Undefined reference question - c++

Question

When I try compiling this:
#include "OriAudioCache.hpp"
int main()
{
System *audioSystem(0);
FMOD_RESULT result;
result = System_Create(&audioSystem);
FMOD_CHECK_STATE(result);
OriAudioCache cache(audioSystem, 20);
string title("Ambitious Girl");
string path("/home/findrzkeeprz/Desktop/Resources/The_Ambitious_Girl.mp3");
cache.LoadSound(title, path, Default);
vector<OriSound>::iterator v_iter(cache.FindSound(title));
cache.PlaySound(v_iter->sound());
}
Which uses these files:
OriAudioCache.hpp
#ifndef ORI_AUDIO_CACHE_HPP_
#define ORI_AUDIO_CACHE_HPP_
#include "OriSound.hpp"
#include "OriChannel.hpp"
class OriAudioCache
{
public:
OriAudioCache(System *audioSystem, int maxChannels);
~OriAudioCache()
{
vector<OriSound>::iterator v_iter(audioCache_.begin());
for(; v_iter != audioCache_.end(); ++v_iter)
{
v_iter->~OriSound();
}
delete audioSystem_;
}
void LoadSound(string const& title, string const& path, AudioLoadMode mode);
vector<OriSound>::iterator FindSound(string const& title);
void RemoveSound(string const& title);
void PlaySound(Sound* sound);
vector<OriChannel>::iterator RequestChannel(bool &allocStatus, FMOD_CHANNELINDEX &allocMode);
void ReleaseChannel(Channel *channel);
private:
void inline SortChannels() {sort(channels_.begin(),channels_.end());}
vector<OriSound> audioCache_;
vector<OriChannel> channels_;
System *audioSystem_;
};
#endif
and OriAudioCache.cpp
#include "OriAudioCache.hpp"
OriAudioCache::OriAudioCache(System *audioSystem, int maxChannels)
:audioSystem_(audioSystem), channels_(maxChannels){}
void OriAudioCache::LoadSound(string const& title, string const& path, AudioLoadMode mode)
{
OriSound sound(title, path, audioSystem_, mode);
vector<OriSound>::iterator pos =lower_bound(audioCache_.begin(), audioCache_.end(), sound);
audioCache_.insert(pos, sound);
}
vector<OriSound>::iterator OriAudioCache::FindSound(string const& title)
{
vector<OriSound>::iterator v_iter(audioCache_.begin());
for(; v_iter != audioCache_.end(); ++v_iter) //Would better if I could use a binary search here
{
if(v_iter->title() == title) return v_iter;
else continue;
}
return audioCache_.end();
}
void OriAudioCache::RemoveSound(string const& title)
{
vector<OriSound>::iterator v_iter(audioCache_.begin());
for(; v_iter != audioCache_.end(); ++v_iter) //Would better if I could use a binary search here
{
if(v_iter->title() == title) audioCache_.erase(v_iter);
else continue;
}
}
void OriAudioCache::PlaySound(Sound* sound)
{
bool channelAlloc(false);
FMOD_CHANNELINDEX allocMode = FMOD_CHANNEL_FREE;
vector<OriChannel>::iterator oriChannel = RequestChannel(channelAlloc, allocMode);
if(channelAlloc)
{
FMOD_RESULT result;
Channel *chnl = oriChannel->channel();
result = audioSystem_->playSound(allocMode, sound, false, &chnl);
FMOD_CHECK_STATE(result);
bool isPlaying(false);
chnl->isPlaying(&isPlaying);
while(isPlaying)
{
chnl->isPlaying(&isPlaying);
}
bool paused(false);
chnl->getPaused(&paused);
if(!paused)
{
ReleaseChannel(chnl);
}
SortChannels(); //sort channels, reoder for channel requests
}
}
vector<OriChannel>::iterator OriAudioCache::RequestChannel(bool &allocStatus, FMOD_CHANNELINDEX &allocMode)
{
vector<OriChannel>::iterator vOri_iter(channels_.begin());
if(vOri_iter->status() == false)
{
if(vOri_iter->channel() == 0)
{
allocMode = FMOD_CHANNEL_FREE;
vOri_iter->setStatus(true); // flag channel as being used
return vOri_iter;
}
else allocMode = FMOD_CHANNEL_REUSE;
vOri_iter->setStatus(true); // flag channel as being used
return vOri_iter;
}
else return channels_.end();
}
void OriAudioCache::ReleaseChannel(Channel *channel)
{
bool playing(false);
bool paused(false);
channel->isPlaying(&playing);
channel->getPaused(&paused);
if(!playing && !paused)
{
vector<OriChannel>::iterator vOri_iter(channels_.begin());
for(; vOri_iter != channels_.end(); ++vOri_iter)
{
if(vOri_iter->channel() == channel) vOri_iter->setStatus(false);
}
}
}
I get undefined reference errors:
findrzkeeprz#Aardvak:~/Documents/Chidori/Engine/Audio$ make
g++ -ggdb -I../../ -I../../Engine -I../../Include -I../../Public -o audio main.cpp ../../Libraries/FMODEX/libfmodex.so
/tmp/cctNhPVy.o: In function `main':
/home/findrzkeeprz/Documents/Chidori/Engine/Audio/main.cpp:9: undefined reference to `OriAudioCache::OriAudioCache(FMOD::System*, int)'
/home/findrzkeeprz/Documents/Chidori/Engine/Audio/main.cpp:12: undefined reference to `OriAudioCache::LoadSound(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, AudioLoadMode)'
/home/findrzkeeprz/Documents/Chidori/Engine/Audio/main.cpp:13: undefined reference to `OriAudioCache::FindSound(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/home/findrzkeeprz/Documents/Chidori/Engine/Audio/main.cpp:14: undefined reference to `OriAudioCache::PlaySound(FMOD::Sound*)'
collect2: ld returned 1 exit status
make: *** [audio] Error 1
What I'm I doing wrong here?

Answer 1

You're compiling OriAudioCache.hpp, when you should be compiling OriAudioCache.cpp, that's assuming that file that contains the implementation.

Answer 2

In general, the term "Undefined reference" from a compiler (actually the linker) means that some code fragment is accessing a symbol that the linker could not find.
Common causes of these errors:
Source file containing the definition
is not included in the build process.
A source fragment (code lines) were
not removed.
A header file (class declaration)
declares the given method or symbol (which was not removed or needs to be implemented).
Incorrect or missing scope resolution
operator (namespace issue).
Build process using wrong version of
source files (e.g. file not checked
into CMS.).
Most cases of these errors are not about the C++ reference operator nor dereferencing pointers.
Solutions:
Code review by independent eye(s).
Code inspection tools: Cppcheck,
Valgrind, Klocwork, etc.
Make fewer changes, compiler more
often.
Use Test Driven Development. ;-)