com.google.errorprone.bugpatterns.MathRoundIntLong Maven / Gradle / Ivy
/*
* Copyright 2018 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.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Matchers.allOf;
import static com.google.errorprone.matchers.Matchers.anyOf;
import static com.google.errorprone.matchers.Matchers.argument;
import static com.google.errorprone.matchers.Matchers.isSameType;
import static com.google.errorprone.matchers.Matchers.staticMethod;
import com.google.common.collect.Iterables;
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.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
/**
* Check for calls to Math's {@link Math#round} with an integer or long parameter.
*
* @author [email protected] (Sabrina Seibel)
*/
@BugPattern(
name = "MathRoundIntLong",
summary = "Math.round(Integer) results in truncation",
explanation =
"Math.round() called with an integer or long type results in truncation"
+ " because Math.round only accepts floats or doubles and some integers and longs can't"
+ " be represented with float.",
severity = ERROR)
public final class MathRoundIntLong extends BugChecker implements MethodInvocationTreeMatcher {
private static final Matcher MATH_ROUND_CALLS =
staticMethod().onClass("java.lang.Math").named("round");
private static final Matcher ROUND_CALLS_WITH_INT_ARG =
allOf(
MATH_ROUND_CALLS, argument(0, anyOf(isSameType("int"), isSameType("java.lang.Integer"))));
private static final Matcher ROUND_CALLS_WITH_LONG_ARG =
allOf(MATH_ROUND_CALLS, argument(0, anyOf(isSameType("long"), isSameType("java.lang.Long"))));
private static final Matcher ROUND_CALLS_WITH_INT_OR_LONG_ARG =
anyOf(ROUND_CALLS_WITH_INT_ARG, ROUND_CALLS_WITH_LONG_ARG);
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
return ROUND_CALLS_WITH_INT_OR_LONG_ARG.matches(tree, state)
? removeMathRoundCall(tree, state)
: Description.NO_MATCH;
}
private Description removeMathRoundCall(MethodInvocationTree tree, VisitorState state) {
if (ROUND_CALLS_WITH_INT_ARG.matches(tree, state)) {
if (ASTHelpers.requiresParentheses(Iterables.getOnlyElement(tree.getArguments()), state)) {
return describeMatch(
tree,
SuggestedFix.builder()
.prefixWith(tree, "(")
.replace(tree, state.getSourceForNode(tree.getArguments().get(0)))
.postfixWith(tree, ")")
.build());
}
return describeMatch(
tree, SuggestedFix.replace(tree, state.getSourceForNode(tree.getArguments().get(0))));
} else if (ROUND_CALLS_WITH_LONG_ARG.matches(tree, state)) {
// TODO(b/112270644): skip Ints.saturatedCast fix if guava isn't on the classpath
return describeMatch(
tree,
SuggestedFix.builder()
.addImport("com.google.common.primitives.Ints")
.prefixWith(tree, "Ints.saturatedCast(")
.replace(tree, state.getSourceForNode(tree.getArguments().get(0)))
.postfixWith(tree, ")")
.build());
}
throw new AssertionError(
"Unknown argument type to round call: " + state.getSourceForNode(tree));
}
}