Win64: link fails with lots of object files

[rainers]

Building druntime with a Visual D project puts all modules on the commandline (through a response file), but linking the unittest executable or creating the library fails with

The command line is too long.
Error: C:/s/d/ldc/build-ldc2-x64/bin/Debug/x86.bat failed with status: 1

This happens because the list of arguments is longer than the limit for batch files (8192 characters). LDC should switch to a response file in this case, too.

[kinke]

Thanks for the report. I've noted that you seem to be cross-compiling to 32-bit code; please note that this is not officially supported yet. There are probably some MSVC-specific branches which are guarded by Win64 checks instead of checking for MSVC; probably not just in LDC, but in druntime and Phobos too. And Win32 used to be supported via MinGW, so there may be some MinGW-specific branches guarded by Win32 checks. ;)

Edit: And Kai mentioned that exception handling isn't supported either for x86 MSVC, also leading to linking errors.

[rainers]

I've noted that you seem to be cross-compiling to 32-bit code; please note that this is not officially supported yet.

I'm actually trying to get LDC working for Win32, too. I succeeded to some extent with LLVM 3.7, until I noticed that clang also failed to access caught objects correctly. That's why I switched to LLVM 3.8 and now have C++ compatible exception handling, but it still fails in complex situations.

[dnadlinger]

Marking as closed as per your comment in @kinke's #1165.

[kinke]

I'm actually trying to get LDC working for Win32, too.

Oh, cool - all the best! 👍

I succeeded to some extent with LLVM 3.7, until I noticed that clang also failed to access caught objects correctly. That's why I switched to LLVM 3.8 and now have C++ compatible exception handling, but it still fails in complex situations.

Are you already using LLVM's new EH instructions?

[rainers]

Are you already using LLVM's new EH instructions?

Yes. I started with the beginCatch/endCatch intrinsics of LLVM 3.7, but had to switch to the new instructions for 3.8.

[kinke]

Interesting. I suggest you open a work-in-progress PR soon, so that others see that there's movement on that front (and may chime in) - Manu was here ~2 weeks ago and wanted to hack on LLVM too, so he may be working on the same stuff. And Kai is interested in getting a working MSVC Win32 build too once he's finished his book...

[rainers]

I suggest you open a work-in-progress PR soon, so that others see that there's movement on that front (and may chime in)

Good idea. I'll have to cleanup and comment the code a bit and make sure it still compiles with earlier versions of LLVM, though. I'm not sure I'll get to this the next couple of days.

[rainers]

I suggest you open a work-in-progress PR soon,

PRs now available as #1168 and ldc-developers/druntime#35