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// Copyright 2017 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef COMMON_VULKANPLATFORM_H_
#define COMMON_VULKANPLATFORM_H_
#if !defined(DAWN_ENABLE_BACKEND_VULKAN)
# error "vulkan_platform.h included without the Vulkan backend enabled"
#endif
#if defined(VULKAN_CORE_H_)
# error "vulkan.h included before vulkan_platform.h"
#endif
#include "common/Platform.h"
#include <cstddef>
#include <cstdint>
// vulkan.h defines non-dispatchable handles to opaque pointers on 64bit architectures and uint64_t
// on 32bit architectures. This causes a problem in 32bit where the handles cannot be used to
// distinguish between overloads of the same function.
// Change the definition of non-dispatchable handles to be opaque structures containing a uint64_t
// and overload the comparison operators between themselves and VK_NULL_HANDLE (which will be
// redefined to be nullptr). This keeps the type-safety of having the handles be different types
// (like vulkan.h on 64 bit) but makes sure the types are different on 32 bit architectures.
#if defined(DAWN_PLATFORM_64_BIT)
# define DAWN_DEFINE_NATIVE_NON_DISPATCHABLE_HANDLE(object) using object = struct object##_T*;
// This function is needed because MSVC doesn't accept reinterpret_cast from uint64_t from uint64_t
// TODO(cwallez@chromium.org): Remove this once we rework vulkan_platform.h
template <typename T>
T NativeNonDispatachableHandleFromU64(uint64_t u64) {
return reinterpret_cast<T>(u64);
}
#elif defined(DAWN_PLATFORM_32_BIT)
# define DAWN_DEFINE_NATIVE_NON_DISPATCHABLE_HANDLE(object) using object = uint64_t;
template <typename T>
T NativeNonDispatachableHandleFromU64(uint64_t u64) {
return u64;
}
#else
# error "Unsupported platform"
#endif
// Define a dummy Vulkan handle for use before we include vulkan.h
DAWN_DEFINE_NATIVE_NON_DISPATCHABLE_HANDLE(VkSomeHandle)
// Find out the alignment of native handles. Logically we would use alignof(VkSomeHandleNative) so
// why bother with the wrapper struct? It turns out that on Linux Intel x86 alignof(uint64_t) is 8
// but alignof(struct{uint64_t a;}) is 4. This is because this Intel ABI doesn't say anything about
// double-word alignment so for historical reasons compilers violated the standard and use an
// alignment of 4 for uint64_t (and double) inside structures.
// See https://stackoverflow.com/questions/44877185
// One way to get the alignment inside structures of a type is to look at the alignment of it
// wrapped in a structure. Hence VkSameHandleNativeWrappe
namespace dawn_native { namespace vulkan {
namespace detail {
template <typename T>
struct WrapperStruct {
T member;
};
template <typename T>
static constexpr size_t AlignOfInStruct = alignof(WrapperStruct<T>);
static constexpr size_t kNativeVkHandleAlignment = AlignOfInStruct<VkSomeHandle>;
static constexpr size_t kUint64Alignment = AlignOfInStruct<uint64_t>;
// Simple handle types that supports "nullptr_t" as a 0 value.
template <typename Tag, typename HandleType>
class alignas(detail::kNativeVkHandleAlignment) VkHandle {
public:
// Default constructor and assigning of VK_NULL_HANDLE
VkHandle() = default;
VkHandle(std::nullptr_t) {
}
// Use default copy constructor/assignment
VkHandle(const VkHandle<Tag, HandleType>& other) = default;
VkHandle& operator=(const VkHandle<Tag, HandleType>&) = default;
// Comparisons between handles
bool operator==(VkHandle<Tag, HandleType> other) const {
return mHandle == other.mHandle;
}
bool operator!=(VkHandle<Tag, HandleType> other) const {
return mHandle != other.mHandle;
}
// Comparisons between handles and VK_NULL_HANDLE
bool operator==(std::nullptr_t) const {
return mHandle == 0;
}
bool operator!=(std::nullptr_t) const {
return mHandle != 0;
}
// Implicit conversion to real Vulkan types.
operator HandleType() const {
return GetHandle();
}
HandleType GetHandle() const {
return mHandle;
}
HandleType& operator*() {
return mHandle;
}
static VkHandle<Tag, HandleType> CreateFromHandle(HandleType handle) {
return VkHandle{handle};
}
private:
explicit VkHandle(HandleType handle) : mHandle(handle) {
}
HandleType mHandle = 0;
};
} // namespace detail
static constexpr std::nullptr_t VK_NULL_HANDLE = nullptr;
template <typename Tag, typename HandleType>
HandleType* AsVkArray(detail::VkHandle<Tag, HandleType>* handle) {
return reinterpret_cast<HandleType*>(handle);
}
}} // namespace dawn_native::vulkan
#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) \
DAWN_DEFINE_NATIVE_NON_DISPATCHABLE_HANDLE(object) \
namespace dawn_native { namespace vulkan { \
using object = detail::VkHandle<struct VkTag##object, ::object>; \
static_assert(sizeof(object) == sizeof(uint64_t), ""); \
static_assert(alignof(object) == detail::kUint64Alignment, ""); \
static_assert(sizeof(object) == sizeof(::object), ""); \
static_assert(alignof(object) == detail::kNativeVkHandleAlignment, ""); \
} \
} // namespace dawn_native::vulkan
// Import additional parts of Vulkan that are supported on our architecture and preemptively include
// headers that vulkan.h includes that we have "undefs" for.
#if defined(DAWN_PLATFORM_WINDOWS)
# define VK_USE_PLATFORM_WIN32_KHR
# include "common/windows_with_undefs.h"
#endif // DAWN_PLATFORM_WINDOWS
#if defined(DAWN_USE_X11)
# define VK_USE_PLATFORM_XLIB_KHR
# define VK_USE_PLATFORM_XCB_KHR
# include "common/xlib_with_undefs.h"
#endif // defined(DAWN_USE_X11)
#if defined(DAWN_ENABLE_BACKEND_METAL)
# define VK_USE_PLATFORM_METAL_EXT
#endif // defined(DAWN_ENABLE_BACKEND_METAL)
#if defined(DAWN_PLATFORM_ANDROID)
# define VK_USE_PLATFORM_ANDROID_KHR
#endif // defined(DAWN_PLATFORM_ANDROID)
#if defined(DAWN_PLATFORM_FUCHSIA)
# define VK_USE_PLATFORM_FUCHSIA
#endif // defined(DAWN_PLATFORM_FUCHSIA)
// The actual inclusion of vulkan.h!
#define VK_NO_PROTOTYPES
#include <vulkan/vulkan.h>
// Redefine VK_NULL_HANDLE for better type safety where possible.
#undef VK_NULL_HANDLE
#if defined(DAWN_PLATFORM_64_BIT)
static constexpr std::nullptr_t VK_NULL_HANDLE = nullptr;
#elif defined(DAWN_PLATFORM_32_BIT)
static constexpr uint64_t VK_NULL_HANDLE = 0;
#else
# error "Unsupported platform"
#endif
#endif // COMMON_VULKANPLATFORM_H_