/*
 * 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
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package jdk.nashorn.internal.ir.debug;

import java.util.List;
import jdk.nashorn.internal.ir.BinaryNode;
import jdk.nashorn.internal.ir.Block;
import jdk.nashorn.internal.ir.BlockStatement;
import jdk.nashorn.internal.ir.BreakNode;
import jdk.nashorn.internal.ir.CaseNode;
import jdk.nashorn.internal.ir.CatchNode;
import jdk.nashorn.internal.ir.ContinueNode;
import jdk.nashorn.internal.ir.ExpressionStatement;
import jdk.nashorn.internal.ir.ForNode;
import jdk.nashorn.internal.ir.FunctionNode;
import jdk.nashorn.internal.ir.IdentNode;
import jdk.nashorn.internal.ir.IfNode;
import jdk.nashorn.internal.ir.JoinPredecessor;
import jdk.nashorn.internal.ir.JoinPredecessorExpression;
import jdk.nashorn.internal.ir.LabelNode;
import jdk.nashorn.internal.ir.LocalVariableConversion;
import jdk.nashorn.internal.ir.Node;
import jdk.nashorn.internal.ir.SplitNode;
import jdk.nashorn.internal.ir.Statement;
import jdk.nashorn.internal.ir.SwitchNode;
import jdk.nashorn.internal.ir.ThrowNode;
import jdk.nashorn.internal.ir.TryNode;
import jdk.nashorn.internal.ir.UnaryNode;
import jdk.nashorn.internal.ir.VarNode;
import jdk.nashorn.internal.ir.WhileNode;
import jdk.nashorn.internal.ir.WithNode;
import jdk.nashorn.internal.ir.visitor.SimpleNodeVisitor;

Print out the AST as human readable source code. This works both on lowered and unlowered ASTs see the flags --print-parse and --print-lower-parse
/** * Print out the AST as human readable source code. * This works both on lowered and unlowered ASTs * * see the flags --print-parse and --print-lower-parse */
public final class PrintVisitor extends SimpleNodeVisitor {
Tab width
/** Tab width */
private static final int TABWIDTH = 4;
Composing buffer.
/** Composing buffer. */
private final StringBuilder sb;
Indentation factor.
/** Indentation factor. */
private int indent;
Line separator.
/** Line separator. */
private final String EOLN;
Print line numbers
/** Print line numbers */
private final boolean printLineNumbers;
Print inferred and optimistic types
/** Print inferred and optimistic types */
private final boolean printTypes; private int lastLineNumber = -1;
Constructor.
/** * Constructor. */
public PrintVisitor() { this(true, true); }
Constructor
Params:
  • printLineNumbers – should line number nodes be included in the output?
  • printTypes – should we print optimistic and inferred types?
/** * Constructor * * @param printLineNumbers should line number nodes be included in the output? * @param printTypes should we print optimistic and inferred types? */
public PrintVisitor(final boolean printLineNumbers, final boolean printTypes) { this.EOLN = System.lineSeparator(); this.sb = new StringBuilder(); this.printLineNumbers = printLineNumbers; this.printTypes = printTypes; }
Constructor
Params:
  • root – a node from which to start printing code
/** * Constructor * * @param root a node from which to start printing code */
public PrintVisitor(final Node root) { this(root, true, true); }
Constructor
Params:
  • root – a node from which to start printing code
  • printLineNumbers – should line numbers nodes be included in the output?
  • printTypes – should we print optimistic and inferred types?
/** * Constructor * * @param root a node from which to start printing code * @param printLineNumbers should line numbers nodes be included in the output? * @param printTypes should we print optimistic and inferred types? */
public PrintVisitor(final Node root, final boolean printLineNumbers, final boolean printTypes) { this(printLineNumbers, printTypes); visit(root); } private void visit(final Node root) { root.accept(this); } @Override public String toString() { return sb.append(EOLN).toString(); }
Insert spaces before a statement.
