method return type in not used: fix for literal expressions(IDEA-184798)

java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefJavaUtilImpl.java

@@ -56,8 +56,11 @@ public class RefJavaUtilImpl extends RefJavaUtil{
           for (PsiReference reference : expression.getReferences()) {
             PsiElement resolve = reference.resolve();
             if (resolve instanceof PsiMember) {
-              final RefElement refClass = refFrom.getRefManager().getReference(resolve);
-              refFrom.addReference(refClass, resolve, psiFrom, false, true, null);
+              final RefElement refResolved = refFrom.getRefManager().getReference(resolve);
+              refFrom.addReference(refResolved, resolve, psiFrom, false, true, null);
+              if (refResolved instanceof RefMethod) {
+                updateRefMethod(resolve, refResolved, expression, psiFrom, refFrom);
+              }
             }
           }
         }
@@ -239,6 +242,14 @@ public class RefJavaUtilImpl extends RefJavaUtil{
       }
       return;
     }
+    if (refExpression instanceof PsiLiteralExpression){ //references in literal expressions
+      PsiType returnType = psiMethod.getReturnType();
+      if (!psiMethod.isConstructor() && !PsiType.VOID.equals(returnType)) {
+        refMethod.setReturnValueUsed(true);
+        addTypeReference(psiFrom, returnType, refFrom.getRefManager());
+      }
+      return;
+    }
     PsiMethodCallExpression call = PsiTreeUtil.getParentOfType(
       refExpression,
       PsiMethodCallExpression.class

java/java-tests/testData/inspection/unusedReturnValue/fromReflection/expected.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems/>

java/java-tests/testData/inspection/unusedReturnValue/fromReflection/src/Test.java

@@ -0,0 +1,9 @@
+class Test {
+  static String foo() {
+    return "";
+  }
+
+  {
+    Test.class.getMethod("foo");
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedReturnValueTest.java

@@ -55,6 +55,10 @@ public class UnusedReturnValueTest extends InspectionTestCase {
     doTest();
   }
 
+  public void testFromReflection() {
+    doTest();
+  }
+
   public void testSimpleSetter() {
     try {
       myTool.IGNORE_BUILDER_PATTERN = true;