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With inspiration from other libraries
// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
package org.mvel2.asm;
/**
* The constant pool entries, the BootstrapMethods attribute entries and the (ASM specific) type
* table entries of a class.
*
* @see JVMS
* 4.4
* @see JVMS
* 4.7.23
* @author Eric Bruneton
*/
final class SymbolTable {
/**
* The ClassWriter to which this SymbolTable belongs. This is only used to get access to {@link
* ClassWriter#getCommonSuperClass} and to serialize custom attributes with {@link
* Attribute#write}.
*/
final ClassWriter classWriter;
/**
* The ClassReader from which this SymbolTable was constructed, or {@literal null} if it was
* constructed from scratch.
*/
private final ClassReader sourceClassReader;
/** The major version number of the class to which this symbol table belongs. */
private int majorVersion;
/** The internal name of the class to which this symbol table belongs. */
private String className;
/**
* The total number of {@link Entry} instances in {@link #entries}. This includes entries that are
* accessible (recursively) via {@link Entry#next}.
*/
private int entryCount;
/**
* A hash set of all the entries in this SymbolTable (this includes the constant pool entries, the
* bootstrap method entries and the type table entries). Each {@link Entry} instance is stored at
* the array index given by its hash code modulo the array size. If several entries must be stored
* at the same array index, they are linked together via their {@link Entry#next} field. The
* factory methods of this class make sure that this table does not contain duplicated entries.
*/
private Entry[] entries;
/**
* The number of constant pool items in {@link #constantPool}, plus 1. The first constant pool
* item has index 1, and long and double items count for two items.
*/
private int constantPoolCount;
/**
* The content of the ClassFile's constant_pool JVMS structure corresponding to this SymbolTable.
* The ClassFile's constant_pool_count field is not included.
*/
private ByteVector constantPool;
/**
* The number of bootstrap methods in {@link #bootstrapMethods}. Corresponds to the
* BootstrapMethods_attribute's num_bootstrap_methods field value.
*/
private int bootstrapMethodCount;
/**
* The content of the BootstrapMethods attribute 'bootstrap_methods' array corresponding to this
* SymbolTable. Note that the first 6 bytes of the BootstrapMethods_attribute, and its
* num_bootstrap_methods field, are not included.
*/
private ByteVector bootstrapMethods;
/**
* The actual number of elements in {@link #typeTable}. These elements are stored from index 0 to
* typeCount (excluded). The other array entries are empty.
*/
private int typeCount;
/**
* An ASM specific type table used to temporarily store internal names that will not necessarily
* be stored in the constant pool. This type table is used by the control flow and data flow
* analysis algorithm used to compute stack map frames from scratch. This array stores {@link
* Symbol#TYPE_TAG} and {@link Symbol#UNINITIALIZED_TYPE_TAG}) Symbol. The type symbol at index
* {@code i} has its {@link Symbol#index} equal to {@code i} (and vice versa).
*/
private Entry[] typeTable;
/**
* Constructs a new, empty SymbolTable for the given ClassWriter.
*
* @param classWriter a ClassWriter.
*/
SymbolTable(final ClassWriter classWriter) {
this.classWriter = classWriter;
this.sourceClassReader = null;
this.entries = new Entry[256];
this.constantPoolCount = 1;
this.constantPool = new ByteVector();
}
/**
* Constructs a new SymbolTable for the given ClassWriter, initialized with the constant pool and
* bootstrap methods of the given ClassReader.
*
* @param classWriter a ClassWriter.
* @param classReader the ClassReader whose constant pool and bootstrap methods must be copied to
* initialize the SymbolTable.
*/
SymbolTable(final ClassWriter classWriter, final ClassReader classReader) {
this.classWriter = classWriter;
this.sourceClassReader = classReader;
// Copy the constant pool binary content.
byte[] inputBytes = classReader.b;
int constantPoolOffset = classReader.getItem(1) - 1;
int constantPoolLength = classReader.header - constantPoolOffset;
constantPoolCount = classReader.getItemCount();
constantPool = new ByteVector(constantPoolLength);
constantPool.putByteArray(inputBytes, constantPoolOffset, constantPoolLength);
// Add the constant pool items in the symbol table entries. Reserve enough space in 'entries' to
// avoid too many hash set collisions (entries is not dynamically resized by the addConstant*
// method calls below), and to account for bootstrap method entries.
