| // RUN: %clang_cc1 -triple x86_64-linux -Wno-string-plus-int -Wno-pointer-arith -Wno-zero-length-array -fsyntax-only -fcxx-exceptions -verify -std=c++11 -pedantic %s -Wno-comment -Wno-tautological-pointer-compare -Wno-bool-conversion |
| |
| namespace StaticAssertFoldTest { |
| |
| int x; |
| static_assert(++x, "test"); // expected-error {{not an integral constant expression}} |
| static_assert(false, "test"); // expected-error {{test}} |
| |
| } |
| |
| typedef decltype(sizeof(char)) size_t; |
| |
| template<typename T> constexpr T id(const T &t) { return t; } |
| template<typename T> constexpr T min(const T &a, const T &b) { |
| return a < b ? a : b; |
| } |
| template<typename T> constexpr T max(const T &a, const T &b) { |
| return a < b ? b : a; |
| } |
| template<typename T, size_t N> constexpr T *begin(T (&xs)[N]) { return xs; } |
| template<typename T, size_t N> constexpr T *end(T (&xs)[N]) { return xs + N; } |
| |
| struct MemberZero { |
| constexpr int zero() const { return 0; } |
| }; |
| |
| namespace DerivedToVBaseCast { |
| |
| struct U { int n; }; |
| struct V : U { int n; }; |
| struct A : virtual V { int n; }; |
| struct Aa { int n; }; |
| struct B : virtual A, Aa {}; |
| struct C : virtual A, Aa {}; |
| struct D : B, C {}; |
| |
| D d; |
| constexpr B *p = &d; |
| constexpr C *q = &d; |
| |
| static_assert((void*)p != (void*)q, ""); |
| static_assert((A*)p == (A*)q, ""); |
| static_assert((Aa*)p != (Aa*)q, ""); |
| |
| constexpr B &pp = d; |
| constexpr C &qq = d; |
| static_assert((void*)&pp != (void*)&qq, ""); |
| static_assert(&(A&)pp == &(A&)qq, ""); |
| static_assert(&(Aa&)pp != &(Aa&)qq, ""); |
| |
| constexpr V *v = p; |
| constexpr V *w = q; |
| constexpr V *x = (A*)p; |
| static_assert(v == w, ""); |
| static_assert(v == x, ""); |
| |
| static_assert((U*)&d == p, ""); |
| static_assert((U*)&d == q, ""); |
| static_assert((U*)&d == v, ""); |
| static_assert((U*)&d == w, ""); |
| static_assert((U*)&d == x, ""); |
| |
| struct X {}; |
| struct Y1 : virtual X {}; |
| struct Y2 : X {}; |
| struct Z : Y1, Y2 {}; |
| Z z; |
| static_assert((X*)(Y1*)&z != (X*)(Y2*)&z, ""); |
| } |
| |
| namespace ConstCast { |
| |
| constexpr int n1 = 0; |
| constexpr int n2 = const_cast<int&>(n1); |
| constexpr int *n3 = const_cast<int*>(&n1); |
| constexpr int n4 = *const_cast<int*>(&n1); |
| constexpr const int * const *n5 = const_cast<const int* const*>(&n3); |
| constexpr int **n6 = const_cast<int**>(&n3); |
| constexpr int n7 = **n5; |
| constexpr int n8 = **n6; |
| |
| // const_cast from prvalue to xvalue. |
| struct A { int n; }; |
| constexpr int n9 = (const_cast<A&&>(A{123})).n; |
| static_assert(n9 == 123, ""); |
| |
| } |
| |
| namespace TemplateArgumentConversion { |
| template<int n> struct IntParam {}; |
| |
| using IntParam0 = IntParam<0>; |
| using IntParam0 = IntParam<id(0)>; |
| using IntParam0 = IntParam<MemberZero().zero>; // expected-error {{did you mean to call it with no arguments?}} |
| } |
| |
| namespace CaseStatements { |
| int x; |
| void f(int n) { |
| switch (n) { |
| case MemberZero().zero: // expected-error {{did you mean to call it with no arguments?}} expected-note {{previous}} |
| case id(0): // expected-error {{duplicate case value '0'}} |
| return; |
| case __builtin_constant_p(true) ? (__SIZE_TYPE__)&x : 0:; // expected-error {{constant}} |
| } |
| } |
| } |
| |
| extern int &Recurse1; |
| int &Recurse2 = Recurse1; // expected-note {{declared here}} |
| int &Recurse1 = Recurse2; |
| constexpr int &Recurse3 = Recurse2; // expected-error {{must be initialized by a constant expression}} expected-note {{initializer of 'Recurse2' is not a constant expression}} |
| |
| extern const int RecurseA; |
| const int RecurseB = RecurseA; // expected-note {{declared here}} |
| const int RecurseA = 10; |
| constexpr int RecurseC = RecurseB; // expected-error {{must be initialized by a constant expression}} expected-note {{initializer of 'RecurseB' is not a constant expression}} |
| |
