public class CodeCleaner extends NodeVisitor
CodeCleaner
runs over the AST and performs some trivial
dead code elimination, while flattening blocks wherever possible.Modifier and Type | Field and Description |
---|---|
protected AlphaRenamer |
alphaRen |
protected NodeFactory |
nf |
Constructor and Description |
---|
CodeCleaner(NodeFactory nf)
Creates a visitor for cleaning code.
|
Modifier and Type | Method and Description |
---|---|
protected java.util.List<Stmt> |
clean(java.util.List<Stmt> l)
Performs some trivial dead code elimination on a list of statements.
|
protected java.util.List<Stmt> |
flattenBlock(Block b)
Turns a Block into a list of Stmts.
|
protected java.util.Set<java.lang.String> |
labelRefs(Block b)
Traverses a Block and determines the set of label references.
|
Node |
leave(Node old,
Node n,
NodeVisitor v)
This method is called after all of the children of
n
have been visited. |
protected NodeFactory nf
protected AlphaRenamer alphaRen
public CodeCleaner(NodeFactory nf)
nf
- The node factory to be used when generating new nodes.public Node leave(Node old, Node n, NodeVisitor v)
NodeVisitor
n
have been visited. In this case, these children were visited by the
visitor v
. This is the last chance for the visitor to
modify the tree rooted at n
. This method will be called
exactly the same number of times as entry
is called.
That is, for each node that is not overridden, enter
and
leave
are each called exactly once.
Note that if old == n
then the visitor should make a copy
of n
before modifying it. It should then return the
modified copy.
This method is typically called by the method
leave(parent, old, n v)
.
If a subclass overrides the method
leave(parent, old, n v)
then this method may not be called.
leave
in class NodeVisitor
old
- The original state of root of the current subtree.n
- The current state of the root of the current subtree.v
- The NodeVisitor
object used to visit the children.n
.protected java.util.List<Stmt> flattenBlock(Block b)
protected java.util.List<Stmt> clean(java.util.List<Stmt> l)
protected java.util.Set<java.lang.String> labelRefs(Block b)