1 //===--- IntegerDivisionCheck.cpp - clang-tidy-----------------------------===//
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 #include "IntegerDivisionCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 
13 using namespace clang::ast_matchers;
14 
15 namespace clang {
16 namespace tidy {
17 namespace bugprone {
18 
19 void IntegerDivisionCheck::registerMatchers(MatchFinder *Finder) {
20   const auto IntType = hasType(isInteger());
21 
22   const auto BinaryOperators = binaryOperator(
23       hasAnyOperatorName("%", "<<", ">>", "<<", "^", "|", "&", "||", "&&", "<",
24                          ">", "<=", ">=", "==", "!="));
25 
26   const auto UnaryOperators = unaryOperator(hasAnyOperatorName("~", "!"));
27 
28   const auto Exceptions =
29       anyOf(BinaryOperators, conditionalOperator(), binaryConditionalOperator(),
30             callExpr(IntType), explicitCastExpr(IntType), UnaryOperators);
31 
32   Finder->addMatcher(
33       traverse(ast_type_traits::TK_AsIs,
34                binaryOperator(
35                    hasOperatorName("/"), hasLHS(expr(IntType)),
36                    hasRHS(expr(IntType)),
37                    hasAncestor(castExpr(hasCastKind(CK_IntegralToFloating))
38                                    .bind("FloatCast")),
39                    unless(hasAncestor(expr(
40                        Exceptions,
41                        hasAncestor(castExpr(equalsBoundNode("FloatCast")))))))
42                    .bind("IntDiv")),
43       this);
44 }
45 
46 void IntegerDivisionCheck::check(const MatchFinder::MatchResult &Result) {
47   const auto *IntDiv = Result.Nodes.getNodeAs<BinaryOperator>("IntDiv");
48   diag(IntDiv->getBeginLoc(), "result of integer division used in a floating "
49                               "point context; possible loss of precision");
50 }
51 
52 } // namespace bugprone
53 } // namespace tidy
54 } // namespace clang
55