[clang] Add is_instance as part of the type of objc methods

Summary:
The methods in objc can have the same name in the same class, but one be instance and the other class,
so that we need to take the instance flag into account when defining unique names for ObjC methods.

infer/src/backend/procname.ml

@@ -30,6 +30,19 @@ type java_signature = {
   kind: method_kind
 }
 
+type objc_method_kind =
+  | Instance_objc_method
+  | Class_objc_method
+
+let mangled_of_objc_method_kind kind =
+  match kind with
+  | Instance_objc_method -> Some "instance"
+  | Class_objc_method -> Some "class"
+
+let objc_method_kind_of_bool is_instance =
+  if is_instance then Instance_objc_method
+  else Class_objc_method
+
 (* C++/ObjC method signature *)
 type c_method_signature = {
   class_name: string;
@@ -117,10 +130,19 @@ let java_sig_compare js1 js2 =
   |> next java_return_type_compare js1.returntype js2.returntype
   |> next method_kind_compare js1.kind js2.kind
 
+let c_function_mangled_compare mangled1 mangled2 =
+  match mangled1, mangled2 with
+  | Some mangled1, None -> 1
+  | None, Some mangled2 -> -1
+  | None, None -> 0
+  | Some mangled1, Some mangled2 ->
+      string_compare mangled1 mangled2
+
 (** Compare c_method signatures. *)
 let c_meth_sig_compare osig1 osig2 =
-  let n = string_compare osig1.class_name osig2.class_name in
+  string_compare osig1.method_name osig2.method_name
-  if n <> 0 then n else string_compare osig1.method_name osig2.method_name
+  |> next string_compare osig1.class_name osig2.class_name
+  |> next c_function_mangled_compare osig1.mangled osig2.mangled
 
 (** Given a package.classname string, it looks for the latest dot and split the string in two (package, classname) *)
 let split_classname package_classname =
@@ -357,9 +379,9 @@ let to_readable_string (c1, c2) verbose =
 
 let c_method_to_string osig detail_level =
   match detail_level with
-  | SIMPLE ->
+  | SIMPLE -> osig.method_name
-      osig.method_name
+  | NON_VERBOSE -> osig.class_name ^ "_" ^ osig.method_name
-  | VERBOSE | NON_VERBOSE ->
+  | VERBOSE ->
       let m_str = match osig.mangled with
         | None -> ""
         | Some s -> "{" ^ s ^ "}" in

infer/src/backend/procname.mli

@@ -21,6 +21,16 @@ type method_kind =
   | Static (* in Java, procedures called with invokestatic *)
   | Non_Static (* in Java, procedures called with invokevirtual, invokespecial, and invokeinterface *)
 
+type objc_method_kind =
+  | Instance_objc_method (* for instance methods in ObjC *)
+  | Class_objc_method (* for class methods in ObjC *)
+
+(** Mangled string for method types  *)
+val mangled_of_objc_method_kind : objc_method_kind -> string option
+
+(** Create ObjC method type from a bool is_instance *)
+val objc_method_kind_of_bool : bool -> objc_method_kind
+
 (** Comparison for proc names *)
 val compare : t -> t -> int
 

infer/src/backend/symExec.ml

@@ -511,13 +511,11 @@ let check_inherently_dangerous_function caller_pname callee_pname =
     let pre_opt = State.get_normalized_pre (Abs.abstract_no_symop caller_pname) in
     Reporting.log_warning caller_pname ~pre: pre_opt exn
 
-
 let is_defined cfg pname =
   match Cfg.Procdesc.find_from_name cfg pname with
   | None -> false
   | Some pdesc -> Cfg.Procdesc.is_defined pdesc
 
-
 let call_should_be_skipped callee_pname summary =
   (* skip all procedures in intra-precedural mode *)
   !Config.intraprocedural
@@ -528,7 +526,6 @@ let call_should_be_skipped callee_pname summary =
   (* treat calls with no specs as skip functions in angelic mode *)
   || (!Config.angelic_execution && Specs.get_specs_from_payload summary == [])
 
