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