Mercurial > hg > shenandoah-preopenjdk-archive > openjdk8 > nashorn
view src/jdk/nashorn/internal/ir/SwitchNode.java @ 1060:8c51767d534d
8059843: Make AST serializable
Reviewed-by: hannesw, lagergren
author | attila |
---|---|
date | Fri, 17 Oct 2014 14:24:26 +0200 |
parents | e2497b11a021 |
children |
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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.ir; import java.util.ArrayList; import java.util.Collections; import java.util.List; import jdk.nashorn.internal.codegen.Label; import jdk.nashorn.internal.ir.annotations.Immutable; import jdk.nashorn.internal.ir.visitor.NodeVisitor; /** * IR representation of a SWITCH statement. */ @Immutable public final class SwitchNode extends BreakableStatement { private static final long serialVersionUID = 1L; /** Switch expression. */ private final Expression expression; /** Switch cases. */ private final List<CaseNode> cases; /** Switch default index. */ private final int defaultCaseIndex; /** Tag symbol. */ private Symbol tag; /** * Constructor * * @param lineNumber lineNumber * @param token token * @param finish finish * @param expression switch expression * @param cases cases * @param defaultCase the default case node - null if none, otherwise has to be present in cases list */ public SwitchNode(final int lineNumber, final long token, final int finish, final Expression expression, final List<CaseNode> cases, final CaseNode defaultCase) { super(lineNumber, token, finish, new Label("switch_break")); this.expression = expression; this.cases = cases; this.defaultCaseIndex = defaultCase == null ? -1 : cases.indexOf(defaultCase); } private SwitchNode(final SwitchNode switchNode, final Expression expression, final List<CaseNode> cases, final int defaultCaseIndex, final LocalVariableConversion conversion) { super(switchNode, conversion); this.expression = expression; this.cases = cases; this.defaultCaseIndex = defaultCaseIndex; this.tag = switchNode.getTag(); //TODO are symbols inhereted as references? } @Override public Node ensureUniqueLabels(final LexicalContext lc) { final List<CaseNode> newCases = new ArrayList<>(); for (final CaseNode caseNode : cases) { newCases.add(new CaseNode(caseNode, caseNode.getTest(), caseNode.getBody(), caseNode.getLocalVariableConversion())); } return Node.replaceInLexicalContext(lc, this, new SwitchNode(this, expression, newCases, defaultCaseIndex, conversion)); } @Override public boolean isTerminal() { //there must be a default case, and that including all other cases must terminate if (!cases.isEmpty() && defaultCaseIndex != -1) { for (final CaseNode caseNode : cases) { if (!caseNode.isTerminal()) { return false; } } return true; } return false; } @Override public Node accept(final LexicalContext lc, final NodeVisitor<? extends LexicalContext> visitor) { if (visitor.enterSwitchNode(this)) { return visitor.leaveSwitchNode( setExpression(lc, (Expression)expression.accept(visitor)). setCases(lc, Node.accept(visitor, cases), defaultCaseIndex)); } return this; } @Override public void toString(final StringBuilder sb, final boolean printType) { sb.append("switch ("); expression.toString(sb, printType); sb.append(')'); } /** * Return the case node that is default case * @return default case or null if none */ public CaseNode getDefaultCase() { return defaultCaseIndex == -1 ? null : cases.get(defaultCaseIndex); } /** * Get the cases in this switch * @return a list of case nodes */ public List<CaseNode> getCases() { return Collections.unmodifiableList(cases); } /** * Replace case nodes with new list. the cases have to be the same * and the default case index the same. This is typically used * by NodeVisitors who perform operations on every case node * @param lc lexical context * @param cases list of cases * @return new switch node or same if no state was changed */ public SwitchNode setCases(final LexicalContext lc, final List<CaseNode> cases) { return setCases(lc, cases, defaultCaseIndex); } private SwitchNode setCases(final LexicalContext lc, final List<CaseNode> cases, final int defaultCaseIndex) { if (this.cases == cases) { return this; } return Node.replaceInLexicalContext(lc, this, new SwitchNode(this, expression, cases, defaultCaseIndex, conversion)); } /** * Set or reset the list of cases in this switch * @param lc lexical context * @param cases a list of cases, case nodes * @param defaultCase a case in the list that is the default - must be in the list or class will assert * @return new switch node or same if no state was changed */ public SwitchNode setCases(final LexicalContext lc, final List<CaseNode> cases, final CaseNode defaultCase) { return setCases(lc, cases, defaultCase == null ? -1 : cases.indexOf(defaultCase)); } /** * Return the expression to switch on * @return switch expression */ public Expression getExpression() { return expression; } /** * Set or reset the expression to switch on * @param lc lexical context * @param expression switch expression * @return new switch node or same if no state was changed */ public SwitchNode setExpression(final LexicalContext lc, final Expression expression) { if (this.expression == expression) { return this; } return Node.replaceInLexicalContext(lc, this, new SwitchNode(this, expression, cases, defaultCaseIndex, conversion)); } /** * Get the tag symbol for this switch. The tag symbol is where * the switch expression result is stored * @return tag symbol */ public Symbol getTag() { return tag; } /** * Set the tag symbol for this switch. The tag symbol is where * the switch expression result is stored * @param tag a symbol */ public void setTag(final Symbol tag) { this.tag = tag; } /** * Returns true if all cases of this switch statement are 32-bit signed integer constants. * @return true if all cases of this switch statement are 32-bit signed integer constants. */ public boolean isInteger() { for (final CaseNode caseNode : cases) { final Expression test = caseNode.getTest(); if (test != null && !isIntegerLiteral(test)) { return false; } } return true; } @Override JoinPredecessor setLocalVariableConversionChanged(final LexicalContext lc, final LocalVariableConversion conversion) { return Node.replaceInLexicalContext(lc, this, new SwitchNode(this, expression, cases, defaultCaseIndex, conversion)); } private static boolean isIntegerLiteral(final Expression expr) { return expr instanceof LiteralNode && ((LiteralNode<?>)expr).getValue() instanceof Integer; } }