From 23ab8636c5d11b5d76fadd8d5be1a57ea5c5573c Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 18 Dec 2017 09:40:57 +0100
Subject: [PATCH] IDEA-182825 Unable to compile groovy with JDK 9

use platform class loader as parent also when there's no groovy-all.jar
---
 .../com/intellij/openapi/util/ClassLoaderUtil.java  | 13 ++++++++++---
 .../jps/incremental/groovy/InProcessGroovyc.java    |  4 ++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/platform/util/src/com/intellij/openapi/util/ClassLoaderUtil.java b/platform/util/src/com/intellij/openapi/util/ClassLoaderUtil.java
index 9d72f48c51b7..6762929d0707 100644
--- a/platform/util/src/com/intellij/openapi/util/ClassLoaderUtil.java
+++ b/platform/util/src/com/intellij/openapi/util/ClassLoaderUtil.java
@@ -18,6 +18,7 @@ package com.intellij.openapi.util;
 import com.intellij.util.ThrowableRunnable;
 import com.intellij.util.lang.UrlClassLoader;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class ClassLoaderUtil {
   private ClassLoaderUtil() {
@@ -69,16 +70,22 @@ public class ClassLoaderUtil {
     }
   }
 
-  public static void addPlatformLoaderParentIfOnJdk9(@NotNull UrlClassLoader.Builder builder) {
+  @Nullable
+  public static ClassLoader getPlatformLoaderParentIfOnJdk9() {
     if (SystemInfo.IS_AT_LEAST_JAVA9) {
       // on Java 8, 'tools.jar' is on a classpath; on Java 9, its classes are available via the platform loader
       try {
-        ClassLoader platformCl = (ClassLoader)ClassLoader.class.getMethod("getPlatformClassLoader").invoke(null);
-        builder.parent(platformCl);
+        //noinspection JavaReflectionMemberAccess
+        return (ClassLoader)ClassLoader.class.getMethod("getPlatformClassLoader").invoke(null);
       }
       catch (Exception e) {
         throw new RuntimeException(e);
       }
     }
+    return null;
+  }
+
+  public static void addPlatformLoaderParentIfOnJdk9(@NotNull UrlClassLoader.Builder builder) {
+    builder.parent(getPlatformLoaderParentIfOnJdk9());
   }
 }
diff --git a/plugins/groovy/jps-plugin/src/org/jetbrains/jps/incremental/groovy/InProcessGroovyc.java b/plugins/groovy/jps-plugin/src/org/jetbrains/jps/incremental/groovy/InProcessGroovyc.java
index 6d6803723807..e28b211383c7 100644
--- a/plugins/groovy/jps-plugin/src/org/jetbrains/jps/incremental/groovy/InProcessGroovyc.java
+++ b/plugins/groovy/jps-plugin/src/org/jetbrains/jps/incremental/groovy/InProcessGroovyc.java
@@ -175,11 +175,11 @@ class InProcessGroovyc implements GroovycFlavor {
   private JointCompilationClassLoader createCompilationClassLoader(Collection<String> compilationClassPath) throws Exception {
     ClassLoader parent = obtainParentLoader(compilationClassPath);
 
-    ClassLoader groovyClassLoader = null;
+    ClassLoader groovyClassLoader;
     try {
       ClassLoader auxiliary = parent != null ? parent : buildCompilationClassLoader(compilationClassPath, null).get();
       Class<?> gcl = auxiliary.loadClass("groovy.lang.GroovyClassLoader");
-      groovyClassLoader = (ClassLoader)gcl.getConstructor(ClassLoader.class).newInstance(parent);
+      groovyClassLoader = (ClassLoader)gcl.getConstructor(ClassLoader.class).newInstance(parent != null ? parent : ClassLoaderUtil.getPlatformLoaderParentIfOnJdk9());
     }
     catch (ClassNotFoundException e) {
       return null;