I've been working on a couple established C++ projects that use static variables from a shared library to store parameters. When compiled with g++ or clang++, the static variable is shared (has the same memory location) throughout the entire program. However, when compiled with Xcode, the main function static variable has a different memory location than the shared library static variable. Is there a way to get Xcode to compile/run the code the same as g++ or clang++, while still being able to debug with Xcode?
Please see example below:
main.cpp:
#include <iostream>
#include "Params.hpp"
int main(int argc, const char * argv[]) {
Params param = Params();
param.addParams();
std::vector<int> vi = Params::ParamsObj();
vi.push_back(10);
for(std::vector<int>::iterator it = vi.begin(); it != vi.end(); ++it) {
std::cout << "i = " << *it << std::endl;
}
return 0;
}
Params.hpp:
#ifndef Params_hpp
#define Params_hpp
#include <vector>
class Params{
typedef std::vector<int> ParamVector;
public:
static ParamVector& ParamsObj() {
static ParamVector m;
return m;
}
void addParams();
};
#endif /* Params_hpp */
Params.cpp:
#include "Params.hpp"
void Params::addParams(){
Params::ParamsObj().push_back(5);
}
Makefile:
clang:
clang++ -dynamiclib Params.cpp -o libshared_clang.dylib
clang++ main.cpp -o main_clang ./libshared_clang.dylib
gpp:
g++-mp-4.9 -Wall -shared -fPIC -o libshared_gpp.so Params.cpp
g++-mp-4.9 -Wall -o main_gpp main.cpp ./libshared_gpp.so
Output from both g++ and clang++ is:
i = 5
i = 10
While Xcode only outputs i = 10.
If I don't use a shared library and compile everything into one binary, Xcode will properly output both print statements.
My current solution is to add the project's main function into its own shared library and then create an Xcode specific file which merely calls the main function in the newly created shared library. However, I was hoping for a solution that didn't require changing the underlying project's code.