| namespace MemberEnum { |
| struct WithMemberEnum { |
| enum E { A = 42 }; |
| } wme; |
| |
| static_assert(wme.A == 42, ""); |
| } |
| |
| namespace DefaultArguments { |
| |
| const int z = int(); |
| constexpr int Sum(int a = 0, const int &b = 0, const int *c = &z, char d = 0) { |
| return a + b + *c + d; |
| } |
| const int four = 4; |
| constexpr int eight = 8; |
| constexpr const int twentyseven = 27; |
| static_assert(Sum() == 0, ""); |
| static_assert(Sum(1) == 1, ""); |
| static_assert(Sum(1, four) == 5, ""); |
| static_assert(Sum(1, eight, &twentyseven) == 36, ""); |
| static_assert(Sum(1, 2, &four, eight) == 15, ""); |
| |
| } |
| |
| namespace Ellipsis { |
| |
| // Note, values passed through an ellipsis can't actually be used. |
| constexpr int F(int a, ...) { return a; } |
| static_assert(F(0) == 0, ""); |
| static_assert(F(1, 0) == 1, ""); |
| static_assert(F(2, "test") == 2, ""); |
| static_assert(F(3, &F) == 3, ""); |
| int k = 0; // expected-note {{here}} |
| static_assert(F(4, k) == 3, ""); // expected-error {{constant expression}} expected-note {{read of non-const variable 'k'}} |
| |
| } |
| |
| namespace Recursion { |
| constexpr int fib(int n) { return n > 1 ? fib(n-1) + fib(n-2) : n; } |
| static_assert(fib(11) == 89, ""); |
| |
| constexpr int gcd_inner(int a, int b) { |
| return b == 0 ? a : gcd_inner(b, a % b); |
| } |
| constexpr int gcd(int a, int b) { |
| return gcd_inner(max(a, b), min(a, b)); |
| } |
| |
| static_assert(gcd(1749237, 5628959) == 7, ""); |
| } |
| |
| namespace FunctionCast { |
| // When folding, we allow functions to be cast to different types. Such |
| // cast functions cannot be called, even if they're constexpr. |
| constexpr int f() { return 1; } |
| typedef double (*DoubleFn)(); |
| typedef int (*IntFn)(); |
| int a[(int)DoubleFn(f)()]; // expected-error {{variable length array}} expected-warning{{C99 feature}} |
| int b[(int)IntFn(f)()]; // ok |
| } |
| |
| namespace StaticMemberFunction { |
| struct S { |
| static constexpr int k = 42; |
| static constexpr int f(int n) { return n * k + 2; } |
| } s; |
| |
| constexpr int n = s.f(19); |
| static_assert(S::f(19) == 800, ""); |
| static_assert(s.f(19) == 800, ""); |
| static_assert(n == 800, ""); |
| |
| constexpr int (*sf1)(int) = &S::f; |
| constexpr int (*sf2)(int) = &s.f; |
| constexpr const int *sk = &s.k; |
| } |
| |
| namespace ParameterScopes { |
| |
| const int k = 42; |
| constexpr const int &ObscureTheTruth(const int &a) { return a; } |
| constexpr const int &MaybeReturnJunk(bool b, const int a) { // expected-note 2{{declared here}} |
| return ObscureTheTruth(b ? a : k); |
| } |
| static_assert(MaybeReturnJunk(false, 0) == 42, ""); // ok |
| constexpr int a = MaybeReturnJunk(true, 0); // expected-error {{constant expression}} expected-note {{read of variable whose lifetime has ended}} |
| |
| constexpr const int MaybeReturnNonstaticRef(bool b, const int a) { |
| return ObscureTheTruth(b ? a : k); |
| } |
| static_assert(MaybeReturnNonstaticRef(false, 0) == 42, ""); // ok |
| constexpr int b = MaybeReturnNonstaticRef(true, 0); // ok |
| |
| constexpr int InternalReturnJunk(int n) { |
| return MaybeReturnJunk(true, n); // expected-note {{read of variable whose lifetime has ended}} |
| } |
| constexpr int n3 = InternalReturnJunk(0); // expected-error {{must be initialized by a constant expression}} expected-note {{in call to 'InternalReturnJunk(0)'}} |
| |
| constexpr int LToR(int &n) { return n; } |
| constexpr int GrabCallersArgument(bool which, int a, int b) { |
| return LToR(which ? b : a); |
| } |
| static_assert(GrabCallersArgument(false, 1, 2) == 1, ""); |
| static_assert(GrabCallersArgument(true, 4, 8) == 8, ""); |
| |
| } |
| |
| namespace Pointers { |
| |
| constexpr int f(int n, const int *a, const int *b, const int *c) { |
| return n == 0 ? 0 : *a + f(n-1, b, c, a); |
| } |
| |
| const int x = 1, y = 10, z = 100; |
| static_assert(f(23, &x, &y, &z) == 788, ""); |
| |
| constexpr int g(int n, int a, int b, int c) { |
