error LNK2019 unresolved external symbol - Class Library issue? - c++

I have one solution with 2 projects in it. (VS2013)
One project is a Direct3D with XAML project, the other is a Static class library.
I have set up project dependencies.
I am wondering if the unresolved external symbols could be anything to do with this.
Here are the errors i'm getting... and i'm finding it hard to understand their meaning
Error 1 error LNK2019: unresolved external symbol "public: __thiscall Game::Model::Input::Keyboard::Keyboard(void)" (??0Keyboard#Input#Model#Game##QAE#XZ) referenced in function "public: __cdecl Game::App::App(void)" (??0App#Game##Q$AAA#XZ) C:\Users\James\Documents\Visual Studio 2013\Projects\Games\Jimmy\Game\App.xaml.obj Game
Error 2 error LNK2019: unresolved external symbol "public: __thiscall Game::Model::Entities::Player::Player(void)" (??0Player#Entities#Model#Game##QAE#XZ) referenced in function "public: void __thiscall Game::PlayerRenderer::InstantiateDependantObjects(void)" (?InstantiateDependantObjects#PlayerRenderer#Game##QAEXXZ) C:\Users\James\Documents\Visual Studio 2013\Projects\Games\Jimmy\Game\PlayerRenderer.obj Game
Error 3 error LNK1120: 2 unresolved externals C:\Users\James\Documents\Visual Studio 2013\Projects\Games\Jimmy\Debug\Game\Game.exe 1 1 Game
This is one part of the code it is struggling with:
Model project
Model\Entities\Keyboard.h
#pragma once
namespace Game
{
namespace Model
{
namespace Input
{
class Keyboard
{
public:
Keyboard();
bool Up;
bool Down;
bool Left;
bool Right;
bool Space;
bool Escape;
};
}
}
}
Model\Entities\Keyboard.cpp
#include "pch.h"
#include "Entities\Keyboard.h"
using namespace Game::Model::Input;
Keyboard::Keyboard()
: Up( FALSE ),
Down( FALSE ),
Left( FALSE ),
Right( FALSE ),
Space( FALSE ),
Escape( FALSE )
{}
Game project
Game\App.xaml.h
#pragma once
...
#include "..\Model\Entities\Keyboard.h"
...
using namespace Game::Model::Input;
namespace Game
{
ref class App sealed
{
public:
...
private:
...
Keyboard* keyboard;
...
};
}
Game\App.xaml.cpp
App::App()
{
InitializeComponent();
keyboard = new Keyboard();
Suspending += ref new SuspendingEventHandler(this, &App::OnSuspending);
Resuming += ref new EventHandler<Object^>( this, &App::OnResuming );
}
...
Any ideas?

That dialog doesn't do what you hope it does, you are not actually linking your static library project. It used to in old VS versions before VS2010, now it only sets the build order.
Instead, use Project + Properties, Common Properties, References. Click the Add New Reference button and tick your library project.

