Open com.sun.tools.javac modules on JDK 16+

CHANGES.md

@@ -12,6 +12,8 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Added
 * Support for `editorConfigOverride` in `ktlint`. ([#1218](https://github.com/diffplug/spotless/pull/1218) fixes [#1193](https://github.com/diffplug/spotless/issues/1193))
+### Fixed
+* `google-java-format` and `RemoveUnusedImportsStep` works on JDK16+ without jvm args workaround. ([#1224](https://github.com/diffplug/spotless/pull/1224) fixes [#834](https://github.com/diffplug/spotless/issues/834))
 
 ## [2.25.3] - 2022-05-10
 ### Fixed

lib/src/main/java/com/diffplug/spotless/Jvm.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 DiffPlug
+ * Copyright 2016-2022 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

lib/src/main/java/com/diffplug/spotless/java/GoogleJavaFormatStep.java

@@ -136,6 +136,7 @@ static final class State implements Serializable {
 
 		State(String stepName, String groupArtifact, String version, String style, Provisioner provisioner, boolean reflowLongStrings) throws Exception {
 			JVM_SUPPORT.assertFormatterSupported(version);
+			ModuleHelper.doOpenInternalPackagesIfRequired();
 			this.jarState = JarState.from(groupArtifact + ":" + version, provisioner);
 			this.stepName = stepName;
 			this.version = version;

lib/src/main/java/com/diffplug/spotless/java/ModuleHelper.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright 2016-2022 DiffPlug
+ *
+ * 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.diffplug.spotless.java;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.annotation.Nullable;
+
+import com.diffplug.spotless.Jvm;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import sun.misc.Unsafe;
+
+final class ModuleHelper {
+	// prevent direct instantiation
+	private ModuleHelper() {}
+
+	private static final Map<String, String> REQUIRED_PACKAGES_TO_TEST_CLASSES = new HashMap<>();
+
+	static {
+		REQUIRED_PACKAGES_TO_TEST_CLASSES.putIfAbsent("com.sun.tools.javac.util", "Context");
+		REQUIRED_PACKAGES_TO_TEST_CLASSES.putIfAbsent("com.sun.tools.javac.file", "CacheFSInfo");
+		REQUIRED_PACKAGES_TO_TEST_CLASSES.putIfAbsent("com.sun.tools.javac.tree", "TreeTranslator");
+		REQUIRED_PACKAGES_TO_TEST_CLASSES.putIfAbsent("com.sun.tools.javac.parser", "Tokens$TokenKind");
+		REQUIRED_PACKAGES_TO_TEST_CLASSES.putIfAbsent("com.sun.tools.javac.api", "DiagnosticFormatter$PositionKind");
+	}
+
+	private static boolean checkDone = false;
+
+	public static synchronized void doOpenInternalPackagesIfRequired() {
+		if (Jvm.version() < 16 || checkDone) {
+			return;
+		}
+		try {
+			checkDone = true;
+			final List<String> unavailableRequiredPackages = unavailableRequiredPackages();
+			if (!unavailableRequiredPackages.isEmpty()) {
+				openPackages(unavailableRequiredPackages);
+				final List<String> failedToOpen = unavailableRequiredPackages();
+				if (!failedToOpen.isEmpty()) {
+					final StringBuilder message = new StringBuilder();
+					message.append("WARNING: Some required internal classes are unavailable. Please consider adding the following JVM arguments\n");
+					message.append("WARNING: ");
+					for (String name : failedToOpen) {
+						message.append(String.format("--add-opens jdk.compiler/%s=ALL-UNNAMED", name));
+					}
+					System.err.println(message);
+				}
+			}
+		} catch (Throwable e) {
+			System.err.println("WARNING: Failed to check for unavailable JDK packages. Reason: " + e.getMessage());
+		}
+	}
+
+	@SuppressFBWarnings("REC_CATCH_EXCEPTION") // workaround JDK11
+	private static List<String> unavailableRequiredPackages() {
+		final List<String> packages = new ArrayList<>();
+		for (Map.Entry<String, String> e : REQUIRED_PACKAGES_TO_TEST_CLASSES.entrySet()) {
+			final String key = e.getKey();
+			final String value = e.getValue();
+			try {
+				final Class<?> clazz = Class.forName(key + "." + value);
+				if (clazz.isEnum()) {
+					clazz.getMethod("values").invoke(null);
+				} else {
+					clazz.getDeclaredConstructor().newInstance();
+				}
+			} catch (IllegalAccessException ex) {
+				packages.add(key);
+			} catch (Exception ignore) {
+				// in old versions of JDK some classes could be unavailable
+			}
+		}
+		return packages;
+	}
+
+	@SuppressWarnings("unchecked")
+	private static void openPackages(Collection<String> packagesToOpen) throws Throwable {
+		final Collection<?> modules = allModules();
+		if (modules == null) {
+			return;
+		}
+		final Unsafe unsafe = Unsafe.getUnsafe();
+		final Field implLookupField = MethodHandles.Lookup.class.getDeclaredField("IMPL_LOOKUP");
+		final MethodHandles.Lookup lookup = (MethodHandles.Lookup) unsafe.getObject(
+				unsafe.staticFieldBase(implLookupField),
+				unsafe.staticFieldOffset(implLookupField));
+		final MethodHandle modifiers = lookup.findSetter(Method.class, "modifiers", Integer.TYPE);
+		final Method exportMethod = Class.forName("java.lang.Module").getDeclaredMethod("implAddOpens", String.class);
+		modifiers.invokeExact(exportMethod, Modifier.PUBLIC);
+		for (Object module : modules) {
+			final Collection<String> packages = (Collection<String>) module.getClass().getMethod("getPackages").invoke(module);
+			for (String name : packages) {
+				if (packagesToOpen.contains(name)) {
+					exportMethod.invoke(module, name);
+				}
+			}
+		}
+	}
+
+	@Nullable
+	@SuppressFBWarnings("REC_CATCH_EXCEPTION") // workaround JDK11
+	private static Collection<?> allModules() {
+		// calling ModuleLayer.boot().modules() by reflection
+		try {
+			final Object boot = Class.forName("java.lang.ModuleLayer").getMethod("boot").invoke(null);
+			if (boot == null) {
+				return null;
+			}
+			final Object modules = boot.getClass().getMethod("modules").invoke(boot);
+			return (Collection<?>) modules;
+		} catch (Exception ignore) {
+			return null;
+		}
+	}
+}

