chromium/third_party/dawn/src/tint/utils/id/generation_id.h

// Copyright 2021 The Dawn & Tint Authors
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#ifndef SRC_TINT_UTILS_ID_GENERATION_ID_H_
#define SRC_TINT_UTILS_ID_GENERATION_ID_H_

#include <stdint.h>
#include <utility>

#include "src/tint/utils/ice/ice.h"
#include "src/tint/utils/text/string_stream.h"
#include "src/tint/utils/traits/traits.h"

namespace tint {

/// If 1 then checks are enabled that AST nodes are not leaked from one generation to another.
/// It may be worth disabling this in production builds. For now we always check.
#define TINT_CHECK_FOR_CROSS_GENERATION_LEAKS …

/// A GenerationID is a unique identifier of a generation.
/// GenerationID can be used to ensure that objects referenced by the generation are
/// owned exclusively by that generation and have accidentally not leaked from
/// another generation.
class GenerationID { … };

/// A simple pass-through function for GenerationID. Intended to be overloaded for
/// other types.
/// @param id a GenerationID
/// @returns id. Simple pass-through function
inline GenerationID GenerationIDOf(GenerationID id) { … }

/// Writes the GenerationID to the stream.
/// @param out the stream to write to
/// @param id the generation identifier to write
/// @returns out so calls can be chained
template <typename STREAM, typename = traits::EnableIfIsOStream<STREAM>>
auto& operator<<(STREAM& out, GenerationID id) { … }

namespace detail {

/// AssertGenerationIDsEqual is called by TINT_ASSERT_GENERATION_IDS_EQUAL() and
/// TINT_ASSERT_GENERATION_IDS_EQUAL_IF_VALID() to assert that the GenerationIDs
/// `a` and `b` are equal.
void AssertGenerationIDsEqual(GenerationID a,
                              GenerationID b,
                              bool if_valid,
                              const char* msg,
                              const char* file,
                              size_t line);

}  // namespace detail

/// TINT_ASSERT_GENERATION_IDS_EQUAL(A, B) is a macro that asserts that the
/// generation identifiers for A and B are equal.
///
/// TINT_ASSERT_GENERATION_IDS_EQUAL_IF_VALID(A, B) is a macro that asserts
/// that the generation identifiers for A and B are equal, if both A and B have
/// valid generation identifiers.
#if TINT_CHECK_FOR_CROSS_GENERATION_LEAKS
#define TINT_ASSERT_GENERATION_IDS_EQUAL(a, b) …
#define TINT_ASSERT_GENERATION_IDS_EQUAL_IF_VALID(a, b) …
#else
#define TINT_ASSERT_GENERATION_IDS_EQUAL …
#define TINT_ASSERT_GENERATION_IDS_EQUAL_IF_VALID …
#endif

}  // namespace tint

#endif  // SRC_TINT_UTILS_ID_GENERATION_ID_H_