safe delete: check arg side effects (IDEA-162189)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/quickfix/RemoveUnusedVariableUtil.java

@@ -20,6 +20,7 @@ import com.intellij.psi.util.PsiUtil;
 import com.intellij.util.IncorrectOperationException;
 import com.siyeh.ig.psiutils.SideEffectChecker;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -31,7 +32,7 @@ public class RemoveUnusedVariableUtil {
     CANCEL
   }
 
-  public static boolean checkSideEffects(PsiExpression element, PsiVariable variableToIgnore, List<PsiElement> sideEffects) {
+  public static boolean checkSideEffects(PsiExpression element, @Nullable PsiVariable variableToIgnore, List<PsiElement> sideEffects) {
     if (sideEffects == null || element == null) return false;
     List<PsiElement> writes = new ArrayList<>();
     SideEffectChecker.checkSideEffects(element, writes);

java/java-impl/src/com/intellij/refactoring/safeDelete/JavaSafeDeleteDelegateImpl.java

@@ -15,6 +15,7 @@
  */
 package com.intellij.refactoring.safeDelete;
 
+import com.intellij.codeInsight.daemon.impl.quickfix.RemoveUnusedVariableUtil;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.javadoc.PsiDocMethodOrFieldRef;
@@ -58,11 +59,11 @@ public class JavaSafeDeleteDelegateImpl implements JavaSafeDeleteDelegate {
         final PsiExpression[] args = argList.getExpressions();
         if (index < args.length) {
           if (!parameter.isVarArgs()) {
-            usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(args[index], parameter, true));
+            usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(args[index], parameter));
           }
           else {
             for (int i = index; i < args.length; i++) {
-              usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(args[i], parameter, true));
+              usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(args[i], parameter));
             }
           }
         }

java/java-impl/src/com/intellij/refactoring/safeDelete/usageInfo/SafeDeleteReferenceJavaDeleteUsageInfo.java

@@ -15,12 +15,15 @@
  */
 package com.intellij.refactoring.safeDelete.usageInfo;
 
+import com.intellij.codeInsight.daemon.impl.quickfix.RemoveUnusedVariableUtil;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.psi.*;
 import com.intellij.refactoring.safeDelete.ImportSearcher;
 import com.intellij.refactoring.util.RefactoringUtil;
 import com.intellij.util.IncorrectOperationException;
 
+import java.util.ArrayList;
+
 /**
  * @author yole
  */
@@ -40,6 +43,10 @@ public class SafeDeleteReferenceJavaDeleteUsageInfo extends SafeDeleteReferenceS
     super(element, referencedElement, startOffset, endOffset, isNonCodeUsage, isSafeDelete);
   }
 
+  public SafeDeleteReferenceJavaDeleteUsageInfo(PsiExpression expression, PsiElement referenceElement) {
+    this(expression, referenceElement, !RemoveUnusedVariableUtil.checkSideEffects(expression, null, new ArrayList<>()));
+  }
+
   public void deleteElement() throws IncorrectOperationException {
     if (isSafeDelete()) {
       PsiElement element = getElement();

java/java-tests/testData/refactoring/safeDelete/parameterSideEffect/after/Super.java

@@ -0,0 +1,5 @@
+class Super {
+    void foo() {
+        }
+
+}

java/java-tests/testData/refactoring/safeDelete/parameterSideEffect/before/Super.java

@@ -0,0 +1,8 @@
+class Super {
+    void foo(int <caret>i) {}
+    int bar() {return 0;}
+
+    {
+        foo(bar());
+    }
+}

java/java-tests/testSrc/com/intellij/refactoring/SafeDeleteTest.java

@@ -245,6 +245,17 @@ public class SafeDeleteTest extends MultiFileTestCase {
     }
   }
 
+  public void testParameterSideEffect() throws Exception {
+    try {
+      doTest("Super");
+      fail("Side effect was ignored");
+    }
+    catch (BaseRefactoringProcessor.ConflictsInTestsException e) {
+      String message = e.getMessage();
+      assertEquals("parameter <b><code>i</code></b> has 1 usage that is not safe to delete.", message);
+    }
+  }
+
   public void testUsageInGenerated() throws Exception {
     doTest("A");
   }