1 | //===--- IncorrectRoundingsCheck.h - clang-tidy -----------------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_INCORRECTROUNDINGSCHECK_H_ |
10 | #define |
11 | |
12 | #include "../ClangTidyCheck.h" |
13 | |
14 | namespace clang::tidy::bugprone { |
15 | |
16 | /// Checks the usage of patterns known to produce incorrect rounding. |
17 | /// Programmers often use |
18 | /// (int)(double_expression + 0.5) |
19 | /// to round the double expression to an integer. The problem with this |
20 | /// 1. It is unnecessarily slow. |
21 | /// 2. It is incorrect. The number 0.499999975 (smallest representable float |
22 | /// number below 0.5) rounds to 1.0. Even worse behavior for negative |
23 | /// numbers where both -0.5f and -1.4f both round to 0.0. |
24 | class IncorrectRoundingsCheck : public ClangTidyCheck { |
25 | public: |
26 | IncorrectRoundingsCheck(StringRef Name, ClangTidyContext *Context) |
27 | : ClangTidyCheck(Name, Context) {} |
28 | void registerMatchers(ast_matchers::MatchFinder *Finder) override; |
29 | void check(const ast_matchers::MatchFinder::MatchResult &Result) override; |
30 | }; |
31 | |
32 | } // namespace clang::tidy::bugprone |
33 | |
34 | #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_INCORRECTROUNDINGSCHECK_H_ |
35 | |