| /* |
| * Copyright (c) 2010, 2013, 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 |
| * questions. |
| */ |
| |
| package jdk.nashorn.internal.runtime.linker; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodHandles.Lookup; |
| import java.lang.invoke.MethodType; |
| import java.security.AccessControlContext; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import jdk.internal.dynalink.CallSiteDescriptor; |
| import jdk.internal.dynalink.CompositeOperation; |
| import jdk.internal.dynalink.NamedOperation; |
| import jdk.internal.dynalink.Operation; |
| import jdk.internal.dynalink.StandardOperation; |
| import jdk.internal.dynalink.support.NameCodec; |
| import jdk.nashorn.internal.ir.debug.NashornTextifier; |
| import jdk.nashorn.internal.runtime.AccessControlContextFactory; |
| import jdk.nashorn.internal.runtime.ScriptRuntime; |
| |
| /** |
| * Nashorn-specific implementation of Dynalink's {@link CallSiteDescriptor}. |
| * The reason we have our own subclass is that we're storing flags in an |
| * additional primitive field. The class also exposes some useful utilities in |
| * form of static methods. |
| */ |
| public final class NashornCallSiteDescriptor extends CallSiteDescriptor { |
| // Lowest three bits describe the operation |
| /** Property getter operation {@code obj.prop} */ |
| public static final int GET_PROPERTY = 0; |
| /** Element getter operation {@code obj[index]} */ |
| public static final int GET_ELEMENT = 1; |
| /** Property getter operation, subsequently invoked {@code obj.prop()} */ |
| public static final int GET_METHOD_PROPERTY = 2; |
| /** Element getter operation, subsequently invoked {@code obj[index]()} */ |
| public static final int GET_METHOD_ELEMENT = 3; |
| /** Property setter operation {@code obj.prop = value} */ |
| public static final int SET_PROPERTY = 4; |
| /** Element setter operation {@code obj[index] = value} */ |
| public static final int SET_ELEMENT = 5; |
| /** Call operation {@code fn(args...)} */ |
| public static final int CALL = 6; |
| /** New operation {@code new Constructor(args...)} */ |
| public static final int NEW = 7; |
| |
| private static final int OPERATION_MASK = 7; |
| |
| // Correspond to the operation indices above. |
| private static final Operation[] OPERATIONS = new Operation[] { |
| new CompositeOperation(StandardOperation.GET_PROPERTY, StandardOperation.GET_ELEMENT, StandardOperation.GET_METHOD), |
| new CompositeOperation(StandardOperation.GET_ELEMENT, StandardOperation.GET_PROPERTY, StandardOperation.GET_METHOD), |
| new CompositeOperation(StandardOperation.GET_METHOD, StandardOperation.GET_PROPERTY, StandardOperation.GET_ELEMENT), |
| new CompositeOperation(StandardOperation.GET_METHOD, StandardOperation.GET_ELEMENT, StandardOperation.GET_PROPERTY), |
| new CompositeOperation(StandardOperation.SET_PROPERTY, StandardOperation.SET_ELEMENT), |
| new CompositeOperation(StandardOperation.SET_ELEMENT, StandardOperation.SET_PROPERTY), |
| StandardOperation.CALL, |
| StandardOperation.NEW |
| }; |
| |
| /** Flags that the call site references a scope variable (it's an identifier reference or a var declaration, not a |
| * property access expression. */ |
| public static final int CALLSITE_SCOPE = 1 << 3; |
| /** Flags that the call site is in code that uses ECMAScript strict mode. */ |
| public static final int CALLSITE_STRICT = 1 << 4; |
| /** Flags that a property getter or setter call site references a scope variable that is located at a known distance |
| * in the scope chain. Such getters and setters can often be linked more optimally using these assumptions. */ |
| public static final int CALLSITE_FAST_SCOPE = 1 << 5; |
| /** Flags that a callsite type is optimistic, i.e. we might get back a wider return value than encoded in the |
| * descriptor, and in that case we have to throw an UnwarrantedOptimismException */ |
| public static final int CALLSITE_OPTIMISTIC = 1 << 6; |
| /** Is this really an apply that we try to call as a call? */ |
| public static final int CALLSITE_APPLY_TO_CALL = 1 << 7; |
| /** Does this a callsite for a variable declaration? */ |
| public static final int CALLSITE_DECLARE = 1 << 8; |
| |
| /** Flags that the call site is profiled; Contexts that have {@code "profile.callsites"} boolean property set emit |
| * code where call sites have this flag set. */ |
| public static final int CALLSITE_PROFILE = 1 << 9; |
