src/main/java/com/puppycrawl/tools/checkstyle/AstTreeStringPrinter.java - platform/external/checkstyle - Git at Google

 ////////////////////////////////////////////////////////////////////////////////
 // checkstyle: Checks Java source code for adherence to a set of rules.
 // Copyright (C) 2001-2017 the original author or authors.
 //
 // This library is free software; you can redistribute it and/or
 // modify it under the terms of the GNU Lesser General Public
 // License as published by the Free Software Foundation; either
 // version 2.1 of the License, or (at your option) any later version.
 //
 // This library 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
 // Lesser General Public License for more details.
 //
 // You should have received a copy of the GNU Lesser General Public
 // License along with this library; if not, write to the Free Software
 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 ////////////////////////////////////////////////////////////////////////////////

 package com.puppycrawl.tools.checkstyle;

 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Locale;
 import java.util.regex.Pattern;

 import antlr.RecognitionException;
 import antlr.TokenStreamException;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.DetailNode;
 import com.puppycrawl.tools.checkstyle.api.FileContents;
 import com.puppycrawl.tools.checkstyle.api.FileText;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;
 import com.puppycrawl.tools.checkstyle.utils.TokenUtils;

 /**
  * Class for printing AST to String.
  * @author Vladislav Lisetskii
  */
 public final class AstTreeStringPrinter {

     /**
      * Enum to be used for test if comments should be printed.
      */
     public enum PrintOptions {
         /**
          * Comments has to be printed.
          */
         WITH_COMMENTS,
         /**
          * Comments has NOT to be printed.
          */
         WITHOUT_COMMENTS
     }

     /** Newline pattern. */
     private static final Pattern NEWLINE = Pattern.compile("\n");
     /** Return pattern. */
     private static final Pattern RETURN = Pattern.compile("\r");
     /** Tab pattern. */
     private static final Pattern TAB = Pattern.compile("\t");

     /** OS specific line separator. */
     private static final String LINE_SEPARATOR = System.getProperty("line.separator");

     /** Prevent instances. */
     private AstTreeStringPrinter() {
         // no code
     }

     /**
      * Parse a file and print the parse tree.
      * @param file the file to print.
      * @param withComments true to include comments to AST
      * @return the AST of the file in String form.
      * @throws IOException if the file could not be read.
      * @throws CheckstyleException if the file is not a Java source.
      */
     public static String printFileAst(File file, PrintOptions withComments)
             throws IOException, CheckstyleException {
         return printTree(parseFile(file, withComments));
     }

     /**
      * Prints full AST (java + comments + javadoc) of the java file.
      * @param file java file
      * @return Full tree
      * @throws IOException Failed to open a file
      * @throws CheckstyleException error while parsing the file
      */
     public static String printJavaAndJavadocTree(File file)
             throws IOException, CheckstyleException {
         final DetailAST tree = parseFile(file, PrintOptions.WITH_COMMENTS);
         return printJavaAndJavadocTree(tree);
     }

     /**
      * Prints full tree (java + comments + javadoc) of the DetailAST.
      * @param ast root DetailAST
      * @return Full tree
      */
     private static String printJavaAndJavadocTree(DetailAST ast) {
         final StringBuilder messageBuilder = new StringBuilder(1024);
         DetailAST node = ast;
         while (node != null) {
             messageBuilder.append(getIndentation(node))
                 .append(getNodeInfo(node))
                 .append(LINE_SEPARATOR);
             if (node.getType() == TokenTypes.COMMENT_CONTENT
                     && JavadocUtils.isJavadocComment(node.getParent())) {
                 final String javadocTree = parseAndPrintJavadocTree(node);
                 messageBuilder.append(javadocTree);
             }
             else {
                 messageBuilder.append(printJavaAndJavadocTree(node.getFirstChild()));
             }
             node = node.getNextSibling();
         }
         return messageBuilder.toString();
     }

     /**
      * Parses block comment as javadoc and prints its tree.
      * @param node block comment begin
      * @return string javadoc tree
      */
     private static String parseAndPrintJavadocTree(DetailAST node) {
         final DetailAST javadocBlock = node.getParent();
         final DetailNode tree = DetailNodeTreeStringPrinter.parseJavadocAsDetailNode(javadocBlock);

