[swift-dev] swift (ABI) and Windows

[Joe Groff]

> On May 5, 2016, at 4:18 PM, Sangjin Han via swift-dev <swift-dev at swift.org> wrote:
> 
> Hi,
> 
> I made an experimental MSVC port. Of cause, dllimport/dllexport and the driver for linking and many other part is not implemented. But dynamic linking was possible with some trick.
> 
> I think it is useful for designing, my observation about the experimental building of libswiftCore.dll, libswiftSwiftOnoneSupport.dll and linking of Hello.exe - its source has only 'print("Hello")'.
> 
> 1) SWIFT_RUNTIME_EXPORT was not enough for dllexport.
>   Hello.obj needed defined in libswift*.dll
>     _swift_getExistentialTypeMetadata,
>     _TFs5printFTGSaP__9separatorSS10terminatorSS_T_,
>     _TMSS,
>     _TZvOs7Process5_argcVs5Int32,
>     swift_bufferAllocate, .... 
>   Some of above are dllexported by the macro, but _T* are not. Maybe, it generated by swiftc.exe.
>   I used the utility 'dlltool.exe' from Cygwin/MinGW world. It extracts all symbols and generates 'allsymbol.def'.
>   With that .def, I could build the all-symbol-dllexported libswiftCore.dll.
>   (I'm hoping we can build it without this trick.)

The _T symbols are emitted by the Swift compiler. You should modify swiftc's IRGen to generate public symbols with LLVM's "dllexport" storage class when targeting Windows.

-Joe