Propagating the Types of Unexamined Variables
Suppose “subroutine” A is
- called from two sites, B and C
- only uses or sets local variables 1 .. 5
Suppose at call site B the type of local variable 6 is float
Suppose at call site C the type of local variable 6 is int
At the entry to A the local variables 6 will be marked as unusable.
At the exit of A and the successor of B and C local variable 6 will be marked as unusable.