////////////////////////////////////////////////////////////////////////////////
// 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 org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.BailErrorStrategy;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.misc.ParseCancellationException;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.runtime.tree.TerminalNode;
import com.google.common.base.CaseFormat;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.DetailNode;
import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
import com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocNodeImpl;
import com.puppycrawl.tools.checkstyle.grammars.javadoc.JavadocLexer;
import com.puppycrawl.tools.checkstyle.grammars.javadoc.JavadocParser;
import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;
/**
* Used for parsing Javadoc comment as DetailNode tree.
* @author bizmailov
*
*/
public class JavadocDetailNodeParser {
/**
* Message key of error message. Missed close HTML tag breaks structure
* of parse tree, so parser stops parsing and generates such error
* message. This case is special because parser prints error like
* {@code "no viable alternative at input 'b \n *\n'"} and it is not
* clear that error is about missed close HTML tag.
*/
public static final String MSG_JAVADOC_MISSED_HTML_CLOSE = "javadoc.missed.html.close";
/**
* Message key of error message.
*/
public static final String MSG_JAVADOC_WRONG_SINGLETON_TAG =
"javadoc.wrong.singleton.html.tag";
/**
* Parse error while rule recognition.
*/
public static final String MSG_JAVADOC_PARSE_RULE_ERROR = "javadoc.parse.rule.error";
/**
* Error message key for common javadoc errors.
*/
public static final String MSG_KEY_PARSE_ERROR = "javadoc.parse.error";
/**
* Unrecognized error from antlr parser.
*/
public static final String MSG_KEY_UNRECOGNIZED_ANTLR_ERROR =
"javadoc.unrecognized.antlr.error";
/** Symbols with which javadoc starts. */
private static final String JAVADOC_START = "/**";
/**
* Line number of the Block comment AST that is being parsed.
*/
private int blockCommentLineNumber;
/**
* Custom error listener.
*/
private DescriptiveErrorListener errorListener;
/**
* Parses Javadoc comment as DetailNode tree.
* @param javadocCommentAst
* DetailAST of Javadoc comment
* @return DetailNode tree of Javadoc comment
*/
public ParseStatus parseJavadocAsDetailNode(DetailAST javadocCommentAst) {
blockCommentLineNumber = javadocCommentAst.getLineNo();
final String javadocComment = JavadocUtils.getJavadocCommentContent(javadocCommentAst);
// Use a new error listener each time to be able to use
// one check instance for multiple files to be checked
// without getting side effects.
errorListener = new DescriptiveErrorListener();
// Log messages should have line number in scope of file,
// not in scope of Javadoc comment.
// Offset is line number of beginning of Javadoc comment.
errorListener.setOffset(javadocCommentAst.getLineNo() - 1);
final ParseStatus result = new ParseStatus();
try {
final ParseTree parseTree = parseJavadocAsParseTree(javadocComment);
final DetailNode tree = convertParseTreeToDetailNode(parseTree);
// adjust first line to indent of /**
adjustFirstLineToJavadocIndent(tree,
javadocCommentAst.getColumnNo()
+ JAVADOC_START.length());
result.setTree(tree);
}
catch (ParseCancellationException | IllegalArgumentException ex) {
// If syntax error occurs then message is printed by error listener
// and parser throws this runtime exception to stop parsing.
// Just stop processing current Javadoc comment.
ParseErrorMessage parseErrorMessage = errorListener.getErrorMessage();
// There are cases when antlr error listener does not handle syntax error
if (parseErrorMessage == null) {
parseErrorMessage = new ParseErrorMessage(javadocCommentAst.getLineNo(),
MSG_KEY_UNRECOGNIZED_ANTLR_ERROR,
javadocCommentAst.getColumnNo(), ex.getMessage());
}
result.setParseErrorMessage(parseErrorMessage);
}
return result;
}
/**
* Parses block comment content as javadoc comment.
* @param blockComment
* block comment content.
* @return parse tree
*/
private ParseTree parseJavadocAsParseTree(String blockComment) {
final ANTLRInputStream input = new ANTLRInputStream(blockComment);
final JavadocLexer lexer = new JavadocLexer(input);
// remove default error listeners
lexer.removeErrorListeners();
// add custom error listener that logs parsing errors
lexer.addErrorListener(errorListener);
final CommonTokenStream tokens = new CommonTokenStream(lexer);
final JavadocParser parser = new JavadocParser(tokens);
// remove default error listeners
parser.removeErrorListeners();
// add custom error listener that logs syntax errors
parser.addErrorListener(errorListener);
// This strategy stops parsing when parser error occurs.
