GCC how to block system calls within a program?

Question

Does anyone tell me how to block some specific system calls within a program, please? I am building a system which takes a piece of C source code, compiles it with gcc and runs

Answer 1

Just to illustrate that this is not possible, the following program:

int main() {
    return 0;
}

makes over 20 system calls as reported using strace. The calls include open (twice) which is one of the calls you seem to want to block.