Question 5: Data Types and Scopes (25 Marks)

a) Describe the eager approaches to reclaiming garbage (8points)

b) How is a reference to non-local variable in a static-scoped program connected to its definition? (5 points)

c) Consider the following skeletal C program:

void fun1(void); /* prototype */

void fun2(void); /* prototype */

void fun3void); /* prototype */

void main() {

int u, v, w;

. . .

}

void fun1(void) {

int v, w, x;

. . .

}

void fun2(void) {

int w, x, y;

. . .

}

void fun3(void) {

int x, y, z;

. . .

}

what variables are visible during execution of the last function called in the calling sequence:

main calls fun3; fun3 calls fun2; fun2 calls fun1.

assuming that dynamic scoping is used? Include with each visible variable the name of the function in which it was defined. (12 points):