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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package sun.invoke.util;

public enum Wrapper {
    //        wrapperType      simple     primitiveType  simple     char  emptyArray     format
    BOOLEAN(  Boolean.class,   "Boolean", boolean.class, "boolean", 'Z', new boolean[0], Format.unsigned( 1)),
    // These must be in the order defined for widening primitive conversions in JLS 5.1.2
    // Avoid boxing integral types here to defer initialization of internal caches
    BYTE   (     Byte.class,      "Byte",    byte.class,    "byte", 'B', new    byte[0], Format.signed(   8)),
    SHORT  (    Short.class,     "Short",   short.class,   "short", 'S', new   short[0], Format.signed(  16)),
    CHAR   (Character.class, "Character",    char.class,    "char", 'C', new    char[0], Format.unsigned(16)),
    INT    (  Integer.class,   "Integer",     int.class,     "int", 'I', new     int[0], Format.signed(  32)),
    LONG   (     Long.class,      "Long",    long.class,    "long", 'J', new    long[0], Format.signed(  64)),
    FLOAT  (    Float.class,     "Float",   float.class,   "float", 'F', new   float[0], Format.floating(32)),
    DOUBLE (   Double.class,    "Double",  double.class,  "double", 'D', new  double[0], Format.floating(64)),
    OBJECT (   Object.class,    "Object",  Object.class,  "Object", 'L', new  Object[0], Format.other(    1)),
    // VOID must be the last type, since it is "assignable" from any other type:
    VOID   (     Void.class,      "Void",    void.class,    "void", 'V',           null, Format.other(    0)),
    ;

    public static final int COUNT = 10;

    private final Class wrapperType;
    private final Class primitiveType;
    private final char     basicTypeChar;
    private final String   basicTypeString;
    private final Object   emptyArray;
    private final int      format;
    private final String   wrapperSimpleName;
    private final String   primitiveSimpleName;

    private Wrapper(Class wtype, String wtypeName, Class ptype, String ptypeName, char tchar, Object emptyArray, int format) {
        this.wrapperType = wtype;
        this.primitiveType = ptype;
        this.basicTypeChar = tchar;
        this.basicTypeString = String.valueOf(this.basicTypeChar);
        this.emptyArray = emptyArray;
        this.format = format;
        this.wrapperSimpleName = wtypeName;
        this.primitiveSimpleName = ptypeName;
    }

    /** For debugging, give the details of this wrapper. */
    public String detailString() {
        return wrapperSimpleName+
                java.util.Arrays.asList(wrapperType, primitiveType,
                basicTypeChar, zero(),
                "0x"+Integer.toHexString(format));
    }

    private abstract static class Format {
        static final int SLOT_SHIFT = 0, SIZE_SHIFT = 2, KIND_SHIFT = 12;
        static final int
                SIGNED   = (-1) << KIND_SHIFT,
                UNSIGNED = 0    << KIND_SHIFT,
                FLOATING = 1    << KIND_SHIFT;
        static final int
                SLOT_MASK = ((1<<(SIZE_SHIFT-SLOT_SHIFT))-1),
                SIZE_MASK = ((1<<(KIND_SHIFT-SIZE_SHIFT))-1);
        static int format(int kind, int size, int slots) {
            assert(((kind >> KIND_SHIFT) << KIND_SHIFT) == kind);
