/*
* SonarQube Java
* Copyright (C) 2012-2016 SonarSource SA
* mailto:contact AT sonarsource DOT com
*
* This program 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 3 of the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.sonar.java.checks;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Multimap;
import org.sonar.check.Rule;
import org.sonar.java.matcher.MethodMatcher;
import org.sonar.java.matcher.MethodMatcherCollection;
import org.sonar.java.matcher.NameCriteria;
import org.sonar.java.matcher.TypeCriteria;
import org.sonar.java.model.ExpressionUtils;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.semantic.Type;
import org.sonar.plugins.java.api.tree.ArrayDimensionTree;
import org.sonar.plugins.java.api.tree.AssignmentExpressionTree;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.LiteralTree;
import org.sonar.plugins.java.api.tree.MemberSelectExpressionTree;
import org.sonar.plugins.java.api.tree.MethodInvocationTree;
import org.sonar.plugins.java.api.tree.NewArrayTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.VariableTree;
import javax.annotation.Nullable;
import java.text.MessageFormat;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
@Rule(key = "S2386")
public class PublicStaticMutableMembersCheck extends IssuableSubscriptionVisitor {
private static final Set<String> ALWAYS_MUTABLE_TYPES = ImmutableSet.of(
"java.awt.Point",
"java.util.Date"
);
private static final Set<String> MUTABLE_TYPES = ImmutableSet.<String>builder()
.addAll(ALWAYS_MUTABLE_TYPES)
.add("java.util.Collection")
.add("java.util.Map")
.build();
private static final String DECORATE = "decorate";
// java.util and apache commons
private static final MethodMatcherCollection UNMODIFIABLE_METHOD_CALLS = MethodMatcherCollection.create()
.add(MethodMatcher.create().typeDefinition(TypeCriteria.anyType()).name(NameCriteria.startsWith("unmodifiable")).withAnyParameters())
// apache commons 3.X
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections.map.UnmodifiableMap")).name(DECORATE).withAnyParameters())
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections.set.UnmodifiableSet")).name(DECORATE).withAnyParameters())
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections.list.UnmodifiableList")).name(DECORATE).withAnyParameters())
// apache commons 4.X
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections4.map.UnmodifiableMap")).name(DECORATE).withAnyParameters())
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections4.set.UnmodifiableSet")).name(DECORATE).withAnyParameters())
.add(MethodMatcher.create().typeDefinition(TypeCriteria.subtypeOf("org.apache.commons.collections4.list.UnmodifiableList")).name(DECORATE).withAnyParameters());
private static final MethodMatcher ARRAYS_AS_LIST = MethodMatcher.create()
.typeDefinition("java.util.Arrays").name("asList").withAnyParameters();
private static final Set<String> ACCEPTED_TYPES = ImmutableSet.of(
"com.google.common.collect.ImmutableMap",
"com.google.common.collect.ImmutableCollection"
);
private static final Set<String> ACCEPTED_NEW_TYPES = ImmutableSet.of(
"org.apache.commons.collections4.list.UnmodifiableList"
);
private static final Set<Symbol> IMMUTABLE_CANDIDATES = new HashSet<>();
private static final Multimap<Tree, Symbol> CLASS_IMMUTABLE_CANDIDATES = ArrayListMultimap.create();
@Override
public List<Tree.Kind> nodesToVisit() {
return ImmutableList.of(Tree.Kind.INTERFACE, Tree.Kind.CLASS, Tree.Kind.ENUM, Tree.Kind.ASSIGNMENT);
}
@Override
public void scanFile(JavaFileScannerContext context) {
super.scanFile(context);
CLASS_IMMUTABLE_CANDIDATES.clear();
}
@Override
public void visitNode(Tree tree) {
if (tree.is(Tree.Kind.ASSIGNMENT)) {
checkAssignment((AssignmentExpressionTree) tree);
} else {
List<Tree> members = ((ClassTree) tree).members();
