| // RUN: %clang_cc1 -fsyntax-only -verify -fcxx-exceptions %s |
| |
| // |
| // Tests for "expression traits" intrinsics such as __is_lvalue_expr. |
| // |
| // For the time being, these tests are written against the 2003 C++ |
| // standard (ISO/IEC 14882:2003 -- see draft at |
| // http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2001/n1316/). |
| // |
| // C++0x has its own, more-refined, idea of lvalues and rvalues. |
| // If/when we need to support those, we'll need to track both |
| // standard documents. |
| |
| #if !__has_feature(cxx_static_assert) |
| # define CONCAT_(X_, Y_) CONCAT1_(X_, Y_) |
| # define CONCAT1_(X_, Y_) X_ ## Y_ |
| |
| // This emulation can be used multiple times on one line (and thus in |
| // a macro), except at class scope |
| # define static_assert(b_, m_) \ |
| typedef int CONCAT_(sa_, __LINE__)[b_ ? 1 : -1] |
| #endif |
| |
| // Tests are broken down according to section of the C++03 standard |
| // (ISO/IEC 14882:2003(E)) |
| |
| // Assertion macros encoding the following two paragraphs |
| // |
| // basic.lval/1 Every expression is either an lvalue or an rvalue. |
| // |
| // expr.prim/5 A parenthesized expression is a primary expression whose type |
| // and value are identical to those of the enclosed expression. The |
| // presence of parentheses does not affect whether the expression is |
| // an lvalue. |
| // |
| // Note: these asserts cannot be made at class scope in C++03. Put |
| // them in a member function instead. |
| #define ASSERT_LVALUE(expr) \ |
| static_assert(__is_lvalue_expr(expr), "should be an lvalue"); \ |
| static_assert(__is_lvalue_expr((expr)), \ |
| "the presence of parentheses should have" \ |
| " no effect on lvalueness (expr.prim/5)"); \ |
| static_assert(!__is_rvalue_expr(expr), "should be an lvalue"); \ |
| static_assert(!__is_rvalue_expr((expr)), \ |
| "the presence of parentheses should have" \ |
| " no effect on lvalueness (expr.prim/5)") |
| |
| #define ASSERT_RVALUE(expr); \ |
| static_assert(__is_rvalue_expr(expr), "should be an rvalue"); \ |
| static_assert(__is_rvalue_expr((expr)), \ |
| "the presence of parentheses should have" \ |
| " no effect on lvalueness (expr.prim/5)"); \ |
| static_assert(!__is_lvalue_expr(expr), "should be an rvalue"); \ |
| static_assert(!__is_lvalue_expr((expr)), \ |
| "the presence of parentheses should have" \ |
| " no effect on lvalueness (expr.prim/5)") |
| |
| enum Enum { Enumerator }; |
| |
| int ReturnInt(); |
| void ReturnVoid(); |
| Enum ReturnEnum(); |
| |
| void basic_lval_5() |
| { |
| // basic.lval/5: The result of calling a function that does not return |
| // a reference is an rvalue. |
| ASSERT_RVALUE(ReturnInt()); |
| ASSERT_RVALUE(ReturnVoid()); |
| ASSERT_RVALUE(ReturnEnum()); |
| } |
| |
| int& ReturnIntReference(); |
| extern Enum& ReturnEnumReference(); |
| |
| void basic_lval_6() |
| { |
| // basic.lval/6: An expression which holds a temporary object resulting |
| // from a cast to a nonreference type is an rvalue (this includes |
| // the explicit creation of an object using functional notation |
| struct IntClass |
| { |
| explicit IntClass(int = 0); |
| IntClass(char const*); |
| operator int() const; |
| }; |
| |
| struct ConvertibleToIntClass |
| { |
| operator IntClass() const; |
| }; |
| |
| ConvertibleToIntClass b; |
| |
| // Make sure even trivial conversions are not detected as lvalues |
| int intLvalue = 0; |
| ASSERT_RVALUE((int)intLvalue); |
| ASSERT_RVALUE((short)intLvalue); |
| ASSERT_RVALUE((long)intLvalue); |
| |
| // Same tests with function-call notation |
| ASSERT_RVALUE(int(intLvalue)); |
| ASSERT_RVALUE(short(intLvalue)); |
| ASSERT_RVALUE(long(intLvalue)); |
