I have to use Anaconda provided compilers and their Boost package to compile my C++ code. I have a problem such that I do not know how to link properly during the compilation command.
To begin with: I create a dedicated anaconda env. with the following packages:
- boost-cpp=1.77.0
- compilers=1.3.0
These packages may be found here:
https://anaconda.org/conda-forge/compilers
https://anaconda.org/conda-forge/boost-cpp
Upon env. activation: double check which compiler I use:
$ which g++
/usr/share/miniconda3/envs/MYNAME/bin/g++
And then I would like to compile, but I don't know how to include boost libraries.
When I run:
$ g++ workflow/src/CODE.cpp -o workflow/bin/CODE -lm
Of course I get:
CODE.h:10:10: fatal error: boost/property_tree/info_parser.hpp: No such file or directory
10 | #include <boost/property_tree/info_parser.hpp>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
Nevermind, I have worked it out.
Although it might be useful for others so let's keep the solution in here:
g++ workflow/src/CODE.cpp -o workflow/bin/CODE -I$HOME/miniconda3/envs/MYNAME/include -lm
Related
I am trying to install Armadillo with Homebrew with
brew install armadillo
but when I try to compile with
g++ example.cpp -o example -std=c++11 -O2 -larmadillo
it gives the following error:
fatal error: 'armadillo' file not found
How can I solve this problem?
I'm guessing here that you have a new M1 Mac. The issue in this case is that ARM-native homebrew is installed to /opt/homebrew/ by default, meaning armadillo was installed to /opt/homebrew/include/ which is not in your search path.
To see if this is the case, try providing the paths as follows:
CPATH=/opt/homebrew/include LIBRARY_PATH=/opt/homebrew/lib g++ example.cpp -o example -std=c++11 -O2 -larmadillo
To avoid the issue in general, I'm running with those CPATH and LIBRARY_PATH variables exported in my ~/.zprofile file (using zsh). I found this answer on the apple stack exchange helpful.
I have 2 cpp files(with one main function) in /home/misha/proga/c++again folder. I built C/C++: g++ build active task and modified it to compile all files in the folder above. Now, I need to add one more task to call a binary. I think I should add one more entry in "tasks" to finally be able to run a code. Where can I read about how to write this second task? I am new to programming. Is my approach correct to run this code contained in two files? I also do not know where this binary lies. Is it tasks file in .vscode folder ?
I use Ubuntu 19.10 and VSC 1.46.1
In Terminal,
cd /home/misha/proga/c++again
Let's suppose your two cpp files are mainFile.cpp and file2.cpp
If g++ (so GCC) was not installed in your system, you can install it by running this command on the Terminal:
sudo apt-get install gcc g++
and, to compile the program (read about invoking GCC, you want warnings and debug information), write this command into the Terminal:
g++ -Wall -g mainFile.cpp file2.cpp -o yourprog
Then, you can run the program by typing:
./yourprog
It should work now. You could need to use the GDB debugger and GNU make (to be installed with sudo apt-get install gdb make)
Read also some C++ programming book and this C++ reference.
I do not understand your approach usualy your create a makefile and compile your cpp files
g++ -g -c -fpic -o name.o
at the end you link them
g++ name.o 2name.o and so on
If you create binarys you should store them in /usr/lib
and the name should libname.so you can acces them by using the -l argument
If I write this code and saved as a.cpp at ~/Desktop
#include <memory>
int main(){}
then input to bash:
cd /usr/bin
g++ -g ~/Desktop/a.cpp -o ~/Desktop/a
then the g++ will output plenty of messy code of errors.
I have found the reason is because it don't have authority to link XX.so library.
But if I add a 'sudo' , or set CWD to the path owned by user, g++ will work properly, as follows:
sudo g++ -g ~/Desktop/a.cpp -o ~/Desktop/a
or
cd ~/Desktop
g++ -g ~/Desktop/a.cpp -o ~/Desktop/a
Why do this happen? or how can I fix this?