| return f(n, &a, &b, &c); |
| } |
| static_assert(g(23, x, y, z) == 788, ""); |
| |
| } |
| |
| namespace FunctionPointers { |
| |
| constexpr int Double(int n) { return 2 * n; } |
| constexpr int Triple(int n) { return 3 * n; } |
| constexpr int Twice(int (*F)(int), int n) { return F(F(n)); } |
| constexpr int Quadruple(int n) { return Twice(Double, n); } |
| constexpr auto Select(int n) -> int (*)(int) { |
| return n == 2 ? &Double : n == 3 ? &Triple : n == 4 ? &Quadruple : 0; |
| } |
| constexpr int Apply(int (*F)(int), int n) { return F(n); } // expected-note {{subexpression}} |
| |
| static_assert(1 + Apply(Select(4), 5) + Apply(Select(3), 7) == 42, ""); |
| |
| constexpr int Invalid = Apply(Select(0), 0); // expected-error {{must be initialized by a constant expression}} expected-note {{in call to 'Apply(0, 0)'}} |
| |
| } |
| |
| namespace PointerComparison { |
| |
| int x, y; |
| static_assert(&x == &y, "false"); // expected-error {{false}} |
| static_assert(&x != &y, ""); |
| constexpr bool g1 = &x == &y; |
| constexpr bool g2 = &x != &y; |
| constexpr bool g3 = &x <= &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool g4 = &x >= &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool g5 = &x < &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool g6 = &x > &y; // expected-error {{must be initialized by a constant expression}} |
| |
| struct S { int x, y; } s; |
| static_assert(&s.x == &s.y, "false"); // expected-error {{false}} |
| static_assert(&s.x != &s.y, ""); |
| static_assert(&s.x <= &s.y, ""); |
| static_assert(&s.x >= &s.y, "false"); // expected-error {{false}} |
| static_assert(&s.x < &s.y, ""); |
| static_assert(&s.x > &s.y, "false"); // expected-error {{false}} |
| |
| static_assert(0 == &y, "false"); // expected-error {{false}} |
| static_assert(0 != &y, ""); |
| constexpr bool n3 = (int*)0 <= &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n4 = (int*)0 >= &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n5 = (int*)0 < &y; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n6 = (int*)0 > &y; // expected-error {{must be initialized by a constant expression}} |
| |
| static_assert(&x == 0, "false"); // expected-error {{false}} |
| static_assert(&x != 0, ""); |
| constexpr bool n9 = &x <= (int*)0; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n10 = &x >= (int*)0; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n11 = &x < (int*)0; // expected-error {{must be initialized by a constant expression}} |
| constexpr bool n12 = &x > (int*)0; // expected-error {{must be initialized by a constant expression}} |
| |
| static_assert(&x == &x, ""); |
| static_assert(&x != &x, "false"); // expected-error {{false}} |
| static_assert(&x <= &x, ""); |
| static_assert(&x >= &x, ""); |
| static_assert(&x < &x, "false"); // expected-error {{false}} |
| static_assert(&x > &x, "false"); // expected-error {{false}} |
| |
| constexpr S* sptr = &s; |
| constexpr bool dyncast = sptr == dynamic_cast<S*>(sptr); // expected-error {{constant expression}} expected-note {{dynamic_cast}} |
| |
| struct U {}; |
| struct Str { |
| int a : dynamic_cast<S*>(sptr) == dynamic_cast<S*>(sptr); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{dynamic_cast is not allowed in a constant expression}} |
| int b : reinterpret_cast<S*>(sptr) == reinterpret_cast<S*>(sptr); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{reinterpret_cast is not allowed in a constant expression}} |
| int c : (S*)(long)(sptr) == (S*)(long)(sptr); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{cast that performs the conversions of a reinterpret_cast is not allowed in a constant expression}} |
| int d : (S*)(42) == (S*)(42); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{cast that performs the conversions of a reinterpret_cast is not allowed in a constant expression}} |
| int e : (Str*)(sptr) == (Str*)(sptr); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{cast that performs the conversions of a reinterpret_cast is not allowed in a constant expression}} |
