UnusedAliasDeclsCheck.cpp
UnusedParametersCheck.cpp
UnusedUsingDeclsCheck.cpp
+ UseAnonymousNamespaceCheck.cpp
LINK_LIBS
clangAnalysis
#include "UnusedAliasDeclsCheck.h"
#include "UnusedParametersCheck.h"
#include "UnusedUsingDeclsCheck.h"
+#include "UseAnonymousNamespaceCheck.h"
namespace clang {
namespace tidy {
"misc-unused-parameters");
CheckFactories.registerCheck<UnusedUsingDeclsCheck>(
"misc-unused-using-decls");
+ CheckFactories.registerCheck<UseAnonymousNamespaceCheck>(
+ "misc-use-anonymous-namespace");
}
};
--- /dev/null
+//===--- UseAnonymousNamespaceCheck.cpp - clang-tidy ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "UseAnonymousNamespaceCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace misc {
+namespace {
+AST_POLYMORPHIC_MATCHER(isStatic, AST_POLYMORPHIC_SUPPORTED_TYPES(FunctionDecl,
+ VarDecl)) {
+ return Node.getStorageClass() == SC_Static;
+}
+
+AST_MATCHER(FunctionDecl, isMemberFunction) {
+ return llvm::isa<CXXMethodDecl>(&Node);
+}
+AST_MATCHER(VarDecl, isStaticDataMember) { return Node.isStaticDataMember(); }
+} // namespace
+
+static bool isInAnonymousNamespace(const Decl *Decl) {
+ const DeclContext *DC = Decl->getDeclContext();
+ if (DC && DC->isNamespace()) {
+ const auto *ND = llvm::cast<NamespaceDecl>(DC);
+ if (ND && ND->isAnonymousNamespace())
+ return true;
+ }
+ return false;
+}
+
+template <typename T>
+void UseAnonymousNamespaceCheck::processMatch(const T *MatchedDecl) {
+ StringRef Type = llvm::isa<VarDecl>(MatchedDecl) ? "variable" : "function";
+ if (isInAnonymousNamespace(MatchedDecl))
+ diag(MatchedDecl->getLocation(), "%0 %1 declared 'static' in "
+ "anonymous namespace, remove 'static'")
+ << Type << MatchedDecl;
+ else
+ diag(MatchedDecl->getLocation(),
+ "%0 %1 declared 'static', move to anonymous namespace instead")
+ << Type << MatchedDecl;
+}
+
+void UseAnonymousNamespaceCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ functionDecl(isStatic(), unless(isMemberFunction())).bind("func"), this);
+ Finder->addMatcher(
+ varDecl(isStatic(), unless(anyOf(isStaticLocal(), isStaticDataMember())))
+ .bind("var"),
+ this);
+}
+
+void UseAnonymousNamespaceCheck::check(const MatchFinder::MatchResult &Result) {
+ if (const auto *MatchedDecl = Result.Nodes.getNodeAs<FunctionDecl>("func"))
+ processMatch(MatchedDecl);
+
+ if (const auto *MatchedDecl = Result.Nodes.getNodeAs<VarDecl>("var"))
+ processMatch(MatchedDecl);
+}
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
--- /dev/null
+//===--- UseAnonymousNamespaceCheck.h - clang-tidy --------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_USEANONYMOUSNAMESPACECHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_USEANONYMOUSNAMESPACECHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang {
+namespace tidy {
+namespace misc {
+
+/// Warns when using 'static' functions or variables at global scope, and
+/// suggests moving them to an anonymous namespace. It also suggests removing
+/// 'static' if they are already inside an anonymous namespace.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-anonymous-namespace.html
+class UseAnonymousNamespaceCheck : public ClangTidyCheck {
+public:
+ UseAnonymousNamespaceCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+ return LangOpts.CPlusPlus;
+ }
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+ template <typename T> void processMatch(const T *MatchedDecl);
+};
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_USEANONYMOUSNAMESPACECHECK_H
Warns when using ``do-while`` loops.
+- New :doc:`misc-use-anonymous-namespace
+ <clang-tidy/checks/misc/use-anonymous-namespace>` check.
+
+ Warns when using ``static`` function or variables at global scope, and suggests
+ moving them into an anonymous namespace.
+
New check aliases
^^^^^^^^^^^^^^^^^
`misc-unused-alias-decls <misc/unused-alias-decls.html>`_, "Yes"
`misc-unused-parameters <misc/unused-parameters.html>`_, "Yes"
`misc-unused-using-decls <misc/unused-using-decls.html>`_, "Yes"
+ `misc-use-anonymous-namespace <misc/use-anonymous-namespace.html>`_,
`modernize-avoid-bind <modernize/avoid-bind.html>`_, "Yes"
`modernize-avoid-c-arrays <modernize/avoid-c-arrays.html>`_,
`modernize-concat-nested-namespaces <modernize/concat-nested-namespaces.html>`_, "Yes"
--- /dev/null
+.. title:: clang-tidy - misc-use-anonymous-namespace
+
+misc-use-anonymous-namespace
+============================
+
+Finds instances of ``static`` functions or variables declared at global scope
+that could instead be moved into an anonymous namespace. It also detects
+instances moved to an anonymous namespace that still keep the redundant
+``static``.
+
+Anonymous namespaces are the "superior alternative" according to the C++
+Standard. ``static`` was proposed for deprecation, but later un-deprecated to
+keep C compatibility [1]. ``static`` is an overloaded term with different meanings in
+different contexts, so it can create confusion.
+
+Examples:
+
+.. code-block:: c++
+
+ // Bad
+ static void foo();
+ static int x;
+
+ // Good
+ namespace {
+ void foo();
+ int x;
+ } // namespace
+
+.. code-block:: c++
+
+ // Bad
+ namespace {
+ static void foo();
+ static int x;
+ }
+
+ // Good
+ namespace {
+ void foo();
+ int x;
+ } // namespace
+
+[1] `Undeprecating static <https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1012>`_
--- /dev/null
+// RUN: %check_clang_tidy %s misc-use-anonymous-namespace %t
+
+static void f1();
+// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: function 'f1' declared 'static', move to anonymous namespace instead [misc-use-anonymous-namespace]
+static int v1;
+// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: variable 'v1' declared 'static', move to anonymous namespace instead
+
+namespace {
+ static void f2();
+ // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: function 'f2' declared 'static' in anonymous namespace, remove 'static'
+ static int v2;
+ // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: variable 'v2' declared 'static' in anonymous namespace, remove 'static'
+}
+
+namespace a {
+ static void f3();
+ // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: function 'f3' declared 'static', move to anonymous namespace instead
+ static int v3;
+ // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: variable 'v3' declared 'static', move to anonymous namespace instead
+}
+
+namespace a {
+namespace {
+ static void f4();
+ // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: function 'f4' declared 'static' in anonymous namespace, remove 'static'
+ static int v4;
+ // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: variable 'v4' declared 'static' in anonymous namespace, remove 'static'
+}
+}
+
+// OK
+void f5();
+int v5;
+
+// OK
+namespace {
+ void f6();
+ int v6;
+}
+
+// OK
+namespace a {
+namespace {
+ void f7();
+ int v7;
+}
+}
+
+// OK
+struct Foo {
+ static void f();
+ static int x;
+};
+
+// OK
+void foo()
+{
+ static int x;
+}