-
 let report_raise_memory_leak tenv msg hpred prop =
   L.d_strln msg;
   L.d_increase_indent 1;
@@ -663,7 +660,6 @@ let method_exists right_proc_name methods =
   else (* ObjC case *)
     Specs.summary_exists right_proc_name
 
-
 let resolve_method tenv class_name proc_name =
   let found_class =
     let visited = ref Mangled.MangledSet.empty in
@@ -694,7 +690,6 @@ let resolve_method tenv class_name proc_name =
       proc_name
   | Some proc_name -> proc_name
 
-
 let resolve_typename prop arg =
   let (arg_exp, _) = arg in
   let typexp_opt =
@@ -707,7 +702,6 @@ let resolve_typename prop arg =
   | Some (Sil.Sizeof (Sil.Tstruct (_, _, Sil.Class, class_name_opt, _, _, _), _)) -> class_name_opt
   | _ -> None
 
-
 (** If the dynamic type of the object calling a method is known, the method from the dynamic type
     is called *)
 let resolve_virtual_pname cfg tenv prop args pname : Procname.t =
@@ -1261,7 +1255,6 @@ and sym_exe_check_variadic_sentinel ?(fails_on_nil=false) cfg pdesc tenv prop pa
   (* error on the first premature nil argument *)
   list_fold_left check_allocated [(prop, path)] non_terminal_argsi
 
-
 and sym_exe_check_variadic_sentinel_if_present cfg pdesc tenv prop path actual_params callee_pname loc =
   match Cfg.Procdesc.find_from_name cfg callee_pname with
   | None -> [(prop, path)]
@@ -2321,12 +2314,14 @@ module ModelBuiltins = struct
     execute_objc_NSArray_alloc_no_fail cfg pdesc tenv res' ret_ids loc
 
   let _ =
+    let method_kind = Procname.mangled_of_objc_method_kind Procname.Class_objc_method in
     Builtin.register_procname
-      (Procname.mangled_c_method "NSArray" "arrayWithObjects:count:" None)
+      (Procname.mangled_c_method "NSArray" "arrayWithObjects:count:" method_kind)
       execute_NSArray_arrayWithObjects_count
   let _ =
+    let method_kind = Procname.mangled_of_objc_method_kind Procname.Class_objc_method in
     Builtin.register_procname
-      (Procname.mangled_c_method "NSArray" "arrayWithObjects:" None)
+      (Procname.mangled_c_method "NSArray" "arrayWithObjects:" method_kind)
       execute_NSArray_arrayWithObjects
 end
 (* ============== END of ModelBuiltins ============== *)

infer/src/clang/cMethod_decl.ml

@@ -171,7 +171,9 @@ struct
   let process_objc_method_decl tenv cg cfg namespace curr_class decl_info name_info method_decl_info =
     let class_name = CContext.get_curr_class_name curr_class in
     let method_name = name_info.Clang_ast_t.ni_name in
-    let procname = CMethod_trans.mk_procname_from_method class_name method_name in
+    let is_instance = method_decl_info.Clang_ast_t.omdi_is_instance_method in
+    let method_kind = Procname.objc_method_kind_of_bool is_instance in
+    let procname = CMethod_trans.mk_procname_from_method class_name method_name method_kind in
     let method_decl = Meth_decl_info (method_decl_info, class_name) in
     let is_generated = Ast_utils.is_generated name_info in
     let ms = build_method_signature decl_info procname method_decl false false is_generated in

infer/src/clang/cMethod_trans.ml

@@ -30,25 +30,9 @@ let mk_procname_from_function name type_name =
   let type_name_crc = CRC.crc16 type_name in
   Procname.mangled_c_fun name type_name_crc
 
