[Solved] Can't link to Windows library

RickH

Hello all. After much reading and hacking, I have a program that compiles, but doesn't link. The program is the client half of a tcp connection. It complains that it can't find a library:

readevalprintloopthread.obj:-1: error: LNK2019: unresolved external symbol __imp__freeaddrinfo@4 referenced in function "public: void __thiscall ReadEvalPrintLoopThread::ConnectToServer(void)" (?ConnectToServer@ReadEvalPrintLoopThread@@QAEXXZ)

I have a pure Microsoft solution somebody gave me, and I can make that solution stop building by hiding a certain library, so I think I've found the library it can't find. (WS2_32.lib) I checked my lib path based on this suggestion on the net:

http://stackoverflow.com/questions/718447/adding-external-library-into-qt-creator-project

but the lib path seems to be there.

Doesn't anybody know why I can't find this library?

(I'm sure somebody will ask me, so I'll say now: I'm using Microsoft socket facilities and not Qt socket facilities because the objective is to show somebody that I understand Unix/Windows tcp. I wrote it in Qt Creator so I could use the other facilities.)

         Regards, Rick

loladiro

Are you using qmake? If yes, could you show us the LIBS statements?

gedd

If your solution is pure Ms, try to just add WS2_32.lib to the LIBS statement

@win32:LIBS += -lWS2_32@

or

@win32:LIBS += WS2_32.lib@

RickH

Hi. I made a similarly named post over in General, but I've realized this is a better place for it, and I've figured out a simpler way to ask my question.

Can anybody compile and link this? :

@
#include <QtCore/QCoreApplication>
#include <ws2tcpip.h>
int main(int argc, char *argv[]) {
QCoreApplication a(argc, argv);
struct addrinfo * servinfo = NULL;
freeaddrinfo(servinfo);
return a.exec();
}
@

When I try, I can't link it. :

LNK2019: unresolved external symbol __imp__freeaddrinfo@4 referenced in function _main

          Regards, 

          Rick

EDIT: please use @-tags for code highlight, Gerolf

RickH

Hi. I am using Qt Creator. I suspect that if I could find this LIBS of which you speak, my problems would be over.

I'm willing to say "Qt Creator doesn't handle this correctly. I should go one level lower, closer to the metal, and use qmake." Is that what I should say?

I figured out a way to ask my question more simply, and so I did, over in the Tools forum. Same title.

         Regards, Rick

Eddy

I merged this 2 threads because this is about the same problem.

Could you use @tags for your code please? Or use button with <> on it on top of editor. It makes it more readible for others.

loladiro

The LIBS directive has to go into your .pro file.

gedd

bq. Hi. I made a similarly named post over in General, but I’ve realized this is a better place for it, and I’ve figured out a simpler way to ask my question.
Can anybody compile and link this? :
....
When I try, I can’t link it. :
LNK2019: unresolved external symbol __imp__freeaddrinfo@4 referenced in function _main

I have the same error without change anything but when i add @win32:LIBS += -lWS2_32@ to the .pro file it works fine !!!!

RickH

I will use @tags the next time I include code. And I guess two threads for the same topic is considered undesireable. I won't do that again.

Adding the line to ...pro worked. I wasn't aware that I had access to qmake through that file.

This environment is very pleasant. There seem to be fewer unnecessary obstacles than in other environments.

Thanks for your help.

       Rick

Eddy

Glad to hear you like Qt!

Please could you edit your title and add [Solved] in front of it?