// By default it uses Error Recover Strategy which is slow and useless.
parser.setErrorHandler(new BailErrorStrategy());
return parser.javadoc();
}
/**
* Converts ParseTree (that is generated by ANTLRv4) to DetailNode tree.
*
* @param parseTreeNode root node of ParseTree
* @return root of DetailNode tree
*/
private DetailNode convertParseTreeToDetailNode(ParseTree parseTreeNode) {
final JavadocNodeImpl rootJavadocNode = createRootJavadocNode(parseTreeNode);
JavadocNodeImpl currentJavadocParent = rootJavadocNode;
ParseTree parseTreeParent = parseTreeNode;
while (currentJavadocParent != null) {
// remove unnecessary children tokens
if (currentJavadocParent.getType() == JavadocTokenTypes.TEXT) {
currentJavadocParent
.setChildren((DetailNode[]) JavadocNodeImpl.EMPTY_DETAIL_NODE_ARRAY);
}
final JavadocNodeImpl[] children =
(JavadocNodeImpl[]) currentJavadocParent.getChildren();
insertChildrenNodes(children, parseTreeParent);
if (children.length > 0) {
currentJavadocParent = children[0];
parseTreeParent = parseTreeParent.getChild(0);
}
else {
JavadocNodeImpl nextJavadocSibling = (JavadocNodeImpl) JavadocUtils
.getNextSibling(currentJavadocParent);
ParseTree nextParseTreeSibling = getNextSibling(parseTreeParent);
if (nextJavadocSibling == null) {
JavadocNodeImpl tempJavadocParent =
(JavadocNodeImpl) currentJavadocParent.getParent();
ParseTree tempParseTreeParent = parseTreeParent.getParent();
while (nextJavadocSibling == null && tempJavadocParent != null) {
nextJavadocSibling = (JavadocNodeImpl) JavadocUtils
.getNextSibling(tempJavadocParent);
nextParseTreeSibling = getNextSibling(tempParseTreeParent);
tempJavadocParent = (JavadocNodeImpl) tempJavadocParent.getParent();
tempParseTreeParent = tempParseTreeParent.getParent();
}
}
currentJavadocParent = nextJavadocSibling;
parseTreeParent = nextParseTreeSibling;
}
}
return rootJavadocNode;
}
/**
* Creates child nodes for each node from 'nodes' array.
* @param parseTreeParent original ParseTree parent node
* @param nodes array of JavadocNodeImpl nodes
*/
private void insertChildrenNodes(final JavadocNodeImpl[] nodes, ParseTree parseTreeParent) {
for (int i = 0; i < nodes.length; i++) {
final JavadocNodeImpl currentJavadocNode = nodes[i];
final ParseTree currentParseTreeNodeChild = parseTreeParent.getChild(i);
final JavadocNodeImpl[] subChildren =
createChildrenNodes(currentJavadocNode, currentParseTreeNodeChild);
currentJavadocNode.setChildren((DetailNode[]) subChildren);
}
}
/**
* Creates children Javadoc nodes base on ParseTree node's children.
* @param parentJavadocNode node that will be parent for created children
* @param parseTreeNode original ParseTree node
* @return array of Javadoc nodes
*/
private JavadocNodeImpl[]
createChildrenNodes(JavadocNodeImpl parentJavadocNode, ParseTree parseTreeNode) {
final JavadocNodeImpl[] children =
new JavadocNodeImpl[parseTreeNode.getChildCount()];
for (int j = 0; j < children.length; j++) {
final JavadocNodeImpl child =
createJavadocNode(parseTreeNode.getChild(j), parentJavadocNode, j);
children[j] = child;
}
return children;
}
/**
* Creates root JavadocNodeImpl node base on ParseTree root node.
* @param parseTreeNode ParseTree root node
* @return root Javadoc node
*/
private JavadocNodeImpl createRootJavadocNode(ParseTree parseTreeNode) {
final JavadocNodeImpl rootJavadocNode = createJavadocNode(parseTreeNode, null, -1);
final int childCount = parseTreeNode.getChildCount();
final JavadocNodeImpl[] children = new JavadocNodeImpl[childCount];
for (int i = 0; i < childCount; i++) {
final JavadocNodeImpl child = createJavadocNode(parseTreeNode.getChild(i),
rootJavadocNode, i);
children[i] = child;
}
rootJavadocNode.setChildren((DetailNode[]) children);
return rootJavadocNode;
}
/**
* Creates JavadocNodeImpl node on base of ParseTree node.