| /** Flags that the call site is traced; Contexts that have {@code "trace.callsites"} property set emit code where |
| * call sites have this flag set. */ |
| public static final int CALLSITE_TRACE = 1 << 10; |
| /** Flags that the call site linkage miss (and thus, relinking) is traced; Contexts that have the keyword |
| * {@code "miss"} in their {@code "trace.callsites"} property emit code where call sites have this flag set. */ |
| public static final int CALLSITE_TRACE_MISSES = 1 << 11; |
| /** Flags that entry/exit to/from the method linked at call site are traced; Contexts that have the keyword |
| * {@code "enterexit"} in their {@code "trace.callsites"} property emit code where call sites have this flag set. */ |
| public static final int CALLSITE_TRACE_ENTEREXIT = 1 << 12; |
| /** Flags that values passed as arguments to and returned from the method linked at call site are traced; Contexts |
| * that have the keyword {@code "values"} in their {@code "trace.callsites"} property emit code where call sites |
| * have this flag set. */ |
| public static final int CALLSITE_TRACE_VALUES = 1 << 13; |
| |
| //we could have more tracing flags here, for example CALLSITE_TRACE_SCOPE, but bits are a bit precious |
| //right now given the program points |
| |
| /** |
| * Number of bits the program point is shifted to the left in the flags (lowest bit containing a program point). |
| * Always one larger than the largest flag shift. Note that introducing a new flag halves the number of program |
| * points we can have. |
| * TODO: rethink if we need the various profile/trace flags or the linker can use the Context instead to query its |
| * trace/profile settings. |
| */ |
| public static final int CALLSITE_PROGRAM_POINT_SHIFT = 14; |
| |
| /** |
| * Maximum program point value. We have 18 bits left over after flags, and |
| * it should be plenty. Program points are local to a single function. Every |
| * function maps to a single JVM bytecode method that can have at most 65535 |
| * bytes. (Large functions are synthetically split into smaller functions.) |
| * A single invokedynamic is 5 bytes; even if a method consists of only |
| * invokedynamic instructions that leaves us with at most 65535/5 = 13107 |
| * program points for the largest single method; those can be expressed on |
| * 14 bits. It is true that numbering of program points is independent of |
| * bytecode representation, but if a function would need more than ~14 bits |
| * for the program points, then it is reasonable to presume splitter |
| * would've split it into several smaller functions already. |
| */ |
| public static final int MAX_PROGRAM_POINT_VALUE = (1 << 32 - CALLSITE_PROGRAM_POINT_SHIFT) - 1; |
| |
| /** |
| * Flag mask to get the program point flags |
| */ |
| public static final int FLAGS_MASK = (1 << CALLSITE_PROGRAM_POINT_SHIFT) - 1; |
| |
| private static final ClassValue<ConcurrentMap<NashornCallSiteDescriptor, NashornCallSiteDescriptor>> canonicals = |
| new ClassValue<ConcurrentMap<NashornCallSiteDescriptor,NashornCallSiteDescriptor>>() { |
| @Override |
| protected ConcurrentMap<NashornCallSiteDescriptor, NashornCallSiteDescriptor> computeValue(final Class<?> type) { |
| return new ConcurrentHashMap<>(); |
| } |
| }; |
| |
| private static final AccessControlContext GET_LOOKUP_PERMISSION_CONTEXT = |
| AccessControlContextFactory.createAccessControlContext(CallSiteDescriptor.GET_LOOKUP_PERMISSION_NAME); |
| |
| private final int flags; |
| |
| /** |
| * Function used by {@link NashornTextifier} to represent call site flags in |
| * human readable form |
| * @param flags call site flags |
| * @return human readable form of this callsite descriptor |
| */ |
| public static String toString(final int flags) { |
| final StringBuilder sb = new StringBuilder(); |
| if ((flags & CALLSITE_SCOPE) != 0) { |
| if ((flags & CALLSITE_FAST_SCOPE) != 0) { |
| sb.append("fastscope "); |
| } else { |
| assert (flags & CALLSITE_FAST_SCOPE) == 0 : "can't be fastscope without scope"; |
| sb.append("scope "); |
| } |
| if ((flags & CALLSITE_DECLARE) != 0) { |
| sb.append("declare "); |
| } |
| } |
| if ((flags & CALLSITE_APPLY_TO_CALL) != 0) { |
| sb.append("apply2call "); |
| } |
| if ((flags & CALLSITE_STRICT) != 0) { |
| sb.append("strict "); |
| } |
| return sb.length() == 0 ? "" : " " + sb.toString().trim(); |
| } |
| |
| /** |
| * Given call site flags, returns the operation name encoded in them. |
| * @param flags flags |
| * @return the operation name |
| */ |
