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JMockit is a Java toolkit for automated developer testing. It contains mocking/faking APIs and a code coverage tool, supporting both JUnit and TestNG. The mocking APIs allow all kinds of Java code, without testability restrictions, to be tested in isolation from selected dependencies.

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/***
 * 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 mockit.external.asm;

import mockit.internal.util.*;
import static mockit.internal.util.ClassLoad.OBJECT;

/**
 * A {@link ClassVisitor} that generates classes in bytecode form. More
 * precisely this visitor generates a byte array conforming to the Java class
 * file format. It can be used alone, to generate a Java class "from scratch",
 * or with one or more {@link ClassReader ClassReader} and adapter class visitor
 * to generate a modified class from one or more existing Java classes.
 * 
 * @author Eric Bruneton
 */
public final class ClassWriter extends ClassVisitor {

    /**
     * Flag to automatically compute the maximum stack size and the maximum
     * number of local variables of methods. If this flag is set, then the
     * arguments of the {@link MethodVisitor#visitMaxs visitMaxs} method of the
     * {@link MethodVisitor} returned by the {@link #visitMethod visitMethod}
     * method will be ignored, and computed automatically from the signature and
     * the bytecode of each method.
     * 
     * @see #ClassWriter(int)
     */
    public static final int COMPUTE_MAXS = 1;

    /**
     * Flag to automatically compute the stack map frames of methods from
     * scratch. If this flag is set, then the calls to the
     * {@link MethodVisitor#visitFrame} method are ignored, and the stack map
     * frames are recomputed from the methods bytecode. The arguments of the
     * {@link MethodVisitor#visitMaxs visitMaxs} method are also ignored and
     * recomputed from the bytecode. In other words, computeFrames implies
     * computeMaxs.
     * 
     * @see #ClassWriter(int)
     */
    public static final int COMPUTE_FRAMES = 2;

    /**
     * Pseudo access flag to distinguish between the synthetic attribute and the
     * synthetic access flag.
     */
    static final int ACC_SYNTHETIC_ATTRIBUTE = 0x40000;

    /**
     * Factor to convert from ACC_SYNTHETIC_ATTRIBUTE to Opcode.ACC_SYNTHETIC.
     */
    static final int TO_ACC_SYNTHETIC = ACC_SYNTHETIC_ATTRIBUTE
            / Opcodes.ACC_SYNTHETIC;

    /**
     * The type of instructions without any argument.
     */
    static final int NOARG_INSN = 0;

    /**
     * The type of instructions with an signed byte argument.
     */
    static final int SBYTE_INSN = 1;

    /**
     * The type of instructions with an signed short argument.
     */
    static final int SHORT_INSN = 2;

    /**
     * The type of instructions with a local variable index argument.
     */
    static final int VAR_INSN = 3;

    /**
     * The type of instructions with an implicit local variable index argument.
     */
    static final int IMPLVAR_INSN = 4;

    /**
     * The type of instructions with a type descriptor argument.
     */
    static final int TYPE_INSN = 5;

    /**
     * The type of field and method invocations instructions.
     */
    static final int FIELDORMETH_INSN = 6;

    /**
     * The type of the INVOKEINTERFACE/INVOKEDYNAMIC instruction.
     */
    static final int ITFMETH_INSN = 7;

    /**
     * The type of the INVOKEDYNAMIC instruction.
     */
    static final int INDYMETH_INSN = 8;

    /**
     * The type of instructions with a 2 bytes bytecode offset label.
     */
    static final int LABEL_INSN = 9;

    /**
     * The type of instructions with a 4 bytes bytecode offset label.
     */
    static final int LABELW_INSN = 10;

    /**
     * The type of the LDC instruction.
     */
    static final int LDC_INSN = 11;

    /**
     * The type of the LDC_W and LDC2_W instructions.
     */
    static final int LDCW_INSN = 12;

    /**
     * The type of the IINC instruction.
     */
    static final int IINC_INSN = 13;

    /**
     * The type of the TABLESWITCH instruction.
     */
    static final int TABL_INSN = 14;

    /**
     * The type of the LOOKUPSWITCH instruction.
     */
    static final int LOOK_INSN = 15;

    /**
     * The type of the MULTIANEWARRAY instruction.
     */
    static final int MANA_INSN = 16;

    /**
     * The type of the WIDE instruction.
     */
    static final int WIDE_INSN = 17;

    /**
     * The instruction types of all JVM opcodes.
     */
    static final byte[] TYPE;

    /**
     * The type of CONSTANT_Class constant pool items.
     */
    static final int CLASS = 7;

    /**
     * The type of CONSTANT_Fieldref constant pool items.
     */
    static final int FIELD = 9;

    /**
     * The type of CONSTANT_Methodref constant pool items.
     */
    static final int METH = 10;

    /**
     * The type of CONSTANT_InterfaceMethodref constant pool items.
     */
    static final int IMETH = 11;

    /**
     * The type of CONSTANT_String constant pool items.
     */
    static final int STR = 8;

    /**
     * The type of CONSTANT_Integer constant pool items.
     */
    static final int INT = 3;

    /**
     * The type of CONSTANT_Float constant pool items.
     */
    static final int FLOAT = 4;

    /**
     * The type of CONSTANT_Long constant pool items.
     */
    static final int LONG = 5;

    /**
     * The type of CONSTANT_Double constant pool items.
     */
    static final int DOUBLE = 6;

    /**
     * The type of CONSTANT_NameAndType constant pool items.
     */
    static final int NAME_TYPE = 12;

    /**
     * The type of CONSTANT_Utf8 constant pool items.
     */
    static final int UTF8 = 1;

