[Issue 15579] extern(C++) interfaces/multiple-inheritence

Jan 18, 2016

https://issues.dlang.org/show_bug.cgi?id=15579 Manu <turkeyman@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |C++ --

https://issues.dlang.org/show_bug.cgi?id=15579 deadalnix <deadalnix@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |deadalnix@gmail.com --- Comment #1 from deadalnix <deadalnix@gmail.com> --- https://mentorembedded.github.io/cxx-abi/abi.html#vtable --

https://issues.dlang.org/show_bug.cgi?id=15579 Walter Bright <bugzilla@digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bugzilla@digitalmars.com --- Comment #2 from Walter Bright <bugzilla@digitalmars.com> --- Compilable D version of the code: extern (C++) { class Base { ~this() {} size_t x = 4; } interface Interface { int Method(); } class Derived : Base, Interface { size_t y = 5; int Method() { return 3; } } } The layout for Win64 Base is: 4Base6__initZ: void* &vtbl size_t x; The layout for Win64 Derived is: 7Derived6__initZ: void* &vtbl size_t x; size_t y; void* &vtbl These can be figured out by running obj2asm on the object file and looking at it. --

https://issues.dlang.org/show_bug.cgi?id=15579 --- Comment #5 from github-bugzilla@puremagic.com --- Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/316f2e900dc16ce1351a305c58bad287b2855ad5 fix Issue 15579 - extern(C++) interfaces/multiple-inheritance https://github.com/D-Programming-Language/dmd/commit/c6ac10aed0f7dc76112e576204e3a1e8ea307dbd Merge pull request #5361 from WalterBright/fix15579 fix Issue 15579 - extern(C++) interfaces/multiple-inheritance --

January 23, 2016

[Issue 15579] extern(C++) interfaces/multiple-inheritance

Posted by Manu

Permalink

Manu

Permalink

https://issues.dlang.org/show_bug.cgi?id=15579

--- Comment #7 from Manu <turkeyman@gmail.com> ---
I was just doing some work with the latest nightly (should have this patch in
it).
I got a compile error that's new since the last nightly I was using:

3>Building bin\Debug_x64\dplug.dll...
3>libdep.lib(component_344_d5.obj) : fatal error LNK1179: invalid or corrupt
file: duplicate COMDAT '??1Component@ep@@QEAA@XZ'

The project structure is:
  cpplib.lib --+
  dlib.lib ----|
               |
           dplug.dll

So, cpplib has the stuff I'm extern-ing to, dlib is a binding to cpplib with
some adaptation support code, and dplug is a dll which links both libs.
dlib is mostly extern(C++)'s, and a bunch of extra (mostly extern(D)) code for
adaptation.
I presume that symbol exists in cpplib, but the error suggests that D is also
emitting the same symbol somewhere?


Possibly uninteresting, but I have a lot of code like this:

extern(C++) class CppClass
{
  void cppMethod(ref const(CustomString) &s);
  void cppMethod2();

extern(D):
  void dAdapterMethod(const(char)[] s) { auto temp = CustomString(s.ptr,
s.length); cppMethod(temp); }
}

This is a simple example, but there's a lot of this going on... so the
extern(C++) classes are kitted out with a bunch of extra functions on the D
side.
I only say this, because I wonder if the fact that I'm not strictly binding,
but also extending may lead to symbols being emitted...

--

Forums