diff options
5 files changed, 115 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt index 02f666cb0fe..ed15e46c741 100644 --- a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt @@ -14,6 +14,7 @@ add_clang_library(clangTidyMiscModule StaticAssertCheck.cpp SwappedArgumentsCheck.cpp UndelegatedConstructor.cpp + UnusedAliasDeclsCheck.cpp UnusedParametersCheck.cpp UnusedRAIICheck.cpp UniqueptrResetReleaseCheck.cpp diff --git a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp index 8502e5a92c3..8c401eecd4c 100644 --- a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp @@ -23,6 +23,7 @@ #include "SwappedArgumentsCheck.h" #include "UndelegatedConstructor.h" #include "UniqueptrResetReleaseCheck.h" +#include "UnusedAliasDeclsCheck.h" #include "UnusedParametersCheck.h" #include "UnusedRAIICheck.h" #include "UseOverrideCheck.h" @@ -59,6 +60,8 @@ public: "misc-undelegated-constructor"); CheckFactories.registerCheck<UniqueptrResetReleaseCheck>( "misc-uniqueptr-reset-release"); + CheckFactories.registerCheck<UnusedAliasDeclsCheck>( + "misc-unused-alias-decls"); CheckFactories.registerCheck<UnusedParametersCheck>( "misc-unused-parameters"); CheckFactories.registerCheck<UnusedRAIICheck>("misc-unused-raii"); diff --git a/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.cpp new file mode 100644 index 00000000000..a56c1bfa8bd --- /dev/null +++ b/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.cpp @@ -0,0 +1,63 @@ +//===--- UnusedAliasDeclsCheck.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 "UnusedAliasDeclsCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/Lex/Lexer.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { + +// FIXME: Move this to ASTMatchers.h. +const ast_matchers::internal::VariadicDynCastAllOfMatcher< + Decl, NamespaceAliasDecl> namespaceAliasDecl; + +void UnusedAliasDeclsCheck::registerMatchers(MatchFinder *Finder) { + Finder->addMatcher(namespaceAliasDecl().bind("alias"), this); + Finder->addMatcher(nestedNameSpecifier().bind("nns"), this); +} + +void UnusedAliasDeclsCheck::check(const MatchFinder::MatchResult &Result) { + if (const auto *AliasDecl = Result.Nodes.getNodeAs<Decl>("alias")) { + // We cannot do anything about headers (yet), as the alias declarations used + // in one header could be used by some other translation unit. + if (!Result.SourceManager->isInMainFile(AliasDecl->getLocation())) + return; + + FoundDecls[AliasDecl] = CharSourceRange::getCharRange( + AliasDecl->getLocStart(), + Lexer::findLocationAfterToken( + AliasDecl->getLocEnd(), tok::semi, *Result.SourceManager, + Result.Context->getLangOpts(), + /*SkipTrailingWhitespaceAndNewLine=*/true)); + return; + } + + if (const auto *NestedName = + Result.Nodes.getNodeAs<NestedNameSpecifier>("nns")) { + if (const auto *AliasDecl = NestedName->getAsNamespaceAlias()) { + FoundDecls[AliasDecl] = CharSourceRange(); + } + } +} + +void UnusedAliasDeclsCheck::onEndOfTranslationUnit() { + for (const auto &FoundDecl : FoundDecls) { + if (!FoundDecl.second.isValid()) + continue; + diag(FoundDecl.first->getLocation(), "this namespace alias decl is unused") + << FixItHint::CreateRemoval(FoundDecl.second); + } +} + +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.h b/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.h new file mode 100644 index 00000000000..c025c1ebc19 --- /dev/null +++ b/clang-tools-extra/clang-tidy/misc/UnusedAliasDeclsCheck.h @@ -0,0 +1,35 @@ +//===--- UnusedAliasDeclsCheck.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_MISC_UNUSED_ALIAS_DECLS_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_ALIAS_DECLS_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { + +/// \brief Finds unused namespace alias declarations. +class UnusedAliasDeclsCheck : public ClangTidyCheck { +public: + UnusedAliasDeclsCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; + void onEndOfTranslationUnit(); + +private: + llvm::DenseMap<const Decl *, CharSourceRange> FoundDecls; +}; + +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_ALIAS_DECLS_H + diff --git a/clang-tools-extra/test/clang-tidy/misc-unused-alias-decls.cpp b/clang-tools-extra/test/clang-tidy/misc-unused-alias-decls.cpp new file mode 100644 index 00000000000..01d6d9a0406 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/misc-unused-alias-decls.cpp @@ -0,0 +1,13 @@ +// RUN: $(dirname %s)/check_clang_tidy.sh %s misc-unused-alias-decls %t +// REQUIRES: shell + +namespace my_namespace { +class C {}; +} + +namespace unused_alias = ::my_namespace; // eol-comments aren't removed (yet) +// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: this namespace alias decl is unused +// CHECK-FIXES: {{^}}// eol-comments aren't removed (yet) + +namespace used_alias = ::my_namespace; +void f() { used_alias::C c; } |
