On Tue, Nov 6, 2012 at 5:28 AM, Rob <[email protected]> wrote: > On Mon, Nov 05, 2012 at 11:19:00PM +0900, Hitoshi Mitake wrote: >> On Mon, Nov 5, 2012 at 11:04 PM, Thomas Preud'homme <[email protected]> >> wrote: >> > Le lundi 5 novembre 2012 14:53:16, Hitoshi Mitake a écrit : >> >> Of course, comparison between different typed structs or structs and >> >> scalar typed values should cause compile error. But I feel that if we >> >> can write comparison between same struct typed values with == >> >> operator, a compiler will be very useful. Because we can avoid the >> >> possibility of passing wrong value as 3rd parameter of memcmp(). >> > >> > memcmp is not what you want because if a structure contains padding you are >> > not sure of its content. Therefore two structures could be identical with >> > different content inside the padding. You must compare field by field. >> > That's why >> > assignement is possible but not equality: assignment is ok because you can >> > copy the padding so memcpy will give a valid copy of the structure. >> > Comparing >> > with memcpy on the other hand will return false for some equal structures. >> >> Ah, I missed about the padding... As you say, memcmp() is not a stuff for the >> above situation. > > I had never thought of that, interesting edge case. > > >> >> The standard of C doesn't allow this behaviour. But I think it may be >> >> worth implementing it on TCC. Can TCC accept this behaviour as >> >> implementation specific dialect? >> > >> > From http://bellard.org/tcc/ : >> > >> > UNLIMITED! Any C dynamic library can be used directly. TCC is heading >> > torward >> > full ISOC99 compliance. TCC can of course compile itself. >> > >> > I don't think we should not follow C99 on this. >> > >> >> OK, I understand the direction of TCC. >> I'll implement == for field by field comparison only for my toy if I'll do :) >> >> Thanks, > > Regardless, I'd be interested in seeing your branch of tcc if you have it > hosted anywhere? >
Thanks for your interest :) I'm hosting my tcc here, and I'll push the change to this branch: https://github.com/mitake/tinycc/tree/struct-cmp I've not implemented the feature yet, but my work in progress will appear here. Thanks, -- Hitoshi Mitake [email protected] _______________________________________________ Tinycc-devel mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/tinycc-devel
