diff --git a/clang/lib/Sema/SemaTypeTraits.cpp b/clang/lib/Sema/SemaTypeTraits.cpp index 4dbb2450857e0..bf59bbb87fd8a 100644 --- a/clang/lib/Sema/SemaTypeTraits.cpp +++ b/clang/lib/Sema/SemaTypeTraits.cpp @@ -1725,14 +1725,15 @@ static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, // Build expressions that emulate the effect of declval() and // declval(). - if (LhsT->isObjectType() || LhsT->isFunctionType()) - LhsT = Self.Context.getRValueReferenceType(LhsT); - if (RhsT->isObjectType() || RhsT->isFunctionType()) - RhsT = Self.Context.getRValueReferenceType(RhsT); - OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), - Expr::getValueKindForType(LhsT)); - OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), - Expr::getValueKindForType(RhsT)); + auto createDeclValExpr = [&](QualType Ty) -> OpaqueValueExpr { + if (Ty->isObjectType() || Ty->isFunctionType()) + Ty = Self.Context.getRValueReferenceType(Ty); + return {KeyLoc, Ty.getNonLValueExprType(Self.Context), + Expr::getValueKindForType(Ty)}; + }; + + auto Lhs = createDeclValExpr(LhsT); + auto Rhs = createDeclValExpr(RhsT); // Attempt the assignment in an unevaluated context within a SFINAE // trap at translation unit scope. @@ -1956,6 +1957,7 @@ static std::optional StdNameToTypeTrait(StringRef Name) { TypeTrait::UTT_IsCppTriviallyRelocatable) .Case("is_replaceable", TypeTrait::UTT_IsReplaceable) .Case("is_trivially_copyable", TypeTrait::UTT_IsTriviallyCopyable) + .Case("is_assignable", TypeTrait::BTT_IsAssignable) .Default(std::nullopt); } @@ -2285,6 +2287,32 @@ static void DiagnoseNonTriviallyCopyableReason(Sema &SemaRef, SemaRef.Diag(D->getLocation(), diag::note_defined_here) << D; } +static void DiagnoseNonAssignableReason(Sema &SemaRef, SourceLocation Loc, + QualType T, QualType U) { + const CXXRecordDecl *D = T->getAsCXXRecordDecl(); + + auto createDeclValExpr = [&](QualType Ty) -> OpaqueValueExpr { + if (Ty->isObjectType() || Ty->isFunctionType()) + Ty = SemaRef.Context.getRValueReferenceType(Ty); + return {Loc, Ty.getNonLValueExprType(SemaRef.Context), + Expr::getValueKindForType(Ty)}; + }; + + auto LHS = createDeclValExpr(T); + auto RHS = createDeclValExpr(U); + + EnterExpressionEvaluationContext Unevaluated( + SemaRef, Sema::ExpressionEvaluationContext::Unevaluated); + Sema::ContextRAII TUContext(SemaRef, + SemaRef.Context.getTranslationUnitDecl()); + SemaRef.BuildBinOp(/*S=*/nullptr, Loc, BO_Assign, &LHS, &RHS); + + if (!D || D->isInvalidDecl()) + return; + + SemaRef.Diag(D->getLocation(), diag::note_defined_here) << D; +} + void Sema::DiagnoseTypeTraitDetails(const Expr *E) { E = E->IgnoreParenImpCasts(); if (E->containsErrors()) @@ -2305,6 +2333,9 @@ void Sema::DiagnoseTypeTraitDetails(const Expr *E) { case UTT_IsTriviallyCopyable: DiagnoseNonTriviallyCopyableReason(*this, E->getBeginLoc(), Args[0]); break; + case BTT_IsAssignable: + DiagnoseNonAssignableReason(*this, E->getBeginLoc(), Args[0], Args[1]); + break; default: break; } diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp index 329b611110c1d..33b92326aec21 100644 --- a/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp +++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp @@ -20,6 +20,14 @@ struct is_trivially_copyable { template constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T); + +template +struct is_assignable { + static constexpr bool value = __is_assignable(T, U); +}; + +template +constexpr bool is_assignable_v = __is_assignable(T, U); #endif #ifdef STD2 @@ -44,6 +52,17 @@ using is_trivially_copyable = __details_is_trivially_copyable; template constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T); + +template +struct __details_is_assignable { + static constexpr bool value = __is_assignable(T, U); +}; + +template +using is_assignable = __details_is_assignable; + +template +constexpr bool is_assignable_v = __is_assignable(T, U); #endif @@ -73,6 +92,15 @@ using is_trivially_copyable = __details_is_trivially_copyable; template constexpr bool is_trivially_copyable_v = is_trivially_copyable::value; + +template +struct __details_is_assignable : bool_constant<__is_assignable(T, U)> {}; + +template +using is_assignable = __details_is_assignable; + +template +constexpr bool is_assignable_v = is_assignable::value; #endif } @@ -99,6 +127,14 @@ static_assert(std::is_trivially_copyable_v); // expected-note@-1 {{'int &' is not trivially copyable}} \ // expected-note@-1 {{because it is a reference type}} +static_assert(std::is_assignable::value); + +static_assert(std::is_assignable::value); +// expected-error-re@-1 {{static assertion failed due to requirement 'std::{{.*}}is_assignable::value'}} \ +// expected-error@-1 {{assigning to 'int' from incompatible type 'void'}} +static_assert(std::is_assignable_v); +// expected-error@-1 {{static assertion failed due to requirement 'std::is_assignable_v'}} \ +// expected-error@-1 {{assigning to 'int' from incompatible type 'void'}} namespace test_namespace { using namespace std; @@ -119,6 +155,13 @@ namespace test_namespace { // expected-error@-1 {{static assertion failed due to requirement 'is_trivially_copyable_v'}} \ // expected-note@-1 {{'int &' is not trivially copyable}} \ // expected-note@-1 {{because it is a reference type}} + + static_assert(is_assignable::value); + // expected-error-re@-1 {{static assertion failed due to requirement '{{.*}}is_assignable::value'}} \ + // expected-error@-1 {{assigning to 'int' from incompatible type 'void'}} + static_assert(is_assignable_v); + // expected-error@-1 {{static assertion failed due to requirement 'is_assignable_v'}} \ + // expected-error@-1 {{assigning to 'int' from incompatible type 'void'}} } @@ -139,6 +182,14 @@ concept C2 = std::is_trivially_copyable_v; // #concept4 template void g2(); // #cand4 +template +requires std::is_assignable::value void f4(); // #cand7 + +template +concept C4 = std::is_assignable_v; // #concept8 + +template T> void g4(); // #cand8 + void test() { f(); // expected-error@-1 {{no matching function for call to 'f'}} \ @@ -169,6 +220,19 @@ void test() { // expected-note@#concept4 {{because 'std::is_trivially_copyable_v' evaluated to false}} \ // expected-note@#concept4 {{'int &' is not trivially copyable}} \ // expected-note@#concept4 {{because it is a reference type}} + + f4(); + // expected-error@-1 {{no matching function for call to 'f4'}} \ + // expected-note@#cand7 {{candidate template ignored: constraints not satisfied [with T = int &, U = void]}} \ + // expected-note-re@#cand7 {{because '{{.*}}is_assignable::value' evaluated to false}} \ + // expected-error@#cand7 {{assigning to 'int' from incompatible type 'void'}} + + g4(); + // expected-error@-1 {{no matching function for call to 'g4'}} \ + // expected-note@#cand8 {{candidate template ignored: constraints not satisfied [with T = int &]}} \ + // expected-note@#cand8 {{because 'C4' evaluated to false}} \ + // expected-note@#concept8 {{because 'std::is_assignable_v' evaluated to false}} \ + // expected-error@#concept8 {{assigning to 'int' from incompatible type 'void'}} } } diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp index 5210354a66d43..975174353a2a1 100644 --- a/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp +++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp @@ -488,3 +488,74 @@ static_assert(__is_trivially_copyable(S12)); // expected-note@-1 {{'S12' is not trivially