| // RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify=ref %s |
| // RUN: %clang_cc1 -std=c++20 -fsyntax-only -fexperimental-new-constant-interpreter -verify %s |
| |
| /// This is a version of the nqueens.cpp from SemaCXX/, |
| /// but we don't initialize the State variable in the |
| /// Board constructors. |
| /// This tests that InterpFrame::describe(). |
| |
| typedef unsigned long uint64_t; |
| |
| struct Board { |
| uint64_t State; |
| bool Failed; |
| |
| constexpr Board() : Failed(false) {} |
| constexpr Board(const Board &O) : Failed(O.Failed) {} |
| constexpr Board(uint64_t State, bool Failed = false) : |
| Failed(Failed) {} |
| constexpr Board addQueen(int Row, int Col) const { |
| return Board(State | ((uint64_t)Row << (Col * 4))); // ref-note {{read of uninitialized object}} \ |
| // expected-note {{read of object outside its lifetime}} |
| } |
| constexpr int getQueenRow(int Col) const { |
| return (State >> (Col * 4)) & 0xf; |
| } |
| constexpr bool ok(int Row, int Col) const { |
| return okRecurse(Row, Col, 0); |
| } |
| constexpr bool okRecurse(int Row, int Col, int CheckCol) const { |
| return Col == CheckCol ? true : |
| getQueenRow(CheckCol) == Row ? false : |
| getQueenRow(CheckCol) == Row + (Col - CheckCol) ? false : |
| getQueenRow(CheckCol) == Row + (CheckCol - Col) ? false : |
| okRecurse(Row, Col, CheckCol + 1); |
| } |
| constexpr bool at(int Row, int Col) const { |
| return getQueenRow(Col) == Row; |
| } |
| constexpr bool check(const char *, int=0, int=0) const; |
| }; |
| |
| constexpr Board buildBoardRecurse(int N, int Col, const Board &B); |
| constexpr Board buildBoardScan(int N, int Col, int Row, const Board &B); |
| constexpr Board tryBoard(const Board &Try, |
| int N, int Col, int Row, const Board &B) { |
| return Try.Failed ? buildBoardScan(N, Col, Row, B) : Try; |
| } |
| constexpr Board buildBoardScan(int N, int Col, int Row, const Board &B) { |
| return Row == N ? Board(0, true) : |
| B.ok(Row, Col) ? |
| tryBoard(buildBoardRecurse(N, Col + 1, B.addQueen(Row, Col)), // ref-note {{in call to '&Board()->addQueen(0, 0)}} \ |
| // expected-note {{in call to '&Board()->addQueen(0, 0)}} |
| N, Col, Row+1, B) : |
| buildBoardScan(N, Col, Row + 1, B); |
| } |
| constexpr Board buildBoardRecurse(int N, int Col, const Board &B) { |
| return Col == N ? B : buildBoardScan(N, Col, 0, B); // ref-note {{in call to 'buildBoardScan(8, 0, 0, Board())'}} \ |
| // expected-note {{in call to 'buildBoardScan(8, 0, 0, Board())'}} |
| |
| } |
| constexpr Board buildBoard(int N) { |
| return buildBoardRecurse(N, 0, Board()); // ref-note {{in call to 'buildBoardRecurse(8, 0, Board())'}} \ |
| // expected-note {{in call to 'buildBoardRecurse(8, 0, Board())'}} |
| } |
| |
| constexpr Board q8 = buildBoard(8); // ref-error {{must be initialized by a constant expression}} \ |
| // ref-note {{in call to 'buildBoard(8)'}} \ |
| // expected-error {{must be initialized by a constant expression}} \ |
| // expected-note {{in call to 'buildBoard(8)'}} |