entries = new Entry[constantPoolCount * 2];
char[] charBuffer = new char[classReader.getMaxStringLength()];
boolean hasBootstrapMethods = false;
int itemIndex = 1;
while (itemIndex < constantPoolCount) {
int itemOffset = classReader.getItem(itemIndex);
int itemTag = inputBytes[itemOffset - 1];
int nameAndTypeItemOffset;
switch (itemTag) {
case Symbol.CONSTANT_FIELDREF_TAG:
case Symbol.CONSTANT_METHODREF_TAG:
case Symbol.CONSTANT_INTERFACE_METHODREF_TAG:
nameAndTypeItemOffset =
classReader.getItem(classReader.readUnsignedShort(itemOffset + 2));
addConstantMemberReference(
itemIndex,
itemTag,
classReader.readClass(itemOffset, charBuffer),
classReader.readUTF8(nameAndTypeItemOffset, charBuffer),
classReader.readUTF8(nameAndTypeItemOffset + 2, charBuffer));
break;
case Symbol.CONSTANT_INTEGER_TAG:
case Symbol.CONSTANT_FLOAT_TAG:
addConstantIntegerOrFloat(itemIndex, itemTag, classReader.readInt(itemOffset));
break;
case Symbol.CONSTANT_NAME_AND_TYPE_TAG:
addConstantNameAndType(
itemIndex,
classReader.readUTF8(itemOffset, charBuffer),
classReader.readUTF8(itemOffset + 2, charBuffer));
break;
case Symbol.CONSTANT_LONG_TAG:
case Symbol.CONSTANT_DOUBLE_TAG:
addConstantLongOrDouble(itemIndex, itemTag, classReader.readLong(itemOffset));
break;
case Symbol.CONSTANT_UTF8_TAG:
addConstantUtf8(itemIndex, classReader.readUtf(itemIndex, charBuffer));
break;
case Symbol.CONSTANT_METHOD_HANDLE_TAG:
int memberRefItemOffset =
classReader.getItem(classReader.readUnsignedShort(itemOffset + 1));
nameAndTypeItemOffset =
classReader.getItem(classReader.readUnsignedShort(memberRefItemOffset + 2));
addConstantMethodHandle(
itemIndex,
classReader.readByte(itemOffset),
classReader.readClass(memberRefItemOffset, charBuffer),
classReader.readUTF8(nameAndTypeItemOffset, charBuffer),
classReader.readUTF8(nameAndTypeItemOffset + 2, charBuffer));
break;
case Symbol.CONSTANT_DYNAMIC_TAG:
case Symbol.CONSTANT_INVOKE_DYNAMIC_TAG:
hasBootstrapMethods = true;
nameAndTypeItemOffset =
classReader.getItem(classReader.readUnsignedShort(itemOffset + 2));
addConstantDynamicOrInvokeDynamicReference(
itemTag,
itemIndex,
classReader.readUTF8(nameAndTypeItemOffset, charBuffer),
classReader.readUTF8(nameAndTypeItemOffset + 2, charBuffer),
classReader.readUnsignedShort(itemOffset));
break;
case Symbol.CONSTANT_STRING_TAG:
case Symbol.CONSTANT_CLASS_TAG:
case Symbol.CONSTANT_METHOD_TYPE_TAG:
case Symbol.CONSTANT_MODULE_TAG:
case Symbol.CONSTANT_PACKAGE_TAG:
addConstantUtf8Reference(
itemIndex, itemTag, classReader.readUTF8(itemOffset, charBuffer));
break;
default:
throw new IllegalArgumentException();
}
itemIndex +=
(itemTag == Symbol.CONSTANT_LONG_TAG || itemTag == Symbol.CONSTANT_DOUBLE_TAG) ? 2 : 1;
}
// Copy the BootstrapMethods, if any.
if (hasBootstrapMethods) {
copyBootstrapMethods(classReader, charBuffer);
}
}
/**
* Read the BootstrapMethods 'bootstrap_methods' array binary content and add them as entries of
* the SymbolTable.
*
* @param classReader the ClassReader whose bootstrap methods must be copied to initialize the
* SymbolTable.
* @param charBuffer a buffer used to read strings in the constant pool.
*/
private void copyBootstrapMethods(final ClassReader classReader, final char[] charBuffer) {
// Find attributOffset of the 'bootstrap_methods' array.
byte[] inputBytes = classReader.b;
int currentAttributeOffset = classReader.getFirstAttributeOffset();
for (int i = classReader.readUnsignedShort(currentAttributeOffset - 2); i > 0; --i) {
String attributeName = classReader.readUTF8(currentAttributeOffset, charBuffer);
if (Constants.BOOTSTRAP_METHODS.equals(attributeName)) {
bootstrapMethodCount = classReader.readUnsignedShort(currentAttributeOffset + 6);
break;
}
currentAttributeOffset += 6 + classReader.readInt(currentAttributeOffset + 2);
}
if (bootstrapMethodCount > 0) {
// Compute the offset and the length of the BootstrapMethods 'bootstrap_methods' array.
int bootstrapMethodsOffset = currentAttributeOffset + 8;
int bootstrapMethodsLength = classReader.readInt(currentAttributeOffset + 2) - 2;
bootstrapMethods = new ByteVector(bootstrapMethodsLength);
bootstrapMethods.putByteArray(inputBytes, bootstrapMethodsOffset, bootstrapMethodsLength);
// Add each bootstrap method in the symbol table entries.
int currentOffset = bootstrapMethodsOffset;
for (int i = 0; i < bootstrapMethodCount; i++) {
int offset = currentOffset - bootstrapMethodsOffset;
int bootstrapMethodRef = classReader.readUnsignedShort(currentOffset);
currentOffset += 2;
int numBootstrapArguments = classReader.readUnsignedShort(currentOffset);
currentOffset += 2;
int hashCode = classReader.readConst(bootstrapMethodRef, charBuffer).hashCode();
while (numBootstrapArguments-- > 0) {
int bootstrapArgument = classReader.readUnsignedShort(currentOffset);
currentOffset += 2;
hashCode ^= classReader.readConst(bootstrapArgument, charBuffer).hashCode();
}
add(new Entry(i, Symbol.BOOTSTRAP_METHOD_TAG, offset, hashCode & 0x7FFFFFFF));
}
}
}
/**
* Returns the ClassReader from which this SymbolTable was constructed.
*
* @return the ClassReader from which this SymbolTable was constructed, or {@literal null} if it
* was constructed from scratch.
*/
ClassReader getSource() {
return sourceClassReader;
}
/**
* Returns the major version of the class to which this symbol table belongs.
*
* @return the major version of the class to which this symbol table belongs.
*/
int getMajorVersion() {
return majorVersion;
}
/**
* Returns the internal name of the class to which this symbol table belongs.
*
* @return the internal name of the class to which this symbol table belongs.
*/
String getClassName() {
return className;
}
/**
* Sets the major version and the name of the class to which this symbol table belongs. Also adds
* the class name to the constant pool.
*
* @param majorVersion a major ClassFile version number.
* @param className an internal class name.
* @return the constant pool index of a new or already existing Symbol with the given class name.
*/
int setMajorVersionAndClassName(final int majorVersion, final String className) {
this.majorVersion = majorVersion;
this.className = className;
return addConstantClass(className).index;
}
/**
* Returns the number of items in this symbol table's constant_pool array (plus 1).
