Linker error when compiling multiple source files in XCode

Hi all,

I’ve been recently trying to build on top of some Urho3D sample code; specifically ‘36_Urho2DTileMap’. At the most basic level, I have been trying to add a player class which can then interact with the 2D background.

Here is the output that I am currently getting (I am running XCode 7.1 [I have also had the same error running on 6.3.2] on Mac OSX 10.10 to build):

[code]Ld Build/bin/gameexe normal x86_64
cd /Users/UrOhNo3D/Desktop/urho2dgame
export MACOSX_DEPLOYMENT_TARGET=10.10
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -L/Users/UrOhNo3D/Desktop/urho2dgame/Build/bin -F/Users/UrOhNo3D/Desktop/urho2dgame/Build/bin -filelist /Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/gameexe.LinkFileList -mmacosx-version-min=10.10 -framework AudioUnit -framework Carbon -framework Cocoa -framework CoreAudio -framework ForceFeedback -framework IOKit -framework OpenGL -framework CoreServices -Wl,-search_paths_first -Wl,-headerpad_max_install_names /Users/UrOhNo3D/CEED-Internal/native-Build/lib/libUrho3D.a -ldl -Xlinker -dependency_info -Xlinker /Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/gameexe_dependency_info.dat -o /Users/UrOhNo3D/Desktop/urho2dgame/Build/bin/gameexe

duplicate symbol __ZN6Sample14InitTouchInputEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample5StartEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample5SetupEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample4StopEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample10CreateLogoEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample21SetWindowTitleAndIconEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample24CreateConsoleAndDebugHudEv in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol _ui in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZTV6Sample in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZTS6Sample in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZTI6Sample in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol _cache in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample14SetLogoVisibleEb in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6SampleC2EPN6Urho3D7ContextE in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6SampleC1EPN6Urho3D7ContextE in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample13HandleKeyDownEN6Urho3D10StringHashERNS0_7HashMapIS1_NS0_7VariantEEE in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample16HandleTouchBeginEN6Urho3D10StringHashERNS0_7HashMapIS1_NS0_7VariantEEE in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
duplicate symbol __ZN6Sample17HandleSceneUpdateEN6Urho3D10StringHashERNS0_7HashMapIS1_NS0_7VariantEEE in:
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/main.o
/Users/UrOhNo3D/Desktop/urho2dgame/Build/game.build/Debug/gameexe.build/Objects-normal/x86_64/player.o
ld: 18 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)[/code]

Some Googling has led me to believe that this issue relates to the way in which files are included, rather anything syntax-related, and so I think it is reasonable to assume that all other relevant Urho3D files are adequately included.

The source files I have, and the files they include are as follows:
Main.cpp:
#include “main.h”
#include “player.h”

Main.h:
#include “Sample.h”

Player.cpp:
#include “main.h”
#include “player.h”

Player.h:
no includes

In the header files, I also include

#ifndef NAME_OF_FILE_H #define NAME_OF_FILE_H <header_file_contents> #endif to ensure that if they are referenced multiple times, they are not considered as duplicates.

If anybody is able to help me with this, it would be hugely appreciated! Thanks!