I have been writing c++ for a little while using Visual Studio on Windows, and I recently switched to Linux Mint, and installed Codeblocks to use as my C++ IDE. I have written a very simple program, which I cannot get to compile:
#include <iostream>
int main()
{
std::cout << "Hello world!" << endl;
std::cin.get();
return 0;
}
I have tried running this, and I get a console error message:
Executing: xterm -T Test -e /usr/bin/cb_console_runner LD_LIBRARY_PATH=$LD_LIBRARY_PATH:. /home/***/workspaces/cpp-workspace/Test/bin/Debug/Test (in /home/***/workspaces/cpp-workspace/Test/.)
Process terminated with status -1 (0 minute(s), 0 second(s))
I have also tried running cc against my main.cpp file, and I get an error message saying:
/tmp/cc4RcEeE.o: In function `main':
main.cpp:(.text+0xe): undefined reference to `std::cout'
main.cpp:(.text+0x13): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
main.cpp:(.text+0x1d): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
main.cpp:(.text+0x28): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
main.cpp:(.text+0x2f): undefined reference to `std::cin'
main.cpp:(.text+0x34): undefined reference to `std::istream::get()'
/tmp/cc4RcEeE.o: In function `__static_initialization_and_destruction_0(int, int)':
main.cpp:(.text+0x64): undefined reference to `std::ios_base::Init::Init()'
main.cpp:(.text+0x79): undefined reference to `std::ios_base::Init::~Init()'
collect2: error: ld returned 1 exit status
Additional Information:
I have installed GCC on my machine
I installed Codeblocks using the Mint Software Manager
I have been researching this problem over the course of a week or so, and have been unable to get anything to work. Any help getting this compile would be much appreciated!
EDIT
I have checked through my compiler settings according to the suggestions given, and they all appear correct. I've added a screenshot of my settings in case someone sees something... Also, g++ is not listed as an option in the drop-down for compilers.
My codeblocks settings
cc builds C programs. That won't bring in the standard library for C++, hence the linker errors.
You want a C++ compiler, like the one you have already installed: g++.
Indeed, until you've built your program successfully, you won't be able to execute it.
This ought to be covered in your C++ book, which you can review now.
Related
I'm trying to compile c++ in Sublime text. I've managed to install the the relevant packages for the MinGw on my computer. As well as creating a path file in the System environment variables under the directory C:\MinGW\bin, its exact location. And subsequently generated a new build system in the editor, containg the fallowing:
{
"cmd" : "gcc $file_name -o ${file_base_name} && ${file_base_name}",
"selector" : "source.c",
"shell": true,
"working_dir" : "$file_path"
}
I went further to check in cmd if my installation of the compiler was done properly, and it was.
>gcc --version
gcc (MinGW.org GCC Build-2) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
I typed in sublime this code:
#include<iostream>
using namespace std;
int main(){
cout<<"hello world";
}
The compiled result was this :
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Users\44750\AppData\Local\Temp\ccVYP6T2.o:item.cpp:(.text+0x19): undefined reference to `std::cout'
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Users\44750\AppData\Local\Temp\ccVYP6T2.o:item.cpp:(.text+0x1e): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Users\44750\AppData\Local\Temp\ccVYP6T2.o:item.cpp:(.text+0x35): undefined reference to `std::ios_base::Init::~Init()'
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Users\44750\AppData\Local\Temp\ccVYP6T2.o:item.cpp:(.text+0x56): undefined reference to `std::ios_base::Init::Init()'
collect2.exe: error: ld returned 1 exit status
[Finished in 0.8s]
You set gcc as the compiler, but you are building c++.
Building with gcc may allow it to compile the C++, but it will not automatically link in the required standard library -- which results in the failed link errors that you are experiencing.
Either change the cmd to use g++, or add the flag "-x c++" so that it knows that this is C++ code, which should allow it to pull in the correct libraries.
I have written a C++ file in nano text editor (UNIX command line) and I am trying to execute it with this command: c++ main.cpp. When I run it, no error messages display, however, there's also no successful messages; simply nothing appears... I also tried clang which gave me some more details, click here to view the error message.
My code:
#include <iostream>
using namespace std;
int main() {
cout << "Hello" << endl;
return 0;
}
Clang Output:
/usr/bin/ld: /tmp/main-ad7332.o: in function `main':
main.cpp:(.text+0x11): undefined reference to `std::cout'
/usr/bin/ld: main.cpp:(.text+0x24): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
/usr/bin/ld: main.cpp:(.text+0x2d): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
/usr/bin/ld: main.cpp:(.text+0x36): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
/usr/bin/ld: /tmp/main-ad7332.o: in function `__cxx_global_var_init':
main.cpp:(.text.startup+0x13): undefined reference to `std::ios_base::Init::Init()'
/usr/bin/ld: main.cpp:(.text.startup+0x19): undefined reference to `std::ios_base::Init::~Init()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
No output whatsoever is the expected outcome. Running c++ only compiles the provided source file. To run your program, you will have to explicitly run the produced executable, which by default is a.out.
With regards to the error messages you received from clang, make sure that you are using clang++ and remembered to include the iostream header, which declares std::cout.
This question already has answers here:
Linking Fortran and C++ binaries using gcc
(1 answer)
gfortran undefined references
(1 answer)
Undefined reference to `std::chrono::_V2::system_clock::now()' when linking with gfortran
(1 answer)
Closed 3 years ago.
Recently, I was working on a project where some C++ subroutines are called by Fortran scripts (A Fortran solver intends to have some data-post-processing capability which is from a lib developed in C++). The following procedures replay the error producing process. Here I use quite simple Fortran and C++ scripts for a easy and clear demonstration.
