I'm having some trouble compiling a basic program using RtMidi on OS X. I initially tried using XCode and adding the library as a target, then I tried a simpler compilation using g++. The same errors were returned in each instance.
Here's the command and output:
$ g++ -Wall -D __MACOSX_CORE__ -o midiprobe midiprobe.cpp -framework CoreAudio -framework CoreFoundation -lpthread
Undefined symbols for architecture x86_64:
"RtMidiIn::RtMidiIn(RtMidi::Api, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, unsigned int)", referenced from:
_main in midiprobe-d2b0ea.o
"RtMidiOut::RtMidiOut(RtMidi::Api, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >)", referenced from:
_main in midiprobe-d2b0ea.o
ld: symbol(s) not found for architecture x86_64
This is my first time using a library in this manner, so some pointers in the right direction would be appreciated. Thanks!
Related
$clang++ main.cpp -o out
Got following error, the same error happens when changing to g++. I have tested on some simple simple c++ code, the command works fine. So it the problem in that PNG class file? However, the same files worked on my MacOS before, but suddenly failed today.
Undefined symbols for architecture x86_64:
"PNG::writeToFile(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
_main in main-f6a06a.o
"PNG::PNG(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
_main in main-f6a06a.o
"PNG::PNG(unsigned long, unsigned long)", referenced from:
_main in main-f6a06a.o
"PNG::~PNG()", referenced from:
_main in main-f6a06a.o
"PNG::operator()(unsigned long, unsigned long)", referenced from:
_main in main-f6a06a.o
"PNG::width() const", referenced from:
_main in main-f6a06a.o
"PNG::height() const", referenced from:
_main in main-f6a06a.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Did you miss providing static/shared to the linker to resolve the linker errors for the methods mentioned? Also note that clang++ is a different compiler compared to g++ and hence need the static/shared libraries compiled prior by the same compiler you are using (clang++).
Try:
clang++ main.cpp -o out -lpng
Here's why: You are not providing the library that contains the implementation of your PNG library (libpng most likely). You need -lpng added to your compiler, so that it links with the relevant library. It may not be exactly -lpng in your particular case, but it's definitely a "missing library". Without knowing exactly what library you are trying to use (you didn't provide some source to "try the fix with").
As pointed out in the comment: you are using some kind of C++ wrapper on top, the above is probably not enough - but without knowing exactly which C++ wrapper on the png functionality you are actually using, it's hard to say what the command-line should look like.
Perhaps this
I understand what an unresolved symbol error is, but I don't understand why I'm getting it in this particular situation with this particular library. Here is the output of the error.
Undefined symbols for architecture x86_64:
"soci::soci_error::soci_error(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
soci::type_conversion<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, void>::from_base(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, soci::indicator, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&) in Inspector.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Note that I am using the following link flags:
-L/usr/local/lib -lsoci_core -lsoci_postgresql -lpq -ldl
Note also that references to other symbols (e.g., the soci::session constructor and destructor) are being resolved.
What am I doing wrong? Is there another soci library that I should also be linking against?
EDIT: Note that I am working on Mac OS X, and have tried both the installation through homebrew (via brew install soci --with-pg), and the standalone installations of 3.2.2 and 3.2.1.
I don't know why this solved the error, but changing from libc++ to libstdc++ resolved it.
I'm trying to compile the Sam Hare's Struck code.
I'm using mac OSX10.9, opencv 2.4.6 and Eigen 2.0.17.
Eigen and opencv headers are stored in /opt/local/include while opencv dylib in /opt/local/lib.
I modified the Hare's Makefile to work on this folder. When I type make on the terminal:
g++ -L/opt/local/lib -lopencv_core -lopencv_highgui -lopencv_imgproc src/Config.o src/Features.o src/HaarFeature.o src/HaarFeatures.o src/HistogramFeatures.o src/ImageRep.o src/LaRank.o src/MultiFeatures.o src/RawFeatures.o src/Sampler.o src/Tracker.o src/main.o src/GraphUtils/GraphUtils.o -o struck
I get these errors:
Undefined symbols for architecture x86_64:
"cv::namedWindow(std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> > const&,
int)", referenced from:
_main in main.o "cv::split(cv::Mat const&, std::__1::vector<cv::Mat, std::__1::allocator<cv::Mat> >&)",
referenced from:
ImageRep::ImageRep(cv::Mat const&, bool, bool, bool) in ImageRep.o "cv::imread(std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> > const&,
int)", referenced from:
_main in main.o "cv::imshow(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&,
cv::_InputArray const&)", referenced from:
LaRank::Debug() in LaRank.o
Tracker::Debug() in Tracker.o
_main in main.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see
invocation)
Any ideas? Thanks!
