I'm following the preliminary example "Dynamically Loading a D DLL From a C Program" here: http://dlang.org/dll-linux.html#dso9

Firstly, my output is different:

+main()
libdll.so is loaded
dll() function is found
dll()
unloading libdll.so
-main()

If looks like static this and ~this are not being called.

Secondly, when I replace printf with writeln, I get a seg fault. Trying to do just about anything beyond adding numbers and returning the result causes a similar crash.

I'm wondering whether D runtime is being initialized correctly. Can anyone suggest what I would do to ensure this? A more finalized example would be useful also.

DMD64 D Compiler v2.066.0
Ubuntu 10.04 64bit

Many thanks,
John

Apologies. That should be Ubuntu 14.04.

On Friday, 24 October 2014 at 20:59:20 UTC, John McFarlane wrote:
> I'm following the preliminary example "Dynamically Loading a D DLL From a C Program" here: http://dlang.org/dll-linux.html#dso9
>
> Firstly, my output is different:
>
> +main()
> libdll.so is loaded
> dll() function is found
> dll()
> unloading libdll.so
> -main()
>
> If looks like static this and ~this are not being called.
>
> Secondly, when I replace printf with writeln, I get a seg fault. Trying to do just about anything beyond adding numbers and returning the result causes a similar crash.
>
> I'm wondering whether D runtime is being initialized correctly. Can anyone suggest what I would do to ensure this? A more finalized example would be useful also.
>
> DMD64 D Compiler v2.066.0
> Ubuntu 10.04 64bit
>
> Many thanks,
> John

I can't answer the first question, but for the second, I've given an example here:

http://forum.dlang.org/post/zfdvrwvgavykauczbreq@forum.dlang.org

I've done that many, many times and do not see any problems related to the runtime.

On Friday, 24 October 2014 at 20:59:20 UTC, John McFarlane wrote:
> I'm following the preliminary example "Dynamically Loading a D DLL From a C Program" here: http://dlang.org/dll-linux.html#dso9
>
> Firstly, my output is different:
>
> +main()
> libdll.so is loaded
> dll() function is found
> dll()
> unloading libdll.so
> -main()
>
> If looks like static this and ~this are not being called.
>
> Secondly, when I replace printf with writeln, I get a seg fault. Trying to do just about anything beyond adding numbers and returning the result causes a similar crash.
>
> I'm wondering whether D runtime is being initialized correctly. Can anyone suggest what I would do to ensure this? A more finalized example would be useful also.
>
> DMD64 D Compiler v2.066.0
> Ubuntu 10.04 64bit
>
> Many thanks,
> John

On Friday, 24 October 2014 at 22:33:09 UTC, bachmeier wrote:
> I can't answer the first question, but for the second, I've given an example here:
>
> http://forum.dlang.org/post/zfdvrwvgavykauczbreq@forum.dlang.org
>
> I've done that many, many times and do not see any problems related to the runtime.
>
> On Friday, 24 October 2014 at 20:59:20 UTC, John McFarlane wrote:
>> I'm following the preliminary example "Dynamically Loading a D DLL From a C Program" here: http://dlang.org/dll-linux.html#dso9
>>
>> Firstly, my output is different:
>>
>> +main()
>> libdll.so is loaded
>> dll() function is found
>> dll()
>> unloading libdll.so
>> -main()
>>
>> If looks like static this and ~this are not being called.
>>
>> Secondly, when I replace printf with writeln, I get a seg fault. Trying to do just about anything beyond adding numbers and returning the result causes a similar crash.
>>
>> I'm wondering whether D runtime is being initialized correctly. Can anyone suggest what I would do to ensure this? A more finalized example would be useful also.
>>
>> DMD64 D Compiler v2.066.0
>> Ubuntu 10.04 64bit
>>
>> Many thanks,
>> John

Thanks. That gets me a lot futher.

// MGW 05.01.14
// We model in D object C ++ QByteArray from Qt.
//--------------------------------------------
// Windows: dmd st1.d
//   Linux: dmd st1.d -L-ldl

import core.runtime;     // Load DLL for Win
import std.stdio;        // writeln

version(linux) {
    import core.sys.posix.dlfcn;  // declare dlopen() и dlsym()

    // On Linux these functions are not defined in core.runtime, here and it was necessary to add.
    extern (C) void* rt_loadLibrary(const char* name) { return dlopen(name, RTLD_GLOBAL || RTLD_LAZY);  }
    void* GetProcAddress(void* hLib, string nameFun) {  return dlsym(hLib, nameFun.ptr);    }
}
version(Windows) {
	import std.c.windows.windows;  // GetProcAddress для Windows
}
//it is important!!!
//At definition constructs and functions of members the attribute "extern (C)" is obligatory!
alias extern (C) void function(void*, char*)       t_QByteArray_QByteArray;  t_QByteArray_QByteArray  QByteArray_QByteArray;
alias extern (C) void* function(void*, char, int)  t_QByteArray_fill;        t_QByteArray_fill        QByteArray_fill;

// Struct QByteArray from qbytearray.h in include directory.
// inline char *QByteArray::data() { detach(); return d->data; } где d есть Data*
struct Data {
        void* rref;
        int   alloc;
        int   size;
        char* data;      // Here actually behind what it is necessary for us, the index on a file of bytes
        char  array[1];
}

// == Experimental class DQByteArray ==
class DQByteArray {
    Data* QtObj;       // Object: &QtObj - its size of 4 bytes (32 digit version)
    // ------------------
    // class D, call class C++
    this(char* buf) {
        QByteArray_QByteArray(&QtObj, buf);
    }
    ~this() {
        // It is possible to find ~this and here it to register, but it is routine....
    }
    // inline char *QByteArray::data() { detach(); return d->data; } где d есть Data*
    char* data() {
        return (*QtObj).data;
    }
    // D: Data** ==> C++: QByteArray Here also it became clear, that such object With ++, looking at it from D
    void* fill(char ch, int resize=-1) {
        return QByteArray_fill(&QtObj, ch, resize);
    }
}

int main(string[] args) {

// Files with QByteArray C++
version(linux)   {    auto nameQtCore = "libQtCore.so";  }
version(Windows) {    auto nameQtCore = "QtCore4.dll";   }

    auto h = Runtime.loadLibrary(nameQtCore); // Load dll или so

    // It is QByteArray::QByteArray(char*);
    QByteArray_QByteArray = cast(t_QByteArray_QByteArray)GetProcAddress(h, "_ZN10QByteArrayC1EPKc");
    // QByteArray::fill(char*, int);
    QByteArray_fill = cast(t_QByteArray_fill)GetProcAddress(h, "_ZN10QByteArray4fillEci");

    // Create my class
    DQByteArray ba = new DQByteArray(cast(char*)"ABC".ptr);
    printf("\n ba.data() = %s", ba.data());

    // Test fill() from C++
    ba.fill('Z', 5);
    printf("\n ba.data() = %s", ba.data());

    return 0;
}