Activation records and call stack in Compiler Design - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an activation record in the context of program execution?

An activation record is a block of memory that stores information about a single execution of a procedure or function. It typically contains the function's parameters, local variables, return address, and control information.

beginner

What role does the call stack play during program execution?

The call stack keeps track of active function calls in a program. Each time a function is called, an activation record is pushed onto the stack. When the function finishes, its activation record is popped off, returning control to the caller.

intermediate

Why is the call stack important for nested or recursive function calls?

The call stack allows the program to remember where to return after each function call, even when functions call other functions or themselves recursively. It keeps each call's data separate and organized.

intermediate

What information is typically stored in an activation record?

An activation record usually stores: function parameters, local variables, return address (where to continue after the function ends), and sometimes saved registers or control links.

advanced

How does the call stack help in error handling like stack overflow?

If too many functions are called without returning (like in infinite recursion), the call stack grows beyond its limit, causing a stack overflow error. This helps detect problems in program flow.

What happens to the activation record when a function finishes execution?

A It remains on the call stack permanently

B It is pushed onto the call stack

C It is copied to another stack

D It is popped off the call stack

When a function finishes, its activation record is removed (popped) from the call stack to return control to the caller.

Which of the following is NOT typically stored in an activation record?

A User interface settings

B Local variables

C Return address

D Function parameters

User interface settings are unrelated to function execution and are not stored in activation records.

Why is the call stack called a 'stack'?

A Because it stores data in a queue order

B Because it stores data in a last-in, first-out order

C Because it stores data randomly

D Because it stores data permanently

The call stack uses last-in, first-out (LIFO) order, meaning the most recent function call is handled first.

What problem can occur if the call stack grows too large?

A Stack overflow

B Syntax error

C Memory leak

D Infinite loop

If the call stack exceeds its size limit, a stack overflow error occurs, often due to deep or infinite recursion.

Which of these best describes the purpose of the return address in an activation record?

A To store the function's local variables

B To save the function's parameters

C To know where to continue after the function ends

D To keep track of the program's memory usage

The return address tells the program where to resume execution after the current function finishes.

Explain what an activation record is and what information it contains.

Think about what a function needs to remember while it runs.

Describe how the call stack manages multiple function calls, including recursive calls.

Imagine stacking plates and removing them in reverse order.