*
* @return the number of items in this symbol table's constant_pool array (plus 1).
*/
int getConstantPoolCount() {
return constantPoolCount;
}
/**
* Returns the length in bytes of this symbol table's constant_pool array.
*
* @return the length in bytes of this symbol table's constant_pool array.
*/
int getConstantPoolLength() {
return constantPool.length;
}
/**
* Puts this symbol table's constant_pool array in the given ByteVector, preceded by the
* constant_pool_count value.
*
* @param output where the JVMS ClassFile's constant_pool array must be put.
*/
void putConstantPool(final ByteVector output) {
output.putShort(constantPoolCount).putByteArray(constantPool.data, 0, constantPool.length);
}
/**
* Returns the size in bytes of this symbol table's BootstrapMethods attribute. Also adds the
* attribute name in the constant pool.
*
* @return the size in bytes of this symbol table's BootstrapMethods attribute.
*/
int computeBootstrapMethodsSize() {
if (bootstrapMethods != null) {
addConstantUtf8(Constants.BOOTSTRAP_METHODS);
return 8 + bootstrapMethods.length;
} else {
return 0;
}
}
/**
* Puts this symbol table's BootstrapMethods attribute in the given ByteVector. This includes the
* 6 attribute header bytes and the num_bootstrap_methods value.
*
* @param output where the JVMS BootstrapMethods attribute must be put.
*/
void putBootstrapMethods(final ByteVector output) {
if (bootstrapMethods != null) {
output
.putShort(addConstantUtf8(Constants.BOOTSTRAP_METHODS))
.putInt(bootstrapMethods.length + 2)
.putShort(bootstrapMethodCount)
.putByteArray(bootstrapMethods.data, 0, bootstrapMethods.length);
}
}
// -----------------------------------------------------------------------------------------------
// Generic symbol table entries management.
// -----------------------------------------------------------------------------------------------
/**
* Returns the list of entries which can potentially have the given hash code.
*
* @param hashCode a {@link Entry#hashCode} value.
* @return the list of entries which can potentially have the given hash code. The list is stored
* via the {@link Entry#next} field.
*/
private Entry get(final int hashCode) {
return entries[hashCode % entries.length];
}
/**
* Puts the given entry in the {@link #entries} hash set. This method does not check
* whether {@link #entries} already contains a similar entry or not. {@link #entries} is resized
* if necessary to avoid hash collisions (multiple entries needing to be stored at the same {@link
* #entries} array index) as much as possible, with reasonable memory usage.
*
* @param entry an Entry (which must not already be contained in {@link #entries}).
* @return the given entry
*/
private Entry put(final Entry entry) {
if (entryCount > (entries.length * 3) / 4) {
int currentCapacity = entries.length;
int newCapacity = currentCapacity * 2 + 1;
Entry[] newEntries = new Entry[newCapacity];
for (int i = currentCapacity - 1; i >= 0; --i) {
Entry currentEntry = entries[i];
while (currentEntry != null) {
int newCurrentEntryIndex = currentEntry.hashCode % newCapacity;
Entry nextEntry = currentEntry.next;
currentEntry.next = newEntries[newCurrentEntryIndex];
newEntries[newCurrentEntryIndex] = currentEntry;
currentEntry = nextEntry;
}
}
entries = newEntries;
}
entryCount++;
int index = entry.hashCode % entries.length;
entry.next = entries[index];
return entries[index] = entry;
}
/**
* Adds the given entry in the {@link #entries} hash set. This method does not check
* whether {@link #entries} already contains a similar entry or not, and does not resize
* {@link #entries} if necessary.
*
* @param entry an Entry (which must not already be contained in {@link #entries}).
*/
private void add(final Entry entry) {
entryCount++;
int index = entry.hashCode % entries.length;
entry.next = entries[index];
entries[index] = entry;
}
// -----------------------------------------------------------------------------------------------
// Constant pool entries management.
// -----------------------------------------------------------------------------------------------
/**
* Adds a number or string constant to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value the value of the constant to be added to the constant pool. This parameter must be
* an {@link Integer}, {@link Byte}, {@link Character}, {@link Short}, {@link Boolean}, {@link
* Float}, {@link Long}, {@link Double}, {@link String}, {@link Type} or {@link Handle}.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstant(final Object value) {
if (value instanceof Integer) {
return addConstantInteger(((Integer) value).intValue());
} else if (value instanceof Byte) {
return addConstantInteger(((Byte) value).intValue());
} else if (value instanceof Character) {
return addConstantInteger(((Character) value).charValue());
} else if (value instanceof Short) {
return addConstantInteger(((Short) value).intValue());
} else if (value instanceof Boolean) {
return addConstantInteger(((Boolean) value).booleanValue() ? 1 : 0);
} else if (value instanceof Float) {
return addConstantFloat(((Float) value).floatValue());
} else if (value instanceof Long) {
return addConstantLong(((Long) value).longValue());
} else if (value instanceof Double) {
return addConstantDouble(((Double) value).doubleValue());
} else if (value instanceof String) {
return addConstantString((String) value);
} else if (value instanceof Type) {
Type type = (Type) value;
int typeSort = type.getSort();
if (typeSort == Type.OBJECT) {
return addConstantClass(type.getInternalName());
} else if (typeSort == Type.METHOD) {
return addConstantMethodType(type.getDescriptor());
} else { // type is a primitive or array type.
return addConstantClass(type.getDescriptor());
}
} else if (value instanceof Handle) {
Handle handle = (Handle) value;
return addConstantMethodHandle(
handle.getTag(),
handle.getOwner(),
handle.getName(),
handle.getDesc(),
handle.isInterface());
} else if (value instanceof ConstantDynamic) {
ConstantDynamic constantDynamic = (ConstantDynamic) value;
return addConstantDynamic(
constantDynamic.getName(),
constantDynamic.getDescriptor(),
constantDynamic.getBootstrapMethod(),
constantDynamic.getBootstrapMethodArgumentsUnsafe());
} else {
throw new IllegalArgumentException("value " + value);
}
}
/**
* Adds a CONSTANT_Class_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value the internal name of a class.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantClass(final String value) {
return addConstantUtf8Reference(Symbol.CONSTANT_CLASS_TAG, value);
}
/**
* Adds a CONSTANT_Fieldref_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param owner the internal name of a class.
