From 2228f7448d69200e9494c333f7fd4bb8d7b538c6 Mon Sep 17 00:00:00 2001
From: Jeremy Dubreil <jrm@fb.com>
Date: Mon, 5 Feb 2018 12:20:49 -0800
Subject: [PATCH] [infer][nullable checker] add tests for the early return

Reviewed By: sblackshear

Differential Revision: D6891113

fbshipit-source-id: a614641
---
 infer/tests/codetoanalyze/cpp/nullable/issues.exp      |  2 ++
 infer/tests/codetoanalyze/cpp/nullable/method.cpp      |  7 +++++++
 .../codetoanalyze/java/checkers/NullableViolation.java |  7 +++++++
 infer/tests/codetoanalyze/objc/nullable/Examples.m     | 10 ++++++++++
 4 files changed, 26 insertions(+)

diff --git a/infer/tests/codetoanalyze/cpp/nullable/issues.exp b/infer/tests/codetoanalyze/cpp/nullable/issues.exp
index f93a740c7..f7197d9b2 100644
--- a/infer/tests/codetoanalyze/cpp/nullable/issues.exp
+++ b/infer/tests/codetoanalyze/cpp/nullable/issues.exp
@@ -20,6 +20,8 @@ codetoanalyze/cpp/nullable/method.cpp, methodAlwaysCheckedForNullOkay, 1, NULL_T
 codetoanalyze/cpp/nullable/method.cpp, methodAlwaysCheckedForNullOkay, 2, NULL_DEREFERENCE, [start of procedure methodAlwaysCheckedForNullOkay(),Condition is true,start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is true,start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject]
 codetoanalyze/cpp/nullable/method.cpp, methodCallOnFieldOfNullableObjectBad, 2, NULLABLE_DEREFERENCE, [dereference of &p,assignment of the nullable value,definition of mayReturnNullObject]
 codetoanalyze/cpp/nullable/method.cpp, methodCallOnFieldOfNullableObjectBad, 2, NULL_DEREFERENCE, [start of procedure methodCallOnFieldOfNullableObjectBad(),start of procedure mayReturnNullObject,Condition is true,return from a call to T_mayReturnNullObject]
+codetoanalyze/cpp/nullable/method.cpp, methodCheckedForNullAndReturnOkay, 1, NULL_TEST_AFTER_DEREFERENCE, [start of procedure methodCheckedForNullAndReturnOkay(),start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is false]
+codetoanalyze/cpp/nullable/method.cpp, methodCheckedForNullAndReturnOkay, 4, NULL_DEREFERENCE, [start of procedure methodCheckedForNullAndReturnOkay(),start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is false,start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject]
 codetoanalyze/cpp/nullable/method.cpp, methodCheckedForNullOkay, 1, NULL_TEST_AFTER_DEREFERENCE, [start of procedure methodCheckedForNullOkay(),start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is false]
 codetoanalyze/cpp/nullable/method.cpp, methodCheckedForNullOkay, 2, NULL_DEREFERENCE, [start of procedure methodCheckedForNullOkay(),start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is true,start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject]
 codetoanalyze/cpp/nullable/method.cpp, methodNotAlwaysCheckedForNullBad, 1, NULL_TEST_AFTER_DEREFERENCE, [start of procedure methodNotAlwaysCheckedForNullBad(),Condition is false,start of procedure mayReturnNullObject,Condition is false,return from a call to T_mayReturnNullObject,Condition is false]
diff --git a/infer/tests/codetoanalyze/cpp/nullable/method.cpp b/infer/tests/codetoanalyze/cpp/nullable/method.cpp
index 2aef93620..a582ee757 100644
--- a/infer/tests/codetoanalyze/cpp/nullable/method.cpp
+++ b/infer/tests/codetoanalyze/cpp/nullable/method.cpp
@@ -97,6 +97,13 @@ void methodCheckedForNullOkay(T* t) {
   }
 }
 
+void methodCheckedForNullAndReturnOkay(T* t) {
+  if (t->mayReturnNullObject() == nullptr) {
+    return;
+  }
+  t->mayReturnNullObject()->doSomething(); // does not report here
+}
+
 void reportsViolationOutsideOfNullCheckBad(T* t) {
   if (t->mayReturnNullObject() != nullptr) {
     t->mayReturnNullObject()->doSomething(); // does not report here
diff --git a/infer/tests/codetoanalyze/java/checkers/NullableViolation.java b/infer/tests/codetoanalyze/java/checkers/NullableViolation.java
index 403e3feb4..991bfa2d5 100644
--- a/infer/tests/codetoanalyze/java/checkers/NullableViolation.java
+++ b/infer/tests/codetoanalyze/java/checkers/NullableViolation.java
@@ -43,6 +43,13 @@ public class NullableViolation {
     }
   }
 
+  void nullableMethodCheckedForNullAndReturnOkay() {
+    if (returnsNullable() == null) {
+        return;
+    }
+    returnsNullable().doSomething(); // does not report here
+  }
+
   void dereferenceNullableMethodIncorrectlyCheckedForNullBad() {
     if (returnsNullable() == null) {
       returnsNullable().doSomething(); // reports here
diff --git a/infer/tests/codetoanalyze/objc/nullable/Examples.m b/infer/tests/codetoanalyze/objc/nullable/Examples.m
index 4c7bb9ab7..eed1acee9 100644
--- a/infer/tests/codetoanalyze/objc/nullable/Examples.m
+++ b/infer/tests/codetoanalyze/objc/nullable/Examples.m
@@ -129,6 +129,16 @@ typedef struct s_ {
   return array;
 }
 
+- (NSArray*)nullableMethodCheckedForNullAndReturnOkay {
+  NSObject* nullableObject = [self nullableMethod];
+  NSArray* array;
+  if (nullableObject == nil) {
+    return array;
+  }
+  array = @[ nullableObject ]; // does not report here
+  return array;
+}
+
 - (NSArray*)secondElementNullableObjectInNSArrayBad {
   NSObject* allocatedObject = [NSObject alloc];
   NSObject* nullableObject = [self nullableMethod];