llvm dev - Oct 2009 - [LLVMdev] Problems linking shared library with __declspec(dllexport)

Hi all,

I am trying to use llvm-gcc to link shared libraries on windows/mingw32.
When I try to link libraries that contain functions declared with
  __declspec(dllexport) someFunction();

I get the link error:

  Cannot export _someFunction: symbol not found

Removing the declspec directive solves the problem, but this is not a 
very feasible solution for me.
Using 'regular' gcc does not have this problem.

Should I consider this a bug?

Thanks,

Ronald

> I am trying to use llvm-gcc to link shared libraries on windows/mingw32.
> When I try to link libraries that contain functions declared with
>  __declspec(dllexport) someFunction();
>
> I get the link error:
>
>  Cannot export _someFunction: symbol not found
dllexport declspec should be put on the function definition, in this
example there is nothing to export - dllexport without function body
is meaningless.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

Anton Korobeynikov <anton at korobeynikov.info> writes:
>> I am trying to use llvm-gcc to link shared libraries on
windows/mingw32.
>> When I try to link libraries that contain functions declared with
>>  __declspec(dllexport) someFunction();
>>
>> I get the link error:
>>
>>  Cannot export _someFunction: symbol not found
> dllexport declspec should be put on the function definition, in this
> example there is nothing to export - dllexport without function body
> is meaningless.
This is not correct.

The compiler remembers the dllexport declspec and when it finds the
definition, it applies it.

It works on MSVC++ and MinGW's gcc.

-- 
Óscar

> > I am trying to use llvm-gcc to link shared libraries on
windows/mingw32.
> > When I try to link libraries that contain functions declared with
> >  __declspec(dllexport) someFunction();
> >
> > I get the link error:
> >
> >  Cannot export _someFunction: symbol not found
> dllexport declspec should be put on the function definition, in this
> example there is nothing to export - dllexport without function body
> is meaningless.
Ok, you're right.
The declaration is actually there in the function definition.
Sorry to provide a broken example.
Here is a more acurate one:

--- function.c
  __declspec(dllexport) someFunction()
  {
      printf("Hi\n");
  }
---

Compiling this gives:

  $ llvm-gcc -shared -o libfunction.dll function.c
  Cannot export _someFunction: symbol not found
  collect2: ld returned 1 exit status

Thanks,

Ronald