msft c unresolved external tying to use dll function in win32 console app

Asked Oct 09 '18 at 05:44

Active Oct 09 '18 at 05:44

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I have a very simple c++ dll that adds two numbers. The source file looks like:

extern "C" {
__declspec(dllexport) double __stdcall myadder(double a,double a)
{
    return (a+b);
}
}

with a def file:

LIBRARY myadder
EXPORTS
    _myadder@16

The code of the exe is:

#include "stdio.h"

__ declspec(dllimport) double myadder(double a, double b);


int main()
{
double r;

r=myadder(5,6);

printf("myadder = %f \n",r);


return 0;
}

and I tell it to use myadder.lib qualified with the path to it. but I get the error:

1>helloworld.obj : error LNK2019: unresolved external symbol __imp__myadder referenced in function _main

1>C:\lotus\optfunc\helloworld\Debug\helloworld.exe : fatal error LNK1120: 1 unresolved externals

and if I get rid of the __declspec(dllimport) I instead get:

1>helloworld.obj : error LNK2019: unresolved external symbol _myadder referenced in function _main

What am I doing wrong?

asked Oct 09 '18 at 05:44

RichT

You don't seem to be linking the EXE with the import library for the DLL. – Igor Tandetnik Oct 09 '18 at 14:36
@igor tandetnik I tell it to use myadder.lib – RichT Oct 09 '18 at 22:16
Mismatched calling convention. You make it `__stdcall` in the DLL, but the default (usually `__cdecl`) in the EXE. – Igor Tandetnik Oct 10 '18 at 00:25
@IgorTandetnik Bingo! Thanks so much! How do I mark that as an answer? – RichT Oct 10 '18 at 01:11

msft c unresolved external tying to use dll function in win32 console app

0 Answers0