I had a similar warning/error/failure when I was simply trying to make an executable from two different object files (main.o and add.o). I was using the command:
gcc -o exec main.o add.o
But my program is a C++ program. Using the g++ compiler solved my issue:
g++ -o exec main.o add.o
I was always under the impression that gcc could figure these things out on its own. Apparently not. I hope this helps someone else searching for this error.
finally solved my problem.
I created a new project in XCode with the sources and changed the C++ Standard Library from the default libc++ to libstdc++ as in this and this.
I am getting the same error. I don't think it is a "fix", but my work-around is to also include the cpp file. So instead of just putting
#include "MyClass.h"
I have to put
#include "MyClass.h"
#include "MyClass.cpp"
I wrote my declarition in the .h file
class String
{
String (const char * cstr = 0);
};
and I used inline in another .cpp file (implementation)
inline String::String(const char * cstr)
{
//code ...
}
then I use g++ and get this:
Undefined symbols for architecture x86_64:
"String::String(char const*)", referenced from:
_main in test-d389f3.o
ld: symbol(s) not found for architecture x86_64
solution: do not write inline when declarition and implementation is independent.
When I using clang to compile a C++ program, I have the similar error.
But after I changing to use chang++, the compilation worked.
I have setup OpenCV2 in XCode but unfortunately imshow does not work:
Undefined symbols for architecture x86_64:
"cv::imshow(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, cv::_InputArray const&)", referenced from:
_main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I am running OS X 10.8.4 with latest XCode.
I have attached a few images below to show the setup in XCode and the libraries.
So far it seems that other functions work fine with OpenCV, except this.
I'm going to go out on a limb and say that you compiled OpenCV2 with libstdc++, and are now compiling your application with libc++ support.
You need to compile OpenCV2 with the same C++ library, otherwise it will not be able to link.
if you do an nm of the OpenCV2 library, if it was compiled with libstdc++, it will look like:
cv::imshow(std::string const&, cv::_InputArray const&)
while if it was compiled with libc++, it would look like:
cv::imshow(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, cv::_InputArray const&)
to get the demangled symbol do:
nm library | c++filt | grep cv::imshow
I'm trying to use Poco C++ library to do the simple http requests in C++ on Mac OS X 10.8.2. I installed Poco, copy-pasted the http_request.cc code from this tutorial, ran it with 'g++ -o http_get http_get.cc -lPocoNet', but got:
Undefined symbols for architecture x86_64:
"Poco::StreamCopier::copyStream(std::basic_istream<char, std::char_traits<char> >&, std::basic_ostream<char, std::char_traits<char> >&, unsigned long)", referenced from:
_main in ccKuZb1g.o
"Poco::URI::URI(char const*)", referenced from:
_main in ccKuZb1g.o
"Poco::URI::~URI()", referenced from:
_main in ccKuZb1g.o
"Poco::URI::getPathAndQuery() const", referenced from:
_main in ccKuZb1g.o
"Poco::URI::getPort() const", referenced from:
_main in ccKuZb1g.o
"Poco::Exception::displayText() const", referenced from:
_main in ccKuZb1g.o
"typeinfo for Poco::Exception", referenced from:
GCC_except_table1 in ccKuZb1g.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
Have been struggling with this for couple of hours. Any idea how to fix this? Thanks in advance!
the Poco::URI, Poco::StreamCopier classes are in the PocoFoundation library, so you will need to link to that library also.
g++ -o http_get http_get.cc -lPocoNet -lPocoFoundation
You don't appear to have specified the include path for the library and the library to use when compiling your source.
You need to provide the -I and the -L directive to g++ to specify the include path for the library and the library itself respsectively.