            assert((size & (size-1)) == 0); // power of two
            assert((kind == SIGNED)   ? (size > 0) :
                   (kind == UNSIGNED) ? (size > 0) :
                   (kind == FLOATING) ? (size == 32 || size == 64)  :
                   false);
            assert((slots == 2) ? (size == 64) :
                   (slots == 1) ? (size <= 32) :
                   false);
            return kind | (size << SIZE_SHIFT) | (slots << SLOT_SHIFT);
        }
        static final int
                INT      = SIGNED   | (32 << SIZE_SHIFT) | (1 << SLOT_SHIFT),
                SHORT    = SIGNED   | (16 << SIZE_SHIFT) | (1 << SLOT_SHIFT),
                BOOLEAN  = UNSIGNED | (1  << SIZE_SHIFT) | (1 << SLOT_SHIFT),
                CHAR     = UNSIGNED | (16 << SIZE_SHIFT) | (1 << SLOT_SHIFT),
                FLOAT    = FLOATING | (32 << SIZE_SHIFT) | (1 << SLOT_SHIFT),
                VOID     = UNSIGNED | (0  << SIZE_SHIFT) | (0 << SLOT_SHIFT),
                NUM_MASK = (-1) << SIZE_SHIFT;
        static int signed(int size)   { return format(SIGNED,   size, (size > 32 ? 2 : 1)); }
        static int unsigned(int size) { return format(UNSIGNED, size, (size > 32 ? 2 : 1)); }
        static int floating(int size) { return format(FLOATING, size, (size > 32 ? 2 : 1)); }
        static int other(int slots)   { return slots << SLOT_SHIFT; }
    }

    /// format queries:

    /** How many bits are in the wrapped value?  Returns 0 for OBJECT or VOID. */
    public int     bitWidth()      { return (format >> Format.SIZE_SHIFT) & Format.SIZE_MASK; }
    /** How many JVM stack slots occupied by the wrapped value?  Returns 0 for VOID. */
    public int     stackSlots()    { return (format >> Format.SLOT_SHIFT) & Format.SLOT_MASK; }
    /** Does the wrapped value occupy a single JVM stack slot? */
    public boolean isSingleWord()  { return (format & (1 << Format.SLOT_SHIFT)) != 0; }
    /** Does the wrapped value occupy two JVM stack slots? */
    public boolean isDoubleWord()  { return (format & (2 << Format.SLOT_SHIFT)) != 0; }
    /** Is the wrapped type numeric (not void or object)? */
    public boolean isNumeric()     { return (format & Format.NUM_MASK) != 0; }
    /** Is the wrapped type a primitive other than float, double, or void? */
    public boolean isIntegral()    { return isNumeric() && format < Format.FLOAT; }
    /** Is the wrapped type one of int, boolean, byte, char, or short? */
    public boolean isSubwordOrInt() { return isIntegral() && isSingleWord(); }
    /* Is the wrapped value a signed integral type (one of byte, short, int, or long)? */
    public boolean isSigned()      { return format < Format.VOID; }
    /* Is the wrapped value an unsigned integral type (one of boolean or char)? */
    public boolean isUnsigned()    { return format >= Format.BOOLEAN && format < Format.FLOAT; }
    /** Is the wrapped type either float or double? */
    public boolean isFloating()    { return format >= Format.FLOAT; }
    /** Is the wrapped type either void or a reference? */
    public boolean isOther()       { return (format & ~Format.SLOT_MASK) == 0; }

    /** Does the JLS 5.1.2 allow a variable of this wrapper's
     *  primitive type to be assigned from a value of the given wrapper's primitive type?
