Re: [PATCH 2/4] packet: Offset plus length is not always uint32_t, but it's always size_t

On Thu, 30 Nov 2023 11:18:48 +1100 David Gibson wrote:

On Wed, Nov 29, 2023 at 02:46:08PM +0100, Stefano Brivio wrote:

...

According to gcc, PRIu32 matches the type of the argument we're printing here on both 64 and 32-bits architectures. According to Clang, though, that's not the case, as the result of the sum is an unsigned long on 64-bit.

Use the z modifier, given that we're summing uint32_t to size_t, and the result is at most promoted to size_t.

Heh, sorry, obviously hadn't read this patch when I commented on this spot in the first one. The problem here is that the final promoted type depends on whether size_t is wider than uint32_t or not, which can vary with architecture.

That said, I doubt we're likely to support anything with a size_t strictly *less* than 32-bits, so %zu is probably safe.

...

Signed-off-by: Stefano Brivio --- packet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packet.c b/packet.c index 12ac76b..ccfc846 100644 --- a/packet.c +++ b/packet.c @@ -106,7 +106,7 @@ void *packet_get_do(const struct pool *p, size_t idx, size_t offset,

if (p->pkt[idx].offset + len + offset > p->buf_size) { if (func) { - trace("packet offset plus length %lu from size %zu, " + trace("packet offset plus length %zu from size %zu, " "%s:%i", p->pkt[idx].offset + len + offset, p->buf_size, func, line); }