com.google.errorprone.bugpatterns.InexactVarargsConditional Maven / Gradle / Ivy
/*
* Copyright 2017 The Error Prone Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.errorprone.bugpatterns;
import static com.google.common.collect.Iterables.getLast;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.getType;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.fixes.SuggestedFixes;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ConditionalExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Types;
/** A {@link BugChecker}; see the associated {@link BugPattern} annotation for details. */
@BugPattern(
summary = "Conditional expression in varargs call contains array and non-array arguments",
severity = ERROR)
public class InexactVarargsConditional extends BugChecker implements MethodInvocationTreeMatcher {
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
MethodSymbol sym = ASTHelpers.getSymbol(tree);
if (!sym.isVarArgs()) {
return NO_MATCH;
}
if (tree.getArguments().size() != sym.getParameters().size()) {
// explicit varargs call with more actuals than formals
return NO_MATCH;
}
Tree arg = getLast(tree.getArguments());
if (!(arg instanceof ConditionalExpressionTree)) {
return NO_MATCH;
}
Types types = state.getTypes();
if (types.isArray(getType(arg))) {
return NO_MATCH;
}
ConditionalExpressionTree cond = (ConditionalExpressionTree) arg;
boolean trueIsArray = types.isArray(getType(cond.getTrueExpression()));
if (!(trueIsArray ^ types.isArray(getType(cond.getFalseExpression())))) {
return NO_MATCH;
}
SuggestedFix.Builder fix = SuggestedFix.builder();
String qualified =
SuggestedFixes.qualifyType(
state, fix, types.elemtype(getLast(sym.getParameters()).asType()));
Tree toFix = !trueIsArray ? cond.getTrueExpression() : cond.getFalseExpression();
fix.prefixWith(toFix, String.format("new %s[] {", qualified)).postfixWith(toFix, "}");
return describeMatch(tree, fix.build());
}
}