Experimental support for layered images

This commit introduces a Gradle DSL to support layered images creation.
As of now, this is mainly aimed towards a single use case which is incremental builds.
The test project demonstrates how to use the DSL to create a base layer which includes
the JDK "java.base" module as well as all external dependencies used by the project.

The DSL builds on top of the binaries concept, by allowing them to declare either
that they produce a layer, or that they use one or more layers. The DSL contains
methods to make it easier to declare use or creation, as well as supports an easy
way to declare that a layer should use only external dependencies. For example,
this is how you would create a base layer and consume it from the main binary:

```
graalvmNative {
    binaries {
        libdependencies {
            createLayer {
                modules = ["java.base"]
                jars.from(externalDependenciesOf(configurations.runtimeClasspath))
            }
        }
        main {
            useLayer("libdependencies")
        }
    }
}
```

Note that there is a _binary_ named `libdependencies`, and as soon
as the `createLayer` is called, it will offer additional options which are
specific to layers (for example declaring the list of packages or modules).

The DSL to create a layer contains the `packages` option, which could be
used with automatic extraction of package names, which is why there is
code to extract packages from jars, however, this code is currently
unused for a reason: these packages can contain dependencies to "optional"
modules, which cannot be figured out at build time. Typically, logback
will support additional modules and load them dynamically, and if the
package is included in the list and that the supporting dependencies
are not on classpath, then the layer creation would fail. Therefore,
the only reliable option right now is to use the `jars` property to
set the list of jars which should belong to the layer.

Author: melix

build-logic/common-plugins/src/main/kotlin/org.graalvm.build.java.gradle.kts

@@ -64,12 +64,16 @@ repositories {
 group = "org.graalvm.buildtools"
 
 extensions.findByType<VersionCatalogsExtension>()?.also { catalogs ->
-    val versionFromCatalog = catalogs.named("libs")
+    if (catalogs.find("libs").isPresent) {
+        val versionFromCatalog = catalogs.named("libs")
             .findVersion("nativeBuildTools")
-    if (versionFromCatalog.isPresent()) {
-        version = versionFromCatalog.get().requiredVersion
+        if (versionFromCatalog.isPresent()) {
+            version = versionFromCatalog.get().requiredVersion
+        } else {
+            throw GradleException("Version catalog doesn't define project version 'nativeBuildTools'")
+        }
     } else {
-        throw GradleException("Version catalog doesn't define project version 'nativeBuildTools'")
+        version = "undefined"
     }
 }
 

common/utils/src/main/java/org/graalvm/buildtools/utils/JarMetadata.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2003-2021 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.graalvm.buildtools.utils;
+
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Properties;
+
+public class JarMetadata {
+    private final List<String> packageList;
+
+    public JarMetadata(List<String> packageList) {
+        this.packageList = packageList;
+    }
+
+    public List<String> getPackageList() {
+        return packageList;
+    }
+
+    public static JarMetadata readFrom(Path propertiesFile) {
+        Properties props = new Properties();
+        try (InputStream is = Files.newInputStream(propertiesFile)) {
+            props.load(is);
+        } catch (Exception e) {
+            throw new RuntimeException("Unable to read metadata from properties file " + propertiesFile, e);
+        }
+        String packages = (String) props.get("packages");
+        List<String> packageList = packages == null ? List.of() : Arrays.asList(packages.split(","));
+        return new JarMetadata(packageList);
+    }
+}

common/utils/src/main/java/org/graalvm/buildtools/utils/JarScanner.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2003-2021 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.graalvm.buildtools.utils;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.Writer;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.stream.Stream;
+
+/**
+ * Performs scanning of a JAR file and extracts some metadata in the
+ * form of a properties file. For now this type only extracts the list
+ * of packages from a jar.
+ */
+public class JarScanner {
+    /**
+     * Scans a jar and creates a properties file with metadata about the jar contents.
+     * @param inputJar the input jar
+     * @param outputFile the output file
+     * @throws IOException
+     */
+    public static void scanJar(Path inputJar, Path outputFile) throws IOException {
+        try (Writer fileWriter = Files.newBufferedWriter(outputFile); PrintWriter writer = new PrintWriter(fileWriter)) {
+            Set<String> packageList = new TreeSet<>();
+            try (FileSystem jarFileSystem = FileSystems.newFileSystem(inputJar, null)) {
+                Path root = jarFileSystem.getPath("/");
+                try (Stream<Path> files = Files.walk(root)) {
+                    files.forEach(path -> {
+                        if (path.toString().endsWith(".class") && !path.toString().contains("META-INF")) {
+                            Path relativePath = root.relativize(path);
+                            String className = relativePath.toString()
+                                .replace('/', '.')
+                                .replace('\\', '.')
+                                .replaceAll("[.]class$", "");
+                            var lastDot = className.lastIndexOf(".");
+                            if (lastDot > 0) {
+                                var packageName = className.substring(0, lastDot);
+                                packageList.add(packageName);
+                            }
+                        }
+                    });
+                }
+            }
+            writer.println("packages=" + String.join(",", packageList));
+        } catch (IOException ex) {
+            throw new RuntimeException("Unable to write JAR analysis", ex);
+        }
+    }
+}