    /**
     * The type of CONSTANT_MethodType constant pool items.
     */
    static final int MTYPE = 16;

    /**
     * The type of CONSTANT_MethodHandle constant pool items.
     */
    static final int HANDLE = 15;

    /**
     * The type of CONSTANT_InvokeDynamic constant pool items.
     */
    static final int INDY = 18;

    /**
     * The base value for all CONSTANT_MethodHandle constant pool items.
     * Internally, ASM store the 9 variations of CONSTANT_MethodHandle into 9
     * different items.
     */
    static final int HANDLE_BASE = 20;

    /**
     * Normal type Item stored in the ClassWriter {@link ClassWriter#typeTable},
     * instead of the constant pool, in order to avoid clashes with normal
     * constant pool items in the ClassWriter constant pool's hash table.
     */
    static final int TYPE_NORMAL = 30;

    /**
     * Uninitialized type Item stored in the ClassWriter
     * {@link ClassWriter#typeTable}, instead of the constant pool, in order to
     * avoid clashes with normal constant pool items in the ClassWriter constant
     * pool's hash table.
     */
    static final int TYPE_UNINIT = 31;

    /**
     * Merged type Item stored in the ClassWriter {@link ClassWriter#typeTable},
     * instead of the constant pool, in order to avoid clashes with normal
     * constant pool items in the ClassWriter constant pool's hash table.
     */
    static final int TYPE_MERGED = 32;

    /**
     * The type of BootstrapMethods items. These items are stored in a special
     * class attribute named BootstrapMethods and not in the constant pool.
     */
    static final int BSM = 33;

    /**
     * The class reader from which this class writer was constructed, if any.
     */
    ClassReader cr;

    /**
     * Minor and major version numbers of the class to be generated.
     */
    int version;

    /**
     * Index of the next item to be added in the constant pool.
     */
    int index;

    /**
     * The constant pool of this class.
     */
    final ByteVector pool;

    /**
     * The constant pool's hash table data.
     */
    Item[] items;

    /**
     * The threshold of the constant pool's hash table.
     */
    int threshold;

    /**
     * A reusable key used to look for items in the {@link #items} hash table.
     */
    final Item key;

    /**
     * A reusable key used to look for items in the {@link #items} hash table.
     */
    final Item key2;

    /**
     * A reusable key used to look for items in the {@link #items} hash table.
     */
    final Item key3;

    /**
     * A reusable key used to look for items in the {@link #items} hash table.
     */
    final Item key4;

    /**
     * A 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 associates to each index i
     * the Item whose index is i. All Item objects stored in this array
     * are also stored in the {@link #items} hash table. These two arrays allow
     * to retrieve an Item from its index or, conversely, to get the index of an
     * Item from its value. Each Item stores an internal name in its
     * {@link Item#strVal1} field.
     */
    Item[] typeTable;

    /**
     * Number of elements in the {@link #typeTable} array.
     */
    private short typeCount;

    /**
     * The access flags of this class.
     */
    private int access;

    /**
     * The constant pool item that contains the internal name of this class.
     */
    private int name;

    /**
     * The internal name of this class.
     */
    String thisName;

    /**
     * The constant pool item that contains the signature of this class.
     */
    private int signature;

    /**
     * The constant pool item that contains the internal name of the super class
     * of this class.
     */
    private int superName;

    /**
     * Number of interfaces implemented or extended by this class or interface.
     */
    private int interfaceCount;

    /**
     * The interfaces implemented or extended by this class or interface. More
     * precisely, this array contains the indexes of the constant pool items
     * that contain the internal names of these interfaces.
     */
    private int[] interfaces;

    /**
     * The index of the constant pool item that contains the name of the source
     * file from which this class was compiled.
     */
    private int sourceFile;

    /**
     * The SourceDebug attribute of this class.
     */
    private ByteVector sourceDebug;

    /**
     * The constant pool item that contains the name of the enclosing class of
     * this class.
     */
    private int enclosingMethodOwner;

    /**
     * The constant pool item that contains the name and descriptor of the
     * enclosing method of this class.
     */
    private int enclosingMethod;

    /**
     * The runtime visible annotations of this class.
     */
    private AnnotationWriter anns;

    /**
     * The runtime invisible annotations of this class.
     */
    private AnnotationWriter ianns;

    /**
     * The runtime visible type annotations of this class.
     */
    private AnnotationWriter tanns;

    /**
     * The runtime invisible type annotations of this class.
     */
    private AnnotationWriter itanns;

    /**
     * The non standard attributes of this class.
     */
    private Attribute attrs;

    /**
     * The number of entries in the InnerClasses attribute.
     */
    private int innerClassesCount;

    /**
     * The InnerClasses attribute.
     */
    private ByteVector innerClasses;

    /**
     * The number of entries in the BootstrapMethods attribute.
     */
    int bootstrapMethodsCount;

    /**
     * The BootstrapMethods attribute.
     */
    ByteVector bootstrapMethods;

    /**
     * The fields of this class. These fields are stored in a linked list of
     * {@link FieldWriter} objects, linked to each other by their
     * {@link FieldWriter#fv} field. This field stores the first element of this
     * list.
     */
    FieldWriter firstField;

    /**
     * The fields of this class. These fields are stored in a linked list of
     * {@link FieldWriter} objects, linked to each other by their
     * {@link FieldWriter#fv} field. This field stores the last element of this
     * list.
     */
    FieldWriter lastField;

    /**
     * The methods of this class. These methods are stored in a linked list of
     * {@link MethodWriter} objects, linked to each other by their
     * {@link MethodWriter#mv} field. This field stores the first element of
     * this list.
     */
    MethodWriter firstMethod;

