Introduce a NativeDetector utility class

With the introduction of the -H:+InlineBeforeAnalysis native image
compiler flag in GraalVM 21.0.0, it is now possible to use an utility method and get code
removal at build time.

This flag will be enabled as of Spring Native 0.9.0.

closes gh-25795

spring-aop/src/main/java/org/springframework/aop/framework/DefaultAopProxyFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import java.io.Serializable;
 import java.lang.reflect.Proxy;
 
 import org.springframework.aop.SpringProxy;
+import org.springframework.core.NativeDetector;
 
 /**
  * Default {@link AopProxyFactory} implementation, creating either a CGLIB proxy
@@ -47,17 +48,10 @@ import org.springframework.aop.SpringProxy;
 @SuppressWarnings("serial")
 public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
 
 	@Override
 	public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
-		if (!IN_NATIVE_IMAGE &&
+		if (!NativeDetector.inNativeImage() &&
 				(config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config))) {
 			Class<?> targetClass = config.getTargetClass();
 			if (targetClass == null) {

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -73,6 +73,7 @@ import org.springframework.beans.factory.config.TypedStringValue;
 import org.springframework.core.DefaultParameterNameDiscoverer;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.NamedThreadLocal;
+import org.springframework.core.NativeDetector;
 import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.core.PriorityOrdered;
 import org.springframework.core.ResolvableType;
@@ -123,14 +124,6 @@ import org.springframework.util.StringUtils;
 public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFactory
 		implements AutowireCapableBeanFactory {
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
-
 	/** Strategy for creating bean instances. */
 	private InstantiationStrategy instantiationStrategy;
 
@@ -184,7 +177,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 		ignoreDependencyInterface(BeanNameAware.class);
 		ignoreDependencyInterface(BeanFactoryAware.class);
 		ignoreDependencyInterface(BeanClassLoaderAware.class);
-		if (IN_NATIVE_IMAGE) {
+		if (NativeDetector.inNativeImage()) {
 			this.instantiationStrategy = new SimpleInstantiationStrategy();
 		}
 		else {

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,6 +52,7 @@ import org.springframework.context.ApplicationStartupAware;
 import org.springframework.context.EnvironmentAware;
 import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.ConfigurationClassEnhancer.EnhancedConfiguration;
+import org.springframework.core.NativeDetector;
 import org.springframework.core.Ordered;
 import org.springframework.core.PriorityOrdered;
 import org.springframework.core.env.Environment;
@@ -104,13 +105,6 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 	private static final String IMPORT_REGISTRY_BEAN_NAME =
 			ConfigurationClassPostProcessor.class.getName() + ".importRegistry";
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
 
 	private final Log logger = LogFactory.getLog(getClass());
 
@@ -427,7 +421,7 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 				configBeanDefs.put(beanName, (AbstractBeanDefinition) beanDef);
 			}
 		}
-		if (configBeanDefs.isEmpty() || IN_NATIVE_IMAGE) {
+		if (configBeanDefs.isEmpty() || NativeDetector.inNativeImage()) {
 			// nothing to enhance -> return immediately
 			enhanceConfigClasses.end();
 			return;

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,6 +66,7 @@ import org.springframework.context.event.SimpleApplicationEventMulticaster;
 import org.springframework.context.expression.StandardBeanExpressionResolver;
 import org.springframework.context.weaving.LoadTimeWeaverAware;
 import org.springframework.context.weaving.LoadTimeWeaverAwareProcessor;
+import org.springframework.core.NativeDetector;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.SpringProperties;
 import org.springframework.core.annotation.AnnotationUtils;
@@ -164,13 +165,6 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 */
 	private static final boolean shouldIgnoreSpel = SpringProperties.getFlag("spring.spel.ignore");
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
 
 	static {
 		// Eagerly load the ContextClosedEvent class to avoid weird classloader issues
@@ -711,7 +705,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));
 
