Author: juliehockett Date: Wed Jan 17 13:18:15 2018 New Revision: 322759 URL: http://llvm.org/viewvc/llvm-project?rev=322759&view=rev Log: [clang-tidy] Adding Fuchsia checker for trailing returns
Adds a check to the Fuchsia module to warn if a function has a trailing return. See https://fuchsia.googlesource.com/zircon/+/master/docs/cxx.md for reference. Differential Revision: https://reviews.llvm.org/D42116 Added: clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.cpp clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.h clang-tools-extra/trunk/docs/clang-tidy/checks/fuchsia-trailing-return.rst clang-tools-extra/trunk/test/clang-tidy/fuchsia-trailing-return.cpp Modified: clang-tools-extra/trunk/clang-tidy/fuchsia/CMakeLists.txt clang-tools-extra/trunk/clang-tidy/fuchsia/FuchsiaTidyModule.cpp clang-tools-extra/trunk/docs/ReleaseNotes.rst clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Modified: clang-tools-extra/trunk/clang-tidy/fuchsia/CMakeLists.txt URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/fuchsia/CMakeLists.txt?rev=322759&r1=322758&r2=322759&view=diff ============================================================================== --- clang-tools-extra/trunk/clang-tidy/fuchsia/CMakeLists.txt (original) +++ clang-tools-extra/trunk/clang-tidy/fuchsia/CMakeLists.txt Wed Jan 17 13:18:15 2018 @@ -5,6 +5,7 @@ add_clang_library(clangTidyFuchsiaModule FuchsiaTidyModule.cpp OverloadedOperatorCheck.cpp StaticallyConstructedObjectsCheck.cpp + TrailingReturnCheck.cpp VirtualInheritanceCheck.cpp LINK_LIBS Modified: clang-tools-extra/trunk/clang-tidy/fuchsia/FuchsiaTidyModule.cpp URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/fuchsia/FuchsiaTidyModule.cpp?rev=322759&r1=322758&r2=322759&view=diff ============================================================================== --- clang-tools-extra/trunk/clang-tidy/fuchsia/FuchsiaTidyModule.cpp (original) +++ clang-tools-extra/trunk/clang-tidy/fuchsia/FuchsiaTidyModule.cpp Wed Jan 17 13:18:15 2018 @@ -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"); } Added: clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.cpp URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.cpp?rev=322759&view=auto ============================================================================== --- clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.cpp (added) +++ clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.cpp Wed Jan 17 13:18:15 2018 @@ -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 Added: clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.h URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.h?rev=322759&view=auto ============================================================================== --- clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.h (added) +++ clang-tools-extra/trunk/clang-tidy/fuchsia/TrailingReturnCheck.h Wed Jan 17 13:18:15 2018 @@ -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 Modified: clang-tools-extra/trunk/docs/ReleaseNotes.rst URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/ReleaseNotes.rst?rev=322759&r1=322758&r2=322759&view=diff ============================================================================== --- clang-tools-extra/trunk/docs/ReleaseNotes.rst (original) +++ clang-tools-extra/trunk/docs/ReleaseNotes.rst Wed Jan 17 13:18:15 2018 @@ -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>`_ Added: clang-tools-extra/trunk/docs/clang-tidy/checks/fuchsia-trailing-return.rst URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/fuchsia-trailing-return.rst?rev=322759&view=auto ============================================================================== --- clang-tools-extra/trunk/docs/clang-tidy/checks/fuchsia-trailing-return.rst (added) +++ clang-tools-extra/trunk/docs/clang-tidy/checks/fuchsia-trailing-return.rst Wed Jan 17 13:18:15 2018 @@ -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 Modified: clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst?rev=322759&r1=322758&r2=322759&view=diff ============================================================================== --- clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst (original) +++ clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Wed Jan 17 13:18:15 2018 @@ -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 Added: clang-tools-extra/trunk/test/clang-tidy/fuchsia-trailing-return.cpp URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/fuchsia-trailing-return.cpp?rev=322759&view=auto ============================================================================== --- clang-tools-extra/trunk/test/clang-tidy/fuchsia-trailing-return.cpp (added) +++ clang-tools-extra/trunk/test/clang-tidy/fuchsia-trailing-return.cpp Wed Jan 17 13:18:15 2018 @@ -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; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