    /**
     * The methods of this class. These methods are stored in a linked list of
     * {@link MethodWriter} objects, linked to each other by their
     * {@link MethodWriter#mv} field. This field stores the last element of this
     * list.
     */
    MethodWriter lastMethod;

    /**
     * true if the maximum stack size and number of local variables
     * must be automatically computed.
     */
    private boolean computeMaxs;

    /**
     * true if the stack map frames must be recomputed from scratch.
     */
    private boolean computeFrames;

    /**
     * true if the stack map tables of this class are invalid. The
     * {@link MethodWriter#resizeInstructions} method cannot transform existing
     * stack map tables, and so produces potentially invalid classes when it is
     * executed. In this case the class is reread and rewritten with the
     * {@link #COMPUTE_FRAMES} option (the resizeInstructions method can resize
     * stack map tables when this option is used).
     */
    boolean invalidFrames;

    // ------------------------------------------------------------------------
    // Static initializer
    // ------------------------------------------------------------------------

    /**
     * Computes the instruction types of JVM opcodes.
     */
    static {
        int i;
        byte[] b = new byte[220];
        String s = "AAAAAAAAAAAAAAAABCLMMDDDDDEEEEEEEEEEEEEEEEEEEEAAAAAAAADD"
                + "DDDEEEEEEEEEEEEEEEEEEEEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
                + "AAAAAAAAAAAAAAAAANAAAAAAAAAAAAAAAAAAAAJJJJJJJJJJJJJJJJDOPAA"
                + "AAAAGGGGGGGHIFBFAAFFAARQJJKKJJJJJJJJJJJJJJJJJJ";
        for (i = 0; i < b.length; ++i) {
            b[i] = (byte) (s.charAt(i) - 'A');
        }
        TYPE = b;

        // code to generate the above string
        //
        // // SBYTE_INSN instructions
        // b[Constants.NEWARRAY] = SBYTE_INSN;
        // b[Constants.BIPUSH] = SBYTE_INSN;
        //
        // // SHORT_INSN instructions
        // b[Constants.SIPUSH] = SHORT_INSN;
        //
        // // (IMPL)VAR_INSN instructions
        // b[Constants.RET] = VAR_INSN;
        // for (i = Constants.ILOAD; i <= Constants.ALOAD; ++i) {
        // b[i] = VAR_INSN;
        // }
        // for (i = Constants.ISTORE; i <= Constants.ASTORE; ++i) {
        // b[i] = VAR_INSN;
        // }
        // for (i = 26; i <= 45; ++i) { // ILOAD_0 to ALOAD_3
        // b[i] = IMPLVAR_INSN;
        // }
        // for (i = 59; i <= 78; ++i) { // ISTORE_0 to ASTORE_3
        // b[i] = IMPLVAR_INSN;
        // }
        //
        // // TYPE_INSN instructions
        // b[Constants.NEW] = TYPE_INSN;
        // b[Constants.ANEWARRAY] = TYPE_INSN;
        // b[Constants.CHECKCAST] = TYPE_INSN;
        // b[Constants.INSTANCEOF] = TYPE_INSN;
        //
        // // (Set)FIELDORMETH_INSN instructions
        // for (i = Constants.GETSTATIC; i <= Constants.INVOKESTATIC; ++i) {
        // b[i] = FIELDORMETH_INSN;
        // }
        // b[Constants.INVOKEINTERFACE] = ITFMETH_INSN;
        // b[Constants.INVOKEDYNAMIC] = INDYMETH_INSN;
        //
        // // LABEL(W)_INSN instructions
        // for (i = Constants.IFEQ; i <= Constants.JSR; ++i) {
        // b[i] = LABEL_INSN;
        // }
        // b[Constants.IFNULL] = LABEL_INSN;
        // b[Constants.IFNONNULL] = LABEL_INSN;
        // b[200] = LABELW_INSN; // GOTO_W
        // b[201] = LABELW_INSN; // JSR_W
        // // temporary opcodes used internally by ASM - see Label and
        // MethodWriter
        // for (i = 202; i < 220; ++i) {
        // b[i] = LABEL_INSN;
        // }
        //
        // // LDC(_W) instructions
        // b[Constants.LDC] = LDC_INSN;
        // b[19] = LDCW_INSN; // LDC_W
        // b[20] = LDCW_INSN; // LDC2_W
        //
        // // special instructions
        // b[Constants.IINC] = IINC_INSN;
        // b[Constants.TABLESWITCH] = TABL_INSN;
        // b[Constants.LOOKUPSWITCH] = LOOK_INSN;
        // b[Constants.MULTIANEWARRAY] = MANA_INSN;
        // b[196] = WIDE_INSN; // WIDE
        //
        // for (i = 0; i < b.length; ++i) {
        // System.err.print((char)('A' + b[i]));
        // }
        // System.err.println();
    }

    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------

    /**
     * Constructs a new {@link ClassWriter} object.
     * 
     * @param flags
     *            option flags that can be used to modify the default behavior
     *            of this class. See {@link #COMPUTE_MAXS},
     *            {@link #COMPUTE_FRAMES}.
     */
    private ClassWriter(int flags)
    {
        index = 1;
        pool = new ByteVector();
        items = new Item[256];
        threshold = (int) (0.75d * items.length);
        key = new Item();
        key2 = new Item();
        key3 = new Item();
        key4 = new Item();
        this.computeMaxs = (flags & COMPUTE_MAXS) != 0;
        this.computeFrames = (flags & COMPUTE_FRAMES) != 0;
    }

