Warning if <springProfile> is used in phase 2 model elements

Add `SpringProfileIfNestedWithinSecondPhaseElementSanityChecker` which
will provide a warning if `<springProfile>` is used within a phase 2
model element. This is similar to Logback's own `<if>` warnings.

The `LogbackLoggingSystem` has also been updated so that warning are
printed when present.

Fixes gh-33610

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/LogbackLoggingSystem.java

@@ -36,7 +36,9 @@
 import ch.qos.logback.core.spi.FilterReply;
 import ch.qos.logback.core.status.OnConsoleStatusListener;
 import ch.qos.logback.core.status.Status;
+import ch.qos.logback.core.status.StatusUtil;
 import ch.qos.logback.core.util.StatusListenerConfigHelper;
+import ch.qos.logback.core.util.StatusPrinter;
 import org.slf4j.ILoggerFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -250,6 +252,9 @@ protected void loadConfiguration(LoggingInitializationContext initializationCont
 		if (errors.length() > 0) {
 			throw new IllegalStateException(String.format("Logback configuration error detected: %n%s", errors));
 		}
+		if (!StatusUtil.contextHasStatusListener(loggerContext)) {
+			StatusPrinter.printInCaseOfErrorsOrWarnings(loggerContext);
+		}
 	}
 
 	private void configureByResourceUrl(LoggingInitializationContext initializationContext, LoggerContext loggerContext,

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/SpringBootJoranConfigurator.java

@@ -82,6 +82,12 @@ class SpringBootJoranConfigurator extends JoranConfigurator {
 		this.initializationContext = initializationContext;
 	}
 
+	@Override
+	protected void sanityCheck(Model topModel) {
+		super.sanityCheck(topModel);
+		performCheck(new SpringProfileIfNestedWithinSecondPhaseElementSanityChecker(), topModel);
+	}
+
 	@Override
 	protected void addModelHandlerAssociations(DefaultProcessor defaultProcessor) {
 		defaultProcessor.addHandler(SpringPropertyModel.class,

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/SpringProfileIfNestedWithinSecondPhaseElementSanityChecker.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2012-2022 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.boot.logging.logback;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import ch.qos.logback.classic.joran.sanity.IfNestedWithinSecondPhaseElementSC;
+import ch.qos.logback.classic.model.LoggerModel;
+import ch.qos.logback.classic.model.RootLoggerModel;
+import ch.qos.logback.core.joran.sanity.Pair;
+import ch.qos.logback.core.joran.sanity.SanityChecker;
+import ch.qos.logback.core.model.AppenderModel;
+import ch.qos.logback.core.model.Model;
+import ch.qos.logback.core.spi.ContextAwareBase;
+
+/**
+ * {@link SanityChecker} to ensure that {@code springProfile} elements are not nested
+ * within second-phase elements.
+ *
+ * @author Phillip Webb
+ * @see IfNestedWithinSecondPhaseElementSC
+ */
+class SpringProfileIfNestedWithinSecondPhaseElementSanityChecker extends ContextAwareBase implements SanityChecker {
+
+	private static final List<Class<? extends Model>> SECOND_PHASE_TYPES = List.of(AppenderModel.class,
+			LoggerModel.class, RootLoggerModel.class);
+
+	@Override
+	public void check(Model model) {
+		if (model == null) {
+			return;
+		}
+		List<Model> models = new ArrayList<>();
+		SECOND_PHASE_TYPES.forEach((type) -> deepFindAllModelsOfType(type, models, model));
+		List<Pair<Model, Model>> nestedPairs = deepFindNestedSubModelsOfType(SpringProfileModel.class, models);
+		if (!nestedPairs.isEmpty()) {
+			addWarn("<springProfile> elements cannot be nested within an <appender>, <logger> or <root> element");
+			nestedPairs.forEach((nested) -> {
+				Model first = nested.first;
+				Model second = nested.second;
+				addWarn("Element <%s> at line %s contains a nested <%s> element at line %s".formatted(first.getTag(),
+						first.getLineNumber(), second.getTag(), second.getLineNumber()));
+			});
+		}
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogbackLoggingSystemTests.java

@@ -38,6 +38,7 @@
 import ch.qos.logback.core.encoder.LayoutWrappingEncoder;
 import ch.qos.logback.core.rolling.RollingFileAppender;
 import ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy;
+import ch.qos.logback.core.util.StatusPrinter;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -110,6 +111,7 @@ void setup() {
 		ConversionService conversionService = ApplicationConversionService.getSharedInstance();
 		this.environment.setConversionService((ConfigurableConversionService) conversionService);
 		this.initializationContext = new LoggingInitializationContext(this.environment);
+		StatusPrinter.setPrintStream(System.out);
 	}
 
 	@AfterEach
@@ -665,6 +667,14 @@ void whenContextHasAotContributionThenProcessAheadOfTimeClearsAndReturnsIt() {
 		assertThat(contribution).isNotNull();
 	}
 
+	@Test // gh-33610
+	void springProfileIfNestedWithinSecondPhaseElementSanityChecker(CapturedOutput output) {
+		this.loggingSystem.beforeInitialize();
+		initialize(this.initializationContext, "classpath:logback-springprofile-in-root.xml", null);
+		this.logger.info("Hello world");
+		assertThat(output).contains("<springProfile> elements cannot be nested within an");
+	}
+
 	private void initialize(LoggingInitializationContext context, String configLocation, LogFile logFile) {
 		this.loggingSystem.getSystemProperties((ConfigurableEnvironment) context.getEnvironment()).apply(logFile);
 		this.loggingSystem.initialize(context, configLocation, logFile);

spring-boot-project/spring-boot/src/test/resources/logback-springprofile-in-root.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%property{LOG_FILE} [%t] ${PID:-????} %c{1}: %m%n BOOTBOOT</pattern>
+		</encoder>
+	</appender>
+	<root level="INFO">
+		<springProfile name="profile">
+			<appender-ref ref="CONSOLE" />
+		</springProfile>
+	</root>
+</configuration>