         String baseIndentation = getIndentation(node);
         baseIndentation = baseIndentation.substring(0, baseIndentation.length() - 2);
         final String rootPrefix = baseIndentation + "   `--";
         final String prefix = baseIndentation + "       ";
         return DetailNodeTreeStringPrinter.printTree(tree, rootPrefix, prefix);
     }

     /**
      * Parse a file and print the parse tree.
      * @param text the text to parse.
      * @param withComments true to include comments to AST
      * @return the AST of the file in String form.
      * @throws CheckstyleException if the file is not a Java source.
      */
     public static String printAst(FileText text,
                                   PrintOptions withComments) throws CheckstyleException {
         return printTree(parseFileText(text, withComments));
     }

     /**
      * Print AST.
      * @param ast the root AST node.
      * @return string AST.
      */
     private static String printTree(DetailAST ast) {
         final StringBuilder messageBuilder = new StringBuilder(1024);
         DetailAST node = ast;
         while (node != null) {
             messageBuilder.append(getIndentation(node))
                     .append(getNodeInfo(node))
                     .append(LINE_SEPARATOR)
                     .append(printTree(node.getFirstChild()));
             node = node.getNextSibling();
         }
         return messageBuilder.toString();
     }

     /**
      * Get string representation of the node as token name,
      * node text, line number and column number.
      * @param node DetailAST
      * @return node info
      */
     private static String getNodeInfo(DetailAST node) {
         return TokenUtils.getTokenName(node.getType())
                 + " -> " + escapeAllControlChars(node.getText())
                 + " [" + node.getLineNo() + ':' + node.getColumnNo() + ']';
     }

     /**
      * Get indentation for an AST node.
      * @param ast the AST to get the indentation for.
      * @return the indentation in String format.
      */
     private static String getIndentation(DetailAST ast) {
         final boolean isLastChild = ast.getNextSibling() == null;
         DetailAST node = ast;
         final StringBuilder indentation = new StringBuilder(1024);
         while (node.getParent() != null) {
             node = node.getParent();
             if (node.getParent() == null) {
                 if (isLastChild) {
                     // only ASCII symbols must be used due to
                     // problems with running tests on Windows
                     indentation.append("`--");
                 }
                 else {
                     indentation.append("|--");
                 }
             }
             else {
                 if (node.getNextSibling() == null) {
                     indentation.insert(0, "    ");
                 }
                 else {
                     indentation.insert(0, "|   ");
                 }
             }
         }
         return indentation.toString();
     }

     /**
      * Replace all control chars with escaped symbols.
      * @param text the String to process.
      * @return the processed String with all control chars escaped.
      */
     private static String escapeAllControlChars(String text) {
         final String textWithoutNewlines = NEWLINE.matcher(text).replaceAll("\\\\n");
         final String textWithoutReturns = RETURN.matcher(textWithoutNewlines).replaceAll("\\\\r");
         return TAB.matcher(textWithoutReturns).replaceAll("\\\\t");
     }

     /**
      * Parse a file and return the parse tree.
      * @param file the file to parse.
      * @param withComments true to include comment nodes to the tree
      * @return the root node of the parse tree.
      * @throws IOException if the file could not be read.
      * @throws CheckstyleException if the file is not a Java source.
      */
     private static DetailAST parseFile(File file, PrintOptions withComments)
             throws IOException, CheckstyleException {
         final FileText text = new FileText(file.getAbsoluteFile(),
             System.getProperty("file.encoding", StandardCharsets.UTF_8.name()));
         return parseFileText(text, withComments);
     }

     /**
      * Parse a text and return the parse tree.
      * @param text the text to parse.
      * @param withComments true to include comment nodes to the tree
      * @return the root node of the parse tree.
      * @throws CheckstyleException if the file is not a Java source.
      */
     private static DetailAST parseFileText(FileText text, PrintOptions withComments)
             throws CheckstyleException {
         final FileContents contents = new FileContents(text);
         final DetailAST result;
         try {
             if (withComments == PrintOptions.WITH_COMMENTS) {
                 result = TreeWalker.parseWithComments(contents);
             }
             else {
                 result = TreeWalker.parse(contents);
             }
         }
         catch (RecognitionException | TokenStreamException ex) {
             final String exceptionMsg = String.format(Locale.ROOT,
                 "%s occurred during the analysis of file %s.",
                 ex.getClass().getSimpleName(), text.getFile().getPath());
             throw new CheckstyleException(exceptionMsg, ex);
         }

