1 // RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=ref %s 2 // RUN: %clang_cc1 -std=c++20 -fsyntax-only -fexperimental-new-constant-interpreter -verify %s 3 4 /// This is a version of the nqueens.cpp from SemaCXX/, 5 /// but we don't initialize the State variable in the 6 /// Board constructors. 7 /// This tests that InterpFrame::describe(). 8 9 typedef unsigned long uint64_t; 10 11 struct Board { 12 uint64_t State; 13 bool Failed; 14 15 constexpr Board() : Failed(false) {} 16 constexpr Board(const Board &O) : Failed(O.Failed) {} 17 constexpr Board(uint64_t State, bool Failed = false) : 18 Failed(Failed) {} 19 constexpr Board addQueen(int Row, int Col) const { 20 return Board(State | ((uint64_t)Row << (Col * 4))); // ref-note {{read of uninitialized object}} \ 21 // expected-note {{read of uninitialized object}} 22 } 23 constexpr int getQueenRow(int Col) const { 24 return (State >> (Col * 4)) & 0xf; 25 } 26 constexpr bool ok(int Row, int Col) const { 27 return okRecurse(Row, Col, 0); 28 } 29 constexpr bool okRecurse(int Row, int Col, int CheckCol) const { 30 return Col == CheckCol ? true : 31 getQueenRow(CheckCol) == Row ? false : 32 getQueenRow(CheckCol) == Row + (Col - CheckCol) ? false : 33 getQueenRow(CheckCol) == Row + (CheckCol - Col) ? false : 34 okRecurse(Row, Col, CheckCol + 1); 35 } 36 constexpr bool at(int Row, int Col) const { 37 return getQueenRow(Col) == Row; 38 } 39 constexpr bool check(const char *, int=0, int=0) const; 40 }; 41 42 constexpr Board buildBoardRecurse(int N, int Col, const Board &B); 43 constexpr Board buildBoardScan(int N, int Col, int Row, const Board &B); 44 constexpr Board tryBoard(const Board &Try, 45 int N, int Col, int Row, const Board &B) { 46 return Try.Failed ? buildBoardScan(N, Col, Row, B) : Try; 47 } 48 constexpr Board buildBoardScan(int N, int Col, int Row, const Board &B) { 49 return Row == N ? Board(0, true) : 50 B.ok(Row, Col) ? 51 tryBoard(buildBoardRecurse(N, Col + 1, B.addQueen(Row, Col)), // ref-note {{in call to 'B.addQueen(0, 0)}} \ 52 // expected-note {{in call to 'B.addQueen(0, 0)}} 53 N, Col, Row+1, B) : 54 buildBoardScan(N, Col, Row + 1, B); 55 } 56 constexpr Board buildBoardRecurse(int N, int Col, const Board &B) { 57 return Col == N ? B : buildBoardScan(N, Col, 0, B); // ref-note {{in call to 'buildBoardScan(8, 0, 0, Board())'}} \ 58 // expected-note {{in call to 'buildBoardScan(8, 0, 0, Board())'}} 59 60 } 61 constexpr Board buildBoard(int N) { 62 return buildBoardRecurse(N, 0, Board()); // ref-note {{in call to 'buildBoardRecurse(8, 0, Board())'}} \ 63 // expected-note {{in call to 'buildBoardRecurse(8, 0, Board())'}} 64 } 65 66 constexpr Board q8 = buildBoard(8); // ref-error {{must be initialized by a constant expression}} \ 67 // ref-note {{in call to 'buildBoard(8)'}} \ 68 // expected-error {{must be initialized by a constant expression}} \ 69 // expected-note {{in call to 'buildBoard(8)'}} 70