(C++) declaration of 'std::string fil' shadows a parameter

I am trying to make my own compiler(yes) and c++(cpp version of cc) is giving me an error saying: error: declaration of ‘std::string fil’ shadows a parameter.

Code:

#include <iostream>
#include <cstring>
#include <string>

int compile(std::string fil)
{
    std::string cmd = "cc ", fil; // error here
    system(cmd);
    return 0;
}

int main(int argc, char* argv[])
{
   if (argc == 2) {
       std::string tmp = argv[1];
       compile(tmp);
   }
   return 0;
}

>Solution :

Not Sure what is your question – but compiler is correct:

<source>:7:30: error: redefinition of 'fil'
    std::string cmd = "cc ", fil; // error here
                             ^
<source>:5:25: note: previous definition is here
int compile(std::string fil)

You have a redefinition of parameter. You should rename one of them.

to add strings

    std::string cmd = "cc " + fil; // error here