From 222e2a7620e6520ffaf4fc4e69d79c18da31542e Mon Sep 17 00:00:00 2001 From: "Zancanaro; Carlo" Date: Mon, 24 Sep 2012 09:58:17 +1000 Subject: Add the clang library to the repo (with some of my changes, too). --- clang/test/CXX/expr/expr.const/p2-0x.cpp | 596 +++++++++++++++++++++++++++++++ 1 file changed, 596 insertions(+) create mode 100644 clang/test/CXX/expr/expr.const/p2-0x.cpp (limited to 'clang/test/CXX/expr/expr.const/p2-0x.cpp') diff --git a/clang/test/CXX/expr/expr.const/p2-0x.cpp b/clang/test/CXX/expr/expr.const/p2-0x.cpp new file mode 100644 index 0000000..054669e --- /dev/null +++ b/clang/test/CXX/expr/expr.const/p2-0x.cpp @@ -0,0 +1,596 @@ +// RUN: %clang_cc1 -fsyntax-only -std=c++11 -pedantic -verify -fcxx-exceptions %s -fconstexpr-depth 128 -triple i686-pc-linux-gnu + +// A conditional-expression is a core constant expression unless it involves one +// of the following as a potentially evaluated subexpression [...]: + +// - this (5.1.1 [expr.prim.general]) [Note: when evaluating a constant +// expression, function invocation substitution (7.1.5 [dcl.constexpr]) +// replaces each occurrence of this in a constexpr member function with a +// pointer to the class object. -end note]; +struct This { + int this1 : this1; // expected-error {{undeclared}} + int this2 : this->this1; // expected-error {{invalid}} + void this3() { + int n1[this->this1]; // expected-warning {{variable length array}} + int n2[this1]; // expected-warning {{variable length array}} + (void)n1, (void)n2; + } +}; + +// - an invocation of a function other than a constexpr constructor for a +// literal class or a constexpr function [ Note: Overload resolution (13.3) +// is applied as usual - end note ]; +struct NonConstexpr1 { + static int f() { return 1; } // expected-note {{here}} + int n : f(); // expected-error {{constant expression}} expected-note {{non-constexpr function 'f' cannot be used in a constant expression}} +}; +struct NonConstexpr2 { + constexpr NonConstexpr2(); // expected-note {{here}} + int n; +}; +struct NonConstexpr3 { + NonConstexpr3(); + int m : NonConstexpr2().n; // expected-error {{constant expression}} expected-note {{undefined constructor 'NonConstexpr2'}} +}; +struct NonConstexpr4 { + NonConstexpr4(); // expected-note {{declared here}} + int n; +}; +struct NonConstexpr5 { + int n : NonConstexpr4().n; // expected-error {{constant expression}} expected-note {{non-constexpr constructor 'NonConstexpr4' cannot be used in a constant expression}} +}; + +// - an invocation of an undefined constexpr function or an undefined +// constexpr constructor; +struct UndefinedConstexpr { + constexpr UndefinedConstexpr(); + static constexpr int undefinedConstexpr1(); // expected-note {{here}} + int undefinedConstexpr2 : undefinedConstexpr1(); // expected-error {{constant expression}} expected-note {{undefined function 'undefinedConstexpr1' cannot be used in a constant expression}} +}; + +// - an invocation of a constexpr function with arguments that, when substituted +// by function invocation substitution (7.1.5), do not produce a core constant +// expression; +namespace NonConstExprReturn { + static constexpr const int &id_ref(const int &n) { + return n; + } + struct NonConstExprFunction { + int n : id_ref(16); // ok + }; + constexpr const int *address_of(const int &a) { + return &a; + } + constexpr const int *return_param(int n) { // expected-note {{declared here}} + return address_of(n); + } + struct S { + int n : *return_param(0); // expected-error {{constant expression}} expected-note {{read of variable whose lifetime has ended}} + }; +} + +// - an invocation of a constexpr constructor with arguments that, when +// substituted by function invocation substitution (7.1.5), do not produce all +// constant expressions for the constructor calls and full-expressions in the +// mem-initializers (including