Include shadowed jar source in published source artifacts

Add a new `ShadowSource` Gradle task and update `spring-core.gradle`
to include source for cglib, javapoet and objenesis.

Closes gh-28892

Co-authored-by: Andy Wilkinson <wilkinsona@vmware.com>

buildSrc/src/main/java/org/springframework/build/shadow/ShadowSource.java

@@ -0,0 +1,175 @@
+package org.springframework.build.shadow;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.artifacts.Configuration;
+import org.gradle.api.artifacts.component.ModuleComponentSelector;
+import org.gradle.api.artifacts.query.ArtifactResolutionQuery;
+import org.gradle.api.artifacts.result.ArtifactResolutionResult;
+import org.gradle.api.artifacts.result.ComponentArtifactsResult;
+import org.gradle.api.artifacts.result.DependencyResult;
+import org.gradle.api.artifacts.result.ResolutionResult;
+import org.gradle.api.artifacts.result.ResolvedArtifactResult;
+import org.gradle.api.file.DirectoryProperty;
+import org.gradle.api.file.FileCopyDetails;
+import org.gradle.api.file.FileTree;
+import org.gradle.api.tasks.Classpath;
+import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.Nested;
+import org.gradle.api.tasks.Optional;
+import org.gradle.api.tasks.OutputDirectory;
+import org.gradle.api.tasks.TaskAction;
+import org.gradle.jvm.JvmLibrary;
+import org.gradle.language.base.artifact.SourcesArtifact;
+
+/**
+ * Gradle task to add source from shadowed jars into our own source jars.
+ *
+ * @author Phillip Webb
+ * @author Andy Wilkinson
+ */
+public class ShadowSource extends DefaultTask {
+
+	private final DirectoryProperty outputDirectory = getProject().getObjects().directoryProperty();
+
+	private List<Configuration> configurations = new ArrayList<>();
+
+	private final List<Relocation> relocations = new ArrayList<>();
+
+
+	@Classpath
+	@Optional
+	public List<Configuration> getConfigurations() {
+		return this.configurations;
+	}
+
+	public void setConfigurations(List<Configuration> configurations) {
+		this.configurations = configurations;
+	}
+
+	@Nested
+	public List<Relocation> getRelocations() {
+		return this.relocations;
+	}
+
+	public void relocate(String pattern, String destination) {
+		this.relocations.add(new Relocation(pattern, destination));
+	}
+
+	@OutputDirectory
+	DirectoryProperty getOutputDirectory() {
+		return this.outputDirectory;
+	}
+
+	@TaskAction
+	void syncSourceJarFiles() {
+		sync(getSourceJarFiles());
+	}
+
+	private List<File> getSourceJarFiles() {
+		List<File> sourceJarFiles = new ArrayList<>();
+		for (Configuration configuration : this.configurations) {
+			ResolutionResult resolutionResult = configuration.getIncoming().getResolutionResult();
+			resolutionResult.getRootComponent().get().getDependencies().forEach(dependency -> {
+				Set<ComponentArtifactsResult> artifactsResults = resolveSourceArtifacts(dependency);
+				for (ComponentArtifactsResult artifactResult : artifactsResults) {
+					artifactResult.getArtifacts(SourcesArtifact.class).forEach(sourceArtifact -> {
+						sourceJarFiles.add(((ResolvedArtifactResult) sourceArtifact).getFile());
+					});
+				}
+			});
+		}
+		return Collections.unmodifiableList(sourceJarFiles);
+	}
+
+	private Set<ComponentArtifactsResult> resolveSourceArtifacts(DependencyResult dependency) {
+		ModuleComponentSelector componentSelector = (ModuleComponentSelector) dependency.getRequested();
+		ArtifactResolutionQuery query = getProject().getDependencies().createArtifactResolutionQuery()
+				.forModule(componentSelector.getGroup(), componentSelector.getModule(), componentSelector.getVersion());
+		return executeQuery(query).getResolvedComponents();
+	}
+
+	@SuppressWarnings("unchecked")
+	private ArtifactResolutionResult executeQuery(ArtifactResolutionQuery query) {
+		return query.withArtifacts(JvmLibrary.class, SourcesArtifact.class).execute();
+	}
+
+	private void sync(List<File> sourceJarFiles) {
+		getProject().sync(spec -> {
+			spec.into(this.outputDirectory);
+			spec.eachFile(this::relocateFile);
+			spec.filter(this::transformContent);
+			spec.exclude("META-INF/**");
+			spec.setIncludeEmptyDirs(false);
+			sourceJarFiles.forEach(sourceJar -> spec.from(zipTree(sourceJar)));
+		});
+	}
+
+	private void relocateFile(FileCopyDetails details) {
+		String path = details.getPath();
+		for (Relocation relocation : this.relocations) {
+			path = relocation.relocatePath(path);
+		}
+		details.setPath(path);
+	}
+
+	private String transformContent(String content) {
+		for (Relocation relocation : this.relocations) {
+			content = relocation.transformContent(content);
+		}
+		return content;
+	}
+
+	private FileTree zipTree(File sourceJar) {
+		return getProject().zipTree(sourceJar);
+	}
+
+
+	/**
+	 * A single relocation.
+	 */
+	static class Relocation {
+
+		private final String pattern;
+
+		private final String pathPattern;
+
+		private final String destination;
+
+		private final String pathDestination;
+
+
+		Relocation(String pattern, String destination) {
+			this.pattern = pattern;
+			this.pathPattern = pattern.replace('.', '/');
+			this.destination = destination;
+			this.pathDestination = destination.replace('.', '/');
+		}
+
+
+		@Input
+		public String getPattern() {
+			return this.pattern;
+		}
+
+		@Input
+		public String getDestination() {
+			return this.destination;
+		}
+
+		String relocatePath(String path) {
+			return path.replace(this.pathPattern, this.pathDestination);
+		}
+
+		public String transformContent(String content) {
+			return content.replaceAll("\\b" + this.pattern, this.destination);
+		}
+
+	}
+
+}