* @param name a field name.
* @param descriptor a field descriptor.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantFieldref(final String owner, final String name, final String descriptor) {
return addConstantMemberReference(Symbol.CONSTANT_FIELDREF_TAG, owner, name, descriptor);
}
/**
* Adds a CONSTANT_Methodref_info or CONSTANT_InterfaceMethodref_info to the constant pool of this
* symbol table. Does nothing if the constant pool already contains a similar item.
*
* @param owner the internal name of a class.
* @param name a method name.
* @param descriptor a method descriptor.
* @param isInterface whether owner is an interface or not.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantMethodref(
final String owner, final String name, final String descriptor, final boolean isInterface) {
int tag = isInterface ? Symbol.CONSTANT_INTERFACE_METHODREF_TAG : Symbol.CONSTANT_METHODREF_TAG;
return addConstantMemberReference(tag, owner, name, descriptor);
}
/**
* Adds a CONSTANT_Fieldref_info, CONSTANT_Methodref_info or CONSTANT_InterfaceMethodref_info to
* the constant pool of this symbol table. Does nothing if the constant pool already contains a
* similar item.
*
* @param tag one of {@link Symbol#CONSTANT_FIELDREF_TAG}, {@link Symbol#CONSTANT_METHODREF_TAG}
* or {@link Symbol#CONSTANT_INTERFACE_METHODREF_TAG}.
* @param owner the internal name of a class.
* @param name a field or method name.
* @param descriptor a field or method descriptor.
* @return a new or already existing Symbol with the given value.
*/
private Entry addConstantMemberReference(
final int tag, final String owner, final String name, final String descriptor) {
int hashCode = hash(tag, owner, name, descriptor);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag
&& entry.hashCode == hashCode
&& entry.owner.equals(owner)
&& entry.name.equals(name)
&& entry.value.equals(descriptor)) {
return entry;
}
entry = entry.next;
}
constantPool.put122(
tag, addConstantClass(owner).index, addConstantNameAndType(name, descriptor));
return put(new Entry(constantPoolCount++, tag, owner, name, descriptor, 0, hashCode));
}
/**
* Adds a new CONSTANT_Fieldref_info, CONSTANT_Methodref_info or CONSTANT_InterfaceMethodref_info
* to the constant pool of this symbol table.
*
* @param index the constant pool index of the new Symbol.
* @param tag one of {@link Symbol#CONSTANT_FIELDREF_TAG}, {@link Symbol#CONSTANT_METHODREF_TAG}
* or {@link Symbol#CONSTANT_INTERFACE_METHODREF_TAG}.
* @param owner the internal name of a class.
* @param name a field or method name.
* @param descriptor a field or method descriptor.
*/
private void addConstantMemberReference(
final int index,
final int tag,
final String owner,
final String name,
final String descriptor) {
add(new Entry(index, tag, owner, name, descriptor, 0, hash(tag, owner, name, descriptor)));
}
/**
* Adds a CONSTANT_String_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value a string.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantString(final String value) {
return addConstantUtf8Reference(Symbol.CONSTANT_STRING_TAG, value);
}
/**
* Adds a CONSTANT_Integer_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value an int.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantInteger(final int value) {
return addConstantIntegerOrFloat(Symbol.CONSTANT_INTEGER_TAG, value);
}
/**
* Adds a CONSTANT_Float_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value a float.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantFloat(final float value) {
return addConstantIntegerOrFloat(Symbol.CONSTANT_FLOAT_TAG, Float.floatToRawIntBits(value));
}
/**
* Adds a CONSTANT_Integer_info or CONSTANT_Float_info to the constant pool of this symbol table.
* Does nothing if the constant pool already contains a similar item.
*
* @param tag one of {@link Symbol#CONSTANT_INTEGER_TAG} or {@link Symbol#CONSTANT_FLOAT_TAG}.
* @param value an int or float.
* @return a constant pool constant with the given tag and primitive values.
*/
private Symbol addConstantIntegerOrFloat(final int tag, final int value) {
int hashCode = hash(tag, value);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag && entry.hashCode == hashCode && entry.data == value) {
return entry;
}
entry = entry.next;
}
constantPool.putByte(tag).putInt(value);
return put(new Entry(constantPoolCount++, tag, value, hashCode));
}
/**
* Adds a new CONSTANT_Integer_info or CONSTANT_Float_info to the constant pool of this symbol
* table.
*
* @param index the constant pool index of the new Symbol.
* @param tag one of {@link Symbol#CONSTANT_INTEGER_TAG} or {@link Symbol#CONSTANT_FLOAT_TAG}.
* @param value an int or float.
*/
private void addConstantIntegerOrFloat(final int index, final int tag, final int value) {
add(new Entry(index, tag, value, hash(tag, value)));
}
/**
* Adds a CONSTANT_Long_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value a long.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantLong(final long value) {
return addConstantLongOrDouble(Symbol.CONSTANT_LONG_TAG, value);
}
/**
* Adds a CONSTANT_Double_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value a double.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantDouble(final double value) {
return addConstantLongOrDouble(Symbol.CONSTANT_DOUBLE_TAG, Double.doubleToRawLongBits(value));
}
/**
* Adds a CONSTANT_Long_info or CONSTANT_Double_info to the constant pool of this symbol table.
* Does nothing if the constant pool already contains a similar item.
