. E.g. 
FTRACE_STARTUP_TEST selects FTRACE_SELFTEST which is then used in 
#ifdef statements.

Is there a better way? If not, I should explain this anyway in the
changelog.

What I'd suggest is that you have:

config ARM_KPROBES_TEST
	tristate ...

And then you may use this in the code:

#ifdef CONFIG_ARM_KPROBES_TEST_MODULE
EXPORT_SYMBOL_GPL(...);
#endif

so those symbols are only exported when necessary.

Yep, that works and is a lot cleaner, thanks.

I've also made the extern declarations for these exported symbols
unconditional in kprobes-test.h. It didn't seem worth trying to #ifdef
them to only exist when the test code is configured (like I was trying
to do in "[PATCH 06/10] ARM: kprobes: Add exports for test code").

-- 
Tixy