spring-core/spring-core.gradle

@@ -1,4 +1,5 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+import org.springframework.build.shadow.ShadowSource
 
 description = "Spring Core"
 
@@ -27,6 +28,13 @@ task cglibRepackJar(type: ShadowJar) {
 	relocate 'org.objectweb.asm', 'org.springframework.asm'
 }
 
+task cglibSource(type: ShadowSource) {
+	configurations = [project.configurations.cglib]
+	relocate 'net.sf.cglib', 'org.springframework.cglib'
+	relocate 'org.objectweb.asm', 'org.springframework.asm'
+	outputDirectory = file("build/shadow-source/cglib")
+}
+
 task javapoetRepackJar(type: ShadowJar) {
 	archiveBaseName.set('spring-javapoet-repack')
 	archiveVersion.set(javapoetVersion)
@@ -34,6 +42,12 @@ task javapoetRepackJar(type: ShadowJar) {
 	relocate 'com.squareup.javapoet', 'org.springframework.javapoet'
 }
 
+task javapoetSource(type: ShadowSource) {
+	configurations = [project.configurations.javapoet]
+	relocate 'com.squareup.javapoet', 'org.springframework.javapoet'
+	outputDirectory = file("build/shadow-source/javapoet")
+}
+
 task objenesisRepackJar(type: ShadowJar) {
 	archiveBaseName.set('spring-objenesis-repack')
 	archiveVersion.set(objenesisVersion)
@@ -41,6 +55,12 @@ task objenesisRepackJar(type: ShadowJar) {
 	relocate 'org.objenesis', 'org.springframework.objenesis'
 }
 
+task objenesisSource(type: ShadowSource) {
+	configurations = [project.configurations.objenesis]
+	relocate 'org.objenesis', 'org.springframework.objenesis'
+	outputDirectory = file("build/shadow-source/objenesis")
+}
+
 dependencies {
 	cglib("cglib:cglib:${cglibVersion}@jar")
 	javapoet("com.squareup:javapoet:${javapoetVersion}@jar")
@@ -122,3 +142,9 @@ test {
 		"-XX:+AllowRedefinitionToAddDeleteMethods"
 	]
 }
+
+sourcesJar {
+	from cglibSource
+	from javapoetSource
+	from objenesisSource
+}