Related

C++ DLL: unresolved external symbol

I seem to have some issues with creating new files for my project.
The issue is that in my sk_error.h file it seems to complain about unresolved external symbols (full error report below). When I place my OutOfRange class in my sk_interface.h file no one complains but when I put the class in the errors file it has issues with it.
If I was to comment out OutOfRange it works perfectly fine so I dont think that it is an issue with the DLL setup.
sk_error.h
#include <sk_platform.h>
#include <sk_interface.h>
namespace sky {
class SK_API OutOfRange : IError {
public:
OutOfRange() {
m_message = " Out Of Range";
m_value = (0 << 1);
}
std::string getMessage() override {
return m_message;
}
};
}
sk_platform.h
#if defined (SK_NONCLIENT_BUILD)
#ifndef SK_API
#define SK_API __declspec(dllexport)
#endif
#else
#ifndef SK_API
#define SK_API __declspec(dllimport)
#endif
#endif
sk_interface.h
#include <sk_platform.h>
#include <string>
namespace sky {
...
class SK_API IError {
public:
virtual std::string getMessage() = 0;
protected:
uint32_t m_value = 0;
std::string m_message = "Error not initialized";
};
}
The Client Project using the DLL
#include <sk_logmanager.h>
#include <sk_error.h>
#include <iostream>
int main() {
sky::g_LogManager.startup();
sky::OutOfRange err;
std::cout << err.getMessage() << "\n";
sky::g_LogManager.shutdown();
while (1) {}
}
Error Output
1>------ Build started: Project: SkyTest, Configuration: Debug Win32 ------
1>main.cpp
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sky::OutOfRange::OutOfRange(void)" (__imp_??0OutOfRange#sky##QAE#XZ) referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall sky::OutOfRange::getMessage(void)" (__imp_?getMessage#OutOfRange#sky##UAE?AV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##XZ) referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sky::OutOfRange::~OutOfRange(void)" (__imp_??1OutOfRange#sky##QAE#XZ) referenced in function _main
1>C:\Users\Matt\Documents\Game Development\DevEnv\SkyTest\Debug\SkyTest.exe : fatal error LNK1120: 3 unresolved externals
1>Done building project "SkyTest.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
Edit:
I am using Visual Studio 2017 (could be the source of the error). The Client Project is using the .lib file.
An unresolved external is always a link error. It even has it in its name: LNK2019.
It is telling you it cannot find the implementation for sky::OutOfRange::OutOfRange()
You have it in a header somewhere and you've called it, but you have not linked to the library that implements it.
We have no way of telling you what library implements it or where it lives on your hard drive. You will have to consult the documentation for OutOfRange, the author of it, or yourself.
I can tell you that you will want to check:
right click the executable project->
properties->linker->general->additional library directories
properties->linker->input->additional dependencies
and make sure the path to the library that defines OutOfRange is in the former and the library name is in the latter.
EDIT: If the library itself has a header that imports it, as it appears from the code you posted, you just need to set up the additional directories part.
In the end, you have to consult the documentation for whatever library you are using or hit up their forums.
I am not sure but this may be related to your solution configuration and solution platform. It wasn't working for me, when I set my solution configuration to "Debug" and platform to "x64"; it started working after setting it to Release - x86

