diff options
| -rw-r--r-- | include/clang/Basic/DiagnosticASTKinds.td | 28 | ||||
| -rw-r--r-- | lib/AST/ExprConstant.cpp | 28 | ||||
| -rw-r--r-- | test/SemaCXX/constant-expression-cxx2a.cpp | 59 | ||||
| -rwxr-xr-x | www/cxx_status.html | 3 |
4 files changed, 98 insertions, 20 deletions
diff --git a/include/clang/Basic/DiagnosticASTKinds.td b/include/clang/Basic/DiagnosticASTKinds.td index 3e9ebbbabd..a9e88d5ecb 100644 --- a/include/clang/Basic/DiagnosticASTKinds.td +++ b/include/clang/Basic/DiagnosticASTKinds.td @@ -12,7 +12,8 @@ let Component = "AST" in { def note_expr_divide_by_zero : Note<"division by zero">; def note_constexpr_invalid_cast : Note< "%select{reinterpret_cast|dynamic_cast|cast that performs the conversions of" - " a reinterpret_cast|cast from %1}0 is not allowed in a constant expression">; + " a reinterpret_cast|cast from %1}0 is not allowed in a constant expression" + "%select{| in C++ standards before C++2a||}0">; def note_constexpr_invalid_downcast : Note< "cannot cast object of dynamic type %0 to type %1">; def note_constexpr_overflow : Note< @@ -31,12 +32,13 @@ def note_constexpr_invalid_inhctor : Note< def note_constexpr_no_return : Note< "control reached end of constexpr function">; def note_constexpr_virtual_call : Note< - "cannot evaluate call to virtual function in a constant expression">; + "cannot evaluate call to virtual function in a constant expression " + "in C++ standards before C++2a">; def note_constexpr_pure_virtual_call : Note< "pure virtual function %q0 called">; def note_constexpr_polymorphic_unknown_dynamic_type : Note< - "%select{||||virtual function called on|dynamic_cast applied to}0 " - "object '%1' whose dynamic type is not constant">; + "%select{||||virtual function called on|dynamic_cast applied to|" + "typeid applied to}0 object '%1' whose dynamic type is not constant">; def note_constexpr_dynamic_cast_to_reference_failed : Note< "reference dynamic_cast failed: %select{" "static type %1 of operand is a non-public base class of dynamic type %2|" @@ -90,7 +92,7 @@ def note_constexpr_var_init_non_constant : Note< "initializer of %0 is not a constant expression">; def note_constexpr_typeid_polymorphic : Note< "typeid applied to expression of polymorphic type %0 is " - "not allowed in a constant expression">; + "not allowed in a constant expression in C++ standards before C++2a">; def note_constexpr_void_comparison : Note< "comparison between unequal pointers to void has unspecified result">; def note_constexpr_temporary_here : Note<"temporary created here">; @@ -108,11 +110,11 @@ def note_constexpr_this : Note< "evaluation of a call to a 'constexpr' member function">; def note_constexpr_lifetime_ended : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "%select{temporary|variable}1 whose lifetime has ended">; def note_constexpr_access_uninit : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "object outside its lifetime is not allowed in a constant expression">; def note_constexpr_use_uninit_reference : Note< "use of reference outside its lifetime " @@ -139,30 +141,30 @@ def note_constexpr_ltor_incomplete_type : Note< "read of incomplete type %0 is not allowed in a constant expression">; def note_constexpr_access_null : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "dereferenced null pointer is not allowed in a constant expression">; def note_constexpr_access_past_end : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "dereferenced one-past-the-end pointer is not allowed in a constant expression">; def note_constexpr_access_unsized_array : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "element of array without known bound " "is not allowed in a constant expression">; def note_constexpr_access_inactive_union_member : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 " + "dynamic_cast of|typeid applied to}0 " "member %1 of union with %select{active member %3|no active member}2 " "is not allowed in a constant expression">; def note_constexpr_access_static_temporary : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 temporary " + "dynamic_cast of|typeid applied to}0 temporary " "is not allowed in a constant expression outside the expression that " "created the temporary">; def note_constexpr_access_unreadable_object : Note< "%select{read of|assignment to|increment of|decrement of|member call on|" - "dynamic_cast of}0 object '%1' whose value is not known">; + "dynamic_cast of|typeid applied to}0 object '%1' whose value is not known">; def note_constexpr_modify_global : Note< "a constant