Re: [PATCH] MIPS: prevent compiler warning from cop2_{save,restore}

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello.

On 9/25/2014 1:26 PM, Paul Burton wrote:

The no-op cases of cop2_save & cop2_restore lead to the following
warnings being emitted during build with recent versions of gcc (tested
using gcc 4.8.3 from the Mentor Sourcery CodeBench 2014.05 toolchain):

   In file included from ./arch/mips/include/asm/switch_to.h:18:0,
                    from kernel/sched/core.c:78:
   kernel/sched/core.c: In function 'finish_task_switch':
   include/asm-generic/current.h:6:45: warning: value computed is not used [-Wunused-value]
    #define get_current() (current_thread_info()->task)
                                                ^
   ./arch/mips/include/asm/cop2.h:48:32: note: in definition of macro 'cop2_restore'
    #define cop2_restore(r)  do { (r); } while (0)
                                   ^
   include/asm-generic/current.h:7:17: note: in expansion of macro 'get_current'
    #define current get_current()
                    ^
   ./arch/mips/include/asm/switch_to.h:114:16: note: in expansion of macro 'current'
      cop2_restore(current);     \
                   ^
   kernel/sched/core.c:2225:2: note: in expansion of macro 'finish_arch_switch'
     finish_arch_switch(prev);
     ^

Avoid the warning by "using" the value by casting to void.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
  arch/mips/include/asm/cop2.h | 8 ++++----
  1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/cop2.h b/arch/mips/include/asm/cop2.h
index 51f80bd..63b3468 100644
--- a/arch/mips/include/asm/cop2.h
+++ b/arch/mips/include/asm/cop2.h
@@ -37,15 +37,15 @@ extern void nlm_cop2_restore(struct nlm_cop2_state *);

  #define cop2_present		1
  #define cop2_lazy_restore	1
-#define cop2_save(r)		do { (r); } while (0)
-#define cop2_restore(r)		do { (r); } while (0)
+#define cop2_save(r)		do { (void)(r); } while (0)
+#define cop2_restore(r)		do { (void)(r); } while (0)

  #else

  #define cop2_present		0
  #define cop2_lazy_restore	0
-#define cop2_save(r)		do { (r); } while (0)
-#define cop2_restore(r)		do { (r); } while (0)
+#define cop2_save(r)		do { (void)(r); } while (0)
+#define cop2_restore(r)		do { (void)(r); } while (0)
  #endif

Looks like the definition are identical between 2 arms of #if, so why not move the macro definition out of #if, perhaps in later cleanup patch?

WBR, Sergei






[Index of Archives]     [Linux MIPS Home]     [LKML Archive]     [Linux ARM Kernel]     [Linux ARM]     [Linux]     [Git]     [Yosemite News]     [Linux SCSI]     [Linux Hams]

  Powered by Linux