As part of adding a new pass to GCC I am intercepting addition to and subtraction from pointers. These are represented by PLUS_EXPR and MINUS_EXPR tree nodes. I need to be able to find out which of the node's two operands is the actual pointer and which is the integer that has been added to it.
Subtraction is not a problem. The real pointer always seems to be the first operand (makes sense). If the integer is a constant (e.g. p = p + 4) I can catch it by checking the type: TREE_CODE (TREE_OPERAND (t, 0)) == INTEGER_CST But in other cases (e.g. p = p + i) I can't do this by looking at the type as they both have the same type as the result pointer. Is there another way to find out which is which? Thanks. Alex
