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Diffstat (limited to 'mojo/edk/system/options_validation.h')
-rw-r--r-- | mojo/edk/system/options_validation.h | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/mojo/edk/system/options_validation.h b/mojo/edk/system/options_validation.h deleted file mode 100644 index e1b337d..0000000 --- a/mojo/edk/system/options_validation.h +++ /dev/null @@ -1,97 +0,0 @@ -// 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. - -// Functions to help with verifying various |Mojo...Options| structs from the -// (public, C) API. These are "extensible" structs, which all have |struct_size| -// as their first member. All fields (other than |struct_size|) are optional, -// but any |flags| specified must be known to the system (otherwise, an error of -// |MOJO_RESULT_UNIMPLEMENTED| should be returned). - -#ifndef MOJO_EDK_SYSTEM_OPTIONS_VALIDATION_H_ -#define MOJO_EDK_SYSTEM_OPTIONS_VALIDATION_H_ - -#include <stddef.h> -#include <stdint.h> - -#include <algorithm> - -#include "base/logging.h" -#include "base/macros.h" -#include "mojo/edk/system/system_impl_export.h" -#include "mojo/public/c/system/types.h" - -namespace mojo { -namespace edk { - -template <class Options> -class UserOptionsReader { - public: - // Constructor from a |const* Options| (which it checks -- this constructor - // has side effects!). - // Note: We initialize |options_reader_| without checking, since we do a check - // in |GetSizeForReader()|. - explicit UserOptionsReader(const Options* options) { - CHECK(options && IsAligned<MOJO_ALIGNOF(Options)>(options)); - options_ = GetSizeForReader(options) == 0 ? nullptr : options; - static_assert(offsetof(Options, struct_size) == 0, - "struct_size not first member of Options"); - // TODO(vtl): Enable when MSVC supports this (C++11 extended sizeof): - // static_assert(sizeof(Options::struct_size) == sizeof(uint32_t), - // "Options::struct_size not a uint32_t"); - // (Or maybe assert that its type is uint32_t?) - } - - bool is_valid() const { return !!options_; } - - const Options& options() const { - DCHECK(is_valid()); - return *options_; - } - - // Checks that the given (variable-size) |options| passed to the constructor - // (plausibly) has a member at the given offset with the given size. You - // probably want to use |OPTIONS_STRUCT_HAS_MEMBER()| instead. - bool HasMember(size_t offset, size_t size) const { - DCHECK(is_valid()); - // We assume that |offset| and |size| are reasonable, since they should come - // from |offsetof(Options, some_member)| and |sizeof(Options::some_member)|, - // respectively. - return options().struct_size >= offset + size; - } - - private: - static inline size_t GetSizeForReader(const Options* options) { - uint32_t struct_size = *reinterpret_cast<const uint32_t*>(options); - if (struct_size < sizeof(uint32_t)) - return 0; - - return std::min(static_cast<size_t>(struct_size), sizeof(Options)); - } - - template <size_t alignment> - static bool IsAligned(const void* pointer) { - return reinterpret_cast<uintptr_t>(pointer) % alignment == 0; - } - - const Options* options_; - - DISALLOW_COPY_AND_ASSIGN(UserOptionsReader); -}; - -// Macro to invoke |UserOptionsReader<Options>::HasMember()| parametrized by -// member name instead of offset and size. -// -// (We can't just give |HasMember()| a member pointer template argument instead, -// since there's no good/strictly-correct way to get an offset from that.) -// -// TODO(vtl): With C++11, use |sizeof(Options::member)| instead of (the -// contortion below). We might also be able to pull out the type |Options| from -// |reader| (using |decltype|) instead of requiring a parameter. -#define OPTIONS_STRUCT_HAS_MEMBER(Options, member, reader) \ - reader.HasMember(offsetof(Options, member), sizeof(reader.options().member)) - -} // namespace edk -} // namespace mojo - -#endif // MOJO_EDK_SYSTEM_OPTIONS_VALIDATION_H_ |