> On Apr 5, 2018, at 12:39 PM, John McCall <rjmcc...@apple.com> wrote: > > > >> On Apr 4, 2018, at 7:37 PM, Akira Hatanaka <ahatan...@apple.com >> <mailto:ahatan...@apple.com>> wrote: >> >> >> >>> On Apr 4, 2018, at 4:24 PM, Akira Hatanaka via cfe-commits >>> <cfe-commits@lists.llvm.org <mailto:cfe-commits@lists.llvm.org>> wrote: >>> >>>> >>>> On Apr 4, 2018, at 3:38 PM, Richard Smith <rich...@metafoo.co.uk >>>> <mailto:rich...@metafoo.co.uk>> wrote: >>>> >>>> Hi Akira, >>>> >>>> This change has broken the C++ versions of these type traits for classes >>>> with volatile members. Such classes are required to claim to be trivial >>>> per C++ DR 2094 >>>> (http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#2094 >>>> <http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#2094>) but >>>> return false from isNonTrivialToPrimitiveCopy(). >>>> >>> >>> Oh that’s right. The function returns false when >>> isNonTrivialToPrimitiveCopy() returns PCK_VolatileTrivial. That is wrong. >>> >>>> Also, exposing these __has_* traits more widely seems like a backwards >>>> step to me: these traits are deprecated, near-useless, and we're trying to >>>> remove them. No code should be using them under any circumstances; the >>>> __is_* traits should be used instead. >>>> >>> >>> The __is_* traits (is_trivially_copy_constructible, etc.) are templates >>> defined in libcxx, so it seems that we can’t use them when compiling in C >>> mode. Is it OK to add their definitions to TokenKinds.def as non-C++ >>> keywords? >>> >> >> Or perhaps redefine the six __has_* traits used here as non-C++ (KEYNOCXX or >> ‘KEYC99 | KEYC11') keywords? > > I think Richard is talking about e.g. the __is_trivially_destructible > intrinsic type trait function rather than std::is_trivially_destructible. > > Do we have a concrete need to expose these type traits to C? >
No, no one has asked any of these type traits to be exposed to C yet. Do you think we should just revert the patch and wait until someone asks for those type traits to be available in C? > John. > >> >>>> On 27 March 2018 at 17:12, Akira Hatanaka via cfe-commits >>>> <cfe-commits@lists.llvm.org <mailto:cfe-commits@lists.llvm.org>> wrote: >>>> Author: ahatanak >>>> Date: Tue Mar 27 17:12:08 2018 >>>> New Revision: 328680 >>>> >>>> URL: http://llvm.org/viewvc/llvm-project?rev=328680&view=rev >>>> <http://llvm.org/viewvc/llvm-project?rev=328680&view=rev> >>>> Log: >>>> [ObjC] Make C++ triviality type traits available to non-trivial C >>>> structs. >>>> >>>> r326307 and r327870 made changes that allowed using non-trivial C >>>> structs with fields qualified with __strong or __weak. This commit makes >>>> the following C++ triviality type traits available to non-trivial C >>>> structs: >>>> >>>> __has_trivial_assign >>>> __has_trivial_move_assign >>>> __has_trivial_copy >>>> __has_trivial_move_constructor >>>> __has_trivial_constructor >>>> __has_trivial_destructor >>>> >>>> rdar://problem/33599681 <rdar://problem/33599681> >>>> >>>> Differential Revision: https://reviews.llvm.org/D44913 >>>> <https://reviews.llvm.org/D44913> >>>> >>>> Added: >>>> cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m >>>> Modified: >>>> cfe/trunk/include/clang/Basic/TokenKinds.def >>>> cfe/trunk/lib/Sema/SemaExprCXX.cpp >>>> >>>> Modified: cfe/trunk/include/clang/Basic/TokenKinds.def >>>> URL: >>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/TokenKinds.def?rev=328680&r1=328679&r2=328680&view=diff >>>> >>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/TokenKinds.def?rev=328680&r1=328679&r2=328680&view=diff> >>>> ============================================================================== >>>> --- cfe/trunk/include/clang/Basic/TokenKinds.def (original) >>>> +++ cfe/trunk/include/clang/Basic/TokenKinds.def