Index: clang-tidy/abseil/AbseilTidyModule.cpp =================================================================== --- clang-tidy/abseil/AbseilTidyModule.cpp +++ clang-tidy/abseil/AbseilTidyModule.cpp @@ -16,6 +16,7 @@ #include "NoInternalDependenciesCheck.h" #include "NoNamespaceCheck.h" #include "RedundantStrcatCallsCheck.h" +#include "SafelyScopedCheck.h" #include "StringFindStartswithCheck.h" #include "StrCatAppendCheck.h" @@ -37,6 +38,8 @@ CheckFactories.registerCheck("abseil-no-namespace"); CheckFactories.registerCheck( "abseil-redundant-strcat-calls"); + CheckFactories.registerCheck( + "abseil-safely-scoped"); CheckFactories.registerCheck( "abseil-str-cat-append"); CheckFactories.registerCheck( Index: clang-tidy/abseil/CMakeLists.txt =================================================================== --- clang-tidy/abseil/CMakeLists.txt +++ clang-tidy/abseil/CMakeLists.txt @@ -8,6 +8,7 @@ NoInternalDependenciesCheck.cpp NoNamespaceCheck.cpp RedundantStrcatCallsCheck.cpp + SafelyScopedCheck.cpp StrCatAppendCheck.cpp StringFindStartswithCheck.cpp Index: clang-tidy/abseil/SafelyScopedCheck.h =================================================================== --- /dev/null +++ clang-tidy/abseil/SafelyScopedCheck.h @@ -0,0 +1,36 @@ +//===--- SafelyScopedCheck.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_ABSEIL_SAFELYSCOPEDCHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ABSEIL_SAFELYSCOPEDCHECK_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace abseil { + +/// Detecting using declarations not in a namespace declaration or not in +/// the innermost layer of namespace declarations. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/abseil-safely-scoped.html +class SafelyScopedCheck : public ClangTidyCheck { +public: + SafelyScopedCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace abseil +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ABSEIL_SAFELYSCOPEDCHECK_H Index: clang-tidy/abseil/SafelyScopedCheck.cpp =================================================================== --- /dev/null +++ clang-tidy/abseil/SafelyScopedCheck.cpp @@ -0,0 +1,39 @@ +//===--- SafelyScopedCheck.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 "SafelyScopedCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace abseil { + +void SafelyScopedCheck::registerMatchers(MatchFinder *Finder) { + // The target using declaration is either: + // 1. not in any namespace declaration, or + // 2. in some namespace declaration but not in the innermost layer + Finder->addMatcher(usingDecl(eachOf( + usingDecl(unless(hasParent(namespaceDecl()))), + usingDecl(hasParent(namespaceDecl(forEach(namespaceDecl())))) ) + ).bind("use"), this); +} + +void SafelyScopedCheck::check(const MatchFinder::MatchResult &Result) { + const auto *MatchedDecl = Result.Nodes.getNodeAs("use"); + diag(MatchedDecl->getLocation(), "UsingDecl %0 should be in the innermost " + "scope. See: https://abseil.io/tips/119") + << MatchedDecl; +} + +} // namespace abseil +} // namespace tidy +} // namespace clang Index: docs/ReleaseNotes.rst =================================================================== --- docs/ReleaseNotes.rst +++ docs/ReleaseNotes.rst @@ -67,6 +67,12 @@ Improvements to clang-tidy -------------------------- +- New :doc:`abseil-safely-scoped + ` check. + + Finds instances of using declarations not in the innermost layer + of a series of namespaces. + - New :doc:`abseil-duration-division ` check. Index: docs/clang-tidy/checks/abseil-safely-scoped.rst =================================================================== --- /dev/null +++ docs/clang-tidy/checks/abseil-safely-scoped.rst @@ -0,0 +1,28 @@ +.. title:: clang-tidy - abseil-safely-scoped + +abseil-safely-scoped +==================== + +Flags using declarations that are not contained in an innermost +namespace, and suggests these declarations be moved elsewhere. + +Example: + +.. code-block:: c++ + + using something; // should be inside the innermost namespace bar below + + namespace foo { + namespace bar { + + } // bar + + using something_else; // shoulw be inside the innermost namespace bar above + + } // foo + +Placing convenience aliases in upper level namespaces can lead to ambiguity in +which name the compiler should use. + +See https://abseil.io/tips/119 for more explanation. + Index: docs/clang-tidy/checks/list.rst =================================================================== --- docs/clang-tidy/checks/list.rst +++ docs/clang-tidy/checks/list.rst @@ -10,8 +10,9 @@ abseil-no-internal-dependencies abseil-no-namespace abseil-redundant-strcat-calls - abseil-string-find-startswith + abseil-safely-scoped abseil-str-cat-append + abseil-string-find-startswith android-cloexec-accept android-cloexec-accept4 android-cloexec-creat @@ -151,6 +152,7 @@ hicpp-special-member-functions (redirects to cppcoreguidelines-special-member-functions) hicpp-static-assert (redirects to misc-static-assert) hicpp-undelegated-constructor (redirects to bugprone-undelegated-constructor) + hicpp-uppercase-literal-suffix (redirects to readability-uppercase-literal-suffix) hicpp-use-auto (redirects to modernize-use-auto) hicpp-use-emplace (redirects to modernize-use-emplace) hicpp-use-equals-default (redirects to modernize-use-equals-default) @@ -159,7 +161,6 @@ hicpp-use-nullptr (redirects to modernize-use-nullptr) hicpp-use-override (redirects to modernize-use-override) hicpp-vararg (redirects to cppcoreguidelines-pro-type-vararg) - hicpp-uppercase-literal-suffix (redirects to readability-uppercase-literal-suffix) llvm-header-guard llvm-include-order llvm-namespace-comment Index: test/clang-tidy/abseil-safely-scoped.cpp =================================================================== --- /dev/null +++ test/clang-tidy/abseil-safely-scoped.cpp @@ -0,0 +1,27 @@ +// RUN: %check_clang_tidy %s abseil-safely-scoped %t +namespace bar { + +class something { + +}; +} + +namespace foo { + +using bar::something; + +namespace { + +} // anonymous namespace +} // namespace foo +// CHECK-MESSAGES: :[[@LINE-6]]:12: warning: UsingDecl 'something' should be in the innermost scope. See: https://abseil.io/tips/119 [abseil-safely-scoped] + +namespace foo { + +namespace { + +using ::bar::something; + +} // anonymous namespace +} // namespace foo +