Stack size dimension ocupied by recursive function

Question

For a C++ program that is using a recursive function, how can I evaluate the dynamic stack size occupied by this function?

Answer 1

void recursive_function()
{
  int dummy;
  cout << "stack = " << &dummy << '\n';
  ...
}

Watch the value of &dummy rise as the stack usage goes up (or fall if your stack grows downwards).

Answer 2

#include <stdio.h>
#include <stdlib.h>

ssize_t recurse(int limit, char* stack = NULL)
{
    char dummy;

    if (stack == NULL)
        stack = &dummy;

    if (limit > 0)
        return recurse(limit - 1, stack);
    else
        return stack - &dummy;
}

int main(int argc, char* argv[])
{
    int limit = atoi(argv[1]);
    printf("depth %d took %zd bytes\n", limit, recurse(limit));
    return EXIT_SUCCESS;
}

If I run this with 4 I get:

depth 4 took 192 bytes

As others have suggested in comments, this is not completely portable, but it should work on a fairly wide variety of current systems. Note that the result type is signed in case something "weird" happens--you can surely check it for sanity (say, make sure it's between 5 and 500, depending on what else your function contains).