2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
5 Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
7 Stockfish is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 Stockfish is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
34 #include "syzygy/tbprobe.h"
38 extern vector<string> setup_bench(const Position&, istream&);
42 // FEN string of the initial position, normal chess
43 const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
46 // position() is called when engine receives the "position" UCI command.
47 // The function sets up the position described in the given FEN string ("fen")
48 // or the starting position ("startpos") and then makes the moves given in the
49 // following move list ("moves").
51 void position(Position& pos, istringstream& is, StateListPtr& states) {
58 if (token == "startpos")
61 is >> token; // Consume "moves" token if any
63 else if (token == "fen")
64 while (is >> token && token != "moves")
69 states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
70 pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
72 // Parse move list (if any)
73 while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
75 states->emplace_back();
76 pos.do_move(m, states->back());
81 // setoption() is called when engine receives the "setoption" UCI command. The
82 // function updates the UCI option ("name") to the given value ("value").
84 void setoption(istringstream& is) {
86 string token, name, value;
88 is >> token; // Consume "name" token
90 // Read option name (can contain spaces)
91 while (is >> token && token != "value")
92 name += (name.empty() ? "" : " ") + token;
94 // Read option value (can contain spaces)
96 value += (value.empty() ? "" : " ") + token;
98 if (Options.count(name))
99 Options[name] = value;
101 sync_cout << "No such option: " << name << sync_endl;
105 // go() is called when engine receives the "go" UCI command. The function sets
106 // the thinking time and other parameters from the input string, then starts
109 void go(Position& pos, istringstream& is, StateListPtr& states) {
111 Search::LimitsType limits;
113 bool ponderMode = false;
115 limits.startTime = now(); // As early as possible!
118 if (token == "searchmoves")
120 limits.searchmoves.push_back(UCI::to_move(pos, token));
122 else if (token == "wtime") is >> limits.time[WHITE];
123 else if (token == "btime") is >> limits.time[BLACK];
124 else if (token == "winc") is >> limits.inc[WHITE];
125 else if (token == "binc") is >> limits.inc[BLACK];
126 else if (token == "movestogo") is >> limits.movestogo;
127 else if (token == "depth") is >> limits.depth;
128 else if (token == "nodes") is >> limits.nodes;
129 else if (token == "movetime") is >> limits.movetime;
130 else if (token == "mate") is >> limits.mate;
131 else if (token == "perft") is >> limits.perft;
132 else if (token == "infinite") limits.infinite = 1;
133 else if (token == "ponder") ponderMode = true;
135 Threads.start_thinking(pos, states, limits, ponderMode);
139 // bench() is called when engine receives the "bench" command. Firstly
140 // a list of UCI commands is setup according to bench parameters, then
141 // it is run one by one printing a summary at the end.
143 void bench(Position& pos, istream& args, StateListPtr& states) {
146 uint64_t num, nodes = 0, cnt = 1;
148 vector<string> list = setup_bench(pos, args);
149 num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0 || s.find("eval") == 0; });
151 TimePoint elapsed = now();
153 for (const auto& cmd : list)
155 istringstream is(cmd);
156 is >> skipws >> token;
158 if (token == "go" || token == "eval")
160 cerr << "\nPosition: " << cnt++ << '/' << num << endl;
164 Threads.main()->wait_for_search_finished();
165 nodes += Threads.nodes_searched();
168 sync_cout << "\n" << Eval::trace(pos) << sync_endl;
170 else if (token == "setoption") setoption(is);
171 else if (token == "position") position(pos, is, states);
172 else if (token == "ucinewgame") { Search::clear(); elapsed = now(); } // Search::clear() may take some while
175 elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
177 dbg_print(); // Just before exiting
179 cerr << "\n==========================="
180 << "\nTotal time (ms) : " << elapsed
181 << "\nNodes searched : " << nodes
182 << "\nNodes/second : " << 1000 * nodes / elapsed << endl;
188 /// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
189 /// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
190 /// GUI dies unexpectedly. When called with some command line arguments, e.g. to
191 /// run 'bench', once the command is executed the function returns immediately.
192 /// In addition to the UCI ones, also some additional debug commands are supported.
194 void UCI::loop(int argc, char* argv[]) {
198 StateListPtr states(new std::deque<StateInfo>(1));
200 pos.set(StartFEN, false, &states->back(), Threads.main());
202 for (int i = 1; i < argc; ++i)
203 cmd += std::string(argv[i]) + " ";
206 if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
209 istringstream is(cmd);
211 token.clear(); // Avoid a stale if getline() returns empty or blank line
212 is >> skipws >> token;
218 // The GUI sends 'ponderhit' to tell us the user has played the expected move.
219 // So 'ponderhit' will be sent if we were told to ponder on the same move the
220 // user has played. We should continue searching but switch from pondering to
222 else if (token == "ponderhit")
223 Threads.main()->ponder = false; // Switch to normal search
225 else if (token == "uci")
226 sync_cout << "id name " << engine_info(true)
228 << "\nuciok" << sync_endl;
230 else if (token == "setoption") setoption(is);
231 else if (token == "go") go(pos, is, states);
232 else if (token == "position") position(pos, is, states);
233 else if (token == "ucinewgame") Search::clear();
234 else if (token == "isready") sync_cout << "readyok" << sync_endl;
236 // Additional custom non-UCI commands, mainly for debugging.
237 // Do not use these commands during a search!
238 else if (token == "flip") pos.flip();
239 else if (token == "bench") bench(pos, is, states);
240 else if (token == "d") sync_cout << pos << sync_endl;
241 else if (token == "eval") sync_cout << Eval::trace(pos) << sync_endl;
242 else if (token == "compiler") sync_cout << compiler_info() << sync_endl;
244 sync_cout << "Unknown command: " << cmd << sync_endl;
246 } while (token != "quit" && argc == 1); // Command line args are one-shot
250 /// UCI::value() converts a Value to a string suitable for use with the UCI
251 /// protocol specification:
253 /// cp <x> The score from the engine's point of view in centipawns.
254 /// mate <y> Mate in y moves, not plies. If the engine is getting mated
255 /// use negative values for y.
257 string UCI::value(Value v) {
259 assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
263 if (abs(v) < VALUE_MATE - MAX_PLY)
264 ss << "cp " << v * 100 / PawnValueEg;
266 ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
272 /// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
274 std::string UCI::square(Square s) {
275 return std::string{ char('a' + file_of(s)), char('1' + rank_of(s)) };
279 /// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
280 /// The only special case is castling, where we print in the e1g1 notation in
281 /// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
282 /// castling moves are always encoded as 'king captures rook'.
284 string UCI::move(Move m, bool chess960) {
286 Square from = from_sq(m);
287 Square to = to_sq(m);
295 if (type_of(m) == CASTLING && !chess960)
296 to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
298 string move = UCI::square(from) + UCI::square(to);
300 if (type_of(m) == PROMOTION)
301 move += " pnbrqk"[promotion_type(m)];
307 /// UCI::to_move() converts a string representing a move in coordinate notation
308 /// (g1f3, a7a8q) to the corresponding legal Move, if any.
310 Move UCI::to_move(const Position& pos, string& str) {
312 if (str.length() == 5) // Junior could send promotion piece in uppercase
313 str[4] = char(tolower(str[4]));
315 for (const auto& m : MoveList<LEGAL>(pos))
316 if (str == UCI::move(m, pos.is_chess960()))