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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * particular file as subject to the "Classpath" exception as provided
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 * 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).
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package jdk.nashorn.internal.runtime.linker;

import static jdk.nashorn.internal.lookup.Lookup.MH;
import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
import static jdk.nashorn.internal.runtime.JSType.isString;
import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.util.HashMap;
import java.util.Map;
import jdk.dynalink.linker.support.TypeUtilities;
import jdk.nashorn.internal.runtime.ConsString;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.ScriptObject;

Utility class shared by NashornLinker and NashornPrimitiveLinker for converting JS values to Java types.
/** * Utility class shared by {@code NashornLinker} and {@code NashornPrimitiveLinker} for converting JS values to Java * types. */
final class JavaArgumentConverters { private static final MethodHandle TO_BOOLEAN = findOwnMH("toBoolean", Boolean.class, Object.class); private static final MethodHandle TO_STRING = findOwnMH("toString", String.class, Object.class); private static final MethodHandle TO_DOUBLE = findOwnMH("toDouble", Double.class, Object.class); private static final MethodHandle TO_NUMBER = findOwnMH("toNumber", Number.class, Object.class); private static final MethodHandle TO_LONG = findOwnMH("toLong", Long.class, Object.class); private static final MethodHandle TO_LONG_PRIMITIVE = findOwnMH("toLongPrimitive", long.class, Object.class); private static final MethodHandle TO_CHAR = findOwnMH("toChar", Character.class, Object.class); private static final MethodHandle TO_CHAR_PRIMITIVE = findOwnMH("toCharPrimitive", char.class, Object.class); private JavaArgumentConverters() { } static MethodHandle getConverter(final Class<?> targetType) { return CONVERTERS.get(targetType); } @SuppressWarnings("unused") private static Boolean toBoolean(final Object obj) { if (obj instanceof Boolean) { return (Boolean) obj; } if (obj == null) { // NOTE: FindBugs complains here about the NP_BOOLEAN_RETURN_NULL pattern: we're returning null from a // method that has a return type of Boolean, as it is worried about a NullPointerException if there's a // conversion to a primitive boolean. We know what we're doing, though. We're using a separate method when // we're converting Object to a primitive boolean - see how the CONVERTERS map is populated. We specifically // want to have null and Undefined to be converted to a (Boolean)null when being passed to a Java method // that expects a Boolean argument. // TODO: if/when we're allowed to use FindBugs at build time, we can use annotations to disable this warning return null; } if (obj == UNDEFINED) { // NOTE: same reasoning for FindBugs NP_BOOLEAN_RETURN_NULL warning as in the preceding comment. return null; } if (obj instanceof Number) { final double num = ((Number) obj).doubleValue(); return num != 0 && !Double.isNaN(num); } if (isString(obj)) { return ((CharSequence) obj).length() > 0; } if (obj instanceof ScriptObject) { return true; } throw assertUnexpectedType(obj); } private static Character toChar(final Object o) { if (o == null) { return null; } if (o instanceof Number) { final int ival = ((Number)o).intValue(); if (ival >= Character.MIN_VALUE && ival <= Character.MAX_VALUE) { return (char) ival; } throw typeError("cant.convert.number.to.char"); } final String s = toString(o); if (s == null) { return null; } if (s.length() != 1) { throw typeError("cant.convert.string.to.char"); } return s.charAt(0); } static char toCharPrimitive(final Object obj0) { final Character c = toChar(obj0); return c == null ? (char)0 : c; } // Almost identical to ScriptRuntime.toString, but returns null for null instead of the string "null". static String toString(final Object obj) { return obj == null ? null : JSType.toString(obj); } @SuppressWarnings("unused") private static Double toDouble(final Object obj0) { // TODO - Order tests for performance. for (Object obj = obj0; ;) { if (obj == null) { return null; } else if (obj instanceof Double) { return (Double) obj; } else if (obj instanceof Number) { return ((Number)obj).doubleValue(); } else if (obj instanceof String) { return JSType.toNumber((String) obj); } else if (obj instanceof ConsString) { return JSType.toNumber(obj.toString()); } else if (obj instanceof Boolean) { return (Boolean) obj ? 