A Simple Pointer Language

The language consists of

• Elementary data types (integers and reals) requiring one word each
• Array of these types
• Pointer is used as cursor to run through an array
• Pointer p points to an element of an array
• Variables that could be used as pointers are those declared to be pointers and temporaries that received a value that is pointer plus or minus a constant
• If there is a statement s: p:=&a then after s, p points to a
• If there is a statement s: p:= q ± c where c is an integer, and p and q are pointers then after s, p points to an array that q could point to before s
• If there is a statement s: p:=q then after s, p points to whatever q could point to before s
• In[B] is a set of pairs (p,a) where p is a pointer and a is a variable
• Out[B] is defined in a similar manner for set of values after a block B

Transfer Function

• If s is p : =
  
  

• If s is p:
  
  Array variable}
• If s is p: = q then
  
  
• If s assign to pointer p any other expression then
  
• If s is not an assignment to a pointer then