Support SINGLE SHARED attributes of DATA

[KO Myung-Hun]

Hi/2.

emxomfld(wlink) and ld does not support SINGLE SHARED attributes of DATA.

[KO Myung-Hun]

patch for single shared

[bird]

That's on purpose as it doesn't mix with how libc works (forking and more). Unless you present me with a very convincing use case, I'm not going to help users mess up their program/DLLs by making their data segment shared.

[KO Myung-Hun]

First of all, LINK386, VAC308 and VAC365 support this. And sometimes global data structure acrossing processes is needed. Of course, it can be achived by a shared memory. But a shared memory requires additional work, and memory usage is not efficient. For 1 bytes, at least 4KB is used. Worse 64KB.

[bird]

Seems you've got clue what implications having a shared data section in a DLL linked against kLibC (specifically, including dll0.o) will have. Which is exactly why I do not want to expose this feature.

If you need it and know what you're doing, you'll easily find you way around it (hint: #252 will make this easier once implemented).

[KO Myung-Hun]

The eaiest way is to use LINK386, VAC308 or VAC365 linker.

[bird]

Wrong. You put the data you wish to share in a separate segment.

[KO Myung-Hun]

IBM linkers already support .DEF completely.