Jeroen,
commit fb8ffd7cfc68b3dc44e182356a207d784cb30b34 "compiler*.h: sync include/linux/compiler*.h with Linux 3.16" undid the changes of 7ea50d52849fe8ffa5b5b74c979b60b1045d6fc9 "compiler_gcc: do not redefine __gnu_attributes". Add the checks back whether these macro's are already defined (as it causes a lot of noise on e.g. FreeBSD where these defines are already in cdefs.h)
As the original patch this checkpatch warning is ignored: "WARNING: Adding new packed members is to be done with care"
Strange.
Which source files include cdefs.h?
For building u-boot images, sources should only include headers in the u-boot source tree. The standard system headers should not be used except only a few files such as <stdarg.h>.
This is the same as Linux Kernel.
On the contrary, host programs are allowed to use standard system headers such as <stdio.h>, <stdlib.h> etc, where <linux/compiler.h> should not be included.
The root cause of warnings is _not_ that __packed and __weak are always defined in compiler-gcc.h.
I believe the real problem is there are some source files include both system headers and <linux/compiler.h> at the same time.
Best Regards Masahiro Yamada