     *  Cases:
     *  
    *
  • unboxing followed by widening primitive conversion *
  • any type converted to {@code void} (i.e., dropping a method call's value) *
  • boxing conversion followed by widening reference conversion to {@code Object} *
* These are the cases allowed by MethodHandle.asType. */ public boolean isConvertibleFrom(Wrapper source) { if (this == source) return true; if (this.compareTo(source) < 0) { // At best, this is a narrowing conversion. return false; } // All conversions are allowed in the enum order between floats and signed ints. // First detect non-signed non-float types (boolean, char, Object, void). boolean floatOrSigned = (((this.format & source.format) & Format.SIGNED) != 0); if (!floatOrSigned) { if (this.isOther()) return true; // can convert char to int or wider, but nothing else if (source.format == Format.CHAR) return true; // no other conversions are classified as widening return false; } // All signed and float conversions in the enum order are widening. assert(this.isFloating() || this.isSigned()); assert(source.isFloating() || source.isSigned()); return true; } static { assert(checkConvertibleFrom()); assert(COUNT == Wrapper.values().length); } private static boolean checkConvertibleFrom() { // Check the matrix for correct classification of widening conversions. for (Wrapper w : values()) { assert(w.isConvertibleFrom(w)); assert(VOID.isConvertibleFrom(w)); if (w != VOID) { assert(OBJECT.isConvertibleFrom(w)); assert(!w.isConvertibleFrom(VOID)); } // check relations with unsigned integral types: if (w != CHAR) { assert(!CHAR.isConvertibleFrom(w)); if (!w.isConvertibleFrom(INT)) assert(!w.isConvertibleFrom(CHAR)); } if (w != BOOLEAN) { assert(!BOOLEAN.isConvertibleFrom(w)); if (w != VOID && w != OBJECT) assert(!w.isConvertibleFrom(BOOLEAN)); } // check relations with signed integral types: if (w.isSigned()) { for (Wrapper x : values()) { if (w == x) continue; if (x.isFloating()) assert(!w.isConvertibleFrom(x)); else if (x.isSigned()) { if (w.compareTo(x) < 0) assert(!w.isConvertibleFrom(x)); else assert(w.isConvertibleFrom(x)); } } } // check relations with floating types: if (w.isFloating()) { for (Wrapper x : values()) { if (w == x) continue; if (x.isSigned()) assert(w.isConvertibleFrom(x)); else if (x.isFloating()) { if (w.compareTo(x) < 0) assert(!w.isConvertibleFrom(x)); else assert(w.isConvertibleFrom(x)); } } } } return true; // i.e., assert(true) } /** Produce a zero value for the given wrapper type. * This will be a numeric zero for a number or character, * false for a boolean, and null for a reference or void. * The common thread is that this is what is contained * in a default-initialized variable of the given primitive * type. (For void, it is what a reflective method returns * instead of no value at all.) */ public Object zero() { switch (this) { case BOOLEAN: return Boolean.FALSE; case INT: return (Integer)0; case BYTE: return (Byte)(byte)0; case CHAR: return (Character)(char)0; case SHORT: return (Short)(short)0; case LONG: return (Long)(long)0; case FLOAT: return FLOAT_ZERO; case DOUBLE: return DOUBLE_ZERO; case VOID: case OBJECT: default: return null; } } private static final Object DOUBLE_ZERO = (Double)(double)0; private static final Object FLOAT_ZERO = (Float)(float)0; /** Produce a zero value for the given wrapper type T. * The optional argument must a type compatible with this wrapper. * Equivalent to {@code this.cast(this.zero(), type)}. */ public T zero(Class type) { return convert(zero(), type); } /** Return the wrapper that wraps values of the given type. * The type may be {@code Object}, meaning the {@code OBJECT} wrapper. * Otherwise, the type must be a primitive. * @throws IllegalArgumentException for unexpected types */ public static Wrapper forPrimitiveType(Class type) { Wrapper w = findPrimitiveType(type); if (w != null) return w; if (type.isPrimitive()) throw new InternalError(); // redo hash function throw newIllegalArgumentException("not primitive: "+type); } /** Return the wrapper that corresponds to the provided basic type char. * The basic type char must be for one of the eight primitive types, or void. * @throws IllegalArgumentException for unexpected types */ public static Wrapper