| int f : &(U&)(*sptr) == &(U&)(*sptr); // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{cast that performs the conversions of a reinterpret_cast is not allowed in a constant expression}} |
| int g : (S*)(void*)(sptr) == sptr; // \ |
| expected-warning {{not an integral constant expression}} \ |
| expected-note {{cast from 'void *' is not allowed in a constant expression}} |
| }; |
| |
| extern char externalvar[]; |
| constexpr bool constaddress = (void *)externalvar == (void *)0x4000UL; // expected-error {{must be initialized by a constant expression}} expected-note {{reinterpret_cast}} |
| constexpr bool litaddress = "foo" == "foo"; // expected-error {{must be initialized by a constant expression}} |
| static_assert(0 != "foo", ""); |
| |
| } |
| |
| namespace MaterializeTemporary { |
| |
| constexpr int f(const int &r) { return r; } |
| constexpr int n = f(1); |
| |
| constexpr bool same(const int &a, const int &b) { return &a == &b; } |
| constexpr bool sameTemporary(const int &n) { return same(n, n); } |
| |
| static_assert(n, ""); |
| static_assert(!same(4, 4), ""); |
| static_assert(same(n, n), ""); |
| static_assert(sameTemporary(9), ""); |
| |
| struct A { int &&r; }; |
| struct B { A &&a1; A &&a2; }; |
| |
| constexpr B b1 { { 1 }, { 2 } }; // expected-note {{temporary created here}} |
| static_assert(&b1.a1 != &b1.a2, ""); |
| static_assert(&b1.a1.r != &b1.a2.r, ""); // expected-error {{constant expression}} expected-note {{outside the expression that created the temporary}} |
| |
| constexpr B &&b2 { { 3 }, { 4 } }; // expected-note {{temporary created here}} |
| static_assert(&b1 != &b2, ""); |
| static_assert(&b1.a1 != &b2.a1, ""); // expected-error {{constant expression}} expected-note {{outside the expression that created the temporary}} |
| |
| constexpr thread_local B b3 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} |
| void foo() { |
| constexpr static B b1 { { 1 }, { 2 } }; // ok |
| constexpr thread_local B b2 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} |
| constexpr B b3 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} |
| } |
| |
| constexpr B &&b4 = ((1, 2), 3, 4, B { {10}, {{20}} }); |
| static_assert(&b4 != &b2, ""); |
| |
| // Proposed DR: copy-elision doesn't trigger lifetime extension. |
| constexpr B b5 = B{ {0}, {0} }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} |
| |
| namespace NestedNonStatic { |
| // Proposed DR: for a reference constant expression to refer to a static |
| // storage duration temporary, that temporary must itself be initialized |
| // by a constant expression (a core constant expression is not enough). |
| struct A { int &&r; }; |
| struct B { A &&a; }; |
| constexpr B a = { A{0} }; // ok |
| constexpr B b = { A(A{0}) }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} |
| } |
| |
| namespace FakeInitList { |
| struct init_list_3_ints { const int (&x)[3]; }; |
| struct init_list_2_init_list_3_ints { const init_list_3_ints (&x)[2]; }; |
| constexpr init_list_2_init_list_3_ints ils = { { { { 1, 2, 3 } }, { { 4, 5, 6 } } } }; |
| } |
| |
| namespace ConstAddedByReference { |
| const int &r = (0); |
| constexpr int n = r; |
| |
| struct A { constexpr operator int() const { return 0; }}; |
| struct B { constexpr operator const int() const { return 0; }}; |
| const int &ra = A(); |
| const int &rb = B(); |
| constexpr int na = ra; |
| constexpr int nb = rb; |
| } |
| |
| } |
| |
| constexpr int strcmp_ce(const char *p, const char *q) { |
| return (!*p || *p != *q) ? *p - *q : strcmp_ce(p+1, q+1); |
| } |
| |
| namespace StringLiteral { |
| |
| template<typename Char> |
| constexpr int MangleChars(const Char *p) { |
| return *p + 3 * (*p ? MangleChars(p+1) : 0); |
| } |
| |
| static_assert(MangleChars("constexpr!") == 1768383, ""); |
| static_assert(MangleChars(u8"constexpr!") == 1768383, ""); |
| static_assert(MangleChars(L"constexpr!") == 1768383, ""); |
