[lieveness] Fix false positive to do with a _Generic expression not being translated properly

Reviewed By: sblackshear

Differential Revision: D7169156

fbshipit-source-id: ab79bf9

facebook-clang-plugins

@@ -1 +1 @@
-Subproject commit 5f64a6842e9a85fc222f9a436c3d993cacb891b3
+Subproject commit 9d03cb460a30ad02d7b5edfa38f3a1143e642cfe

infer/src/clang/cFrontend_config.ml

@@ -93,6 +93,8 @@ let infer_skip_fun = "__infer_skip_function"
 
 let infer_skip_gcc_asm_stmt = "__infer_skip_gcc_asm_stmt"
 
+let infer_generic_selection_expr = "__infer_generic_selection_expr"
+
 let init = "init"
 
 let is_kind_of_class = "isKindOfClass:"

infer/src/clang/cFrontend_config.mli

@@ -88,6 +88,8 @@ val infer_skip_fun : string
 
 val infer_skip_gcc_asm_stmt : string
 
+val infer_generic_selection_expr : string
+
 val init : string
 
 val is_kind_of_class : string

infer/src/clang/cTrans.ml

@@ -2943,6 +2943,11 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
     call_function_with_args "GCCAsmStmt" pname trans_state
 
 
+  and genericSelectionExprUnknown_trans trans_state =
+    let pname = Typ.Procname.from_string_c_fun CFrontend_config.infer_generic_selection_expr in
+    call_function_with_args "GenericSelectionExpr" pname trans_state
+
+
   and objc_cxx_throw_trans trans_state =
     call_function_with_args "ObjCCPPThrow" BuiltinDecl.objc_cpp_throw trans_state
 
@@ -3272,8 +3277,12 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
         cxxDefaultExpr_trans trans_state default_expr_info
     | ImplicitValueInitExpr (stmt_info, _, _) ->
         implicitValueInitExpr_trans trans_state stmt_info
-    | GenericSelectionExpr _
-    (* to be fixed when we dump the right info in the ast *)
+    | GenericSelectionExpr (stmt_info, stmts, _, gse_info) -> (
+      match gse_info.gse_value with
+      | Some value ->
+          instruction trans_state value
+      | None ->
+          genericSelectionExprUnknown_trans trans_state stmt_info stmts )
     | SizeOfPackExpr _ ->
         {empty_res_trans with exps= [(Exp.get_undefined false, Typ.mk Tvoid)]}
     | GCCAsmStmt (stmt_info, stmts) ->

infer/tests/codetoanalyze/c/frontend/unusual_exps/generic_exp.c.dot

@@ -7,11 +7,11 @@ digraph cfg {
 "test_typename.b2359812ef4a83b4e2638a11e6c522b3_2" [label="2: Exit test_typename \n  " color=yellow style=filled]
 	
 
-"test_typename.b2359812ef4a83b4e2638a11e6c522b3_3" [label="3:  DeclStmt \n   *&z:void=_t$0 [line 16, column 3]\n " shape="box"]
+"test_typename.b2359812ef4a83b4e2638a11e6c522b3_3" [label="3:  DeclStmt \n   *&z:int=3 [line 16, column 3]\n " shape="box"]
 	
 
 	 "test_typename.b2359812ef4a83b4e2638a11e6c522b3_3" -> "test_typename.b2359812ef4a83b4e2638a11e6c522b3_2" ;
-"test_typename.b2359812ef4a83b4e2638a11e6c522b3_4" [label="4:  DeclStmt \n   *&x:void=_t$1 [line 15, column 3]\n " shape="box"]
+"test_typename.b2359812ef4a83b4e2638a11e6c522b3_4" [label="4:  DeclStmt \n   *&x:int=2 [line 15, column 3]\n " shape="box"]
 	
 
 	 "test_typename.b2359812ef4a83b4e2638a11e6c522b3_4" -> "test_typename.b2359812ef4a83b4e2638a11e6c522b3_3" ;

infer/tests/codetoanalyze/objc/liveness/GenericExprExample.m

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018 - 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.
+ */
+#import <Foundation/Foundation.h>
+
+static float generic_expr_ok() {
+  NSString* currentValue = [NSString new];
+  return _Generic(0.2f, float : [currentValue floatValue]);
+};