/** * Insert spaces before a statement. */
private void indent() { for (int i = indent; i > 0; i--) { sb.append(' '); } } /* * Visits. */ @Override public boolean enterDefault(final Node node) { node.toString(sb, printTypes); return false; } @Override public boolean enterContinueNode(final ContinueNode node) { node.toString(sb, printTypes); printLocalVariableConversion(node); return false; } @Override public boolean enterBreakNode(final BreakNode node) { node.toString(sb, printTypes); printLocalVariableConversion(node); return false; } @Override public boolean enterThrowNode(final ThrowNode node) { node.toString(sb, printTypes); printLocalVariableConversion(node); return false; } @Override public boolean enterBlock(final Block block) { sb.append(' '); sb.append('{'); indent += TABWIDTH; final List<Statement> statements = block.getStatements(); for (final Statement statement : statements) { if (printLineNumbers) { final int lineNumber = statement.getLineNumber(); sb.append('\n'); if (lineNumber != lastLineNumber) { indent(); sb.append("[|").append(lineNumber).append("|];").append('\n'); } lastLineNumber = lineNumber; } indent(); statement.accept(this); int lastIndex = sb.length() - 1; char lastChar = sb.charAt(lastIndex); while (Character.isWhitespace(lastChar) && lastIndex >= 0) { lastChar = sb.charAt(--lastIndex); } if (lastChar != '}' && lastChar != ';') { sb.append(';'); } if (statement.hasGoto()) { sb.append(" [GOTO]"); } if (statement.isTerminal()) { sb.append(" [TERMINAL]"); } } indent -= TABWIDTH; sb.append(EOLN); indent(); sb.append('}'); printLocalVariableConversion(block); return false; } @Override public boolean enterBlockStatement(final BlockStatement statement) { statement.getBlock().accept(this); return false; } @Override public boolean enterBinaryNode(final BinaryNode binaryNode) { binaryNode.lhs().accept(this); sb.append(' '); sb.append(binaryNode.tokenType()); sb.append(' '); binaryNode.rhs().accept(this); return false; } @Override public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression expr) { expr.getExpression().accept(this); printLocalVariableConversion(expr); return false; } @Override public boolean enterIdentNode(final IdentNode identNode) { identNode.toString(sb, printTypes); printLocalVariableConversion(identNode); return true; } private void printLocalVariableConversion(final JoinPredecessor joinPredecessor) { LocalVariableConversion.toString(joinPredecessor.getLocalVariableConversion(), sb); } @Override public boolean enterUnaryNode(final UnaryNode unaryNode) { unaryNode.toString(sb, new Runnable() { @Override public void run() { unaryNode.getExpression().accept(PrintVisitor.this); } }, printTypes); return false; } @Override public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) { expressionStatement.getExpression().accept(this); return false; } @Override public boolean enterForNode(final ForNode forNode) { forNode.toString(sb, printTypes); forNode.getBody().accept(this); return false; } @Override public boolean enterFunctionNode(final FunctionNode functionNode) { functionNode.toString(sb, printTypes); enterBlock(functionNode.getBody()); return false; } @Override public boolean enterIfNode(final IfNode ifNode) { ifNode.toString(sb, printTypes); ifNode.getPass().accept(this); final Block fail = ifNode.getFail(); if (fail != null) { sb.append(" else "); fail.accept(this); } if(ifNode.getLocalVariableConversion() != null) { assert fail == null; sb.append(" else "); printLocalVariableConversion(ifNode); sb.append(";"); } return false; } @Override public boolean enterLabelNode(final LabelNode labeledNode) { indent -= TABWIDTH; indent(); indent += TABWIDTH; labeledNode.toString(sb, printTypes); labeledNode.getBody().accept(this); printLocalVariableConversion(labeledNode); return false; } @Override public boolean enterSplitNode(final SplitNode splitNode) { splitNode.toString(sb, printTypes); sb.append(EOLN); indent += TABWIDTH; indent(); return true; } @Override public Node leaveSplitNode(final SplitNode splitNode) { sb.append("</split>"); sb.append(EOLN); indent -= TABWIDTH; indent(); return splitNode; } @Override public boolean enterSwitchNode(final SwitchNode switchNode) { switchNode.toString(sb, printTypes); sb.append(" {"); final List<CaseNode> cases = switchNode.getCases(); for (final CaseNode caseNode : cases) { sb.append(EOLN); indent(); caseNode.toString(sb, printTypes); printLocalVariableConversion(caseNode); indent += TABWIDTH; caseNode.getBody().accept(this); indent -= TABWIDTH; sb.append(EOLN); } if(switchNode.getLocalVariableConversion() != null) { sb.append(EOLN); indent(); sb.append("default: "); printLocalVariableConversion(switchNode); sb.append("{}"); } sb.append(EOLN); indent(); sb.append("}"); return false; } @Override public boolean enterTryNode(final TryNode tryNode) { tryNode.toString(sb, printTypes); printLocalVariableConversion(tryNode); tryNode.getBody().accept(this); final List<Block> catchBlocks = tryNode.getCatchBlocks(); for (final Block catchBlock : catchBlocks) { final CatchNode catchNode = (CatchNode)catchBlock.getStatements().get(0); catchNode.toString(sb, printTypes); catchNode.getBody().accept(this); } final Block finallyBody = tryNode.getFinallyBody(); if (finallyBody != null) { sb.append(" finally "); finallyBody.accept(this); } for (final Block inlinedFinally : tryNode.getInlinedFinallies()) { inlinedFinally.accept(this); } return false; } @Override public boolean enterVarNode(final VarNode varNode) { sb.append(varNode.isConst() ? "const " : varNode.isLet() ? "let " : "var "); varNode.getName().toString(sb, printTypes); printLocalVariableConversion(varNode.getName()); final Node init = varNode.getInit(); if (init != null) { sb.append(" = "); init.accept(this); } return false; } @Override public boolean enterWhileNode(final WhileNode whileNode) { printLocalVariableConversion(whileNode); if (whileNode.isDoWhile()) { sb.append("do"); whileNode.getBody().accept(this); sb.append(' '); whileNode.toString(sb, printTypes); } else { whileNode.toString(sb, printTypes); whileNode.getBody().accept(this); } return false; } @Override public boolean enterWithNode(final WithNode withNode) { withNode.toString(sb, printTypes); withNode.getBody().accept(this); return false; } }