Try-with-resource support: variable usage inspection

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/TryWithResourcesWarn.java

@@ -0,0 +1,51 @@
+import java.lang.Exception;
+
+class C {
+  static class MyResource implements AutoCloseable {
+    @Override public void close() { }
+  }
+
+  void m1() throws Exception {
+    MyResource r1;
+    try (r1 = new MyResource()) {
+      System.out.println(r1);
+    }
+
+    try (MyResource r2 = new MyResource()) {
+      System.out.println(r2);
+    }
+
+    MyResource r3 = new MyResource();
+    try (MyResource r = r3) {
+      System.out.println(r);
+    }
+  }
+
+  void m2() throws Exception {
+    MyResource r1 = <warning descr="Variable 'r1' initializer 'null'  is redundant">null</warning>;
+    try (r1 = new MyResource()) {
+      System.out.println(r1);
+    }
+
+    try (MyResource r2 = <warning descr="Variable 'r2' initializer 'new MyResource()'  is redundant">new MyResource()</warning>) {
+      r2 = null;  // todo: check for NPE
+      System.out.println(r2);
+    }
+
+    MyResource r3 = null;
+    System.out.println(r3);
+    try (r3 = <warning descr="The value 'new MyResource()' assigned to r3  is never used">new MyResource()</warning>) { }
+
+    try (MyResource <warning descr="Variable 'r4' is never used">r4</warning> = new MyResource()) { }
+
+    try (MyResource r5 = new MyResource()) {
+      System.out.println(r5);
+      r5 = <warning descr="The value 'new MyResource()' assigned to r5  is never used">new MyResource()</warning>;
+    }
+
+    MyResource <warning descr="Variable 'r6' is never assigned">r6</warning>;
+    try (MyResource r = <error descr="Variable 'r6' might not have been initialized">r6</error>) {
+      System.out.println(r);
+    }
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk7Test.java

@@ -4,6 +4,7 @@ import com.intellij.ExtensionPoints;
 import com.intellij.codeInsight.daemon.impl.HighlightInfo;
 import com.intellij.codeInspection.LocalInspectionTool;
 import com.intellij.codeInspection.deadCode.UnusedDeclarationInspection;
+import com.intellij.codeInspection.defUse.DefUseInspection;
 import com.intellij.codeInspection.reference.EntryPoint;
 import com.intellij.codeInspection.reference.RefElement;
 import com.intellij.codeInspection.uncheckedWarnings.UncheckedWarningLocalInspection;
@@ -31,7 +32,7 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
 
   @Override
   protected LocalInspectionTool[] configureLocalInspectionTools() {
-    return new LocalInspectionTool[]{new UnusedSymbolLocalInspection(), new UncheckedWarningLocalInspection()};
+    return new LocalInspectionTool[]{new UnusedSymbolLocalInspection(), new UncheckedWarningLocalInspection(), new DefUseInspection()};
   }
 
   public void testDuplicateAnnotations() throws Exception {
@@ -192,6 +193,10 @@ public class LightAdvHighlightingJdk7Test extends LightDaemonAnalyzerTestCase {
     doTest(false, false);
   }
 
+  public void testTryWithResourcesWarn() throws Exception {
+    doTest(true, false);
+  }
+
   public void testSafeVarargsApplicability() throws Exception {
     doTest(true, false);
   }