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SubjectRe: 2.6.14 assorted warnings
On Sun, Oct 30, 2005 at 10:15:31PM +0000, Alan Cox wrote:
> gcc is a *LOT* smarter than you give it credit for. It will not warn for
> cases where it isn't able to tell how foo is used passed with &foo. It
> will warn for cases where it can
static inline __attribute__((always_inline)) int bar(int n, int *idx)
{
if (n != 1)
return 0;
*idx = 1;
return 1;
}
void baz(int *v, int n)
{
int idx;
int p = bar(n, &idx);
if (__builtin_expect(!p, 0))
return;
*v |= idx;
}
and try gcc -Wall on that. Watch it warn about idx being possibly
uninitialized. Replace __builtin_expect(!p, 0) with !p and see
the warning go away. That, BTW, is a trimmed-down source of bogus
warning in bio.c. And a lot of its analogs all over the tree.
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