| static_assert(MangleChars(u"constexpr!") == 1768383, ""); |
| static_assert(MangleChars(U"constexpr!") == 1768383, ""); |
| |
| constexpr char c0 = "nought index"[0]; |
| constexpr char c1 = "nice index"[10]; |
| constexpr char c2 = "nasty index"[12]; // expected-error {{must be initialized by a constant expression}} expected-warning {{is past the end}} expected-note {{read of dereferenced one-past-the-end pointer}} |
| constexpr char c3 = "negative index"[-1]; // expected-error {{must be initialized by a constant expression}} expected-warning {{is before the beginning}} expected-note {{cannot refer to element -1 of array of 15 elements}} |
| constexpr char c4 = ((char*)(int*)"no reinterpret_casts allowed")[14]; // expected-error {{must be initialized by a constant expression}} expected-note {{cast that performs the conversions of a reinterpret_cast}} |
| |
| constexpr const char *p = "test" + 2; |
| static_assert(*p == 's', ""); |
| |
| constexpr const char *max_iter(const char *a, const char *b) { |
| return *a < *b ? b : a; |
| } |
| constexpr const char *max_element(const char *a, const char *b) { |
| return (a+1 >= b) ? a : max_iter(a, max_element(a+1, b)); |
| } |
| |
| constexpr char str[] = "the quick brown fox jumped over the lazy dog"; |
| constexpr const char *max = max_element(begin(str), end(str)); |
| static_assert(*max == 'z', ""); |
| static_assert(max == str + 38, ""); |
| |
| static_assert(strcmp_ce("hello world", "hello world") == 0, ""); |
| static_assert(strcmp_ce("hello world", "hello clang") > 0, ""); |
| static_assert(strcmp_ce("constexpr", "test") < 0, ""); |
| static_assert(strcmp_ce("", " ") < 0, ""); |
| |
| struct S { |
| int n : "foo"[4]; // expected-error {{constant expression}} expected-note {{read of dereferenced one-past-the-end pointer is not allowed in a constant expression}} |
| }; |
| |
| struct T { |
| char c[6]; |
| constexpr T() : c{"foo"} {} |
| }; |
| constexpr T t; |
| |
| static_assert(t.c[0] == 'f', ""); |
| static_assert(t.c[1] == 'o', ""); |
| static_assert(t.c[2] == 'o', ""); |
| static_assert(t.c[3] == 0, ""); |
| static_assert(t.c[4] == 0, ""); |
| static_assert(t.c[5] == 0, ""); |
| static_assert(t.c[6] == 0, ""); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| |
| struct U { |
| wchar_t chars[6]; |
| int n; |
| } constexpr u = { { L"test" }, 0 }; |
| static_assert(u.chars[2] == L's', ""); |
| |
| struct V { |
| char c[4]; |
| constexpr V() : c("hi!") {} |
| }; |
| static_assert(V().c[1] == "i"[0], ""); |
| |
| namespace Parens { |
| constexpr unsigned char a[] = ("foo"), b[] = {"foo"}, c[] = {("foo")}, |
| d[4] = ("foo"), e[5] = {"foo"}, f[6] = {("foo")}; |
| static_assert(a[0] == 'f', ""); |
| static_assert(b[1] == 'o', ""); |
| static_assert(c[2] == 'o', ""); |
| static_assert(d[0] == 'f', ""); |
| static_assert(e[1] == 'o', ""); |
| static_assert(f[2] == 'o', ""); |
| static_assert(f[5] == 0, ""); |
| static_assert(f[6] == 0, ""); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| } |
| |
| } |
| |
| namespace Array { |
| |
| template<typename Iter> |
| constexpr auto Sum(Iter begin, Iter end) -> decltype(+*begin) { |
| return begin == end ? 0 : *begin + Sum(begin+1, end); |
| } |
| |
| constexpr int xs[] = { 1, 2, 3, 4, 5 }; |
| constexpr int ys[] = { 5, 4, 3, 2, 1 }; |
| constexpr int sum_xs = Sum(begin(xs), end(xs)); |
| static_assert(sum_xs == 15, ""); |
| |
| constexpr int ZipFoldR(int (*F)(int x, int y, int c), int n, |
| const int *xs, const int *ys, int c) { |
| return n ? F( |
| *xs, // expected-note {{read of dereferenced one-past-the-end pointer}} |
| *ys, |
| ZipFoldR(F, n-1, xs+1, ys+1, c)) // \ |
| expected-note {{in call to 'ZipFoldR(&SubMul, 2, &xs[4], &ys[4], 1)'}} \ |
| expected-note {{in call to 'ZipFoldR(&SubMul, 1, &xs[5], &ys[5], 1)'}} |
| : c; |
| } |
| constexpr int MulAdd(int x, int y, int c) { return x * y + c; } |
| constexpr int InnerProduct = ZipFoldR(MulAdd, 5, xs, ys, 0); |
| static_assert(InnerProduct == 35, ""); |
| |
