Index: clang-tidy/cppcoreguidelines/CMakeLists.txt =================================================================== --- clang-tidy/cppcoreguidelines/CMakeLists.txt +++ clang-tidy/cppcoreguidelines/CMakeLists.txt @@ -2,6 +2,7 @@ add_clang_library(clangTidyCppCoreGuidelinesModule CppCoreGuidelinesTidyModule.cpp + ProTypeConstCastCheck.cpp ProTypeReinterpretCastCheck.cpp LINK_LIBS Index: clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp =================================================================== --- clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp +++ clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp @@ -10,6 +10,7 @@ #include "../ClangTidy.h" #include "../ClangTidyModule.h" #include "../ClangTidyModuleRegistry.h" +#include "ProTypeConstCastCheck.h" #include "ProTypeReinterpretCastCheck.h" namespace clang { @@ -19,6 +20,8 @@ class CppCoreGuidelinesModule : public ClangTidyModule { public: void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override { + CheckFactories.registerCheck( + "cppcoreguidelines-pro-type-const-cast"); CheckFactories.registerCheck( "cppcoreguidelines-pro-type-reinterpret-cast"); } Index: clang-tidy/cppcoreguidelines/ProTypeConstCastCheck.h =================================================================== --- /dev/null +++ clang-tidy/cppcoreguidelines/ProTypeConstCastCheck.h @@ -0,0 +1,34 @@ +//===--- ProTypeConstCastCheck.h - clang-tidy--------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_CONST_CAST_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_CONST_CAST_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { + +/// This check flags all instances of const_cast +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines-pro-type-const-cast.html +class ProTypeConstCastCheck : public ClangTidyCheck { +public: + ProTypeConstCastCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_TYPE_CONST_CAST_H + Index: clang-tidy/cppcoreguidelines/ProTypeConstCastCheck.cpp =================================================================== --- /dev/null +++ clang-tidy/cppcoreguidelines/ProTypeConstCastCheck.cpp @@ -0,0 +1,33 @@ +//===--- ProTypeConstCastCheck.cpp - clang-tidy----------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "ProTypeConstCastCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { + +void ProTypeConstCastCheck::registerMatchers(MatchFinder *Finder) { + if(!getLangOpts().CPlusPlus) + return; + + Finder->addMatcher(cxxConstCastExpr().bind("cast"), this); +} + +void ProTypeConstCastCheck::check(const MatchFinder::MatchResult &Result) { + const auto *MatchedCast = Result.Nodes.getNodeAs("cast"); + diag(MatchedCast->getOperatorLoc(), "do not use const_cast"); +} + +} // namespace tidy +} // namespace clang + Index: docs/clang-tidy/checks/cppcoreguidelines-pro-type-const-cast.rst =================================================================== --- /dev/null +++ docs/clang-tidy/checks/cppcoreguidelines-pro-type-const-cast.rst @@ -0,0 +1,9 @@ +cppcoreguidelines-pro-type-const-cast +===================================== + +This check flags all uses of const_cast in C++ code. + +Modifying a variable that was declared const is undefined behavior, even with const_cast. + +This rule is part of the "Type safety" profile of the C++ Core Guidelines, see +https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-type3-dont-use-const_cast-to-cast-away-const-ie-at-all. Index: docs/clang-tidy/checks/list.rst =================================================================== --- docs/clang-tidy/checks/list.rst +++ docs/clang-tidy/checks/list.rst @@ -3,6 +3,7 @@ .. toctree:: cert-variadic-function-def + cppcoreguidelines-pro-type-const-cast cppcoreguidelines-pro-type-reinterpret-cast google-build-explicit-make-pair google-build-namespaces Index: test/clang-tidy/cppcoreguidelines-pro-type-const-cast.cpp =================================================================== --- /dev/null +++ test/clang-tidy/cppcoreguidelines-pro-type-const-cast.cpp @@ -0,0 +1,6 @@ +// RUN: %python %S/check_clang_tidy.py %s cppcoreguidelines-pro-type-const-cast %t + +const int* i; +int* j; +void f() { j = const_cast(i); } +// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: do not use const_cast [cppcoreguidelines-pro-type-const-cast]