    /**
     * Constructs a new {@link ClassWriter} object and enables optimizations for
     * "mostly add" bytecode transformations. These optimizations are the
     * following:
     * 
     * 
    *
  • The constant pool from the original class is copied as is in the new * class, which saves time. New constant pool entries will be added at the * end if necessary, but unused constant pool entries won't be * removed.
  • *
  • Methods that are not transformed are copied as is in the new class, * directly from the original class bytecode (i.e. without emitting visit * events for all the method instructions), which saves a lot of * time. Untransformed methods are detected by the fact that the * {@link ClassReader} receives {@link MethodVisitor} objects that come from * a {@link ClassWriter} (and not from any other {@link ClassVisitor} * instance).
  • *
* * @param classReader * the {@link ClassReader} used to read the original class. It * will be used to copy the entire constant pool from the * original class and also to copy other fragments of original * bytecode where applicable. * @param flags * option flags that can be used to modify the default behavior * of this class. These option flags do not affect methods * that are copied as is in the new class. This means that the * maximum stack size nor the stack frames will be computed for * these methods. See {@link #COMPUTE_MAXS}, * {@link #COMPUTE_FRAMES}. */ public ClassWriter(final ClassReader classReader, final int flags) { this(flags); classReader.copyPool(this); this.cr = classReader; } // ------------------------------------------------------------------------ // Implementation of the ClassVisitor abstract class // ------------------------------------------------------------------------ @Override public final void visit(final int version, final int access, final String name, final String signature, final String superName, final String[] interfaces) { this.version = version; this.access = access; this.name = newClass(name); thisName = name; if (ClassReader.SIGNATURES && signature != null) { this.signature = newUTF8(signature); } this.superName = superName == null ? 0 : newClass(superName); if (interfaces != null && interfaces.length > 0) { interfaceCount = interfaces.length; this.interfaces = new int[interfaceCount]; for (int i = 0; i < interfaceCount; ++i) { this.interfaces[i] = newClass(interfaces[i]); } } if (superName != null) { ClassLoad.addSuperClass(name, superName); } } @Override public final void visitSource(final String file, final String debug) { if (file != null) { sourceFile = newUTF8(file); } if (debug != null) { sourceDebug = new ByteVector().encodeUTF8(debug, 0, Integer.MAX_VALUE); } } @Override public final void visitOuterClass(final String owner, final String name, final String desc) { enclosingMethodOwner = newClass(owner); if (name != null && desc != null) { enclosingMethod = newNameType(name, desc); } } @Override public final AnnotationVisitor visitAnnotation(final String desc, final boolean visible) { if (!ClassReader.ANNOTATIONS) { return null; } ByteVector bv = new ByteVector(); // write type, and reserve space for values count bv.putShort(newUTF8(desc)).putShort(0); AnnotationWriter aw = new AnnotationWriter(this, true, bv, bv, 2); if (visible) { aw.next = anns; anns = aw; } else { aw.next = ianns; ianns = aw; } return aw; } @Override public final AnnotationVisitor visitTypeAnnotation(int typeRef, TypePath typePath, final String desc, final boolean visible) { if (!ClassReader.ANNOTATIONS) { return null; } ByteVector bv = new ByteVector(); // write target_type and target_info AnnotationWriter.putTarget(typeRef, typePath, bv); // write type, and reserve space for values count bv.putShort(newUTF8(desc)).putShort(0); AnnotationWriter aw = new AnnotationWriter(this, true, bv, bv, bv.length - 2); if (visible) { aw.next = tanns; tanns = aw; } else { aw.next = itanns; itanns = aw; } return aw; } @Override public final void visitAttribute(final Attribute attr) { attr.next = attrs; attrs = attr; } @Override public final void visitInnerClass(final String name, final String outerName, final String innerName, final int access) { if (innerClasses == null) { innerClasses = new ByteVector(); } // Sec. 4.7.6 of the JVMS states "Every CONSTANT_Class_info entry in the // constant_pool table which represents a class or interface C that is // not a package member must have exactly one corresponding entry in the // classes array". To avoid duplicates we keep track in the intVal field // of the Item of each CONSTANT_Class_info entry C whether an inner // class entry has already been added for C (this field is unused for // class entries, and changing its value does not change the hashcode // and equality tests). If so we store the index of this inner class // entry (plus one) in intVal. This hack allows duplicate detection in // O(1) time. Item nameItem = newClassItem(name); if (nameItem.intVal == 0) { ++innerClassesCount; innerClasses.putShort(nameItem.index); innerClasses.putShort(outerName == null ? 0 : newClass(outerName)); innerClasses.putShort(innerName == null ? 0 : newUTF8(innerName)); innerClasses.putShort(access); nameItem.intVal = innerClassesCount; } else { // Compare the inner classes entry nameItem.intVal - 1 with the // arguments of this method and throw an exception if there is a // difference? } } @Override public final FieldVisitor visitField(final int access, final String name, final String desc, final String signature, final Object value) { return new FieldWriter(this, access, name, desc, signature, value); } @Override public final MethodWriter visitMethod(final int access, final String name, final String desc, final String signature, final String[] exceptions) { return new MethodWriter(this, access, name, desc, signature, exceptions, computeMaxs, computeFrames); } @Override public final void visitEnd() { } // ------------------------------------------------------------------------ // Other public methods // ------------------------------------------------------------------------ /** * Returns the bytecode of the class that was build with this class writer. * * @return the bytecode of the class that was build with