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

   1 //===--- BitwisePointerCastCheck.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 "BitwisePointerCastCheck.h"
  10 #include "clang/ASTMatchers/ASTMatchFinder.h"
  11
  12 using namespace clang::ast_matchers;
  13
  14 namespace clang::tidy::bugprone {
  15
  16 void BitwisePointerCastCheck::registerMatchers(MatchFinder *Finder) {
  17   if (getLangOpts().CPlusPlus20) {
  18     auto IsPointerType = refersToType(qualType(isAnyPointer()));
  19     Finder->addMatcher(callExpr(hasDeclaration(functionDecl(allOf(
  20                                     hasName("::std::bit_cast"),
  21                                     hasTemplateArgument(0, IsPointerType),
  22                                     hasTemplateArgument(1, IsPointerType)))))
  23                            .bind("bit_cast"),
  24                        this);
  25   }
  26
  27   auto IsDoublePointerType =
  28       hasType(qualType(pointsTo(qualType(isAnyPointer()))));
  29   Finder->addMatcher(callExpr(hasArgument(0, IsDoublePointerType),
  30                               hasArgument(1, IsDoublePointerType),
  31                               hasDeclaration(functionDecl(hasName("::memcpy"))))
  32                          .bind("memcpy"),
  33                      this);
  34 }
  35
  36 void BitwisePointerCastCheck::check(const MatchFinder::MatchResult &Result) {
  37   if (const auto *Call = Result.Nodes.getNodeAs<CallExpr>("bit_cast"))
  38     diag(Call->getBeginLoc(),
  39          "do not use 'std::bit_cast' to cast between pointers")
  40         << Call->getSourceRange();
  41   else if (const auto *Call = Result.Nodes.getNodeAs<CallExpr>("memcpy"))
  42     diag(Call->getBeginLoc(), "do not use 'memcpy' to cast between pointers")
  43         << Call->getSourceRange();
  44 }
  45
  46 } // namespace clang::tidy::bugprone