On 02/23/10 11:49, Randy Dunlap wrote:
> Hi,
>
> You probably know that sparse produces a ton of errors & warnings when
> run on the Linux kernel tree (a little over 1 MB in my latest 'make C=1'
> on x86_64 arch.).
>
> I'm wondering if all of these are valid.
>
> Examples:
8. There are many cases of sparse "error: bad integer constant expression"
that gcc handles without a problem, when the constant expression uses a
macro or static inline function:
a. drivers/gpu/drm/drm_drv.c:59:9: error: bad integer constant expression
static struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, 0),
b. drivers/media/video/v4l2-ioctl.c:185:10: error: bad integer constant expression
static const char *v4l1_ioctls[] = {
[_IOC_NR(VIDIOCGCAP)] = "VIDIOCGCAP",
};
c. fs/proc/array.c:154:9: error: bad integer constant expression
BUILD_BUG_ON(1 + ilog2(TASK_STATE_MAX) != ARRAY_SIZE(task_state_array));
d. sound/pci/hda/hda_proc.c:422:18: error: bad integer constant expression
static char *names[] = {
[ilog2(AC_PWRST_D0SUP)] = "D0",
};
e. drivers/gpu/drm/drm_ioc32.c:1017:10: error: bad integer constant expression
drm_ioctl_compat_t *drm_compat_ioctls[] = {
[DRM_IOCTL_NR(DRM_IOCTL_VERSION32)] = compat_drm_version,
};
I have a test case for "d." above.
(attached)
> sparse const_sound.c
const_sound.c:114:18: error: bad integer constant expression
--
~Randy
#include <asm-generic/ioctl.h>
static inline __attribute__((const))
int fls(unsigned int n)
{
return 0;
}
static inline __attribute__((const))
int fls64(unsigned int n)
{
return 63;
}
static inline __attribute__((const))
int __ilog2_u32(unsigned int n)
{
return fls(n) - 1;
}
static inline __attribute__((const))
int __ilog2_u64(unsigned long n)
{
return fls64(n) - 1;
}
static inline __attribute__((const))
int ____ilog2_NaN(void)
{
return -1;
}
#define ilog2(n) \
( \
__builtin_constant_p(n) ? ( \
(n) < 1 ? ____ilog2_NaN() : \
(n) & (1ULL << 63) ? 63 : \
(n) & (1ULL << 62) ? 62 : \
(n) & (1ULL << 61) ? 61 : \
(n) & (1ULL << 60) ? 60 : \
(n) & (1ULL << 59) ? 59 : \
(n) & (1ULL << 58) ? 58 : \
(n) & (1ULL << 57) ? 57 : \
(n) & (1ULL << 56) ? 56 : \
(n) & (1ULL << 55) ? 55 : \
(n) & (1ULL << 54) ? 54 : \
(n) & (1ULL << 53) ? 53 : \
(n) & (1ULL << 52) ? 52 : \
(n) & (1ULL << 51) ? 51 : \
(n) & (1ULL << 50) ? 50 : \
(n) & (1ULL << 49) ? 49 : \
(n) & (1ULL << 48) ? 48 : \
(n) & (1ULL << 47) ? 47 : \
(n) & (1ULL << 46) ? 46 : \
(n) & (1ULL << 45) ? 45 : \
(n) & (1ULL << 44) ? 44 : \
(n) & (1ULL << 43) ? 43 : \
(n) & (1ULL << 42) ? 42 : \
(n) & (1ULL << 41) ? 41 : \
(n) & (1ULL << 40) ? 40 : \
(n) & (1ULL << 39) ? 39 : \
(n) & (1ULL << 38) ? 38 : \
(n) & (1ULL << 37) ? 37 : \
(n) & (1ULL << 36) ? 36 : \
(n) & (1ULL << 35) ? 35 : \
(n) & (1ULL << 34) ? 34 : \
(n) & (1ULL << 33) ? 33 : \
(n) & (1ULL << 32) ? 32 : \
(n) & (1ULL << 31) ? 31 : \
(n) & (1ULL << 30) ? 30 : \
(n) & (1ULL << 29) ? 29 : \
(n) & (1ULL << 28) ? 28 : \
(n) & (1ULL << 27) ? 27 : \
(n) & (1ULL << 26) ? 26 : \
(n) & (1ULL << 25) ? 25 : \
(n) & (1ULL << 24) ? 24 : \
(n) & (1ULL << 23) ? 23 : \
(n) & (1ULL << 22) ? 22 : \
(n) & (1ULL << 21) ? 21 : \
(n) & (1ULL << 20) ? 20 : \
(n) & (1ULL << 19) ? 19 : \
(n) & (1ULL << 18) ? 18 : \
(n) & (1ULL << 17) ? 17 : \
(n) & (1ULL << 16) ? 16 : \
(n) & (1ULL << 15) ? 15 : \
(n) & (1ULL << 14) ? 14 : \
(n) & (1ULL << 13) ? 13 : \
(n) & (1ULL << 12) ? 12 : \
(n) & (1ULL << 11) ? 11 : \
(n) & (1ULL << 10) ? 10 : \
(n) & (1ULL << 9) ? 9 : \
(n) & (1ULL << 8) ? 8 : \
(n) & (1ULL << 7) ? 7 : \
(n) & (1ULL << 6) ? 6 : \
(n) & (1ULL << 5) ? 5 : \
(n) & (1ULL << 4) ? 4 : \
(n) & (1ULL << 3) ? 3 : \
(n) & (1ULL << 2) ? 2 : \
(n) & (1ULL << 1) ? 1 : \
(n) & (1ULL << 0) ? 0 : \
____ilog2_NaN() \
) : \
(sizeof(n) <= 4) ? \
__ilog2_u32(n) : \
__ilog2_u64(n) \
)
// d. sound/pci/hda/hda_proc.c:422:18: error: bad integer constant expression
#define AC_PWRST_D0SUP (1<<0)
static char *names[] = {
[ilog2(AC_PWRST_D0SUP)] = "D0",
};
int main(int argc, char *argv[])
{
}
