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| author | David Daney <ddaney@caviumnetworks.com> | 2008-11-20 17:26:36 -0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2008-11-24 16:35:07 +0000 |
| commit | 8ec2e24356e63dc298c6040557faf396410907ac (patch) | |
| tree | 77615c090cec2a726a31618e66aaac7dd10a33b1 /arch/mips | |
| parent | ed313489badef16d700f5a3be50e8fd8f8294bc8 (diff) | |
| download | blackbird-op-linux-8ec2e24356e63dc298c6040557faf396410907ac.tar.gz blackbird-op-linux-8ec2e24356e63dc298c6040557faf396410907ac.zip | |
MIPS: Make BUG() __noreturn.
Often we do things like put BUG() in the default clause of a case
statement. Since it was not declared __noreturn, this could sometimes
lead to bogus compiler warnings that variables were used
uninitialized.
There is a small problem in that we have to put a magic while(1); loop to
fool GCC into really thinking it is noreturn. This makes the new
BUG() function 3 instructions long instead of just 1, but I think it
is worth it as it is now unnecessary to do extra work to silence the
'used uninitialized' warnings.
I also re-wrote BUG_ON so that if it is given a constant condition, it
just does BUG() instead of loading a constant value in to a register
and testing it.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/include/asm/bug.h | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/arch/mips/include/asm/bug.h b/arch/mips/include/asm/bug.h index 7eb63de808bc..08ea46863fe5 100644 --- a/arch/mips/include/asm/bug.h +++ b/arch/mips/include/asm/bug.h @@ -7,20 +7,31 @@ #include <asm/break.h> -#define BUG() \ -do { \ - __asm__ __volatile__("break %0" : : "i" (BRK_BUG)); \ -} while (0) +static inline void __noreturn BUG(void) +{ + __asm__ __volatile__("break %0" : : "i" (BRK_BUG)); + /* Fool GCC into thinking the function doesn't return. */ + while (1) + ; +} #define HAVE_ARCH_BUG #if (_MIPS_ISA > _MIPS_ISA_MIPS1) -#define BUG_ON(condition) \ -do { \ - __asm__ __volatile__("tne $0, %0, %1" \ - : : "r" (condition), "i" (BRK_BUG)); \ -} while (0) +static inline void __BUG_ON(unsigned long condition) +{ + if (__builtin_constant_p(condition)) { + if (condition) + BUG(); + else + return; + } + __asm__ __volatile__("tne $0, %0, %1" + : : "r" (condition), "i" (BRK_BUG)); +} + +#define BUG_ON(C) __BUG_ON((unsigned long)(C)) #define HAVE_ARCH_BUG_ON |