*
* @param tag one of {@link Symbol#CONSTANT_LONG_TAG} or {@link Symbol#CONSTANT_DOUBLE_TAG}.
* @param value a long or double.
* @return a constant pool constant with the given tag and primitive values.
*/
private Symbol addConstantLongOrDouble(final int tag, final long value) {
int hashCode = hash(tag, value);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag && entry.hashCode == hashCode && entry.data == value) {
return entry;
}
entry = entry.next;
}
int index = constantPoolCount;
constantPool.putByte(tag).putLong(value);
constantPoolCount += 2;
return put(new Entry(index, tag, value, hashCode));
}
/**
* Adds a new CONSTANT_Long_info or CONSTANT_Double_info to the constant pool of this symbol
* table.
*
* @param index the constant pool index of the new Symbol.
* @param tag one of {@link Symbol#CONSTANT_LONG_TAG} or {@link Symbol#CONSTANT_DOUBLE_TAG}.
* @param value a long or double.
*/
private void addConstantLongOrDouble(final int index, final int tag, final long value) {
add(new Entry(index, tag, value, hash(tag, value)));
}
/**
* Adds a CONSTANT_NameAndType_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param name a field or method name.
* @param descriptor a field or method descriptor.
* @return a new or already existing Symbol with the given value.
*/
int addConstantNameAndType(final String name, final String descriptor) {
final int tag = Symbol.CONSTANT_NAME_AND_TYPE_TAG;
int hashCode = hash(tag, name, descriptor);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag
&& entry.hashCode == hashCode
&& entry.name.equals(name)
&& entry.value.equals(descriptor)) {
return entry.index;
}
entry = entry.next;
}
constantPool.put122(tag, addConstantUtf8(name), addConstantUtf8(descriptor));
return put(new Entry(constantPoolCount++, tag, name, descriptor, hashCode)).index;
}
/**
* Adds a new CONSTANT_NameAndType_info to the constant pool of this symbol table.
*
* @param index the constant pool index of the new Symbol.
* @param name a field or method name.
* @param descriptor a field or method descriptor.
*/
private void addConstantNameAndType(final int index, final String name, final String descriptor) {
final int tag = Symbol.CONSTANT_NAME_AND_TYPE_TAG;
add(new Entry(index, tag, name, descriptor, hash(tag, name, descriptor)));
}
/**
* Adds a CONSTANT_Utf8_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param value a string.
* @return a new or already existing Symbol with the given value.
*/
int addConstantUtf8(final String value) {
int hashCode = hash(Symbol.CONSTANT_UTF8_TAG, value);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == Symbol.CONSTANT_UTF8_TAG
&& entry.hashCode == hashCode
&& entry.value.equals(value)) {
return entry.index;
}
entry = entry.next;
}
constantPool.putByte(Symbol.CONSTANT_UTF8_TAG).putUTF8(value);
return put(new Entry(constantPoolCount++, Symbol.CONSTANT_UTF8_TAG, value, hashCode)).index;
}
/**
* Adds a new CONSTANT_String_info to the constant pool of this symbol table.
*
* @param index the constant pool index of the new Symbol.
* @param value a string.
*/
private void addConstantUtf8(final int index, final String value) {
add(new Entry(index, Symbol.CONSTANT_UTF8_TAG, value, hash(Symbol.CONSTANT_UTF8_TAG, value)));
}
/**
* Adds a CONSTANT_MethodHandle_info to the constant pool of this symbol table. Does nothing if
* the constant pool already contains a similar item.
*
* @param referenceKind one of {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link
* Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link
* Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL}, {@link
* Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
* @param owner the internal name of a class of interface.
* @param name a field or method name.
* @param descriptor a field or method descriptor.
* @param isInterface whether owner is an interface or not.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantMethodHandle(
final int referenceKind,
final String owner,
final String name,
final String descriptor,
final boolean isInterface) {
final int tag = Symbol.CONSTANT_METHOD_HANDLE_TAG;
// Note that we don't need to include isInterface in the hash computation, because it is
// redundant with owner (we can't have the same owner with different isInterface values).
int hashCode = hash(tag, owner, name, descriptor, referenceKind);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag
&& entry.hashCode == hashCode
&& entry.data == referenceKind
&& entry.owner.equals(owner)
&& entry.name.equals(name)
&& entry.value.equals(descriptor)) {
return entry;
}
entry = entry.next;
}
if (referenceKind <= Opcodes.H_PUTSTATIC) {
constantPool.put112(tag, referenceKind, addConstantFieldref(owner, name, descriptor).index);
} else {
constantPool.put112(
tag, referenceKind, addConstantMethodref(owner, name, descriptor, isInterface).index);
}
return put(
new Entry(constantPoolCount++, tag, owner, name, descriptor, referenceKind, hashCode));
}
/**
* Adds a new CONSTANT_MethodHandle_info to the constant pool of this symbol table.
*
* @param index the constant pool index of the new Symbol.
* @param referenceKind one of {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link
* Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link
* Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL}, {@link
* Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
* @param owner the internal name of a class of interface.
* @param name a field or method name.
* @param descriptor a field or method descriptor.
*/
private void addConstantMethodHandle(
final int index,
final int referenceKind,
final String owner,
final String name,
final String descriptor) {
final int tag = Symbol.CONSTANT_METHOD_HANDLE_TAG;
int hashCode = hash(tag, owner, name, descriptor, referenceKind);
add(new Entry(index, tag, owner, name, descriptor, referenceKind, hashCode));
}
/**
* Adds a CONSTANT_MethodType_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param methodDescriptor a method descriptor.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantMethodType(final String methodDescriptor) {
return addConstantUtf8Reference(Symbol.CONSTANT_METHOD_TYPE_TAG, methodDescriptor);
}
/**
* Adds a CONSTANT_Dynamic_info to the constant pool of this symbol table. Also adds the related
* bootstrap method to the BootstrapMethods of this symbol table. Does nothing if the constant
* pool already contains a similar item.
