XCode C++ Ignoring Main Function - c++

I have most bizarre and probably simple to solve problem but it's driving me crazy.
I'm using XCode 4, I've started with an empty project added a new file main.cpp containing:
#include <iostream>
using namespace std;
int main(int argc, const char * argv[]) {
cout << "Hi There!" << endl;
}
Then I added a target called main and added main.cpp to it's sources and compiled and run to be greeted with:
Hello, World!
In return.
Why is XCode adding and compiling it's own main function and how to I tell it to use mine?
It also compiles and runs successfully with an empty main.cpp.
Thanks.

First try cleaning and rebuilding.
If that doesn't work sounds like there is another file with a main in it that is being included in the build.
In the Project File, go into the "Build Phases" tab, and see what is listed under "Compile Sources". The source of your problem might be there.

Related

libclang not finding headers in <> brackets on Mac with Xcode

Edit:
This program compiles. It's only when run does it fail to find iostream. I'm using the libclang.dylib that is bundled with Xcode.
I've written a small tool to begin working with libclang. I'm trying to parse TranslationUnits. The following program is saved in the file tool.cpp. Once compiled and run, it tries to parse tool.cpp as a TU. It's failing to get a clean run with default headers as it cannot find iostream on my Mac. After several attempts to supply arguments that point to the file, it still doesn't work. Any ideas?
#include "tool.h"
#include <iostream>
int main(int argc, char* argv[]) {
CXIndex index = clang_createIndex(0,0);
const char *args[] = {
"-I/usr/include",
"-I/usr/local/include",
"-I.",
"-I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include",
//Should be here
"-I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1"
}
;
Output:
tool.cpp 6:10: 'iostream' file not found
I've got the same issue. I am trying to add CPP to iOS Objective-C. It's not working. I found that this is about next "pain" from Apple because they do not use standard C++ library anymore. I've tried everything that mentioned on this site but haven't found any solution:

Program doesn't start when linking boost filesystem

I'm trying to run a helloworld program which uses boost filesystem.
I'm on Windows with MinGW 8.1 and boost 1.70.
The problem is that, although everything compiles, the program doesn't run. I mean, it runs but doesn't print anything, which means the main function is not even executed:
#include <boost/filesystem.hpp>
#include <iostream>
using namespace std;
using namespace std::string_literals;
namespace fs = boost::filesystem;
int main()
{
cout << "Hello Boost!" << endl;
fs::path abHome{"C:/Users/Me"s};
fs::path jsonFile = abHome / "jsonFile.json"s;
if (!fs::exists(jsonFile)) {
cout << "Creating json file from scratch." << endl;
}
}
"Hello Boost" isn't ever printed to the console.
I've compiled with both CMake and g++ from command line to try to better understand what's going on:
g++ main.cpp -o main -L"C:/Code/boost_1_70_0/stage/lib" -lboost_filesystem-mgw81-mt-x64-1_70 -lboost_system-mgw81-mt-x64-1_70 -I"C:/Code/boost_1_70_0"
I've compiled boost for MinGW by following the guide and everything went well, in the output folder I see many different versions of each library based on the default targets (I haven't really picked them, just went with the defaults).
How can I debug the launch of main.exe to see what's causing the crash? It's been many years since I wrote C++ so I need help to get back on track! :)
The problem was, as #kenba pointed out, that the dynamic linking of the boost dlls was failing.
I erroneously thought I had linked the static version of the boost libraries.
To actually achieve that I should have used this command:
g++ main.cpp -o main -L"C:/Code/boost_1_70_0/stage/lib" -l:"libboost_filesystem-mgw81-mt-x64-1_70.a" -l:"libboost_system-mgw81-mt-x64-1_70.a" -I"C:/Code/boost_1_70_0"
instead of the one I posted in the OP.

Eclipse can't find source file for debugging

Trying to debug simple c++ project that was checkout like new project from Eclipse IDE and was created like "Makefile Project with existing code" by wizard later.
I placed breakpoints and started debugger. Got error:
No source available for "main() at 0x400c6c"
How to make Eclipse to see source?
UPD
Adding source code:
a.cpp
#include <stdio.h>
int main( int argc, char ** argv )
{
printf( "hello world" );
}
makefile
all:a
a.o:a.cpp
gcc -c a.cpp
Looks like problem in "non Eclipse style" makefile. What is the best way to fix such imported non eclipse project?

Using Qt to configure OpenCV library failed

I'm new to Qt creator. Yesterday, I followed the official instructions to configure OpenCV library but it failed. I tried everything on the Internet but it just didn't work. Detailed are listed as belows:
test code is simple, I only want to ensure whether the library works:
#include <iostream>
#include <opencv2/opencv.hpp>
using namespace std;
int main(int argc, char *argv[])
{
cout << "Hello World!" << endl;
return 0;
}
My project configuration is like below :
I thought there might be a problem in debugger. I configure the debugger and I'm quite sure it's ok. The picture is here:
But it just doesn't work. When I click build and run, it says:
C1083: cannot open containing files: "opencv2/opencv.hpp": No such
file or directory.
What's strange is when I include <files> in the editor, the automatic code completion can detect the existence of the OpenCV library and hint after <opencv2/> that there are opencv.hpp, core.hpp .etc. and in the Include Hierarchy, the opencv.hpp exists.
So what might be the problem?

Normal C++ code in Qt doesnt build and run

I am using Qt under linux, if it matters.
I ran successfully under Geany (a simple c++ compiler) the following:
//my first program in C++ Hello World!
#include <iostream>
using namespace std;
int main ()
{cout << "Hello World!";
return 0;}
I opened Qt source file and copied the exact same code and i can't build or run.
Thank you for your responses to this simple problem.
If you did what I think you did, you didn't open this as a project, which is the only place where you can build and run (I think).
Try the following.
- Open Qt Creator.
- Go to File->New File or Project
- At the bottom, select "Qt4 Console Application"
- Select a location; it might be nice to create a folder called "hello_world" or something to store the project in.
- A new project will have been created. Copy over the main.cpp file in sources with your code. My code looked like this:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World!\n";
return 0;
}
Hit "Build All"
Hit "Run"
This worked for me. Hope this helps!