| constexpr int SubMul(int x, int y, int c) { return (x - y) * c; } |
| constexpr int DiffProd = ZipFoldR(SubMul, 2, xs+3, ys+3, 1); |
| static_assert(DiffProd == 8, ""); |
| static_assert(ZipFoldR(SubMul, 3, xs+3, ys+3, 1), ""); // \ |
| expected-error {{constant expression}} \ |
| expected-note {{in call to 'ZipFoldR(&SubMul, 3, &xs[3], &ys[3], 1)'}} |
| |
| constexpr const int *p = xs + 3; |
| constexpr int xs4 = p[1]; // ok |
| constexpr int xs5 = p[2]; // expected-error {{constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}} |
| constexpr int xs6 = p[3]; // expected-error {{constant expression}} expected-note {{cannot refer to element 6}} |
| constexpr int xs0 = p[-3]; // ok |
| constexpr int xs_1 = p[-4]; // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} |
| |
| constexpr int zs[2][2][2][2] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; // expected-note {{array 'zs' declared here}} |
| static_assert(zs[0][0][0][0] == 1, ""); |
| static_assert(zs[1][1][1][1] == 16, ""); |
| static_assert(zs[0][0][0][2] == 3, ""); // expected-error {{constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}} |
| static_assert((&zs[0][0][0][2])[-1] == 2, ""); |
| static_assert(**(**(zs + 1) + 1) == 11, ""); |
| static_assert(*(&(&(*(*&(&zs[2] - 1)[0] + 2 - 2))[2])[-1][-1] + 1) == 11, ""); // expected-error {{constant expression}} expected-note {{cannot refer to element -1 of array of 2 elements in a constant expression}} |
| static_assert(*(&(&(*(*&(&zs[2] - 1)[0] + 2 - 2))[2])[-1][2] - 2) == 11, ""); |
| constexpr int err_zs_1_2_0_0 = zs[1][2][0][0]; // \ |
| expected-error {{constant expression}} \ |
| expected-note {{cannot access array element of pointer past the end}} \ |
| expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}} |
| |
| constexpr int fail(const int &p) { |
| return (&p)[64]; // expected-note {{cannot refer to element 64 of array of 2 elements}} |
| } |
| static_assert(fail(*(&(&(*(*&(&zs[2] - 1)[0] + 2 - 2))[2])[-1][2] - 2)) == 11, ""); // \ |
| expected-error {{static_assert expression is not an integral constant expression}} \ |
| expected-note {{in call to 'fail(zs[1][0][1][0])'}} |
| |
| constexpr int arr[40] = { 1, 2, 3, [8] = 4 }; // expected-warning {{C99 feature}} |
| constexpr int SumNonzero(const int *p) { |
| return *p + (*p ? SumNonzero(p+1) : 0); |
| } |
| constexpr int CountZero(const int *p, const int *q) { |
| return p == q ? 0 : (*p == 0) + CountZero(p+1, q); |
| } |
| static_assert(SumNonzero(arr) == 6, ""); |
| static_assert(CountZero(arr, arr + 40) == 36, ""); |
| |
| struct ArrayElem { |
| constexpr ArrayElem() : n(0) {} |
| int n; |
| constexpr int f() const { return n; } |
| }; |
| struct ArrayRVal { |
| constexpr ArrayRVal() {} |
| ArrayElem elems[10]; |
| }; |
| static_assert(ArrayRVal().elems[3].f() == 0, ""); |
| |
| namespace CopyCtor { |
| struct A { |
| constexpr A() {} |
| constexpr A(const A &) {} |
| }; |
| struct B { |
| A a; |
| int arr[10]; |
| }; |
| constexpr B b{{}, {1, 2, 3, 4, 5}}; |
| constexpr B c = b; |
| static_assert(c.arr[2] == 3, ""); |
| static_assert(c.arr[7] == 0, ""); |
| } |
| |
| constexpr int selfref[2][2][2] = { |
| selfref[1][1][1] + 1, selfref[0][0][0] + 1, |
| selfref[1][0][1] + 1, selfref[0][1][0] + 1, |
| selfref[1][0][0] + 1, selfref[0][1][1] + 1 }; |
| static_assert(selfref[0][0][0] == 1, ""); |
| static_assert(selfref[0][0][1] == 2, ""); |
| static_assert(selfref[0][1][0] == 1, ""); |
| static_assert(selfref[0][1][1] == 2, ""); |
| static_assert(selfref[1][0][0] == 1, ""); |
| static_assert(selfref[1][0][1] == 3, ""); |
| static_assert(selfref[1][1][0] == 0, ""); |
| static_assert(selfref[1][1][1] == 0, ""); |
| |
| struct TrivialDefCtor { int n; }; |
| typedef TrivialDefCtor TDCArray[2][2]; |
| static_assert(TDCArray{}[1][1].n == 0, ""); |
| |
| struct NonAggregateTDC : TrivialDefCtor {}; |
| typedef NonAggregateTDC NATDCArray[2][2]; |
| static_assert(NATDCArray{}[1][1].n == 0, ""); |
| |
| } |
| |
| // Per current CWG direction, we reject any cases where pointer arithmetic is |
