Fix jdk17 incompatibility of ClassInitializationDeadlock

baseline-error-prone/src/main/java/com/palantir/baseline/errorprone/BaselineErrorProneScope.java

@@ -0,0 +1,110 @@
+/*
+ * (c) Copyright 2021 Palantir Technologies Inc. All rights reserved.
+ *
+ * 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.palantir.baseline.errorprone;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.errorprone.util.RuntimeVersion;
+import com.sun.tools.javac.code.Scope;
+import com.sun.tools.javac.code.Scope.LookupKind;
+import com.sun.tools.javac.code.Symbol;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.Arrays;
+import java.util.function.Predicate;
+
+/**
+ * A compatibility wrapper around {@link com.sun.tools.javac.util.Filter}.
+ * Adapted from {@link com.google.errorprone.util.ErrorProneScope} with additional methods.
+ *
+ * Original code from (Apache-2.0 License):
+ * https://github.com/google/error-prone/blob/ce87ca1c7bb005371837b82ffa69041dd8a356e5/check_api/src/main/java/com/google/errorprone/util/ErrorProneScope.java
+ *
+ * TODO(fwindheuser): Delete after upstreaming missing methods into "ErrorProneScope".
+ */
+@SuppressWarnings("ThrowError")
+public final class BaselineErrorProneScope {
+
+    @SuppressWarnings("unchecked") // reflection
+    public Iterable<Symbol> getSymbols(Predicate<Symbol> predicate, LookupKind lookupKind) {
+        return (Iterable<Symbol>) invoke(getSymbols, maybeAsFilter(predicate), lookupKind);
+    }
+
+    private static final Class<?> FILTER_CLASS = getFilterClass();
+
+    private static Class<?> getFilterClass() {
+        if (RuntimeVersion.isAtLeast17()) {
+            return null;
+        }
+        try {
+            return Class.forName("com.sun.tools.javac.util.Filter");
+        } catch (ClassNotFoundException e) {
+            throw new LinkageError(e.getMessage(), e);
+        }
+    }
+
+    private static final Method getSymbols = getImpl("getSymbols", Predicate.class, LookupKind.class);
+
+    private static Method getImpl(String name, Class<?>... parameters) {
+        return FILTER_CLASS != null
+                ? getMethodOrDie(
+                        Scope.class,
+                        name,
+                        Arrays.stream(parameters)
+                                .map(p -> p.equals(Predicate.class) ? FILTER_CLASS : p)
+                                .toArray(Class<?>[]::new))
+                : getMethodOrDie(Scope.class, name, parameters);
+    }
+
+    private final Scope scope;
+
+    BaselineErrorProneScope(Scope scope) {
+        this.scope = scope;
+    }
+
+    private Object invoke(Method method, Object... args) {
+        try {
+            return method.invoke(scope, args);
+        } catch (ReflectiveOperationException e) {
+            throw new LinkageError(e.getMessage(), e);
+        }
+    }
+
+    @SuppressWarnings("ProxyNonConstantType")
+    private Object maybeAsFilter(Predicate<Symbol> predicate) {
+        if (FILTER_CLASS == null) {
+            return predicate;
+        }
+        return Proxy.newProxyInstance(
+                getClass().getClassLoader(), new Class<?>[] {FILTER_CLASS}, new InvocationHandler() {
+                    @Override
+                    public Object invoke(Object proxy, Method method, Object[] args) {
+                        checkState(method.getName().equals("accepts"));
+                        return predicate.test((Symbol) args[0]);
+                    }
+                });
+    }
+
+    private static Method getMethodOrDie(Class<?> clazz, String name, Class<?>... parameters) {
+        try {
+            return clazz.getMethod(name, parameters);
+        } catch (NoSuchMethodException e) {
+            throw new LinkageError(e.getMessage(), e);
+        }
+    }
+}

baseline-error-prone/src/main/java/com/palantir/baseline/errorprone/ClassInitializationDeadlock.java

@@ -41,7 +41,6 @@
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
 import com.sun.tools.javac.code.Symbol.VarSymbol;
 import com.sun.tools.javac.code.Type;
-import com.sun.tools.javac.util.Filter;
 
 @AutoService(BugChecker.class)
 @BugPattern(
@@ -130,9 +129,8 @@ private boolean cannotBeInitializedExternally(ClassSymbol newClassSymbol) {
             if (newClassSymbol.isPrivate()) {
                 return true;
             }
-            return !newClassSymbol
-                    .members()
-                    .getSymbols(CanBeExternallyInitializedFilter.INSTANCE, LookupKind.NON_RECURSIVE)
+            return !new BaselineErrorProneScope(newClassSymbol.members())
+                    .getSymbols(ClassInitializationDeadlock::canBeExternallyInitialized, LookupKind.NON_RECURSIVE)
                     .iterator()
                     .hasNext();
         }
@@ -229,28 +227,23 @@ private static boolean isSubtype(Type maybeSubtype, Type baseType, VisitorState
                 && !ASTHelpers.isSameType(maybeSubtype, baseType, state);
     }
 
-    private enum CanBeExternallyInitializedFilter implements Filter<Symbol> {
-        INSTANCE;
-
-        @Override
-        public boolean accepts(Symbol symbol) {
-            switch (symbol.getKind()) {
-                case FIELD:
-                    // fall through
-                case METHOD:
-                    if (symbol.isStatic() && !symbol.isPrivate()) {
-                        return true;
-                    }
-                    break;
-                case CONSTRUCTOR:
-                    if (!symbol.isPrivate()) {
-                        return true;
-                    }
-                    break;
-                default:
-                    // fall through
-            }
-            return false;
+    private static boolean canBeExternallyInitialized(Symbol symbol) {
+        switch (symbol.getKind()) {
+            case FIELD:
+                // fall through
+            case METHOD:
+                if (symbol.isStatic() && !symbol.isPrivate()) {
+                    return true;
+                }
+                break;
+            case CONSTRUCTOR:
+                if (!symbol.isPrivate()) {
+                    return true;
+                }
+                break;
+            default:
+                // fall through
         }
+        return false;
     }
 }

changelog/@unreleased/pr-1936.v2.yml

@@ -0,0 +1,5 @@
+type: fix
+fix:
+  description: Fix jdk17 incompatibility of ClassInitializationDeadlock
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/1936