framework/src/main/java/org/checkerframework/framework/type/treeannotator/TreeAnnotator.java

package org.checkerframework.framework.type.treeannotator;

import com.sun.source.tree.BinaryTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.Tree;
import com.sun.source.util.SimpleTreeVisitor;
import org.checkerframework.framework.type.AnnotatedTypeFactory;
import org.checkerframework.framework.type.AnnotatedTypeMirror;

/**
 * {@link TreeAnnotator} is an abstract SimpleTreeVisitor to be used with {@link ListTreeAnnotator}.
 *
 * <p>This class does not visit component parts of the tree. By default, the visit methods all call
 * {@link #defaultAction(Tree, Object)}, which does nothing unless overriden. Therefore, subclass do
 * not need to call super unless they override {@link #defaultAction(Tree, Object)}.
 *
 * @see ListTreeAnnotator
 * @see PropagationTreeAnnotator
 * @see LiteralTreeAnnotator
 */
public abstract class TreeAnnotator extends SimpleTreeVisitor<Void, AnnotatedTypeMirror> {

  protected final AnnotatedTypeFactory atypeFactory;

  protected TreeAnnotator(AnnotatedTypeFactory atypeFactory) {
    this.atypeFactory = atypeFactory;
  }

  /**
   * This method is not called when checking a method invocation against its declaration. So,
   * instead of overriding this method, override TypeAnnotator.visitExecutable.
   * TypeAnnotator.visitExecutable is called both when checking method declarations and method
   * invocations.
   *
   * @see org.checkerframework.framework.type.typeannotator.TypeAnnotator
   */
  @Override
  public Void visitMethod(MethodTree node, AnnotatedTypeMirror p) {
    return super.visitMethod(node, p);
  }

  /**
   * When overriding this method, getAnnotatedType on the left and right operands should only be
   * called when absolutely necessary. Otherwise, the checker will be very slow on heavily nested
   * binary trees. (For example, a + b + c + d + e + f + g + h.)
   *
   * <p>If a checker's performance is still too slow, the types of binary trees could be computed in
   * a subclass of {@link org.checkerframework.framework.flow.CFTransfer}. When computing the types
   * in a transfer, look up the value in the store rather than the AnnotatedTypeFactory. Then this
   * method should annotate binary trees with top so that the type applied in the transfer is always
   * a subtype of the type the AnnotatedTypeFactory computes.
   */
  @Override
  public Void visitBinary(BinaryTree node, AnnotatedTypeMirror mirror) {
    return super.visitBinary(node, mirror);
  }
}