[ThreadSafety] Do not report for c++ classes that do not have mutex member.

Reviewed By: jberdine

Differential Revision: D5182255

fbshipit-source-id: f954337

infer/src/checkers/ThreadSafety.ml

@@ -1223,17 +1223,29 @@ let report_unsafe_accesses ~is_file_threadsafe aggregated_access_map =
          List.exists
            ~f:(fun (_, _, _, tenv, pdesc) -> is_thread_safe_method pdesc tenv)
            grouped_accesses in
-       (* report if
-          - the method/class of the access is thread-safe (or an override or superclass is), or
-          - any access is in a field marked thread-safe (or an override) *)
+       let class_has_mutex_member objc_cpp tenv =
+         let class_name = Typ.Procname.objc_cpp_get_class_type_name objc_cpp in
+         let matcher = QualifiedCppName.Match.of_fuzzy_qual_names ["std::mutex"] in
+         Option.exists (Tenv.lookup tenv class_name) ~f:(fun class_str ->
+             (* check if the class contains a member of type std::mutex *)
+             List.exists (class_str.Typ.Struct.fields) ~f:(fun (_, ft, _) ->
+                 Option.exists (Typ.name ft) ~f:(fun name ->
+                     QualifiedCppName.Match.match_qualifiers matcher (Typ.Name.qual_name name))
+               )
+           ) in
        let should_report pdesc tenv =
          match Procdesc.get_proc_name pdesc with
          | Java _ ->
+             (* report if
+                - the method/class of the access is thread-safe
+                  (or an override or superclass is), or
+                - any access is in a field marked thread-safe (or an override) *)
              ((is_file_threadsafe || accessed_by_threadsafe_method)
               && should_report_on_proc pdesc tenv)
              || is_thread_safe_method pdesc tenv
-         | ObjC_Cpp _ ->
-             true
+         | ObjC_Cpp objc_cpp ->
+             (* report if the class has a mutex member  *)
+             class_has_mutex_member objc_cpp tenv
          | _ ->
              false
        in

infer/tests/codetoanalyze/cpp/threadsafety/basics_no_mutex.cpp

@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+
+namespace basics {
+
+class BasicsNoMutex {
+ public:
+  BasicsNoMutex() {}
+
+  void set(int new_value) {
+    field_1 = new_value;
+    field_2 = new_value;
+    field_3 = new_value;
+  }
+
+  int get1() { return field_1; }
+
+  int get2() { return field_2; }
+
+ private:
+  int field_1;
+  int field_2;
+  int field_3;
+};
+}

infer/tests/codetoanalyze/cpp/threadsafety/basics_with_mutex.cpp

@@ -0,0 +1,32 @@
+/*
+ * 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 BasicsWithHeader {
+ public:
+  BasicsWithHeader(){};
+
+  void set(int new_value) {
+    field_1 = new_value;
+    field_2 = new_value;
+    field_3 = new_value;
+  };
+  int get1() { return field_1; };
+  int get2() { return field_2; };
+
+ private:
+  int field_1;
+  int field_2;
+  int field_3;
+  std::mutex mutex_;
+};
+}

infer/tests/codetoanalyze/cpp/threadsafety/issues.exp

@@ -1,3 +1,5 @@
 codetoanalyze/cpp/threadsafety/basics.cpp, basics::Basic_get2, 3, THREAD_SAFETY_VIOLATION, [access to `suspiciously_written`]
 codetoanalyze/cpp/threadsafety/basics.cpp, basics::Basic_get3, 0, THREAD_SAFETY_VIOLATION, [<Beginning of read trace>,access to `not_guarded`,<Beginning of write trace>,access to `not_guarded`]
 codetoanalyze/cpp/threadsafety/basics.cpp, basics::Basic_get4, 0, THREAD_SAFETY_VIOLATION, [<Beginning of read trace>,access to `suspiciously_read`,<Beginning of write trace>,access to `suspiciously_read`]
+codetoanalyze/cpp/threadsafety/basics_with_mutex.cpp, basics::BasicsWithHeader_get1, 0, THREAD_SAFETY_VIOLATION, [<Beginning of read trace>,access to `field_1`,<Beginning of write trace>,access to `field_1`]
+codetoanalyze/cpp/threadsafety/basics_with_mutex.cpp, basics::BasicsWithHeader_get2, 0, THREAD_SAFETY_VIOLATION, [<Beginning of read trace>,access to `field_2`,<Beginning of write trace>,access to `field_2`]