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Simplify ArrayHashCode fix handling. #5272

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Merged
copybara-service merged 1 commit into from
Oct 15, 2025
Merged

Simplify ArrayHashCode fix handling. #5272

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28 changes: 11 additions & 17 deletions core/src/main/java/com/google/errorprone/bugpatterns/ArrayHashCode.java
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
import static com.google.errorprone.matchers.Matchers.instanceMethod;
import static com.google.errorprone.matchers.Matchers.staticMethod;
import static com.google.errorprone.predicates.TypePredicates.isArray;
import static com.google.errorprone.util.ASTHelpers.getType;

import com.google.common.base.Preconditions;
import com.google.errorprone.BugPattern;
Expand All @@ -33,7 +34,6 @@
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.Matchers;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.tools.javac.code.Type;
Expand Down Expand Up @@ -81,22 +81,17 @@ public class ArrayHashCode extends BugChecker implements MethodInvocationTreeMat
*/
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
SuggestedFix.Builder fix = null;
var fix = SuggestedFix.builder();
Types types = state.getTypes();
if (jdk7HashCodeMethodMatcher.matches(tree, state)) {
// java.util.Objects#hashCode takes a single argument, so rewrite the whole method call
// to use Arrays.hashCode/deepHashCode instead.
fix =
SuggestedFix.builder()
.replace(tree, rewriteArrayArgument(tree.getArguments().get(0), state));
fix.replace(tree, rewriteArrayArgument(tree.getArguments().get(0), state));
} else if (instanceHashCodeMethodMatcher.matches(tree, state)) {
// Rewrite call to instance hashCode method to use Arrays.hashCode/deepHashCode instead.
fix =
SuggestedFix.builder()
.replace(
tree,
rewriteArrayArgument(
((JCFieldAccess) tree.getMethodSelect()).getExpression(), state));
fix.replace(
tree,
rewriteArrayArgument(((JCFieldAccess) tree.getMethodSelect()).getExpression(), state));
} else if (varargsHashCodeMethodMatcher.matches(tree, state)) {
// Varargs hash code methods, java.util.Objects#hash and
// com.google.common.base.Objects#hashCode
Expand All @@ -105,22 +100,21 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
// Types like Object[], String[], etc. are not an error because they don't get boxed
// in this single-argument varargs call.
ExpressionTree arg = tree.getArguments().get(0);
Type elemType = types.elemtype(ASTHelpers.getType(arg));
Type elemType = types.elemtype(getType(arg));
if (elemType.isPrimitive() || types.isArray(elemType)) {
fix = SuggestedFix.builder().replace(tree, rewriteArrayArgument(arg, state));
fix.replace(tree, rewriteArrayArgument(arg, state));
}
} else {
// If more than one argument, wrap each argument in a call to Arrays#hashCode/deepHashCode.
fix = SuggestedFix.builder();
for (ExpressionTree arg : tree.getArguments()) {
if (types.isArray(ASTHelpers.getType(arg))) {
if (types.isArray(getType(arg))) {
fix.replace(arg, rewriteArrayArgument(arg, state));
}
}
}
}

if (fix != null) {
if (!fix.isEmpty()) {
fix.addImport("java.util.Arrays");
return describeMatch(tree, fix.build());
}
Expand All @@ -135,7 +129,7 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
*/
private static String rewriteArrayArgument(ExpressionTree arg, VisitorState state) {
Types types = state.getTypes();
Type argType = ASTHelpers.getType(arg);
Type argType = getType(arg);
Preconditions.checkState(types.isArray(argType), "arg must be of array type");
if (types.isArray(types.elemtype(argType))) {
return "Arrays.deepHashCode(" + state.getSourceForNode(arg) + ")";
Expand Down
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