From: Johann Felix Soden <[email protected]>
kernel/timeconst.pl generates only long sized constants in timeconst.pl
which gives this warning:
kernel/time.c: In function 'msecs_to_jiffies':
kernel/time.c:472: warning: integer constant is too large for 'long' type
unsigned long long is needed.
Signed-off-by: Johann Felix Soden <[email protected]>
CC: H. Peter Anvin <[email protected]>
---
kernel/timeconst.pl | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl
index 62b1287..a645654 100644
--- a/kernel/timeconst.pl
+++ b/kernel/timeconst.pl
@@ -342,12 +342,12 @@ sub output($@)
'USEC_TO_HZ','HZ_TO_USEC') {
foreach $bit (32, 64) {
foreach $suf ('MUL', 'ADJ', 'SHR') {
- printf "#define %-23s %s\n",
+ printf "#define %-23s %sULL\n",
"${pfx}_$suf$bit", shift(@val);
}
}
foreach $suf ('NUM', 'DEN') {
- printf "#define %-23s %s\n",
+ printf "#define %-23s %sULL\n",
"${pfx}_$suf", shift(@val);
}
}
--
1.5.4
Johann Felix Soden wrote:
> From: Johann Felix Soden <[email protected]>
>
> kernel/timeconst.pl generates only long sized constants in timeconst.pl
> which gives this warning:
>
> kernel/time.c: In function 'msecs_to_jiffies':
> kernel/time.c:472: warning: integer constant is too large for 'long' type
>
> unsigned long long is needed.
>
Hm, you've just taken a warning and elevated it to a bug.
According to the C standard, a constant has the shortest type (>= int)
needed to hold the constant, and the warning above is somewhat bogus in
that context (what version of gcc is that, anyway?)
ULL is only appropriate to 32-bit machines, or there will be other
issues downstream. The Right Way[TM] to do this would be to get Linux
to have the [U]INTxx_C() macros from C99.
-hpa
H. Peter Anvin wrote:
> Johann Felix Soden wrote:
> > kernel/timeconst.pl generates only long sized constants in timeconst.pl
> > which gives this warning:
> >
> > kernel/time.c: In function 'msecs_to_jiffies':
> > kernel/time.c:472: warning: integer constant is too large for 'long' type
> >
> > unsigned long long is needed.
> Hm, you've just taken a warning and elevated it to a bug.
>
> According to the C standard, a constant has the shortest type (>= int)
> needed to hold the constant, and the warning above is somewhat bogus in
> that context (what version of gcc is that, anyway?)
>
> ULL is only appropriate to 32-bit machines, or there will be other
> issues downstream. The Right Way[TM] to do this would be to get Linux
> to have the [U]INTxx_C() macros from C99.
>
> -hpa
Sorry for this. Thanks for teaching about the C standard.
About your question: gcc 4.2.3 gave me this warning.
And I'm a little bit surprised because the kernel code is full of
constants with ULL. Is kernel/time.c a special case?
J. F. Soden