org.springframework.aot.nativex.feature.PreComputeFieldFeature Maven / Gradle / Ivy
/*
* Copyright 2002-2023 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.aot.nativex.feature;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.regex.Pattern;
import org.graalvm.nativeimage.hosted.Feature;
/**
* GraalVM {@link Feature} that substitutes boolean field values that match a certain pattern
* with values pre-computed AOT without causing class build-time initialization.
*
* It is possible to pass
-Dspring.native.precompute.log=verbose
as a
* native-image
compiler build argument to display detailed logs
* about pre-computed fields.
*
* @author Sebastien Deleuze
* @author Phillip Webb
* @since 6.0
*/
class PreComputeFieldFeature implements Feature {
private static final boolean verbose =
"verbose".equalsIgnoreCase(System.getProperty("spring.native.precompute.log"));
private static final Pattern[] patterns = {
Pattern.compile(Pattern.quote("org.springframework.core.NativeDetector#inNativeImage")),
Pattern.compile(Pattern.quote("org.springframework.cglib.core.AbstractClassGenerator#inNativeImage")),
Pattern.compile(Pattern.quote("org.springframework.aot.AotDetector#inNativeImage")),
Pattern.compile(Pattern.quote("org.springframework.") + ".*#.*Present"),
Pattern.compile(Pattern.quote("org.springframework.") + ".*#.*PRESENT"),
Pattern.compile(Pattern.quote("reactor.core.") + ".*#.*Available"),
Pattern.compile(Pattern.quote("org.apache.commons.logging.LogAdapter") + "#.*Present")
};
private final ThrowawayClassLoader throwawayClassLoader = new ThrowawayClassLoader(getClass().getClassLoader());
@Override
public void beforeAnalysis(BeforeAnalysisAccess access) {
access.registerSubtypeReachabilityHandler(this::iterateFields, Object.class);
}
// This method is invoked for every type that is reachable.
private void iterateFields(DuringAnalysisAccess access, Class subtype) {
try {
for (Field field : subtype.getDeclaredFields()) {
int modifiers = field.getModifiers();
if (!Modifier.isStatic(modifiers) || !Modifier.isFinal(modifiers) || field.isEnumConstant() ||
(field.getType() != boolean.class && field.getType() != Boolean.class)) {
continue;
}
String fieldIdentifier = field.getDeclaringClass().getName() + "#" + field.getName();
for (Pattern pattern : patterns) {
if (pattern.matcher(fieldIdentifier).matches()) {
try {
Object fieldValue = provideFieldValue(field);
access.registerFieldValueTransformer(field, (receiver, originalValue) -> fieldValue);
if (verbose) {
System.out.println(
"Field " + fieldIdentifier + " set to " + fieldValue + " at build time");
}
}
catch (Throwable ex) {
if (verbose) {
System.out.println("Field " + fieldIdentifier + " will be evaluated at runtime " +
"due to this error during build time evaluation: " + ex);
}
}
}
}
}
}
catch (NoClassDefFoundError ex) {
// Skip classes that have not all their field types in the classpath
}
}
// This method is invoked when the field value is written to the image heap or the field is constant folded.
private Object provideFieldValue(Field field)
throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
Class throwawayClass = this.throwawayClassLoader.loadClass(field.getDeclaringClass().getName());
Field throwawayField = throwawayClass.getDeclaredField(field.getName());
throwawayField.setAccessible(true);
return throwawayField.get(null);
}
}