Add support for specifying compiler options

This commit is a prerequisite to help suppressing deprecating warnings
by allowing tests to validate that the compiler does not encounter them.

See gh-29597

spring-core-test/src/main/java/org/springframework/core/test/tools/TestCompiler.java

@@ -24,6 +24,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.function.Consumer;
 import java.util.function.UnaryOperator;
+import java.util.stream.Stream;
 
 import javax.annotation.processing.Processor;
 import javax.tools.Diagnostic;
@@ -41,6 +42,7 @@ import org.springframework.lang.Nullable;
  *
  * @author Phillip Webb
  * @author Scott Frederick
+ * @author Stephane Nicoll
  * @since 6.0
  * @see #forSystem()
  */
@@ -59,10 +61,12 @@ public final class TestCompiler {
 
 	private final List<Processor> processors;
 
+	private final List<String> compilerOptions;
+
 
 	private TestCompiler(@Nullable ClassLoader classLoader, JavaCompiler compiler,
 			SourceFiles sourceFiles, ResourceFiles resourceFiles, ClassFiles classFiles,
-			List<Processor> processors) {
+			List<Processor> processors, List<String> compilerOptions) {
 
 		this.classLoader = classLoader;
 		this.compiler = compiler;
@@ -70,6 +74,7 @@ public final class TestCompiler {
 		this.resourceFiles = resourceFiles;
 		this.classFiles = classFiles;
 		this.processors = processors;
+		this.compilerOptions = compilerOptions;
 	}
 
 
@@ -88,7 +93,7 @@ public final class TestCompiler {
 	 */
 	public static TestCompiler forCompiler(JavaCompiler javaCompiler) {
 		return new TestCompiler(null, javaCompiler, SourceFiles.none(),
-				ResourceFiles.none(), ClassFiles.none(), Collections.emptyList());
+				ResourceFiles.none(), ClassFiles.none(), Collections.emptyList(), Collections.emptyList());
 	}
 
 	/**
@@ -108,7 +113,7 @@ public final class TestCompiler {
 	public TestCompiler withSources(SourceFile... sourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler,
 				this.sourceFiles.and(sourceFiles), this.resourceFiles,
-				this.classFiles, this.processors);
+				this.classFiles, this.processors, this.compilerOptions);
 	}
 
 	/**
@@ -119,7 +124,7 @@ public final class TestCompiler {
 	public TestCompiler withSources(Iterable<SourceFile> sourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler,
 				this.sourceFiles.and(sourceFiles), this.resourceFiles,
-				this.classFiles, this.processors);
+				this.classFiles, this.processors, this.compilerOptions);
 	}
 
 	/**
@@ -130,7 +135,7 @@ public final class TestCompiler {
 	public TestCompiler withSources(SourceFiles sourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler,
 				this.sourceFiles.and(sourceFiles), this.resourceFiles,
-				this.classFiles, this.processors);
+				this.classFiles, this.processors, this.compilerOptions);
 	}
 
 	/**
@@ -140,7 +145,8 @@ public final class TestCompiler {
 	 */
 	public TestCompiler withResources(ResourceFile... resourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors);
+				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors,
+				this.compilerOptions);
 	}
 
 	/**
@@ -150,7 +156,8 @@ public final class TestCompiler {
 	 */
 	public TestCompiler withResources(Iterable<ResourceFile> resourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors);
+				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors,
+				this.compilerOptions);
 	}
 
 	/**
@@ -160,7 +167,8 @@ public final class TestCompiler {
 	 */
 	public TestCompiler withResources(ResourceFiles resourceFiles) {
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors);
+				this.resourceFiles.and(resourceFiles), this.classFiles, this.processors,
+				this.compilerOptions);
 	}
 
 	/**
@@ -170,7 +178,8 @@ public final class TestCompiler {
 	 */
 	public TestCompiler withClasses(Iterable<ClassFile> classFiles) {
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles, this.classFiles.and(classFiles), this.processors);
+				this.resourceFiles, this.classFiles.and(classFiles), this.processors,
+				this.compilerOptions);
 	}
 
 	/**
@@ -182,7 +191,7 @@ public final class TestCompiler {
 		List<Processor> mergedProcessors = new ArrayList<>(this.processors);
 		mergedProcessors.addAll(Arrays.asList(processors));
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles, this.classFiles, mergedProcessors);
+				this.resourceFiles, this.classFiles, mergedProcessors, this.compilerOptions);
 	}
 