for (Tree member : members) {
if (member.is(Tree.Kind.VARIABLE)) {
preCheckVariable(tree, (VariableTree) member);
}
}
}
}
private void preCheckVariable(Tree owner, VariableTree variableTree) {
Symbol symbol = variableTree.symbol();
if (symbol != null && isPublicStatic(symbol) && isForbiddenType(symbol.type())) {
if (isMutable(variableTree.initializer(), symbol)) {
String message = "Make this member \"protected\".";
if (owner.is(Tree.Kind.INTERFACE)) {
message = MessageFormat.format("Move \"{0}\" to a class and lower its visibility", variableTree.simpleName().name());
}
reportIssue(variableTree.simpleName(), message);
} else {
IMMUTABLE_CANDIDATES.add(symbol);
CLASS_IMMUTABLE_CANDIDATES.put(owner, symbol);
}
}
}
private void checkAssignment(AssignmentExpressionTree node) {
ExpressionTree variable = ExpressionUtils.skipParentheses(node.variable());
if (variable.is(Tree.Kind.MEMBER_SELECT)) {
variable = ((MemberSelectExpressionTree) variable).identifier();
}
if (variable.is(Tree.Kind.IDENTIFIER)) {
IdentifierTree identifierTree = (IdentifierTree) variable;
Symbol symbol = identifierTree.symbol();
if (IMMUTABLE_CANDIDATES.contains(symbol) && isMutable(node.expression(), symbol)) {
reportIssue(identifierTree, "Make member \"" + symbol.name() + "\" \"protected\".");
IMMUTABLE_CANDIDATES.remove(symbol);
}
}
}
@Override
public void leaveNode(Tree tree) {
// cleanup
if (tree.is(Tree.Kind.CLASS, Tree.Kind.ENUM)) {
IMMUTABLE_CANDIDATES.removeAll(CLASS_IMMUTABLE_CANDIDATES.get(tree));
}
}
static boolean isMutable(@Nullable ExpressionTree initializer, Symbol symbol) {
Type type = symbol.type();
if (initializer == null) {
return ALWAYS_MUTABLE_TYPES.stream().anyMatch(type::isSubtypeOf);
}
if (symbol.isFinal() && isEmptyArray(initializer)) {
return false;
}
ExpressionTree expression = ExpressionUtils.skipParentheses(initializer);
if (expression.is(Tree.Kind.METHOD_INVOCATION)) {
return returnValueIsMutable((MethodInvocationTree) expression);
} else if (expression.is(Tree.Kind.NEW_CLASS)) {
return !isAcceptedType(expression.symbolType(), ACCEPTED_NEW_TYPES);
}
return true;
}
private static boolean isEmptyArray(ExpressionTree expression) {
if (!expression.is(Tree.Kind.NEW_ARRAY)) {
return false;
}
NewArrayTree nat = (NewArrayTree) expression;
return hasEmptyInitializer(nat) || hasOnlyZeroDimensions(nat.dimensions());
}
private static boolean hasEmptyInitializer(NewArrayTree newArrayTree) {
return newArrayTree.openBraceToken() != null && newArrayTree.initializers().isEmpty();
}
private static boolean hasOnlyZeroDimensions(List<ArrayDimensionTree> dimensions) {
return !dimensions.isEmpty() && dimensions.stream().allMatch(PublicStaticMutableMembersCheck::isZeroDimension);
}
private static boolean isZeroDimension(ArrayDimensionTree dim) {
ExpressionTree expression = dim.expression();
return expression != null && expression.is(Tree.Kind.INT_LITERAL) && "0".equals(((LiteralTree) expression).value());
}
private static boolean returnValueIsMutable(MethodInvocationTree mit) {
if (isAcceptedTypeOrUnmodifiableMethodCall(mit)) {
return false;
} else if (ARRAYS_AS_LIST.matches(mit)) {
return !mit.arguments().isEmpty();
}
return true;
}
private static boolean isAcceptedTypeOrUnmodifiableMethodCall(MethodInvocationTree mit) {
Type type = mit.symbolType();
return type.isUnknown() || isAcceptedType(type, ACCEPTED_TYPES) || UNMODIFIABLE_METHOD_CALLS.anyMatch(mit);
}
private static boolean isAcceptedType(Type type, Set<String> accepted) {
for (String acceptedType : accepted) {
if (type.isSubtypeOf(acceptedType)) {
return true;
}
}
return false;
}
static boolean isPublicStatic(Symbol symbol) {
return symbol.isStatic() && symbol.isPublic();
}
static boolean isForbiddenType(final Type type) {
return type.isArray() || MUTABLE_TYPES.stream().anyMatch(type::isSubtypeOf);
}
}