jack/src/com/android/jack/dx/dex/file/EncodedMethod.java

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.jack.dx.dex.file;

import com.android.jack.dx.rop.code.AccessFlags;
import com.android.jack.dx.rop.cst.CstMethodRef;
import com.android.jack.dx.rop.cst.CstString;
import com.android.jack.dx.util.AnnotatedOutput;
import com.android.jack.dx.util.Hex;
import com.android.jack.dx.util.Leb128Utils;

import java.io.PrintWriter;

/**
 * Class that representats a method of a class.
 */
public final class EncodedMethod extends EncodedMember implements Comparable<EncodedMethod> {
  /** {@code non-null;} constant for the method */
  private final CstMethodRef method;

  /**
   * {@code null-ok;} code for the method, if the method is neither
   * {@code abstract} nor {@code native}
   */
  private final OffsettedItem code;

  /**
   * Constructs an instance.
   *
   * @param method {@code non-null;} constant for the method
   * @param accessFlags access flags
   * @param code {@code null-ok;} code for the method, if it is neither
   * {@code abstract} nor {@code native}
   */
  public EncodedMethod(CstMethodRef method, int accessFlags, OffsettedItem code) {
    super(accessFlags);
    assert code == null || code instanceof Code;
    assert method != null;
    this.method = method;
    this.code = code;
  }

  /** {@inheritDoc} */
  @Override
  public boolean equals(Object other) {
    if (!(other instanceof EncodedMethod)) {
      return false;
    }

    return compareTo((EncodedMethod) other) == 0;
  }

  @Override
  public int hashCode() {
    return method.hashCode();
  }

  /**
   * {@inheritDoc}
   *
   * <p><b>Note:</b> This compares the method constants only,
   * ignoring any associated code, because it should never be the
   * case that two different items with the same method constant
   * ever appear in the same list (or same file, even).</p>
   */
  @Override
  public int compareTo(EncodedMethod other) {
    return method.compareTo(other.method);
  }

  /** {@inheritDoc} */
  @Override
  public String toString() {
    StringBuffer sb = new StringBuffer(100);

    sb.append(getClass().getName());
    sb.append('{');
    sb.append(Hex.u2(getAccessFlags()));
    sb.append(' ');
    sb.append(method);

    if (code != null) {
      sb.append(' ');
      sb.append(code);
    }

    sb.append('}');

    return sb.toString();
  }

  /** {@inheritDoc} */
  @Override
  public void addContents(DexFile file) {
    MethodIdsSection methodIds = file.getMethodIds();
    MixedItemSection wordData = file.getWordData();

    methodIds.intern(method);

    if (code != null) {
      wordData.add(code);
    }
  }

  /** {@inheritDoc} */
  @Override
  public final String toHuman() {
    return method.toHuman();
  }

  /** {@inheritDoc} */
  @Override
  public final CstString getName() {
    return method.getName();
  }

  /** {@inheritDoc} */
  @Override
  public void debugPrint(PrintWriter out, boolean verbose) {
    if (code == null) {
      out.println(getRef().toHuman() + ": abstract or native");
    } else {
      ((Code) code).debugPrint(out, "  ", verbose);
    }
  }

  /**
   * Gets the constant for the method.
   *
   * @return {@code non-null;} the constant
   */
  public final CstMethodRef getRef() {
    return method;
  }

  /** {@inheritDoc} */
  @Override
  public int encode(DexFile file, AnnotatedOutput out, int lastIndex, int dumpSeq) {
    int methodIdx = file.getMethodIds().indexOf(method);
    int diff = methodIdx - lastIndex;
    int accessFlags = getAccessFlags();
    int codeOff = OffsettedItem.getAbsoluteOffsetOr0(code);
    boolean hasCode = (codeOff != 0);
    boolean shouldHaveCode =
        (accessFlags & (AccessFlags.ACC_ABSTRACT | AccessFlags.ACC_NATIVE)) == 0;

    /*
     * Verify that code appears if and only if a method is
     * declared to have it.
     */
    if (hasCode != shouldHaveCode) {
      throw new UnsupportedOperationException("code vs. access_flags mismatch");
    }

    if (out.annotates()) {
      out.annotate(0, String.format("  [%x] %s", Integer.valueOf(dumpSeq), method.toHuman()));
      out.annotate(Leb128Utils.unsignedLeb128Size(diff), "    method_idx:   " + Hex.u4(methodIdx));
      out.annotate(Leb128Utils.unsignedLeb128Size(accessFlags),
          "    access_flags: " + AccessFlags.methodString(accessFlags));
      out.annotate(Leb128Utils.unsignedLeb128Size(codeOff), "    code_off:     " + Hex.u4(codeOff));
    }

    out.writeUleb128(diff);
    out.writeUleb128(accessFlags);
    out.writeUleb128(codeOff);

    return methodIdx;
  }
}