this class writer. */ @Override public byte[] toByteArray() { if (index > 0xFFFF) { throw new RuntimeException("Class file too large!"); } // computes the real size of the bytecode of this class int size = 24 + 2 * interfaceCount; int nbFields = 0; FieldWriter fb = firstField; while (fb != null) { ++nbFields; size += fb.getSize(); fb = (FieldWriter) fb.fv; } int nbMethods = 0; MethodWriter mb = firstMethod; while (mb != null) { ++nbMethods; size += mb.getSize(); mb = (MethodWriter) mb.mv; } int attributeCount = 0; if (bootstrapMethods != null) { // we put it as first attribute in order to improve a bit // ClassReader.copyBootstrapMethods ++attributeCount; size += 8 + bootstrapMethods.length; newUTF8("BootstrapMethods"); } if (ClassReader.SIGNATURES && signature != 0) { ++attributeCount; size += 8; newUTF8("Signature"); } if (sourceFile != 0) { ++attributeCount; size += 8; newUTF8("SourceFile"); } if (sourceDebug != null) { ++attributeCount; size += sourceDebug.length + 6; newUTF8("SourceDebugExtension"); } if (enclosingMethodOwner != 0) { ++attributeCount; size += 10; newUTF8("EnclosingMethod"); } if ((access & Opcodes.ACC_DEPRECATED) != 0) { ++attributeCount; size += 6; newUTF8("Deprecated"); } if ((access & Opcodes.ACC_SYNTHETIC) != 0) { if ((version & 0xFFFF) < Opcodes.V1_5 || (access & ACC_SYNTHETIC_ATTRIBUTE) != 0) { ++attributeCount; size += 6; newUTF8("Synthetic"); } } if (innerClasses != null) { ++attributeCount; size += 8 + innerClasses.length; newUTF8("InnerClasses"); } if (ClassReader.ANNOTATIONS && anns != null) { ++attributeCount; size += 8 + anns.getSize(); newUTF8("RuntimeVisibleAnnotations"); } if (ClassReader.ANNOTATIONS && ianns != null) { ++attributeCount; size += 8 + ianns.getSize(); newUTF8("RuntimeInvisibleAnnotations"); } if (ClassReader.ANNOTATIONS && tanns != null) { ++attributeCount; size += 8 + tanns.getSize(); newUTF8("RuntimeVisibleTypeAnnotations"); } if (ClassReader.ANNOTATIONS && itanns != null) { ++attributeCount; size += 8 + itanns.getSize(); newUTF8("RuntimeInvisibleTypeAnnotations"); } if (attrs != null) { attributeCount += attrs.getCount(); size += attrs.getSize(this); } size += pool.length; // allocates a byte vector of this size, in order to avoid unnecessary // arraycopy operations in the ByteVector.enlarge() method ByteVector out = new ByteVector(size); out.putInt(0xCAFEBABE).putInt(version); out.putShort(index).putByteArray(pool.data, 0, pool.length); int mask = Opcodes.ACC_DEPRECATED | ACC_SYNTHETIC_ATTRIBUTE | ((access & ACC_SYNTHETIC_ATTRIBUTE) / TO_ACC_SYNTHETIC); out.putShort(access & ~mask).putShort(name).putShort(superName); out.putShort(interfaceCount); for (int i = 0; i < interfaceCount; ++i) { out.putShort(interfaces[i]); } out.putShort(nbFields); fb = firstField; while (fb != null) { fb.put(out); fb = (FieldWriter) fb.fv; } out.putShort(nbMethods); mb = firstMethod; while (mb != null) { mb.put(out); mb = (MethodWriter) mb.mv; } out.putShort(attributeCount); if (bootstrapMethods != null) { out.putShort(newUTF8("BootstrapMethods")); out.putInt(bootstrapMethods.length + 2).putShort( bootstrapMethodsCount); out.putByteArray(bootstrapMethods.data, 0, bootstrapMethods.length); } if (ClassReader.SIGNATURES && signature != 0) { out.putShort(newUTF8("Signature")).putInt(2).putShort(signature); } if (sourceFile != 0) { out.putShort(newUTF8("SourceFile")).putInt(2).putShort(sourceFile); } if (sourceDebug != null) { int len = sourceDebug.length; out.putShort(newUTF8("SourceDebugExtension")).putInt(len); out.putByteArray(sourceDebug.data, 0, len); } if (enclosingMethodOwner != 0) { out.putShort(newUTF8("EnclosingMethod")).putInt(4); out.putShort(enclosingMethodOwner).putShort(enclosingMethod); } if ((access & Opcodes.ACC_DEPRECATED) != 0) { out.putShort(newUTF8("Deprecated")).putInt(0); } if ((access & Opcodes.ACC_SYNTHETIC) != 0) { if ((version & 0xFFFF) < Opcodes.V1_5 || (access & ACC_SYNTHETIC_ATTRIBUTE) != 0) { out.putShort(newUTF8("Synthetic")).putInt(0); } } if (innerClasses != null) { out.putShort(newUTF8("InnerClasses")); out.putInt(innerClasses.length + 2).putShort(innerClassesCount); out.putByteArray(innerClasses.data, 0, innerClasses.length); } if (ClassReader.ANNOTATIONS && anns != null) { out.putShort(newUTF8("RuntimeVisibleAnnotations")); anns.put(out); } if (ClassReader.ANNOTATIONS && ianns != null) { out.putShort(newUTF8("RuntimeInvisibleAnnotations")); ianns.put(out); } if (ClassReader.ANNOTATIONS && tanns != null) { out.putShort(newUTF8("RuntimeVisibleTypeAnnotations")); tanns.put(out); } if (ClassReader.ANNOTATIONS && itanns != null) { out.putShort(newUTF8("RuntimeInvisibleTypeAnnotations")); itanns.put(out); } if (attrs != null) { attrs.put(this, out); } if (invalidFrames) { anns = null; ianns = null; attrs = null; innerClassesCount = 0; innerClasses = null; bootstrapMethodsCount = 0; bootstrapMethods = null; firstField = null; lastField = null; firstMethod = null; lastMethod = null; computeMaxs = false; computeFrames = true; invalidFrames = false; new ClassReader(out.data).accept(this, ClassReader.SKIP_FRAMES); return toByteArray(); } return out.data; } // ------------------------------------------------------------------------ // Utility methods: constant pool management // ------------------------------------------------------------------------ /** * Adds a number or string constant to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * * @param cst * the value of the constant to be added to the constant pool. * This parameter must be an {@link Integer}, a {@link Float}, a * {@link Long}, a {@link Double}, a {@link String} or a * {@link Type}. * @return a new or already existing constant item with the given value. */ Item newConstItem(final Object cst) { if (cst instanceof Integer) { int val = ((Integer) cst).intValue(); return newInteger(val); } else if (cst instanceof Byte) { int val = ((Byte) cst).intValue(); return newInteger(val); } else if (cst instanceof Character) { int val = ((Character) cst).charValue(); return newInteger(val); } else if (cst instanceof Short) { int val = ((Short) cst).intValue(); return newInteger(val); } else if (cst instanceof Boolean) { int val = ((Boolean) cst).booleanValue() ? 