GDC can't link LuaD if separate compilation used (bug?)

[Iain Buclaw via D.gnu]

On 27 April 2014 05:30, ketmar via D.gnu <d.gnu at puremagic.com> wrote:
> if i take LuaD[1] and then try to compile it as a set of separate .o files,
> gdc refuses to link any LuaD sample with message:
> hello.o:(.data._D30TypeInfo_S4luad4base9LuaObject6__initZ[_D30TypeInfo_S4luad4base9LuaObject6__initZ]+0x1c):
> undefined reference to
> `_D4luad4base9LuaObject11__xopEqualsFKxS4luad4base9LuaObjectKxS4luad4base9LuaObjectZb'
>
> but if i'll do whole thing at once (i.e. passing all .d files in command
> line w/o separate linking phase), everything working ok.
>
> here is two scripts that should be put in root LuaD directory to reproduce
> the issue:
>
> linking failed: http://pastebin.com/Vh27BFBP
> everything ok: http://pastebin.com/Gzn7B1Du
>
> i'm using gdc 3209d01d42b6e… and gcc 4.9 on GNU/Linux, x86. here is gcc -v
> output:
>
> Configured with: ../gcc-4.9.0/configure --prefix=/usr --libdir=/usr/lib
> --mandir=/usr/man --infodir=/usr/info --disable-nls --enable-shared
> --enable-bootstrap --enable-languages=c,c++,lto,objc,d
> --enable-threads=posix --enable-checking=release --enable-objc-gc
> --with-system-zlib --without-python --disable-libunwind-exceptions
> --enable-__cxa_atexit --enable-libssp --with-gnu-ld
> --with-arch-directory=i386 --disable-gtktest --with-arch=i486
> --target=i486-slackware-linux --build=i486-slackware-linux
> --host=i486-slackware-linux
>
> 1. https://github.com/JakobOvrum/LuaD

The opEquals implementation of LuaObject is a template.  So it's
symbol won't be instantiated when compiling luad.base on it's own.

https://github.com/JakobOvrum/LuaD/blob/master/luad/base.d#L184

It's also likely that the compiler's rules for whether or not an
instantiated template needs to be emitted, decides to instead discard
opEquals when compiling the other modules separately.

Try compiling with -femit-templates to force the behaviour of D prior
to 2.064, see this bug report:

https://issues.dlang.org/show_bug.cgi?id=11114


Regards
Iain