/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#include "hermes/VM/PredefinedStringIDs.h"

#include "hermes/VM/Predefined.h"

#include "hermes/VM/SymbolID.h"

#include "llvh/ADT/DenseMap.h"

#include <array>

#include <tuple>

namespace {

using namespace hermes::vm;

using StringIDMap = llvh::DenseMap<llvh::StringRef, SymbolID>;

StringIDMap createPredefinedStringSet() {

namespace P = Predefined;

auto lengths = predefStringLengths;

const size_t NumPredefStrings = P::NumStrings;

static const Predefined::Str ids[] = {

#define STR(name, string) P::name,

#include "hermes/VM/PredefinedStrings.def"

};

StringIDMap predefined;

assert(

NumPredefStrings == sizeof(ids) / sizeof(Predefined::Str) &&

"Mismatched count of predefined strings.");

const char *chars = predefStringAndSymbolChars.begin();

for (uint32_t i = 0; i < NumPredefStrings; chars += lengths[i++]) {

auto res = predefined.try_emplace(

{chars, lengths[i]}, Predefined::getSymbolID(ids[i]));

assert(res.second && "Duplicate predefined string.");

(void)res;

}

return predefined;

}

} // namespace

namespace hermes {

namespace vm {

llvh::Optional<SymbolID> getPredefinedStringID(llvh::StringRef str) {

static const auto predefined = createPredefinedStringSet();

auto it = predefined.find(str);

if (it == predefined.end()) {

return {};

}

return it->second;

}

// Use local constexpr arrays to avoid complaint about global constructors.

static constexpr uint8_t _predefStringLengths[] = {

#define STR(name, string) sizeof(string) - 1,

#include "hermes/VM/PredefinedStrings.def"

};

static constexpr uint8_t _predefSymbolLengths[] = {

#define SYM(name, symbol) sizeof(symbol) - 1,

#include "hermes/VM/PredefinedSymbols.def"

};

const llvh::ArrayRef<uint8_t> predefSymbolLengths = _predefSymbolLengths;

const llvh::ArrayRef<uint8_t> predefStringLengths = _predefStringLengths;

const llvh::ArrayRef<char> predefStringAndSymbolChars =

// One buffer contains all strings.

// This ensures that all the strings live together in memory,

// and that we don't touch multiple separate pages on startup.

#define STR(name, string) string

#include "hermes/VM/PredefinedStrings.def"

#define SYM(name, symbol) symbol

#include "hermes/VM/PredefinedSymbols.def"

;

} // namespace vm

} // namespace hermes