1 : 0; return newInteger(val); } else if (cst instanceof Float) { float val = ((Float) cst).floatValue(); return newFloat(val); } else if (cst instanceof Long) { long val = ((Long) cst).longValue(); return newLong(val); } else if (cst instanceof Double) { double val = ((Double) cst).doubleValue(); return newDouble(val); } else if (cst instanceof String) { return newString((String) cst); } else if (cst instanceof Type) { Type t = (Type) cst; int s = t.getSort(); if (s == Type.OBJECT) { return newClassItem(t.getInternalName()); } else if (s == Type.METHOD) { return newMethodTypeItem(t.getDescriptor()); } else { // s == primitive type or array return newClassItem(t.getDescriptor()); } } else if (cst instanceof Handle) { Handle h = (Handle) cst; return newHandleItem(h.tag, h.owner, h.name, h.desc); } else { throw new IllegalArgumentException("value " + cst); } } /** * Adds a number or string constant to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param cst * the value of the constant to be added to the constant pool. * This parameter must be an {@link Integer}, a {@link Float}, a * {@link Long}, a {@link Double} or a {@link String}. * @return the index of a new or already existing constant item with the * given value. */ public int newConst(final Object cst) { return newConstItem(cst).index; } /** * Adds an UTF8 string to the constant pool of the class being build. Does * nothing if the constant pool already contains a similar item. This * method is intended for {@link Attribute} sub classes, and is normally not * needed by class generators or adapters. * * @param value * the String value. * @return the index of a new or already existing UTF8 item. */ public int newUTF8(final String value) { key.set(UTF8, value, null, null); Item result = get(key); if (result == null) { pool.putByte(UTF8).putUTF8(value); result = new Item(index++, key); put(result); } return result.index; } /** * Adds a class reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param value * the internal name of the class. * @return a new or already existing class reference item. */ Item newClassItem(final String value) { key2.set(CLASS, value, null, null); Item result = get(key2); if (result == null) { pool.put12(CLASS, newUTF8(value)); result = new Item(index++, key2); put(result); } return result; } /** * Adds a class reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param value * the internal name of the class. * @return the index of a new or already existing class reference item. */ public int newClass(final String value) { return newClassItem(value).index; } /** * Adds a method type reference to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param methodDesc * method descriptor of the method type. * @return a new or already existing method type reference item. */ Item newMethodTypeItem(final String methodDesc) { key2.set(MTYPE, methodDesc, null, null); Item result = get(key2); if (result == null) { pool.put12(MTYPE, newUTF8(methodDesc)); result = new Item(index++, key2); put(result); } return result; } /** * Adds a method type reference to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param methodDesc * method descriptor of the method type. * @return the index of a new or already existing method type reference * item. */ public int newMethodType(final String methodDesc) { return newMethodTypeItem(methodDesc).index; } /** * Adds a handle to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. This method is * intended for {@link Attribute} sub classes, and is normally not needed by * class generators or adapters. * * @param tag * the kind of this handle. Must be {@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 the field or method owner class. * @param name * the name of the field or method. * @param desc * the descriptor of the field or method. * @return a new or an already existing method type reference item. */ Item newHandleItem(final int tag, final String owner, final String name, final String desc) { key4.set(HANDLE_BASE + tag, owner, name, desc); Item result = get(key4); if (result == null) { if (tag <= Opcodes.H_PUTSTATIC) { put112(HANDLE, tag, newField(owner, name, desc)); } else { put112(HANDLE, tag, newMethod(owner, name, desc, tag == Opcodes.H_INVOKEINTERFACE)); } result = new Item(index++, key4); put(result); } return result; } /** * Adds a handle to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. This method is * intended for {@link Attribute} sub classes, and is normally not needed by * class generators or adapters. * * @param tag * the kind of this handle. Must be {@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 the field or method owner class. * @param name * the name of the field or method. * @param desc * the descriptor of the field or method. * @return the index of a new or already existing method type reference * item. */ public int newHandle(final int tag, final String owner, final String name, final String desc) { return newHandleItem(tag, owner, name, desc).index; } /** * Adds an invokedynamic reference to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param name * name of the invoked method. * @param desc * descriptor of the invoke method. * @param bsm * the bootstrap method. * @param bsmArgs * the bootstrap method constant arguments. * * @return a new or an already existing invokedynamic type reference item. */ Item newInvokeDynamicItem(final String name, final String desc, final Handle bsm, final Object... bsmArgs) { // cache for performance ByteVector bootstrapMethods = this.bootstrapMethods; if (bootstrapMethods == null) { bootstrapMethods = this.bootstrapMethods = new ByteVector(); } int position = bootstrapMethods.length; // record current position int hashCode = bsm.hashCode(); bootstrapMethods.putShort(newHandle(bsm.tag, bsm.owner, bsm.name, bsm.desc)); int argsLength = bsmArgs.length; bootstrapMethods.putShort(argsLength); for (int i = 0; i < argsLength; i++) { Object bsmArg = bsmArgs[i]; hashCode ^= bsmArg.hashCode(); bootstrapMethods.putShort(newConst(bsmArg)); } byte[] data = bootstrapMethods.data; int length = (1 + 1 + argsLength) << 1; // (bsm + argCount + arguments) hashCode &= 0x7FFFFFFF; Item result = items[hashCode % items.length]; loop: while (result != null) { if (result.type != BSM || result.hashCode != hashCode) { result = result.next; continue; } // because the data encode the size of the argument // we don't need to test if these size are equals int resultPosition = result.intVal; for (int p = 0; p < length; p++) { if (data[position + p] != data[resultPosition + p]) { result = result.next; continue loop; } } break; } int bootstrapMethodIndex; if (result != null) { bootstrapMethodIndex = result.index; bootstrapMethods.length = position; // revert to old position } else { bootstrapMethodIndex = bootstrapMethodsCount++; result = new Item(bootstrapMethodIndex); result.set(position, hashCode); put(result); } // now, create the InvokeDynamic constant key3.set(name, desc, bootstrapMethodIndex); result = get(key3); if (result == null) { put122(INDY, bootstrapMethodIndex, newNameType(name, desc)); result = new Item(index++, key3); put(result); } return result; } /** * Adds an invokedynamic reference to the constant pool of the class being * build. Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param name * name of the invoked method. * @param desc * descriptor of the invoke method. * @param bsm * the bootstrap method. * @param bsmArgs * the bootstrap method constant arguments. * * @return the index of a new or already existing invokedynamic reference * item. */ public int newInvokeDynamic(final String name, final String desc, final Handle bsm, final Object... bsmArgs) { return newInvokeDynamicItem(name, desc, bsm, bsmArgs).index; } /** * Adds a field reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * * @param owner * the internal name of the field's owner class. * @param name * the field's name. * @param desc * the field's descriptor. * @return a new or already existing field reference item. */ Item newFieldItem(final String owner, final String name, final String desc) { key3.set(FIELD, owner, name, desc); Item result = get(key3); if (result == null) { put122(FIELD, newClass(owner), newNameType(name, desc)); result = new Item(index++, key3); put(result); } return result; } /** * Adds a field reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param owner * the internal name of the field's owner class. * @param name * the field's name. * @param desc * the field's descriptor. * @return the index of a new or already existing field reference item. */ public int newField(final String owner, final String name, final String desc) { return newFieldItem(owner, name, desc).index; } /** * Adds a method reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * * @param owner * the internal name of the method's owner class. * @param name * the method's name. * @param desc * the method's descriptor. * @param itf * true if owner is an interface. * @return a new or already existing method reference item. */ Item newMethodItem(final String owner, final String name, final String desc, final boolean itf) { int type = itf ? IMETH : METH; key3.set(type, owner, name, desc); Item result = get(key3); if (result == null) { put122(type, newClass(owner), newNameType(name, desc)); result = new Item(index++, key3); put(result); } return result; } /** * Adds a method reference to the constant pool of the class being build. * Does nothing if the constant pool already contains a similar item. * This method is intended for {@link Attribute} sub classes, and is * normally not needed by class generators or adapters. * * @param owner * the internal name of the method's owner class. * @param name * the method's name. * @param desc * the method's descriptor. * @param itf * true if owner is an interface. * @return the index of a new or already existing method reference item. */ public int newMethod(final String owner, final String name, final String desc, final boolean itf) { return newMethodItem(owner, name, desc, itf).index; } /** * Adds an integer to the constant pool of the class being build. Does * nothing if the constant pool already contains a similar item. * * @param value * the int value. * @return a new or already existing int item. */ Item newInteger(final int value) { key.set(value); Item result = get(key); if (result == null) { pool.putByte(INT).putInt(value); result = new Item(index++, key); put(result); } return result; } /** * Adds a float to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. * * @param value * the float value. * @return a new or already existing float item. */ Item newFloat(final float value) { key.set(value); Item result = get(key); if (result == null) { pool.putByte(FLOAT).putInt(key.intVal); result = new Item(index++, key); put(result); } return result; } /** * Adds a long to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. * * @param value * the long value. * @return a new or already existing long item. */ Item newLong(final long value) { key.set(value); Item result = get(key); if (result == null) { pool.putByte(LONG).putLong(value); result = new Item(index, key); index += 2; put(result); } return result; } /** * Adds a double to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. * * @param value * the double value. * @return a new or already existing double item. */ Item newDouble(final double value) { key.set(value); Item result = get(key); if (result == null) { pool.putByte(DOUBLE).putLong(key.longVal); result = new Item(index, key); index += 2; put(result); } return result; } /** * Adds a string to the constant pool of the class being build. Does nothing * if the constant pool already contains a similar item. * * @param value * the String value. * @return a new or already existing string item. */ private Item newString(final String value) { key2.set(STR, value, null, null); Item result = get(key2); if (result == null) { pool.put12(STR, newUTF8(value)); result = new Item(index++, key2); put(result); } return result; } /** * Adds a name and type to the constant pool of the class being build. Does * nothing if the constant pool already contains a similar item. This * method is intended for {@link Attribute} sub classes, and is normally not * needed by class generators or adapters. * * @param name * a name. * @param desc * a type descriptor. * @return the index of a new or already existing name and type item. */ public int