*
* @param parseTree ParseTree node
* @param parent DetailNode that will be parent of new node
* @param index child index that has new node
* @return JavadocNodeImpl node on base of ParseTree node.
*/
private JavadocNodeImpl createJavadocNode(ParseTree parseTree, DetailNode parent, int index) {
final JavadocNodeImpl node = new JavadocNodeImpl();
node.setText(parseTree.getText());
node.setColumnNumber(getColumn(parseTree));
node.setLineNumber(getLine(parseTree) + blockCommentLineNumber);
node.setIndex(index);
node.setType(getTokenType(parseTree));
node.setParent(parent);
node.setChildren((DetailNode[]) new JavadocNodeImpl[parseTree.getChildCount()]);
return node;
}
/**
* Adjust first line nodes to javadoc indent.
* @param tree DetailNode tree root
* @param javadocColumnNumber javadoc indent
*/
private void adjustFirstLineToJavadocIndent(DetailNode tree, int javadocColumnNumber) {
if (tree.getLineNumber() == blockCommentLineNumber) {
((JavadocNodeImpl) tree).setColumnNumber(tree.getColumnNumber() + javadocColumnNumber);
final DetailNode[] children = tree.getChildren();
for (DetailNode child : children) {
adjustFirstLineToJavadocIndent(child, javadocColumnNumber);
}
}
}
/**
* Gets line number from ParseTree node.
* @param tree
* ParseTree node
* @return line number
*/
private static int getLine(ParseTree tree) {
final int line;
if (tree instanceof TerminalNode) {
line = ((TerminalNode) tree).getSymbol().getLine() - 1;
}
else {
final ParserRuleContext rule = (ParserRuleContext) tree;
line = rule.start.getLine() - 1;
}
return line;
}
/**
* Gets column number from ParseTree node.
* @param tree
* ParseTree node
* @return column number
*/
private static int getColumn(ParseTree tree) {
final int column;
if (tree instanceof TerminalNode) {
column = ((TerminalNode) tree).getSymbol().getCharPositionInLine();
}
else {
final ParserRuleContext rule = (ParserRuleContext) tree;
column = rule.start.getCharPositionInLine();
}
return column;
}
/**
* Gets next sibling of ParseTree node.
* @param node ParseTree node
* @return next sibling of ParseTree node.
*/
private static ParseTree getNextSibling(ParseTree node) {
ParseTree nextSibling = null;
if (node.getParent() != null) {
final ParseTree parent = node.getParent();
final int childCount = parent.getChildCount();
int index = 0;
while (true) {
final ParseTree currentNode = parent.getChild(index);
if (currentNode.equals(node)) {
if (index != childCount - 1) {
nextSibling = parent.getChild(index + 1);
}
break;
}
index++;
}
}
return nextSibling;
}
/**
* Gets token type of ParseTree node from JavadocTokenTypes class.
* @param node ParseTree node.
* @return token type from JavadocTokenTypes
*/
private static int getTokenType(ParseTree node) {
final int tokenType;
if (node.getChildCount() == 0) {
tokenType = ((TerminalNode) node).getSymbol().getType();
}
else {
final String className = getNodeClassNameWithoutContext(node);
final String typeName =
CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, className);
tokenType = JavadocUtils.getTokenId(typeName);
}
return tokenType;
}
/**
* Gets class name of ParseTree node and removes 'Context' postfix at the
* end.
* @param node
* ParseTree node.
* @return class name without 'Context'
*/
private static String getNodeClassNameWithoutContext(ParseTree node) {
final String className = node.getClass().getSimpleName();
// remove 'Context' at the end
final int contextLength = 7;
return className.substring(0, className.length() - contextLength);
}
/**
* Custom error listener for JavadocParser that prints user readable errors.
*/
private static class DescriptiveErrorListener extends BaseErrorListener {
/**
* Offset is line number of beginning of the Javadoc comment. Log
* messages should have line number in scope of file, not in scope of
* Javadoc comment.