plugin-gradle/CHANGES.md

@@ -6,6 +6,9 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ### Added
 * Support for `editorConfigOverride` in `ktlint`. ([#1218](https://github.com/diffplug/spotless/pull/1218) fixes [#1193](https://github.com/diffplug/spotless/issues/1193))
   * If you are using properties like `indent_size`, you should pass now pass them as `editorConfigOverride` and not as `userData`.
+### Fixed
+* `googleJavaFormat` and `removeUnusedImports` works on JDK16+ without jvm args workaround. ([#1224](https://github.com/diffplug/spotless/pull/1224))
+  * If you have a bunch of `--add-exports` calls in your `org.gradle.jvmargs` property in `gradle.properties`, you should be able to remove them. (fixes [#834](https://github.com/diffplug/spotless/issues/834#issuecomment-819118761))
 
 ## [6.6.1] - 2022-05-13
 ### Fixed

plugin-maven/CHANGES.md

@@ -3,6 +3,9 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Fixed
+* `googleJavaFormat` and `removeUnusedImports` works on JDK16+ without jvm args workaround. ([#1224](https://github.com/diffplug/spotless/pull/1224))
+  * If you have a bunch of `--add-exports` calls in `MAVEN_OPTS` or `.mvn/jvm.config`, you should be able to remove them. (fixes [#834](https://github.com/diffplug/spotless/issues/834#issuecomment-817524058))
 
 ## [2.22.5] - 2022-05-10
 ### Fixed