copyable}} \ // expected-note@#tc-S12 {{'S12' defined here}} } + +namespace assignable { +struct S1; +static_assert(__is_assignable(S1&, const S1&)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(assignable::S1 &, const assignable::S1 &)'}} \ +// expected-error@-1 {{no viable overloaded '='}} \ +// expected-note@-1 {{type 'S1' is incomplete}} + +static_assert(__is_assignable(void, int)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(void, int)'}} \ +// expected-error@-1 {{expression is not assignable}} + +static_assert(__is_assignable(int, int)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(int, int)'}} \ +// expected-error@-1 {{expression is not assignable}} + +static_assert(__is_assignable(int*, int)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(int *, int)'}} \ +// expected-error@-1 {{expression is not assignable}} + +static_assert(__is_assignable(int[], int)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(int[], int)'}} \ +// expected-error@-1 {{expression is not assignable}} + +static_assert(__is_assignable(int&, void)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(int &, void)'}} \ +// expected-error@-1 {{assigning to 'int' from incompatible type 'void'}} + +static_assert(__is_assignable(int*&, float*)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(int *&, float *)'}} \ +// expected-error@-1 {{incompatible pointer types assigning to 'int *' from 'float *'}} + +static_assert(__is_assignable(const int&, int)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(const int &, int)'}} \ +// expected-error@-1 {{read-only variable is not assignable}} + +struct S2 {}; // #a-S2 +static_assert(__is_assignable(const S2, S2)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(const assignable::S2, assignable::S2)'}} \ +// expected-error@-1 {{no viable overloaded '='}} \ +// expected-note@#a-S2 {{candidate function (the implicit copy assignment operator) not viable: 'this' argument has type 'const S2', but method is not marked const}} \ +// expected-note@#a-S2 {{candidate function (the implicit move assignment operator) not viable: 'this' argument has type 'const S2', but method is not marked const}} \ +// expected-note@#a-S2 {{'S2' defined here}} + +struct S3 { // #a-S3 + S3& operator=(const S3&) = delete; // #aca-S3 + S3& operator=(S3&&) = delete; // #ama-S3 +}; +static_assert(__is_assignable(S3, const S3&)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(assignable::S3, const assignable::S3 &)'}} \ +// expected-error@-1 {{overload resolution selected deleted operator '='}} \ +// expected-note@#aca-S3 {{candidate function has been explicitly deleted}} \ +// expected-note@#ama-S3 {{candidate function not viable: 1st argument ('const S3') would lose const qualifier}} \ +// expected-note@#a-S3 {{'S3' defined here}} +static_assert(__is_assignable(S3, S3&&)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(assignable::S3, assignable::S3 &&)'}} \ +// expected-error@-1 {{overload resolution selected deleted operator '='}} \ +// expected-note@#aca-S3 {{candidate function has been explicitly deleted}} \ +// expected-note@#ama-S3 {{candidate function has been explicitly deleted}} \ +// expected-note@#a-S3 {{'S3' defined here}} + +class C1 { // #a-C1 + C1& operator=(const C1&) = default; + C1& operator=(C1&&) = default; // #ama-C1 +}; +static_assert(__is_assignable(C1, C1)); +// expected-error@-1 {{static assertion failed due to requirement '__is_assignable(assignable::C1, assignable::C1)'}} \ +// expected-error@-1 {{'operator=' is a private member of 'assignable::C1'}} \ +// expected-note@#ama-C1 {{implicitly declared private here}} \ +// expected-note@#a-C1 {{'C1' defined here}} +}