Model init method in NSData and understand the field bytes

Reviewed By: sblackshear

Differential Revision: D3627970

fbshipit-source-id: f70d913

infer/models/objc/src/NSData.m

@@ -40,6 +40,13 @@ NSData* __objc_alloc(NSData*);
     return nil;
 }
 
+- (instancetype)initWithBytesNoCopy:(void*)bytes
+                             length:(NSUInteger)length
+                       freeWhenDone:(BOOL)flag {
+  self->_bytes = bytes;
+  return self;
+}
+
 - (void)dealloc {
   if (self)
     free(self->_bytes);

infer/src/clang/cField_decl.ml

@@ -92,3 +92,15 @@ let add_missing_fields tenv class_name ck fields =
       Printing.log_out " Updating info for class '%s' in tenv\n" class_name;
       Tenv.add tenv class_tn_name class_type_info
   | _ -> ()
+
+let modelled_fields_in_classes = [("NSData", "_bytes", Typ.Tptr (Typ.Tvoid, Typ.Pk_pointer))]
+
+let modelled_field class_name_info =
+  let modelled_field_in_class res (class_name, field_name, typ) =
+    if class_name = class_name_info.Clang_ast_t.ni_name then
+      let class_name_qualified = class_name_info.Clang_ast_t.ni_qual_name in
+      let field_name_qualified = Ast_utils.make_qual_name_decl class_name_qualified field_name in
+      let name = General_utils.mk_class_field_name field_name_qualified in
+      (name, typ, Typ.item_annotation_empty) :: res
+    else res in
+  IList.fold_left modelled_field_in_class [] modelled_fields_in_classes

infer/src/clang/cField_decl.mli

@@ -24,3 +24,5 @@ val build_sil_field : Ast_utils.type_ptr_to_sil_type -> Tenv.t -> Clang_ast_t.na
   Clang_ast_t.type_ptr -> Clang_ast_t.property_attribute list -> field_type
 
 val add_missing_fields : Tenv.t -> string -> Csu.class_kind -> field_type list -> unit
+
+val modelled_field : Clang_ast_t.named_decl_info -> field_type list

infer/src/clang/objcInterface_decl.ml

@@ -98,7 +98,8 @@ let create_superclasses_fields type_ptr_to_sil_type tenv curr_class decl_list
   superclasses, fields
 
 (* Adds pairs (interface name, interface_type_info) to the global environment. *)
-let add_class_to_tenv type_ptr_to_sil_type tenv curr_class decl_info class_name decl_list ocidi =
+let add_class_to_tenv type_ptr_to_sil_type tenv curr_class decl_info name_info decl_list ocidi =
+  let class_name = Ast_utils.get_qualified_name name_info in
   Printing.log_out "ADDING: ObjCInterfaceDecl for '%s'\n" class_name;
   let interface_name = CTypes.mk_classname class_name Csu.Objc in
   let decl_key = `DeclPtr decl_info.Clang_ast_t.di_pointer in
@@ -122,13 +123,14 @@ let add_class_to_tenv type_ptr_to_sil_type tenv curr_class decl_info class_name
     | _ -> fields, superclasses, methods in
   let fields = General_utils.append_no_duplicates_fields fields fields_sc in
   (* We add the special hidden counter_field for implementing reference counting *)
-  let fields = General_utils.append_no_duplicates_fields [Typ.objc_ref_counter_field] fields in
+  let modelled_fields = Typ.objc_ref_counter_field :: CField_decl.modelled_field name_info in
+  let all_fields = General_utils.append_no_duplicates_fields modelled_fields fields in
   Printing.log_out "Class %s field:\n" class_name;
   IList.iter (fun (fn, _, _) ->
-      Printing.log_out "-----> field: '%s'\n" (Ident.fieldname_to_string fn)) fields;
+      Printing.log_out "-----> field: '%s'\n" (Ident.fieldname_to_string fn)) all_fields;
   let interface_type_info =
     {
-      Typ.instance_fields = fields;
+      Typ.instance_fields = all_fields;
       static_fields = [];
       csu = Csu.Class Csu.Objc;
       struct_name = Some (Mangled.from_string class_name);
@@ -170,8 +172,8 @@ let interface_declaration type_ptr_to_sil_type tenv decl =
   | ObjCInterfaceDecl (decl_info, name_info, decl_list, _, ocidi) ->
       let name = Ast_utils.get_qualified_name name_info in
       let curr_class = get_curr_class name ocidi in
-      let typ =
-        add_class_to_tenv type_ptr_to_sil_type tenv curr_class decl_info name decl_list ocidi in
+      let typ = add_class_to_tenv type_ptr_to_sil_type tenv curr_class decl_info name_info
+          decl_list ocidi in
       let _ = add_class_implementation type_ptr_to_sil_type tenv ocidi in
       let _ = add_super_class_decl type_ptr_to_sil_type tenv ocidi in
       let _ = add_protocols_decl type_ptr_to_sil_type tenv ocidi.Clang_ast_t.otdi_protocols in

infer/tests/codetoanalyze/objc/errors/memory_leaks_benchmark/NSStringInitWithBytesNoCopyExample.m

