| /* |
| * 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.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import jdk.internal.dynalink.CallSiteDescriptor; |
| import jdk.internal.dynalink.support.AbstractCallSiteDescriptor; |
| import jdk.internal.dynalink.support.CallSiteDescriptorFactory; |
| import jdk.nashorn.internal.ir.debug.NashornTextifier; |
| import jdk.nashorn.internal.runtime.ScriptRuntime; |
| |
| /** |
| * Nashorn-specific implementation of Dynalink's {@link CallSiteDescriptor}. The reason we have our own subclass is that |
| * we can have a more compact representation, as we know that we're always only using {@code "dyn:*"} operations; also |
| * we're storing flags in an additional primitive field. |
| */ |
| public final class NashornCallSiteDescriptor extends AbstractCallSiteDescriptor { |
| /** 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 << 0; |
| /** Flags that the call site is in code that uses ECMAScript strict mode. */ |
| public static final int CALLSITE_STRICT = 1 << 1; |
| /** 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 << 2; |
| /** 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 << 3; |
| /** Is this really an apply that we try to call as a call? */ |
| public static final int CALLSITE_APPLY_TO_CALL = 1 << 4; |
| /** Does this a callsite for a variable declaration? */ |
| public static final int CALLSITE_DECLARE = 1 << 5; |
| |
| /** 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 << 6; |
| /** 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 << 7; |
| /** 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 << 8; |
| /** 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 << 9; |
| /** 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 << 10; |
| |
| //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 = 11; |
| |
| /** |
| * Maximum program point value. 21 bits should be enough for anyone |
| */ |
| 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 final MethodHandles.Lookup lookup; |
| private final String operator; |
| private final String operand; |
| private final MethodType methodType; |
| 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(); |
| } |
| |
| /** |
| * 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, e.g. {@code "dyn:getProp|getElem|getMethod:color"}. |
| * @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 String[] tokenizedName = CallSiteDescriptorFactory.tokenizeName(name); |
| assert tokenizedName.length >= 2; |
| assert "dyn".equals(tokenizedName[0]); |
| assert tokenizedName[1] != null; |
| // TODO: see if we can move mangling/unmangling into Dynalink |
| return get(lookup, tokenizedName[1], tokenizedName.length == 3 ? tokenizedName[2].intern() : null, |
| methodType, flags); |
| } |
| |
| private static NashornCallSiteDescriptor get(final MethodHandles.Lookup lookup, final String operator, final String operand, final MethodType methodType, final int flags) { |
| final NashornCallSiteDescriptor csd = new NashornCallSiteDescriptor(lookup, operator, operand, methodType, flags); |
| // Many of these call site descriptors are identical (e.g. every getter for a property color will be |
| // "dyn:getProp: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 String operator, final String operand, |
| final MethodType methodType, final int flags) { |
| this.lookup = lookup; |
| this.operator = operator; |
| this.operand = operand; |
| this.methodType = methodType; |
| this.flags = flags; |
| } |
| |
| @Override |
| public int getNameTokenCount() { |
| return operand == null ? 2 : 3; |
| } |
| |
| @Override |
| public String getNameToken(final int i) { |
| switch(i) { |
| case 0: return "dyn"; |
| case 1: return operator; |
| case 2: |
| if(operand != null) { |
| return operand; |
| } |
| break; |
| default: |
| break; |
| } |
| throw new IndexOutOfBoundsException(String.valueOf(i)); |
| } |
| |
| @Override |
| public Lookup getLookup() { |
| return lookup; |
| } |
| |
| @Override |
| public boolean equals(final CallSiteDescriptor csd) { |
| return super.equals(csd) && flags == getFlags(csd); |
| } |
| |
| @Override |
| public MethodType getMethodType() { |
| return methodType; |
| } |
| |
| /** |
| * Returns the operator (e.g. {@code "getProp"}) in this call site descriptor's name. Equivalent to |
| * {@code getNameToken(CallSiteDescriptor.OPERATOR)}. The returned operator can be composite. |
| * @return the operator in this call site descriptor's name. |
| */ |
| public String getOperator() { |
| return operator; |
| } |
| |
| /** |
| * Returns the first operator in this call site descriptor's name. E.g. if this call site descriptor has a composite |
| * operation {@code "getProp|getMethod|getElem"}, it will return {@code "getProp"}. 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 "getProp"} and |
| * {@code "getMethod"} being the first operation can translate into whether {@code "__noSuchProperty__"} or |
| * {@code "__noSuchMethod__"} will be executed in case the property is not found. |
| * @return the first operator in this call site descriptor's name. |
| */ |
| public String getFirstOperator() { |
| final int delim = operator.indexOf(CallSiteDescriptor.OPERATOR_DELIMITER); |
| return delim == -1 ? operator : operator.substring(0, delim); |
| } |
| |
| /** |
| * Returns the named operand in this descriptor's name. Equivalent to |
| * {@code getNameToken(CallSiteDescriptor.NAME_OPERAND)}. E.g. for operation {@code "dyn:getProp:color"}, returns |
| * {@code "color"}. For call sites without named operands (e.g. {@code "dyn:new"}) returns null. |
| * @return the named operand in this descriptor's name. |
| */ |
| public String getOperand() { |
| return operand; |
| } |
| |
| /** |
| * If this is a dyn:call or dyn:new, this returns function description from callsite. |
| * Caller has to make sure this is a dyn:call or dyn:new call site. |
| * |
| * @return function description if available (or null) |
| */ |
| public String getFunctionDescription() { |
| assert getFirstOperator().equals("call") || getFirstOperator().equals("new"); |
| return getNameTokenCount() > 2? getNameToken(2) : null; |
| } |
| |
| /** |
| * If this is a dyn:call or dyn:new, this returns function description from callsite. |
| * Caller has to make sure this is a dyn:call or dyn:new call site. |
| * |
| * @param desc call site descriptor |
| * @return function description if available (or null) |
| */ |
| public static String getFunctionDescription(final CallSiteDescriptor desc) { |
| return desc instanceof NashornCallSiteDescriptor ? |
| ((NashornCallSiteDescriptor)desc).getFunctionDescription() : null; |
| } |
| |
| |
| /** |
| * Returns the error message to be used when dyn:call or dyn:new is used on a non-function. |
| * |
| * @param obj object on which dyn:call or dyn:new is used |
| * @return error message |
| */ |
| public String getFunctionErrorMessage(final Object obj) { |
| final String funcDesc = getFunctionDescription(); |
| return funcDesc != null? funcDesc : ScriptRuntime.safeToString(obj); |
| } |
| |
| /** |
| * Returns the error message to be used when dyn:call or dyn:new is used on a non-function. |
| * |
| * @param desc call site descriptor |
| * @param obj object on which dyn:call or dyn: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 changeMethodType(final MethodType newMethodType) { |
| return get(getLookup(), operator, operand, newMethodType, flags); |
| } |
| |
| } |