conversions); +namespace NonConstExprCtor { + struct T { + constexpr T(const int &r) : + r(r) { + } + const int &r; + }; + constexpr int n = 0; + constexpr T t1(n); // ok + constexpr T t2(0); // expected-error {{must be initialized by a constant expression}} expected-note {{temporary created here}} expected-note {{reference to temporary is not a constant expression}} + + struct S { + int n : T(4).r; // ok + }; +} + +// - an invocation of a constexpr function or a constexpr constructor that would +// exceed the implementation-defined recursion limits (see Annex B); +namespace RecursionLimits { + constexpr int RecurseForever(int n) { + return n + RecurseForever(n+1); // expected-note {{constexpr evaluation exceeded maximum depth of 128 calls}} expected-note 9{{in call to 'RecurseForever(}} expected-note {{skipping 118 calls}} + } + struct AlsoRecurseForever { + constexpr AlsoRecurseForever(int n) : + n(AlsoRecurseForever(n+1).n) // expected-note {{constexpr evaluation exceeded maximum depth of 128 calls}} expected-note 9{{in call to 'AlsoRecurseForever(}} expected-note {{skipping 118 calls}} + {} + int n; + }; + struct S { + int k : RecurseForever(0); // expected-error {{constant expression}} expected-note {{in call to}} + int l : AlsoRecurseForever(0).n; // expected-error {{constant expression}} expected-note {{in call to}} + }; +} + +// DR1458: taking the address of an object of incomplete class type +namespace IncompleteClassTypeAddr { + struct S; + extern S s; + constexpr S *p = &s; // ok + static_assert(p, ""); + + extern S sArr[]; + constexpr S (*p2)[] = &sArr; // ok + + struct S { + constexpr S *operator&() { return nullptr; } + }; + constexpr S *q = &s; // ok + static_assert(!q, ""); +} + +// - an operation that would have undefined behavior [Note: including, for +// example, signed integer overflow (Clause 5 [expr]), certain pointer +// arithmetic (5.7 [expr.add]), division by zero (5.6 [expr.mul]), or certain +// shift operations (5.8 [expr.shift]) -end note]; +namespace UndefinedBehavior { + void f(int n) { + switch (n) { + case (int)4.4e9: // expected-error {{constant expression}} expected-note {{value 4.4E+9 is outside the range of representable values of type 'int'}} + case (int)0x80000000u: // ok + case (int)10000000000ll: // expected-note {{here}} + case (unsigned int)10000000000ll: // expected-error {{duplicate case value}} + case (int)(unsigned)(long long)4.4e9: // ok + case (int)(float)1e300: // expected-error {{constant expression}} expected-note {{value 1.0E+300 is outside the range of representable values of type 'float'}} + case (int)((float)1e37 / 1e30): // ok + case (int)(__fp16)65536: // expected-error {{constant expression}} expected-note {{value 65536 is outside the range of representable values of type 'half'}} + break; + } + } + + constexpr int int_min = ~0x7fffffff; + constexpr int minus_int_min = -int_min; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}} + constexpr int div0 = 3 / 0; // expected-error {{constant expression}} expected-note {{division by zero}} expected-warning {{undefined}} + constexpr int mod0 = 3 % 0; // expected-error {{constant expression}} expected-note {{division by zero}} expected-warning {{undefined}} + constexpr int int_min_div_minus_1 = int_min / -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}} + constexpr int int_min_mod_minus_1 = int_min % -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}} + + constexpr int shl_m1 = 0 << -1; // expected-error {{constant expression}} expected-note {{negative shift count -1}} expected-warning {{negative}} + constexpr int shl_0 = 0 << 0; // ok + constexpr int shl_31 = 0 << 31; // ok + constexpr int shl_32 = 0 << 32; // expected-error {{constant expression}} expected-note {{shift count 32 >= width of type 'int' (32}} expected-warning {{>= width of type}} + constexpr int shl_unsigned_negative = unsigned(-3) << 