| |
| char charLValue = 'x'; |
| ASSERT_RVALUE((signed char)charLValue); |
| ASSERT_RVALUE((unsigned char)charLValue); |
| |
| ASSERT_RVALUE(static_cast<int>(IntClass())); |
| IntClass intClassLValue; |
| ASSERT_RVALUE(static_cast<int>(intClassLValue)); |
| ASSERT_RVALUE(static_cast<IntClass>(ConvertibleToIntClass())); |
| ConvertibleToIntClass convertibleToIntClassLValue; |
| ASSERT_RVALUE(static_cast<IntClass>(convertibleToIntClassLValue)); |
| |
| |
| typedef signed char signed_char; |
| typedef unsigned char unsigned_char; |
| ASSERT_RVALUE(signed_char(charLValue)); |
| ASSERT_RVALUE(unsigned_char(charLValue)); |
| |
| ASSERT_RVALUE(int(IntClass())); |
| ASSERT_RVALUE(int(intClassLValue)); |
| ASSERT_RVALUE(IntClass(ConvertibleToIntClass())); |
| ASSERT_RVALUE(IntClass(convertibleToIntClassLValue)); |
| } |
| |
| void conv_ptr_1() |
| { |
| // conv.ptr/1: A null pointer constant is an integral constant |
| // expression (5.19) rvalue of integer type that evaluates to |
| // zero. |
| ASSERT_RVALUE(0); |
| } |
| |
| void expr_6() |
| { |
| // expr/6: If an expression initially has the type "reference to T" |
| // (8.3.2, 8.5.3), ... the expression is an lvalue. |
| int x = 0; |
| int& referenceToInt = x; |
| ASSERT_LVALUE(referenceToInt); |
| ASSERT_LVALUE(ReturnIntReference()); |
| } |
| |
| void expr_prim_2() |
| { |
| // 5.1/2 A string literal is an lvalue; all other |
| // literals are rvalues. |
| ASSERT_LVALUE("foo"); |
| ASSERT_RVALUE(1); |
| ASSERT_RVALUE(1.2); |
| ASSERT_RVALUE(10UL); |
| } |
| |
| void expr_prim_3() |
| { |
| // 5.1/3: The keyword "this" names a pointer to the object for |
| // which a nonstatic member function (9.3.2) is invoked. ...The |
| // expression is an rvalue. |
| struct ThisTest |
| { |
| void f() { ASSERT_RVALUE(this); } |
| }; |
| } |
| |
| extern int variable; |
| void Function(); |
| |
| struct BaseClass |
| { |
| virtual ~BaseClass(); |
| |
| int BaseNonstaticMemberFunction(); |
| static int BaseStaticMemberFunction(); |
| int baseDataMember; |
| }; |
| |
| struct Class : BaseClass |
| { |
| static void function(); |
| static int variable; |
| |
| template <class T> |
| struct NestedClassTemplate {}; |
| |
| template <class T> // expected-note{{possible target for call}} |
| static int& NestedFuncTemplate() { return variable; } |
| |
| template <class T> |
| int& NestedMemfunTemplate() { return variable; } |
| |
| int operator*() const; |
| |
| template <class T> |
| int operator+(T) const; |
| |
| int NonstaticMemberFunction(); |
| static int StaticMemberFunction(); |
| int dataMember; |
| |
| int& referenceDataMember; |
| static int& staticReferenceDataMember; |
| static int staticNonreferenceDataMember; |
| |
| enum Enum { Enumerator }; |
| |
| operator long() const; |
| |
| Class(); |
| Class(int,int); |
| |
| void expr_prim_4() |
| { |
| // 5.1/4: The operator :: followed by an identifier, a |
| // qualified-id, or an operator-function-id is a primary- |
| // expression. ...The result is an lvalue if the entity is |
| // a function or variable. |
| ASSERT_LVALUE(::Function); // identifier: function |
| ASSERT_LVALUE(::variable); // identifier: variable |
| |
| // the only qualified-id form that can start without "::" (and thus |
| // be legal after "::" ) is |
| // |
| // ::<sub>opt</sub> nested-name-specifier template<sub>opt</sub> unqualified-id |
| ASSERT_LVALUE(::Class::function); // qualified-id: function |
| ASSERT_LVALUE(::Class::variable); // qualified-id: variable |
| |
| // The standard doesn't give a clear answer about whether these |
| // should really be lvalues or rvalues without some surrounding |
| // context that forces them to be interpreted as naming a |
