Problems linking shared library with __declspec(dllexport)

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#1

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

#2

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.

#3

Anton Korobeynikov <anton@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.

#4

> 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");
  }

#5

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

Right, this is a bug introduced recently - we need to emit linker
directive with unmangled, but decorated name...