从C中的另一个文件更新静态全局变量

Question

Update static variable outside of the file without modifying the file in which the static variable is declared in C lang.

Proj1 creates dll. Proj1 has abc.h file and it is defined as below :

static BOOl stvar = False;//declared as global static variable

func1()
{
    stvar= TRUE;
}

func2()
{
    if(stvar == TRUE)
    {
        ....
    }
    else
    {
        func1();  //call to func1 sets STVAR = TRUE;
    }
}

Proj2 Creates exe. It has cprog1.c file. cprog1.c file is defined as follows:

cprogfunc1()
{
    func2(); //call to func2 sets STVAR = TRUE;
}

cprogfunc2()
{
    stvar = FALSE;
    func2();
}

We are setting stvar to false in cprogfunc2() to make it execute else block in func2() of abc. h file . But the value we set in cprogfunc2() under cprog1.c is not reflected in abc.h file. We are updating static variable outside its declaration because we cannot modify anything under proj1 . So please suggest some ways to update static variable from cprog1.c file without modifying abc.h/Proj1 . If that is not possible suggest any workaround. Thanks.

Solutions already tried :

1. Making stvar non static - not possible since we can not modify abc.h file
2. Using pointers - did not work

Answer 1

By definition, stvar was made static in order to limit accessibility to it, meaning the ideal way to tinker with it from the outside is to create an API for it (or indeed make it global, not static). Since editing Proj1 is out of the question, we are left with a bad situation.

What you could do is to reset Proj1's state by freeing the dll and loading it again, as mention here.