main.cpp
#include <iostream>
#include "Burrito.h"
using namespace std;
int main(){
Burrito b;
return 0;
}
Burrito.h
#ifndef BURRITO_H
#define BURRITO_H
class Burrito{
public:
Burrito();
};
#endif
Burrito.cpp
#include "Burrito.h"
#include <iostream>
Burrito::Burrito(){
}
Compile & Link :
lzsb$ g++ main.cpp -o main
Undefined symbols for architecture x86_64:
"Burrito::Burrito()", referenced from:
_main in ccVpCr0z.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
lzsb$
Platform:
Mac OS 10.6.8
G++ : i686-apple-darwin10 --with-gxx-include-dir=/usr/include/c++/4.2.1
You need to compile the Burrito.cpp file as well. The compiler creates object files from each .cpp file and links them afterwards. This is where your call fails, because the linker can't find the referenced Burrito class in any of your object files. To fix your compiler call just add Burrito.cpp
g++ main.cpp Burrito.cpp -o main
Your compile line should be:
g++ Burrito.cpp main.cpp -o main
Related
I am new to C++. I have a problem with including the header.
I'm trying to compile my a.cpp file and get this error. I'm using Sublime Text as a text editor. Can anyone help me with this problem? Thank you in advance!
Undefined symbols for architecture arm64:
"print()", referenced from:
_main in a-3ccfb2.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Here are my file:
/* Filename: a.cpp */
#include <iostream>
#include "b.h"
using namespace std;
int main() {
print();
return 0;
}
/* Filename: b.h */
#ifndef _b_h
#define _b_h
void print();
#endif
/* Filename: b.cpp */
#include <iostream>
#include "b.h"
using namespace std;
void print() {
cout << "Hello, world!" << endl;
}
I compile my cpp with: (this works fine except when I try to include my header file - example: #include "b.h")
g++ -std=c++17 -Wall a.cpp -o a
g++ --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 13.0.0 (clang-1300.0.29.30)
Target: arm64-apple-darwin21.2.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
I am trying dynamic-linking test.
mylib.cpp
#include<iostream>
#include<stdio.h>
using namespace std;
int hello(){
cout<<"Hello,World!"<<endl;
return 1;
}
then compile
g++ -shared -o libmylib.so mylib.cpp
Now there appears the libmylib.so
test.cpp
#include <iostream>
int hello();
int main() {
hello();
std::cout << "Test Finish!\n";
return 0;
}
Try to compile with this,
g++ -o test test.cpp -L ./
There comes the error
Undefined symbols for architecture x86_64:
"hello()", referenced from:
_main in test-37bd2a.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Do I need to add some options or are there something wrong in my source code??
Thank you for your help.
Do I need to add some options
yes, link with the library.
g++ ... -lmylib
I'm trying to do a test of basic linking for cpp files, I've been searching all over and am having a lot of trouble trying to find a solution. I understand that I have to include the header in both cpp's, but I'm having trouble trying to run these two together.
//testMain.cpp
#include <iostream>
#include <stdio.h>
#include "func.h"
using namespace Temp;
int main()
{
getInfo();
return 0;
}
//func.h
#ifndef FUNC_H
#define FUNC_H
#include <iostream>
#include <stdio.h>
namespace Temp{
int getInfo();
}
#endif
//functions.cpp
#include "func.h"
using namespace std;
int Temp::getInfo()
{
return 5 + 6;
}
//error that I'm getting using VS Code
cd "/Users/jcbwlsn/Downloads/Coding/CPP/Workspace/RPG Project/src/" && g++ testMain.cpp -o testMain && "/Users/jcbwlsn/Downloads/Coding/CPP/Workspace/RPG Project/src/"testMain
Undefined symbols for architecture x86_64:
"Temp::getInfo()", referenced from:
_main in testMain-1f71a1.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
You're supposed to specify all translation unit files when linking a C++ program.
Your program consists of two source files, testMain.cpp and functions.cpp.
Hence the compile-and-link command should be something like:
g++ testMain.cpp functions.cpp -o testMain
Alternatively you can compile each source into separately and then link them into an executable:
g++ -c testMain.cpp -o testMain.o
g++ -c functions.cpp -o functions.o
g++ testMain.o functions.o -o testMain
Having some kind of a Makefile helps to automate this.
I'm new in cpp and when I compile two cpp files in terminal and shows the error as followed
Undefined symbols for architecture x86_64:
"func(int)", referenced from:
_main in main-45889e.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
here are my codes:
main.cpp
#include <stdio.h>
#include <iostream>
#include "func.hpp"
int main(int argc, char* args[]){
func(1);
return 0;
}
func.cpp
#include "func.hpp"
#include <iostream>
int func(int a){
std::cout<<a<<std::endl;
}
func.hpp
int func(int a);
it succeed when I use Xcode to run the code while failed when using terminal to compile with the following g++ commands:
g++ -c main.cpp
g++ -c func.cpp
g++ main.o func.o -o main.out
Please help
I created a simple class 'Hello' in C++ using header(.h) and definition(.cpp) files. This is the header file content:
#ifndef HELLO_H
#define HELLO_H
#include <string>
namespace test
{
class Hello
{
private:
std::string name;
public:
Hello();
void say_hello();
};
}
#endif
And the definition file content is just as you expected:
#include "Hello.h"
#include <iostream.h>
using namespace test;
Hello::Hello()
{
this->name = "Yoppy Yunhasnawa";
}
void Hello::say_hello()
{
string message = "Hello, " + this->name + ".. Have nice day!";
cout << message << "\n";
}
I included this class to a main.cpp file and use it like this:
#include "Hello.h"
using namespace test;
int main(int argc, char *argv[])
{
Hello* hello = new Hello;
hello->say_hello();
}
When I compiled the main.cpp file with g++ like this,
g++ main.cpp
I got following annoying error:
Undefined symbols for architecture x86_64:
"test::Hello::say_hello()", referenced from:
_main in ccsaoOZa.o
"test::Hello::Hello()", referenced from:
_main in ccsaoOZa.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
However, that error does not appear when I don't call both constructor and say_hello method:
int main(int argc, char *argv[])
{
Hello* hello;// = new Hello;
//hello->say_hello();
}
I use macport GCC 4.7 and I am very sure that my method is there but why this symbol(s) not found error keep appearing? Please show me my mistake. Thank you.
When you invoke g++ main.cpp, compiler performs both compiling AND linking. But the code cannot be linked without Hello.cpp file. So, you have two options: either compile and link separately:
g++ -c main.cpp
g++ -c hello.cpp
gcc main.o hello.o
or compile and link everything at the same time:
g++ main.cpp hello.cpp