linker error

koso · Post by **koso** » Tue Jan 18, 2011 5:25 pm

Hi

i am trying to make my own small library, to put together graphics irrklsng and stuff. but when i am trying to compile i get this

Code: Select all

1>TGlobals.obj : error LNK2005: "void __cdecl rotateNode(class irr::scene::ISceneNode *,class irr::core::vector3d<float>)" (?rotateNode@@YAXPAVISceneNode@scene@irr@@V?$vector3d@M@core@3@@Z) already defined in techEngine.obj
1>TGlobals.obj : error LNK2005: "void __cdecl translateNode(class irr::scene::ISceneNode *,class irr::core::vector3d<float>)" (?translateNode@@YAXPAVISceneNode@scene@irr@@V?$vector3d@M@core@3@@Z) already defined in techEngine.obj
1>TRender.obj : error LNK2005: "void __cdecl rotateNode(class irr::scene::ISceneNode *,class irr::core::vector3d<float>)" (?rotateNode@@YAXPAVISceneNode@scene@irr@@V?$vector3d@M@core@3@@Z) already defined in techEngine.obj
1>TRender.obj : error LNK2005: "void __cdecl translateNode(class irr::scene::ISceneNode *,class irr::core::vector3d<float>)" (?translateNode@@YAXPAVISceneNode@scene@irr@@V?$vector3d@M@core@3@@Z) already defined in techEngine.obj

can someone explain me what is going on? i want to understand it for future.

thx

Radikalizm · Post by **Radikalizm** » Tue Jan 18, 2011 6:20 pm

EDIT: Nevermind ^^

Alpha Omega · Post by **Alpha Omega** » Tue Jan 18, 2011 6:52 pm

It say already defined

(?translateNode@@YAXPAVISceneNode@scene@irr@@V?$vector3d@M@core@3@@Z) already defined in techEngine.obj

Are you perhaps trying to compile and using?

#include <file.cpp> because your not supposed to do that.

Iyad · Post by **Iyad** » Thu Jan 20, 2011 12:31 am

Maybe its occuring due to circular dependency, be sure that your files does not include themselfs more than once, use include guards or rework on your code. Sometimes, if 2 classes or more are interdependant, you can try to use a forward declaration, then redefine your declaration in another file.

Radikalizm · Post by **Radikalizm** » Thu Jan 20, 2011 12:41 am

Iyad wrote:Maybe its occuring due to circular dependency, be sure that your files does not include themselfs more than once, use include guards or rework on your code

This could very well be the problem
You should make it a standard practice to immediately add this to a newly created header file:

Code: Select all

#ifndef    __FILE_NAME_H__
#define    __FILE_NAME_H__

// You can name the define anything you want, as long as it remains unique throughout your program


/*
CODE GOES HERE
*/

#endif    // __FILE_NAME_H__

Anthony · Post by **Anthony** » Thu Jan 20, 2011 1:06 am

second that of Radkalizm

But it only counts for header files.

To keep them unique, just use the filename of the header, i.e.:

Code: Select all

// header file: header.h
#ifndef _HEADER_H_
etc.

as filenames are unique too (unless you name them into different directories the same, wich you shouldn't

)