> On Apr 4, 2018, at 3:38 PM, Richard Smith <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? > 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 > > 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> >
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