Re: svn commit: r1506545 [1/2] - in /subversion/branches/fsfs-improvements/subversion: include/ libsvn_fs_fs/

On Thu, Aug 21, 2014 at 1:17 PM, Branko Čibej <brane_at_wandisco.com> wrote:

> On 21.08.2014 11:33, Branko Čibej wrote:
>
> On 21.08.2014 10:44, Evgeny Kotkov wrote:
>
>
> I am wondering, whether this is a portable way of comparing structs.
>
>
> It is not. The portable way is to use the '==' operator.
>
>
> ... in C++, that is ...
>
> memcmp is not even safe (in general) if the struct is initialized to a
> known value (e.g., with memset to 0), because the compiler is allowed to
> use the struct padding any way it likes; and a function-local struct may
> not even exist on the stack until the memcmp is called, causing the
> compiler to spill its contents onto the stack.
>
> The only really portable way to compare structs is to (recursively)
> compare its members using '=='. That said, I've yet to see a platform where
> memcmp after memset (or calloc) didn't work.
>
>
Changed in r1619358 and 1620602.

Thanks everyone!

-- Stefan^2.
Received on 2014-08-26 15:56:50 CEST