 		// Detect a LoadTimeWeaver and prepare for weaving, if found.
-		if (!IN_NATIVE_IMAGE && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
+		if (!NativeDetector.inNativeImage() && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
 			beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
 			// Set a temporary ClassLoader for type matching.
 			beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
@@ -752,7 +746,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 
 		// Detect a LoadTimeWeaver and prepare for weaving, if found in the meantime
 		// (e.g. through an @Bean method registered by ConfigurationClassPostProcessor)
-		if (!IN_NATIVE_IMAGE && beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
+		if (!NativeDetector.inNativeImage() && beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
 			beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
 			beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
 		}
@@ -943,7 +937,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		publishEvent(new ContextRefreshedEvent(this));
 
 		// Participate in LiveBeansView MBean, if active.
-		if (!IN_NATIVE_IMAGE) {
+		if (!NativeDetector.inNativeImage()) {
 			LiveBeansView.registerApplicationContext(this);
 		}
 	}
@@ -1054,7 +1048,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 				logger.debug("Closing " + this);
 			}
 
-			if (!IN_NATIVE_IMAGE) {
+			if (!NativeDetector.inNativeImage()) {
 				LiveBeansView.unregisterApplicationContext(this);
 			}
 

spring-core/src/main/java/org/springframework/core/DefaultParameterNameDiscoverer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,15 +39,9 @@ package org.springframework.core;
  */
 public class DefaultParameterNameDiscoverer extends PrioritizedParameterNameDiscoverer {
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
 	public DefaultParameterNameDiscoverer() {
-		if (KotlinDetector.isKotlinReflectPresent() && !IN_NATIVE_IMAGE) {
+		// TODO Remove this conditional inclusion when upgrading to Kotlin 1.5, see https://youtrack.jetbrains.com/issue/KT-44594
+		if (KotlinDetector.isKotlinReflectPresent() && !NativeDetector.inNativeImage()) {
 			addDiscoverer(new KotlinReflectionParameterNameDiscoverer());
 		}
 		addDiscoverer(new StandardReflectionParameterNameDiscoverer());

spring-core/src/main/java/org/springframework/core/NativeDetector.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2002-2021 the original author or 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
+ *
+ *      https://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 org.springframework.core;
+
+/**
+ * A common delegate for detecting a GraalVM native image environment.
+ *
+ * <p>Requires using the {@code -H:+InlineBeforeAnalysis} native image compiler flag in order to allow code removal at
+ * build time.
+ *
+ * @author Sebastien Deleuze
+ * @since 5.3.4
+ */
+public abstract class NativeDetector {
+
+	// See https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java
+	private static final boolean imageCode = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
+
+	/**
+	 * Returns {@code true} if invoked in the context of image building or during image runtime, else {@code false}.
+	 */
+	public static boolean inNativeImage() {
+		return imageCode;
+	}
+}

spring-core/src/main/java/org/springframework/core/SerializableTypeWrapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -59,13 +59,6 @@ final class SerializableTypeWrapper {
 	private static final Class<?>[] SUPPORTED_SERIALIZABLE_TYPES = {
 			GenericArrayType.class, ParameterizedType.class, TypeVariable.class, WildcardType.class};
 
-	/**
-	 * Whether this environment lives within a native image.
-	 * Exposed as a private static field rather than in a {@code NativeImageDetector.inNativeImage()} static method due to https://github.com/oracle/graal/issues/2594.
-	 * @see <a href="https://github.com/oracle/graal/blob/master/sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/ImageInfo.java">ImageInfo.java</a>
-	 */
-	private static final boolean IN_NATIVE_IMAGE = (System.getProperty("org.graalvm.nativeimage.imagecode") != null);
-
 	static final ConcurrentReferenceHashMap<Type, Type> cache = new ConcurrentReferenceHashMap<>(256);
 
 
@@ -116,7 +109,7 @@ final class SerializableTypeWrapper {
 			// No serializable type wrapping necessary (e.g. for java.lang.Class)
 			return providedType;
 		}
-		if (IN_NATIVE_IMAGE || !Serializable.class.isAssignableFrom(Class.class)) {
+		if (NativeDetector.inNativeImage() || !Serializable.class.isAssignableFrom(Class.class)) {
 			// Let's skip any wrapping attempts if types are generally not serializable in
 			// the current runtime environment (even java.lang.Class itself, e.g. on GraalVM native images)
 			return providedType;