Maven: Make compiler plugin option reporting more user-friendly

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinCompileMojoBase.java

@@ -328,10 +328,13 @@ public abstract class KotlinCompileMojoBase<A extends CommonCompilerArguments> e
             String pluginName = pluginEntry.getKey();
             KotlinMavenPluginExtension plugin = pluginEntry.getValue();
 
+            // applied plugin (...) to info()
             if (plugin.isApplicable(project, mojoExecution)) {
+                getLog().info("Applied plugin: '" + pluginName + "'");
                 List<PluginOption> optionsForPlugin = plugin.getPluginOptions(project, mojoExecution);
-                getLog().info("Options for plugin " + pluginName + ": " + optionsForPlugin);
-                pluginOptions.addAll(optionsForPlugin);
+                if (!optionsForPlugin.isEmpty()) {
+                    pluginOptions.addAll(optionsForPlugin);
+                }
             }
         }
 
@@ -339,6 +342,34 @@ public abstract class KotlinCompileMojoBase<A extends CommonCompilerArguments> e
             pluginOptions.addAll(parseUserProvidedPluginOptions(this.pluginOptions, plugins));
         }
 
+        Map<String, List<PluginOption>> optionsByPluginName = new LinkedHashMap<String, List<PluginOption>>();
+        for (PluginOption option : pluginOptions) {
+            List<PluginOption> optionsForPlugin = optionsByPluginName.get(option.pluginName);
+            if (optionsForPlugin == null) {
+                optionsForPlugin = new ArrayList<PluginOption>();
+                optionsByPluginName.put(option.pluginName, optionsForPlugin);
+            }
+
+            optionsForPlugin.add(option);
+        }
+
+        for (Map.Entry<String, List<PluginOption>> entry : optionsByPluginName.entrySet()) {
+            assert !entry.getValue().isEmpty();
+
+            String pluginName = entry.getValue().get(0).pluginName;
+
+            StringBuilder renderedOptions = new StringBuilder("[");
+            for (PluginOption option : entry.getValue()) {
+                if (renderedOptions.length() > 1) {
+                    renderedOptions.append(", ");
+                }
+                renderedOptions.append(option.key).append(": ").append(option.value);
+            }
+            renderedOptions.append("]");
+
+            getLog().debug("Options for plugin " + pluginName + ": " + renderedOptions);
+        }
+
         return pluginOptions;
     }
 
@@ -363,7 +394,7 @@ public abstract class KotlinCompileMojoBase<A extends CommonCompilerArguments> e
                 throw new PluginNotFoundException(pluginName);
             }
 
-            pluginOptions.add(new PluginOption(plugin.getCompilerPluginId(), key, value));
+            pluginOptions.add(new PluginOption(pluginName, plugin.getCompilerPluginId(), key, value));
         }
 
         return pluginOptions;

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/PluginOption.java

@@ -1,11 +1,17 @@
 package org.jetbrains.kotlin.maven;
 
 public class PluginOption {
+    /** The plugin name in Maven, e.g. "all-open" */
+    public final String pluginName;
+
+    /** The compiler plugin identifier, e.g. "org.jetbrains.kotlin.allopen" */
     public final String pluginId;
+
     public final String key;
     public final String value;
 
-    public PluginOption(String pluginId, String key, String value) {
+    public PluginOption(String pluginName, String pluginId, String key, String value) {
+        this.pluginName = pluginName;
         this.pluginId = pluginId;
         this.key = key;
         this.value = value;