| package org.checkerframework.dataflow.cfg.node; |
| |
| /*>>> |
| import org.checkerframework.checker.nullness.qual.Nullable; |
| */ |
| |
| import org.checkerframework.dataflow.cfg.CFGBuilder; |
| import org.checkerframework.dataflow.cfg.block.Block; |
| |
| import java.util.Collection; |
| import java.util.LinkedList; |
| |
| import javax.lang.model.type.TypeMirror; |
| |
| import com.sun.source.tree.Tree; |
| |
| /** |
| * A node in the abstract representation used for Java code inside a basic |
| * block. |
| * |
| * <p> |
| * |
| * The following invariants hold: |
| * |
| * <pre> |
| * block == null || block instanceof RegularBlock || block instanceof ExceptionBlock |
| * block instanceof RegularBlock ==> block.getContents().contains(this) |
| * block instanceof ExceptionBlock ==> block.getNode() == this |
| * block == null <==> "This object represents a parameter of the method." |
| * </pre> |
| * |
| * <pre> |
| * type != null |
| * tree != null ==> node.getType() == InternalUtils.typeOf(node.getTree()) |
| * </pre> |
| * |
| * @author Stefan Heule |
| * |
| */ |
| public abstract class Node { |
| |
| /** |
| * The basic block this node belongs to (see invariant about this field |
| * above). |
| */ |
| protected /*@Nullable*/ Block block; |
| |
| /** |
| * Is this node an l-value? |
| */ |
| protected boolean lvalue = false; |
| |
| /** |
| * The assignment context of this node. See {@link AssignmentContext}. |
| */ |
| protected /*@Nullable*/ AssignmentContext assignmentContext; |
| |
| /** |
| * Does this node represent a tree that appears in the source code (true) |
| * or one that the CFG builder added while desugaring (false). |
| */ |
| protected boolean inSource = true; |
| |
| /** |
| * The type of this node. For {@link Node}s with {@link Tree}s, this type is |
| * the type of the {@link Tree}. Otherwise, it is the type is set by the |
| * {@link CFGBuilder}. |
| */ |
| protected final TypeMirror type; |
| |
| public Node(TypeMirror type) { |
| assert type != null; |
| this.type = type; |
| } |
| |
| /** |
| * @return The basic block this node belongs to (or {@code null} if it |
| * represents the parameter of a method). |
| */ |
| public /*@Nullable*/ Block getBlock() { |
| return block; |
| } |
| |
| /** Set the basic block this node belongs to. */ |
| public void setBlock(Block b) { |
| block = b; |
| } |
| |
| /** |
| * Returns the {@link Tree} in the abstract syntax tree, or |
| * <code>null</code> if no corresponding tree exists. For instance, this is |
| * the case for an {@link ImplicitThisLiteralNode}. |
| * |
| * @return The corresponding {@link Tree} or <code>null</code>. |
| */ |
| abstract public /*@Nullable*/ Tree getTree(); |
| |
| /** |
| * Returns a {@link TypeMirror} representing the type of a {@link Node} A |
| * {@link Node} will always have a type even when it has no {@link Tree}. |
| * |
| * @return A {@link TypeMirror} representing the type of this {@link Node}. |
| */ |
| public TypeMirror getType() { |
| return type; |
| } |
| |
| /** |
| * Accept method of the visitor pattern |
| * |
| * @param <R> |
| * Result type of the operation. |
| * @param <P> |
| * Parameter type. |
| * @param visitor |
| * The visitor to be applied to this node. |
| * @param p |
| * The parameter for this operation. |
| */ |
| public abstract <R, P> R accept(NodeVisitor<R, P> visitor, P p); |
| |
| public boolean isLValue() { |
| return lvalue; |
| } |
| |
| /** |
| * Make this node an l-value. |
| */ |
| public void setLValue() { |
| lvalue = true; |
| } |
| |
| public boolean getInSource() { |
| return inSource; |
| } |
| |
| public void setInSource(boolean inSrc) { |
| inSource = inSrc; |
| } |
| |
| public AssignmentContext getAssignmentContext() { |
| return assignmentContext; |
| } |
| |
| public void setAssignmentContext(AssignmentContext assignmentContext) { |
| this.assignmentContext = assignmentContext; |
| } |
| |
| /** |
| * @return A collection containing all of the operand {@link Node}s of this |
| * {@link Node}. |
| */ |
| public abstract Collection<Node> getOperands(); |
| |
| /** |
| * @return A collection containing all of the operand {@link Node}s of this |
| * {@link Node}, as well as (transitively) the operands of its |
| * operands. |
| */ |
| public Collection<Node> getTransitiveOperands() { |
| LinkedList<Node> operands = new LinkedList<>(getOperands()); |
| LinkedList<Node> transitiveOperands = new LinkedList<>(); |
| while (!operands.isEmpty()) { |
| Node next = operands.removeFirst(); |
| operands.addAll(next.getOperands()); |
| transitiveOperands.add(next); |
| } |
| return transitiveOperands; |
| } |
| |
| } |