From 1edcbce35bfe64a8523b49e0a314268bc27512dd Mon Sep 17 00:00:00 2001
From: Jia Chen <grievejia@fb.com>
Date: Fri, 16 Jun 2017 17:14:15 -0700
Subject: [PATCH] Whitelist std::swap in C++ analyses

Reviewed By: jeremydubreil

Differential Revision: D5269267

fbshipit-source-id: 00a4ba8
---
 infer/src/base/Config.ml                      |  1 +
 .../tests/codetoanalyze/cpp/errors/issues.exp |  1 +
 .../codetoanalyze/cpp/errors/models/swap.cpp  | 23 +++++++++++++++++++
 3 files changed, 25 insertions(+)
 create mode 100644 infer/tests/codetoanalyze/cpp/errors/models/swap.cpp

diff --git a/infer/src/base/Config.ml b/infer/src/base/Config.ml
index 92197e594..5025eb09f 100644
--- a/infer/src/base/Config.ml
+++ b/infer/src/base/Config.ml
@@ -236,6 +236,7 @@ let whitelisted_cpp_methods = [
   "std::forward";
   "std::min";
   "std::max";
+  "std::swap";
   "google::CheckNotNull";
 ]
 
diff --git a/infer/tests/codetoanalyze/cpp/errors/issues.exp b/infer/tests/codetoanalyze/cpp/errors/issues.exp
index 1b075cdae..0086142d6 100644
--- a/infer/tests/codetoanalyze/cpp/errors/issues.exp
+++ b/infer/tests/codetoanalyze/cpp/errors/issues.exp
@@ -18,6 +18,7 @@ codetoanalyze/cpp/errors/memory_leaks/object_leak.cpp, object_leak, 0, MEMORY_LE
 codetoanalyze/cpp/errors/memory_leaks/raii_malloc.cpp, memory_leak, 0, MEMORY_LEAK, [start of procedure memory_leak()]
 codetoanalyze/cpp/errors/models/move.cpp, move::div0_moved_from, 3, DIVIDE_BY_ZERO, [start of procedure move::div0_moved_from(),start of procedure X,return from a call to move::X_X,start of procedure X,return from a call to move::X_X]
 codetoanalyze/cpp/errors/models/move.cpp, move::div0_moved_to, 3, DIVIDE_BY_ZERO, [start of procedure move::div0_moved_to(),start of procedure X,return from a call to move::X_X,start of procedure X,return from a call to move::X_X]
+codetoanalyze/cpp/errors/models/swap.cpp, swap_null_bad, 4, NULL_DEREFERENCE, [start of procedure swap_null_bad()]
 codetoanalyze/cpp/errors/mutex/std_mutex.cpp, alarm1, 2, DOUBLE_LOCK, [start of procedure alarm1()]
 codetoanalyze/cpp/errors/mutex/std_mutex.cpp, alarm2, 2, DOUBLE_LOCK, [start of procedure alarm2()]
 codetoanalyze/cpp/errors/mutex/std_mutex.cpp, alarm2, 2, DOUBLE_LOCK, [start of procedure alarm2()]
diff --git a/infer/tests/codetoanalyze/cpp/errors/models/swap.cpp b/infer/tests/codetoanalyze/cpp/errors/models/swap.cpp
new file mode 100644
index 000000000..37eb4fa45
--- /dev/null
+++ b/infer/tests/codetoanalyze/cpp/errors/models/swap.cpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2017 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+#include <utility>
+
+int swap_null_ok() {
+  int a = 0;
+  int *p = nullptr, *q = &a;
+  std::swap(p, q);
+  return *p;
+}
+
+int swap_null_bad() {
+  int a = 0;
+  int *p = nullptr, *q = &a;
+  std::swap(p, q);
+  return *q;
+}