jdk/src/share/classes/sun/invoke/anon/ConstantPoolVisitor.java
changeset 8822 8145ab9f5f86
parent 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/invoke/anon/ConstantPoolVisitor.java	Wed Mar 23 23:02:31 2011 -0700
@@ -0,0 +1,192 @@
+/*
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.invoke.anon;
+
+/**
+ * A visitor called by {@link ConstantPoolParser#parse(ConstantPoolVisitor)}
+ * when a constant pool entry is parsed.
+ * <p>
+ * A visit* method is called when a constant pool entry is parsed.
+ * The first argument is always the constant pool index.
+ * The second argument is always the constant pool tag,
+ * even for methods like {@link #visitUTF8(int, byte, String)} which only apply to one tag.
+ * String arguments refer to Utf8 or NameAndType entries declared elsewhere,
+ * and are always accompanied by the indexes of those entries.
+ * <p>
+ * The order of the calls to the visit* methods is not necessarily related
+ * to the order of the entries in the constant pool.
+ * If one entry has a reference to another entry, the latter (lower-level)
+ * entry will be visited first.
+ * <p>
+ * The following table shows the relation between constant pool entry
+ * types and the corresponding visit* methods:
+ *
+ * <table border=1 cellpadding=5 summary="constant pool visitor methods">
+ * <tr><th>Tag(s)</th><th>Method</th></tr>
+ * <tr>
+ *   <td>{@link #CONSTANT_Utf8}</td>
+ *   <td>{@link #visitUTF8(int, byte, String)}</td>
+ * </tr><tr>
+ *   <td>{@link #CONSTANT_Integer}, {@link #CONSTANT_Float},
+ *       {@link #CONSTANT_Long}, {@link #CONSTANT_Double}</td>
+ *   <td>{@link #visitConstantValue(int, byte, Object)}</td>
+ * </tr><tr>
+ *   <td>{@link #CONSTANT_String}, {@link #CONSTANT_Class}</td>
+ *   <td>{@link #visitConstantString(int, byte, String, int)}</td>
+ * </tr><tr>
+ *   <td>{@link #CONSTANT_NameAndType}</td>
+ *   <td>{@link #visitDescriptor(int, byte, String, String, int, int)}</td>
+ * </tr><tr>
+ *   <td>{@link #CONSTANT_Fieldref},
+ *       {@link #CONSTANT_Methodref},
+ *       {@link #CONSTANT_InterfaceMethodref}</td>
+ *   <td>{@link #visitMemberRef(int, byte, String, String, String, int, int)}</td>
+ * </tr>
+ * </table>
+ *
+ * @see ConstantPoolPatch
+ * @author Remi Forax
+ * @author jrose
+ */
+public class ConstantPoolVisitor {
+  /** Called each time an UTF8 constant pool entry is found.
+   * @param index the constant pool index
+   * @param tag always {@link #CONSTANT_Utf8}
+   * @param utf8 string encoded in modified UTF-8 format passed as a {@code String}
+   *
+   * @see ConstantPoolPatch#putUTF8(int, String)
+   */
+  public void visitUTF8(int index, byte tag, String utf8) {
+    // do nothing
+  }
+
+  /** Called for each constant pool entry that encodes an integer,
+   *  a float, a long, or a double.
+   *  Constant strings and classes are not managed by this method but
+   *  by {@link #visitConstantString(int, byte, String, int)}.
+   *
+   * @param index the constant pool index
+   * @param tag one of {@link #CONSTANT_Integer},
+   *            {@link #CONSTANT_Float},
+   *            {@link #CONSTANT_Long},
+   *            or {@link #CONSTANT_Double}
+   * @param value encoded value
+   *
+   * @see ConstantPoolPatch#putConstantValue(int, Object)
+   */
+  public void visitConstantValue(int index, byte tag, Object value) {
+    // do nothing
+  }
+
+  /** Called for each constant pool entry that encodes a string or a class.
+   * @param index the constant pool index
+   * @param tag one of {@link #CONSTANT_String},
+   *            {@link #CONSTANT_Class},
+   * @param name string body or class name (using dot separator)
+   * @param nameIndex the index of the Utf8 string for the name
+   *
+   * @see ConstantPoolPatch#putConstantValue(int, byte, Object)
+   */
+  public void visitConstantString(int index, byte tag,
+                                  String name, int nameIndex) {
+    // do nothing
+  }
+
+  /** Called for each constant pool entry that encodes a name and type.
+   * @param index the constant pool index
+   * @param tag always {@link #CONSTANT_NameAndType}
+   * @param memberName a field or method name
+   * @param signature the member signature
+   * @param memberNameIndex index of the Utf8 string for the member name
+   * @param signatureIndex index of the Utf8 string for the signature
+   *
+   * @see ConstantPoolPatch#putDescriptor(int, String, String)
+   */
+  public void visitDescriptor(int index, byte tag,
+                              String memberName, String signature,
+                              int memberNameIndex, int signatureIndex) {
+    // do nothing
+  }
+
+  /** Called for each constant pool entry that encodes a field or method.
+   * @param index the constant pool index
+   * @param tag one of {@link #CONSTANT_Fieldref},
+   *            or {@link #CONSTANT_Methodref},
+   *            or {@link #CONSTANT_InterfaceMethodref}
+   * @param className the class name (using dot separator)
+   * @param memberName name of the field or method
+   * @param signature the field or method signature
+   * @param classNameIndex index of the Utf8 string for the class name
+   * @param descriptorIndex index of the NameAndType descriptor constant
+   *
+   * @see ConstantPoolPatch#putMemberRef(int, byte, String, String, String)
+   */
+  public void visitMemberRef(int index, byte tag,
+                             String className, String memberName, String signature,
+                             int classNameIndex, int descriptorIndex) {
+    // do nothing
+  }
+
+    public static final byte
+      CONSTANT_None = 0,
+      CONSTANT_Utf8 = 1,
+      //CONSTANT_Unicode = 2,               /* unused */
+      CONSTANT_Integer = 3,
+      CONSTANT_Float = 4,
+      CONSTANT_Long = 5,
+      CONSTANT_Double = 6,
+      CONSTANT_Class = 7,
+      CONSTANT_String = 8,
+      CONSTANT_Fieldref = 9,
+      CONSTANT_Methodref = 10,
+      CONSTANT_InterfaceMethodref = 11,
+      CONSTANT_NameAndType = 12;
+
+    private static String[] TAG_NAMES = {
+        "Empty",
+        "Utf8",
+        null, //"Unicode",
+        "Integer",
+        "Float",
+        "Long",
+        "Double",
+        "Class",
+        "String",
+        "Fieldref",
+        "Methodref",
+        "InterfaceMethodref",
+        "NameAndType"
+    };
+
+    public static String tagName(byte tag) {
+        String name = null;
+        if ((tag & 0xFF) < TAG_NAMES.length)
+            name = TAG_NAMES[tag];
+        if (name == null)
+            name = "Unknown#"+(tag&0xFF);
+        return name;
+    }
+}