On 4 April 2018 at 16:37, Akira Hatanaka via cfe-commits < cfe-commits@lists.llvm.org> wrote:
> > > On Apr 4, 2018, at 4:24 PM, Akira Hatanaka via cfe-commits < > cfe-commits@lists.llvm.org> wrote: > > > 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) 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 __is_trivially_copy_constructible is a better name than __has_trivial_copy_constructor in C, since C doesn't have constructors :) I'd also like to avoid there being confusion about what the right trait to use is in C and in C++ if possible. > On 27 March 2018 at 17:12, Akira Hatanaka via cfe-commits <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 >> 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 >> >> 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 >> ============================================================ >> ================== >> --- 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 >> ============================================================ >> ================== >> --- 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: >> // 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: >> // 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: >> // 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 >> // 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/Se >> maObjC/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 >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >> > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits > > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits > >
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