why to mention not to mangle the name when calling a c++ function from other c++ dll

Question

This is my exported function in dll1

        extern"C" __declspec(dllexport) int FUN1(char* p){
        return p[0];
        }

    I am calling this FUN1 from other project.Below is the code

        #include
        #include
        using namespace std;
        typedef int (*MYFUN1)(char*);

        int main()

            {

                HMODULE hMod = LoadLibrary ("C:\\Users\\admin\\Documents\\Visual Studio 2010\\Projects\\CalledFun\\Debug\\CalledFun.exe");
                if(hMod != NULL)
                {
            MYFUN1 pCtor = (MYFUN1) GetProcAddress (hMod, "FUN1");
            int a = pCtor("calling a value") ;
            cout<<a;
                }
            }

If I remove the extern "C" from dll1 then that function address is returning as NULL when calling GetProcAddress in dll2. Since both are written in c++ I thought name mangling will not effect this.I thought if we use c and c++ libraries combinely then only we need to mention extern "C" ,Can anyone help me to get out of this confusion

Thanks in advance

Call me crazy, but calling `LoadLibrary` with an `.exe` into it seems...incorrect. — Colin Basnett, Jul 23 '15 at 03:03
Please see this: http://stackoverflow.com/questions/31282683/dll-call-with-stdcall-getprocaddress-in-vs2013/31283377#31283377 — PaulMcKenzie, Jul 23 '15 at 03:08
And please note -- it doesn't matter if it is a DLL or EXE. The rules of the game are the same. — PaulMcKenzie, Jul 23 '15 at 03:16
@cmbasnett You can export functions from an EXE. It's rare, but it can be done since a DLL and EXE are both considered executable modules. — PaulMcKenzie, Jul 23 '15 at 03:19
You can in principle use mangled names, but then `GetProcAddress` would have to use mangled names too. Which is a little bit inconvenient. — n. m. could be an AI, Jul 23 '15 at 03:50

score 1 · Answer 1 · answered Jul 23 '15 at 03:56

1

You need to disable name mangling because you are using Windows API like LoadLibrary to which you provide function name. Windows API an LoadLibrary in particular know nothing about your compiler name mangling, so you need to turn it off.

answered Jul 23 '15 at 03:56

Roman Kolesnikov

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why to mention not to mangle the name when calling a c++ function from other c++ dll

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