Wireshark · Wireshark-dev: Re: [Wireshark-dev] size_t under Windows ...

[Graham Bloice <graham.bloice@xxxxxxxxxxxxx>]

On 24 November 2017 at 12:23, Roland Knall <rknall@xxxxxxxxx> wrote:

Not necessarily, in certain variations building WinXP and Win7 can lead to size_t being 4 byte, but the pointer PVOID either 8 byte or 4 byte depending on the target compile environment.

This is incorrect, as noted earlier in the thread by Helge, size_t varies by the cpu target, x86 or x64, not by the OS target.

On x64 size_t is an unsigned __int64 which is self-evidently 64 bits, on x86 it's an unsigned int which is 32 bits.

On Windows this causes issues when assigning a size_t value into an int, which on x64 is a narrowing and will require a cast (if you're absolutely positive the value won't be bigger than an int).

If you use size_t everywhere it should all just work.

 

I would stick with a definition of size_t, because others will have to handle the right size, not us.

cheers

On Fri, Nov 24, 2017 at 11:56 AM, Dario Lombardo <dario.lombardo.ml@xxxxxxxxx> wrote:

Couldn't it be replaced by guint32 then, and the guard removed?

On Fri, Nov 24, 2017 at 10:45 AM, Helge Kruse <Helge.Kruse@xxxxxxx> wrote:

DWORD is a 32 bit unsigned integer.
size_t is platform dependent, 32 bits in 32 bit Windows and 64 bits in
64 bit Windows. I assume this is similar in other OS like Linux.
Therfore you can't replace DWORD by size_t without checking the impact.

Further there is an additional member cap_pipe_buf in the #ifdef(_WIN32) branch.

Regards
Helge

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Graham Bloice