         return result;
     }
 }
	////////////////////////////////////////////////////////////////////////////////
	// checkstyle: Checks Java source code for adherence to a set of rules.
	// Copyright (C) 2001-2017 the original author or authors.
	//
	// This library is free software; you can redistribute it and/or
	// modify it under the terms of the GNU Lesser General Public
	// License as published by the Free Software Foundation; either
	// version 2.1 of the License, or (at your option) any later version.
	//
	// This library 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
	// Lesser General Public License for more details.
	//
	// You should have received a copy of the GNU Lesser General Public
	// License along with this library; if not, write to the Free Software
	// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	////////////////////////////////////////////////////////////////////////////////

	package com.puppycrawl.tools.checkstyle;

	import java.io.File;
	import java.io.IOException;
	import java.nio.charset.StandardCharsets;
	import java.util.Locale;
	import java.util.regex.Pattern;

	import antlr.RecognitionException;
	import antlr.TokenStreamException;
	import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
	import com.puppycrawl.tools.checkstyle.api.DetailAST;
	import com.puppycrawl.tools.checkstyle.api.DetailNode;
	import com.puppycrawl.tools.checkstyle.api.FileContents;
	import com.puppycrawl.tools.checkstyle.api.FileText;
	import com.puppycrawl.tools.checkstyle.api.TokenTypes;
	import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;
	import com.puppycrawl.tools.checkstyle.utils.TokenUtils;

	/**
	* Class for printing AST to String.
	* @author Vladislav Lisetskii
	*/
	public final class AstTreeStringPrinter {

	/**
	* Enum to be used for test if comments should be printed.
	*/
	public enum PrintOptions {
	/**
	* Comments has to be printed.
	*/
	WITH_COMMENTS,
	/**
	* Comments has NOT to be printed.
	*/
	WITHOUT_COMMENTS
	}

	/** Newline pattern. */
	private static final Pattern NEWLINE = Pattern.compile("\n");
	/** Return pattern. */
	private static final Pattern RETURN = Pattern.compile("\r");
	/** Tab pattern. */
	private static final Pattern TAB = Pattern.compile("\t");

	/** OS specific line separator. */
	private static final String LINE_SEPARATOR = System.getProperty("line.separator");

	/** Prevent instances. */
	private AstTreeStringPrinter() {
	// no code
	}

	/**
	* Parse a file and print the parse tree.
	* @param file the file to print.
	* @param withComments true to include comments to AST
	* @return the AST of the file in String form.
	* @throws IOException if the file could not be read.
	* @throws CheckstyleException if the file is not a Java source.
	*/
	public static String printFileAst(File file, PrintOptions withComments)
	throws IOException, CheckstyleException {
	return printTree(parseFile(file, withComments));
	}

	/**
	* Prints full AST (java + comments + javadoc) of the java file.
	* @param file java file
	* @return Full tree
	* @throws IOException Failed to open a file
	* @throws CheckstyleException error while parsing the file
	*/
	public static String printJavaAndJavadocTree(File file)
	throws IOException, CheckstyleException {
	final DetailAST tree = parseFile(file, PrintOptions.WITH_COMMENTS);
	return printJavaAndJavadocTree(tree);
	}

	/**
	* Prints full tree (java + comments + javadoc) of the DetailAST.
	* @param ast root DetailAST
	* @return Full tree
	*/
	private static String printJavaAndJavadocTree(DetailAST ast) {
	final StringBuilder messageBuilder = new StringBuilder(1024);
	DetailAST node = ast;
	while (node != null) {
	messageBuilder.append(getIndentation(node))
	.append(getNodeInfo(node))
	.append(LINE_SEPARATOR);
	if (node.getType() == TokenTypes.COMMENT_CONTENT
	&& JavadocUtils.isJavadocComment(node.getParent())) {
	final String javadocTree = parseAndPrintJavadocTree(node);
	messageBuilder.append(javadocTree);
	}
	else {
	messageBuilder.append(printJavaAndJavadocTree(node.getFirstChild()));
	}
	node = node.getNextSibling();
	}
	return messageBuilder.toString();
	}

	/**
	* Parses block comment as javadoc and prints its tree.
	* @param node block comment begin
	* @return string javadoc tree
	*/
	private static String parseAndPrintJavadocTree(DetailAST node) {
	final DetailAST javadocBlock = node.getParent();
	final DetailNode tree = DetailNodeTreeStringPrinter.parseJavadocAsDetailNode(javadocBlock);

