Including external libraries in CodeRunner 2 app?

Question

I've always used Xcode to compile OpenCV based code in c++. The procedure in Xcode was quite simple, I just had to mention the paths and add the necessary lib files to the project. Theres this app called CodeRunner 2 for macOS. Theres no proper documentation on how to include external libraries to compile code in this app. Is it possible to link OpenCV headers and compile them in CodeRunner ? If yes, could someone post the steps?

Answer 1

You can run OpenCV in CodeRunner by setting up a new language. Go to Preferences -> Languages, right-click C++, and select Duplicate. Name the new language "C++ OpenCV". On the right side of the preferences window, click Settings then the Edit Script button. Look for this line (or something similar):

xcrun clang++ -x c++ -lc++ -o "$out" "${files[@]}" "${@:1}"

Add the clang++ command line parameters for OpenCV after "$out". Here's my version:

xcrun clang++ -x c++ -lc++ -o "$out" -I/usr/local/opt/opencv3/include -L/usr/local/opt/opencv3/lib -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_imgcodecs -lopencv_videoio -lopencv_calib3d "${files[@]}" "${@:1}"

Modify the -I and -L parameters to match your OpenCV install path. On this machine I used Homebrew to install OpenCV so it was installed in /usr/local/opt. On other machines I've compiled from source so OpenCV is installed in /usr/local/lib.

Modify the -l parameters to include the libraries you typically use.

After saving the compile script, go back to Preferences -> Languages and select the Templates button. You can set up a template for OpenCV programs. Here's mine:

#include <iostream>

#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"

using namespace std;

int main(int argc, char *argv[]) {
    cv::Mat image;
    // read an image
    if (argc < 2)
        image = cv::imread("img.jpg");
    else
        image = cv::imread(argv[1]);

    if (!image.data) {
        std::cout << "Image file not found\n";
        return 1;
    }

    // create image window named "asdfasdf"
    cv::namedWindow("asdfasdf");
    // show the image on window
    cv::imshow("asdfasdf", image);
    // wait for key
    cv::waitKey(0);

    return 0;
}

Answer 2

The previous reply by SSteve is great and also helps me sort out linking Boost library in CodeRunner.

Because the solution in the previous reply is specific to OpenCV library, a carelessly adding to the clang++ command line for external libraries in general might just generate massive building errors, which was the case when I tried to link Boost library.

Here, I want to clarify the unclear bit in SSteve's reply so everyone knows how and where to modify the command line before compiling their code with external library in Mac OS system.

I will use my case to explain, but in some point I will inform you of the tricky bits in CodeRunner setting or general command line typing.

I use macport to install the Boost library by

sudo port install boost

• header file is located at /opt/local/include
• library is located at /opt/local/lib/

If you cannot find the specific sub-library in Boost, open your terminal and type

cd /opt/local/lib/
find . -iname "*boost*"

and you should see all sub-libraries of Boost ( static library ends with .a and dynamic library ends with .dylib ) as below.

Before you start to modify the original command line ( supporting c++ 14 version ) such as

xcrun clang++ -x c++ -std=c++14 -stdlib=libc++ -lc++ -o "$out" "${files[@]}" "${@:1}" ${CR_DEBUGGING:+-g}

you need to know the directory of header file is after -I and the directory of Boost library is after -L, like

-I /opt/local/include/
-L /opt/local/lib/

In order to use a compiled static or dynamic sub-library in Boost ( see figure above ), you have to include it specifically after -L /opt/local/lib/. However, simply copying the library name without file extension either .a or .dylib would never let CodeRunner find the library you expect to run !!!

The detail is explained here and I just quota the important bit below

clang -dynamiclib -o libtest.dylib file1.o file2.o -L/some/library/path -lname_of_library_without_lib_prefix

To run such an example code in Boost Quickstart Document

#include <boost/regex.hpp>
#include <iostream>
#include <string>

int main()
{
    std::string line;
    boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" );

    while (std::cin)
    {
        std::getline(std::cin, line);
        boost::smatch matches;
        if (boost::regex_match(line, matches, pat))
            std::cout << matches[2] << std::endl;
    }
}

the way to include <boost/regex.hpp> now is by

xcrun clang++ -x c++ -std=c++14 -stdlib=libc++ -lc++ -o "$out" -I /opt/local/include/ -L /opt/local/lib -lboost_regex-mt "${files[@]}" "${@:1}" ${CR_DEBUGGING:+-g}

By using this command line, you should be able to compile the example code with Boost library.

Just remember to replace the prefix -lib with -l and exclude the file extension in the command line.

At last, there are some alternative solution to include the external library by using Xcode, which is in here