[java] extracts module virtual file detection routine

java/java-impl/src/com/intellij/lang/java/JavaDocumentationProvider.java

@@ -44,8 +44,8 @@ import com.intellij.openapi.vfs.JarFileSystem;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.VirtualFileSystem;
 import com.intellij.psi.*;
+import com.intellij.psi.impl.PsiImplUtil;
 import com.intellij.psi.impl.beanProperties.BeanPropertyElement;
-import com.intellij.psi.impl.light.LightJavaModule;
 import com.intellij.psi.impl.source.javadoc.PsiDocParamRef;
 import com.intellij.psi.infos.CandidateInfo;
 import com.intellij.psi.javadoc.PsiDocComment;
@@ -381,16 +381,7 @@ public class JavaDocumentationProvider extends DocumentationProviderEx implement
   private static String generateModuleInfo(PsiJavaModule module) {
     StringBuilder sb = new StringBuilder();
 
-    VirtualFile file = null;
-    if (module instanceof LightJavaModule) {
-      PsiElement target = module.getNavigationElement();
-      if (target instanceof PsiDirectory) {
-        file = ((PsiDirectory)target).getVirtualFile();
-      }
-    }
-    else {
-      file = module.getContainingFile().getVirtualFile();
-    }
+    VirtualFile file = PsiImplUtil.getModuleVirtualFile(module);
     generateOrderEntryInfo(sb, file, module.getProject());
 
     sb.append(LangBundle.message("java.terms.module")).append(' ').append(module.getModuleName());

java/java-psi-impl/src/com/intellij/psi/impl/PsiImplUtil.java

@@ -25,9 +25,11 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.intellij.psi.filters.ElementFilter;
 import com.intellij.psi.impl.light.LightClassReference;
+import com.intellij.psi.impl.light.LightJavaModule;
 import com.intellij.psi.impl.source.PsiClassReferenceType;
 import com.intellij.psi.impl.source.PsiImmediateClassType;
 import com.intellij.psi.impl.source.resolve.ResolveCache;
@@ -735,4 +737,13 @@ public class PsiImplUtil {
       ResolveCache.getInstance(project).resolveWithCaching(element, resolver, true, incompleteCode, psiFile);
     return results.length == 0 ? JavaResolveResult.EMPTY_ARRAY : (JavaResolveResult[])results;
   }
-}
+
+  public static VirtualFile getModuleVirtualFile(@NotNull PsiJavaModule module) {
+    if (module instanceof LightJavaModule) {
+      return ((LightJavaModule)module).getRootVirtualFile();
+    }
+    else {
+      return module.getContainingFile().getVirtualFile();
+    }
+  }
+}

java/java-psi-impl/src/com/intellij/psi/impl/light/LightJavaModule.java

@@ -50,6 +50,11 @@ public class LightJavaModule extends LightElement implements PsiJavaModule {
     myRefElement = new LightJavaModuleReferenceElement(manager, moduleName(jarRoot.getNameWithoutExtension()));
   }
 
+  @NotNull
+  public VirtualFile getRootVirtualFile() {
+    return myJarRoot;
+  }
+
   @Nullable
   @Override
   public PsiDocComment getDocComment() {