	String baseIndentation = getIndentation(node);
	baseIndentation = baseIndentation.substring(0, baseIndentation.length() - 2);
	final String rootPrefix = baseIndentation + " `--";
	final String prefix = baseIndentation + " ";
	return DetailNodeTreeStringPrinter.printTree(tree, rootPrefix, prefix);
	}

	/**
	* Parse a file and print the parse tree.
	* @param text the text to parse.
	* @param withComments true to include comments to AST
	* @return the AST of the file in String form.
	* @throws CheckstyleException if the file is not a Java source.
	*/
	public static String printAst(FileText text,
	PrintOptions withComments) throws CheckstyleException {
	return printTree(parseFileText(text, withComments));
	}

	/**
	* Print AST.
	* @param ast the root AST node.
	* @return string AST.
	*/
	private static String printTree(DetailAST ast) {
	final StringBuilder messageBuilder = new StringBuilder(1024);
	DetailAST node = ast;
	while (node != null) {
	messageBuilder.append(getIndentation(node))
	.append(getNodeInfo(node))
	.append(LINE_SEPARATOR)
	.append(printTree(node.getFirstChild()));
	node = node.getNextSibling();
	}
	return messageBuilder.toString();
	}

	/**
	* Get string representation of the node as token name,
	* node text, line number and column number.
	* @param node DetailAST
	* @return node info
	*/
	private static String getNodeInfo(DetailAST node) {
	return TokenUtils.getTokenName(node.getType())
	+ " -> " + escapeAllControlChars(node.getText())
	+ " [" + node.getLineNo() + ':' + node.getColumnNo() + ']';
	}

	/**
	* Get indentation for an AST node.
	* @param ast the AST to get the indentation for.
	* @return the indentation in String format.
	*/
	private static String getIndentation(DetailAST ast) {
	final boolean isLastChild = ast.getNextSibling() == null;
	DetailAST node = ast;
	final StringBuilder indentation = new StringBuilder(1024);
	while (node.getParent() != null) {
	node = node.getParent();
	if (node.getParent() == null) {
	if (isLastChild) {
	// only ASCII symbols must be used due to
	// problems with running tests on Windows
	indentation.append("`--");
	}
	else {
	indentation.append("\|--");
	}
	}
	else {
	if (node.getNextSibling() == null) {
	indentation.insert(0, " ");
	}
	else {
	indentation.insert(0, "\| ");
	}
	}
	}
	return indentation.toString();
	}

	/**
	* Replace all control chars with escaped symbols.
	* @param text the String to process.
	* @return the processed String with all control chars escaped.
	*/
	private static String escapeAllControlChars(String text) {
	final String textWithoutNewlines = NEWLINE.matcher(text).replaceAll("\\\\n");
	final String textWithoutReturns = RETURN.matcher(textWithoutNewlines).replaceAll("\\\\r");
	return TAB.matcher(textWithoutReturns).replaceAll("\\\\t");
	}

	/**
	* Parse a file and return the parse tree.
	* @param file the file to parse.
	* @param withComments true to include comment nodes to the tree
	* @return the root node of the parse tree.
	* @throws IOException if the file could not be read.
	* @throws CheckstyleException if the file is not a Java source.
	*/
	private static DetailAST parseFile(File file, PrintOptions withComments)
	throws IOException, CheckstyleException {
	final FileText text = new FileText(file.getAbsoluteFile(),
	System.getProperty("file.encoding", StandardCharsets.UTF_8.name()));
	return parseFileText(text, withComments);
	}

	/**
	* Parse a text and return the parse tree.
	* @param text the text to parse.
	* @param withComments true to include comment nodes to the tree
	* @return the root node of the parse tree.
	* @throws CheckstyleException if the file is not a Java source.
	*/
	private static DetailAST parseFileText(FileText text, PrintOptions withComments)
	throws CheckstyleException {
	final FileContents contents = new FileContents(text);
	final DetailAST result;
	try {
	if (withComments == PrintOptions.WITH_COMMENTS) {
	result = TreeWalker.parseWithComments(contents);
	}
	else {
	result = TreeWalker.parse(contents);
	}
	}
	catch (RecognitionException \| TokenStreamException ex) {
	final String exceptionMsg = String.format(Locale.ROOT,
	"%s occurred during the analysis of file %s.",
	ex.getClass().getSimpleName(), text.getFile().getPath());
	throw new CheckstyleException(exceptionMsg, ex);
	}

	return result;
	}
	}