1 : +0.0; } else if (obj instanceof ScriptObject) { obj = JSType.toPrimitive(obj, Number.class); continue; } else if (obj == UNDEFINED) { return Double.NaN; } throw assertUnexpectedType(obj); } } @SuppressWarnings("unused") private static Number toNumber(final Object obj0) { // TODO - Order tests for performance. for (Object obj = obj0; ;) { if (obj == null) { return null; } else if (obj instanceof Number) { return (Number) obj; } else if (obj instanceof String) { return JSType.toNumber((String) obj); } else if (obj instanceof ConsString) { return JSType.toNumber(obj.toString()); } else if (obj instanceof Boolean) { return (Boolean) obj ? 1 : +0.0; } else if (obj instanceof ScriptObject) { obj = JSType.toPrimitive(obj, Number.class); continue; } else if (obj == UNDEFINED) { return Double.NaN; } throw assertUnexpectedType(obj); } } private static Long toLong(final Object obj0) { // TODO - Order tests for performance. for (Object obj = obj0; ;) { if (obj == null) { return null; } else if (obj instanceof Long) { return (Long) obj; } else if (obj instanceof Integer) { return ((Integer)obj).longValue(); } else if (obj instanceof Double) { final Double d = (Double)obj; if(Double.isInfinite(d)) { return 0L; } return d.longValue(); } else if (obj instanceof Float) { final Float f = (Float)obj; if(Float.isInfinite(f)) { return 0L; } return f.longValue(); } else if (obj instanceof Number) { return ((Number)obj).longValue(); } else if (isString(obj)) { return JSType.toLong(obj); } else if (obj instanceof Boolean) { return (Boolean)obj ? 1L : 0L; } else if (obj instanceof ScriptObject) { obj = JSType.toPrimitive(obj, Number.class); continue; } else if (obj == UNDEFINED) { return null; // null or 0L? } throw assertUnexpectedType(obj); } } private static AssertionError assertUnexpectedType(final Object obj) { return new AssertionError("Unexpected type" + obj.getClass().getName() + ". Guards should have prevented this"); } @SuppressWarnings("unused") private static long toLongPrimitive(final Object obj0) { final Long l = toLong(obj0); return l == null ? 0L : l; } private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { return MH.findStatic(MethodHandles.lookup(), JavaArgumentConverters.class, name, MH.type(rtype, types)); } private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>(); static { CONVERTERS.put(Number.class, TO_NUMBER); CONVERTERS.put(String.class, TO_STRING); CONVERTERS.put(boolean.class, JSType.TO_BOOLEAN.methodHandle()); CONVERTERS.put(Boolean.class, TO_BOOLEAN); CONVERTERS.put(char.class, TO_CHAR_PRIMITIVE); CONVERTERS.put(Character.class, TO_CHAR); CONVERTERS.put(double.class, JSType.TO_NUMBER.methodHandle()); CONVERTERS.put(Double.class, TO_DOUBLE); CONVERTERS.put(long.class, TO_LONG_PRIMITIVE); CONVERTERS.put(Long.class, TO_LONG); putLongConverter(Byte.class); putLongConverter(Short.class); putLongConverter(Integer.class); putDoubleConverter(Float.class); } private static void putDoubleConverter(final Class<?> targetType) { final Class<?> primitive = TypeUtilities.getPrimitiveType(targetType); CONVERTERS.put(primitive, MH.explicitCastArguments(JSType.TO_NUMBER.methodHandle(), JSType.TO_NUMBER.methodHandle().type().changeReturnType(primitive))); CONVERTERS.put(targetType, MH.filterReturnValue(TO_DOUBLE, findOwnMH(primitive.getName() + "Value", targetType, Double.class))); } private static void putLongConverter(final Class<?> targetType) { final Class<?> primitive = TypeUtilities.getPrimitiveType(targetType); CONVERTERS.put(primitive, MH.explicitCastArguments(TO_LONG_PRIMITIVE, TO_LONG_PRIMITIVE.type().changeReturnType(primitive))); CONVERTERS.put(targetType, MH.filterReturnValue(TO_LONG, findOwnMH(primitive.getName() + "Value", targetType, Long.class))); } @SuppressWarnings("unused") private static Byte byteValue(final Long l) { return l == null ? null : l.byteValue(); } @SuppressWarnings("unused") private static Short shortValue(final Long l) { return l == null ? null : l.shortValue(); } @SuppressWarnings("unused") private static Integer intValue(final Long l) { return l == null ? null : l.intValue(); } @SuppressWarnings("unused") private static Float floatValue(final Double d) { return d == null ? null : d.floatValue(); } }