| // particular function template specialization (that situation |
| // doesn't come up in legal pure C++ programs). This language |
| // extension simply rejects them as requiring additional context |
| __is_lvalue_expr(::Class::NestedFuncTemplate); // qualified-id: template \ |
| // expected-error{{reference to overloaded function could not be resolved; did you mean to call it?}} |
| |
| __is_lvalue_expr(::Class::NestedMemfunTemplate); // qualified-id: template \ |
| // expected-error{{reference to non-static member function must be called}} |
| |
| __is_lvalue_expr(::Class::operator+); // operator-function-id: template \ |
| // expected-error{{reference to non-static member function must be called}} |
| |
| //ASSERT_RVALUE(::Class::operator*); // operator-function-id: member function |
| } |
| |
| void expr_prim_7() |
| { |
| // expr.prim/7 An identifier is an id-expression provided it has been |
| // suitably declared (clause 7). [Note: ... ] The type of the |
| // expression is the type of the identifier. The result is the |
| // entity denoted by the identifier. The result is an lvalue if |
| // the entity is a function, variable, or data member... (cont'd) |
| ASSERT_LVALUE(Function); // identifier: function |
| ASSERT_LVALUE(StaticMemberFunction); // identifier: function |
| ASSERT_LVALUE(variable); // identifier: variable |
| ASSERT_LVALUE(dataMember); // identifier: data member |
| //ASSERT_RVALUE(NonstaticMemberFunction); // identifier: member function |
| |
| // (cont'd)...A nested-name-specifier that names a class, |
| // optionally followed by the keyword template (14.2), and then |
| // followed by the name of a member of either that class (9.2) or |
| // one of its base classes... is a qualified-id... The result is |
| // the member. The type of the result is the type of the |
| // member. The result is an lvalue if the member is a static |
| // member function or a data member. |
| ASSERT_LVALUE(Class::dataMember); |
| ASSERT_LVALUE(Class::StaticMemberFunction); |
| //ASSERT_RVALUE(Class::NonstaticMemberFunction); // identifier: member function |
| |
| ASSERT_LVALUE(Class::baseDataMember); |
| ASSERT_LVALUE(Class::BaseStaticMemberFunction); |
| //ASSERT_RVALUE(Class::BaseNonstaticMemberFunction); // identifier: member function |
| } |
| }; |
| |
| void expr_call_10() |
| { |
| // expr.call/10: A function call is an lvalue if and only if the |
| // result type is a reference. This statement is partially |
| // redundant with basic.lval/5 |
| basic_lval_5(); |
| |
| ASSERT_LVALUE(ReturnIntReference()); |
| ASSERT_LVALUE(ReturnEnumReference()); |
| } |
| |
| namespace Namespace |
| { |
| int x; |
| void function(); |
| } |
| |
| void expr_prim_8() |
| { |
| // expr.prim/8 A nested-name-specifier that names a namespace |
| // (7.3), followed by the name of a member of that namespace (or |
| // the name of a member of a namespace made visible by a |
| // using-directive ) is a qualified-id; 3.4.3.2 describes name |
| // lookup for namespace members that appear in qualified-ids. The |
| // result is the member. The type of the result is the type of the |
| // member. The result is an lvalue if the member is a function or |
| // a variable. |
| ASSERT_LVALUE(Namespace::x); |
| ASSERT_LVALUE(Namespace::function); |
| } |
| |
| void expr_sub_1(int* pointer) |
| { |
| // expr.sub/1 A postfix expression followed by an expression in |
| // square brackets is a postfix expression. One of the expressions |
| // shall have the type "pointer to T" and the other shall have |
| // enumeration or integral type. The result is an lvalue of type |
| // "T." |
| ASSERT_LVALUE(pointer[1]); |
