Re: include/linux/kernel.h:860:32: error: dereferencing pointer to incomplete type 'struct clock_event_device'

[Ian Abbott <abbotti@mev.co.uk>]

On 16/07/17 04:24, kbuild test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   5771a8c08880cdca3bfb4a3fc6d309d6bba20877
> commit: c7acec713d14c6ce8a20154f9dfda258d6bcad3b kernel.h: handle pointers to arrays better in container_of()
> date:   3 days ago
> config: ia64-allyesconfig (attached as .config)
> compiler: ia64-linux-gcc (GCC) 6.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         git checkout c7acec713d14c6ce8a20154f9dfda258d6bcad3b
>         # save the attached .config to linux build tree
>         make.cross ARCH=ia64
>
> All errors (new ones prefixed by >>):
>
>    In file included from drivers/clocksource/timer-of.c:25:0:
>    drivers/clocksource/timer-of.h:35:28: error: field 'clkevt' has incomplete type
>      struct clock_event_device clkevt;
>                                ^~~~~~
>    In file included from include/linux/err.h:4:0,
>                     from include/linux/clk.h:15,
>                     from drivers/clocksource/timer-of.c:18:
>    drivers/clocksource/timer-of.h: In function 'to_timer_of':
>>> include/linux/kernel.h:860:32: error: dereferencing pointer to incomplete type 'struct clock_event_device'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>                                    ^~~~~~
>    include/linux/compiler.h:517:19: note: in definition of macro '__compiletime_assert'
>       bool __cond = !(condition);    \
>                       ^~~~~~~~~
>    include/linux/compiler.h:537:2: note: in expansion of macro '_compiletime_assert'
>      _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
>      ^~~~~~~~~~~~~~~~~~~
>    include/linux/build_bug.h:46:37: note: in expansion of macro 'compiletime_assert'
>     #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>                                         ^~~~~~~~~~~~~~~~~~
>    include/linux/kernel.h:860:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>      ^~~~~~~~~~~~~~~~
>    include/linux/kernel.h:860:20: note: in expansion of macro '__same_type'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>                        ^~~~~~~~~~~
>    drivers/clocksource/timer-of.h:44:9: note: in expansion of macro 'container_of'
>      return container_of(clkevt, struct timer_of, clkevt);
>             ^~~~~~~~~~~~
> --
>    In file included from drivers//clocksource/timer-of.c:25:0:
>    drivers//clocksource/timer-of.h:35:28: error: field 'clkevt' has incomplete type
>      struct clock_event_device clkevt;
>                                ^~~~~~
>    In file included from include/linux/err.h:4:0,
>                     from include/linux/clk.h:15,
>                     from drivers//clocksource/timer-of.c:18:
>    drivers//clocksource/timer-of.h: In function 'to_timer_of':
>>> include/linux/kernel.h:860:32: error: dereferencing pointer to incomplete type 'struct clock_event_device'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>                                    ^~~~~~
>    include/linux/compiler.h:517:19: note: in definition of macro '__compiletime_assert'
>       bool __cond = !(condition);    \
>                       ^~~~~~~~~
>    include/linux/compiler.h:537:2: note: in expansion of macro '_compiletime_assert'
>      _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
>      ^~~~~~~~~~~~~~~~~~~
>    include/linux/build_bug.h:46:37: note: in expansion of macro 'compiletime_assert'
>     #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>                                         ^~~~~~~~~~~~~~~~~~
>    include/linux/kernel.h:860:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>      ^~~~~~~~~~~~~~~~
>    include/linux/kernel.h:860:20: note: in expansion of macro '__same_type'
>      BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
>                        ^~~~~~~~~~~
>    drivers//clocksource/timer-of.h:44:9: note: in expansion of macro 'container_of'
>      return container_of(clkevt, struct timer_of, clkevt);
>             ^~~~~~~~~~~~
>
> vim +860 include/linux/kernel.h
>
>    843	
>    844	
>    845	/*
>    846	 * swap - swap value of @a and @b
>    847	 */
>    848	#define swap(a, b) \
>    849		do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
>    850	
>    851	/**
>    852	 * container_of - cast a member of a structure out to the containing structure
>    853	 * @ptr:	the pointer to the member.
>    854	 * @type:	the type of the container struct this is embedded in.
>    855	 * @member:	the name of the member within the struct.
>    856	 *
>    857	 */
>    858	#define container_of(ptr, type, member) ({				\
>    859		void *__mptr = (void *)(ptr);					\
>  > 860		BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&	\
>    861				 !__same_type(*(ptr), void),			\
>    862				 "pointer type mismatch in container_of()");	\
>    863		((type *)(__mptr - offsetof(type, member))); })
>    864	
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
>

struct clock_event_device is only completely defined when 
CONFIG_GENERIC_CLOCKEVENTS is defined, which it isn't.  But I'm confused 
as to why TIMER_OF getting selected by allyesconfig since it depends on 
GENERIC_CLOCKEVENTS.

-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti@mev.co.uk> )=-
-=(                          Web: http://www.mev.co.uk/  )=-