1; // ok + constexpr int shl_unsigned_into_sign = 1u << 31; // ok + constexpr int shl_unsigned_overflow = 1024u << 31; // ok + constexpr int shl_signed_negative = (-3) << 1; // expected-error {{constant expression}} expected-note {{left shift of negative value -3}} + constexpr int shl_signed_ok = 1 << 30; // ok + constexpr int shl_signed_into_sign = 1 << 31; // ok (DR1457) + constexpr int shl_signed_into_sign_2 = 0x7fffffff << 1; // ok (DR1457) + constexpr int shl_signed_off_end = 2 << 31; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{signed shift result (0x100000000) requires 34 bits to represent, but 'int' only has 32 bits}} + constexpr int shl_signed_off_end_2 = 0x7fffffff << 2; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{signed shift result (0x1FFFFFFFC) requires 34 bits to represent, but 'int' only has 32 bits}} + constexpr int shl_signed_overflow = 1024 << 31; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{requires 43 bits to represent}} + constexpr int shl_signed_ok2 = 1024 << 20; // ok + + constexpr int shr_m1 = 0 >> -1; // expected-error {{constant expression}} expected-note {{negative shift count -1}} expected-warning {{negative}} + constexpr int shr_0 = 0 >> 0; // ok + constexpr int shr_31 = 0 >> 31; // ok + constexpr int shr_32 = 0 >> 32; // expected-error {{constant expression}} expected-note {{shift count 32 >= width of type}} expected-warning {{>= width of type}} + + struct S { + int m; + }; + constexpr S s = { 5 }; + constexpr const int *p = &s.m + 1; + constexpr const int &f(const int *q) { + return q[0]; + } + constexpr int n = (f(p), 0); // ok + struct T { + int n : f(p); // expected-error {{not an integral constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}} + }; + + namespace Ptr { + struct A {}; + struct B : A { int n; }; + B a[3][3]; + constexpr B *p = a[0] + 4; // expected-error {{constant expression}} expected-note {{element 4 of array of 3 elements}} + B b = {}; + constexpr A *pa = &b + 1; // expected-error {{constant expression}} expected-note {{base class of pointer past the end}} + constexpr B *pb = (B*)((A*)&b + 1); // expected-error {{constant expression}} expected-note {{derived class of pointer past the end}} + constexpr const int *pn = &(&b + 1)->n; // expected-error {{constant expression}} expected-note {{field of pointer past the end}} + constexpr B *parr = &a[3][0]; // expected-error {{constant expression}} expected-note {{array element of pointer past the end}} + + constexpr A *na = nullptr; + constexpr B *nb = nullptr; + constexpr A &ra = *nb; // expected-error {{constant expression}} expected-note {{cannot access base class of null pointer}} + constexpr B &rb = (B&)*na; // expected-error {{constant expression}} expected-note {{cannot access derived class of null pointer}} + static_assert((A*)nb == 0, ""); + static_assert((B*)na == 0, ""); + constexpr const int &nf = nb->n; // expected-error {{constant expression}} expected-note {{cannot access field of null pointer}} + constexpr const int &np = (*(int(*)[4])nullptr)[2]; // expected-error {{constant expression}} expected-note {{cannot access array element of null pointer}} + + struct C { + constexpr int f() { return 0; } + } constexpr c = C(); + constexpr int k1 = c.f(); // ok + constexpr int k2 = ((C*)nullptr)->f(); // expected-error {{constant expression}} expected-note {{cannot call member function on null pointer}} + constexpr int k3 = (&c)[1].f(); // expected-error {{constant expression}} expected-note {{cannot call member function on pointer past the end of object}} + C c2; + constexpr int k4 = c2.f(); // ok! + + constexpr int diff1 = &a[2] - &a[0]; + constexpr int diff2 = &a[1][3] - &a[1][0]; + constexpr int diff3 = &a[2][0] - &a[1][0]; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}} + static_assert(&a[2][0] == &a[1][3], ""); + constexpr int diff4 = (&b + 