Revert "SONAR-10541, SONAR-10331 Drop compatibility mode and clean plugin classloader"

This reverts commit 4dcb5245f1147048d122ff2d335a6b5b7364c565.

7 files changed, 126 insertions, 32 deletions

diff --git a/sonar-core/build.gradle b/sonar-core/build.gradle
index aad84e6dbfe..a2d0f1bb189 100644
--- a/sonar-core/build.gradle
+++ b/sonar-core/build.gradle
@@ -4,6 +4,10 @@ sonarqube {
   }
 }
 
+configurations {
+  includeInResources
+}
+
 dependencies {
   // please keep list ordered
 
@@ -20,6 +24,8 @@ dependencies {
 
   compileOnly 'com.google.code.findbugs:jsr305'
 
+  includeInResources project(path: ':sonar-plugin-api-deps', configuration: 'shadow')
+
   testCompile 'com.tngtech.java:junit-dataprovider'
   testCompile 'junit:junit'
   testCompile 'org.assertj:assertj-core'
@@ -30,6 +36,14 @@ dependencies {
   testCompileOnly 'com.google.code.findbugs:jsr305'
 }
 
+// sonar-plugin-api.jar is copied into target JAR file
+processResources {
+  into('/') {
+    from configurations.includeInResources
+    rename '(.*)-' + project.version + '-all.jar', '$1.jar'
+  }
+}
+
 // Used by sonar-db-core to run DB Unit Tests
 artifactoryPublish.skip = false
 publishing {
diff --git a/sonar-core/src/main/java/org/sonar/core/platform/PluginClassLoaderDef.java b/sonar-core/src/main/java/org/sonar/core/platform/PluginClassLoaderDef.java
index d228ee088bd..c1c3584b58a 100644
--- a/sonar-core/src/main/java/org/sonar/core/platform/PluginClassLoaderDef.java
+++ b/sonar-core/src/main/java/org/sonar/core/platform/PluginClassLoaderDef.java
@@ -41,6 +41,11 @@ class PluginClassLoaderDef {
   private final Mask mask = new Mask();
   private boolean selfFirstStrategy = false;
 
+  /**
+   * Compatibility with API classloader as defined before version 5.2
+   */
+  private boolean compatibilityMode = false;
+
   PluginClassLoaderDef(String basePluginKey) {
     Preconditions.checkArgument(!Strings.isNullOrEmpty(basePluginKey));
     this.basePluginKey = basePluginKey;
@@ -80,6 +85,14 @@ class PluginClassLoaderDef {
     }
   }
 
+  boolean isCompatibilityMode() {
+    return compatibilityMode;
+  }
+
+  void setCompatibilityMode(boolean b) {
+    this.compatibilityMode = b;
+  }
+
   @Override
   public boolean equals(@Nullable Object o) {
     if (this == o) {
diff --git a/sonar-core/src/main/java/org/sonar/core/platform/PluginClassloaderFactory.java b/sonar-core/src/main/java/org/sonar/core/platform/PluginClassloaderFactory.java
index bc584778d68..0c69f978a09 100644
--- a/sonar-core/src/main/java/org/sonar/core/platform/PluginClassloaderFactory.java
+++ b/sonar-core/src/main/java/org/sonar/core/platform/PluginClassloaderFactory.java
@@ -25,9 +25,11 @@ import java.net.URL;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import org.apache.commons.io.FileUtils;
 import org.sonar.api.batch.ScannerSide;
 import org.sonar.api.ce.ComputeEngineSide;
 import org.sonar.api.server.ServerSide;
+import org.sonar.api.utils.TempFolder;
 import org.sonar.classloader.ClassloaderBuilder;
 import org.sonar.classloader.Mask;
 
@@ -38,6 +40,8 @@ import static org.sonar.classloader.ClassloaderBuilder.LoadingOrder.SELF_FIRST;
  * Builds the graph of classloaders to be used to instantiate plugins. It deals with:
  * <ul>
  *   <li>isolation of plugins against core classes (except api)</li>
+ *   <li>backward-compatibility with plugins built for versions of SQ lower than 5.2. At that time
+ *   API declared transitive dependencies that were automatically available to plugins</li>
  *   <li>sharing of some packages between plugins</li>
  *   <li>loading of the libraries embedded in plugin JAR files (directory META-INF/libs)</li>
  * </ul>
@@ -50,6 +54,13 @@ public class PluginClassloaderFactory {
   // underscores are used to not conflict with plugin keys (if someday a plugin key is "api")
   private static final String API_CLASSLOADER_KEY = "_api_";
 
