Validate map keys in C++ Mojo bindings

mojo/public/cpp/bindings/lib/map_data_internal.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_MAP_DATA_INTERNAL_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_MAP_DATA_INTERNAL_H_
 
 #include "mojo/public/cpp/bindings/lib/array_internal.h"
 #include "mojo/public/cpp/bindings/lib/validate_params.h"
 #include "mojo/public/cpp/bindings/lib/validation_errors.h"
 #include "mojo/public/cpp/bindings/lib/validation_util.h"
 
 namespace mojo {
 namespace internal {
 
-inline const ArrayValidateParams* GetMapKeyValidateParamsDefault() {
-  // The memory allocated here never gets released to not cause an exit time
-  // destructor.
-  static const ArrayValidateParams* validate_params =
-      new ArrayValidateParams(0, false, nullptr);
-  return validate_params;
-}
-
-inline const ArrayValidateParams* GetMapKeyValidateParamsForStrings() {
-  // The memory allocated here never gets released to not cause an exit time
-  // destructor.
-  static const ArrayValidateParams* validate_params = new ArrayValidateParams(
-      0, false, new ArrayValidateParams(0, false, nullptr));
-  return validate_params;
-}
-
-template <typename MapKey>
-struct MapKeyValidateParamsFactory {
-  static const ArrayValidateParams* Get() {
-    return GetMapKeyValidateParamsDefault();
-  }
-};
-
-// For non-nullable strings only. (Which is OK; map keys can't be null.)
-template <>
-struct MapKeyValidateParamsFactory<mojo::internal::Array_Data<char>*> {
-  static const ArrayValidateParams* Get() {
-    return GetMapKeyValidateParamsForStrings();
-  }
-};
-
 // Map serializes into a struct which has two arrays as struct fields, the keys
 // and the values.
 template <typename Key, typename Value>
 class Map_Data {
  public:
   static Map_Data* New(Buffer* buf) {
     return new (buf->Allocate(sizeof(Map_Data))) Map_Data();
   }
 
+  // |validate_params| must have non-null |key_validate_params| and
+  // |element_validate_params| members.
   static bool Validate(const void* data,
                        BoundsChecker* bounds_checker,
-                       const ArrayValidateParams* value_validate_params) {
+                       const ArrayValidateParams* validate_params) {
     if (!data)
       return true;
 
     if (!ValidateStructHeaderAndClaimMemory(data, bounds_checker))
       return false;
 
     const Map_Data* object = static_cast<const Map_Data*>(data);
     if (object->header_.num_bytes != sizeof(Map_Data) ||
         object->header_.version != 0) {
       ReportValidationError(VALIDATION_ERROR_UNEXPECTED_STRUCT_HEADER);
       return false;
     }
 
     if (!ValidateEncodedPointer(&object->keys.offset)) {
       ReportValidationError(VALIDATION_ERROR_ILLEGAL_POINTER);
       return false;
     }
     if (!object->keys.offset) {
       ReportValidationError(VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
                             "null key array in map struct");
       return false;
     }
-    const ArrayValidateParams* key_validate_params =
-        MapKeyValidateParamsFactory<Key>::Get();
     if (!Array_Data<Key>::Validate(DecodePointerRaw(&object->keys.offset),
-                                   bounds_checker, key_validate_params)) {
+                                   bounds_checker,
+                                   validate_params->key_validate_params)) {
       return false;
     }
 
     if (!ValidateEncodedPointer(&object->values.offset)) {
       ReportValidationError(VALIDATION_ERROR_ILLEGAL_POINTER);
       return false;
     }
     if (!object->values.offset) {
       ReportValidationError(VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
                             "null value array in map struct");
       return false;
     }
-    if (!Array_Data<Value>::Validate(DecodePointerRaw(&object->values.offset),
-                                     bounds_checker, value_validate_params)) {
+    if (!Array_Data<Value>::Validate(
+            DecodePointerRaw(&object->values.offset),
+            bounds_checker, validate_params->element_validate_params)) {
       return false;
     }
 
     const ArrayHeader* key_header =
         static_cast<const ArrayHeader*>(DecodePointerRaw(&object->keys.offset));
     const ArrayHeader* value_header = static_cast<const ArrayHeader*>(
         DecodePointerRaw(&object->values.offset));
     if (key_header->num_elements != value_header->num_elements) {
       ReportValidationError(VALIDATION_ERROR_DIFFERENT_SIZED_ARRAYS_IN_MAP);
       return false;
@@ skipping 23 matching lines @@
     header_.version = 0;
   }
   ~Map_Data() = delete;
 };
 static_assert(sizeof(Map_Data<char, char>) == 24, "Bad sizeof(Map_Data)");
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_MAP_DATA_INTERNAL_H_