forPrimitiveType(char basicTypeChar) { switch (basicTypeChar) { case 'I': return INT; case 'J': return LONG; case 'S': return SHORT; case 'B': return BYTE; case 'C': return CHAR; case 'F': return FLOAT; case 'D': return DOUBLE; case 'Z': return BOOLEAN; case 'V': return VOID; default: throw newIllegalArgumentException("not primitive: " + basicTypeChar); } } static Wrapper findPrimitiveType(Class type) { Wrapper w = FROM_PRIM[hashPrim(type)]; if (w != null && w.primitiveType == type) { return w; } return null; } /** Return the wrapper that wraps values into the given wrapper type. * If it is {@code Object}, return {@code OBJECT}. * Otherwise, it must be a wrapper type. * The type must not be a primitive type. * @throws IllegalArgumentException for unexpected types */ public static Wrapper forWrapperType(Class type) { Wrapper w = findWrapperType(type); if (w != null) return w; for (Wrapper x : values()) if (x.wrapperType == type) throw new InternalError(); // redo hash function throw newIllegalArgumentException("not wrapper: "+type); } static Wrapper findWrapperType(Class type) { Wrapper w = FROM_WRAP[hashWrap(type)]; if (w != null && w.wrapperType == type) { return w; } return null; } /** Return the wrapper that corresponds to the given bytecode * signature character. Return {@code OBJECT} for the character 'L'. * @throws IllegalArgumentException for any non-signature character or {@code '['}. */ public static Wrapper forBasicType(char type) { Wrapper w = FROM_CHAR[hashChar(type)]; if (w != null && w.basicTypeChar == type) { return w; } for (Wrapper x : values()) if (w.basicTypeChar == type) throw new InternalError(); // redo hash function throw newIllegalArgumentException("not basic type char: "+type); } /** Return the wrapper for the given type, if it is * a primitive type, else return {@code OBJECT}. */ public static Wrapper forBasicType(Class type) { if (type.isPrimitive()) return forPrimitiveType(type); return OBJECT; // any reference, including wrappers or arrays } // Note on perfect hashes: // for signature chars c, do (c + (c >> 1)) % 16 // for primitive type names n, do (n[0] + n[2]) % 16 // The type name hash works for both primitive and wrapper names. // You can add "java/lang/Object" to the primitive names. // But you add the wrapper name Object, use (n[2] + (3*n[1])) % 16. private static final Wrapper[] FROM_PRIM = new Wrapper[16]; private static final Wrapper[] FROM_WRAP = new Wrapper[16]; private static final Wrapper[] FROM_CHAR = new Wrapper[16]; private static int hashPrim(Class x) { String xn = x.getName(); if (xn.length() < 3) return 0; return (xn.charAt(0) + xn.charAt(2)) % 16; } private static int hashWrap(Class x) { String xn = x.getName(); final int offset = 10; assert(offset == "java.lang.".length()); if (xn.length() < offset+3) return 0; return (3*xn.charAt(offset+1) + xn.charAt(offset+2)) % 16; } private static int hashChar(char x) { return (x + (x >> 1)) % 16; } static { for (Wrapper w : values()) { int pi = hashPrim(w.primitiveType); int wi = hashWrap(w.wrapperType); int ci = hashChar(w.basicTypeChar); assert(FROM_PRIM[pi] == null); assert(FROM_WRAP[wi] == null); assert(FROM_CHAR[ci] == null); FROM_PRIM[pi] = w; FROM_WRAP[wi] = w; FROM_CHAR[ci] = w; } //assert(jdk.sun.invoke.util.WrapperTest.test(false)); } /** What is the primitive type wrapped by this wrapper? */ public Class primitiveType() { return primitiveType; } /** What is the wrapper type for this wrapper? */ public Class wrapperType() { return wrapperType; } /** What is the wrapper type for this wrapper? * Otherwise, the example type must be the wrapper type, * or the corresponding primitive type. * (For {@code OBJECT}, the example type can be any non-primitive, * and is normalized to {@code Object.class}.) * The resulting class type has the same type parameter. */ public Class wrapperType(Class exampleType) { if (exampleType == wrapperType) { return exampleType; } else if (exampleType == primitiveType || wrapperType == Object.class || exampleType.isInterface()) { return forceType(wrapperType, exampleType); } throw newClassCastException(exampleType, primitiveType); } private static ClassCastException newClassCastException(Class actual, Class expected) { return new