Storage Allocation | Compiler Design - Computer Science Engineering (CSE) PDF Download

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The different ways to allocate memory are:

• Static storage allocation
• Stack storage allocation
• Heap storage allocation

Static Storage Allocation

• In static allocation, names are bound to storage locations.
• If memory is created at compile time then the memory will be created in static area and only once.
• Static allocation supports the dynamic data structure that means memory is created only at compile time and deallocated after program completion.
• The drawback with static storage allocation is that the size and position of data objects should be known at compile time.
• Another drawback is restriction of the recursion procedure.

Stack Storage Allocation

• In static storage allocation, storage is organized as a stack.
• An activation record is pushed into the stack when activation begins and it is popped when the activation end.
• Activation record contains the locals so that they are bound to fresh storage in each activation record. The value of locals is deleted when the activation ends.
• It works on the basis of last-in-first-out (LIFO) and this allocation supports the recursion process.

Heap Storage Allocation

• Heap allocation is the most flexible allocation scheme.
• Allocation and deallocation of memory can be done at any time and at any place depending upon the user's requirement.
• Heap allocation is used to allocate memory to the variables dynamically and when the variables are no more used then claim it back.
• Heap storage allocation supports the recursion process.

Example:

fact (int n)  

{  

   if (n<=1)  

       return 1;  

   else   

       return (n * fact(n-1));  

}  

fact (6)

The dynamic allocation is as follows: