dynamic library building and loading

[Jacob Carlborg]

On 2012-09-30 08:41, Rob T wrote:

> There are plenty of cases where you have to use a dynamically loaded lib
> even if you know before hand what will be loaded. I think you understand
> this if I read your posts correctly.
>
> In my case I have a pre-existing C++ app that is designed to load user
> defined C++ plugins. I wanted to interface D to one of my own C++
> plugins, but I apparently cannot do it reliably because of
> initialization issues with the GC and possibly some other obscure items.

But now we're back at plugins. I think this part of the discussion is 
starting to run in circles and become quite pointless. I think most of 
us know that we need to support all types of libraries. Static and 
dynamic, both for link time and runtime.

> If I can figure out what needs to be done to resolve the problem in
> enough detail, then maybe I can hack the runtime source and roll out a
> solution.

You can have a look at the work done by Martin Nowak:

https://github.com/dawgfoto/druntime/commits/SharedRuntime

He has a couple of other useful branches as well, for example:

https://github.com/dawgfoto/druntime/commits/dmain2Refactoring

On Mac OS X there's also the problem with TLS. There is no native 
support for TLS in Mac OS X prior to Lion (10.7). DMD has rolled its own 
implementation that needs to be adapted to support dynamic libraries.

> The GC always seems to pop up as a source of problems. For long term
> solution, the GC should be made 100% optional (in practice as opposed to
> in theory), the standard library ought to be made to work with or
> wothout a GC (or simply without), and the GC itself should be easily
> replaceable with alternate versions. I think this idea has already been
> discussed elsewhere, and is on the TODO list (I hope!).

You can replace the GC at link time. Here's an example of a stubbed 
implemented of the GC:

http://dsource.org/projects/tango/browser/trunk/tango/core/rt/gc/stub

This is for Tango but the druntime is based on the Tango runtime so I 
would guess most of this would be the same.

-- 
/Jacob Carlborg