Fix null pointer exception in FieldMatchers by accounting for primitive class literals

check_api/src/main/java/com/google/errorprone/matchers/FieldMatchers.java

@@ -90,9 +90,11 @@ private boolean isSymbolFieldInAppropriateClass(@Nullable Symbol symbol) {
       if (symbol == null) {
         return false;
       }
+      ClassSymbol classSymbol = enclosingClass(symbol);
       return symbol.getKind().isField()
+          && classSymbol != null
           && fieldSymbolIsAppropriate(symbol)
-          && classIsAppropriate(enclosingClass(symbol));
+          && classIsAppropriate(classSymbol);
     }
 
     abstract boolean fieldSymbolIsAppropriate(Symbol symbol);

core/src/test/java/com/google/errorprone/matchers/FieldMatchersTest.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2026 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.matchers;
+
+import static com.google.common.truth.Truth.assertWithMessage;
+
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.scanner.Scanner;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MemberSelectTree;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class FieldMatchersTest extends CompilerBasedAbstractTest {
+
+  @Test
+  public void compilesWithPrimitiveClassLiteral() {
+    writeFile(
+        "A.java",
+        """
+        class A {
+          Class<?> clazz = long.class;
+        }
+        """);
+
+    assertCompiles(
+        memberSelectMatches(
+            /* shouldMatch= */ false, FieldMatchers.anyFieldInClass("A")));
+    assertCompiles(
+            memberSelectMatches(
+                    /* shouldMatch= */ false, FieldMatchers.instanceField("A", "irrelevant")));
+    assertCompiles(
+            memberSelectMatches(
+                    /* shouldMatch= */ false, FieldMatchers.staticField("A", "irrelevant")));
+  }
+
+  private static Scanner memberSelectMatches(
+      boolean shouldMatch, Matcher<ExpressionTree> matcher) {
+    return new Scanner() {
+      @Override
+      public Void visitMemberSelect(MemberSelectTree node, VisitorState visitorState) {
+        assertWithMessage(node.toString())
+            .that(matcher.matches(node, visitorState))
+            .isEqualTo(shouldMatch);
+        return super.visitMemberSelect(node, visitorState);
+      }
+    };
+  }
+}