ClassCastException(actual + " is not compatible with " + expected); } /** If {@code type} is a primitive type, return the corresponding * wrapper type, else return {@code type} unchanged. */ public static Class asWrapperType(Class type) { if (type.isPrimitive()) { return forPrimitiveType(type).wrapperType(type); } return type; } /** If {@code type} is a wrapper type, return the corresponding * primitive type, else return {@code type} unchanged. */ public static Class asPrimitiveType(Class type) { Wrapper w = findWrapperType(type); if (w != null) { return forceType(w.primitiveType(), type); } return type; } /** Query: Is the given type a wrapper, such as {@code Integer} or {@code Void}? */ public static boolean isWrapperType(Class type) { return findWrapperType(type) != null; } /** Query: Is the given type a primitive, such as {@code int} or {@code void}? */ public static boolean isPrimitiveType(Class type) { return type.isPrimitive(); } /** What is the bytecode signature character for this type? * All non-primitives, including array types, report as 'L', the signature character for references. */ public static char basicTypeChar(Class type) { if (!type.isPrimitive()) return 'L'; else return forPrimitiveType(type).basicTypeChar(); } /** What is the bytecode signature character for this wrapper's * primitive type? */ public char basicTypeChar() { return basicTypeChar; } /** What is the bytecode signature string for this wrapper's * primitive type? */ public String basicTypeString() { return basicTypeString; } /** What is the simple name of the wrapper type? */ public String wrapperSimpleName() { return wrapperSimpleName; } /** What is the simple name of the primitive type? */ public String primitiveSimpleName() { return primitiveSimpleName; } // /** Wrap a value in the given type, which may be either a primitive or wrapper type. // * Performs standard primitive conversions, including truncation and float conversions. // */ // public static T wrap(Object x, Class type) { // return Wrapper.valueOf(type).cast(x, type); // } /** Cast a wrapped value to the given type, which may be either a primitive or wrapper type. * The given target type must be this wrapper's primitive or wrapper type. * If this wrapper is OBJECT, the target type may also be an interface, perform no runtime check. * Performs standard primitive conversions, including truncation and float conversions. * The given type must be compatible with this wrapper. That is, it must either * be the wrapper type (or a subtype, in the case of {@code OBJECT}) or else * it must be the wrapper's primitive type. * Primitive conversions are only performed if the given type is itself a primitive. * @throws ClassCastException if the given type is not compatible with this wrapper */ public T cast(Object x, Class type) { return convert(x, type, true); } /** Convert a wrapped value to the given type. * The given target type must be this wrapper's primitive or wrapper type. * This is equivalent to {@link #cast}, except that it refuses to perform * narrowing primitive conversions. */ public T convert(Object x, Class type) { return convert(x, type, false); } private T convert(Object x, Class type, boolean isCast) { if (this == OBJECT) { // If the target wrapper is OBJECT, just do a reference cast. // If the target type is an interface, perform no runtime check. // (This loophole is safe, and is allowed by the JVM verifier.) // If the target type is a primitive, change it to a wrapper. assert(!type.isPrimitive()); if (!type.isInterface()) type.cast(x); @SuppressWarnings("unchecked") T result = (T) x; // unchecked warning is expected here return result; } Class wtype = wrapperType(type); if (wtype.isInstance(x)) { return wtype.cast(x); } if (!isCast) { Class sourceType = x.getClass(); // throw NPE if x is null Wrapper source = findWrapperType(sourceType); if (source == null || !this.isConvertibleFrom(source)) { throw newClassCastException(wtype, sourceType); } } else if (x == null) { @SuppressWarnings("unchecked") T z = (T) zero(); return z; } @SuppressWarnings("unchecked") T result = (T) wrap(x); // unchecked warning is expected here assert (result == null ? Void.class : result.getClass()) == wtype; return result; } /** Cast a