Referencing 3rd party librarys

[dex668]

Hi,

I have for a number of weeks been trying to integrate several third party librarys into a C++ application with no success, i'm sure the error is fairly simple, but i cannot for the life of me figure it out!

Libs:
- ccrtp
- jrtplib
- toast gsm

I always get 'undefined reference (...)' errors for any of the member functions i try to use. I'm using Fedora Core 3, g++ though the Eclipse IDE.

my compile line options would appear to be:
g++ -I/usr/local/include -O0 -g3 -Wall -c -fmessage-length=0 -lpthread -lthreads

I have followed all the install instructions for these libs including ./configure, make, make install, etc.

I'm not very experienced with linux so if anyone could shed any light on this it would be extremely helpful!

Thank you all!

-Dex

---------------------
Example code snippet: AudioCodec.cpp

#include "AudioCodec.h"

#include <gsm/gsm.h>

/* Project includes */
#include "Global.h"
#include "SystemLogger.h"

gsm handle;
gsm_frame buf;
gsm_signal sample[160]; 
int cc, soundfd;

AudioCodec::AudioCodec()
{
		systemLogger = &SystemLogger::getInstance();	
}

AudioCodec::~AudioCodec()
{
}

int AudioCodec::decode()
{
	return decode(0);
}

int AudioCodec::decode( int codec )
{
	switch (codec)
	{
		case 0: 
			// gsm decode 
			if (!(handle = gsm_create())) 
*ERROR: undefined reference to `gsm_create()'	AudioCodec.cpp	server	line 34	05 January 2005 14:51:58

			{
				printf("Error: Unable to create GSM decoder");
				return 0;
			}
			
            if (gsm_decode(handle, buf, sample) < 0) return 0;
*ERROR: undefined reference to `gsm_decode(gsm_state*, unsigned char*, short*)'	AudioCodec.cpp	server	line 40	05 January 2005 14:51:58

 
            gsm_destroy(handle);
ERROR: undefined reference to `gsm_destroy(gsm_state*)'	AudioCodec.cpp	server	line 42	05 January 2005 14:51:58

			
			break;
		default:
			systemLogger->addToSystemLog("AudioCodec::No codec selected");
			printf("Error: No codec selected");
	}
	
	return 0;
}

 

[Salem]

> g++ -I/usr/local/include -O0 -g3 -Wall -c -fmessage-length=0 -lpthread -lthreads
You need more libraries, and possibly some library paths depending on where your "make install" put the 3rd party libraries.

If you have say "libfoo.a" in some non-standard library directory, then the command line would become
[tt]g++ -I/usr/local/include -O0 -g3 -Wall -c -fmessage-length=0 -lpthread -lthreads -L/path/to/library -lfoo[/tt]

The [tt]-lfoo[/tt] specifies a library called libfoo.a
The [tt]-L/path/to/library[/tt] tells the linker where libfoo.a can be found.

--

 

[dex668]

Salem, thanks for your prompt reply, it's much appreciated.

I have tried doing as you suggest, adding -lgsm to the compile path. However the same errors persist.

I have removed references to all libraries apart from the GSM one. i have also checked my system folders, the relevant files do exist:

- /usr/local/lib
- libgsm.a
- /usr/local/include/
- /gsm/gsm.h

below is the output from my eclipse based compilation:



**** Incremental build of configuration Debug for project server ****

make -k all
Building file: ../AudioCodec.cpp
g++ -I/usr/local/include -O0 -g3 -Wall -c -fmessage-length=0 -lpthread -lthreads -lgsm -o AudioCodec.o ../AudioCodec.cpp
g++: -lpthread: linker input file unused because linking not done
g++: -lthreads: linker input file unused because linking not done
g++: -lgsm: linker input file unused because linking not done
g++: -lpthread: linker input file unused because linking not done
g++: -lthreads: linker input file unused because linking not done
g++: -lgsm: linker input file unused because linking not done
Finished building: ../AudioCodec.cpp

Building target: server
g++ -L/usr/local/lib -o server AdminConn.o AdminCore.o AudioCodec.o AudioConn.o ClientThread.o Core.o DataConn.o GSM.o Interpreter.o Multiplexer.o PlugIn.o SystemLogger.o main.o -lpthread -lgsm -lthreads
/usr/bin/ld: warning: libstdc++.so.5, needed by /usr/local/lib/libthreads.so, may conflict with libstdc++.so.6
AudioCodec.o(.text+0x10c): In function `AudioCodec::decode(int)':
../AudioCodec.cpp:35: undefined reference to `gsm_create()'
AudioCodec.o(.text+0x14b):../AudioCodec.cpp:41: undefined reference to `gsm_decode(gsm_state*, unsigned char*, short*)'
AudioCodec.o(.text+0x169):../AudioCodec.cpp:43: undefined reference to `gsm_destroy(gsm_state*)'
collect2: ld returned 1 exit status
make: *** [server] Error 1
make: Target `all' not remade because of errors.
Build complete for project server


Thank you again for your help.

Dex

 

[dex668]

Thanks for your help Salem, i appear to have resolved the issue, the file permissions on the lib file were messed up meaning g++ couldnt access it during compilation.

Cheers,

Dex