* Packed struct size issue
@ 2019-07-17 13:42 John Levon
2019-07-18 10:16 ` Dan Carpenter
2019-07-18 10:50 ` Dan Carpenter
0 siblings, 2 replies; 3+ messages in thread
From: John Levon @ 2019-07-17 13:42 UTC (permalink / raw)
To: smatch; +Cc: andy
Andy Fiddaman discovered:
$ cat ./test.c
#include <stdio.h>
#include <stdint.h>
struct t1 {
uint8_t critical_warning;
uint16_t temperature;
uint8_t available_spare;
} __packed;
_Static_assert(sizeof(struct t1) == 4, "bad size for t1");
struct t2 {
uint8_t critical_warning;
uint16_t temperature;
uint8_t available_spare;
};
_Static_assert(sizeof(struct t2) == 6, "bad size for t2");
$ ./smatch ./test.c
./test.c:10:34: error: static assertion failed: "bad size for t1"
Looks like we lost this commit:
https://github.com/illumos/smatch/commit/0c60237e4096b7576f0aec21a7545026c7041611#diff-0cd054d23ed9e02274eaa540fc7e6536
??
This works:
https://github.com/citrus-it/illumos-omnios/commit/88e29e1705a616695ec6f905c3cab1f600e12659?diff=unified
regards
john
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Packed struct size issue
2019-07-17 13:42 Packed struct size issue John Levon
@ 2019-07-18 10:16 ` Dan Carpenter
2019-07-18 10:50 ` Dan Carpenter
1 sibling, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2019-07-18 10:16 UTC (permalink / raw)
To: John Levon; +Cc: smatch, andy, sparse
On Wed, Jul 17, 2019 at 02:42:34PM +0100, John Levon wrote:
>
> Andy Fiddaman discovered:
>
> $ cat ./test.c
> #include <stdio.h>
> #include <stdint.h>
>
> struct t1 {
> uint8_t critical_warning;
> uint16_t temperature;
> uint8_t available_spare;
> } __packed;
>
> _Static_assert(sizeof(struct t1) == 4, "bad size for t1");
>
I've added Sparse mailing list to the CC.
It looks like the packed attribute is broken on upstream Sparse (from
April) as well and I would prefer if they fixed it and I pulled in their
fix. It's probably better to use __attribute__((packed)) instead of the
__packed macro in the test code.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Packed struct size issue
2019-07-17 13:42 Packed struct size issue John Levon
2019-07-18 10:16 ` Dan Carpenter
@ 2019-07-18 10:50 ` Dan Carpenter
1 sibling, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2019-07-18 10:50 UTC (permalink / raw)
To: John Levon; +Cc: smatch, andy, linux-sparse
[ resending to the correct Sparse email address ].
On Wed, Jul 17, 2019 at 02:42:34PM +0100, John Levon wrote:
>
> Andy Fiddaman discovered:
>
> $ cat ./test.c
> #include <stdio.h>
> #include <stdint.h>
>
> struct t1 {
> uint8_t critical_warning;
> uint16_t temperature;
> uint8_t available_spare;
> } __packed;
>
> _Static_assert(sizeof(struct t1) == 4, "bad size for t1");
>
I've added Sparse mailing list to the CC.
It looks like the packed attribute is broken on upstream Sparse (from
April) as well and I would prefer if they fixed it and I pulled in their
fix. It's probably better to use __attribute__((packed)) instead of the
__packed macro in the test code.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-07-18 10:51 UTC | newest]
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2019-07-17 13:42 Packed struct size issue John Levon
2019-07-18 10:16 ` Dan Carpenter
2019-07-18 10:50 ` Dan Carpenter
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