+  private final TempFolder temp;
+  private URL compatibilityModeJar;
+
+  public PluginClassloaderFactory(TempFolder temp) {
+    this.temp = temp;
+  }
+
   /**
    * Creates as many classloaders as requested by the input parameter.
    */
@@ -67,6 +78,9 @@ public class PluginClassloaderFactory {
       for (File jar : def.getFiles()) {
         builder.addURL(def.getBasePluginKey(), fileToUrl(jar));
       }
+      if (def.isCompatibilityMode()) {
+        builder.addURL(def.getBasePluginKey(), extractCompatibilityModeJar());
+      }
       exportResources(def, builder, defs);
     }
 
@@ -106,6 +120,19 @@ public class PluginClassloaderFactory {
     return getClass().getClassLoader();
   }
 
+  private URL extractCompatibilityModeJar() {
+    if (compatibilityModeJar == null) {
+      File jar = temp.newFile("sonar-plugin-api-deps", "jar");
+      try {
+        FileUtils.copyURLToFile(getClass().getResource("/sonar-plugin-api-deps.jar"), jar);
+        compatibilityModeJar = jar.toURI().toURL();
+      } catch (Exception e) {
+        throw new IllegalStateException("Can not extract sonar-plugin-api-deps.jar to " + jar.getAbsolutePath(), e);
+      }
+    }
+    return compatibilityModeJar;
+  }
+
   private static URL fileToUrl(File file) {
     try {
       return file.toURI().toURL();
@@ -122,25 +149,31 @@ public class PluginClassloaderFactory {
    */
   private static Mask apiMask() {
     return new Mask()
-      .addInclusion("org/sonar/api/")
+        .addInclusion("org/sonar/api/")
+      .addInclusion("org/sonar/channel/")
       .addInclusion("org/sonar/check/")
+      .addInclusion("org/sonar/colorizer/")
+      .addInclusion("org/sonar/duplications/")
+      .addInclusion("org/sonar/graph/")
+      .addInclusion("org/sonar/plugins/emailnotifications/api/")
+      .addInclusion("net/sourceforge/pmd/")
+      .addInclusion("org/apache/maven/")
       .addInclusion("org/codehaus/stax2/")
       .addInclusion("org/codehaus/staxmate/")
       .addInclusion("com/ctc/wstx/")
       .addInclusion("org/slf4j/")
+      .addInclusion("javax/servlet/")
 
       // SLF4J bridges. Do not let plugins re-initialize and configure their logging system
       .addInclusion("org/apache/commons/logging/")
       .addInclusion("org/apache/log4j/")
       .addInclusion("ch/qos/logback/")
 
-      // Exposed by org.sonar.api.server.authentication.IdentityProvider
-      .addInclusion("javax/servlet/")
-
-      // required for some internal SonarSource plugins (billing, orchestrator, ...)
+      // required for internal libs at SonarSource
       .addInclusion("org/sonar/server/platform/")
-
-      // required for commercial plugins at SonarSource
+      .addInclusion("org/sonar/core/persistence/")
+      .addInclusion("org/sonar/core/properties/")
+      .addInclusion("org/sonar/server/views/")
       .addInclusion("com/sonarsource/plugins/license/api/")
 
       // API exclusions
diff --git a/sonar-core/src/main/java/org/sonar/core/platform/PluginLoader.java b/sonar-core/src/main/java/org/sonar/core/platform/PluginLoader.java
index 7b045fe6961..f44a346336e 100644
--- a/sonar-core/src/main/java/org/sonar/core/platform/PluginLoader.java
+++ b/sonar-core/src/main/java/org/sonar/core/platform/PluginLoader.java
@@ -50,7 +50,7 @@ public class PluginLoader {
 
   private static final String[] DEFAULT_SHARED_RESOURCES = {"org/sonar/plugins", "com/sonar/plugins", "com/sonarsource/plugins"};
 
-  private static final Version COMPATIBILITY_MODE_MAX_VERSION = Version.create("5.2");
+  public static final Version COMPATIBILITY_MODE_MAX_VERSION = Version.create("5.2");
 
   private final PluginJarExploder jarExploder;
   private final PluginClassloaderFactory classloaderFactory;
@@ -96,14 +96,15 @@ public class PluginLoader {
         def.setSelfFirstStrategy(info.isUseChildFirstClassLoader());
         Version minSqVersion = info.getMinimalSqVersion();
         boolean compatibilityMode = minSqVersion != null && minSqVersion.compareToIgnoreQualifier(COMPATIBILITY_MODE_MAX_VERSION) < 0;
+        def.setCompatibilityMode(compatibilityMode);
         if (compatibilityMode) {
-          Loggers.get(getClass()).warn("API compatibility mode is no longer supported. In case of error, plugin {} [{}] should package its dependencies.",
-            info.getName(), info.getKey());
+          Loggers.get(getClass()).debug("API compatibility mode is enabled on plugin {} [{}] " +
+            "(built with API lower than {})",
+            info.getName(), info.getKey(), COMPATIBILITY_MODE_MAX_VERSION);
         }
       }
     }
     return classloadersByBasePlugin.values();
-
   }
 