Tue Mar 27 17:12:08 2018 >>>> @@ -433,12 +433,12 @@ TYPE_TRAIT_1(__has_nothrow_assign, HasNo >>>> TYPE_TRAIT_1(__has_nothrow_move_assign, HasNothrowMoveAssign, KEYCXX) >>>> TYPE_TRAIT_1(__has_nothrow_copy, HasNothrowCopy, KEYCXX) >>>> TYPE_TRAIT_1(__has_nothrow_constructor, HasNothrowConstructor, KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_assign, HasTrivialAssign, KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_move_assign, HasTrivialMoveAssign, KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_copy, HasTrivialCopy, KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_constructor, HasTrivialDefaultConstructor, >>>> KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_move_constructor, HasTrivialMoveConstructor, >>>> KEYCXX) >>>> -TYPE_TRAIT_1(__has_trivial_destructor, HasTrivialDestructor, KEYCXX) >>>> +TYPE_TRAIT_1(__has_trivial_assign, HasTrivialAssign, KEYALL) >>>> +TYPE_TRAIT_1(__has_trivial_move_assign, HasTrivialMoveAssign, KEYALL) >>>> +TYPE_TRAIT_1(__has_trivial_copy, HasTrivialCopy, KEYALL) >>>> +TYPE_TRAIT_1(__has_trivial_constructor, HasTrivialDefaultConstructor, >>>> KEYALL) >>>> +TYPE_TRAIT_1(__has_trivial_move_constructor, HasTrivialMoveConstructor, >>>> KEYALL) >>>> +TYPE_TRAIT_1(__has_trivial_destructor, HasTrivialDestructor, KEYALL) >>>> TYPE_TRAIT_1(__has_virtual_destructor, HasVirtualDestructor, KEYCXX) >>>> TYPE_TRAIT_1(__is_abstract, IsAbstract, KEYCXX) >>>> TYPE_TRAIT_1(__is_aggregate, IsAggregate, KEYCXX) >>>> >>>> Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp >>>> URL: >>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=328680&r1=328679&r2=328680&view=diff >>>> >>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=328680&r1=328679&r2=328680&view=diff> >>>> ============================================================================== >>>> --- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original) >>>> +++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Tue Mar 27 17:12:08 2018 >>>> @@ -4513,6 +4513,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> // does not correctly compute triviality in the presence of multiple >>>> special >>>> // members of the same kind. Revisit this once the g++ bug is fixed. >>>> case UTT_HasTrivialDefaultConstructor: >>>> + if (T.isNonTrivialToPrimitiveDefaultInitialize()) >>>> + return false; >>>> // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html >>>> <http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html>: >>>> // If __is_pod (type) is true then the trait is true, else if type >>>> is >>>> // a cv class or union type (or array thereof) with a trivial >>>> default >>>> @@ -4524,6 +4526,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> !RD->hasNonTrivialDefaultConstructor(); >>>> return false; >>>> case UTT_HasTrivialMoveConstructor: >>>> + if (T.isNonTrivialToPrimitiveDestructiveMove()) >>>> + return false; >>>> // This trait is implemented by MSVC 2012 and needed to parse the >>>> // standard library headers. Specifically this is used as the logic >>>> // behind std::is_trivially_move_constructible (20.9.4.3). >>>> @@ -4533,6 +4537,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> return RD->hasTrivialMoveConstructor() && >>>> !RD->hasNonTrivialMoveConstructor(); >>>> return false; >>>> case UTT_HasTrivialCopy: >>>> + if (T.isNonTrivialToPrimitiveCopy()) >>>> + return false; >>>> // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html >>>> <http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html>: >>>> // If __is_pod (type) is true or type is a reference type then >>>> // the trait is true, else if type is a cv class or union type >>>> @@ -4545,6 +4551,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> !RD->hasNonTrivialCopyConstructor(); >>>> return