What is an activation record and what are the elements of an activation record?

Activation record is used to manage the information needed by a single execution of a procedure. An activation record is pushed into the stack when a procedure is called and it is popped when the control returns to the caller function.

What is activation record in compiler design?

An activation record contains all the necessary information required to call a procedure. An activation record may contain the following units (depending upon the source language used). Temporaries. Stores temporary and intermediate values of an expression.

What is activation record explain the general structure of activation record?

A general activation record consist of the following things: Local variables: hold the data that is local to the execution of the procedure. Temporary values: stores the values that arise in the evaluation of an expression. Machine status: holds the information about status of machine just before the function call.

What is in an activation record?

An activation record (AR) is a private block of memory associated with an invocation of a procedure. It is a runtime structure used to manage a procedure call. An AR is used to map a set of arguments, or parameters, from the caller’s name space to the callee’s name space.

Where is the activation record stored in the compiler?

An activation record contains all the necessary information required to call a procedure. An activation record may contain the following units (depending upon the source language used). Whenever a procedure is executed, its activation record is stored on the stack, also known as control stack.

Which is an example of an activation record?

Example Step 1: h(4)called Chunk of memory allocated on the stack in order to hold local variables of h. The activation record (or stack frame) of h is pushed onto the stack. Stack Frame for h y=4 Step 2: g(4)called Activation record for g allocated (pushed) on stack. Stack Frame for h y=4 Stack Frame for g x=4 y=10

How are activation trees used in compiler design?

If ‘a’ and ‘b’ be two procedures then their activations will be non-overlapping (when one is called after other) or nested (nested procedures). A procedure is recursive if a new activation begins before an earlier activation of the same procedure has ended. An activation tree shows the way control enters and leaves activations.

How are activation records allocated in a language?

In a language with recursion, each simultaneous activation of a recursive subprogram can have different parameters, different values for local variables, return a different result. Allocation of activation records is dynamic, and local variables are stack dynamic (unless declared static).