From 276fc642d38bbaa4aca00f517ba2f6f7bd138fe3 Mon Sep 17 00:00:00 2001 From: Alexander Kornienko Date: Sun, 29 Jun 2014 22:19:53 +0000 Subject: [PATCH] Another attempt to add a clang-tidy check for flagging C-style casts. Summary: The first version failed the SubstNonTypeTempateParmExpr-related test on some buildbots. This one uses the new substNonTypeTempateParmExpr matcher to filter out implicit C-style casts. This patch depends on D4327. Reviewers: djasper Reviewed By: djasper Subscribers: aemerson, cfe-commits Differential Revision: http://reviews.llvm.org/D4328 llvm-svn: 212002 --- .../clang-tidy/google/AvoidCStyleCastsCheck.cpp | 52 ++++++++++++++++++++++ .../clang-tidy/google/AvoidCStyleCastsCheck.h | 33 ++++++++++++++ clang-tools-extra/clang-tidy/google/CMakeLists.txt | 1 + .../clang-tidy/google/GoogleTidyModule.cpp | 4 ++ .../test/clang-tidy/avoid-c-style-casts.cpp | 24 ++++++++++ 5 files changed, 114 insertions(+) create mode 100644 clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp create mode 100644 clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.h create mode 100644 clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp diff --git a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp new file mode 100644 index 0000000..59914e0 --- /dev/null +++ b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp @@ -0,0 +1,52 @@ +//===--- AvoidCStyleCastsCheck.cpp - clang-tidy -----------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "AvoidCStyleCastsCheck.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace readability { + +void +AvoidCStyleCastsCheck::registerMatchers(ast_matchers::MatchFinder *Finder) { + Finder->addMatcher( + cStyleCastExpr( + // Filter out (EnumType)IntegerLiteral construct, which is generated + // for non-type template arguments of enum types. + // FIXME: Remove this once this is fixed in the AST. + unless(hasParent(substNonTypeTemplateParmExpr()))).bind("cast"), + this); +} + +void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) { + const auto *CastExpr = Result.Nodes.getNodeAs("cast"); + + // Ignore casts in macros for now. + if (CastExpr->getLocStart().isMacroID()) + return; + + // Casting to void is an idiomatic way to mute "unused variable" and similar + // warnings. + if (CastExpr->getTypeAsWritten()->isVoidType()) + return; + + diag(CastExpr->getLocStart(), "C-style casts are discouraged. Use " + "static_cast/const_cast/reinterpret_cast " + "instead."); + // FIXME: Suggest appropriate C++ cast. See [expr.cast] for cast notation + // semantics. +} + +} // namespace readability +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.h b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.h new file mode 100644 index 0000000..fc14e73 --- /dev/null +++ b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.h @@ -0,0 +1,33 @@ +//===--- AvoidCStyleCastsCheck.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_GOOGLE_AVOID_C_STYLE_CASTS_CHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_AVOID_C_STYLE_CASTS_CHECK_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace readability { + +/// \brief Finds usages of C-style casts. +/// +/// http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Casting#Casting +/// Corresponding cpplint.py check name: 'readability/casting'. +class AvoidCStyleCastsCheck : public ClangTidyCheck { +public: + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace readability +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_AVOID_C_STYLE_CASTS_CHECK_H diff --git a/clang-tools-extra/clang-tidy/google/CMakeLists.txt b/clang-tools-extra/clang-tidy/google/CMakeLists.txt index 3562e52..b5781e6 100644 --- a/clang-tools-extra/clang-tidy/google/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/google/CMakeLists.txt @@ -1,6 +1,7 @@ set(LLVM_LINK_COMPONENTS support) add_clang_library(clangTidyGoogleModule + AvoidCStyleCastsCheck.cpp ExplicitConstructorCheck.cpp GoogleTidyModule.cpp diff --git a/clang-tools-extra/clang-tidy/google/GoogleTidyModule.cpp b/clang-tools-extra/clang-tidy/google/GoogleTidyModule.cpp index 05787cf..34abfb3 100644 --- a/clang-tools-extra/clang-tidy/google/GoogleTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/google/GoogleTidyModule.cpp @@ -10,6 +10,7 @@ #include "../ClangTidy.h" #include "../ClangTidyModule.h" #include "../ClangTidyModuleRegistry.h" +#include "AvoidCStyleCastsCheck.h" #include "ExplicitConstructorCheck.h" using namespace clang::ast_matchers; @@ -23,6 +24,9 @@ public: CheckFactories.addCheckFactory( "google-explicit-constructor", new ClangTidyCheckFactory()); + CheckFactories.addCheckFactory( + "google-readability-casting", + new ClangTidyCheckFactory()); } }; diff --git a/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp b/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp new file mode 100644 index 0000000..8b9feb4 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp @@ -0,0 +1,24 @@ +// RUN: clang-tidy -checks=-*,google-readability-casting %s -- | FileCheck %s + +// CHECK-NOT: warning: + +bool g() { return false; } + +void f(int a, double b) { + int b1 = (int)b; + // CHECK: :[[@LINE-1]]:12: warning: C-style casts are discouraged. Use static_cast{{.*}} + + // CHECK-NOT: warning: + int b2 = int(b); + int b3 = static_cast(b); + int b4 = b; + double aa = a; + (void)b2; + return (void)g(); +} + +// CHECK-NOT: warning: +enum E { E1 = 1 }; +template +struct A { static const E ee = e; }; +struct B : public A {}; -- 2.7.4