| // not statically known to be valid. |
| namespace ArrayOfUnknownBound { |
| extern int arr[]; |
| constexpr int *a = arr; |
| constexpr int *b = &arr[0]; |
| static_assert(a == b, ""); |
| constexpr int *c = &arr[1]; // expected-error {{constant}} expected-note {{indexing of array without known bound}} |
| constexpr int *d = &a[1]; // expected-error {{constant}} expected-note {{indexing of array without known bound}} |
| constexpr int *e = a + 1; // expected-error {{constant}} expected-note {{indexing of array without known bound}} |
| |
| struct X { |
| int a; |
| int b[]; // expected-warning {{C99}} |
| }; |
| extern X x; |
| constexpr int *xb = x.b; // expected-error {{constant}} expected-note {{not supported}} |
| |
| struct Y { int a; }; |
| extern Y yarr[]; |
| constexpr Y *p = yarr; |
| constexpr int *q = &p->a; |
| |
| extern const int carr[]; // expected-note {{here}} |
| constexpr int n = carr[0]; // expected-error {{constant}} expected-note {{non-constexpr variable}} |
| |
| constexpr int local_extern[] = {1, 2, 3}; |
| void f() { extern const int local_extern[]; } |
| static_assert(local_extern[1] == 2, ""); |
| } |
| |
| namespace DependentValues { |
| |
| struct I { int n; typedef I V[10]; }; |
| I::V x, y; |
| int g(); // expected-note {{declared here}} |
| template<bool B, typename T> struct S : T { |
| int k; |
| void f() { |
| I::V &cells = B ? x : y; |
| I &i = cells[k]; |
| switch (i.n) {} |
| |
| constexpr int n = g(); // expected-error {{must be initialized by a constant expression}} expected-note {{non-constexpr function 'g'}} |
| |
| constexpr int m = this->g(); // ok, could be constexpr |
| } |
| }; |
| |
| extern const int n; |
| template<typename T> void f() { |
| // This is ill-formed, because a hypothetical instantiation at the point of |
| // template definition would be ill-formed due to a construct that does not |
| // depend on a template parameter. |
| constexpr int k = n; // expected-error {{must be initialized by a constant expression}} |
| } |
| // It doesn't matter that the instantiation could later become valid: |
| constexpr int n = 4; |
| template void f<int>(); |
| |
| } |
| |
| namespace Class { |
| |
| struct A { constexpr A(int a, int b) : k(a + b) {} int k; }; |
| constexpr int fn(const A &a) { return a.k; } |
| static_assert(fn(A(4,5)) == 9, ""); |
| |
| struct B { int n; int m; } constexpr b = { 0, b.n }; |
| struct C { |
| constexpr C(C *this_) : m(42), n(this_->m) {} // ok |
| int m, n; |
| }; |
| struct D { |
| C c; |
| constexpr D() : c(&c) {} |
| }; |
| static_assert(D().c.n == 42, ""); |
| |
| struct E { |
| constexpr E() : p(&p) {} |
| void *p; |
| }; |
| constexpr const E &e1 = E(); |
| // This is a constant expression if we elide the copy constructor call, and |
| // is not a constant expression if we don't! But we do, so it is. |
| constexpr E e2 = E(); |
| static_assert(e2.p == &e2.p, ""); |
| constexpr E e3; |
| static_assert(e3.p == &e3.p, ""); |
| |
| extern const class F f; |
| struct F { |
| constexpr F() : p(&f.p) {} |
| const void *p; |
| }; |
| constexpr F f; |
| |
| struct G { |
| struct T { |
| constexpr T(T *p) : u1(), u2(p) {} |
| union U1 { |
| constexpr U1() {} |
| int a, b = 42; |
| } u1; |
| union U2 { |
| constexpr U2(T *p) : c(p->u1.b) {} |
| int c, d; |
| } u2; |
| } t; |
| constexpr G() : t(&t) {} |
| } constexpr g; |
| |
| static_assert(g.t.u1.a == 42, ""); // expected-error {{constant expression}} expected-note {{read of member 'a' of union with active member 'b'}} |
| static_assert(g.t.u1.b == 42, ""); |
| static_assert(g.t.u2.c == 42, ""); |
| static_assert(g.t.u2.d == 42, ""); // expected-error {{constant expression}} expected-note {{read of member 'd' of union with active member 'c'}} |
| |
| struct S { |
| int a, b; |
| const S *p; |
| double d; |
| const char *q; |
| |
| constexpr S(int n, const S *p) : a(5), b(n), p(p), d(n), q("hello") {} |
| }; |
| |
| S global(43, &global); |
| |
