jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/codegen/SharedScopeCall.java@bee7c8a45a04 (annotated)

src/jdk/nashorn/internal/codegen/SharedScopeCall.java@bee7c8a45a04 (annotated)

src/jdk/nashorn/internal/codegen/SharedScopeCall.java

Mon, 04 Feb 2013 16:20:05 +0100

author: lagergren
date: Mon, 04 Feb 2013 16:20:05 +0100
changeset 66: bee7c8a45a04
parent 57: 59970b70ebb5
child 89: 43e32b36153c
permissions: -rw-r--r--

8007215: Varargs broken for the case of passing more than the arg limit arguments.
Reviewed-by: jlaskey, attila

 /*
  * 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.codegen;
 import java.util.Arrays;
 import java.util.EnumSet;
 import jdk.nashorn.internal.codegen.types.Type;
 import jdk.nashorn.internal.ir.Symbol;
 import jdk.nashorn.internal.runtime.ScriptObject;
 /**
  * A scope call or get operation that can be shared by several callsites. This generates a static
  * method that wraps the invokedynamic instructions to get or call scope variables.
  * The rationale for this is that initial linking of invokedynamic callsites is expensive,
  * so by sharing them we can reduce startup overhead and allow very large scripts to run that otherwise wouldn't.
  *
  * <p>Static methods generated by this class expect two parameters in addition to the parameters of the
  * function call: The current scope object and the depth of the target scope relative to the scope argument
  * for when this is known at compile-time (fast-scope access).</p>
  *
  * <p>The second argument may be -1 for non-fast-scope symbols, in which case the scope chain is checked
  * for each call. This may cause callsite invalidation when the shared method is used from different
  * scopes, but such sharing of non-fast scope calls may still be necessary for very large scripts.</p>
  *
  * <p>Scope calls must not be shared between normal callsites and callsites contained in a <tt>with</tt>
  * statement as this condition is not handled by current guards and will cause a runtime error.</p>
  */
 public class SharedScopeCall {
     /** Threshold for using shared scope calls with fast scope access. */
     public static final int FAST_SCOPE_CALL_THRESHOLD = 4;
     /** Threshold for using shared scope calls with slow scope access. */
     public static final int SLOW_SCOPE_CALL_THRESHOLD = 500;
     /** Threshold for using shared scope gets with fast scope access. */
     public static final int FAST_SCOPE_GET_THRESHOLD  = 200;
     final Type valueType;
     final Symbol symbol;
     final Type returnType;
     final Type[] paramTypes;
     final int flags;
     final boolean isCall;
     private CompileUnit compileUnit;
     private String methodName;
     private String staticSignature;
     /**
      * Constructor.
      *
      * @param symbol the symbol
      * @param valueType the type of the value
      * @param returnType the return type
      * @param paramTypes the function parameter types
      * @param flags the callsite flags
      */
     SharedScopeCall(final Symbol symbol, final Type valueType, final Type returnType, final Type[] paramTypes, final int flags) {
         this.symbol = symbol;
         this.valueType = valueType;
         this.returnType = returnType;
         this.paramTypes = paramTypes;
         this.flags = flags;
         // If paramTypes is not null this is a call, otherwise it's just a get.
         this.isCall = paramTypes != null;
     }
     @Override
     public int hashCode() {
         return symbol.hashCode() ^ returnType.hashCode() ^ Arrays.hashCode(paramTypes) ^ flags;
     }
     @Override
     public boolean equals(final Object obj) {
         if (obj instanceof SharedScopeCall) {
             final SharedScopeCall c = (SharedScopeCall) obj;
             return symbol.equals(c.symbol)
                     && flags == c.flags
                     && returnType.equals(c.returnType)
                     && Arrays.equals(paramTypes, c.paramTypes);
         }
         return false;
     }
     /**
      * Set the compile unit and method name.
      * @param compileUnit the compile unit
      * @param compiler the compiler to generate a unique method name
      */
     protected void setClassAndName(final CompileUnit compileUnit, final Compiler compiler) {
         this.compileUnit = compileUnit;
         this.methodName = compiler.uniqueName("scopeCall");
     }
     /**
      * Generate the invoke instruction for this shared scope call.
      * @param method the method emitter
      */
     public void generateInvoke(final MethodEmitter method) {
         method.invokeStatic(compileUnit.getUnitClassName(), methodName, getStaticSignature());
     }
     /**
      * Generate the method that implements the scope get or call.
      */
     protected void generateScopeCall() {
         final ClassEmitter classEmitter = compileUnit.getClassEmitter();
         final EnumSet<ClassEmitter.Flag> methodFlags = EnumSet.of(ClassEmitter.Flag.STATIC);
         // This method expects two fixed parameters in addition to any parameters that may be
         // passed on to the function: A ScriptObject representing the caller's current scope object,
         // and an int specifying the distance to the target scope containing the symbol we want to
         // access, or -1 if this is not known at compile time (e.g. because of a "with" or "eval").
         final MethodEmitter method = classEmitter.method(methodFlags, methodName, getStaticSignature());
         method.begin();
         // Load correct scope by calling getProto() on the scope argument as often as specified
         // by the second argument.
         final MethodEmitter.Label parentLoopStart = new MethodEmitter.Label("parent_loop_start");
         final MethodEmitter.Label parentLoopDone = new MethodEmitter.Label("parent_loop_done");
         method.load(Type.OBJECT, 0);
         method.label(parentLoopStart);
         method.load(Type.INT, 1);
         method.iinc(1, -1);
         method.ifle(parentLoopDone);
         method.invoke(ScriptObject.GET_PROTO);
         method._goto(parentLoopStart);
         method.label(parentLoopDone);
         method.dynamicGet(valueType, symbol.getName(), flags, isCall);
         // If this is a get we're done, otherwise call the value as function.
         if (isCall) {
             method.convert(Type.OBJECT);
             // ScriptFunction will see CALLSITE_SCOPE and will bind scope accordingly.
             method.loadNull();
             int slot = 2;
             for (final Type type : paramTypes) {
                 method.load(type, slot++);
                 if (type == Type.NUMBER || type == Type.LONG) {
                     slot++;
                 }
             }
             method.dynamicCall(returnType, 2 + paramTypes.length, flags);
         }
         method._return(returnType);
         method.end();
     }
     private String getStaticSignature() {
         if (staticSignature == null) {
             if (paramTypes == null) {
                 staticSignature = Type.getMethodDescriptor(returnType, Type.typeFor(ScriptObject.class), Type.INT);
             } else {
                 final Type[] params = new Type[paramTypes.length + 2];
                 params[0] = Type.typeFor(ScriptObject.class);
                 params[1] = Type.INT;
                 int i = 2;
                 for (Type type : paramTypes)  {
                     if (type.isObject()) {
                         type = Type.OBJECT;
                     }
                     params[i++] = type;
                 }
                 staticSignature = Type.getMethodDescriptor(returnType, params);
             }
         }
         return staticSignature;
     }
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/codegen/SharedScopeCall.java@bee7c8a45a04 (annotated)

src/jdk/nashorn/internal/codegen/SharedScopeCall.java