1/*
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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
6
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.
11
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.
16
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/>.
19*/
20
21#include <cassert>
22#include <iostream>
23#include <sstream>
24#include <string>
25
26#include "evaluate.h"
27#include "movegen.h"
28#include "position.h"
29#include "search.h"
30#include "thread.h"
31#include "timeman.h"
32#include "tt.h"
33#include "uci.h"
34#include "syzygy/tbprobe.h"
35
36using namespace std;
37
38extern vector<string> setup_bench(const Position&, istream&);
39
40namespace {
41
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";
44
45
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").
50
51 void position(Position& pos, istringstream& is, StateListPtr& states) {
52
53 Move m;
54 string token, fen;
55
56 is >> token;
57
58 if (token == "startpos")
59 {
60 fen = StartFEN;
61 is >> token; // Consume "moves" token if any
62 }
63 else if (token == "fen")
64 while (is >> token && token != "moves")
65 fen += token + " ";
66 else
67 return;
68
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());
71
72 // Parse move list (if any)
73 while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
74 {
75 states->emplace_back();
76 pos.do_move(m, states->back());
77 }
78 }
79
80
81 // setoption() is called when engine receives the "setoption" UCI command. The
82 // function updates the UCI option ("name") to the given value ("value").
83
84 void setoption(istringstream& is) {
85
86 string token, name, value;
87
88 is >> token; // Consume "name" token
89
90 // Read option name (can contain spaces)
91 while (is >> token && token != "value")
92 name += (name.empty() ? "" : " ") + token;
93
94 // Read option value (can contain spaces)
95 while (is >> token)
96 value += (value.empty() ? "" : " ") + token;
97
98 if (Options.count(name))
99 Options[name] = value;
100 else
101 sync_cout << "No such option: " << name << sync_endl;
102 }
103
104
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
107 // the search.
108
109 void go(Position& pos, istringstream& is, StateListPtr& states) {
110
111 Search::LimitsType limits;
112 string token;
113 bool ponderMode = false;
114
115 limits.startTime = now(); // As early as possible!
116
117 while (is >> token)
118 if (token == "searchmoves")
119 while (is >> token)
120 limits.searchmoves.push_back(UCI::to_move(pos, token));
121
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;
134
135 Threads.start_thinking(pos, states, limits, ponderMode);
136 }
137
138
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.
142
143 void bench(Position& pos, istream& args, StateListPtr& states) {
144
145 string token;
146 uint64_t num, nodes = 0, cnt = 1;
147
148 vector<string> list = setup_bench(pos, args);
149 num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0; });
150
151 TimePoint elapsed = now();
152
153 for (const auto& cmd : list)
154 {
155 istringstream is(cmd);
156 is >> skipws >> token;
157
158 if (token == "go")
159 {
160 cerr << "\nPosition: " << cnt++ << '/' << num << endl;
161 go(pos, is, states);
162 Threads.main()->wait_for_search_finished();
163 nodes += Threads.nodes_searched();
164 }
165 else if (token == "setoption") setoption(is);
166 else if (token == "position") position(pos, is, states);
167 else if (token == "ucinewgame") { Search::clear(); elapsed = now(); } // Search::clear() may take some while
168 }
169
170 elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
171
172 dbg_print(); // Just before exiting
173
174 cerr << "\n==========================="
175 << "\nTotal time (ms) : " << elapsed
176 << "\nNodes searched : " << nodes
177 << "\nNodes/second : " << 1000 * nodes / elapsed << endl;
178 }
179
180} // namespace
181
182
183/// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
184/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
185/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
186/// run 'bench', once the command is executed the function returns immediately.
187/// In addition to the UCI ones, also some additional debug commands are supported.
188
189void UCI::loop(int argc, char* argv[]) {
190
191 Position pos;
192 string token, cmd;
193 StateListPtr states(new std::deque<StateInfo>(1));
194 auto uiThread = std::make_shared<Thread>(0);
195
196 pos.set(StartFEN, false, &states->back(), uiThread.get());
197
198 for (int i = 1; i < argc; ++i)
199 cmd += std::string(argv[i]) + " ";
200
201 do {
202 if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
203 cmd = "quit";
204
205 istringstream is(cmd);
206
207 token.clear(); // Avoid a stale if getline() returns empty or blank line
208 is >> skipws >> token;
209
210 if ( token == "quit"
211 || token == "stop")
212 Threads.stop = true;
213
214 // The GUI sends 'ponderhit' to tell us the user has played the expected move.
215 // So 'ponderhit' will be sent if we were told to ponder on the same move the
216 // user has played. We should continue searching but switch from pondering to
217 // normal search.
218 else if (token == "ponderhit")
219 Threads.main()->ponder = false; // Switch to normal search
220
221 else if (token == "uci")
222 sync_cout << "id name " << engine_info(true)
223 << "\n" << Options
224 << "\nuciok" << sync_endl;
225
226 else if (token == "setoption") setoption(is);
227 else if (token == "go") go(pos, is, states);
228 else if (token == "position") position(pos, is, states);
229 else if (token == "ucinewgame") Search::clear();
230 else if (token == "isready") sync_cout << "readyok" << sync_endl;
231
232 // Additional custom non-UCI commands, mainly for debugging
233 else if (token == "flip") pos.flip();
234 else if (token == "bench") bench(pos, is, states);
235 else if (token == "d") sync_cout << pos << sync_endl;
236 else if (token == "eval") sync_cout << Eval::trace(pos) << sync_endl;
237 else
238 sync_cout << "Unknown command: " << cmd << sync_endl;
239
240 } while (token != "quit" && argc == 1); // Command line args are one-shot
241}
242
243
244/// UCI::value() converts a Value to a string suitable for use with the UCI
245/// protocol specification:
246///
247/// cp <x> The score from the engine's point of view in centipawns.
248/// mate <y> Mate in y moves, not plies. If the engine is getting mated
249/// use negative values for y.
250
251string UCI::value(Value v) {
252
253 assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
254
255 stringstream ss;
256
257 if (abs(v) < VALUE_MATE - MAX_PLY)
258 ss << "cp " << v * 100 / PawnValueEg;
259 else
260 ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
261
262 return ss.str();
263}
264
265
266/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
267
268std::string UCI::square(Square s) {
269 return std::string{ char('a' + file_of(s)), char('1' + rank_of(s)) };
270}
271
272
273/// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
274/// The only special case is castling, where we print in the e1g1 notation in
275/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
276/// castling moves are always encoded as 'king captures rook'.
277
278string UCI::move(Move m, bool chess960) {
279
280 Square from = from_sq(m);
281 Square to = to_sq(m);
282
283 if (m == MOVE_NONE)
284 return "(none)";
285
286 if (m == MOVE_NULL)
287 return "0000";
288
289 if (type_of(m) == CASTLING && !chess960)
290 to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
291
292 string move = UCI::square(from) + UCI::square(to);
293
294 if (type_of(m) == PROMOTION)
295 move += " pnbrqk"[promotion_type(m)];
296
297 return move;
298}
299
300
301/// UCI::to_move() converts a string representing a move in coordinate notation
302/// (g1f3, a7a8q) to the corresponding legal Move, if any.
303
304Move UCI::to_move(const Position& pos, string& str) {
305
306 if (str.length() == 5) // Junior could send promotion piece in uppercase
307 str[4] = char(tolower(str[4]));
308
309 for (const auto& m : MoveList<LEGAL>(pos))
310 if (str == UCI::move(m, pos.is_chess960()))
311 return m;
312
313 return MOVE_NONE;
314}
315