[swift-dev] swift (ABI) and Windows

[Joe Groff]

> On May 7, 2016, at 4:01 PM, Sangjin Han <tinysun.net at gmail.com> wrote:
> 
> Hi all,
> 
> I merged Saleem's #2080 to my working branch, and did some experiment.
> 
> I could compile easily Hello.swift with #2080 merged one.
> 
>   swiftc -c -o Hello.obj Hello.swift
>   clang -o Hello.exe Hello.obj -llibswiftCore -llibswiftSwiftOnoneSupport -Wl,<some link options>
> 
> Without #2080, I should use the *.ll-modifying-trick. It is perfect in this example.
> 
> But, we need the way to disable dllimport. The immediate mode did not work.

If it only affects immediate mode, this might be a problem with LLVM's MCJIT. I would recommend asking llvm-dev, cc-ing Lang Hames (lhames at apple.com), to see what the right thing to do to reference DLL exports from JIT code is.

-Joe

>   swift Hello.swift
>   LLVM ERROR: Program used external function '__imp_globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_func3' which could not be resolved!
> 
>   swift -O Hello.swift
>   LLVM ERROR: Program used external function '__imp__swift_getExistentialTypeMetadata' which could not be resolved!
> 
> It seems swift.exe call directly the function in the DLL without import library.
> 
> The feature also needed when we link to static library.
> 
> I don't know about the SIL, IR, so it is thankful someone tell me how to approach this problem.



> 
> 2016-05-07 5:01 GMT+09:00 Saleem Abdulrasool <compnerd at compnerd.org>:
> On Thu, May 5, 2016 at 5:26 PM, Joe Groff via swift-dev <swift-dev at swift.org> wrote:
> 
> > 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.
> 
> https://github.com/apple/swift/pull/2080 is a first cut attempt to do this.
>  
> 
> -Joe
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> 
> 
> -- 
> Saleem Abdulrasool
> compnerd (at) compnerd (dot) org
>