[lwip-devel] [bug #49827] wrong cast to size_t on 16-bit x86 architecture

[Alexander]

Follow-up Comment #7, bug #49827 (project lwip):

I use OpenWatcom compiler and have next line in headers:
typedef int ptrdiff_t;
(source
https://github.com/open-watcom/open-watcom-v2/blob/master/bld/hdr/ptrdifft.sp#L48)

int in my system is 16 bit (intel 80186 clone)
pointer size depends on memory model that I use. 
If I use SMALL memory model, so pointer size is 16 bit (only 16bit offset to
default data segment) and default LWIP_CONST_CAST works in this case.
But SMALL data model allows me to use only 64Kb of data, because of that I
have to use LARGE memory model, where 
pointer size is 32 bit (16 bit offset + 16 bit segment), so in this case (my
default scenario) I need to override LWIP_CONST_CAST.

I think that if I choose HUGE memory model, so ptrdiff_t will be long:
typedef long ptrdiff_t;
but in this case overhead of pointers usage will appear.

I don't know how to write LWIP_CONST_CAST to be more portable to my case.
I have the same problems with other community projects.

I realize that DOS is dead, but not quite dead.


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