-let mk_procname_from_method class_name method_name =
+let mk_procname_from_method class_name method_name method_kind =
-  Procname.mangled_c_method class_name method_name None
+  let mangled = Procname.mangled_of_objc_method_kind method_kind in
-
+  Procname.mangled_c_method class_name method_name mangled
-let resolve_method_class tenv class_name method_name =
-  let type_name = Sil.TN_csu (Sil.Class, class_name) in
-  match Sil.tenv_lookup tenv type_name with
-  | Some (Sil.Tstruct (_, _, Sil.Class, cls, super_classes, methods, iann)) ->
-      Some type_name
-  | _ -> None
-
-let resolve_method tenv class_name method_name =
-  let class_name_mangled = Mangled.from_string class_name in
-  match resolve_method_class tenv class_name_mangled method_name with
-  | Some (Sil.TN_csu (Sil.Class, class_name)) ->
-      let class_method_name = mk_procname_from_method (Mangled.to_string class_name) method_name in
-      (try let ms = CMethod_signature.find class_method_name in
-         Some ms
-       with Not_found -> None)
-  | _ -> None
 
 let get_superclass_curr_class context =
   let retrive_super cname super_opt =

infer/src/clang/cMethod_trans.mli

@@ -27,13 +27,11 @@ val create_external_procdesc : Cfg.cfg -> Procname.t -> bool -> (Sil.typ * Sil.t
 
 val captured_vars_from_block_info : CContext.t -> Clang_ast_t.block_captured_variable list -> (Mangled.t * Sil.typ * bool) list
 
-val mk_procname_from_method : string -> string -> Procname.t
+val mk_procname_from_method : string -> string -> Procname.objc_method_kind -> Procname.t
 
 val mk_procname_from_function : string -> string -> Procname.t
 
 val get_class_selector_instance : CContext.t -> Clang_ast_t.obj_c_message_expr_info -> (Sil.exp * Sil.typ) list
   -> (string * string * method_call_type)
 
-val resolve_method : Sil.tenv -> string -> string -> CMethod_signature.method_signature option
-
 val should_create_procdesc : Cfg.cfg -> Procname.t -> bool -> bool -> bool

infer/src/clang/cTrans.ml

@@ -43,21 +43,21 @@ struct
     let (class_name, method_name, mc_type) =
       CMethod_trans.get_class_selector_instance context obj_c_message_expr_info act_params in
     let is_instance = mc_type != CMethod_trans.MCStatic in
+    let method_kind = Procname.objc_method_kind_of_bool is_instance in
     match CTrans_models.get_predefined_model_method_signature class_name method_name
             CMethod_trans.mk_procname_from_method with
     | Some ms ->
         ignore (CMethod_trans.create_local_procdesc context.cfg context.tenv ms [] [] is_instance);
         CMethod_signature.ms_get_name ms, CMethod_trans.MCNoVirtual
     | None ->
-        match CMethod_trans.resolve_method context.tenv class_name method_name with
+        let procname = CMethod_trans.mk_procname_from_method class_name method_name method_kind in
-        | Some callee_ms ->
+        try
-            (let procname = CMethod_signature.ms_get_name callee_ms in
+          let callee_ms = CMethod_signature.find procname in
           if not (M.process_getter_setter context procname) then
-               (let is_instance = is_instance || (CMethod_signature.ms_is_instance callee_ms) in
+            (ignore (CMethod_trans.create_local_procdesc context.cfg context.tenv callee_ms [] [] is_instance));
-                ignore (CMethod_trans.create_local_procdesc context.cfg context.tenv callee_ms [] [] is_instance));
+          procname, mc_type
-             procname, mc_type)
+        with Not_found ->
-        | None ->
+          let callee_pn = CMethod_trans.mk_procname_from_method class_name method_name method_kind in
-            let callee_pn = CMethod_trans.mk_procname_from_method class_name method_name in
           CMethod_trans.create_external_procdesc context.cfg callee_pn is_instance None;
           callee_pn, mc_type
 

infer/src/clang/cTrans_models.ml

@@ -121,13 +121,13 @@ let is_assert_log sil_fe =
 let is_objc_memory_model_controlled o =
   Core_foundation_model.is_objc_memory_model_controlled o
 
