Question

I am doing this programming assignment in C. But I am confused as to how to organize it.

So, here is the situation. I have two tree implementations and declare their struct/includes/function prototypes and so on in two separate header files. Then I have two c source code for the two implementations. Now here comes the problem. I have one test c file (only one main function for running tests) for the ADTs of Trees. Since the two implementations are going to use the same test. How can I avoid making two copies of the same main.c file? when I include the header file of tree implementation1, I can do gcc Tree_implementation1.c main.c. But to do implementation2, I have to got back in the main source file and manually change the include to tree implementation2, and then I can use the same compilation command. How do I work around this to toggle between the two implementations with only one main.c?

Answer 1

Use the preprocessor and a constant that you can set on the command line:

In your main.c:

#ifdef TREE_IMPL1
#include "TreeImplementation1.h"
#else
#include "TreeImplementation2.h"
#endif

// ...

int main(int argc, char **argv)
{
#ifdef TREE_IMPL1
    // code for testing TreeImplementation1
#else
    // code for testing TreeImplementation2
#endif
}

When you compile, pass or omit TREE_IMPL1 on the command line, or set it in your IDE:

gcc -DTREE_IMPL1 main.c ...