////////////////////////////////////////////////////////////////////////////////
// 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.checks;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.AuditEvent;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
/**
* Maintains a set of check suppressions from {@link SuppressWarnings}
* annotations.
* @author Trevor Robinson
* @author Stéphane Galland
*/
public class SuppressWarningsHolder
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "suppress.warnings.invalid.target";
/**
* Optional prefix for warning suppressions that are only intended to be
* recognized by checkstyle. For instance, to suppress {@code
* FallThroughCheck} only in checkstyle (and not in javac), use the
* suppression {@code "checkstyle:fallthrough"} or {@code "checkstyle:FallThrough"}.
* To suppress the warning in both tools, just use {@code "fallthrough"}.
*/
public static final String CHECKSTYLE_PREFIX = "checkstyle:";
/** Java.lang namespace prefix, which is stripped from SuppressWarnings */
private static final String JAVA_LANG_PREFIX = "java.lang.";
/** Suffix to be removed from subclasses of Check. */
private static final String CHECK_SUFFIX = "Check";
/** Special warning id for matching all the warnings. */
private static final String ALL_WARNING_MATCHING_ID = "all";
/** A map from check source names to suppression aliases. */
private static final Map<String, String> CHECK_ALIAS_MAP = new HashMap<>();
/**
* A thread-local holder for the list of suppression entries for the last
* file parsed.
*/
private static final ThreadLocal<List<Entry>> ENTRIES = new ThreadLocal<List<Entry>>() {
@Override
protected List<Entry> initialValue() {
return new LinkedList<>();
}
};
/**
* Returns the default alias for the source name of a check, which is the
* source name in lower case with any dotted prefix or "Check" suffix
* removed.
* @param sourceName the source name of the check (generally the class
* name)
* @return the default alias for the given check
*/
public static String getDefaultAlias(String sourceName) {
int endIndex = sourceName.length();
if (sourceName.endsWith(CHECK_SUFFIX)) {
endIndex -= CHECK_SUFFIX.length();
}
final int startIndex = sourceName.lastIndexOf('.') + 1;
return sourceName.substring(startIndex, endIndex).toLowerCase(Locale.ENGLISH);
}
/**
* Returns the alias for the source name of a check. If an alias has been
* explicitly registered via {@link #registerAlias(String, String)}, that
* alias is returned; otherwise, the default alias is used.
* @param sourceName the source name of the check (generally the class
* name)
* @return the current alias for the given check
*/
public static String getAlias(String sourceName) {
String checkAlias = CHECK_ALIAS_MAP.get(sourceName);
if (checkAlias == null) {
checkAlias = getDefaultAlias(sourceName);
}
return checkAlias;
}
/**
* Registers an alias for the source name of a check.
* @param sourceName the source name of the check (generally the class
* name)
* @param checkAlias the alias used in {@link SuppressWarnings} annotations
*/
public static void registerAlias(String sourceName, String checkAlias) {
CHECK_ALIAS_MAP.put(sourceName, checkAlias);
}
/**
* Registers a list of source name aliases based on a comma-separated list
* of {@code source=alias} items, such as {@code
* com.puppycrawl.tools.checkstyle.checks.sizes.ParameterNumberCheck=
* paramnum}.
* @param aliasList the list of comma-separated alias assignments
*/
public void setAliasList(String... aliasList) {
for (String sourceAlias : aliasList) {
final int index = sourceAlias.indexOf('=');
if (index > 0) {
registerAlias(sourceAlias.substring(0, index), sourceAlias
.substring(index + 1));
}
else if (!sourceAlias.isEmpty()) {
throw new IllegalArgumentException(
"'=' expected in alias list item: " + sourceAlias);
}
}
}
/**
* Checks for a suppression of a check with the given source name and
* location in the last file processed.
* @param event audit event.
