llvm dev - Apr 2012 - [LLVMdev] Building LLVM as a shared library using Visual C++ 2010?

Óscar Fuentes <ofv at wanadoo.es> writes:
> Michael Spencer <bigcheesegs at gmail.com> writes:
> > The problem is that MSVC++ requires sprinkling
> > __declspec(dllexport/dllimport) all over the code, and we really
don't
> > want to deal with maintaining that, as most developers have little to
> > no experience with Windows DLLs.
>
> BTW, you don't put __declspec(dllexport) / __declspec(dllimport) on the
> code, but macros that alternatively expand to those declspecs depending
> on if the library is being compiled or referenced.
I have just realised that I directly replied to Michael rather than the
mailing list (!!), but it was to say the same as Óscar with regards to the
use of a macro. In fact, I am thinking of taking this approach for the
classes that I need in my project. Still, it will mean 'hacking' the
code
myself, and I really wish I didn't have to go that route, but... what other
choice do I have if I want to use MSVC?...
> Yeah, I tried that too. AFAIK the 2^16 symbol limitation on the VS
> linker applies to .def files in general, not just when exporting by
> ordinal. One problem I found was to differentiate the relevant stuff
> from the junk while deciding what to put on the .def file. I find it
> hard to believe that any LLVM library exports 65000 symbols. Maybe
> fine-tuning the symbol filtering the .def files could be used regardless
> the 2^16 limit, altough generating those .def files would never be as
> reliable as putting the declarations on the source code, IMO.
FWIW, using MinGW, I end up with a DLL with 13,320 symbols. Still, I agree
with Óscar, this wouldn't be as reliable as using a macro (not to mention
that maintenance could be a bit of a nightmare).

Alan

On Sat, Apr 7, 2012 at 11:58 PM, Alan Garny <agarny at hellix.com> wrote:
> Óscar Fuentes <ofv at wanadoo.es> writes:
> > Michael Spencer <bigcheesegs at gmail.com> writes:
> > > The problem is that MSVC++ requires sprinkling
> > > __declspec(dllexport/dllimport) all over the code, and we really
don't
> > > want to deal with maintaining that, as most developers have
little to
> > > no experience with Windows DLLs.
> >
> > BTW, you don't put __declspec(dllexport) / __declspec(dllimport)
on the
> > code, but macros that alternatively expand to those declspecs
depending
> > on if the library is being compiled or referenced.
>
> I have just realised that I directly replied to Michael rather than the
> mailing list (!!), but it was to say the same as Óscar with regards to the
> use of a macro. In fact, I am thinking of taking this approach for the
> classes that I need in my project. Still, it will mean 'hacking'
the code
> myself, and I really wish I didn't have to go that route, but... what
other
> choice do I have if I want to use MSVC?...
>
Until this is resolved, why not statically link?

>
> > Yeah, I tried that too. AFAIK the 2^16 symbol limitation on the VS
> > linker applies to .def files in general, not just when exporting by
> > ordinal. One problem I found was to differentiate the relevant stuff
> > from the junk while deciding what to put on the .def file. I find it
> > hard to believe that any LLVM library exports 65000 symbols. Maybe
> > fine-tuning the symbol filtering the .def files could be used
regardless
> > the 2^16 limit, altough generating those .def files would never be as
> > reliable as putting the declarations on the source code, IMO.
>
> FWIW, using MinGW, I end up with a DLL with 13,320 symbols. Still, I agree
> with Óscar, this wouldn't be as reliable as using a macro (not to
mention
> that maintenance could be a bit of a nightmare).
>
> Alan
>
>
> _______________________________________________
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> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>


-- 

Thanks,

Justin Holewinski
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> From: Justin Holewinski [mailto:justin.holewinski at gmail.com]
> On Sat, Apr 7, 2012 at 11:58 PM, Alan Garny <agarny at hellix.com>
wrote:
> 
>> I have just realised that I directly replied to Michael rather than the
>> mailing list (!!), but it was to say the same as Óscar with regards to
the
>> use of a macro. In fact, I am thinking of taking this approach for the
>> classes that I need in my project. Still, it will mean
'hacking' the code
>> myself, and I really wish I didn't have to go that route, but...
what
other
>> choice do I have if I want to use MSVC?...
> 
> Until this is resolved, why not statically link?
Because everything in my (Qt) application is a plugin, so LLVM is a plugin
which can be used by other plugins that need LLVM's functionalities. This
all works fine with MinGW on Windows, and gcc on Linux and Mac OS X, but now
I need to get things to work with MSVC on Windows and I am kind of stuck. 

Alan