*
* @param name a method name.
* @param descriptor a field descriptor.
* @param bootstrapMethodHandle a bootstrap method handle.
* @param bootstrapMethodArguments the bootstrap method arguments.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantDynamic(
final String name,
final String descriptor,
final Handle bootstrapMethodHandle,
final Object... bootstrapMethodArguments) {
Symbol bootstrapMethod = addBootstrapMethod(bootstrapMethodHandle, bootstrapMethodArguments);
return addConstantDynamicOrInvokeDynamicReference(
Symbol.CONSTANT_DYNAMIC_TAG, name, descriptor, bootstrapMethod.index);
}
/**
* Adds a CONSTANT_InvokeDynamic_info to the constant pool of this symbol table. Also adds the
* related bootstrap method to the BootstrapMethods of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param name a method name.
* @param descriptor a method descriptor.
* @param bootstrapMethodHandle a bootstrap method handle.
* @param bootstrapMethodArguments the bootstrap method arguments.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantInvokeDynamic(
final String name,
final String descriptor,
final Handle bootstrapMethodHandle,
final Object... bootstrapMethodArguments) {
Symbol bootstrapMethod = addBootstrapMethod(bootstrapMethodHandle, bootstrapMethodArguments);
return addConstantDynamicOrInvokeDynamicReference(
Symbol.CONSTANT_INVOKE_DYNAMIC_TAG, name, descriptor, bootstrapMethod.index);
}
/**
* Adds a CONSTANT_Dynamic or a CONSTANT_InvokeDynamic_info to the constant pool of this symbol
* table. Does nothing if the constant pool already contains a similar item.
*
* @param tag one of {@link Symbol#CONSTANT_DYNAMIC_TAG} or {@link
* Symbol#CONSTANT_INVOKE_DYNAMIC_TAG}.
* @param name a method name.
* @param descriptor a field descriptor for CONSTANT_DYNAMIC_TAG) or a method descriptor for
* CONSTANT_INVOKE_DYNAMIC_TAG.
* @param bootstrapMethodIndex the index of a bootstrap method in the BootstrapMethods attribute.
* @return a new or already existing Symbol with the given value.
*/
private Symbol addConstantDynamicOrInvokeDynamicReference(
final int tag, final String name, final String descriptor, final int bootstrapMethodIndex) {
int hashCode = hash(tag, name, descriptor, bootstrapMethodIndex);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag
&& entry.hashCode == hashCode
&& entry.data == bootstrapMethodIndex
&& entry.name.equals(name)
&& entry.value.equals(descriptor)) {
return entry;
}
entry = entry.next;
}
constantPool.put122(tag, bootstrapMethodIndex, addConstantNameAndType(name, descriptor));
return put(
new Entry(
constantPoolCount++, tag, null, name, descriptor, bootstrapMethodIndex, hashCode));
}
/**
* Adds a new CONSTANT_Dynamic_info or CONSTANT_InvokeDynamic_info to the constant pool of this
* symbol table.
*
* @param tag one of {@link Symbol#CONSTANT_DYNAMIC_TAG} or {@link
* Symbol#CONSTANT_INVOKE_DYNAMIC_TAG}.
* @param index the constant pool index of the new Symbol.
* @param name a method name.
* @param descriptor a field descriptor for CONSTANT_DYNAMIC_TAG or a method descriptor for
* CONSTANT_INVOKE_DYNAMIC_TAG.
* @param bootstrapMethodIndex the index of a bootstrap method in the BootstrapMethods attribute.
*/
private void addConstantDynamicOrInvokeDynamicReference(
final int tag,
final int index,
final String name,
final String descriptor,
final int bootstrapMethodIndex) {
int hashCode = hash(tag, name, descriptor, bootstrapMethodIndex);
add(new Entry(index, tag, null, name, descriptor, bootstrapMethodIndex, hashCode));
}
/**
* Adds a CONSTANT_Module_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param moduleName a fully qualified name (using dots) of a module.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantModule(final String moduleName) {
return addConstantUtf8Reference(Symbol.CONSTANT_MODULE_TAG, moduleName);
}
/**
* Adds a CONSTANT_Package_info to the constant pool of this symbol table. Does nothing if the
* constant pool already contains a similar item.
*
* @param packageName the internal name of a package.
* @return a new or already existing Symbol with the given value.
*/
Symbol addConstantPackage(final String packageName) {
return addConstantUtf8Reference(Symbol.CONSTANT_PACKAGE_TAG, packageName);
}
/**
* Adds a CONSTANT_Class_info, CONSTANT_String_info, CONSTANT_MethodType_info,
* CONSTANT_Module_info or CONSTANT_Package_info to the constant pool of this symbol table. Does
* nothing if the constant pool already contains a similar item.
*
* @param tag one of {@link Symbol#CONSTANT_CLASS_TAG}, {@link Symbol#CONSTANT_STRING_TAG}, {@link
* Symbol#CONSTANT_METHOD_TYPE_TAG}, {@link Symbol#CONSTANT_MODULE_TAG} or {@link
* Symbol#CONSTANT_PACKAGE_TAG}.
* @param value an internal class name, an arbitrary string, a method descriptor, a module or a
* package name, depending on tag.
* @return a new or already existing Symbol with the given value.
*/
private Symbol addConstantUtf8Reference(final int tag, final String value) {
int hashCode = hash(tag, value);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == tag && entry.hashCode == hashCode && entry.value.equals(value)) {
return entry;
}
entry = entry.next;
}
constantPool.put12(tag, addConstantUtf8(value));
return put(new Entry(constantPoolCount++, tag, value, hashCode));
}
/**
* Adds a new CONSTANT_Class_info, CONSTANT_String_info, CONSTANT_MethodType_info,
* CONSTANT_Module_info or CONSTANT_Package_info to the constant pool of this symbol table.