* @return whether the check with the given name is suppressed at the given
* source location
*/
public static boolean isSuppressed(AuditEvent event) {
final List<Entry> entries = ENTRIES.get();
final String sourceName = event.getSourceName();
final String checkAlias = getAlias(sourceName);
final int line = event.getLine();
final int column = event.getColumn();
boolean suppressed = false;
for (Entry entry : entries) {
final boolean afterStart = isSuppressedAfterEventStart(line, column, entry);
final boolean beforeEnd = isSuppressedBeforeEventEnd(line, column, entry);
final boolean nameMatches =
ALL_WARNING_MATCHING_ID.equals(entry.getCheckName())
|| entry.getCheckName().equalsIgnoreCase(checkAlias);
final boolean idMatches = event.getModuleId() != null
&& event.getModuleId().equals(entry.getCheckName());
if (afterStart && beforeEnd && (nameMatches || idMatches)) {
suppressed = true;
break;
}
}
return suppressed;
}
/**
* Checks whether suppression entry position is after the audit event occurrence position
* in the source file.
* @param line the line number in the source file where the event occurred.
* @param column the column number in the source file where the event occurred.
* @param entry suppression entry.
* @return true if suppression entry position is after the audit event occurrence position
* in the source file.
*/
private static boolean isSuppressedAfterEventStart(int line, int column, Entry entry) {
return entry.getFirstLine() < line
|| entry.getFirstLine() == line
&& (column == 0 || entry.getFirstColumn() <= column);
}
/**
* Checks whether suppression entry position is before the audit event occurrence position
* in the source file.
* @param line the line number in the source file where the event occurred.
* @param column the column number in the source file where the event occurred.
* @param entry suppression entry.
* @return true if suppression entry position is before the audit event occurrence position
* in the source file.
*/
private static boolean isSuppressedBeforeEventEnd(int line, int column, Entry entry) {
return entry.getLastLine() > line
|| entry.getLastLine() == line && entry
.getLastColumn() >= column;
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {TokenTypes.ANNOTATION};
}
@Override
public int[] getRequiredTokens() {
return getAcceptableTokens();
}
@Override
public void beginTree(DetailAST rootAST) {
ENTRIES.get().clear();
}
@Override
public void visitToken(DetailAST ast) {
// check whether annotation is SuppressWarnings
// expected children: AT ( IDENT | DOT ) LPAREN <values> RPAREN
String identifier = getIdentifier(getNthChild(ast, 1));
if (identifier.startsWith(JAVA_LANG_PREFIX)) {
identifier = identifier.substring(JAVA_LANG_PREFIX.length());
}
if ("SuppressWarnings".equals(identifier)) {
final List<String> values = getAllAnnotationValues(ast);
if (!isAnnotationEmpty(values)) {
final DetailAST targetAST = getAnnotationTarget(ast);
if (targetAST == null) {
log(ast.getLineNo(), MSG_KEY);
}
else {
// get text range of target
final int firstLine = targetAST.getLineNo();
final int firstColumn = targetAST.getColumnNo();
final DetailAST nextAST = targetAST.getNextSibling();
final int lastLine;
final int lastColumn;
if (nextAST == null) {
lastLine = Integer.MAX_VALUE;
lastColumn = Integer.MAX_VALUE;
}
else {
lastLine = nextAST.getLineNo();
lastColumn = nextAST.getColumnNo() - 1;
}
// add suppression entries for listed checks
final List<Entry> entries = ENTRIES.get();
for (String value : values) {
String checkName = value;
// strip off the checkstyle-only prefix if present
checkName = removeCheckstylePrefixIfExists(checkName);
entries.add(new Entry(checkName, firstLine, firstColumn,
lastLine, lastColumn));
}
}
}
}
}
/**
* Method removes checkstyle prefix (checkstyle:) from check name if exists.
*
* @param checkName
* - name of the check
* @return check name without prefix
*/
private static String removeCheckstylePrefixIfExists(String checkName) {
String result = checkName;
if (checkName.startsWith(CHECKSTYLE_PREFIX)) {
result = checkName.substring(CHECKSTYLE_PREFIX.length());
}
return result;
}
/**
* Get all annotation values.
