Unsafe VFS recursion inspection

java/java-impl/src/com/intellij/codeInspection/internal/UnsafeVfsRecursionInspection.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2000-2012 JetBrains s.r.o.
+ *
+ * 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
+ *
+ * http://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 com.intellij.codeInspection.internal;
+
+import com.intellij.codeInspection.ProblemsHolder;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Ref;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.*;
+import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.util.InheritanceUtil;
+import com.intellij.psi.util.PsiTreeUtil;
+import org.jetbrains.annotations.NotNull;
+
+public class UnsafeVfsRecursionInspection extends InternalInspection {
+  private static final String VIRTUAL_FILE_CLASS_NAME = VirtualFile.class.getName();
+  private static final String GET_CHILDREN_METHOD_NAME = "getChildren";
+
+  private static final String MESSAGE =
+    "VirtualFile.getChildren() is called from a recursive method. " +
+    "This may cause an endless loop on cyclic symlinks. " +
+    "Please use VfsUtilCore.visitChildrenRecursively() instead.";
+
+  @NotNull
+  @Override
+  public PsiElementVisitor buildInternalVisitor(@NotNull final ProblemsHolder holder, final boolean isOnTheFly) {
+    return new JavaElementVisitor() {
+      @Override
+      public void visitMethodCallExpression(final PsiMethodCallExpression expression) {
+        final Project project = expression.getProject();
+        final JavaPsiFacade facade = JavaPsiFacade.getInstance(project);
+
+        final PsiReferenceExpression methodRef = expression.getMethodExpression();
+        if (!GET_CHILDREN_METHOD_NAME.equals(methodRef.getReferenceName())) return;
+        final PsiElement methodElement = methodRef.resolve();
+        if (!(methodElement instanceof PsiMethod)) return;
+        final PsiMethod method = (PsiMethod)methodElement;
+        final PsiClass aClass = method.getContainingClass();
+        final PsiClass virtualFileClass = facade.findClass(VIRTUAL_FILE_CLASS_NAME, GlobalSearchScope.allScope(project));
+        if (!InheritanceUtil.isInheritorOrSelf(aClass, virtualFileClass, true)) return;
+
+        final PsiMethod containingMethod = PsiTreeUtil.getParentOfType(expression, PsiMethod.class);
+        if (containingMethod == null) return;
+        final String containingMethodName = containingMethod.getName();
+        final Ref<Boolean> result = Ref.create();
+        containingMethod.accept(new JavaRecursiveElementVisitor() {
+          @Override
+          public void visitMethodCallExpression(final PsiMethodCallExpression expression2) {
+            if (expression2 != expression &&
+                containingMethodName.equals(expression2.getMethodExpression().getReferenceName()) &&
+                expression2.resolveMethod() == containingMethod) {
+              result.set(Boolean.TRUE);
+            }
+          }
+        });
+
+        if (!result.isNull()) {
+          holder.registerProblem(expression, MESSAGE);
+        }
+      }
+    };
+  }
+}

platform/core-api/src/com/intellij/openapi/vfs/VfsUtilCore.java

@@ -192,7 +192,7 @@ public class VfsUtilCore {
     }
 
     if (visitChildren) {
-      VirtualFile[] children = file.getChildren();
+      @SuppressWarnings("UnsafeVfsRecursion") VirtualFile[] children = file.getChildren();
       for (VirtualFile child : children) {
         visitChildrenRecursively(child, visitor, visitedSymLinks);
       }

resources-en/src/inspectionDescriptions/UnsafeVfsRecursion.html

@@ -0,0 +1,8 @@
+<html>
+<body>
+This inspection detects calls of VirtualFile.getChildren() inside recursive methods.
+Such a code may cause dead loops when iterating over cyclic symlinks -
+so please use VfsUtilCore.visitChildrenRecursively() instead.
+<p><small>Internal inspection - has no effect outside of IntelliJ IDEA project.</small></p>
+</body>
+</html>

resources/src/META-INF/IdeaPlugin.xml

@@ -211,6 +211,9 @@
     <localInspection language="JAVA" shortName="GtkPreferredJComboBoxRenderer" displayName="Preferred JComboBox renderer"
                      groupName="IDEA Platform Inspections" enabledByDefault="true" level="WARNING"
                      implementationClass="com.intellij.codeInspection.internal.GtkPreferredJComboBoxRendererInspection"/>
+    <localInspection language="JAVA" shortName="UnsafeVfsRecursion" displayName="Unsafe VFS recursion"
+                     groupName="IDEA Platform Inspections" enabledByDefault="true" level="WARNING"
+                     implementationClass="com.intellij.codeInspection.internal.UnsafeVfsRecursionInspection"/>
 
     <fileTypeFactory implementation="com.intellij.openapi.fileTypes.impl.JavaFileTypeFactory"/>