From 8ac5d7c7d3c4b26dc7e7093d169e3ec86eff7ca4 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 14 Aug 2017 15:40:16 +0200
Subject: [PATCH] IDEA-177404 Method that never returns get "returns non-null
 value" warning

---
 .../codeInspection/dataFlow/DataFlowInspectionBase.java  | 9 +++++----
 .../dataFlow/fixture/NullableMethodReturningNotNull.java | 7 ++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspectionBase.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspectionBase.java
index 85c457eb2077..1e660900cab7 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspectionBase.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspectionBase.java
@@ -348,7 +348,7 @@ public class DataFlowInspectionBase extends BaseJavaBatchLocalInspectionTool {
       reportConstantReferenceValues(holder, visitor, reportedAnchors);
     }
 
-    if (REPORT_NULLABLE_METHODS_RETURNING_NOT_NULL && visitor.isAlwaysReturnsNotNull()) {
+    if (REPORT_NULLABLE_METHODS_RETURNING_NOT_NULL && visitor.isAlwaysReturnsNotNull(runner.getInstructions())) {
       reportAlwaysReturnsNotNull(holder, scope);
     }
   }
@@ -410,7 +410,7 @@ public class DataFlowInspectionBase extends BaseJavaBatchLocalInspectionTool {
     PsiJavaCodeReferenceElement annoName = nullableAnno.getNameReferenceElement();
     assert annoName != null;
     String msg = "@" + NullableStuffInspectionBase.getPresentableAnnoName(nullableAnno) +
-                 " method '" + method.getName() + "' always return a non-null value";
+                 " method '" + method.getName() + "' always returns a non-null value";
     holder.registerProblem(annoName, msg, new AddNotNullAnnotationFix(method));
   }
 
@@ -976,8 +976,9 @@ public class DataFlowInspectionBase extends BaseJavaBatchLocalInspectionTool {
       return StreamEx.ofKeys(myFailingCalls, v -> v).map(MethodCallInstruction::getCallExpression).toList();
     }
 
-    boolean isAlwaysReturnsNotNull() {
-      return myAlwaysReturnsNotNull;
+    boolean isAlwaysReturnsNotNull(Instruction[] instructions) {
+      return myAlwaysReturnsNotNull &&
+             ContainerUtil.exists(instructions, i -> i instanceof ReturnInstruction && ((ReturnInstruction)i).getAnchor() instanceof PsiReturnStatement);
     }
 
     @Override
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/NullableMethodReturningNotNull.java b/java/java-tests/testData/inspection/dataFlow/fixture/NullableMethodReturningNotNull.java
index 70a7444bf308..3f04edada161 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/NullableMethodReturningNotNull.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/NullableMethodReturningNotNull.java
@@ -1,7 +1,7 @@
 import org.jetbrains.annotations.*;
 
 final class Foo {
-  @<warning descr="@Nullable method 'foo' always return a non-null value">Nullable</warning> Object foo(int param) {
+  @<warning descr="@Nullable method 'foo' always returns a non-null value">Nullable</warning> Object foo(int param) {
     return param == 1 ? new Object() {
       Object unrelated() {
         return <warning descr="'null' is returned by the method which is not declared as @Nullable">null</warning>;
@@ -12,4 +12,9 @@ final class Foo {
   @NotNull Foo bar() {
     return this;
   }
+
+  @Nullable
+  Object throwing() {
+    throw new UnsupportedOperationException();
+  }
 }