| |
| // The expression E1[E2] is identical (by definition) to *((E1)+(E2)). |
| ASSERT_LVALUE(*(pointer+1)); |
| } |
| |
| void expr_type_conv_1() |
| { |
| // expr.type.conv/1 A simple-type-specifier (7.1.5) followed by a |
| // parenthesized expression-list constructs a value of the specified |
| // type given the expression list. ... If the expression list |
| // specifies more than a single value, the type shall be a class with |
| // a suitably declared constructor (8.5, 12.1), and the expression |
| // T(x1, x2, ...) is equivalent in effect to the declaration T t(x1, |
| // x2, ...); for some invented temporary variable t, with the result |
| // being the value of t as an rvalue. |
| ASSERT_RVALUE(Class(2,2)); |
| } |
| |
| void expr_type_conv_2() |
| { |
| // expr.type.conv/2 The expression T(), where T is a |
| // simple-type-specifier (7.1.5.2) for a non-array complete object |
| // type or the (possibly cv-qualified) void type, creates an |
| // rvalue of the specified type, |
| ASSERT_RVALUE(int()); |
| ASSERT_RVALUE(Class()); |
| ASSERT_RVALUE(void()); |
| } |
| |
| |
| void expr_ref_4() |
| { |
| // Applies to expressions of the form E1.E2 |
| |
| // If E2 is declared to have type "reference to T", then E1.E2 is |
| // an lvalue;.... Otherwise, one of the following rules applies. |
| ASSERT_LVALUE(Class().staticReferenceDataMember); |
| ASSERT_LVALUE(Class().referenceDataMember); |
| |
| // - If E2 is a static data member, and the type of E2 is T, then |
| // E1.E2 is an lvalue; ... |
| ASSERT_LVALUE(Class().staticNonreferenceDataMember); |
| ASSERT_LVALUE(Class().staticReferenceDataMember); |
| |
| |
| // - If E2 is a non-static data member, ... If E1 is an lvalue, |
| // then E1.E2 is an lvalue... |
| Class lvalue; |
| ASSERT_LVALUE(lvalue.dataMember); |
| ASSERT_RVALUE(Class().dataMember); |
| |
| // - If E1.E2 refers to a static member function, ... then E1.E2 |
| // is an lvalue |
| ASSERT_LVALUE(Class().StaticMemberFunction); |
| |
| // - Otherwise, if E1.E2 refers to a non-static member function, |
| // then E1.E2 is not an lvalue. |
| //ASSERT_RVALUE(Class().NonstaticMemberFunction); |
| |
| // - If E2 is a member enumerator, and the type of E2 is T, the |
| // expression E1.E2 is not an lvalue. The type of E1.E2 is T. |
| ASSERT_RVALUE(Class().Enumerator); |
| ASSERT_RVALUE(lvalue.Enumerator); |
| } |
| |
| |
| void expr_post_incr_1(int x) |
| { |
| // expr.post.incr/1 The value obtained by applying a postfix ++ is |
| // the value that the operand had before applying the |
| // operator... The result is an rvalue. |
| ASSERT_RVALUE(x++); |
| } |
| |
| void expr_dynamic_cast_2() |
| { |
| // expr.dynamic.cast/2: If T is a pointer type, v shall be an |
| // rvalue of a pointer to complete class type, and the result is |
| // an rvalue of type T. |
| Class instance; |
| ASSERT_RVALUE(dynamic_cast<Class*>(&instance)); |
| |
| // If T is a reference type, v shall be an |
| // lvalue of a complete class type, and the result is an lvalue of |
| // the type referred to by T. |
| ASSERT_LVALUE(dynamic_cast<Class&>(instance)); |
| } |
| |
| void expr_dynamic_cast_5() |
| { |
| // expr.dynamic.cast/5: If T is "reference to cv1 B" and v has type |
| // "cv2 D" such that B is a base class of D, the result is an |
| // lvalue for the unique B sub-object of the D object referred |
| // to by v. |
| typedef BaseClass B; |
| typedef Class D; |
| D object; |
| ASSERT_LVALUE(dynamic_cast<B&>(object)); |
| } |
| |
| // expr.dynamic.cast/8: The run-time check logically executes as follows: |
| // |
| // - If, in the most derived object pointed (referred) to by v, v |
