From 562f9d1c7cad03a9cff372bdfe731c9ba354f943 Mon Sep 17 00:00:00 2001
From: Martin Trojer <mtrojer@fb.com>
Date: Wed, 1 Aug 2018 07:07:24 -0700
Subject: [PATCH] Add guard against triggering static self logic when we have
 nested class calls

Reviewed By: jvillard

Differential Revision: D9116721

fbshipit-source-id: 8d6f4a98d
---
 infer/src/clang/cTrans.ml                     | 13 +++----
 .../objc/liveness/NestedClassCalls.m          | 35 +++++++++++++++++++
 .../codetoanalyze/objc/liveness/issues.exp    |  1 +
 3 files changed, 43 insertions(+), 6 deletions(-)
 create mode 100644 infer/tests/codetoanalyze/objc/liveness/NestedClassCalls.m

diff --git a/infer/src/clang/cTrans.ml b/infer/src/clang/cTrans.ml
index c9dcd10a2..304b40a82 100644
--- a/infer/src/clang/cTrans.ml
+++ b/infer/src/clang/cTrans.ml
@@ -1195,6 +1195,8 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
         None
 
 
+  and is_receiver_instance = function `Instance | `SuperInstance -> true | _ -> false
+
   and objCMessageExpr_trans_special_cases trans_state si obj_c_message_expr_info method_type
       trans_state_pri sil_loc act_params =
     let context = trans_state.context in
@@ -1206,7 +1208,8 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
         CMethod_trans.get_class_name_method_call_from_receiver_kind context obj_c_message_expr_info
           act_params
       in
-      if trans_state.is_fst_arg_objc_instance_method_call then
+      if trans_state.is_fst_arg_objc_instance_method_call && is_receiver_instance receiver_kind
+      then
         raise
           (Self.SelfClassException
              {class_name; position= __POS__; source_range= si.Clang_ast_t.si_source_range})
@@ -1241,11 +1244,9 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
         in
         try
           let trans_state_param' =
-            match obj_c_message_expr_info.Clang_ast_t.omei_receiver_kind with
-            | `Instance | `SuperInstance ->
-                {trans_state_param with is_fst_arg_objc_instance_method_call= true}
-            | _ ->
-                {trans_state_param with is_fst_arg_objc_instance_method_call= false}
+            if is_receiver_instance obj_c_message_expr_info.Clang_ast_t.omei_receiver_kind then
+              {trans_state_param with is_fst_arg_objc_instance_method_call= true}
+            else {trans_state_param with is_fst_arg_objc_instance_method_call= false}
           in
           let fst_res_trans = instruction trans_state_param' stmt in
           (obj_c_message_expr_info, fst_res_trans :: param_trans_results)
diff --git a/infer/tests/codetoanalyze/objc/liveness/NestedClassCalls.m b/infer/tests/codetoanalyze/objc/liveness/NestedClassCalls.m
new file mode 100644
index 000000000..605221a4a
--- /dev/null
+++ b/infer/tests/codetoanalyze/objc/liveness/NestedClassCalls.m
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2018-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+#import <Foundation/NSObject.h>
+
+@interface A : NSObject
+@property int val;
+@end
+
+bool myrand();
+
+@implementation A
+- (instancetype)myDoO:(id)o {
+  return self;
+}
++ (instancetype)initWithVal:(int)v {
+  A* a = [A alloc];
+  a.val = v;
+  return a;
+}
++ (instancetype)nestedGood {
+  const BOOL isB = myrand();
+  return [[[A initWithVal:isB ? 0 : 1] myDoO:[NSObject class]]
+      myDoO:[NSObject class]];
+}
+
++ (instancetype)nestedBad {
+  const BOOL isB = myrand();
+  return [[[A initWithVal:42] myDoO:[NSObject class]] myDoO:[NSObject class]];
+}
+
+@end
diff --git a/infer/tests/codetoanalyze/objc/liveness/issues.exp b/infer/tests/codetoanalyze/objc/liveness/issues.exp
index e69de29bb..fdf0fad36 100644
--- a/infer/tests/codetoanalyze/objc/liveness/issues.exp
+++ b/infer/tests/codetoanalyze/objc/liveness/issues.exp
@@ -0,0 +1 @@
+codetoanalyze/objc/liveness/NestedClassCalls.m, A_nestedBad, 1, DEAD_STORE, no_bucket, ERROR, [Write of unused value]