newNameType(final String name, final String desc) { return newNameTypeItem(name, desc).index; } /** * Adds a name and type to the constant pool of the class being build. Does * nothing if the constant pool already contains a similar item. * * @param name * a name. * @param desc * a type descriptor. * @return a new or already existing name and type item. */ Item newNameTypeItem(final String name, final String desc) { key2.set(NAME_TYPE, name, desc, null); Item result = get(key2); if (result == null) { put122(NAME_TYPE, newUTF8(name), newUTF8(desc)); result = new Item(index++, key2); put(result); } return result; } /** * Adds the given internal name to {@link #typeTable} and returns its index. * Does nothing if the type table already contains this internal name. * * @param type * the internal name to be added to the type table. * @return the index of this internal name in the type table. */ int addType(final String type) { key.set(TYPE_NORMAL, type, null, null); Item result = get(key); if (result == null) { result = addType(key); } return result.index; } /** * Adds the given "uninitialized" type to {@link #typeTable} and returns its * index. This method is used for UNINITIALIZED types, made of an internal * name and a bytecode offset. * * @param type * the internal name to be added to the type table. * @param offset * the bytecode offset of the NEW instruction that created this * UNINITIALIZED type value. * @return the index of this internal name in the type table. */ int addUninitializedType(final String type, final int offset) { key.type = TYPE_UNINIT; key.intVal = offset; key.strVal1 = type; key.hashCode = 0x7FFFFFFF & (TYPE_UNINIT + type.hashCode() + offset); Item result = get(key); if (result == null) { result = addType(key); } return result.index; } /** * Adds the given Item to {@link #typeTable}. * * @param item * the value to be added to the type table. * @return the added Item, which a new Item instance with the same value as * the given Item. */ private Item addType(final Item item) { ++typeCount; Item result = new Item(typeCount, key); put(result); if (typeTable == null) { typeTable = new Item[16]; } if (typeCount == typeTable.length) { Item[] newTable = new Item[2 * typeTable.length]; System.arraycopy(typeTable, 0, newTable, 0, typeTable.length); typeTable = newTable; } typeTable[typeCount] = result; return result; } /** * Returns the index of the common super type of the two given types. This * method calls {@link #getCommonSuperClass} and caches the result in the * {@link #items} hash table to speedup future calls with the same * parameters. * * @param type1 * index of an internal name in {@link #typeTable}. * @param type2 * index of an internal name in {@link #typeTable}. * @return the index of the common super type of the two given types. */ int getMergedType(final int type1, final int type2) { key2.type = TYPE_MERGED; key2.longVal = type1 | (((long) type2) << 32); key2.hashCode = 0x7FFFFFFF & (TYPE_MERGED + type1 + type2); Item result = get(key2); if (result == null) { String t = typeTable[type1].strVal1; String u = typeTable[type2].strVal1; key2.intVal = addType(getCommonSuperClass(t, u)); result = new Item((short) 0, key2); put(result); } return result.intVal; } /** * Returns the common super type of the two given types. The default * implementation of this method loads the two given classes and uses * the java.lang.Class methods to find the common super class. It can be * overridden to compute this common super type in other ways, in particular * without actually loading any class, or to take into account the class * that is currently being generated by this ClassWriter, which can of * course not be loaded since it is under construction. * * @param type1 * the internal name of a class. * @param type2 * the internal name of another class. * @return the internal name of the common super class of the two given * classes. */ private String getCommonSuperClass(final String type1, final String type2) { // Reimplemented to avoid "duplicate class definition" errors. String class1 = type1; String class2 = type2; while (true) { if (OBJECT.equals(class1) || OBJECT.equals(class2)) { return OBJECT; } String superClass = ClassLoad.whichIsSuperClass(class1, class2); if (superClass != null) { return superClass; } class1 = ClassLoad.getSuperClass(class1); class2 = ClassLoad.getSuperClass(class2); if (class1.equals(class2)) { return class1; } } } /** * Returns the constant pool's hash table item which is equal to the given * item. * * @param key * a constant pool item. * @return the constant pool's hash table item which is equal to the given * item, or null if there is no such item. */ private Item get(final Item key) { Item i = items[key.hashCode % items.length]; while (i != null && (i.type != key.type || !key.isEqualTo(i))) { i = i.next; } return i; } /** * Puts the given item in the constant pool's hash table. The hash table * must not already contains this item. * * @param i * the item to be added to the constant pool's hash table. */ private void put(final Item i) { if (index + typeCount > threshold) { int ll = items.length; int nl = ll * 2 + 1; Item[] newItems = new Item[nl]; for (int l = ll - 1; l >= 0; --l) { Item j = items[l]; while (j != null) { int index = j.hashCode % newItems.length; Item k = j.next; j.next = newItems[index]; newItems[index] = j; j = k; } } items = newItems; threshold = (int) (nl * 0.75); } int index = i.hashCode % items.length; i.next = items[index]; items[index] = i; } /** * Puts one byte and two shorts into the constant pool. * * @param b * a byte. * @param s1 * a short. * @param s2 * another short. */ private void put122(final int b, final int s1, final int s2) { pool.put12(b, s1).putShort(s2); } /** * Puts two bytes and one short into the constant pool. * * @param b1 * a byte. * @param b2 * another byte. * @param s * a short. */ private void put112(final int b1, final int b2, final int s) { pool.put11(b1, b2).putShort(s); } public ClassWriter(final ClassReader classReader) { this(classReader.getVersion() >= Opcodes.V1_7 ? COMPUTE_FRAMES : COMPUTE_MAXS); classReader.copyPool(this); this.cr = classReader; } }




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