Data flow values for Elvis / parenthesized expressions, smart casts on them

idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/VariablesHighlightingVisitor.java

@@ -67,6 +67,27 @@ class VariablesHighlightingVisitor extends AfterAnalysisHighlightingVisitor {
         super.visitParameter(parameter);
     }
 
+    @NotNull
+    private static PsiElement getSmartCastTarget(@NotNull KtExpression expression) {
+        PsiElement target = expression;
+        if (target instanceof KtParenthesizedExpression) {
+            target = KtPsiUtil.deparenthesize((KtParenthesizedExpression) target);
+            if (target == null) {
+                target = expression;
+            }
+        }
+        if (target instanceof KtIfExpression) {
+            target = ((KtIfExpression) target).getIfKeyword();
+        }
+        else if (target instanceof KtWhenExpression) {
+            target = ((KtWhenExpression) target).getWhenKeyword();
+        }
+        else if (target instanceof KtBinaryExpression) {
+            target = ((KtBinaryExpression) target).getOperationReference();
+        }
+        return target;
+    }
+
     @Override
     public void visitExpression(@NotNull KtExpression expression) {
         KotlinType implicitSmartCast = bindingContext.get(IMPLICIT_RECEIVER_SMARTCAST, expression);
@@ -84,14 +105,8 @@ class VariablesHighlightingVisitor extends AfterAnalysisHighlightingVisitor {
 
         KotlinType smartCast = bindingContext.get(SMARTCAST, expression);
         if (smartCast != null) {
-            PsiElement target = expression;
-            if (expression instanceof KtIfExpression) {
-                target = ((KtIfExpression) expression).getIfKeyword();
-            }
-            else if (expression instanceof KtWhenExpression) {
-                target = ((KtWhenExpression) expression).getWhenKeyword();
-            }
-            holder.createInfoAnnotation(target, "Smart cast to " + DescriptorRenderer.FQ_NAMES_IN_TYPES.renderType(smartCast))
+            holder.createInfoAnnotation(getSmartCastTarget(expression),
+                                        "Smart cast to " + DescriptorRenderer.FQ_NAMES_IN_TYPES.renderType(smartCast))
                   .setTextAttributes(KotlinHighlightingColors.SMART_CAST_VALUE);
         }
 

idea/testData/checker/infos/smartCastOnElvis.kt

@@ -0,0 +1,15 @@
+fun foo(s: String) = s.length
+
+fun baz(s: String?, r: String?): Int {
+    return foo(r <info descr="Smart cast to kotlin.String">?:</info> when {
+        s != null -> s
+        else -> ""
+    })
+}
+
+fun bar(s: String?, r: String?): Int {
+    return (r <info descr="Smart cast to kotlin.String">?:</info> when {
+        s != null -> s
+        else -> ""
+    }).length
+}

idea/tests/org/jetbrains/kotlin/checkers/PsiCheckerTestGenerated.java

@@ -724,6 +724,12 @@ public class PsiCheckerTestGenerated extends AbstractPsiCheckerTest {
             doTestWithInfos(fileName);
         }
 
+        @TestMetadata("smartCastOnElvis.kt")
+        public void testSmartCastOnElvis() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/checker/infos/smartCastOnElvis.kt");
+            doTestWithInfos(fileName);
+        }
+
         @TestMetadata("SmartCastOnIf.kt")
         public void testSmartCastOnIf() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/checker/infos/SmartCastOnIf.kt");