> On Apr 5, 2018, at 1:25 PM, John McCall <rjmcc...@apple.com> wrote: > > > >> On Apr 5, 2018, at 3:54 PM, Akira Hatanaka <ahatan...@apple.com >> <mailto:ahatan...@apple.com>> wrote: >> >> >>> On Apr 5, 2018, at 12:39 PM, John McCall <rjmcc...@apple.com >>> <mailto: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? > > I think that would be fine. Although it would be nice if we could save the > part of the patch that makes the trait logic sensitive to the type queries > instead of needing to include duplicated checks for __strong, __weak, and > whatever other non-trivial C features we eventually add. >
Reverted r329289 in r329608. I wasn’t sure which part of the patch should be saved. I don’t think we need to check the properties of the types calling the QualType::isNonTrivialTo* functions since we aren’t exposing the type traits to C anymore? > John. > >> >>> 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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