   /**
diff --git a/sonar-core/src/main/java/org/sonar/core/util/FileUtils.java b/sonar-core/src/main/java/org/sonar/core/util/FileUtils.java
index 079fa552539..5b91a8055f3 100644
--- a/sonar-core/src/main/java/org/sonar/core/util/FileUtils.java
+++ b/sonar-core/src/main/java/org/sonar/core/util/FileUtils.java
@@ -114,7 +114,7 @@ public final class FileUtils {
    * <li>No exceptions are thrown when a file or directory cannot be deleted.</li>
    * </ul>
    *
-   * @param path file or directory to delete, can be {@code null}
+   * @param file  file or directory to delete, can be {@code null}
    * @return {@code true} if the file or directory was deleted, otherwise {@code false}
    */
   public static boolean deleteQuietly(@Nullable Path path) {
diff --git a/sonar-core/src/test/java/org/sonar/core/platform/PluginClassloaderFactoryTest.java b/sonar-core/src/test/java/org/sonar/core/platform/PluginClassloaderFactoryTest.java
index 329a5431d7a..9d825b758af 100644
--- a/sonar-core/src/test/java/org/sonar/core/platform/PluginClassloaderFactoryTest.java
+++ b/sonar-core/src/test/java/org/sonar/core/platform/PluginClassloaderFactoryTest.java
@@ -23,8 +23,10 @@ import com.sonarsource.plugins.license.api.FooBar;
 import java.io.File;
 import java.util.Map;
 import org.apache.commons.lang.StringUtils;
+import org.junit.Rule;
 import org.junit.Test;
 import org.sonar.api.server.rule.RulesDefinition;
+import org.sonar.api.utils.internal.JUnitTempFolder;
 
 import static java.util.Arrays.asList;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -36,7 +38,10 @@ public class PluginClassloaderFactoryTest {
   static final String BASE_PLUGIN_KEY = "base";
   static final String DEPENDENT_PLUGIN_KEY = "dependent";
 
-  PluginClassloaderFactory factory = new PluginClassloaderFactory();
+  @Rule
+  public JUnitTempFolder temp = new JUnitTempFolder();
+
+  PluginClassloaderFactory factory = new PluginClassloaderFactory(temp);
 
   @Test
   public void create_isolated_classloader() {
@@ -57,6 +62,20 @@ public class PluginClassloaderFactoryTest {
   }
 
   @Test
+  public void create_classloader_compatible_with_with_old_api_dependencies() {
+    PluginClassLoaderDef def = basePluginDef();
+    def.setCompatibilityMode(true);
+    ClassLoader classLoader = factory.create(asList(def)).get(def);
+
+    // Plugin can access to API and its transitive dependencies as defined in version 5.1.
+    // It can not access to core classes though, even if it was possible in previous versions.
+    assertThat(canLoadClass(classLoader, RulesDefinition.class.getCanonicalName())).isTrue();
+    assertThat(canLoadClass(classLoader, StringUtils.class.getCanonicalName())).isTrue();
+    assertThat(canLoadClass(classLoader, BASE_PLUGIN_CLASSNAME)).isTrue();
+    assertThat(canLoadClass(classLoader, PluginClassloaderFactory.class.getCanonicalName())).isFalse();
+  }
+
+  @Test
   public void classloader_exports_resources_to_other_classloaders() {
     PluginClassLoaderDef baseDef = basePluginDef();
     PluginClassLoaderDef dependentDef = dependentPluginDef();
diff --git a/sonar-core/src/test/java/org/sonar/core/platform/PluginLoaderTest.java b/sonar-core/src/test/java/org/sonar/core/platform/PluginLoaderTest.java
index 2a2ae2c3575..76a1268f933 100644
--- a/sonar-core/src/test/java/org/sonar/core/platform/PluginLoaderTest.java
+++ b/sonar-core/src/test/java/org/sonar/core/platform/PluginLoaderTest.java
@@ -21,15 +21,13 @@ package org.sonar.core.platform;
 
 import com.google.common.collect.ImmutableMap;
 import java.io.File;
+import java.io.IOException;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import org.assertj.core.data.MapEntry;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
-import org.sonar.api.utils.log.LogTester;
-import org.sonar.api.utils.log.LoggerLevel;
 import org.sonar.updatecenter.common.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -41,11 +39,8 @@ public class PluginLoaderTest {
   @Rule
   public TemporaryFolder temp = new TemporaryFolder();
 