 	/**
@@ -194,7 +203,32 @@ public final class TestCompiler {
 		List<Processor> mergedProcessors = new ArrayList<>(this.processors);
 		processors.forEach(mergedProcessors::add);
 		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
-				this.resourceFiles, this.classFiles, mergedProcessors);
+				this.resourceFiles, this.classFiles, mergedProcessors, this.compilerOptions);
+	}
+
+	/**
+	 * Create a new {@link TestCompiler} instance with the additional compiler options.
+	 * @param options the additional compiler options
+	 * @return a new {@code TestCompiler} instance
+	 * @since 6.1
+	 */
+	public TestCompiler withCompilerOptions(String... options) {
+		List<String> mergedCompilerOptions = Stream.concat(this.compilerOptions.stream(),
+				Arrays.stream(options)).distinct().toList();
+		return new TestCompiler(this.classLoader, this.compiler, this.sourceFiles,
+				this.resourceFiles, this.classFiles, this.processors, mergedCompilerOptions);
+	}
+
+	/**
+	 * Create a new {@link TestCompiler} instance that fails if any warning is
+	 * encountered. This sets the {@code -Xlint:all} and {@code -Werror} compiler
+	 * options.
+	 * @return a new {@code TestCompiler} instance
+	 * @since 6.1
+	 * @see #withCompilerOptions(String...)
+	 */
+	public TestCompiler failOnWarning() {
+		return withCompilerOptions("-Xlint:all", "-Werror");
 	}
 
 	/**
@@ -275,8 +309,8 @@ public final class TestCompiler {
 				standardFileManager, classLoaderToUse, this.classFiles, this.resourceFiles);
 		if (!this.sourceFiles.isEmpty()) {
 			Errors errors = new Errors();
-			CompilationTask task = this.compiler.getTask(null, fileManager, errors, null,
-					null, compilationUnits);
+			CompilationTask task = this.compiler.getTask(null, fileManager, errors,
+					this.compilerOptions, null, compilationUnits);
 			if (!this.processors.isEmpty()) {
 				task.setProcessors(this.processors);
 			}

spring-core-test/src/test/java/org/springframework/core/test/tools/TestCompilerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * 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.
@@ -43,6 +43,7 @@ import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  * @author Phillip Webb
  * @author Andy Wilkinson
  * @author Scott Frederick
+ * @author Stephane Nicoll
  */
 class TestCompilerTests {
 
@@ -87,6 +88,20 @@ class TestCompilerTests {
 			}
 			""";
 
+	private static final String HELLO_DEPRECATED = """
+			package com.example;
+
+			import java.util.function.Supplier;
+
+			public class Hello implements Supplier<String> {
+
+				@Deprecated
+				public String get() {
+					return "Hello Deprecated";
+				}
+
+			}
+			""";
 
 	@Test
 	@SuppressWarnings("unchecked")
@@ -119,6 +134,70 @@ class TestCompilerTests {
 				}));
 	}
 
+	@Test
+	@SuppressWarnings("unchecked")
+	void compileWhenSourceUseDeprecateCodeAndNoOptionSet() {
+		SourceFile main = SourceFile.of("""
+				package com.example;
+
+				public class Main {
+
+					public static void main(String[] args) {
+						new Hello().get();
+					}
+
+				}
+				""");
+		TestCompiler.forSystem().withSources(
+				SourceFile.of(HELLO_DEPRECATED), main).compile(compiled -> {
+			Supplier<String> supplier = compiled.getInstance(Supplier.class,
+					"com.example.Hello");
+			assertThat(supplier.get()).isEqualTo("Hello Deprecated");
+		});
+	}
+
+	@Test
+	void compileWhenSourceUseDeprecateCodeAndFailOnWarningIsSet() {
+		SourceFile main = SourceFile.of("""
+				package com.example;
+
+				public class Main {
+
+					public static void main(String[] args) {
+						new Hello().get();
+					}
+
+				}
+				""");
+		assertThatExceptionOfType(CompilationException.class).isThrownBy(
+				() -> TestCompiler.forSystem().failOnWarning().withSources(
+						SourceFile.of(HELLO_DEPRECATED), main).compile(compiled -> {
+				})).withMessageContaining("warnings found and -Werror specified");
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	void compileWhenSourceUseDeprecateCodeAndFailOnWarningWithSuppressWarnings() {
+		SourceFile main = SourceFile.of("""
+				package com.example;
+
+				public class Main {
+
+					@SuppressWarnings("deprecation")
+					public static void main(String[] args) {
+						new Hello().get();
+					}
+
+				}
+				""");
+		TestCompiler.forSystem().failOnWarning().withSources(
+				SourceFile.of(HELLO_DEPRECATED), main).compile(compiled -> {
+			Supplier<String> supplier = compiled.getInstance(Supplier.class,
+					"com.example.Hello");
+			assertThat(supplier.get()).isEqualTo("Hello Deprecated");
+		});
+	}
+
 	@Test
 	void withSourcesArrayAddsSource() {
 		SourceFile sourceFile = SourceFile.of(HELLO_WORLD);