From 62aa8ce107e4ccec1d54a7e7701bfa83e4e0e48b Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <awilkinson@pivotal.io>
Date: Tue, 30 Jun 2020 11:27:32 +0100
Subject: [PATCH] Support incremental annotation processing with Gradle

Closes gh-22150
---
 .../gradle/incremental.annotation.processors  |  1 +
 .../fieldvalues/javac/Trees.java              | 22 ++++++++++++++-----
 .../gradle/incremental.annotation.processors  |  1 +
 3 files changed, 19 insertions(+), 5 deletions(-)
 create mode 100644 spring-boot-project/spring-boot-tools/spring-boot-autoconfigure-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors
 create mode 100644 spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors

diff --git a/spring-boot-project/spring-boot-tools/spring-boot-autoconfigure-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors b/spring-boot-project/spring-boot-tools/spring-boot-autoconfigure-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors
new file mode 100644
index 00000000000..242b07c64b5
--- /dev/null
+++ b/spring-boot-project/spring-boot-tools/spring-boot-autoconfigure-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors
@@ -0,0 +1 @@
+org.springframework.boot.autoconfigureprocessor.AutoConfigureAnnotationProcessor,aggregating
\ No newline at end of file
diff --git a/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/fieldvalues/javac/Trees.java b/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/fieldvalues/javac/Trees.java
index c958203d989..f635b8e9701 100644
--- a/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/fieldvalues/javac/Trees.java
+++ b/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/fieldvalues/javac/Trees.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.configurationprocessor.fieldvalues.javac;
 
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 
 import javax.annotation.processing.ProcessingEnvironment;
@@ -38,10 +39,21 @@ final class Trees extends ReflectionWrapper {
 	}
 
 	static Trees instance(ProcessingEnvironment env) throws Exception {
-		ClassLoader classLoader = env.getClass().getClassLoader();
-		Class<?> type = findClass(classLoader, "com.sun.source.util.Trees");
-		Method method = findMethod(type, "instance", ProcessingEnvironment.class);
-		return new Trees(method.invoke(null, env));
+		try {
+			ClassLoader classLoader = env.getClass().getClassLoader();
+			Class<?> type = findClass(classLoader, "com.sun.source.util.Trees");
+			Method method = findMethod(type, "instance", ProcessingEnvironment.class);
+			return new Trees(method.invoke(null, env));
+		}
+		catch (Exception ex) {
+			return instance(unwrap(env));
+		}
+	}
+
+	private static ProcessingEnvironment unwrap(ProcessingEnvironment wrapper) throws Exception {
+		Field delegateField = wrapper.getClass().getDeclaredField("delegate");
+		delegateField.setAccessible(true);
+		return (ProcessingEnvironment) delegateField.get(wrapper);
 	}
 
 }
diff --git a/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors b/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors
new file mode 100644
index 00000000000..cd04b210b1d
--- /dev/null
+++ b/spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/resources/META-INF/gradle/incremental.annotation.processors
@@ -0,0 +1 @@
+org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor,aggregating
\ No newline at end of file