* @param ast annotation token
* @return list values
*/
private static List<String> getAllAnnotationValues(DetailAST ast) {
// get values of annotation
List<String> values = null;
final DetailAST lparenAST = ast.findFirstToken(TokenTypes.LPAREN);
if (lparenAST != null) {
final DetailAST nextAST = lparenAST.getNextSibling();
final int nextType = nextAST.getType();
switch (nextType) {
case TokenTypes.EXPR:
case TokenTypes.ANNOTATION_ARRAY_INIT:
values = getAnnotationValues(nextAST);
break;
case TokenTypes.ANNOTATION_MEMBER_VALUE_PAIR:
// expected children: IDENT ASSIGN ( EXPR |
// ANNOTATION_ARRAY_INIT )
values = getAnnotationValues(getNthChild(nextAST, 2));
break;
case TokenTypes.RPAREN:
// no value present (not valid Java)
break;
default:
// unknown annotation value type (new syntax?)
throw new IllegalArgumentException("Unexpected AST: " + nextAST);
}
}
return values;
}
/**
* Checks that annotation is empty.
* @param values list of values in the annotation
* @return whether annotation is empty or contains some values
*/
private static boolean isAnnotationEmpty(List<String> values) {
return values == null;
}
/**
* Get target of annotation.
* @param ast the AST node to get the child of
* @return get target of annotation
*/
private static DetailAST getAnnotationTarget(DetailAST ast) {
final DetailAST targetAST;
final DetailAST parentAST = ast.getParent();
switch (parentAST.getType()) {
case TokenTypes.MODIFIERS:
case TokenTypes.ANNOTATIONS:
targetAST = getAcceptableParent(parentAST);
break;
default:
// unexpected container type
throw new IllegalArgumentException("Unexpected container AST: " + parentAST);
}
return targetAST;
}
/**
* Returns parent of given ast if parent has one of the following types:
* ANNOTATION_DEF, PACKAGE_DEF, CLASS_DEF, ENUM_DEF, ENUM_CONSTANT_DEF, CTOR_DEF,
* METHOD_DEF, PARAMETER_DEF, VARIABLE_DEF, ANNOTATION_FIELD_DEF, TYPE, LITERAL_NEW,
* LITERAL_THROWS, TYPE_ARGUMENT, IMPLEMENTS_CLAUSE, DOT.
* @param child an ast
* @return returns ast - parent of given
*/
private static DetailAST getAcceptableParent(DetailAST child) {
final DetailAST result;
final DetailAST parent = child.getParent();
switch (parent.getType()) {
case TokenTypes.ANNOTATION_DEF:
case TokenTypes.PACKAGE_DEF:
case TokenTypes.CLASS_DEF:
case TokenTypes.INTERFACE_DEF:
case TokenTypes.ENUM_DEF:
case TokenTypes.ENUM_CONSTANT_DEF:
case TokenTypes.CTOR_DEF:
case TokenTypes.METHOD_DEF:
case TokenTypes.PARAMETER_DEF:
case TokenTypes.VARIABLE_DEF:
case TokenTypes.ANNOTATION_FIELD_DEF:
case TokenTypes.TYPE:
case TokenTypes.LITERAL_NEW:
case TokenTypes.LITERAL_THROWS:
case TokenTypes.TYPE_ARGUMENT:
case TokenTypes.IMPLEMENTS_CLAUSE:
case TokenTypes.DOT:
result = parent;
break;
default:
// it's possible case, but shouldn't be processed here
result = null;
}
return result;
}
/**
* Returns the n'th child of an AST node.
* @param ast the AST node to get the child of
* @param index the index of the child to get
* @return the n'th child of the given AST node, or {@code null} if none
*/
private static DetailAST getNthChild(DetailAST ast, int index) {
DetailAST child = ast.getFirstChild();
for (int i = 0; i < index && child != null; ++i) {
child = child.getNextSibling();
}
return child;
}
/**
* Returns the Java identifier represented by an AST.
