Problems linking libraries

[yaustar]

Hiya,

Tried compiling several demos and its all fine till I reach any that needs libraries (eg OpenGL).

Errors I get are:
Main.cpp     undefined reference to 'glViewport@16'
Main.cpp     undefined reference to 'glMatrixMode@4'
etc

I have tried linking them under
Project -> Build Options -> Linker (under both release and debug and root)

Also the code has

Code

#pragma comment(lib, "opengl32.lib")
#pragma comment(lib, "glu32.lib")

So I cant see whats wrong.... can someone give me a step by step guide in case I am missing anything stupid...

Thanks

[thomas]

Those are libraries you need to link with to build basic OpenGL applications.

Either add -lopengl32 -lglu32 to "other linker options", or add opengl32 and glu32 to link libraries on the left, or link against opengl32.dll and glu32.dll which are both found inside WINDOWS\system32.

[yaustar]

Those are libraries you need to link with to build basic OpenGL applications.

Either add -lopengl32 -lglu32 to "other linker options", or add opengl32 and glu32 to link libraries on the left, or link against opengl32.dll and glu32.dll which are both found inside WINDOWS\system32.

Ooooookay.... the -lopengl32 and -lglu32 in other linker options worked.... my next question is why and what does it actually do when you do that?

[rickg22]

-l is the GCC command to link a library. For some reason adding them to the linker libraries list didn't work in your case.... (weird)

[mandrav]

-l is the GCC command to link a library. For some reason adding them to the linker libraries list didn't work in your case.... (weird)

It's not exactly "weird"...
He used #pragmas to link the libraries. These only work in MS compilers...

[yaustar]

I did link them under Linker -> Link Libraries as well but that didn't work either.. I was wondering if it would be due to importing of options and settings from a VC++ 6.0 workspace...

I am also having similar problems with another set of libraries but since it is a custom built set, it may be better to ask the author instead.

[thomas]

Probably not. Adding them to link libraries does exactly the same thing as -lopengl32 -lglu32, except that you can select an full pathname with a GUI file selector. But then, linking is a black art, so no guarantees.

[rickg22]

Ok... let's see...

1) Search for the libraries you're linking, using windows xp's Find (in start menu). It may take a while, tho.
2) Make sure the directories where these files are located, are included in the "Linker directories".
3) Make sure the libraries are included in the "Link libraries".
4) Rebuild.

[yaustar]

1) Search for the libraries you're linking, using windows xp's Find (in start menu). It may take a while, tho.
> C:\Program Files\CodeBlocks\lib

2) Make sure the directories where these files are located, are included in the "Linker directories".
> Compile -> Compiler Settings -> GNU GCC Compiler -> Linker tab ->  C:\Program Files\CodeBlocks\lib

3) Make sure the libraries are included in the "Link libraries".
> Check

4) Rebuild.
> Still the same problem

[thomas]

Out of curiosity, does it work if you add absolute paths?
e.g.:
C:\Program Files\CodeBlocks\lib\opengl32.lib
C:\Program Files\CodeBlocks\lib\glu32.lib

[yaustar]

Relative or Absolute paths didn't work either... I haven't tried a 'clean' install of codeblocks through, I just installed the latest version over an older one... .could this be a cause?

edit changed have to haven't

[squizzz]

Which compiler are you actually trying to use...?
Half of the post in this thread suggest it's VC Toolkit (you use #pragmas, *.libs) , other ones that it might be GCC. ("the -lopengl32 and -lglu32 in other linker options worked....")
It's quite confusing.

[yaustar]

Sorry, I am using the GCC compiler, it's just the source is an example tutorial. I didn't know the #pragma was VC only

[squizzz]

Sorry, I am using the GCC compiler, it's just the source is an example tutorial. I didn't know the #pragma was VC only

Okay, as I understand "-lopengl32 -lglu32" solves your problems, but you want link libraries via GUI interface?
If so, you should add libopengl32.a and libglu32.a (you can locate these in MinGW /lib subdirectory) instead of opengl32.lib & glu32.lib.
It comes to any other lib as well, if you were linking foo.lib in your VC 6.0, you will link libfoo.a while using MinGW compiler.

Hope this solves your problem.
Greetz.

[mandrav]

Sorry, I am using the GCC compiler, it's just the source is an example tutorial. I didn't know the #pragma was VC only

Okay, as I understand "-lopengl32 -lglu32" solves your problems, but you want link libraries via GUI interface?
If so, you should add libopengl32.a and libglu32.a (you can locate these in MinGW /lib subdirectory) instead of opengl32.lib & glu32.lib.
It comes to any other lib as well, if you were linking foo.lib in your VC 6.0, you will link libfoo.a while using MinGW compiler.