error LNK2019: unresolved external symbol error

I'm getting these error messages
2>main.obj : error LNK2019: unresolved external symbol "public: __thiscall CEngine::CEngine(void)" (??0CEngine##QAE#XZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall CEngine::SetWindowSize(int,int,char const *,int)" (?SetWindowSize#CEngine##QAEXHHPBDH#Z) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall CEngine::Begin(void)" (?Begin#CEngine##QAEXXZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: int __thiscall CEngine::GetDisplayWidth(void)" (?GetDisplayWidth#CEngine##QAEHXZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: int __thiscall CEngine::GetDisplayHeight(void)" (?GetDisplayHeight#CEngine##QAEHXZ) referenced in function _WinMain#16
2>C:\Users\ethan\Desktop\C++ Projects\delveenginetest\Debug\delveenginetest.exe : fatal error LNK1120: 5 unresolved externals
This is my solution:
Solution 'delveenginetest' (2 projects)
DelveEngine
Include
delve.h
Engine.h
SetupSDL.h
stdafx.h
Engine.cpp
Main.cpp
SetupSDL.cpp
This is the code for Engine.h
#pragma once
#include "SetupSDL.h"
class CEngine
{
public:
CEngine(void);
~CEngine(void);
void SetWindowSize(int winW, int winH, const char* GameName, int windowMode);
void Begin(void);
int GetDisplayWidth(void);
int GetDisplayHeight(void);
private:
int deskW;
int deskH;
bool playing;
CSetupSDL* sdl_setup;
};
Code for Engine.cpp
#include "Include/stdafx.h"
#include "Include/Engine.h"
CEngine::CEngine(void)
{
playing = true;
deskW = GetSystemMetrics(SM_CXSCREEN);
deskH = GetSystemMetrics(SM_CYSCREEN);
}
CEngine::~CEngine(void)
{
}
void CEngine::SetWindowSize(int winW, int winH, const char* GameName, int windowMode)
{
// set up SDL for use
sdl_setup = new CSetupSDL(winW, winH, GameName, windowMode);
}
void CEngine::Begin(void)
{
while (playing && sdl_setup->GetMainEvent()->type != SDL_QUIT)
{
sdl_setup->Begin();
sdl_setup->End();
}
playing = false;
}
int CEngine::GetDisplayWidth(void){ return deskW; }
int CEngine::GetDisplayHeight(void){ return deskH; }
The DelveEngine project builds successfully, whereas the delveenginetest project fails.
What's wrong? I've looked everywhere for a reason, can't find one that suits me.
Despite the fact you're not providing all the sufficient information for a correct diagnosis of your problems, I'll try to share what I could imagine that might be the reasons for the linker errors:
I suppose the project delveenginetest you mention is meant to set up unit tests for the classes from the DelveEngine project.
Since you have a Main.cpp in your DelveEngine project, I'd guess it's simply build as an executable (successfully).
Your delveenginetest needs to link to the classes provided from the DelveEngine project, but that's actually not possible, since the .exe from DelveEngine can't be used for linking, you'll need a library to import it to another executable (the unit testing framework).
I'd recommend to separate out your classes/source files from DelveEngine project to make up a static or shared library, that can be linked from an application and the test framework simultaneously from within a single VS solution:
Solution 'DelveEngine' (3 projects)
DelveEngineLib (project [.lib/.dll])
Include
delve.h
Engine.h
SetupSDL.h
Engine.cpp
SetupSDL.cpp
DelveEngine (project [.exe])
Main.cpp
delveenginetest (project [.exe])
Main.cpp (TestFramework main definition)
Since I'm not very versed with it I don't know actually, if VS 2013 supports to setup projects consuming virtual resources (think of links to sources in the actual build environment), but this could be an alternative how to setup application and unit tests without need of an extra library.

How to solve error LNK2019: unresolved external symbol error in Visual Studio 2012 with C++?

I have a visual c++ console project named "C_test".
Another project is called "dll_project" which is dll project.
in "C_test" project, I have set the location of additional include directory for "dll_project".
I have these simple codes.
in "C_test" project's main.cpp.
#include "SampleClass.h"
int main()
{
SampleClass *_parser = new SampleClass();
return 0;
}
And in "dll_project" SampleClass.h and SampleClass.cpp.
SampleClass.h
#pragma once
class SampleClass
{
public:
SampleClass(void);
~SampleClass(void);
};
SampleClass.cpp
#include "SampleClass.h"
SampleClass::SampleClass(void)
{
}
SampleClass::~SampleClass(void)
{
}
When I try to debug or build, I get this error.
error LNK2019: unresolved external symbol "public: __thiscall SampleClass::SampleClass(void)" (??0SampleClass##QAE#XZ) referenced in function _main C:\C_test\main.obj C_test
What have I done wrong?

Visual studio 2013, unresolved external symbol error when working with local source library (pugixml)

I'm attempting to use the pugiXML library to read some XML, and I can't get it to compile correctly. After moving the source files(3) into the working directory, bringing them into the project, and disabling the use of precompiled headers, I have been having a hard time trying to get it to link and build.
These are the snippets giving me problems:
// XMLAdapter.h
#pragma once
#include "pugixml.hpp"
using namespace pugi;
class XMLAdapter
{
private:
static xml_document doc;
static bool isReady;
static xml_parse_result result;
public:
static void setResource(char* resource);
template <typename T> static T getItems(char* xpath, T (*getThings)(xpath_node_set*));
};
.
// XMLAdapter.cpp
#include "stdafx.h"
#include "XMLAdapter.h"
bool XMLAdapter::isReady = false;
void XMLAdapter::setResource(char* resource){
XMLAdapter::result = XMLAdapter::doc.load_file(resource);
XMLAdapter::isReady = true;
}
and the errors:
Error 1 error LNK2001: unresolved external symbol "private: static
class pugi::xml_document XMLAdapter::doc"
(?doc#XMLAdapter##0Vxml_document#pugi##A) C:\Users\Adam\SkyDrive\Documents\proj\ray\ray\XMLAdapter.obj ray
Error 2 error LNK2001: unresolved external symbol "private: static
struct pugi::xml_parse_result XMLAdapter::result"
(?result#XMLAdapter##0Uxml_parse_result#pugi##A) C:\Users\Adam\SkyDrive\Documents\proj\ray\ray\XMLAdapter.obj ray
Error 3 error LNK1120: 2 unresolved
externals C:\Users\Adam\SkyDrive\Documents\proj\ray\Debug\ray.exe 1 1 ray
I'm fairly new to C++, so any advice would be welcome;

