com.ibm.wala.analysis.reflection.GetMethodContextInterpreter Maven / Gradle / Ivy

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/*
 * Copyright (c) 2013 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 */
package com.ibm.wala.analysis.reflection;

import com.ibm.wala.analysis.reflection.GetMethodContext.NameItem;
import com.ibm.wala.analysis.typeInference.TypeAbstraction;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.cfg.InducedCFG;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.classLoader.NewSiteReference;
import com.ibm.wala.core.util.strings.Atom;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.Context;
import com.ibm.wala.ipa.callgraph.ContextKey;
import com.ibm.wala.ipa.callgraph.propagation.SSAContextInterpreter;
import com.ibm.wala.ipa.summaries.SyntheticIR;
import com.ibm.wala.ssa.ConstantValue;
import com.ibm.wala.ssa.DefUse;
import com.ibm.wala.ssa.IR;
import com.ibm.wala.ssa.IRView;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSAInstructionFactory;
import com.ibm.wala.ssa.SSAOptions;
import com.ibm.wala.ssa.SSAReturnInstruction;
import com.ibm.wala.types.FieldReference;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.util.collections.EmptyIterator;
import com.ibm.wala.util.collections.HashMapFactory;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.collections.NonNullSingletonIterator;
import com.ibm.wala.util.debug.Assertions;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

/**
 * Understands {@link com.ibm.wala.analysis.reflection.GetMethodContext}.
 *
 * @author Michael Heilmann
 * @see com.ibm.wala.analysis.reflection.GetMethodContext
 * @see com.ibm.wala.analysis.reflection.GetMethodContextSelector
 */
public class GetMethodContextInterpreter implements SSAContextInterpreter {
  /** TODO MH: Maybe hard-code those in {@link com.ibm.wala.types.MethodReference}? */
  public static final MethodReference GET_METHOD =
      MethodReference.findOrCreate(
          TypeReference.JavaLangClass,
          "getMethod",
          "(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;");

  /** TODO MH: Maybe hard-code those in {@link com.ibm.wala.types.MethodReference}? */
  public static final MethodReference GET_DECLARED_METHOD =
      MethodReference.findOrCreate(
          TypeReference.JavaLangClass,
          "getDeclaredMethod",
          "(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;");

  private static final boolean DEBUG = false;

  @Override
  public IR getIR(CGNode node) {
    if (node == null) {
      throw new IllegalArgumentException("node is null");
    }
    assert understands(node);
    if (DEBUG) {
      System.err.println("generating IR for " + node);
    }
    IMethod method = node.getMethod();
    Context context = node.getContext();
    Map constants = HashMapFactory.make();
    if (method.getReference().equals(GET_METHOD)) {
      Atom name = Atom.findOrCreateAsciiAtom(((NameItem) context.get(ContextKey.NAME)).name());
      SSAInstruction instrs[] = makeGetMethodStatements(context, constants, name);
      return new SyntheticIR(
          method,
          context,
          new InducedCFG(instrs, method, context),
          instrs,
          SSAOptions.defaultOptions(),
          constants);
    }
    if (method.getReference().equals(GET_DECLARED_METHOD)) {
      Atom name = Atom.findOrCreateAsciiAtom(((NameItem) context.get(ContextKey.NAME)).name());
      SSAInstruction instrs[] = makeGetDeclaredMethodStatements(context, constants, name);
      return new SyntheticIR(
          method,
          context,
          new InducedCFG(instrs, method, context),
          instrs,
          SSAOptions.defaultOptions(),
          constants);
    }
    Assertions.UNREACHABLE("Unexpected method " + node);
    return null;
  }

  @Override
  public IRView getIRView(CGNode node) {
    return getIR(node);
  }

  @Override
  public int getNumberOfStatements(CGNode node) {
    assert understands(node);
    return getIR(node).getInstructions().length;
  }

  @Override
  public boolean understands(CGNode node) {
    if (node == null) {
      throw new IllegalArgumentException("node is null");
    }
    if (!node.getContext().isA(GetMethodContext.class)) {
      return false;
    }
    MethodReference mRef = node.getMethod().getReference();
    return mRef.equals(GET_METHOD) || mRef.equals(GET_DECLARED_METHOD);
  }

