All GENERIC trees have two fields in common. First,
is a pointer that can be used as a singly-linked list to other trees.
The other is
TREE_TYPE. Many trees store the type of an
expression or declaration in this field.
These are some other functions for handling trees:
Return the number of bytes a tree takes.
These functions build a tree and supply values to put in each
parameter. The basic signature is ‘code, type, [operands]’.
code is the
type is a tree
TREE_TYPE. These are followed by the
operands, each of which is also a tree.