/*
* Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package sun.invoke.util;
public enum Wrapper {
// wrapperType primitiveType char emptyArray format
BOOLEAN( Boolean.class, boolean.class, '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.class, 'B', new byte[0], Format.signed( 8)),
SHORT ( Short.class, short.class, 'S', new short[0], Format.signed( 16)),
CHAR (Character.class, char.class, 'C', new char[0], Format.unsigned(16)),
INT ( Integer.class, int.class, 'I', new int[0], Format.signed( 32)),
LONG ( Long.class, long.class, 'J', new long[0], Format.signed( 64)),
FLOAT ( Float.class, float.class, 'F', new float[0], Format.floating(32)),
DOUBLE ( Double.class, double.class, 'D', new double[0], Format.floating(64)),
OBJECT ( Object.class, Object.class, '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.class, '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 Object emptyArray;
private final int format;
private final String wrapperSimpleName;
private final String primitiveSimpleName;
private Wrapper(Class<?> wtype, Class<?> ptype, char tchar, Object emptyArray, int format) {
this.wrapperType = wtype;
this.primitiveType = ptype;
this.basicTypeChar = tchar;
this.emptyArray = emptyArray;
this.format = format;
this.wrapperSimpleName = wtype.getSimpleName();
this.primitiveSimpleName = ptype.getSimpleName();
}
/** 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:
* <ul>
* <li>unboxing followed by widening primitive conversion
* <li>any type converted to {@code void} (i.e., dropping a method call's value)
* <li>boxing conversion followed by widening reference conversion to {@code Object}
* </ul>
* 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> T zero(Class<T> 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);
}
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 <T> Class<T> wrapperType(Class<T> 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 <T> Class<T> asWrapperType(Class<T> 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 <T> Class<T> asPrimitiveType(Class<T> 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 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> T wrap(Object x, Class<T> 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> T cast(Object x, Class<T> 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> T convert(Object x, Class<T> type) {
return convert(x, type, false);
}
private <T> T convert(Object x, Class<T> 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<T> 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 <T> Class<T> forceType(Class<?> type, Class<T> exampleType) {
boolean z = (type == exampleType ||
type.isPrimitive() && forPrimitiveType(type) == findWrapperType(exampleType) ||
exampleType.isPrimitive() && forPrimitiveType(exampleType) == findWrapperType(type) ||
type == Object.class && !exampleType.isPrimitive());
if (!z)
System.out.println(type+" <= "+exampleType);
assert(type == exampleType ||
type.isPrimitive() && forPrimitiveType(type) == findWrapperType(exampleType) ||
exampleType.isPrimitive() && forPrimitiveType(exampleType) == findWrapperType(type) ||
type == Object.class && !exampleType.isPrimitive());
@SuppressWarnings("unchecked")
Class<T> result = (Class<T>) 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) {
if (basicTypeChar == 'L') return (Integer)x;
switch (basicTypeChar) {
case 'L': throw newIllegalArgumentException("cannot wrap to object type");
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;
}
}
}