-let get_predefined_ms_method condition class_name method_name mk_procname
+let get_predefined_ms_method condition class_name method_name method_kind mk_procname
     arguments return_type attributes builtin =
   if condition then
     let procname =
       match builtin with
       | Some procname -> procname
-      | None -> mk_procname class_name method_name in
+      | None -> mk_procname class_name method_name method_kind in
     let ms = CMethod_signature.make_ms procname arguments return_type attributes
         (Ast_expressions.dummy_source_range ()) false false in
     Some ms
@@ -135,26 +135,27 @@ let get_predefined_ms_method condition class_name method_name mk_procname
 
 let get_predefined_ms_stringWithUTF8String class_name method_name mk_procname =
   let condition = class_name = nsstring_cl && method_name = string_with_utf8_m in
-  get_predefined_ms_method condition class_name method_name mk_procname [("x", "char *", None)]
+  get_predefined_ms_method condition class_name method_name Procname.Class_objc_method
-    id_cl [] None
+    mk_procname [("x", "char *", None)] id_cl [] None
 
 let get_predefined_ms_retain_release class_name method_name mk_procname =
   let condition = is_retain_or_release method_name in
   let return_type =
     if is_retain_method method_name || is_autorelease_method method_name
     then id_cl else void in
-  get_predefined_ms_method condition nsobject_cl method_name mk_procname
+  get_predefined_ms_method condition nsobject_cl method_name Procname.Instance_objc_method
-    [(self, class_name, None)] return_type [] (get_builtinname method_name)
+    mk_procname [(self, class_name, None)] return_type [] (get_builtinname method_name)
 
 let get_predefined_ms_autoreleasepool_init class_name method_name mk_procname =
   let condition = (method_name = init) && (class_name = nsautorelease_pool_cl) in
-  get_predefined_ms_method condition class_name method_name mk_procname
+  get_predefined_ms_method condition class_name method_name Procname.Instance_objc_method
-    [(self, class_name, None)] void [] None
+    mk_procname [(self, class_name, None)] void [] None
 
 let get_predefined_ms_nsautoreleasepool_release class_name method_name mk_procname =
   let condition = (method_name = release || method_name = drain) &&
                   (class_name = nsautorelease_pool_cl) in
-  get_predefined_ms_method condition class_name method_name mk_procname [(self, class_name, None)]
+  get_predefined_ms_method condition class_name method_name Procname.Instance_objc_method
+    mk_procname [(self, class_name, None)]
     void [] (Some SymExec.ModelBuiltins.__objc_release_autorelease_pool)
 
 let get_predefined_model_method_signature class_name method_name mk_procname =

infer/src/clang/cTrans_models.mli

@@ -25,7 +25,8 @@ val is_modeled_builtin : string -> bool
 
 val is_toll_free_bridging : Procname.t option -> bool
 
-val get_predefined_model_method_signature : string -> string -> (string -> string -> Procname.t) ->
+val get_predefined_model_method_signature : string -> string ->
+  (string -> string -> Procname.objc_method_kind -> Procname.t) ->
   CMethod_signature.method_signature option
 
 val is_dispatch_function_name : string -> (string * int) option

infer/src/clang/cTrans_utils.ml

@@ -303,7 +303,7 @@ let new_trans trans_state loc stmt_info cls_name function_type =
   let init_ret_id = Ident.create_fresh Ident.knormal in
   let is_instance = true in
   let call_flags = { Sil.cf_virtual = is_instance; Sil.cf_noreturn = false; Sil.cf_is_objc_block = false; } in
-  let pname = CMethod_trans.mk_procname_from_method cls_name CFrontend_config.init in
+  let pname = CMethod_trans.mk_procname_from_method cls_name CFrontend_config.init Procname.Instance_objc_method in
   CMethod_trans.create_external_procdesc trans_state.context.cfg pname is_instance None;
   let args = [(Sil.Var alloc_ret_id, alloc_ret_type)] in
   let init_stmt_call = Sil.Call([init_ret_id], (Sil.Const (Sil.Cfun pname)), args, loc, call_flags) in

infer/src/clang/objcProperty_decl.ml

@@ -243,15 +243,6 @@ let prepare_dynamic_property curr_class decl_info property_impl_decl_info =
       (* No names of fields/method to collect from ObjCPropertyImplDecl when Synthesized *)
       []
 