| public static String getOperationName(final int flags) { |
| switch(flags & OPERATION_MASK) { |
| case 0: return "GET_PROPERTY"; |
| case 1: return "GET_ELEMENT"; |
| case 2: return "GET_METHOD_PROPERTY"; |
| case 3: return "GET_METHOD_ELEMENT"; |
| case 4: return "SET_PROPERTY"; |
| case 5: return "SET_ELEMENT"; |
| case 6: return "CALL"; |
| case 7: return "NEW"; |
| default: throw new AssertionError(); |
| } |
| } |
| |
| /** |
| * Retrieves a Nashorn call site descriptor with the specified values. Since call site descriptors are immutable |
| * this method is at liberty to retrieve canonicalized instances (although it is not guaranteed it will do so). |
| * @param lookup the lookup describing the script |
| * @param name the name at the call site. Can not be null, but it can be empty. |
| * @param methodType the method type at the call site |
| * @param flags Nashorn-specific call site flags |
| * @return a call site descriptor with the specified values. |
| */ |
| public static NashornCallSiteDescriptor get(final MethodHandles.Lookup lookup, final String name, |
| final MethodType methodType, final int flags) { |
| final Operation baseOp = OPERATIONS[flags & OPERATION_MASK]; |
| final String decodedName = NameCodec.decode(name); |
| // TODO: introduce caching of NamedOperation |
| final Operation op = decodedName.isEmpty() ? baseOp : new NamedOperation(baseOp, decodedName); |
| return get(lookup, op, methodType, flags); |
| } |
| |
| private static NashornCallSiteDescriptor get(final MethodHandles.Lookup lookup, final Operation operation, final MethodType methodType, final int flags) { |
| final NashornCallSiteDescriptor csd = new NashornCallSiteDescriptor(lookup, operation, methodType, flags); |
| // Many of these call site descriptors are identical (e.g. every getter for a property color will be |
| // "GET_PROPERTY:color(Object)Object", so it makes sense canonicalizing them. |
| final ConcurrentMap<NashornCallSiteDescriptor, NashornCallSiteDescriptor> classCanonicals = canonicals.get(lookup.lookupClass()); |
| final NashornCallSiteDescriptor canonical = classCanonicals.putIfAbsent(csd, csd); |
| return canonical != null ? canonical : csd; |
| } |
| |
| private NashornCallSiteDescriptor(final MethodHandles.Lookup lookup, final Operation operation, final MethodType methodType, final int flags) { |
| super(lookup, operation, methodType); |
| this.flags = flags; |
| } |
| |
| static Lookup getLookupInternal(final CallSiteDescriptor csd) { |
| if (csd instanceof NashornCallSiteDescriptor) { |
| return ((NashornCallSiteDescriptor)csd).getLookupPrivileged(); |
| } |
| return AccessController.doPrivileged((PrivilegedAction<Lookup>)()->csd.getLookup(), GET_LOOKUP_PERMISSION_CONTEXT); |
| } |
| |
| @Override |
| public boolean equals(final Object obj) { |
| return super.equals(obj) && flags == ((NashornCallSiteDescriptor)obj).flags; |
| } |
| |
| @Override |
| public int hashCode() { |
| return super.hashCode() ^ flags; |
| } |
| |
| /** |
| * Returns the named operand in this descriptor's operation. Equivalent to |
| * {@code ((NamedOperation)getOperation()).getName().toString()} for call |
| * sites with a named operand. For call sites without named operands returns null. |
| * @return the named operand in this descriptor's operation. |
| */ |
| public String getOperand() { |
| return getOperand(this); |
| } |
| |
| /** |
| * Returns the named operand in the passed descriptor's operation. |
| * Equivalent to |
| * {@code ((NamedOperation)desc.getOperation()).getName().toString()} for |
| * descriptors with a named operand. For descriptors without named operands |
| * returns null. |
| * @param desc the call site descriptors |
| * @return the named operand in this descriptor's operation. |
| */ |
| public static String getOperand(final CallSiteDescriptor desc) { |
| final Operation operation = desc.getOperation(); |
| return operation instanceof NamedOperation ? ((NamedOperation)operation).getName().toString() : null; |
| } |
| |
| /** |
| * Returns the first operation in this call site descriptor's potentially |
| * composite operation. E.g. if this call site descriptor has a composite |
| * operation {@code GET_PROPERTY|GET_METHOD|GET_ELEM}, it will return |
| * {@code GET_PROPERTY}. Nashorn - being a ECMAScript engine - does not |
| * distinguish between property, element, and method namespace; ECMAScript |
| * objects just have one single property namespace for all these, therefore |
