/* Where a C program keeps its things. Build with -g -O0 and read the addresses.
 *
 * Every address printed here changes between runs, so read the pattern rather
 * than the numbers: which addresses sit near each other, and which one belongs
 * to the pointer instead of the text.
 */
#include <stdio.h>

int counter = 7;                  /* file scope, alive for the whole run */
static int calls;                 /* file scope, and invisible outside this file */
const char *label = "switchback"; /* the pointer is data; the text is read-only */

static void show(const char *what, const void *where) { printf("%-24s %p\n", what, where); }

static int add_one(int n) {
    int local = n + 1; /* automatic: gone when this call returns */

    calls = calls + 1;
    printf("  inside add_one: local=%d at %p, calls=%d at %p\n", local, (void *)&local, calls,
           (void *)&calls);
    return local;
}

int main(void) {
    int here = 41;
    int row[4] = {1, 2, 3, 4};
    char word[] = "quiet";         /* your own cells, filled at run time */
    const char *literal = "quiet"; /* the pointer, not the letters */
    int got;

    show("global counter", (const void *)&counter);
    show("static calls", (const void *)&calls);
    show("pointer label", (const void *)&label);
    show("text label points at", label);
    show("local here", (const void *)&here);
    show("local row", row);
    show("local word", word);
    show("pointer literal", (const void *)&literal);
    show("text literal points at", literal);

    got = add_one(here);
    printf("\nadd_one(%d) returned %d, calls is now %d\n", here, got, calls);
    return 0;
}