1) - &b; + constexpr int diff5 = &a[1][2].n - &a[1][0].n; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}} + constexpr int diff6 = &a[1][2].n - &a[1][2].n; + constexpr int diff7 = (A*)&a[0][1] - (A*)&a[0][0]; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}} + } + + namespace Overflow { + // Signed int overflow. + constexpr int n1 = 2 * 3 * 3 * 7 * 11 * 31 * 151 * 331; // ok + constexpr int n2 = 65536 * 32768; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }} + constexpr int n3 = n1 + 1; // ok + constexpr int n4 = n3 + 1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }} + constexpr int n5 = -65536 * 32768; // ok + constexpr int n6 = 3 * -715827883; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }} + constexpr int n7 = -n3 + -1; // ok + constexpr int n8 = -1 + n7; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }} + constexpr int n9 = n3 - 0; // ok + constexpr int n10 = n3 - -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }} + constexpr int n11 = -1 - n3; // ok + constexpr int n12 = -2 - n3; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }} + constexpr int n13 = n5 + n5; // expected-error {{constant expression}} expected-note {{value -4294967296 is outside the range of }} + constexpr int n14 = n3 - n5; // expected-error {{constant expression}} expected-note {{value 4294967295 is outside the range of }} + constexpr int n15 = n5 * n5; // expected-error {{constant expression}} expected-note {{value 4611686018427387904 is outside the range of }} + constexpr signed char c1 = 100 * 2; // ok + constexpr signed char c2 = '\x64' * '\2'; // also ok + constexpr long long ll1 = 0x7fffffffffffffff; // ok + constexpr long long ll2 = ll1 + 1; // expected-error {{constant}} expected-note {{ 9223372036854775808 }} + constexpr long long ll3 = -ll1 - 1; // ok + constexpr long long ll4 = ll3 - 1; // expected-error {{constant}} expected-note {{ -9223372036854775809 }} + constexpr long long ll5 = ll3 * ll3; // expected-error {{constant}} expected-note {{ 85070591730234615865843651857942052864 }} + + // Yikes. + char melchizedek[2200000000]; + typedef decltype(melchizedek[1] - melchizedek[0]) ptrdiff_t; + constexpr ptrdiff_t d1 = &melchizedek[0x7fffffff] - &melchizedek[0]; // ok + constexpr ptrdiff_t d2 = &melchizedek[0x80000000u] - &melchizedek[0]; // expected-error {{constant expression}} expected-note {{ 2147483648 }} + constexpr ptrdiff_t d3 = &melchizedek[0] - &melchizedek[0x80000000u]; // ok + constexpr ptrdiff_t d4 = &melchizedek[0] - &melchizedek[0x80000001u]; // expected-error {{constant expression}} expected-note {{ -2147483649 }} + + // Unsigned int overflow. + static_assert(65536u * 65536u == 0u, ""); // ok + static_assert(4294967295u + 1u == 0u, ""); // ok + static_assert(0u - 1u == 4294967295u, ""); // ok + static_assert(~0u * ~0u == 1u, ""); // ok + + // Floating-point overflow and NaN. + constexpr float f1 = 1e38f * 3.4028f; // ok + constexpr float f2 = 1e38f * 3.4029f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}} + constexpr float f3 = 1e38f / -.2939f; // ok + constexpr float f4 = 1e38f / -.2938f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}} + constexpr float f5 = 2e38f + 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}} + constexpr float f6 = -2e38f - 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}} + constexpr float f7 = 0.f / 0.f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces a NaN}} + } +} + +// - a lambda-expression (5.1.2); +struct Lambda { + // FIXME: clang crashes when trying to parse this! Revisit this check once + // lambdas are fully implemented. + //int n : []{ return 1; }(); +}; + +// - an lvalue-to-rvalue conversion (4.1) unless it is applied to +namespace LValueToRValue { + // - a non-volatile glvalue of integral or enumeration type that refers to a + // non-volatile const object with a preceding initialization, initialized + // with a constant expression [Note: a string literal (2.14.5 [lex.string]) + // corresponds to an array of such objects. -end note], or + volatile const int vi = 1; // expected-note 2{{here}} + const int ci = 1; + volatile const int &vrci = ci; + static_assert(vi, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} + static_assert(const_cast(vi), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}} + static_assert(vrci, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} + + // - a non-volatile glvalue of literal type that refers to a non-volatile + // object defined with constexpr, or that refers to a sub-object of such an + // object, or + struct V { + constexpr V() : v(1) {} + volatile int v; // expected-note {{not literal because}} + }; + constexpr V v; // expected-error {{non-literal type}} + struct S { + constexpr S(int=0) : i(1), v(const_cast(vi)) {} + constexpr S(const S &s) : i(2), v(const_cast(vi)) {} + int i; + volatile int &v; + }; + constexpr S s; // ok + constexpr volatile S vs; // expected-note {{here}} + constexpr const volatile S &vrs = s; // ok + static_assert(s.i, ""); + static_assert(s.v, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} + static_assert(const_cast(s.v), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}} + static_assert(vs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} + static_assert(const_cast(vs.i), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vs'}} + static_assert(vrs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} + + // - a non-volatile glvalue of literal type that refers to a non-volatile + // temporary object whose lifetime has not ended, initialized with a + // constant expression; + constexpr volatile S f() { return S(); } + static_assert(f().i, ""); // ok! there's no lvalue-to-rvalue conversion here! + static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} +} + +// DR1312: The proposed wording for this defect has issues, so we ignore this +// bullet and instead prohibit casts from pointers to cv void (see core-20842 +// and core-20845). +// +// - an lvalue-to-rvalue conversion (4.1 [conv.lval]) that is applied to a +// glvalue of type cv1 T that refers to an object of type cv2 U, where T and U +// are neither the same type nor similar types (4.4 [conv.qual]); + +// - an lvalue-to-rvalue conversion (4.1) that is applied to a glvalue that +// refers to a non-active member of a union or a subobject thereof; +namespace LValueToRValueUnion { + // test/SemaCXX/constant-expression-cxx11.cpp contains more thorough testing + // of this. + union U { int a, b; } constexpr u = U(); + static_assert(u.a == 0, ""); + constexpr const int *bp = &u.b; + constexpr int b = *bp; // expected-error {{constant expression}} expected-note {{read of member 'b' of union with active member 'a'}} + + extern const U pu; + constexpr const int *pua = &pu.a; + constexpr const int *pub = &pu.b; + constexpr U pu = { .b = 1 }; // expected-warning {{C99 feature}} + constexpr const int a2 = *pua; // expected-error {{constant expression}} expected-note {{read of member 'a' of union with active member 'b'}} + constexpr const int b2 = *pub; // ok +} + +// - an id-expression that refers to a variable or data member of reference type +// unless the reference has a preceding initialization, initialized with a +// constant expression; +namespace References { + const int a = 2; + int &b = *const_cast(&a); + int c = 10; // expected-note 2 {{here}} + int &d = c; + constexpr int e = 42; + int &f = const_cast(e); + extern int &g; + constexpr int &h(); // expected-note {{here}} + int &i = h(); // expected-note {{here}} + constexpr int &j() { return b; } + int &k = j(); + + struct S { + int A : a; + int B : b; + int C : c; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}} + int D : d; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}} + int D2 : &d - &c + 1; + int E : e / 2; + int F : f - 11; + int G : g; // expected-error {{constant expression}} + int H : h(); // expected-error {{constant expression}} expected-note {{undefined function 'h'}} + int I : i; // expected-error {{constant expression}} expected-note {{initializer of 'i' is not a constant expression}} + int J : j(); + int K : k; + }; +} + +// - a dynamic_cast (5.2.7); +namespace DynamicCast { + struct S { int n; }; + constexpr S s { 16 }; + struct T { + int n : dynamic_cast(&s)->n; // expected-warning {{constant expression}} expected-note {{dynamic_cast}} + }; +} + +// - a reinterpret_cast (5.2.10); +namespace ReinterpretCast { + struct S { int n; }; + constexpr S s { 16 }; + struct T { + int n : reinterpret_cast(&s)->n; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}} + }; + struct U { + int m : (long)(S*)6; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}} + }; +} + +// - a pseudo-destructor call (5.2.4); +namespace PseudoDtor { + int k; + typedef int I; + struct T { + int n : (k.~I(), 0); // expected-error {{constant expression}} + }; +} + +// - increment or decrement operations (5.2.6, 5.3.2); +namespace IncDec { + int k = 2; + struct T { + int n : ++k; // expected-error {{constant expression}} + int m : --k; // expected-error {{constant expression}} + }; +} + +// - a typeid expression (5.2.8) whose operand is of a polymorphic class type; +namespace std { + struct type_info { + virtual ~type_info(); + const char *name; + }; +} +namespace TypeId { + struct S { virtual void f(); }; + constexpr S *p = 0; + constexpr const std::type_info &ti1 = typeid(*p); // expected-error {{must be initialized by a constant expression}} expected-note {{typeid applied to expression of polymorphic type 'TypeId::S'}} + + struct T {} t; + constexpr const std::type_info &ti2 = typeid(t); +} + +// - a new-expression (5.3.4); +// - a delete-expression (5.3.5); +namespace NewDelete { + int *p = 0; + struct T { + int n : *new int(4); // expected-error {{constant expression}} + int m : (delete p, 2); // expected-error {{constant expression}} + }; +} + +// - a relational (5.9) or equality (5.10) operator where the result is +// unspecified; +namespace UnspecifiedRelations { + int a, b; + constexpr int *p = &a, *q = &b; + // C++11 [expr.rel]p2: If two pointers p and q of the same type point to + // different objects that are not members of the same array or to different + // functions, or if only one of them is null, the results of pq, p<=q, + // and p>=q are unspecified. + constexpr bool u1 = p < q; // expected-error {{constant expression}} + constexpr bool u2 = p > q; // expected-error {{constant expression}} + constexpr bool u3 = p <= q; // expected-error {{constant expression}} + constexpr bool u4 = p >= q; // expected-error {{constant expression}} + constexpr bool u5 = p < 0; // expected-error {{constant expression}} + constexpr bool u6 = p <= 0; // expected-error {{constant expression}} + constexpr bool u7 = p > 0; // expected-error {{constant expression}} + constexpr bool u8 = p >= 0; // expected-error {{constant expression}} + constexpr bool u9 = 0 < q; // expected-error {{constant expression}} + constexpr bool u10 = 0 <= q; // expected-error {{constant expression}} + constexpr bool u11 = 0 > q; // expected-error {{constant expression}} + constexpr bool u12 = 0 >= q; // expected-error {{constant expression}} + void f(), g(); + + constexpr void (*pf)() = &f, (*pg)() = &g; + constexpr bool u13 = pf < pg; // expected-error {{constant expression}} + constexpr bool u14 = pf == pg; + + // If two pointers point to non-static data members of the same object with + // different access control, the result is unspecified. + struct A { + public: + constexpr A() : a(0), b(0) {} + int a; + constexpr bool cmp() { return &a < &b; } // expected-error {{constexpr function never produces a constant