A simple Fortran main program calls a CXX subroutine:
The CXX subroutine - sub1.cxx:
#include <stdio.h>
using namespace :: std;
extern "C" void func_c_();
void func_c_()
{
printf("%d\n", 100);
}
The Fortran main program - sub2.f90:
program func_fortran
implicit none
call func_c()
end program func_fortran
Compile them:
g++ -c sub1.cxx
gfortran -o test sub2.f90 sub1.o
We get the executable - test. Up to now, there is no problem.
Then we replace the sub1.cxx by sub1.1.cxx. It looks like:
#include <iostream>
using namespace :: std;
extern "C" void func_c_();
void func_c_()
{
cout << "I am a CXX." << endl;
}
The Fortran main program is totally the same with the previous one. We did not touch it.
Now we compile the codes:
g++ -c sub1.1.cxx
gfortran -o test sub2.f90 sub1.1.o
We can obtain sub1.1.o. But the error messages are thrown out:
sub1.1.o: In function `func_c_':
sub1.1.cxx:(.text+0xa): undefined reference to `std::cout'
sub1.1.cxx:(.text+0xf): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
sub1.1.cxx:(.text+0x14): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
sub1.1.cxx:(.text+0x1c): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
sub1.1.o: In function `__static_initialization_and_destruction_0(int, int)':
sub1.1.cxx:(.text+0x46): undefined reference to `std::ios_base::Init::Init()'
sub1.1.cxx:(.text+0x55): undefined reference to `std::ios_base::Init::~Init()'
collect2: error: ld returned 1 exit status
Compared with sub1.cxx, it seems some C++ standards in sub1.1.cxx e.g. std::cout can not be recognized. Any one could figure this problem out?
Additionally, here I did not use the iso_c_binding from Fortran 2013. I tried this features in some other cases but it does not work either.
You need to link the executable against the c++ standard library:
g++ -c sub1.1.cxx
gfortran -o test sub2.f90 sub1.1.o -lstdc++
With gfortran/g++ you can also use g++ to link against the fortran library:
g++ -c sub1.1.cxx
gfortran -c sub2.f90
g++ -o test sub1.o sub2.o -lgfortran
okay this I did accidentally , compiling .cpp using gcc and not g++
but I actually want to understand the console output, line by line, if it has any sense.
struct a{
int pointer;
int rollno;
};
struct a student,*studentref;
studentref = &student;
studentref->rollno = 141;
studentref->pointer = 8;
cout<<studentref->rollno<<") : "<<studentref->pointer<<endl;
compiling this code with gcc structpointers.cpp -o structp gives the following output:
sourab#sourab:/home/gbear/coding/learningds$ gcc structpointers.cpp -o structp
/tmp/ccXrq1Cv.o: In function `main':
structpointers.cpp:(.text+0x2e): undefined reference to `std::cout'
structpointers.cpp:(.text+0x33): undefined reference to `std::ostream::operator<<(int)'
structpointers.cpp:(.text+0x38): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
structpointers.cpp:(.text+0x40): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
/tmp/ccXrq1Cv.o: In function `__static_initialization_and_destruction_0(int, int)':
structpointers.cpp:(.text+0x6e): undefined reference to `std::ios_base::Init::Init()'
structpointers.cpp:(.text+0x7d): undefined reference to `std::ios_base::Init::~Init()'
collect2: error: ld returned 1 exit status
The most egregious difference between calling g++ and gcc on a .cpp file is that g++ automatically links in the C++ standard library, while gcc does not; all the errors you see are linker errors of missing references to stuff that is provided by the C++ standard library.
(notice that this isn't the only difference; see this question for details)
g++ and gcc are compiler drivers of GNU compiler collection, they have backends which are connected automatically once compilation mode in up.
The errors like "
structpointers.cpp:(.text+0x2e): undefined reference to `std::cout'
are link errors,since you have used gcc to compile cpp,the standard libraries specifically for cpp are not present, so it could not find syntax like std::cout etc.
you can also refer to : compiling with g++
I having trouble configuring distcc to compile C++ files. I did a standard small "Hello, World" program in C++ and am trying to get distcc to compile it locally (before I get fancy with a larger project), but I am getting "undefined reference" errors.
My program, called "hello.cpp":
#include <iostream>
int main(){
std::cout << "Hello World in c++" << std::endl;
return 0;
}
My command:
$ distcc hello.cpp
Terminal output:
/tmp/cc5rZwhV.o: In function `main': <br>
hello.cpp:(.text+0xa): undefined reference to `std::cout' <br>
hello.cpp:(.text+0xf): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)' <br>
hello.cpp:(.text+0x14): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)' <br>
hello.cpp:(.text+0x1c): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))' <br>
/tmp/cc5rZwhV.o: In function `__static_initialization_and_destruction_0(int, int)': <br>
hello.cpp:(.text+0x4a): undefined reference to `std::ios_base::Init::Init()' <br>
hello.cpp:(.text+0x59): undefined reference to `std::ios_base::Init::~Init()' <br>
collect2: error: ld returned 1 exit status <br>
distcc[21053] ERROR: compile hello.cpp on localhost failed <br>
Other information:
This program compiles just fine with g++ and C++. A similar program written in C using printf works with distcc.
Output of $ distcc --version:
distcc 3.2rc1 x86_64-unknown-linux-gnu
(protocols 1, 2 and 3) (default port 3632)
built Jul 7 2014 13:18:34
....(copyright stuff)
Add -lstdc++ to your linker command line (that is, add libstdc++ to your linked libraries explicitly, which normally g++ would do for you).
While you're at it, try icecc as well. I personally prefer it.