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nudt-compiler-cpp/third_party/antlr4-runtime-4.13.2/runtime/src/atn/LexerActionExecutor.cpp

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C++
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/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
#include "misc/MurmurHash.h"
#include "atn/LexerIndexedCustomAction.h"
#include "atn/HashUtils.h"
#include "support/CPPUtils.h"
#include "support/Arrays.h"
#include "support/Casts.h"
#include "atn/LexerActionExecutor.h"
using namespace antlr4;
using namespace antlr4::atn;
using namespace antlr4::misc;
using namespace antlrcpp;
namespace {
bool lexerActionEqual(const Ref<const LexerAction> &lhs, const Ref<const LexerAction> &rhs) {
return *lhs == *rhs;
}
}
LexerActionExecutor::LexerActionExecutor(std::vector<Ref<const LexerAction>> lexerActions)
: _lexerActions(std::move(lexerActions)), _hashCode(0) {}
Ref<const LexerActionExecutor> LexerActionExecutor::append(const Ref<const LexerActionExecutor> &lexerActionExecutor,
Ref<const LexerAction> lexerAction) {
if (lexerActionExecutor == nullptr) {
return std::make_shared<LexerActionExecutor>(std::vector<Ref<const LexerAction>>{ std::move(lexerAction) });
}
std::vector<Ref<const LexerAction>> lexerActions;
lexerActions.reserve(lexerActionExecutor->_lexerActions.size() + 1);
lexerActions.insert(lexerActions.begin(), lexerActionExecutor->_lexerActions.begin(), lexerActionExecutor->_lexerActions.end());
lexerActions.push_back(std::move(lexerAction));
return std::make_shared<LexerActionExecutor>(std::move(lexerActions));
}
Ref<const LexerActionExecutor> LexerActionExecutor::fixOffsetBeforeMatch(int offset) const {
std::vector<Ref<const LexerAction>> updatedLexerActions;
for (size_t i = 0; i < _lexerActions.size(); i++) {
if (_lexerActions[i]->isPositionDependent() && !LexerIndexedCustomAction::is(*_lexerActions[i])) {
if (updatedLexerActions.empty()) {
updatedLexerActions = _lexerActions; // Make a copy.
}
updatedLexerActions[i] = std::make_shared<LexerIndexedCustomAction>(offset, _lexerActions[i]);
}
}
if (updatedLexerActions.empty()) {
return shared_from_this();
}
return std::make_shared<LexerActionExecutor>(std::move(updatedLexerActions));
}
const std::vector<Ref<const LexerAction>>& LexerActionExecutor::getLexerActions() const {
return _lexerActions;
}
void LexerActionExecutor::execute(Lexer *lexer, CharStream *input, size_t startIndex) const {
bool requiresSeek = false;
size_t stopIndex = input->index();
auto onExit = finally([requiresSeek, input, stopIndex]() {
if (requiresSeek) {
input->seek(stopIndex);
}
});
for (const auto &lexerAction : _lexerActions) {
if (LexerIndexedCustomAction::is(*lexerAction)) {
int offset = downCast<const LexerIndexedCustomAction&>(*lexerAction).getOffset();
input->seek(startIndex + offset);
requiresSeek = (startIndex + offset) != stopIndex;
} else if (lexerAction->isPositionDependent()) {
input->seek(stopIndex);
requiresSeek = false;
}
lexerAction->execute(lexer);
}
}
size_t LexerActionExecutor::hashCode() const {
auto hash = _hashCode.load(std::memory_order_relaxed);
if (hash == 0) {
hash = MurmurHash::initialize();
for (const auto &lexerAction : _lexerActions) {
hash = MurmurHash::update(hash, lexerAction);
}
hash = MurmurHash::finish(hash, _lexerActions.size());
if (hash == 0) {
hash = std::numeric_limits<size_t>::max();
}
_hashCode.store(hash, std::memory_order_relaxed);
}
return hash;
}
bool LexerActionExecutor::equals(const LexerActionExecutor &other) const {
if (this == std::addressof(other)) {
return true;
}
return cachedHashCodeEqual(_hashCode.load(std::memory_order_relaxed), other._hashCode.load(std::memory_order_relaxed)) &&
_lexerActions.size() == other._lexerActions.size() &&
std::equal(_lexerActions.begin(), _lexerActions.end(), other._lexerActions.begin(), lexerActionEqual);
}