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 LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_INCORRECTROUNDINGSCHECK_H_ 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: IncorrectRoundingsCheck(StringRef Name,ClangTidyContext * Context)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