expression}} expected-note {{comparison of address of fields 'a' and 'b' of 'A' with differing access specifiers (public vs private) has unspecified value}} + private: + int b; + }; + class B { + public: + A a; + constexpr bool cmp() { return &a.a < &b.a; } // expected-error {{constexpr function never produces a constant expression}} expected-note {{comparison of address of fields 'a' and 'b' of 'B' with differing access specifiers (public vs protected) has unspecified value}} + protected: + A b; + }; + + // If two pointers point to different base sub-objects of the same object, or + // one points to a base subobject and the other points to a member, the result + // of the comparison is unspecified. This is not explicitly called out by + // [expr.rel]p2, but is covered by 'Other pointer comparisons are + // unspecified'. + struct C { + int c[2]; + }; + struct D { + int d; + }; + struct E : C, D { + struct Inner { + int f; + } e; + } e; + constexpr bool base1 = &e.c[0] < &e.d; // expected-error {{constant expression}} expected-note {{comparison of addresses of subobjects of different base classes has unspecified value}} + constexpr bool base2 = &e.c[1] < &e.e.f; // expected-error {{constant expression}} expected-note {{comparison of address of base class subobject 'C' of class 'E' to field 'e' has unspecified value}} + constexpr bool base3 = &e.e.f < &e.d; // expected-error {{constant expression}} expected-note {{comparison of address of base class subobject 'D' of class 'E' to field 'e' has unspecified value}} + + // [expr.rel]p3: Pointers to void can be compared [...] if both pointers + // represent the same address or are both the null pointer [...]; otherwise + // the result is unspecified. + struct S { int a, b; } s; + constexpr void *null = 0; + constexpr void *pv = (void*)&s.a; + constexpr void *qv = (void*)&s.b; + constexpr bool v1 = null < 0; + constexpr bool v2 = null < pv; // expected-error {{constant expression}} + constexpr bool v3 = null == pv; // ok + constexpr bool v4 = qv == pv; // ok + constexpr bool v5 = qv >= pv; // expected-error {{constant expression}} expected-note {{unequal pointers to void}} + constexpr bool v6 = qv > null; // expected-error {{constant expression}} + constexpr bool v7 = qv <= (void*)&s.b; // ok + constexpr bool v8 = qv > (void*)&s.a; // expected-error {{constant expression}} expected-note {{unequal pointers to void}} +} + +// - an assignment or a compound assignment (5.17); or +namespace Assignment { + int k; + struct T { + int n : (k = 9); // expected-error {{constant expression}} + int m : (k *= 2); // expected-error {{constant expression}} + }; + + struct Literal { + constexpr Literal(const char *name) : name(name) {} + const char *name; + }; + struct Expr { + constexpr Expr(Literal l) : IsLiteral(true), l(l) {} + bool IsLiteral; + union { + Literal l; + // ... + }; + }; + struct MulEq { + constexpr MulEq(Expr a, Expr b) : LHS(a), RHS(b) {} + Expr LHS; + Expr RHS; + }; + constexpr MulEq operator*=(Expr a, Expr b) { return MulEq(a, b); } + Literal a("a"); + Literal b("b"); + MulEq c = a *= b; // ok +} + +// - a throw-expression (15.1) +namespace Throw { + struct S { + int n : (throw "hello", 10); // expected-error {{constant expression}} + }; +} + +// PR9999 +template +class bitWidthHolding { +public: + static const + unsigned int width = (v == 0 ? 0 : bitWidthHolding<(v >> 1)>::width + 1); +}; + +static const int width=bitWidthHolding<255>::width; + +template +struct always_false { + static const bool value = false; +}; + +template +struct and_or { + static const bool and_value = b && and_or::value>::and_value; + static const bool or_value = !b || and_or::value>::or_value; +}; + +static const bool and_value = and_or::and_value; +static const bool or_value = and_or::or_value; + +static_assert(and_value == false, ""); +static_assert(or_value == true, ""); -- cgit v1.2.3