Re: win32 show-stoppers

[David Chisnall]

On 2 Jan 2015, at 03:39, Hovik Melikyan <address@hidden> wrote:
> 
> The attached patch completes the MinGW 32-bit port, plus it has some
> bits for MinGW 64-bit and also some trivial fixes for OS X 32-bit.

Thanks.  Is there any chance you can put this on github (create a branch and 
rebase squashing everything into a single commit) for easier review?

> 
> The weak linking problem is solved by walking through the loaded DLLs
> at run time. This is done only once upon the first call to
> __cxa_begin_catch.

It probably belongs in the objc load function, so we avoid a conditional on 
every catch.

> The story with MinGW64 is this: I have the impression clang is not
> quite ready yet. Unfortunately my knowledge of EH personality stuff is
> virtually zero, but as I understand it, the fact that clang emits
> __gcc_personality_v0 (i.e. Dwarf2 model) on MinGW64 is just not right.
> The SEH patent has expired and there is mentioning on the internet
> that some work on llvm/clang is underway, but in any case it doesn't
> work out of the box. Unless of course I'm missing something.

That's an easy change to make, but I'm not overly familiar with the MinGW 
unwinder, but I think we need to write a _seh variant of the personality 
function.  There's already an abstraction layer to paper over the differences 
between the Itanium and ARM EH ABIs, so this ought to be extensible to add SEH 
support.

I don't recall if the support in LLVM is actually for SEH or for the Win64 
exceptions.  Can you see if exceptions work correctly with C++ and clang on 
Windows?  If so, then it should be easy to add the missing Objective-C parts.

> (In the meantime I have also ported GNUstep Base and packaged it
> together with libobjc2 into something I call Subjective:
> https://github.com/crontab/Subjective The idea is that you can have
> non-GUI runtime for Objective-C on WIndows and that you don't need the
> (overengineered) GNUstep build system for building it; simple
> makefiles are provided instead.)

I find the GNUstep build system incredibly annoying and would love to see it 
use CMake so that I can generate XCode projects when I'm on a Mac or Ninja 
files for *NIX.

David

-- Send from my Jacquard Loom