chromium/v8/src/wasm/canonical-types.h

// Copyright 2022 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if !V8_ENABLE_WEBASSEMBLY
#error This header should only be included if WebAssembly is enabled.
#endif  // !V8_ENABLE_WEBASSEMBLY

#ifndef V8_WASM_CANONICAL_TYPES_H_
#define V8_WASM_CANONICAL_TYPES_H_

#include <unordered_map>

#include "src/base/functional.h"
#include "src/wasm/wasm-module.h"

namespace v8::internal::wasm {

// A singleton class, responsible for isorecursive canonicalization of wasm
// types.
// A recursive group is a subsequence of types explicitly marked in the type
// section of a wasm module. Identical recursive groups have to be canonicalized
// to a single canonical group. Respective types in two identical groups are
// considered identical for all purposes.
// Two groups are considered identical if they have the same shape, and all
// type indices referenced in the same position in both groups reference:
// - identical types, if those do not belong to the rec. group,
// - types in the same relative position in the group, if those belong to the
//   rec. group.
class TypeCanonicalizer { … };

// Returns a reference to the TypeCanonicalizer shared by the entire process.
V8_EXPORT_PRIVATE TypeCanonicalizer* GetTypeCanonicalizer();

}  // namespace v8::internal::wasm

#endif  // V8_WASM_CANONICAL_TYPES_H_