You don't want to generate code directly in /usr/bin.
You generate your code in your user folder, maybe create a sub-directory called cppwork or something like that.
cd
mkdir cppwork
cd cppwork
g++ -g a.cpp -o a
Once you compiled in your directory, then you copy the file using install which will also take care of stripping the debug if any (i.e. the -g says to keep debug info—stripping is not mandatory).
sudo install -s a /usr/bin/a
As you can see, the place where I use sudo is with the install command.
That being said, I never use those directly. Now a day, I use cmake which means everything works automatically. But that would be a different discussion.
Thanks for every one. I have found the reason. It's because there is an executable program named 'array' in /usr/bin. And when CWD is /usr/bin, the compiler regard this 'array' as the c++ header <array>, so compiling error.
Then I need to find out why the compiler includes /usr/bin by mistake.
I have a fresh install of OS X 10.11.4 that I immediately installed the Xcode toolchain on, then Homebrew, then Boost 1.60. In order to test that everything had gone well, I wrote the following code on my Desktop.
#include <iostream>
#include <boost/filesystem.hpp>
int main() {
boost::filesystem::path new_directory("hello");
boost::filesystem::create_directory(new_directory);
}
I then attempted to compile it as I usually have done with the following command.
$ clang++ test.cpp -o test -lboost_system -lboost_filesystem
I received the following error.
test.cpp:3:10: fatal error: 'boost/filesystem.hpp' file not found
#include <boost/filesystem.hpp>
This is how I have always compiled projects that link Boost in the past. I'm assuming that I have probably forgotten a step along the way that allows clang to search a specific path to dynamically link the libraries. What should I change in order for this compilation command to work?
For me, boost has been compiled and installed into a subdirectory of my home directory, so you'll need to modify the paths as appropriate for your homebrew installation:
flags="-std=c++1z -I/${HOME}/local/include -L${HOME}/local/lib -lboost_filesystem -lboost_system"
c++ ${flags} -o jared jared.cpp
First get the location of boost by doing the following:
brew info boost
From the image above, you can see that my location is
/usr/local/Cellar/boost/1.66.0
Then, to compile, use the following:
c++ -I /usr/local/Cellar/boost/1.66.0 main.cpp -o boost
I wanted to use latest g++ compiler(4.9.1) on suse linux, but suse only supports an older g++ version. So, I took a latest source code from one of the gnu mirror sites and compiled it myself. Everything went fine. But when I tried to compile my test code using the built g++, the compilation fails with error,
"/root/home/include/c++/4.9.1/x86_64-unknown-linux-gnu/bits/os_defines.h:39:22: fatal error: features.h: No such file or directory".
I can find a "features.h" in "/root/home/include/c++/4.9.1/parallel", but I feel that it should be there in "/root/home/include/c++/4.9.1/" itself.
I copied "/root/home/include/c++/4.9.1/parallel/features.h" to "/root/home/include/c++/4.9.1/" just to see what happens. Now it complains with error "whcar.h" not found.
Have I missed something.
Here are the steps I followed to build g++.
1. /root/home/gcc_build/objdir# ../gcc-4.9.1/configure --prefix=/root/home/ --disable-multilib
2. /root/home/gcc_build/objdir# make -j16
3. /root/home/gcc_build/objdir# make install
4. /root/home/gcc_build/test# /root/home/bin/g++ --sysroot /root/home -m64 test.cpp
I resolved the issue by removing sysroot option and pointing c++ include and library path to my home directory. One thing I noticed was that the g++ source does not come with libc and c header files, and libc has to be installed seperately. But with sysroot option, g++ was trying to look all the header files in my home directory.
Below is the command I used to successfully compile the code.
/root/home/bin/g++ -I /root/home/include/c++/4.9.1 -L /root/home/lib64 -Wl,--rpath=/root/home/lib64 --std=c++0x -m64 test.cpp
Take a look at the GCC Directory Options. It is important to use the correct "specifier" as well (-isystem, -L, -B, -I etc)