false; >>>> case UTT_HasTrivialMoveAssign: >>>> + if (T.isNonTrivialToPrimitiveDestructiveMove()) >>>> + return false; >>>> // This trait is implemented by MSVC 2012 and needed to parse the >>>> // standard library headers. Specifically it is used as the logic >>>> // behind std::is_trivially_move_assignable (20.9.4.3) >>>> @@ -4554,6 +4562,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> return RD->hasTrivialMoveAssignment() && >>>> !RD->hasNonTrivialMoveAssignment(); >>>> return false; >>>> case UTT_HasTrivialAssign: >>>> + if (T.isNonTrivialToPrimitiveCopy()) >>>> + return false; >>>> // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html >>>> <http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html>: >>>> // If type is const qualified or is a reference type then the >>>> // trait is false. Otherwise if __is_pod (type) is true then the >>>> @@ -4624,6 +4634,8 @@ static bool EvaluateUnaryTypeTrait(Sema >>>> return true; >>>> >>>> case UTT_HasTrivialDestructor: >>>> + if (T.isDestructedType() == QualType::DK_nontrivial_c_struct) >>>> + return false; >>>> // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html >>>> <http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html> >>>> // If __is_pod (type) is true or type is a reference type >>>> // then the trait is true, else if type is a cv class or union >>>> >>>> Added: cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m >>>> URL: >>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m?rev=328680&view=auto >>>> >>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m?rev=328680&view=auto> >>>> ============================================================================== >>>> --- cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m (added) >>>> +++ cfe/trunk/test/SemaObjC/non-trivial-struct-traits.m Tue Mar 27 >>>> 17:12:08 2018 >>>> @@ -0,0 +1,25 @@ >>>> +// RUN: %clang_cc1 -fsyntax-only -fobjc-arc -verify %s >>>> + >>>> +// expected-no-diagnostics >>>> + >>>> +struct Trivial { >>>> + int x; >>>> +}; >>>> + >>>> +struct NonTrivial { >>>> + id x; >>>> +}; >>>> + >>>> +int trivial_assign[__has_trivial_assign(struct Trivial) ? 1 : -1]; >>>> +int trivial_move_assign[__has_trivial_move_assign(struct Trivial) ? 1 : >>>> -1]; >>>> +int trivial_copy_constructor[__has_trivial_copy(struct Trivial) ? 1 : -1]; >>>> +int trivial_move_constructor[__has_trivial_move_constructor(struct >>>> Trivial) ? 1 : -1]; >>>> +int trivial_constructor[__has_trivial_constructor(struct Trivial) ? 1 : >>>> -1]; >>>> +int trivial_destructor[__has_trivial_destructor(struct Trivial) ? 1 : -1]; >>>> + >>>> +int non_trivial_assign[__has_trivial_assign(struct NonTrivial) ? -1 : 1]; >>>> +int non_trivial_move_assign[__has_trivial_move_assign(struct NonTrivial) >>>> ? -1 : 1]; >>>> +int non_trivial_copy_constructor[__has_trivial_copy(struct NonTrivial) ? >>>> -1 : 1]; >>>> +int non_trivial_move_constructor[__has_trivial_move_constructor(struct >>>> NonTrivial) ? -1 : 1]; >>>> +int non_trivial_constructor[__has_trivial_constructor(struct NonTrivial) >>>> ? -1 : 1]; >>>> +int non_trivial_destructor[__has_trivial_destructor(struct NonTrivial) ? >>>> -1 : 1]; >>>> >>>> >>>> _______________________________________________ >>>> cfe-commits mailing list >>>> cfe-commits@lists.llvm.org <mailto:cfe-commits@lists.llvm.org> >>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >>>> <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits> >>>> >>> >>> _______________________________________________ >>> cfe-commits mailing list >>> cfe-commits@lists.llvm.org <mailto:cfe-commits@lists.llvm.org> >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >>> <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits>
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