Plugins and D programs

[Martin Nowak]

On 03/13/2014 02:22 PM, Steve Teale wrote:
>
> main : ifd.d main.d
>      dmd -c ifd.d
>      dmd -c main.d
>      dmd main.o ifd.o -L-ldl -defaultlib=libphobos2.so -L-rpath=.
>
> plugin : plugin.d
>      dmd -c -shared -fPIC plugin.d
>      dmd plugin.o -shared -defaultlib=libphobos2.so -map
>
> clean :
>      rm *.o
>      rm main
>      rm plugin.so

One problem here is that main and the plugin share the definitions in 
ifd.d. Therefor you need to move the interface into it's own shared 
library and link both (main and any plugin) against the interface 
definition.

main : main.d ifd
      dmd -c main.d
      dmd main.o -L-ldl -defaultlib=libphobos2.so -L-rpath=. -L./ifd.so

plugin : plugin.d ifd
      dmd -c -shared -fPIC plugin.d
      dmd plugin.o -shared -defaultlib=libphobos2.so -L./ifd.so

ifd : ifd.d
      dmd -c -shared -fPIC ifd.d
      dmd ifd.o -shared -defaultlib=libphobos2.so

clean :
      rm *.o
      rm main ifd.so plugin.so

Note that it was possible to load plugin.so even though it has undefined 
symbols because we link with -L--export-symbols (for backtrace symbols). 
This linker flag causes the main executable to export it's symbols, so 
the plugin will resolve it's undefined symbols by using the ones from 
main. I'm still investigating why it crashes when using --export-dynamic 
though.