xref: /llvm-project/clang-tools-extra/clang-tidy/bugprone/CastingThroughVoidCheck.cpp (revision d25e24a0eb909b7604572d28d15cbe648ecccd90)
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
47