| * it is largely irrelevant what the composite operation is structured like; |
| * if the first operation can't be satisfied, neither can the others. The |
| * first operation is however sometimes used to slightly alter the |
| * semantics; for example, a distinction between {@code GET_PROPERTY} and |
| * {@code GET_METHOD} being the first operation can translate into whether |
| * {@code "__noSuchProperty__"} or {@code "__noSuchMethod__"} will be |
| * executed in case the property is not found. Note that if a call site |
| * descriptor comes from outside of Nashorn, its class will be different, |
| * and there is no guarantee about the way it composes its operations. For |
| * that reason, for potentially foreign call site descriptors you should use |
| * {@link #getFirstStandardOperation(CallSiteDescriptor)} instead. |
| * @return the first operation in this call site descriptor. Note this will |
| * always be a {@code StandardOperation} as Nashorn internally only uses |
| * standard operations. |
| */ |
| public StandardOperation getFirstOperation() { |
| final Operation base = NamedOperation.getBaseOperation(getOperation()); |
| if (base instanceof CompositeOperation) { |
| return (StandardOperation)((CompositeOperation)base).getOperation(0); |
| } |
| return (StandardOperation)base; |
| } |
| |
| /** |
| * Returns the first standard operation in the (potentially composite) |
| * operation of the passed call site descriptor. |
| * @param desc the call site descriptor. |
| * @return Returns the first standard operation in the (potentially |
| * composite) operation of the passed call site descriptor. Can return null |
| * if the call site contains no standard operations. |
| */ |
| public static StandardOperation getFirstStandardOperation(final CallSiteDescriptor desc) { |
| final Operation base = NamedOperation.getBaseOperation(desc.getOperation()); |
| if (base instanceof StandardOperation) { |
| return (StandardOperation)base; |
| } else if (base instanceof CompositeOperation) { |
| final CompositeOperation cop = (CompositeOperation)base; |
| for(int i = 0; i < cop.getOperationCount(); ++i) { |
| final Operation op = cop.getOperation(i); |
| if (op instanceof StandardOperation) { |
| return (StandardOperation)op; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Returns true if the passed call site descriptor's operation contains (or |
| * is) the specified standard operation. |
| * @param desc the call site descriptor. |
| * @param operation the operation whose presence is tested. |
| * @return Returns true if the call site descriptor's operation contains (or |
| * is) the specified standard operation. |
| */ |
| public static boolean contains(final CallSiteDescriptor desc, final StandardOperation operation) { |
| return CompositeOperation.contains(NamedOperation.getBaseOperation(desc.getOperation()), operation); |
| } |
| |
| /** |
| * Returns the error message to be used when CALL or NEW is used on a non-function. |
| * |
| * @param obj object on which CALL or NEW is used |
| * @return error message |
| */ |
| public String getFunctionErrorMessage(final Object obj) { |
| final String funcDesc = getOperand(); |
| return funcDesc != null? funcDesc : ScriptRuntime.safeToString(obj); |
| } |
| |
| /** |
| * Returns the error message to be used when CALL or NEW is used on a non-function. |
| * |
| * @param desc call site descriptor |
| * @param obj object on which CALL or NEW is used |
| * @return error message |
| */ |
| public static String getFunctionErrorMessage(final CallSiteDescriptor desc, final Object obj) { |
| return desc instanceof NashornCallSiteDescriptor ? |
| ((NashornCallSiteDescriptor)desc).getFunctionErrorMessage(obj) : |
| ScriptRuntime.safeToString(obj); |
| } |
| |
| /** |
| * Returns the Nashorn-specific flags for this call site descriptor. |
| * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a |
| * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code |
| * generated outside of Nashorn. |
| * @return the Nashorn-specific flags for the call site, or 0 if the passed descriptor is not a Nashorn call site |
| * descriptor. |
| */ |
| public static int getFlags(final CallSiteDescriptor desc) { |
| return desc instanceof NashornCallSiteDescriptor ? ((NashornCallSiteDescriptor)desc).flags : 0; |
| } |
| |
| /** |
| * Returns true if this descriptor has the specified flag set, see {@code CALLSITE_*} constants in this class. |