expression cannot modify an object that is visible outside " "that expression">; diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp index e41264e55e..35000f42b2 100644 --- a/lib/AST/ExprConstant.cpp +++ b/lib/AST/ExprConstant.cpp @@ -1349,6 +1349,7 @@ enum AccessKinds { AK_Decrement, AK_MemberCall, AK_DynamicCast, + AK_TypeId, }; static bool isModification(AccessKinds AK) { @@ -1356,6 +1357,7 @@ static bool isModification(AccessKinds AK) { case AK_Read: case AK_MemberCall: case AK_DynamicCast: + case AK_TypeId: return false; case AK_Assign: case AK_Increment: @@ -6029,19 +6031,33 @@ LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) { } bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) { + TypeInfoLValue TypeInfo; + if (!E->isPotentiallyEvaluated()) { - TypeInfoLValue TypeInfo; if (E->isTypeOperand()) TypeInfo = TypeInfoLValue(E->getTypeOperand(Info.Ctx).getTypePtr()); else TypeInfo = TypeInfoLValue(E->getExprOperand()->getType().getTypePtr()); - return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType())); + } else { + if (!Info.Ctx.getLangOpts().CPlusPlus2a) { + Info.CCEDiag(E, diag::note_constexpr_typeid_polymorphic) + << E->getExprOperand()->getType() + << E->getExprOperand()->getSourceRange(); + } + + if (!Visit(E->getExprOperand())) + return false; + + Optional<DynamicType> DynType = + ComputeDynamicType(Info, E, Result, AK_TypeId); + if (!DynType) + return false; + + TypeInfo = + TypeInfoLValue(Info.Ctx.getRecordType(DynType->Type).getTypePtr()); } - Info.FFDiag(E, diag::note_constexpr_typeid_polymorphic) - << E->getExprOperand()->getType() - << E->getExprOperand()->getSourceRange(); - return false; + return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType())); } bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) { diff --git a/test/SemaCXX/constant-expression-cxx2a.cpp b/test/SemaCXX/constant-expression-cxx2a.cpp index c49d670db3..90980c8d05 100644 --- a/test/SemaCXX/constant-expression-cxx2a.cpp +++ b/test/SemaCXX/constant-expression-cxx2a.cpp @@ -2,6 +2,10 @@ #include "Inputs/std-compare.h" +namespace std { + struct type_info; +}; + namespace ThreeWayComparison { struct A { int n; @@ -354,3 +358,58 @@ namespace DynamicCast { // expected-note@+1 {{reference dynamic_cast failed: dynamic type 'DynamicCast::G' of operand does not have a base class of type 'DynamicCast::Unrelated'}} constexpr int e_unrelated = (dynamic_cast<Unrelated&>((E&)g), 0); // expected-error {{}} } + +namespace TypeId { + struct A { + const std::type_info &ti = typeid(*this); + }; + struct A2 : A {}; + static_assert(&A().ti == &typeid(A)); + static_assert(&typeid((A2())) == &typeid(A2)); + extern A2 extern_a2; + static_assert(&typeid(extern_a2) == &typeid(A2)); + + constexpr A2 a2; + constexpr const A &a1 = a2; + static_assert(&typeid(a1) == &typeid(A)); + + struct B { + virtual void f(); + const std::type_info &ti1 = typeid(*this); + }; + struct B2 : B { + const std::type_info &ti2 = typeid(*this); + }; + static_assert(&B2().ti1 == &typeid(B)); + static_assert(&B2().ti2 == &typeid(B2)); + extern B2 extern_b2; + // expected-note@+1 {{typeid applied to object 'extern_b2' whose dynamic type is not constant}} + static_assert(&typeid(extern_b2) == &typeid(B2)); // expected-error {{constant expression}} + + constexpr B2 b2; + constexpr const B &b1 = b2; + static_assert(&typeid(b1) == &typeid(B2)); + + constexpr bool side_effects() { + // Not polymorphic nor a glvalue. + bool OK = true; + (void)typeid(OK = false, A2()); // expected-warning {{has no effect}} + if (!OK) return false; + + // Not polymorphic. + A2 a2; + (void)typeid(OK = false, a2); // expected-warning {{has no effect}} + if (!OK) return false; + + // Not a glvalue. + (void)typeid(OK = false, B2()); // expected-warning {{has no effect}} + if (!OK) return false; + + // Polymorphic glvalue: operand evaluated. + OK = false; + B2 b2; + (void)typeid(OK = true, b2); // expected-warning {{will be evaluated}} + return OK; + } + static_assert(side_effects()); +} diff --git a/www/cxx_status.html b/www/cxx_status.html index 84552c2018..5acdd56391 100755 --- a/www/cxx_status.html +++ b/www/cxx_status.html @@ -973,10 +973,11 @@ as the draft C++2a standard evolves. </tr> <tr> <td><a href="http://wg21.link/p1327r1">P1327R1</a></td> - <td rowspan=2 class="none" align="center">No</td> + <td class="svn" align="center">SVN</td> </tr> <tr> <td><a href="http://wg21.link/p1330r0">P1330R0</a></td> + <td class="none" align="center">No</td> </tr> <tr> <td>Prohibit aggregates with user-declared constructors</td> |