*
* @param index the constant pool index of the new Symbol.
* @param tag one of {@link Symbol#CONSTANT_CLASS_TAG}, {@link Symbol#CONSTANT_STRING_TAG}, {@link
* Symbol#CONSTANT_METHOD_TYPE_TAG}, {@link Symbol#CONSTANT_MODULE_TAG} or {@link
* Symbol#CONSTANT_PACKAGE_TAG}.
* @param value an internal class name, an arbitrary string, a method descriptor, a module or a
* package name, depending on tag.
*/
private void addConstantUtf8Reference(final int index, final int tag, final String value) {
add(new Entry(index, tag, value, hash(tag, value)));
}
// -----------------------------------------------------------------------------------------------
// Bootstrap method entries management.
// -----------------------------------------------------------------------------------------------
/**
* Adds a bootstrap method to the BootstrapMethods attribute of this symbol table. Does nothing if
* the BootstrapMethods already contains a similar bootstrap method.
*
* @param bootstrapMethodHandle a bootstrap method handle.
* @param bootstrapMethodArguments the bootstrap method arguments.
* @return a new or already existing Symbol with the given value.
*/
Symbol addBootstrapMethod(
final Handle bootstrapMethodHandle, final Object... bootstrapMethodArguments) {
ByteVector bootstrapMethodsAttribute = bootstrapMethods;
if (bootstrapMethodsAttribute == null) {
bootstrapMethodsAttribute = bootstrapMethods = new ByteVector();
}
// The bootstrap method arguments can be Constant_Dynamic values, which reference other
// bootstrap methods. We must therefore add the bootstrap method arguments to the constant pool
// and BootstrapMethods attribute first, so that the BootstrapMethods attribute is not modified
// while adding the given bootstrap method to it, in the rest of this method.
for (Object bootstrapMethodArgument : bootstrapMethodArguments) {
addConstant(bootstrapMethodArgument);
}
// Write the bootstrap method in the BootstrapMethods table. This is necessary to be able to
// compare it with existing ones, and will be reverted below if there is already a similar
// bootstrap method.
int bootstrapMethodOffset = bootstrapMethodsAttribute.length;
bootstrapMethodsAttribute.putShort(
addConstantMethodHandle(
bootstrapMethodHandle.getTag(),
bootstrapMethodHandle.getOwner(),
bootstrapMethodHandle.getName(),
bootstrapMethodHandle.getDesc(),
bootstrapMethodHandle.isInterface())
.index);
int numBootstrapArguments = bootstrapMethodArguments.length;
bootstrapMethodsAttribute.putShort(numBootstrapArguments);
for (Object bootstrapMethodArgument : bootstrapMethodArguments) {
bootstrapMethodsAttribute.putShort(addConstant(bootstrapMethodArgument).index);
}
// Compute the length and the hash code of the bootstrap method.
int bootstrapMethodlength = bootstrapMethodsAttribute.length - bootstrapMethodOffset;
int hashCode = bootstrapMethodHandle.hashCode();
for (Object bootstrapMethodArgument : bootstrapMethodArguments) {
hashCode ^= bootstrapMethodArgument.hashCode();
}
hashCode &= 0x7FFFFFFF;
// Add the bootstrap method to the symbol table or revert the above changes.
return addBootstrapMethod(bootstrapMethodOffset, bootstrapMethodlength, hashCode);
}
/**
* Adds a bootstrap method to the BootstrapMethods attribute of this symbol table. Does nothing if
* the BootstrapMethods already contains a similar bootstrap method (more precisely, reverts the
* content of {@link #bootstrapMethods} to remove the last, duplicate bootstrap method).
*
* @param offset the offset of the last bootstrap method in {@link #bootstrapMethods}, in bytes.
* @param length the length of this bootstrap method in {@link #bootstrapMethods}, in bytes.
* @param hashCode the hash code of this bootstrap method.
* @return a new or already existing Symbol with the given value.
*/
private Symbol addBootstrapMethod(final int offset, final int length, final int hashCode) {
final byte[] bootstrapMethodsData = bootstrapMethods.data;
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == Symbol.BOOTSTRAP_METHOD_TAG && entry.hashCode == hashCode) {
int otherOffset = (int) entry.data;
boolean isSameBootstrapMethod = true;
for (int i = 0; i < length; ++i) {
if (bootstrapMethodsData[offset + i] != bootstrapMethodsData[otherOffset + i]) {
isSameBootstrapMethod = false;
break;
}
}
if (isSameBootstrapMethod) {
bootstrapMethods.length = offset; // Revert to old position.
return entry;
}
}
entry = entry.next;
}
return put(new Entry(bootstrapMethodCount++, Symbol.BOOTSTRAP_METHOD_TAG, offset, hashCode));
}
// -----------------------------------------------------------------------------------------------
// Type table entries management.
// -----------------------------------------------------------------------------------------------
/**
* Returns the type table element whose index is given.
*
* @param typeIndex a type table index.
* @return the type table element whose index is given.
*/
Symbol getType(final int typeIndex) {
return typeTable[typeIndex];
}
/**
* Adds a type in the type table of this symbol table. Does nothing if the type table already
* contains a similar type.
*
* @param value an internal class name.
* @return the index of a new or already existing type Symbol with the given value.
*/
int addType(final String value) {
int hashCode = hash(Symbol.TYPE_TAG, value);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == Symbol.TYPE_TAG && entry.hashCode == hashCode && entry.value.equals(value)) {
return entry.index;
}
entry = entry.next;
}
return addTypeInternal(new Entry(typeCount, Symbol.TYPE_TAG, value, hashCode));
}
/**
* Adds an {@link Frame#ITEM_UNINITIALIZED} type in the type table of this symbol table. Does
* nothing if the type table already contains a similar type.
