clang-tools-extra/clang-tidy/bugprone/IntegerDivisionCheck.cpp

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