  @Override
  public Iterator iterateNewSites(CGNode node) {
    if (node == null) {
      throw new IllegalArgumentException("node is null");
    }
    assert understands(node);
    TypeReference tr =
        ((TypeAbstraction) node.getContext().get(ContextKey.RECEIVER)).getTypeReference();
    if (tr != null) {
      return new NonNullSingletonIterator<>(NewSiteReference.make(0, tr));
    }
    return EmptyIterator.instance();
  }

  @Override
  public Iterator iterateCallSites(CGNode node) {
    assert understands(node);
    return EmptyIterator.instance();
  }

  /**
   * Get all non-constructor, non-class-initializer methods declared by a class if their name is
   * equal to the specified name.
   *
   * @param cls the class
   * @param name the name
   */
  private static Collection getDeclaredNormalMethods(IClass cls, Atom name) {
    Collection result = HashSetFactory.make();
    for (IMethod m : cls.getDeclaredMethods()) {
      if (!m.isInit() && !m.isClinit() && m.getSelector().getName().equals(name)) {
        result.add(m);
      }
    }
    return result;
  }

  /**
   * Get all non-constructor, non-class-initializer methods declared by a class and all its
   * superclasses if their name is equal to the specified name.
   *
   * @param cls the class
   * @param name the name
   */
  private static Collection getAllNormalPublicMethods(IClass cls, Atom name) {
    Collection result = HashSetFactory.make();

    Collection allMethods = cls.getAllMethods();
    for (IMethod m : allMethods) {
      if (!m.isInit() && !m.isClinit() && m.isPublic() && m.getSelector().getName().equals(name)) {
        result.add(m);
      }
    }
    return result;
  }

  /**
   * Create statements for methods like getMethod() and getDeclaredMethod(), which return a single
   * method. This creates a return statement for each possible return value, each of which is a
   * {@link ConstantValue} for an {@link IMethod}.
   *
   * @param returnValues the possible return values for this method
   * @return the statements
   */
  private static SSAInstruction[] getParticularMethodStatements(
      MethodReference ref,
      Collection returnValues,
      Context context,
      Map constants) {
    ArrayList statements = new ArrayList<>();
    int nextLocal = ref.getNumberOfParameters() + 2;
    IClass cls = ((TypeAbstraction) context.get(ContextKey.RECEIVER)).getType();
    SSAInstructionFactory insts =
        ((TypeAbstraction) context.get(ContextKey.RECEIVER))
            .getType()
            .getClassLoader()
            .getInstructionFactory();
    if (cls != null) {
      for (IMethod m : returnValues) {
        int c = nextLocal++;
        constants.put(c, new ConstantValue(m));
        SSAReturnInstruction R = insts.ReturnInstruction(statements.size(), c, false);
        statements.add(R);
      }
    } else {
      // SJF: This is incorrect. TODO: fix and enable.
      // SSAThrowInstruction t = insts.ThrowInstruction(retValue);
      // statements.add(t);
    }
    return statements.toArray(new SSAInstruction[0]);
  }

  private static SSAInstruction[] makeGetMethodStatements(
      Context context, Map constants, Atom name) {
    IClass cls = ((TypeAbstraction) context.get(ContextKey.RECEIVER)).getType();
    if (cls == null) {
      return getParticularMethodStatements(GET_METHOD, null, context, constants);
    } else {
      return getParticularMethodStatements(
          GET_METHOD, getAllNormalPublicMethods(cls, name), context, constants);
    }
  }

  /** Create statements for {@link Class#getDeclaredMethod(String, Class...)}. */
  private static SSAInstruction[] makeGetDeclaredMethodStatements(
      Context context, Map constants, Atom name) {
    IClass cls = ((TypeAbstraction) context.get(ContextKey.RECEIVER)).getType();
    if (cls == null) {
      return getParticularMethodStatements(GET_DECLARED_METHOD, null, context, constants);
    } else {
      return getParticularMethodStatements(
          GET_DECLARED_METHOD, getDeclaredNormalMethods(cls, name), context, constants);
    }
  }

  @Override
  public boolean recordFactoryType(CGNode node, IClass klass) {
    return false;
  }

  @Override
  public Iterator iterateFieldsRead(CGNode node) {
    return EmptyIterator.instance();
  }

  @Override
  public Iterator iterateFieldsWritten(CGNode node) {
    return EmptyIterator.instance();
  }

  @Override
  public ControlFlowGraph getCFG(CGNode N) {
    return getIR(N).getControlFlowGraph();
  }

  @Override
  public DefUse getDU(CGNode node) {
    return new DefUse(getIR(node));
  }
}