*
* @param value an internal class name.
* @param bytecodeOffset the bytecode offset of the NEW instruction that created this {@link
* Frame#ITEM_UNINITIALIZED} type value.
* @return the index of a new or already existing type Symbol with the given value.
*/
int addUninitializedType(final String value, final int bytecodeOffset) {
int hashCode = hash(Symbol.UNINITIALIZED_TYPE_TAG, value, bytecodeOffset);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == Symbol.UNINITIALIZED_TYPE_TAG
&& entry.hashCode == hashCode
&& entry.data == bytecodeOffset
&& entry.value.equals(value)) {
return entry.index;
}
entry = entry.next;
}
return addTypeInternal(
new Entry(typeCount, Symbol.UNINITIALIZED_TYPE_TAG, value, bytecodeOffset, hashCode));
}
/**
* Adds a merged type in the type table of this symbol table. Does nothing if the type table
* already contains a similar type.
*
* @param typeTableIndex1 a {@link Symbol#TYPE_TAG} type, specified by its index in the type
* table.
* @param typeTableIndex2 another {@link Symbol#TYPE_TAG} type, specified by its index in the type
* table.
* @return the index of a new or already existing {@link Symbol#TYPE_TAG} type Symbol,
* corresponding to the common super class of the given types.
*/
int addMergedType(final int typeTableIndex1, final int typeTableIndex2) {
// TODO sort the arguments? The merge result should be independent of their order.
long data = typeTableIndex1 | (((long) typeTableIndex2) << 32);
int hashCode = hash(Symbol.MERGED_TYPE_TAG, typeTableIndex1 + typeTableIndex2);
Entry entry = get(hashCode);
while (entry != null) {
if (entry.tag == Symbol.MERGED_TYPE_TAG && entry.hashCode == hashCode && entry.data == data) {
return entry.info;
}
entry = entry.next;
}
String type1 = typeTable[typeTableIndex1].value;
String type2 = typeTable[typeTableIndex2].value;
int commonSuperTypeIndex = addType(classWriter.getCommonSuperClass(type1, type2));
put(new Entry(typeCount, Symbol.MERGED_TYPE_TAG, data, hashCode)).info = commonSuperTypeIndex;
return commonSuperTypeIndex;
}
/**
* Adds the given type Symbol to {@link #typeTable}.
*
* @param entry a {@link Symbol#TYPE_TAG} or {@link Symbol#UNINITIALIZED_TYPE_TAG} type symbol.
* The index of this Symbol must be equal to the current value of {@link #typeCount}.
* @return the index in {@link #typeTable} where the given type was added, which is also equal to
* entry's index by hypothesis.
*/
private int addTypeInternal(final Entry entry) {
if (typeTable == null) {
typeTable = new Entry[16];
}
if (typeCount == typeTable.length) {
Entry[] newTypeTable = new Entry[2 * typeTable.length];
System.arraycopy(typeTable, 0, newTypeTable, 0, typeTable.length);
typeTable = newTypeTable;
}
typeTable[typeCount++] = entry;
return put(entry).index;
}
// -----------------------------------------------------------------------------------------------
// Static helper methods to compute hash codes.
// -----------------------------------------------------------------------------------------------
private static int hash(final int tag, final int value) {
return 0x7FFFFFFF & (tag + value);
}
private static int hash(final int tag, final long value) {
return 0x7FFFFFFF & (tag + (int) value + (int) (value >>> 32));
}
private static int hash(final int tag, final String value) {
return 0x7FFFFFFF & (tag + value.hashCode());
}
private static int hash(final int tag, final String value1, final int value2) {
return 0x7FFFFFFF & (tag + value1.hashCode() + value2);
}
private static int hash(final int tag, final String value1, final String value2) {
return 0x7FFFFFFF & (tag + value1.hashCode() * value2.hashCode());
}
private static int hash(
final int tag, final String value1, final String value2, final int value3) {
return 0x7FFFFFFF & (tag + value1.hashCode() * value2.hashCode() * (value3 + 1));
}
private static int hash(
final int tag, final String value1, final String value2, final String value3) {
return 0x7FFFFFFF & (tag + value1.hashCode() * value2.hashCode() * value3.hashCode());
}
private static int hash(
final int tag,
final String value1,
final String value2,
final String value3,
final int value4) {
return 0x7FFFFFFF & (tag + value1.hashCode() * value2.hashCode() * value3.hashCode() * value4);
}
/**
* An entry of a SymbolTable. This concrete and private subclass of {@link Symbol} adds two fields
* which are only used inside SymbolTable, to implement hash sets of symbols (in order to avoid
* duplicate symbols). See {@link #entries}.
*
* @author Eric Bruneton
*/
private static class Entry extends Symbol {
/** The hash code of this entry. */
final int hashCode;
/**
* Another entry (and so on recursively) having the same hash code (modulo the size of {@link
* #entries}) as this one.
*/
Entry next;
Entry(
final int index,
final int tag,
final String owner,
final String name,
final String value,
final long data,
final int hashCode) {
super(index, tag, owner, name, value, data);
this.hashCode = hashCode;
}
Entry(final int index, final int tag, final String value, final int hashCode) {
super(index, tag, /* owner = */ null, /* name = */ null, value, /* data = */ 0);
this.hashCode = hashCode;
}
Entry(final int index, final int tag, final String value, final long data, final int hashCode) {
super(index, tag, /* owner = */ null, /* name = */ null, value, data);
this.hashCode = hashCode;
}
Entry(
final int index, final int tag, final String name, final String value, final int hashCode) {
super(index, tag, /* owner = */ null, name, value, /* data = */ 0);
this.hashCode = hashCode;
}
Entry(final int index, final int tag, final long data, final int hashCode) {
super(index, tag, /* owner = */ null, /* name = */ null, /* value = */ null, data);
this.hashCode = hashCode;
}
}
}