Shared library for class which uses extern struct

ROOT
1

Dear ROOTers,
My various attemps failed to make a shared library for a class which uses external C structure.
A short example of code figuring out the problem is in attachment.
MyClass.tar.gz (2.06 KB)

2

Hello,

I don’t know if this is a legal source code for C/C++.
First, you have struct defined with in a namespace and without extern “C”. Then later, you define the same struct name in extern “C”. I think those are distingushed as different ones by C++ compiler. You have to be consistent. For example,

extern “C” {
struct yourstruct { … }
}
namespace yournamespace {
extern “C” struct yourstruct;
}

Thank you
Masa Goto

3

Hello,

A variant with the commented description of a structure produces even an error
in MyClassDict.cxx compilation. I just use these structure as prescribed method for
linkage with a fortran common.
I’ve managed to compile, link without ROOT and execute modules with
both variants of the structure description.
Is it possible to emdeb something like this in ROOT?
Valery.

4

Hello Valery,

Please simplify your code. I see complicated dependency between C and C++ namespace. Commeting out struct definition is not sufficient. I could compile it after separating C and C++ portion.

Thank you
Masa Goto

5

Hello Masa,

Even if i get rid of the namespace i don’t see the structure.

                                  Thank you for help, Valery.
6

Hi,

Note that the pragma defined_in requires a full pathname.
So you need to add an explicity request to generate the dictionary for your struct.

Cheers,
Philippe.