diff options
8 files changed, 164 insertions, 1 deletions
diff --git a/clang-tools-extra/clang-tidy/fuchsia/CMakeLists.txt b/clang-tools-extra/clang-tidy/fuchsia/CMakeLists.txt index 28e4b0e781a..25da139495e 100644 --- a/clang-tools-extra/clang-tidy/fuchsia/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/fuchsia/CMakeLists.txt @@ -5,6 +5,7 @@ add_clang_library(clangTidyFuchsiaModule FuchsiaTidyModule.cpp OverloadedOperatorCheck.cpp StaticallyConstructedObjectsCheck.cpp + TrailingReturnCheck.cpp VirtualInheritanceCheck.cpp LINK_LIBS diff --git a/clang-tools-extra/clang-tidy/fuchsia/FuchsiaTidyModule.cpp b/clang-tools-extra/clang-tidy/fuchsia/FuchsiaTidyModule.cpp index ab4aaff9695..0eed7407490 100644 --- a/clang-tools-extra/clang-tidy/fuchsia/FuchsiaTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/fuchsia/FuchsiaTidyModule.cpp @@ -13,6 +13,7 @@ #include "DefaultArgumentsCheck.h" #include "OverloadedOperatorCheck.h" #include "StaticallyConstructedObjectsCheck.h" +#include "TrailingReturnCheck.h" #include "VirtualInheritanceCheck.h" using namespace clang::ast_matchers; @@ -31,6 +32,8 @@ public: "fuchsia-overloaded-operator"); CheckFactories.registerCheck<StaticallyConstructedObjectsCheck>( "fuchsia-statically-constructed-objects"); + CheckFactories.registerCheck<TrailingReturnCheck>( + "fuchsia-trailing-return"); CheckFactories.registerCheck<VirtualInheritanceCheck>( "fuchsia-virtual-inheritance"); } diff --git a/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.cpp b/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.cpp new file mode 100644 index 00000000000..27989d9bba1 --- /dev/null +++ b/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.cpp @@ -0,0 +1,56 @@ +//===--- TrailingReturnCheck.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 "TrailingReturnCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchersInternal.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace ast_matchers { + +const internal::VariadicDynCastAllOfMatcher<Type, DecltypeType> decltypeType; + +} // namespace ast_matchers + +namespace tidy { +namespace fuchsia { + +AST_MATCHER(FunctionDecl, hasTrailingReturn) { + return Node.getType()->castAs<FunctionProtoType>()->hasTrailingReturn(); +} + +void TrailingReturnCheck::registerMatchers(MatchFinder *Finder) { + + // Requires C++11 or later. + if (!getLangOpts().CPlusPlus11) + return; + + // Functions that have trailing returns are disallowed, except for those + // using decltype specifiers and lambda with otherwise unutterable + // return types. + Finder->addMatcher( + functionDecl(allOf(hasTrailingReturn(), + unless(anyOf(returns(decltypeType()), + hasParent(cxxRecordDecl(isLambda())))))) + .bind("decl"), + this); +} + +void TrailingReturnCheck::check(const MatchFinder::MatchResult &Result) { + if (const auto *D = Result.Nodes.getNodeAs<Decl>("decl")) + diag(D->getLocStart(), + "a trailing return type is disallowed for this type of declaration"); +} + +} // namespace fuchsia +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.h b/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.h new file mode 100644 index 00000000000..4a16c4e4ad2 --- /dev/null +++ b/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.h @@ -0,0 +1,37 @@ +//===--- TrailingReturnCheck.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_FUCHSIA_TRAILING_RETURN_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_FUCHSIA_TRAILING_RETURN_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace fuchsia { + +/// Functions that have trailing returns are disallowed, except for those +/// using decltype specifiers and lambda with otherwise unutterable +/// return types. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/fuchsia-trailing-return.html +class TrailingReturnCheck : public ClangTidyCheck { +public: + TrailingReturnCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace fuchsia +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_FUCHSIA_TRAILING_RETURN_H diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index 1531545bd34..01d47abdb82 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -70,7 +70,14 @@ Improvements to clang-tidy Warns if global, non-trivial objects with static storage are constructed, unless the object is statically initialized with a ``constexpr`` constructor or has no explicit constructor. - + +- New `fuchsia-trailing-return + <http://clang.llvm.org/extra/clang-tidy/checks/fuchsia-trailing-return.html>`_ check + + Functions that have trailing returns are disallowed, except for those + using decltype specifiers and lambda with otherwise unutterable + return types. + - New alias `hicpp-avoid-goto <http://clang.llvm.org/extra/clang-tidy/checks/hicpp-avoid-goto.html>`_ to `cppcoreguidelines-avoid-goto <http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines-avoid-goto.html>`_ diff --git a/clang-tools-extra/docs/clang-tidy/checks/fuchsia-trailing-return.rst b/clang-tools-extra/docs/clang-tidy/checks/fuchsia-trailing-return.rst new file mode 100644 index 00000000000..42e85c20e22 --- /dev/null +++ b/clang-tools-extra/docs/clang-tidy/checks/fuchsia-trailing-return.rst @@ -0,0 +1,35 @@ +.. title:: clang-tidy - fuchsia-trailing-return + +fuchsia-trailing-return +======================= + +Functions that have trailing returns are disallowed, except for those using +decltype specifiers and lambda with otherwise unutterable return types. + +For example: + +.. code-block:: c++ + + // No warning + int add_one(const int arg) { return arg; } + + // Warning + auto get_add_one() -> int (*)(const int) { + return add_one; + } + +Exceptions are made for lambdas and decltype specifiers: + +.. code-block:: c++ + + // No warning + auto lambda = [](double x, double y) -> double {return x + y;}; + + // No warning + template <typename T1, typename T2> + auto fn(const T1 &lhs, const T2 &rhs) -> decltype(lhs + rhs) { + return lhs + rhs; + } + + +See the features disallowed in Fuchsia at https://fuchsia.googlesource.com/zircon/+/master/docs/cxx.md diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst index 77b398b01ff..6a56b6a2d89 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst @@ -72,6 +72,7 @@ Clang-Tidy Checks fuchsia-default-arguments fuchsia-overloaded-operator fuchsia-statically-constructed-objects + fuchsia-trailing-return fuchsia-virtual-inheritance google-build-explicit-make-pair google-build-namespaces diff --git a/clang-tools-extra/test/clang-tidy/fuchsia-trailing-return.cpp b/clang-tools-extra/test/clang-tidy/fuchsia-trailing-return.cpp new file mode 100644 index 00000000000..f6c943ac873 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/fuchsia-trailing-return.cpp @@ -0,0 +1,23 @@ +// RUN: %check_clang_tidy %s fuchsia-trailing-return %t + +int add_one(const int arg) { return arg; } + +auto get_add_one() -> int (*)(const int) { + // CHECK-MESSAGES: [[@LINE-1]]:1: warning: a trailing return type is disallowed for this type of declaration + // CHECK-NEXT: auto get_add_one() -> int (*)(const int) { + return add_one; +} + +auto lambda = [](double x, double y) {return x + y;}; + +auto lambda2 = [](double x, double y) -> double {return x + y;}; + +int main() { + get_add_one()(5); + return 0; +} + +template <typename T1, typename T2> +auto fn(const T1 &lhs, const T2 &rhs) -> decltype(lhs + rhs) { + return lhs + rhs; +} |