-(*NOTE: Assumption: if there is a getter or a setter defined manually, *)
-(* it has been translated already at this point. *)
-let method_exists cfg class_name name attributes =
-  let procname = CMethod_trans.mk_procname_from_method class_name name in
-  match Cfg.Procdesc.find_from_name cfg procname with
-  | Some procdesc ->
-      Cfg.Procdesc.is_defined procdesc
-  | None -> false
-
 let is_property_read_only attributes =
   list_mem (Ast_utils.property_attribute_eq) `Readonly attributes
 
@@ -374,10 +365,12 @@ let get_methods curr_class decl_list =
   let get_method decl list_methods =
     match decl with
       ObjCMethodDecl(decl_info, name_info, method_decl_info) as d ->
+        let is_instance = method_decl_info.Clang_ast_t.omdi_is_instance_method in
+        let method_kind = Procname.objc_method_kind_of_bool is_instance in
         let method_name = name_info.Clang_ast_t.ni_name in
         Printing.log_out "  ...Adding Method '%s' \n" (class_name^"_"^method_name);
         let _ = check_for_property curr_class method_name d method_decl_info.Clang_ast_t.omdi_body in
-        let meth_name = CMethod_trans.mk_procname_from_method class_name method_name in
+        let meth_name = CMethod_trans.mk_procname_from_method class_name method_name method_kind in
         meth_name:: list_methods
     | _ -> list_methods in
   list_fold_right get_method decl_list []

infer/tests/codetoanalyze/objc/errors/npe/Npe_with_equal_names.m

@@ -0,0 +1,43 @@
+/*
+* Copyright (c) 2014 - 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/NSObject.h>
+
+@interface A : NSObject {
+    @public int x;
+}
+
++(A*) meth;
+
+@property (nonatomic, readonly) A* meth;
+
+@end
+
+@implementation A
+
++(A*) meth {
+    return [A new];
+}
+
+-(A*) meth {
+    return nil;
+}
+
+@end
+
+int test() {
+    A* para = [A new];
+    A *a = [para meth];
+    return a->x;
+}
+
+int test2(A* para) {
+    A *a = [A meth];
+    return a->x;
+}

infer/tests/endtoend/objc/NPEEqualNamesTest.java

@@ -0,0 +1,68 @@
+/*
+* Copyright (c) 2013 - 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.
+*/
+
+package endtoend.objc;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static utils.matchers.ResultContainsExactly.containsExactly;
+import static utils.matchers.ResultContainsNoErrorInMethod.doesNotContain;
+import static utils.matchers.ResultContainsErrorInMethod.contains;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import utils.DebuggableTemporaryFolder;
+import utils.InferException;
+import utils.InferResults;
+import utils.InferRunner;
+
+public class NPEEqualNamesTest {
+
+  public static final String NPE_FILE =
+      "infer/tests/codetoanalyze/objc/errors/npe/Npe_with_equal_names.m";
+
+  private static ImmutableList<String> inferCmdNPD;
+
+  public static final String NULL_DEREFERENCE = "NULL_DEREFERENCE";
+
+  @ClassRule
+  public static DebuggableTemporaryFolder folderNPD = new DebuggableTemporaryFolder();
+
+  @BeforeClass
+  public static void runInfer() throws InterruptedException, IOException {
+    inferCmdNPD = InferRunner.createiOSInferCommandWithMLBuckets(
+        folderNPD,
+        NPE_FILE,
+        "cf",
+        false);
+  }
+
+  @Test
+  public void nullDereferenceTest() throws InterruptedException, IOException, InferException {
+    InferResults inferResults = InferRunner.runInferObjC(inferCmdNPD);
+    String[] procedures = {
+        "test",
+    };
+    assertThat(
+        "Results should contain null pointer dereference error",
+        inferResults,
+        containsExactly(
+            NULL_DEREFERENCE,
+            NPE_FILE,
+            procedures
+        )
+    );
+  }
+
+}