Initial "address of a for loop variable" inspection

deadok22 · deadok22 · commit 7845df60f74b · 2016-03-30T14:41:05.000+09:00
diff --git a/resources/META-INF/plugin.xml b/resources/META-INF/plugin.xml
@@ -236,6 +236,9 @@
     <localInspection language="go" displayName="Printf/Logf placeholder handler" groupPath="Go"
                      groupName="Probable bug" enabledByDefault="true" level="WARNING"
                      implementationClass="com.goide.inspections.GoPlaceholderCountInspection"/>
+    <localInspection language="go" displayName="Obtaining address of a for loop variable" groupPath="Go"
+                     groupName="Probable bugs" enabledByDefault="true" level="WEAK WARNING"
+                     implementationClass="com.goide.inspections.GoAddressOfLoopVariableInspection"/>
     <!-- /probable bugs -->
 
     <!-- control flow issues -->
diff --git a/resources/inspectionDescriptions/GoAddressOfLoopVariable.html b/resources/inspectionDescriptions/GoAddressOfLoopVariable.html
@@ -0,0 +1,22 @@
+<!--
+  ~ Copyright 2013-2016 Sergey Ignatov, Alexander Zolotov, Florin Patan
+  ~
+  ~ 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.
+  -->
+
+<html>
+<body>
+Checks for obtaining addresses of for loop variables.
+Address of a for loop variable remains the same on all iterations of a loop, hence it's probably a bug.
+</body>
+</html>
diff --git a/src/com/goide/inspections/GoAddressOfLoopVariableInspection.java b/src/com/goide/inspections/GoAddressOfLoopVariableInspection.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-2016 Sergey Ignatov, Alexander Zolotov, Florin Patan
+ *
+ * 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.goide.inspections;
+
+import com.goide.psi.*;
+import com.intellij.codeInspection.LocalInspectionToolSession;
+import com.intellij.codeInspection.ProblemsHolder;
+import com.intellij.psi.PsiElement;
+import com.intellij.util.ObjectUtils;
+import org.jetbrains.annotations.NotNull;
+
+public class GoAddressOfLoopVariableInspection extends GoInspectionBase {
+  @NotNull
+  @Override
+  protected GoVisitor buildGoVisitor(@NotNull ProblemsHolder holder, @NotNull LocalInspectionToolSession session) {
+    return new GoVisitor() {
+      @Override
+      public void visitUnaryExpr(@NotNull GoUnaryExpr o) {
+        if (o.getBitAnd() == null) {
+          return;
+        }
+
+        //TODO improve by supporting references to fields of struct variables
+        GoReferenceExpression refExpr = ObjectUtils.tryCast(o.getExpression(), GoReferenceExpression.class);
+        if (refExpr == null || refExpr.getQualifier() != null) {
+          return;
+        }
+
+        GoVarDefinition varDefinition = ObjectUtils.tryCast(refExpr.getReference().resolve(), GoVarDefinition.class);
+        PsiElement parent = varDefinition != null ? varDefinition.getParent() : null;
+        if (!(parent instanceof GoRangeClause)) {
+          return;
+        }
+
+        holder.registerProblem(o, "Suspicious: obtaining address of a for loop variable");
+      }
+    };
+  }
+}
diff --git a/testData/highlighting/addressOfLoopVariable.go b/testData/highlighting/addressOfLoopVariable.go
@@ -0,0 +1,7 @@
+package main
+
+func main() {
+	for _, i := range []int{1, 2, 3} {
+		println(<weak_warning descr="Suspicious: obtaining address of a for loop variable">&i</weak_warning>)
+	}
+}
diff --git a/tests/com/goide/inspections/GoHighlightingTest.java b/tests/com/goide/inspections/GoHighlightingTest.java
@@ -66,7 +66,8 @@ public void setUp() throws Exception {
       GoPlaceholderCountInspection.class,
       GoEmbeddedInterfacePointerInspection.class,
       GoStructInitializationInspection.class,
-      GoMethodOnNonLocalTypeInspection.class
+      GoMethodOnNonLocalTypeInspection.class,
+      GoAddressOfLoopVariableInspection.class
     );
   }
 
@@ -350,6 +351,8 @@ public void testUnitializedStructInitialization() {
     doWeakTest();
   }
 
+  public void testAddressOfLoopVariable() { doWeakTest(); }
+
   private long doWeakTest() {return myFixture.testHighlighting(true, false, true, getTestName(true) + ".go");}
 
   public void testDoNotHighlightCommentOfMainPackage() {