C++ LNK2019 error with constructors and destructors in derived classes

I have two classes, one inherited from the other. When I compile, I get the following errors:
Entity.obj : error LNK2019: unresolved external symbol "public: __thiscall Utility::Parsables::Base::Base(void)" (??0Base#Parsables#Utility##QAE#XZ) referenced in function "public: __thiscall Utility::Parsables::Entity::Entity(void)" (??0Entity#Parsables#Utility##QAE#XZ)
Entity.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall Utility::Parsables::Base::~Base(void)" (??1Base#Parsables#Utility##UAE#XZ) referenced in function "public: virtual __thiscall Utility::Parsables::Entity::~Entity(void)" (??1Entity#Parsables#Utility##UAE#XZ)
D:\Programming\Projects\Caffeine\Debug\Caffeine.exe : fatal error LNK1120: 2 unresolved externals
I really can't figure out what's going on.. can anyone see what I'm doing wrong? I'm using Visual C++ Express 2008. Here are the files..
"include/Utility/Parsables/Base.hpp"
#ifndef CAFFEINE_UTILITY_PARSABLES_BASE_HPP
#define CAFFEINE_UTILITY_PARSABLES_BASE_HPP
namespace Utility
{
namespace Parsables
{
class Base
{
public:
Base( void );
virtual ~Base( void );
};
}
}
#endif //CAFFEINE_UTILITY_PARSABLES_BASE_HPP
"src/Utility/Parsables/Base.cpp"
#include "Utility/Parsables/Base.hpp"
namespace Utility
{
namespace Parsables
{
Base::Base( void )
{
}
Base::~Base( void )
{
}
}
}
"include/Utility/Parsables/Entity.hpp"
#ifndef CAFFEINE_UTILITY_PARSABLES_ENTITY_HPP
#define CAFFEINE_UTILITY_PARSABLES_ENTITY_HPP
#include "Utility/Parsables/Base.hpp"
namespace Utility
{
namespace Parsables
{
class Entity : public Base
{
public:
Entity( void );
virtual ~Entity( void );
};
}
}
#endif //CAFFEINE_UTILITY_PARSABLES_ENTITY_HPP
"src/Utility/Parsables/Entity.cpp"
#include "Utility/Parsables/Entity.hpp"
namespace Utility
{
namespace Parsables
{
Entity::Entity( void )
{
}
Entity::~Entity( void )
{
}
}
}
The relevant bit is this:
unresolved external symbol "public: __thiscall Utility::Parsables::Base::Base(void)"
You need to provide a definition for Base::Base and Base::~Base. A declaration is not good enough. Even if you have nothing to do in either function, you need to leave an empty function body, because C++ actually requires the function to exist. C++ puts things like virtual table maintenance inside your constructors and destructors, so they must be defined even if you don't need to do anything there -- C++ has to do things in there.
Are you sure Base.cpp is being included in the build?
Just encountered this exact same error today in Visual Studio 2015. Unfortunately the accepted answer didn't worked (as well as answers from many same questions). The thing that worked for me was right click on the base class cpp file, exclude and then include it again. I think somehow VS got confused while moving file around and renames and it just silently refused to compile it even though it was marked as "Included In project" = true in property editor as well as listed in vcproj file in group. This is horrible error and ended up spending good hour on it.
Either your base.cpp is not being compiled/linked or you have a misspelling in it