Or just use foo as a link library and it will be replaced by C::B depending on the used compiler, i.e. libfoo.a vs foo.lib.

[yaustar]

Whoops... didn't realise that there were already libraries for opengl as *.a.. that fixes the promblems nicely...

Now my next problem is using someones elses *.lib for the GCC compiler, would I have to recompiler it to a *.a file or use the *.lib with VC++ compiler?

[squizzz]

Now my next problem is using someones elses *.lib for the GCC compiler, would I have to recompiler it to a *.a file or use the *.lib with VC++ compiler?

It depends. Most of 3rd party libraries comes with precompiled binaries for all major compiler suites. The good news is that GCC/MinGW is one of them. Usually you can download them as separate packages (one for VC++, one for GCC, other for Borland etc).

Btw. many libraries are addictionally released as so called devpaks, you can find huge repository of these at: http://devpaks.org (the site seems to be down ATM...) or download 'em via DevPak plugin. These are dedicated to GCC/MinGW compiler.

[yaustar]

Thanks for the information. It saves me a lot of running around headless...

[Joker]

I'm having similar problems, without resolve.

I'm tinkering with OGRE templates, and I am unable to get code::blocks to have it link with the libraries. I've tried .net toolkit 2003 compiler, and the provided mingw. all give similar unresolved errors. Now, in the projects build options, I've set a FULL path to the libraries in question (OgreMain(_d) in this case) with the same result. I've also tried it with the -l gcc option in extra link options in the same dialog, same result.

i can't seem to figure this out. its very strange.. here's some screenshots:

using gcc: (i've tried every possible combo here)
http://img106.imagevenue.com/img.php?loc=loc153&image=82a_linker_gcc.JPG

using vc .net toolkit
http://img15.imagevenue.com/img.php?loc=loc81&image=595_linker_vc.JPG

always getting unresolved ogre symbols.


btw, the code is just unmodified template privided with code::blocks.

[tiwag]

... I am unable to get code::blocks to have it link with the libraries
... i can't seem to figure this out. its very strange.. here's some screenshots:
...

the screenshots were a good idea : sit back and READ carefully what's written on the screen !
Policy: Use project options only
this means, that all settings from this dialog box are NOT USED to build this target !

set Policy to any of the other possible settings, like "Prepend target options to project options" and try again ;-)

[Joker]

if you notice, VC is on the default setting (Append settings to project default). I still get the link errors, reguardless. I was desperate, and its not that :-P

I took the screeny after messing with pretty much every setting trying to get it to work.

[mandrav]

You know, if you 'd post the build log you might get more helpful replies. A simple "I get unresolved ogre symbols" means nothing...
And before posting your build log, go to "Settings->Compiler->[select compiler]->Other" and set "Compiler logging" to full command-line.

[Joker]

VC build log:

