[infer][clang] port the nullable suggestion on fields on C++

Summary:
Suggesting to add `_Nullable` on the fields checked for, or assigned to, `nullptr` will allow the biabduction analysis to report null dereferences that are related to the lifetime of objects.

Depends on D5832147

Reviewed By: sblackshear

Differential Revision: D5836538

fbshipit-source-id: c1b8e48

Makefile

@@ -46,7 +46,7 @@ BUILD_SYSTEMS_TESTS += \
 
 DIRECT_TESTS += \
   c_biabduction c_bufferoverrun c_errors c_frontend \
-  cpp_bufferoverrun cpp_errors cpp_frontend  cpp_liveness cpp_quandary cpp_siof cpp_threadsafety \
+  cpp_bufferoverrun cpp_errors cpp_frontend  cpp_liveness cpp_quandary cpp_siof cpp_threadsafety cpp_nullable \
 
 ifneq ($(BUCK),no)
 BUILD_SYSTEMS_TESTS += buck-clang-db buck_flavors buck_flavors_run buck_flavors_deterministic

infer/src/checkers/NullabilitySuggest.ml

@@ -145,6 +145,9 @@ let pretty_field_name proc_data field_name =
       Typ.Fieldname.to_string field_name
 
 let checker {Callbacks.summary; proc_desc; tenv} =
+  let nullable_annotation =
+    if Typ.Procname.is_java (Procdesc.get_proc_name proc_desc) then "@Nullable" else "_Nullable"
+  in
   let report astate (proc_data: extras ProcData.t) =
     let report_access_path ap udchain =
       let issue_kind = IssueType.field_should_be_nullable.unique_id in
@@ -156,7 +159,7 @@ let checker {Callbacks.summary; proc_desc; tenv} =
        -> (
           let message =
             F.asprintf "Field %a should be annotated with %a" MF.pp_monospaced
-              (pretty_field_name proc_data field_name) MF.pp_monospaced "@Nullable"
+              (pretty_field_name proc_data field_name) MF.pp_monospaced nullable_annotation
           in
           let exn = Exceptions.Checkers (issue_kind, Localise.verbatim_desc message) in
           match make_error_trace astate ap udchain with

infer/src/checkers/registerCheckers.ml

@@ -43,7 +43,8 @@ let checkers =
   ; ("printf args", Config.printf_args, [(Procedure PrintfArgs.callback_printf_args, Config.Java)])
   ; ( "nullable suggestion"
     , Config.suggest_nullable
-    , [(Procedure NullabilitySuggest.checker, Config.Java)] )
+    , [ (Procedure NullabilitySuggest.checker, Config.Java)
+      ; (Procedure NullabilitySuggest.checker, Config.Clang) ] )
   ; ( "quandary"
     , Config.quandary
     , [ (Procedure JavaTaintAnalysis.checker, Config.Java)

infer/tests/codetoanalyze/cpp/nullable/Makefile

@@ -0,0 +1,21 @@
+# Copyright (c) 2016 - 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.
+
+TESTS_DIR = ../../..
+
+ANALYZER = checkers
+# see explanations in cpp/errors/Makefile for the custom isystem
+CLANG_OPTIONS = -x c++ -std=c++11 -nostdinc++ -isystem$(ROOT_DIR) -isystem$(CLANG_INCLUDES)/c++/v1/ -c
+INFER_OPTIONS = --biabduction --suggest-nullable --debug-exceptions --project-root $(TESTS_DIR)
+INFER_OPTIONS += --debug
+INFERPRINT_OPTIONS = --issues-tests
+
+SOURCES = $(wildcard *.cpp)
+
+include $(TESTS_DIR)/clang.make
+
+infer-out/report.json: $(MAKEFILE_LIST)

infer/tests/codetoanalyze/cpp/nullable/example.cpp

@@ -0,0 +1,34 @@
+/*
+ * 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.
+ */
+class T {
+ private:
+  int* _Nullable nullable_field;
+  int* unnanotated_field;
+
+ public:
+  void assign_nullable_field_to_null_okay() { nullable_field = nullptr; }
+
+ public:
+  void assign_unnanotated_field_to_null_bad() { unnanotated_field = nullptr; }
+
+ public:
+  void test_nullable_field_for_null_okay() {
+    if (nullable_field == nullptr) {
+    }
+  }
+
+ public:
+  void test_unnanotated_field_for_null_bad() {
+    if (unnanotated_field == nullptr) {
+    }
+  }
+
+ public:
+  void FN_dereference_nullable_field_bad() { *nullable_field = 42; }
+};

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

@@ -0,0 +1,4 @@
+codetoanalyze/cpp/nullable/example.cpp, T_assign_nullable_field_to_null_okay, 0, FIELD_SHOULD_BE_NULLABLE, [Field nullable_field is assigned null here]
+codetoanalyze/cpp/nullable/example.cpp, T_assign_unnanotated_field_to_null_bad, 0, FIELD_SHOULD_BE_NULLABLE, [Field unnanotated_field is assigned null here]
+codetoanalyze/cpp/nullable/example.cpp, T_test_nullable_field_for_null_okay, 1, FIELD_SHOULD_BE_NULLABLE, [Field nullable_field is compared to null here]
+codetoanalyze/cpp/nullable/example.cpp, T_test_unnanotated_field_for_null_bad, 1, FIELD_SHOULD_BE_NULLABLE, [Field unnanotated_field is compared to null here]