reference type to another reference type. * If the target type is an interface, perform no runtime check. * (This loophole is safe, and is allowed by the JVM verifier.) * If the target type is a primitive, change it to a wrapper. */ static Class forceType(Class type, Class exampleType) { assert(type == exampleType || type.isPrimitive() && forPrimitiveType(type) == findWrapperType(exampleType) || exampleType.isPrimitive() && forPrimitiveType(exampleType) == findWrapperType(type) || type == Object.class && !exampleType.isPrimitive()); @SuppressWarnings("unchecked") Class result = (Class) type; // unchecked warning is expected here return result; } /** Wrap a value in this wrapper's type. * Performs standard primitive conversions, including truncation and float conversions. * Performs returns the unchanged reference for {@code OBJECT}. * Returns null for {@code VOID}. * Returns a zero value for a null input. * @throws ClassCastException if this wrapper is numeric and the operand * is not a number, character, boolean, or null */ public Object wrap(Object x) { // do non-numeric wrappers first switch (basicTypeChar) { case 'L': return x; case 'V': return null; } Number xn = numberValue(x); switch (basicTypeChar) { case 'I': return Integer.valueOf(xn.intValue()); case 'J': return Long.valueOf(xn.longValue()); case 'F': return Float.valueOf(xn.floatValue()); case 'D': return Double.valueOf(xn.doubleValue()); case 'S': return Short.valueOf((short) xn.intValue()); case 'B': return Byte.valueOf((byte) xn.intValue()); case 'C': return Character.valueOf((char) xn.intValue()); case 'Z': return Boolean.valueOf(boolValue(xn.byteValue())); } throw new InternalError("bad wrapper"); } /** Wrap a value (an int or smaller value) in this wrapper's type. * Performs standard primitive conversions, including truncation and float conversions. * Produces an {@code Integer} for {@code OBJECT}, although the exact type * of the operand is not known. * Returns null for {@code VOID}. */ public Object wrap(int x) { switch (basicTypeChar) { case 'L': return (Integer)x; case 'V': return null; case 'I': return Integer.valueOf(x); case 'J': return Long.valueOf(x); case 'F': return Float.valueOf(x); case 'D': return Double.valueOf(x); case 'S': return Short.valueOf((short) x); case 'B': return Byte.valueOf((byte) x); case 'C': return Character.valueOf((char) x); case 'Z': return Boolean.valueOf(boolValue((byte) x)); } throw new InternalError("bad wrapper"); } private static Number numberValue(Object x) { if (x instanceof Number) return (Number)x; if (x instanceof Character) return (int)(Character)x; if (x instanceof Boolean) return (Boolean)x ? 1 : 0; // Remaining allowed case of void: Must be a null reference. return (Number)x; } // Parameter type of boolValue must be byte, because // MethodHandles.explicitCastArguments defines boolean // conversion as first converting to byte. private static boolean boolValue(byte bits) { bits &= 1; // simple 31-bit zero extension return (bits != 0); } private static RuntimeException newIllegalArgumentException(String message, Object x) { return newIllegalArgumentException(message + x); } private static RuntimeException newIllegalArgumentException(String message) { return new IllegalArgumentException(message); } // primitive array support public Object makeArray(int len) { return java.lang.reflect.Array.newInstance(primitiveType, len); } public Class arrayType() { return emptyArray.getClass(); } public void copyArrayUnboxing(Object[] values, int vpos, Object a, int apos, int length) { if (a.getClass() != arrayType()) arrayType().cast(a); // throw NPE or CCE if bad type for (int i = 0; i < length; i++) { Object value = values[i+vpos]; value = convert(value, primitiveType); java.lang.reflect.Array.set(a, i+apos, value); } } public void copyArrayBoxing(Object a, int apos, Object[] values, int vpos, int length) { if (a.getClass() != arrayType()) arrayType().cast(a); // throw NPE or CCE if bad type for (int i = 0; i < length; i++) { Object value = java.lang.reflect.Array.get(a, i+apos); //Already done: value = convert(value, primitiveType); assert(value.getClass() == wrapperType); values[i+vpos] = value; } } }




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