| // points (refers) to a public base class subobject of a T object, and |
| // if only one object of type T is derived from the sub-object pointed |
| // (referred) to by v, the result is a pointer (an lvalue referring) |
| // to that T object. |
| // |
| // - Otherwise, if v points (refers) to a public base class sub-object |
| // of the most derived object, and the type of the most derived object |
| // has a base class, of type T, that is unambiguous and public, the |
| // result is a pointer (an lvalue referring) to the T sub-object of |
| // the most derived object. |
| // |
| // The mention of "lvalue" in the text above appears to be a |
| // defect that is being corrected by the response to UK65 (see |
| // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2841.html). |
| |
| #if 0 |
| void expr_typeid_1() |
| { |
| // expr.typeid/1: The result of a typeid expression is an lvalue... |
| ASSERT_LVALUE(typeid(1)); |
| } |
| #endif |
| |
| void expr_static_cast_1(int x) |
| { |
| // expr.static.cast/1: The result of the expression |
| // static_cast<T>(v) is the result of converting the expression v |
| // to type T. If T is a reference type, the result is an lvalue; |
| // otherwise, the result is an rvalue. |
| ASSERT_LVALUE(static_cast<int&>(x)); |
| ASSERT_RVALUE(static_cast<int>(x)); |
| } |
| |
| void expr_reinterpret_cast_1() |
| { |
| // expr.reinterpret.cast/1: The result of the expression |
| // reinterpret_cast<T>(v) is the result of converting the |
| // expression v to type T. If T is a reference type, the result is |
| // an lvalue; otherwise, the result is an rvalue |
| ASSERT_RVALUE(reinterpret_cast<int*>(0)); |
| char const v = 0; |
| ASSERT_LVALUE(reinterpret_cast<char const&>(v)); |
| } |
| |
| void expr_unary_op_1(int* pointer, struct incomplete* pointerToIncompleteType) |
| { |
| // expr.unary.op/1: The unary * operator performs indirection: the |
| // expression to which it is applied shall be a pointer to an |
| // object type, or a pointer to a function type and the result is |
| // an lvalue referring to the object or function to which the |
| // expression points. |
| ASSERT_LVALUE(*pointer); |
| ASSERT_LVALUE(*Function); |
| |
| // [Note: a pointer to an incomplete type |
| // (other than cv void ) can be dereferenced. ] |
| ASSERT_LVALUE(*pointerToIncompleteType); |
| } |
| |
| void expr_pre_incr_1(int operand) |
| { |
| // expr.pre.incr/1: The operand of prefix ++ ... shall be a |
| // modifiable lvalue.... The value is the new value of the |
| // operand; it is an lvalue. |
| ASSERT_LVALUE(++operand); |
| } |
| |
| void expr_cast_1(int x) |
| { |
| // expr.cast/1: The result of the expression (T) cast-expression |
| // is of type T. The result is an lvalue if T is a reference type, |
| // otherwise the result is an rvalue. |
| ASSERT_LVALUE((void(&)())expr_cast_1); |
| ASSERT_LVALUE((int&)x); |
| ASSERT_RVALUE((void(*)())expr_cast_1); |
| ASSERT_RVALUE((int)x); |
| } |
| |
| void expr_mptr_oper() |
| { |
| // expr.mptr.oper/6: The result of a .* expression is an lvalue |
| // only if its first operand is an lvalue and its second operand |
| // is a pointer to data member... (cont'd) |
| typedef Class MakeRValue; |
| ASSERT_RVALUE(MakeRValue().*(&Class::dataMember)); |
| //ASSERT_RVALUE(MakeRValue().*(&Class::NonstaticMemberFunction)); |
| Class lvalue; |
| ASSERT_LVALUE(lvalue.*(&Class::dataMember)); |
| //ASSERT_RVALUE(lvalue.*(&Class::NonstaticMemberFunction)); |
| |
| // (cont'd)...The result of an ->* expression is an lvalue only |
| // if its second operand is a pointer to data member. If the |
| // second operand is the null pointer to member value (4.11), the |
| // behavior is undefined. |
