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/*
* 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.ArrayList;
import java.util.List;
import static jdk.nashorn.internal.codegen.CompilerConstants.SCOPE;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.nashorn.internal.codegen.types.Type;
import jdk.nashorn.internal.ir.LexicalContext;
import jdk.nashorn.internal.ir.SplitNode;
import jdk.nashorn.internal.runtime.Scope;
/**
* Emitter used for splitting methods. Needs to keep track of if there are jump targets
* outside the current split node. All external jump targets encountered at method
* emission are logged, and {@code CodeGenerator#leaveSplitNode(SplitNode)} creates
* an appropriate jump table when the SplitNode has been iterated through
*/
public class SplitMethodEmitter extends MethodEmitter {
private final SplitNode splitNode;
private final List<Label> externalTargets = new ArrayList<>();
SplitMethodEmitter(final ClassEmitter classEmitter, final MethodVisitor mv, SplitNode splitNode) {
super(classEmitter, mv);
this.splitNode = splitNode;
}
@Override
void splitAwareGoto(final LexicalContext lc, final Label label) {
assert splitNode != null;
final int index = findExternalTarget(lc, label);
if (index >= 0) {
loadCompilerConstant(SCOPE);
checkcast(Scope.class);
load(index + 1);
invoke(Scope.SET_SPLIT_STATE);
loadUndefined(Type.OBJECT);
_return(functionNode.getReturnType());
return;
}
super.splitAwareGoto(lc, label);
}
private int findExternalTarget(final LexicalContext lc, final Label label) {
final int index = externalTargets.indexOf(label);
if (index >= 0) {
return index;
}
if (lc.isExternalTarget(splitNode, label)) {
externalTargets.add(label);
return externalTargets.size() - 1;
}
return -1;
}
@Override
MethodEmitter registerReturn() {
super.registerReturn();
loadCompilerConstant(SCOPE);
checkcast(Scope.class);
load(0);
invoke(Scope.SET_SPLIT_STATE);
return this;
}
@Override
final List<Label> getExternalTargets() {
return externalTargets;
}
}
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