diff options
Diffstat (limited to 'asm/src/main/java/org/objectweb/asm/SymbolTable.java')
| -rw-r--r-- | asm/src/main/java/org/objectweb/asm/SymbolTable.java | 1322 |
1 files changed, 1322 insertions, 0 deletions
diff --git a/asm/src/main/java/org/objectweb/asm/SymbolTable.java b/asm/src/main/java/org/objectweb/asm/SymbolTable.java new file mode 100644 index 00000000..a2f26f18 --- /dev/null +++ b/asm/src/main/java/org/objectweb/asm/SymbolTable.java @@ -0,0 +1,1322 @@ +// 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.objectweb.asm; + +/** + * The constant pool entries, the BootstrapMethods attribute entries and the (ASM specific) type + * table entries of a class. + * + * @author Eric Bruneton + * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.4">JVMS + * 4.4</a> + * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.23">JVMS + * 4.7.23</a> + */ +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 <i>not</i> 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 <i>not</i> 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.classFileBuffer; + 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.classFileBuffer; + 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 <i>not</i> 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 <i>not</i> check + * whether {@link #entries} already contains a similar entry or not, and does <i>not</i> 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. + int numBootstrapArguments = bootstrapMethodArguments.length; + int[] bootstrapMethodArgumentIndexes = new int[numBootstrapArguments]; + for (int i = 0; i < numBootstrapArguments; i++) { + bootstrapMethodArgumentIndexes[i] = addConstant(bootstrapMethodArguments[i]).index; + } + + // 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); + + bootstrapMethodsAttribute.putShort(numBootstrapArguments); + for (int i = 0; i < numBootstrapArguments; i++) { + bootstrapMethodsAttribute.putShort(bootstrapMethodArgumentIndexes[i]); + } + + // 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) { + long data = + typeTableIndex1 < typeTableIndex2 + ? typeTableIndex1 | (((long) typeTableIndex2) << 32) + : typeTableIndex2 | (((long) typeTableIndex1) << 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; + } + } +} |