docs/src/docs/asciidoc/changelog.adoc

@@ -1,6 +1,12 @@
 [[changelog]]
 == Changelog
 
+== Release 0.10.7
+
+=== Gradle plugin
+
+- Added experimental support for layered images
+
 == Release 0.10.6
 
 === Gradle plugin

native-gradle-plugin/src/functionalTest/groovy/org/graalvm/buildtools/gradle/LayeredApplicationFunctionalTest.groovy

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * The Universal Permissive License (UPL), Version 1.0
+ *
+ * Subject to the condition set forth below, permission is hereby granted to any
+ * person obtaining a copy of this software, associated documentation and/or
+ * data (collectively the "Software"), free of charge and under any and all
+ * copyright rights in the Software, and any and all patent rights owned or
+ * freely licensable by each licensor hereunder covering either (i) the
+ * unmodified Software as contributed to or provided by such licensor, or (ii)
+ * the Larger Works (as defined below), to deal in both
+ *
+ * (a) the Software, and
+ *
+ * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+ * one is included with the Software each a "Larger Work" to which the Software
+ * is contributed by such licensors),
+ *
+ * without restriction, including without limitation the rights to copy, create
+ * derivative works of, display, perform, and distribute the Software and make,
+ * use, sell, offer for sale, import, export, have made, and have sold the
+ * Software and the Larger Work(s), and to sublicense the foregoing rights on
+ * either these or other terms.
+ *
+ * This license is subject to the following condition:
+ *
+ * The above copyright notice and either this complete permission notice or at a
+ * minimum a reference to the UPL must be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.graalvm.buildtools.gradle
+
+import org.graalvm.buildtools.gradle.fixtures.AbstractFunctionalTest
+import org.graalvm.buildtools.gradle.fixtures.GraalVMSupport
+import org.graalvm.buildtools.utils.NativeImageUtils
+import spock.lang.Requires
+
+@Requires(
+        { NativeImageUtils.getMajorJDKVersion(GraalVMSupport.getGraalVMHomeVersionString()) >= 25 }
+)
+class LayeredApplicationFunctionalTest extends AbstractFunctionalTest {
+    def "can build a native image using layers"() {
+        def nativeApp = getExecutableFile("build/native/nativeCompile/layered-java-application")
+
+        given:
+        withSample("layered-java-application")
+
+        when:
+        run 'nativeLibdependenciesCompile'
+
+        then:
+        tasks {
+            succeeded ':nativeLibdependenciesCompile'
+        }
+        outputContains "'-H:LayerCreate' (origin(s): command line)"
+
+        when:
+        run 'nativeRun', '-Pmessage="Hello, layered images!"'
+
+        then:
+        tasks {
+            upToDate ':nativeLibdependenciesCompile'
+            succeeded ':nativeCompile'
+        }
+        nativeApp.exists()
+
+        and:
+        outputContains "- '-H:LayerUse' (origin(s): command line)"
+        outputContains "Hello, layered images!"
+
+        when: "Updating the application without changing the dependencies"
+        file("src/main/java/org/graalvm/demo/Application.java").text = """
+package org.graalvm.demo;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class Application {
+    private static final Logger LOGGER = LoggerFactory.getLogger(Application.class);
+
+    public static void main(String[] args) {
+        LOGGER.info("App started with args {}", String.join(", ", args));
+    }
+
+}
+
+"""
+        run 'nativeRun', '-Pmessage="Hello, layered images!"'
+
+        then:
+        tasks {
+            // Base layer is not rebuilt
+            upToDate ':nativeLibdependenciesCompile'
+            // Application layer is recompiled
+            succeeded ':nativeCompile'
+        }
+
+        outputContains "- '-H:LayerUse' (origin(s): command line)"
+        outputContains "Hello, layered images!"
+    }
+}