*/
private int offset;
/**
* Error message that appeared while parsing.
*/
private ParseErrorMessage errorMessage;
/**
* Getter for error message during parsing.
* @return Error message during parsing.
*/
private ParseErrorMessage getErrorMessage() {
return errorMessage;
}
/**
* Sets offset. Offset is line number of beginning of the Javadoc
* comment. Log messages should have line number in scope of file, not
* in scope of Javadoc comment.
* @param offset
* offset line number
*/
public void setOffset(int offset) {
this.offset = offset;
}
/**
* Logs parser errors in Checkstyle manner. Parser can generate error
* messages. There is special error that parser can generate. It is
* missed close HTML tag. This case is special because parser prints
* error like {@code "no viable alternative at input 'b \n *\n'"} and it
* is not clear that error is about missed close HTML tag. Other error
* messages are not special and logged simply as "Parse Error...".
*
* <p>{@inheritDoc}
*/
@Override
public void syntaxError(
Recognizer<?, ?> recognizer, Object offendingSymbol,
int line, int charPositionInLine,
String msg, RecognitionException ex) {
final int lineNumber = offset + line;
final Token token = (Token) offendingSymbol;
if (MSG_JAVADOC_MISSED_HTML_CLOSE.equals(msg)) {
errorMessage = new ParseErrorMessage(lineNumber,
MSG_JAVADOC_MISSED_HTML_CLOSE, charPositionInLine, token.getText());
throw new IllegalArgumentException(msg);
}
else if (MSG_JAVADOC_WRONG_SINGLETON_TAG.equals(msg)) {
errorMessage = new ParseErrorMessage(lineNumber,
MSG_JAVADOC_WRONG_SINGLETON_TAG, charPositionInLine, token.getText());
throw new IllegalArgumentException(msg);
}
else {
final int ruleIndex = ex.getCtx().getRuleIndex();
final String ruleName = recognizer.getRuleNames()[ruleIndex];
final String upperCaseRuleName = CaseFormat.UPPER_CAMEL.to(
CaseFormat.UPPER_UNDERSCORE, ruleName);
errorMessage = new ParseErrorMessage(lineNumber,
MSG_JAVADOC_PARSE_RULE_ERROR, charPositionInLine, msg, upperCaseRuleName);
}
}
}
/**
* Contains result of parsing javadoc comment: DetailNode tree and parse
* error message.
*/
public static class ParseStatus {
/**
* DetailNode tree (is null if parsing fails).
*/
private DetailNode tree;
/**
* Parse error message (is null if parsing is successful).
*/
private ParseErrorMessage parseErrorMessage;
/**
* Getter for DetailNode tree.
* @return DetailNode tree if parsing was successful, null otherwise.
*/
public DetailNode getTree() {
return tree;
}
/**
* Sets DetailNode tree.
* @param tree DetailNode tree.
*/
public void setTree(DetailNode tree) {
this.tree = tree;
}
/**
* Getter for error message during parsing.
* @return Error message if parsing was unsuccessful, null otherwise.
*/
public ParseErrorMessage getParseErrorMessage() {
return parseErrorMessage;
}
/**
* Sets parse error message.
* @param parseErrorMessage Parse error message.
*/
public void setParseErrorMessage(ParseErrorMessage parseErrorMessage) {
this.parseErrorMessage = parseErrorMessage;
}
}
/**
* Contains information about parse error message.
*/
public static class ParseErrorMessage {
/**
* Line number where parse error occurred.
*/
private final int lineNumber;
/**
* Key for error message.
*/
private final String messageKey;
/**
* Error message arguments.
*/
private final Object[] messageArguments;
/**
* Initializes parse error message.
*
* @param lineNumber line number
* @param messageKey message key
* @param messageArguments message arguments
*/
ParseErrorMessage(int lineNumber, String messageKey, Object... messageArguments) {
this.lineNumber = lineNumber;
this.messageKey = messageKey;
this.messageArguments = messageArguments.clone();
}
/**
* Getter for line number where parse error occurred.
* @return Line number where parse error occurred.
*/
public int getLineNumber() {
return lineNumber;
}
/**
* Getter for key for error message.
* @return Key for error message.
*/
public String getMessageKey() {
return messageKey;
}
/**
* Getter for error message arguments.
* @return Array of error message arguments.
*/
public Object[] getMessageArguments() {
return messageArguments.clone();
}
}
}