Project   : OGRE_Sample
Compiler  : Microsoft Visual C++ Toolkit 2003 (called directly)
Directory : E:\Coding\
--------------------------------------------------------------------------------
Switching to target: Debug
cl.exe /nologo   /GX /Zi /DDEBUG /D_DEBUG    /IE:\Coding\OgreSDK\include /IE:\Coding\OgreSDK\include\opt /IE:\Coding\OgreSDK\Samples\include  /I"C:\Program Files\Microsoft Visual C++ Toolkit 2003\include" /c main.cpp /FoDebug\.objs\main.obj
main.cpp
link.exe /nologo   /LIBPATH:E:\Coding\OgreSDK\lib /LIBPATH:E:\Coding\OgreSDK\lib\opt\debug  /LIBPATH:"C:\Program Files\Microsoft Visual C++ Toolkit 2003\lib" /out:Debug\ogre_sample.exe   user32.lib kernel32.lib gdi32.lib opengl32.lib OgreMain_d.lib  Debug\.objs\main.obj     
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall Ogre::Exception::getFullDescription(void)const " (__imp_?getFullDescription@Exception@Ogre@@QBE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ) referenced in function $L130547
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall Ogre::Root::Root(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (__imp_??0Root@Ogre@@QAE@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@00@Z) referenced in function "protected: virtual bool __thiscall ExampleApplication::setup(void)" (?setup@ExampleApplication@@MAE_NXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class Ogre::RenderWindow * __thiscall Ogre::Root::initialise(bool,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (__imp_?initialise@Root@Ogre@@QAEPAVRenderWindow@2@_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "protected: virtual bool __thiscall ExampleApplication::configure(void)" (?configure@ExampleApplication@@MAE_NXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class Ogre::Overlay * __thiscall Ogre::OverlayManager::getByName(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (__imp_?getByName@OverlayManager@Ogre@@QAEPAVOverlay@2@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "public: __thiscall ExampleFrameListener::ExampleFrameListener(class Ogre::RenderWindow *,class Ogre::Camera *,bool,bool)" (??0ExampleFrameListener@@QAE@PAVRenderWindow@Ogre@@PAVCamera@2@_N2@Z)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Ogre::StringConverter::toString(class Ogre::Vector3 const &)" (__imp_?toString@StringConverter@Ogre@@SA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABVVector3@2@@Z) referenced in function "public: virtual bool __thiscall ExampleFrameListener::processUnbufferedKeyInput(struct Ogre::FrameEvent const &)" (?processUnbufferedKeyInput@ExampleFrameListener@@UAE_NABUFrameEvent@Ogre@@@Z)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Ogre::StringConverter::toString(class Ogre::Quaternion const &)" (__imp_?toString@StringConverter@Ogre@@SA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABVQuaternion@2@@Z) referenced in function "public: virtual bool __thiscall ExampleFrameListener::processUnbufferedKeyInput(struct Ogre::FrameEvent const &)" (?processUnbufferedKeyInput@ExampleFrameListener@@UAE_NABUFrameEvent@Ogre@@@Z)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const & __thiscall Ogre::RenderTarget::getDebugText(void)const " (__imp_?getDebugText@RenderTarget@Ogre@@QBEABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ) referenced in function "protected: void __thiscall ExampleFrameListener::updateStats(void)" (?updateStats@ExampleFrameListener@@IAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Ogre::StringConverter::toString(unsigned int,unsigned short,char,int)" (__imp_?toString@StringConverter@Ogre@@SA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@IGDH@Z) referenced in function "protected: void __thiscall ExampleFrameListener::updateStats(void)" (?updateStats@ExampleFrameListener@@IAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Ogre::StringConverter::toString(unsigned long,unsigned short,char,int)" (__imp_?toString@StringConverter@Ogre@@SA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@KGDH@Z) referenced in function "protected: void __thiscall ExampleFrameListener::updateStats(void)" (?updateStats@ExampleFrameListener@@IAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Ogre::StringConverter::toString(float,unsigned short,unsigned short,char,int)" (__imp_?toString@StringConverter@Ogre@@SA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@MGGDH@Z) referenced in function "protected: void __thiscall ExampleFrameListener::updateStats(void)" (?updateStats@ExampleFrameListener@@IAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class Ogre::OverlayElement * __thiscall Ogre::OverlayManager::getOverlayElement(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,bool)" (__imp_?getOverlayElement@OverlayManager@Ogre@@QAEPAVOverlayElement@2@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@_N@Z) referenced in function "protected: void __thiscall ExampleFrameListener::updateStats(void)" (?updateStats@ExampleFrameListener@@IAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall Ogre::ResourceGroupManager::addResourceLocation(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,bool)" (__imp_?addResourceLocation@ResourceGroupManager@Ogre@@QAEXABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@00_N@Z) referenced in function "protected: virtual void __thiscall ExampleApplication::setupResources(void)" (?setupResources@ExampleApplication@@MAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class Ogre::MapIterator<class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::multimap<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > *,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::multimap<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > > > *> > > > __thiscall Ogre::ConfigFile::getSectionIterator(void)" (__imp_?getSectionIterator@ConfigFile@Ogre@@QAE?AV?$MapIterator@V?$map@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAV?$multimap@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@U?$less@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@@std@@@2@@2@U?$less@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAV?$multimap@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@U?$less@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@@std@@@2@@2@@std@@@2@@std@@@2@XZ) referenced in function "protected: virtual void __thiscall ExampleApplication::setupResources(void)" (?setupResources@ExampleApplication@@MAEXXZ)
main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall Ogre::ConfigFile::load(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,bool)" (__imp_?load@ConfigFile@Ogre@@QAEXABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@0_N@Z) referenced in function "protected: virtual void __thiscall ExampleApplication::setupResources(void)" (?setupResources@ExampleApplication@@MAEXXZ)
main.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME" (__imp_?DEFAULT_RESOURCE_GROUP_NAME@ResourceGroupManager@Ogre@@2V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A)
Debug\ogre_sample.exe : fatal error LNK1120: 15 unresolved externals
Process terminated with status 1 (0 minutes, 5 seconds)
16 errors, 0 warnings
 

gcc is basically the same thing. paths are correct, it is passing the proper OgreMain lib to the linker, its just not linking it.
I'm begining to suspect its ogre..

[mandrav]

Does it happen with the release build too, or only the debug?

[Joker]

both, using either compiler.

[mandrav]

It was the next thing I was going to suggest, but since there's a thread (at Ogre forums) already explaining it, I thought I 'd just post a link.
Take a look at this.