| * @param flag the tested flag |
| * @return true if the flag is set, false otherwise |
| */ |
| private boolean isFlag(final int flag) { |
| return (flags & flag) != 0; |
| } |
| |
| /** |
| * Returns true if this descriptor has the specified flag set, see {@code CALLSITE_*} constants in this class. |
| * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a |
| * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code |
| * generated outside of Nashorn. |
| * @param flag the tested flag |
| * @return true if the flag is set, false otherwise (it will be false if the descriptor is not a Nashorn call site |
| * descriptor). |
| */ |
| private static boolean isFlag(final CallSiteDescriptor desc, final int flag) { |
| return (getFlags(desc) & flag) != 0; |
| } |
| |
| /** |
| * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_SCOPE} flag set. |
| * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a |
| * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code |
| * generated outside of Nashorn. |
| * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise. |
| */ |
| public static boolean isScope(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_SCOPE); |
| } |
| |
| /** |
| * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_FAST_SCOPE} flag set. |
| * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a |
| * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code |
| * generated outside of Nashorn. |
| * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise. |
| */ |
| public static boolean isFastScope(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_FAST_SCOPE); |
| } |
| |
| /** |
| * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_STRICT} flag set. |
| * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a |
| * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code |
| * generated outside of Nashorn. |
| * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise. |
| */ |
| public static boolean isStrict(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_STRICT); |
| } |
| |
| /** |
| * Returns true if this is an apply call that we try to call as |
| * a "call" |
| * @param desc descriptor |
| * @return true if apply to call |
| */ |
| public static boolean isApplyToCall(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_APPLY_TO_CALL); |
| } |
| |
| /** |
| * Is this an optimistic call site |
| * @param desc descriptor |
| * @return true if optimistic |
| */ |
| public static boolean isOptimistic(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_OPTIMISTIC); |
| } |
| |
| /** |
| * Does this callsite contain a declaration for its target? |
| * @param desc descriptor |
| * @return true if contains declaration |
| */ |
| public static boolean isDeclaration(final CallSiteDescriptor desc) { |
| return isFlag(desc, CALLSITE_DECLARE); |
| } |
| |
| /** |
| * Returns true if {@code flags} has the {@link #CALLSITE_STRICT} bit set. |
| * @param flags the flags |
| * @return true if the flag is set, false otherwise. |
| */ |
| public static boolean isStrictFlag(final int flags) { |
| return (flags & CALLSITE_STRICT) != 0; |
| } |
| |
| /** |
| * Returns true if {@code flags} has the {@link #CALLSITE_SCOPE} bit set. |
| * @param flags the flags |
| * @return true if the flag is set, false otherwise. |
| */ |
| public static boolean isScopeFlag(final int flags) { |
| return (flags & CALLSITE_SCOPE) != 0; |
| } |
| |
| /** |
| * Get a program point from a descriptor (must be optimistic) |
| * @param desc descriptor |
| * @return program point |
| */ |
| public static int getProgramPoint(final CallSiteDescriptor desc) { |
| assert isOptimistic(desc) : "program point requested from non-optimistic descriptor " + desc; |
| return getFlags(desc) >> CALLSITE_PROGRAM_POINT_SHIFT; |
| } |
| |
| boolean isProfile() { |
| return isFlag(CALLSITE_PROFILE); |
| } |
| |
| boolean isTrace() { |
| return isFlag(CALLSITE_TRACE); |
| } |
| |
| boolean isTraceMisses() { |
| return isFlag(CALLSITE_TRACE_MISSES); |
| } |
| |
| boolean isTraceEnterExit() { |
| return isFlag(CALLSITE_TRACE_ENTEREXIT); |
| } |
| |
| boolean isTraceObjects() { |
| return isFlag(CALLSITE_TRACE_VALUES); |
| } |
| |
| boolean isOptimistic() { |
| return isFlag(CALLSITE_OPTIMISTIC); |
| } |
| |
| @Override |
| public CallSiteDescriptor changeMethodTypeInternal(final MethodType newMethodType) { |
| return get(getLookupPrivileged(), getOperation(), newMethodType, flags); |
| } |
| } |
