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

   1 //===--- CastingThroughVoidCheck.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 "CastingThroughVoidCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/AST/Expr.h"
  12 #include "clang/AST/Type.h"
  13 #include "clang/ASTMatchers/ASTMatchFinder.h"
  14 #include "clang/ASTMatchers/ASTMatchers.h"
  15 #include "llvm/ADT/StringSet.h"
  16
  17 using namespace clang::ast_matchers;
  18
  19 namespace clang::tidy::bugprone {
  20
  21 void CastingThroughVoidCheck::registerMatchers(MatchFinder *Finder) {
  22   Finder->addMatcher(
  23       explicitCastExpr(
  24           hasDestinationType(
  25               qualType(unless(hasCanonicalType(pointsTo(voidType()))))
  26                   .bind("target_type")),
  27           hasSourceExpression(
  28               explicitCastExpr(
  29                   hasSourceExpression(
  30                       expr(hasType(qualType().bind("source_type")))),
  31                   hasDestinationType(
  32                       qualType(pointsTo(voidType())).bind("void_type")))
  33                   .bind("cast"))),
  34       this);
  35 }
  36
  37 void CastingThroughVoidCheck::check(const MatchFinder::MatchResult &Result) {
  38   const auto TT = *Result.Nodes.getNodeAs<QualType>("target_type");
  39   const auto ST = *Result.Nodes.getNodeAs<QualType>("source_type");
  40   const auto VT = *Result.Nodes.getNodeAs<QualType>("void_type");
  41   const auto *CE = Result.Nodes.getNodeAs<ExplicitCastExpr>("cast");
  42   diag(CE->getExprLoc(), "do not cast %0 to %1 through %2") << ST << TT << VT;
  43 }
  44
  45 } // namespace clang::tidy::bugprone