@@ -16,17 +16,18 @@
 
 @implementation A
 
-NSString* FBCreateURLQueryStringBodyEscaping(NSDictionary* parameters,
-                                             NSString* s) {
+NSString* createURLQueryStringBodyEscaping(NSDictionary* parameters,
+                                           NSString* s) {
+  NSString* resultString;
   if (s) {
     char* resultBuffer = (char*)malloc(5 * sizeof(char));
 
-    NSString* resultString = [s initWithBytesNoCopy:resultBuffer
-                                             length:5
-                                           encoding:NSUTF8StringEncoding
-                                       freeWhenDone:YES];
+    resultString = [s initWithBytesNoCopy:resultBuffer
+                                   length:5
+                                 encoding:NSUTF8StringEncoding
+                             freeWhenDone:YES];
   }
-  return s;
+  return resultString;
 }
 
 + (NSData*)randomBytes:(NSUInteger)numOfBytes {
@@ -40,6 +41,15 @@ NSString* FBCreateURLQueryStringBodyEscaping(NSDictionary* parameters,
   }
 }
 
+- (NSData*)readDataOfLength:(NSUInteger)length {
+  size_t bytesLength = length;
+  void* bytes = malloc(bytesLength);
+  if (bytes == NULL) {
+    return nil;
+  }
+  return [[NSData alloc] initWithBytesNoCopy:bytes length:5 freeWhenDone:YES];
+}
+
 - (NSData*)macForIV:(NSData*)IV {
   uint8_t* result = malloc(10);
   return [NSData dataWithBytesNoCopy:result length:10];

infer/tests/endtoend/objc/infer/MemoryLeaksFromModelsTest.java

@@ -10,8 +10,7 @@
 package endtoend.objc.infer;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static utils.matchers.ResultContainsErrorInMethod.contains;
-import static utils.matchers.ResultContainsNoErrorInMethod.doesNotContain;
+import static utils.matchers.ResultContainsExactly.containsExactly;
 
 import com.google.common.collect.ImmutableList;
 
@@ -50,57 +49,18 @@ public class MemoryLeaksFromModelsTest {
   }
 
   @Test
-  public void whenInferRunsOnFBCreateURLQueryStringBodyEscapingThenMLIsNotFound()
-      throws InterruptedException, IOException, InferException {
-    InferResults inferResults = InferRunner.runInferObjC(inferCmd);
-    assertThat(
-        "Results should not contain memory leak",
-        inferResults,
-        doesNotContain(
-            MEMORY_LEAK,
-            memory_leak_file,
-            "FBCreateURLQueryStringBodyEscaping"));
-  }
-
-  @Test
-  public void whenInferRunsOnRandomBytesThenMLIsNotFound()
-      throws InterruptedException, IOException, InferException {
-    InferResults inferResults = InferRunner.runInferObjC(inferCmd);
-    assertThat(
-        "Results should not contain memory leak",
-        inferResults,
-        doesNotContain(
-            MEMORY_LEAK,
-            memory_leak_file,
-            "randomBytes:"));
-  }
-
-  @Test
-  public void whenInferRunsOn_macForIVThenMLIsFound()
-      throws InterruptedException, IOException, InferException {
-    InferResults inferResults = InferRunner.runInferObjC(inferCmd);
-    assertThat(
-        "Results should contain memory leak",
-        inferResults,
-        contains(
-            MEMORY_LEAK,
-            memory_leak_file,
-            "macForIV:"
-        )
-    );
-  }
-
-  @Test
-  public void whenInferRunsOnHexStringValueThenMLIsNotFound()
-      throws InterruptedException, IOException, InferException {
-    InferResults inferResults = InferRunner.runInferObjC(inferCmd);
-    assertThat(
-        "Results should not contain memory leak",
-        inferResults,
-        doesNotContain(
-            MEMORY_LEAK,
-            memory_leak_file,
-            "hexStringValue"));
-  }
-
+public void matchErrors()
+    throws InterruptedException, IOException, InferException {
+  InferResults inferResults = InferRunner.runInferObjC(inferCmd);
+  String[] procedures = {"macForIV:"};
+  assertThat(
+      "Results should contain the expected memory leak",
+      inferResults,
+      containsExactly(
+          MEMORY_LEAK,
+          memory_leak_file,
+          procedures
+      )
+  );
+}
 }