-  @Rule
-  public LogTester logTester = new LogTester();
-
   private PluginClassloaderFactory classloaderFactory = mock(PluginClassloaderFactory.class);
-  private PluginLoader underTest = new PluginLoader(new FakePluginExploder(), classloaderFactory);
+  private PluginLoader loader = new PluginLoader(new FakePluginExploder(), classloaderFactory);
 
   @Test
   public void define_classloader() throws Exception {
@@ -55,7 +50,7 @@ public class PluginLoaderTest {
       .setMainClass("org.foo.FooPlugin")
       .setMinimalSqVersion(Version.create("5.2"));
 
-    Collection<PluginClassLoaderDef> defs = underTest.defineClassloaders(ImmutableMap.of("foo", info));
+    Collection<PluginClassLoaderDef> defs = loader.defineClassloaders(ImmutableMap.of("foo", info));
 
     assertThat(defs).hasSize(1);
     PluginClassLoaderDef def = defs.iterator().next();
@@ -64,6 +59,21 @@ public class PluginLoaderTest {
     assertThat(def.getFiles()).containsOnly(jarFile);
     assertThat(def.getMainClassesByPluginKey()).containsOnly(MapEntry.entry("foo", "org.foo.FooPlugin"));
     // TODO test mask - require change in sonar-classloader
+
+    // built with SQ 5.2+ -> does not need API compatibility mode
+    assertThat(def.isCompatibilityMode()).isFalse();
+  }
+
+  @Test
+  public void enable_compatibility_mode_if_plugin_is_built_before_5_2() throws Exception {
+    File jarFile = temp.newFile();
+    PluginInfo info = new PluginInfo("foo")
+      .setJarFile(jarFile)
+      .setMainClass("org.foo.FooPlugin")
+      .setMinimalSqVersion(Version.create("4.5.2"));
+
+    Collection<PluginClassLoaderDef> defs = loader.defineClassloaders(ImmutableMap.of("foo", info));
+    assertThat(defs.iterator().next().isCompatibilityMode()).isTrue();
   }
 
   /**
@@ -94,7 +104,7 @@ public class PluginLoaderTest {
       .setBasePlugin("foo")
       .setUseChildFirstClassLoader(true);
 
-    Collection<PluginClassLoaderDef> defs = underTest.defineClassloaders(ImmutableMap.of(
+    Collection<PluginClassLoaderDef> defs = loader.defineClassloaders(ImmutableMap.of(
       base.getKey(), base, extension1.getKey(), extension1, extension2.getKey(), extension2));
 
     assertThat(defs).hasSize(1);
@@ -110,18 +120,22 @@ public class PluginLoaderTest {
   }
 
   @Test
-  public void log_warning_if_plugin_is_built_with_api_5_2_or_lower() throws Exception {
-    File jarFile = temp.newFile();
-    PluginInfo info = new PluginInfo("foo")
-      .setJarFile(jarFile)
-      .setMainClass("org.foo.FooPlugin")
-      .setMinimalSqVersion(Version.create("4.5.2"));
+  public void plugin_is_not_recognised_as_system_extension_if_key_is_governance_and_extends_another_plugin() throws IOException {
+    PluginInfo foo = createPluginInfo("foo");
+    PluginInfo governance = createPluginInfo("governance")
+      .setBasePlugin("foo");
+
+    Collection<PluginClassLoaderDef> defs = loader.defineClassloaders(ImmutableMap.of("foo", foo, "governance", governance));
 
-    Collection<PluginClassLoaderDef> defs = underTest.defineClassloaders(ImmutableMap.of("foo", info));
-    assertThat(defs).extracting(PluginClassLoaderDef::getBasePluginKey).containsExactly("foo");
+    assertThat(defs).extracting("compatibilityMode").containsOnly(false, false);
+  }
 
-    List<String> warnings = logTester.logs(LoggerLevel.WARN);
-    assertThat(warnings).contains("API compatibility mode is no longer supported. In case of error, plugin foo [foo] should package its dependencies.");
+  private PluginInfo createPluginInfo(String pluginKey) throws IOException {
+    File jarFile = temp.newFile();
+    return new PluginInfo(pluginKey)
+      .setJarFile(jarFile)
+      .setMainClass("org.foo." + pluginKey + "Plugin")
+      .setMinimalSqVersion(Version.create("6.6"));
   }
 
   /**