xref: /llvm-project/clang-tools-extra/clang-tidy/bugprone/IntegerDivisionCheck.cpp (revision 43465bf3fd6cca715187ee7286c881cb210fc3c4)
1 //===--- IntegerDivisionCheck.cpp - clang-tidy-----------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "IntegerDivisionCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace bugprone {
19 
20 void IntegerDivisionCheck::registerMatchers(MatchFinder *Finder) {
21   const auto IntType = hasType(isInteger());
22 
23   const auto BinaryOperators = binaryOperator(anyOf(
24       hasOperatorName("%"), hasOperatorName("<<"), hasOperatorName(">>"),
25       hasOperatorName("<<"), hasOperatorName("^"), hasOperatorName("|"),
26       hasOperatorName("&"), hasOperatorName("||"), hasOperatorName("&&"),
27       hasOperatorName("<"), hasOperatorName(">"), hasOperatorName("<="),
28       hasOperatorName(">="), hasOperatorName("=="), hasOperatorName("!=")));
29 
30   const auto UnaryOperators =
31       unaryOperator(anyOf(hasOperatorName("~"), hasOperatorName("!")));
32 
33   const auto Exceptions =
34       anyOf(BinaryOperators, conditionalOperator(), binaryConditionalOperator(),
35             callExpr(IntType), explicitCastExpr(IntType), UnaryOperators);
36 
37   Finder->addMatcher(
38       binaryOperator(
39           hasOperatorName("/"), hasLHS(expr(IntType)), hasRHS(expr(IntType)),
40           hasAncestor(
41               castExpr(hasCastKind(CK_IntegralToFloating)).bind("FloatCast")),
42           unless(hasAncestor(
43               expr(Exceptions,
44                    hasAncestor(castExpr(equalsBoundNode("FloatCast")))))))
45           .bind("IntDiv"),
46       this);
47 }
48 
49 void IntegerDivisionCheck::check(const MatchFinder::MatchResult &Result) {
50   const auto *IntDiv = Result.Nodes.getNodeAs<BinaryOperator>("IntDiv");
51   diag(IntDiv->getBeginLoc(), "result of integer division used in a floating "
52                               "point context; possible loss of precision");
53 }
54 
55 } // namespace bugprone
56 } // namespace tidy
57 } // namespace clang
58