* @param ast an AST node for an IDENT or DOT
* @return the Java identifier represented by the given AST subtree
* @throws IllegalArgumentException if the AST is invalid
*/
private static String getIdentifier(DetailAST ast) {
if (ast == null) {
throw new IllegalArgumentException("Identifier AST expected, but get null.");
}
final String identifier;
if (ast.getType() == TokenTypes.IDENT) {
identifier = ast.getText();
}
else {
identifier = getIdentifier(ast.getFirstChild()) + "."
+ getIdentifier(ast.getLastChild());
}
return identifier;
}
/**
* Returns the literal string expression represented by an AST.
* @param ast an AST node for an EXPR
* @return the Java string represented by the given AST expression
* or empty string if expression is too complex
* @throws IllegalArgumentException if the AST is invalid
*/
private static String getStringExpr(DetailAST ast) {
final DetailAST firstChild = ast.getFirstChild();
String expr = "";
switch (firstChild.getType()) {
case TokenTypes.STRING_LITERAL:
// NOTE: escaped characters are not unescaped
final String quotedText = firstChild.getText();
expr = quotedText.substring(1, quotedText.length() - 1);
break;
case TokenTypes.IDENT:
expr = firstChild.getText();
break;
case TokenTypes.DOT:
expr = firstChild.getLastChild().getText();
break;
default:
// annotations with complex expressions cannot suppress warnings
}
return expr;
}
/**
* Returns the annotation values represented by an AST.
* @param ast an AST node for an EXPR or ANNOTATION_ARRAY_INIT
* @return the list of Java string represented by the given AST for an
* expression or annotation array initializer
* @throws IllegalArgumentException if the AST is invalid
*/
private static List<String> getAnnotationValues(DetailAST ast) {
final List<String> annotationValues;
switch (ast.getType()) {
case TokenTypes.EXPR:
annotationValues = Collections.singletonList(getStringExpr(ast));
break;
case TokenTypes.ANNOTATION_ARRAY_INIT:
annotationValues = findAllExpressionsInChildren(ast);
break;
default:
throw new IllegalArgumentException(
"Expression or annotation array initializer AST expected: " + ast);
}
return annotationValues;
}
/**
* Method looks at children and returns list of expressions in strings.
* @param parent ast, that contains children
* @return list of expressions in strings
*/
private static List<String> findAllExpressionsInChildren(DetailAST parent) {
final List<String> valueList = new LinkedList<>();
DetailAST childAST = parent.getFirstChild();
while (childAST != null) {
if (childAST.getType() == TokenTypes.EXPR) {
valueList.add(getStringExpr(childAST));
}
childAST = childAST.getNextSibling();
}
return valueList;
}
/** Records a particular suppression for a region of a file. */
private static class Entry {
/** The source name of the suppressed check. */
private final String checkName;
/** The suppression region for the check - first line. */
private final int firstLine;
/** The suppression region for the check - first column. */
private final int firstColumn;
/** The suppression region for the check - last line. */
private final int lastLine;
/** The suppression region for the check - last column. */
private final int lastColumn;
/**
* Constructs a new suppression region entry.
* @param checkName the source name of the suppressed check
* @param firstLine the first line of the suppression region
* @param firstColumn the first column of the suppression region
* @param lastLine the last line of the suppression region
* @param lastColumn the last column of the suppression region
*/
Entry(String checkName, int firstLine, int firstColumn,
int lastLine, int lastColumn) {
this.checkName = checkName;
this.firstLine = firstLine;
this.firstColumn = firstColumn;
this.lastLine = lastLine;
this.lastColumn = lastColumn;
}
/**
* Gets he source name of the suppressed check.
* @return the source name of the suppressed check
*/
public String getCheckName() {
return checkName;
}
/**
* Gets the first line of the suppression region.
* @return the first line of the suppression region
*/
public int getFirstLine() {
return firstLine;
}
/**
* Gets the first column of the suppression region.
* @return the first column of the suppression region
*/
public int getFirstColumn() {
return firstColumn;
}
/**
* Gets the last line of the suppression region.
* @return the last line of the suppression region
*/
public int getLastLine() {
return lastLine;
}
/**
* Gets the last column of the suppression region.
* @return the last column of the suppression region
*/
public int getLastColumn() {
return lastColumn;
}
}
}