[PATCH 01/13] kconfig: add IS_PROPER helper

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

We depend on -ffunction-sections -fdata-sections at a lot of places and
fail the link without due to undefined references. This is especially
needed for obj-pbl-y code as the files usually have other functions
depending on barebox proper infrastructure, but that is never called.

This works so far, but breaks for two things: LTO and using PBL on
sandbox. Both I have not managed to get the linker not to complain about
the undefined references in the ultimately unreferenced code.

Therefore, let's solve this a different way: Add an IS_PROPER macro and
have the stubs defined when !IS_PROPER.

This has the nice side effect of compile testing the stubs during PBL
build, so forgotten semicolons are more likely to be noticed during
development instead of CI run.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 include/linux/kconfig.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index 58f68adbbadf..8d31584c0c2a 100644
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -33,4 +33,14 @@
  */
 #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
 
+/*
+ * IS_PROPER(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', or 'm'
+ * and file is being compiled for barebox proper, 0 otherwise.
+ */
+#ifndef __PBL__
+#define IS_PROPER(option) IS_ENABLED(option)
+#else
+#define IS_PROPER(option) 0
+#endif
+
 #endif /* __LINUX_KCONFIG_H */
-- 
2.39.5