mojo/system/memory.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MOJO_SYSTEM_MEMORY_H_
   6 #define MOJO_SYSTEM_MEMORY_H_
   7
   8 #include <stddef.h>
   9
  10 #include "mojo/public/c/system/macros.h"
  11 #include "mojo/system/system_impl_export.h"
  12
  13 namespace mojo {
  14 namespace system {
  15
  16 namespace internal {
  17
  18 template <size_t size, size_t alignment>
  19 bool MOJO_SYSTEM_IMPL_EXPORT VerifyUserPointerHelper(const void* pointer);
  20
  21 // Note: This is also used by options_validation.h.
  22 template <size_t size, size_t alignment>
  23 bool MOJO_SYSTEM_IMPL_EXPORT VerifyUserPointerWithCountHelper(
  24     const void* pointer,
  25     size_t count);
  26
  27 }  // namespace internal
  28
  29 // Verify (insofar as possible/necessary) that a |T| can be read from the user
  30 // |pointer|.
  31 template <typename T>
  32 bool VerifyUserPointer(const T* pointer) {
  33   return internal::VerifyUserPointerHelper<sizeof(T), MOJO_ALIGNOF(T)>(pointer);
  34 }
  35
  36 // Verify (insofar as possible/necessary) that |count| |T|s can be read from the
  37 // user |pointer|; |count| may be zero. (This is done carefully since |count *
  38 // sizeof(T)| may overflow a |size_t|.)
  39 template <typename T>
  40 bool VerifyUserPointerWithCount(const T* pointer, size_t count) {
  41   return internal::VerifyUserPointerWithCountHelper<sizeof(T),
  42                                                     MOJO_ALIGNOF(T)>(pointer,
  43                                                                      count);
  44 }
  45
  46 // Verify that |size| bytes (which may be zero) can be read from the user
  47 // |pointer|, and that |pointer| has the specified |alignment| (if |size| is
  48 // nonzero).
  49 template <size_t alignment>
  50 bool MOJO_SYSTEM_IMPL_EXPORT VerifyUserPointerWithSize(const void* pointer,
  51                                                        size_t size);
  52
  53 }  // namespace system
  54 }  // namespace mojo
  55
  56 #endif  // MOJO_SYSTEM_MEMORY_H_