From bef38bbf1a4f9337f910a5c9cb8fdfefa1431950 Mon Sep 17 00:00:00 2001
From: Nikos Gorogiannis <nikosgorogiannis@fb.com>
Date: Fri, 4 May 2018 01:49:51 -0700
Subject: [PATCH] [racerd] recognise std::lock calls

Summary: std::lock allows for locking multiple lockable objects, while avoiding deadlock.  This will fix some FPs in C++.

Reviewed By: da319

Differential Revision: D7844198

fbshipit-source-id: 2b7140a
---
 infer/src/concurrency/RacerDConfig.ml         |  3 +-
 .../tests/codetoanalyze/cpp/racerd/issues.exp |  1 +
 .../codetoanalyze/cpp/racerd/std_lock.cpp     | 40 +++++++++++++++++++
 3 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 infer/tests/codetoanalyze/cpp/racerd/std_lock.cpp

diff --git a/infer/src/concurrency/RacerDConfig.ml b/infer/src/concurrency/RacerDConfig.ml
index 770113490..da7e3c181 100644
--- a/infer/src/concurrency/RacerDConfig.ml
+++ b/infer/src/concurrency/RacerDConfig.ml
@@ -67,7 +67,8 @@ module Models = struct
           ; "folly::SharedMutexImpl::lockExclusiveImpl"
           ; "folly::SharedMutexImpl::lockSharedImpl"
           ; "std::mutex::lock"
-          ; "std::unique_lock::lock" ]
+          ; "std::unique_lock::lock"
+          ; "std::lock" ]
       in
       let matcher_lock_constructor =
         QualifiedCppName.Match.of_fuzzy_qual_names
diff --git a/infer/tests/codetoanalyze/cpp/racerd/issues.exp b/infer/tests/codetoanalyze/cpp/racerd/issues.exp
index 4222172d4..95bf8a710 100644
--- a/infer/tests/codetoanalyze/cpp/racerd/issues.exp
+++ b/infer/tests/codetoanalyze/cpp/racerd/issues.exp
@@ -18,6 +18,7 @@ codetoanalyze/cpp/racerd/lock_guard_with_scope.cpp, basics::LockGuardWithScope_g
 codetoanalyze/cpp/racerd/lock_guard_with_scope.cpp, basics::LockGuardWithScope_get4, 0, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,access to `this.suspiciously_read`,<Write trace>,access to `this.suspiciously_read`]
 codetoanalyze/cpp/racerd/reporting.cpp, reporting::Basic_call1, 1, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,call to reporting::Basic_test,access to `xparam.x1.w`,<Write trace>,call to reporting::Basic_call1,call to reporting::Basic_test,access to `xparam.x1.w`]
 codetoanalyze/cpp/racerd/reporting.cpp, reporting::Basic_test_unlock, 0, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,call to reporting::Basic_call1,call to reporting::Basic_test,access to `xparam.x1.w`,<Write trace>,call to reporting::Basic_call1,call to reporting::Basic_test,access to `xparam.x1.w`]
+codetoanalyze/cpp/racerd/std_lock.cpp, basics::StdLock_get_bad, 0, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,access to `this.not_guarded`,<Write trace>,access to `this.not_guarded`]
 codetoanalyze/cpp/racerd/unique_lock.cpp, basics::UniqueLock_get2, 3, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,access to `this.suspiciously_written1`,<Write trace>,access to `this.suspiciously_written1`]
 codetoanalyze/cpp/racerd/unique_lock.cpp, basics::UniqueLock_get2, 4, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,access to `this.suspiciously_written2`,<Write trace>,access to `this.suspiciously_written2`]
 codetoanalyze/cpp/racerd/unique_lock.cpp, basics::UniqueLock_get4, 1, LOCK_CONSISTENCY_VIOLATION, ERROR, [<Read trace>,access to `this.suspiciously_read1`,<Write trace>,access to `this.suspiciously_read1`]
diff --git a/infer/tests/codetoanalyze/cpp/racerd/std_lock.cpp b/infer/tests/codetoanalyze/cpp/racerd/std_lock.cpp
new file mode 100644
index 000000000..e4e99a1d3
--- /dev/null
+++ b/infer/tests/codetoanalyze/cpp/racerd/std_lock.cpp
@@ -0,0 +1,40 @@
+/*
+ * 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 <mutex>
+
+namespace basics {
+
+class StdLock {
+ public:
+  StdLock() {}
+
+  void set_ok(StdLock* other) {
+    std::lock(mutex_, other->mutex_);
+    guarded = other->guarded;
+  }
+
+  int get_ok() {
+    mutex_.lock();
+    return guarded;
+  }
+
+  void set_bad(StdLock* other) {
+    std::lock(mutex_, other->mutex_);
+    not_guarded = other->not_guarded;
+  }
+
+  int get_bad() { return not_guarded; }
+
+ private:
+  int guarded;
+  int not_guarded;
+  std::mutex mutex_;
+};
+} // namespace basics