| ASSERT_LVALUE((&lvalue)->*(&Class::dataMember)); |
| //ASSERT_RVALUE((&lvalue)->*(&Class::NonstaticMemberFunction)); |
| } |
| |
| void expr_cond(bool cond) |
| { |
| // 5.16 Conditional operator [expr.cond] |
| // |
| // 2 If either the second or the third operand has type (possibly |
| // cv-qualified) void, then the lvalue-to-rvalue (4.1), |
| // array-to-pointer (4.2), and function-to-pointer (4.3) standard |
| // conversions are performed on the second and third operands, and one |
| // of the following shall hold: |
| // |
| // - The second or the third operand (but not both) is a |
| // throw-expression (15.1); the result is of the type of the other and |
| // is an rvalue. |
| |
| Class classLvalue; |
| ASSERT_RVALUE(cond ? throw 1 : (void)0); |
| ASSERT_RVALUE(cond ? (void)0 : throw 1); |
| ASSERT_RVALUE(cond ? throw 1 : classLvalue); |
| ASSERT_RVALUE(cond ? classLvalue : throw 1); |
| |
| // - Both the second and the third operands have type void; the result |
| // is of type void and is an rvalue. [Note: this includes the case |
| // where both operands are throw-expressions. ] |
| ASSERT_RVALUE(cond ? (void)1 : (void)0); |
| ASSERT_RVALUE(cond ? throw 1 : throw 0); |
| |
| // expr.cond/4: If the second and third operands are lvalues and |
| // have the same type, the result is of that type and is an |
| // lvalue. |
| ASSERT_LVALUE(cond ? classLvalue : classLvalue); |
| int intLvalue = 0; |
| ASSERT_LVALUE(cond ? intLvalue : intLvalue); |
| |
| // expr.cond/5:Otherwise, the result is an rvalue. |
| typedef Class MakeRValue; |
| ASSERT_RVALUE(cond ? MakeRValue() : classLvalue); |
| ASSERT_RVALUE(cond ? classLvalue : MakeRValue()); |
| ASSERT_RVALUE(cond ? MakeRValue() : MakeRValue()); |
| ASSERT_RVALUE(cond ? classLvalue : intLvalue); |
| ASSERT_RVALUE(cond ? intLvalue : int()); |
| } |
| |
| void expr_ass_1(int x) |
| { |
| // expr.ass/1: There are several assignment operators, all of |
| // which group right-to-left. All require a modifiable lvalue as |
| // their left operand, and the type of an assignment expression is |
| // that of its left operand. The result of the assignment |
| // operation is the value stored in the left operand after the |
| // assignment has taken place; the result is an lvalue. |
| ASSERT_LVALUE(x = 1); |
| ASSERT_LVALUE(x += 1); |
| ASSERT_LVALUE(x -= 1); |
| ASSERT_LVALUE(x *= 1); |
| ASSERT_LVALUE(x /= 1); |
| ASSERT_LVALUE(x %= 1); |
| ASSERT_LVALUE(x ^= 1); |
| ASSERT_LVALUE(x &= 1); |
| ASSERT_LVALUE(x |= 1); |
| } |
| |
| void expr_comma(int x) |
| { |
| // expr.comma: A pair of expressions separated by a comma is |
| // evaluated left-to-right and the value of the left expression is |
| // discarded... result is an lvalue if its right operand is. |
| |
| // Can't use the ASSERT_XXXX macros without adding parens around |
| // the comma expression. |
| static_assert(__is_lvalue_expr(x,x), "expected an lvalue"); |
| static_assert(__is_rvalue_expr(x,1), "expected an rvalue"); |
| static_assert(__is_lvalue_expr(1,x), "expected an lvalue"); |
| static_assert(__is_rvalue_expr(1,1), "expected an rvalue"); |
| } |
| |
| #if 0 |
| template<typename T> void f(); |
| |
| // FIXME These currently fail |
| void expr_fun_lvalue() |
| { |
| ASSERT_LVALUE(&f<int>); |
| } |
| |
| void expr_fun_rvalue() |
| { |
| ASSERT_RVALUE(f<int>); |
| } |
| #endif |
| |
| template <int NonTypeNonReferenceParameter, int& NonTypeReferenceParameter> |
| void check_temp_param_6() |
| { |
| ASSERT_RVALUE(NonTypeNonReferenceParameter); |
| ASSERT_LVALUE(NonTypeReferenceParameter); |
| } |
| |
| int AnInt = 0; |
| |
| void temp_param_6() |
| { |
| check_temp_param_6<3,AnInt>(); |
| } |