| static_assert(S(15, &global).b == 15, ""); |
| |
| constexpr bool CheckS(const S &s) { |
| return s.a == 5 && s.b == 27 && s.p == &global && s.d == 27. && s.q[3] == 'l'; |
| } |
| static_assert(CheckS(S(27, &global)), ""); |
| |
| struct Arr { |
| char arr[3]; |
| constexpr Arr() : arr{'x', 'y', 'z'} {} |
| }; |
| constexpr int hash(Arr &&a) { |
| return a.arr[0] + a.arr[1] * 0x100 + a.arr[2] * 0x10000; |
| } |
| constexpr int k = hash(Arr()); |
| static_assert(k == 0x007a7978, ""); |
| |
| |
| struct AggregateInit { |
| const char &c; |
| int n; |
| double d; |
| int arr[5]; |
| void *p; |
| }; |
| |
| constexpr AggregateInit agg1 = { "hello"[0] }; |
| |
| static_assert(strcmp_ce(&agg1.c, "hello") == 0, ""); |
| static_assert(agg1.n == 0, ""); |
| static_assert(agg1.d == 0.0, ""); |
| static_assert(agg1.arr[-1] == 0, ""); // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} |
| static_assert(agg1.arr[0] == 0, ""); |
| static_assert(agg1.arr[4] == 0, ""); |
| static_assert(agg1.arr[5] == 0, ""); // expected-error {{constant expression}} expected-note {{read of dereferenced one-past-the-end}} |
| static_assert(agg1.p == nullptr, ""); |
| |
| static constexpr const unsigned char uc[] = { "foo" }; |
| static_assert(uc[0] == 'f', ""); |
| static_assert(uc[3] == 0, ""); |
| |
| namespace SimpleDerivedClass { |
| |
| struct B { |
| constexpr B(int n) : a(n) {} |
| int a; |
| }; |
| struct D : B { |
| constexpr D(int n) : B(n) {} |
| }; |
| constexpr D d(3); |
| static_assert(d.a == 3, ""); |
| |
| } |
| |
| struct Bottom { constexpr Bottom() {} }; |
| struct Base : Bottom { |
| constexpr Base(int a = 42, const char *b = "test") : a(a), b(b) {} |
| int a; |
| const char *b; |
| }; |
| struct Base2 : Bottom { |
| constexpr Base2(const int &r) : r(r) {} |
| int q = 123; |
| const int &r; |
| }; |
| struct Derived : Base, Base2 { |
| constexpr Derived() : Base(76), Base2(a) {} |
| int c = r + b[1]; |
| }; |
| |
| constexpr bool operator==(const Base &a, const Base &b) { |
| return a.a == b.a && strcmp_ce(a.b, b.b) == 0; |
| } |
| |
| constexpr Base base; |
| constexpr Base base2(76); |
| constexpr Derived derived; |
| static_assert(derived.a == 76, ""); |
| static_assert(derived.b[2] == 's', ""); |
| static_assert(derived.c == 76 + 'e', ""); |
| static_assert(derived.q == 123, ""); |
| static_assert(derived.r == 76, ""); |
| static_assert(&derived.r == &derived.a, ""); |
| |
| static_assert(!(derived == base), ""); |
| static_assert(derived == base2, ""); |
| |
| constexpr Bottom &bot1 = (Base&)derived; |
| constexpr Bottom &bot2 = (Base2&)derived; |
| static_assert(&bot1 != &bot2, ""); |
| |
| constexpr Bottom *pb1 = (Base*)&derived; |
| constexpr Bottom *pb2 = (Base2*)&derived; |
| static_assert(&pb1 != &pb2, ""); |
| static_assert(pb1 == &bot1, ""); |
| static_assert(pb2 == &bot2, ""); |
| |
| constexpr Base2 &fail = (Base2&)bot1; // expected-error {{constant expression}} expected-note {{cannot cast object of dynamic type 'const Class::Derived' to type 'Class::Base2'}} |
| constexpr Base &fail2 = (Base&)*pb2; // expected-error {{constant expression}} expected-note {{cannot cast object of dynamic type 'const Class::Derived' to type 'Class::Base'}} |
| constexpr Base2 &ok2 = (Base2&)bot2; |
| static_assert(&ok2 == &derived, ""); |
| |
| constexpr Base2 *pfail = (Base2*)pb1; // expected-error {{constant expression}} expected-note {{cannot cast object of dynamic type 'const Class::Derived' to type 'Class::Base2'}} |
| constexpr Base *pfail2 = (Base*)&bot2; // expected-error {{constant expression}} expected-note {{cannot cast object of dynamic type 'const Class::Derived' to type 'Class::Base'}} |
| constexpr Base2 *pok2 = (Base2*)pb2; |
| static_assert(pok2 == &derived, ""); |
| static_assert(&ok2 == pok2, ""); |
| static_assert((Base2*)(Derived*)(Base*)pb1 == pok2, ""); |
| static_assert((Derived*)(Base*)pb1 == (Derived*)pok2, ""); |
| |
| // Core issue 903: we do not perform constant evaluation when checking for a |
| // null pointer in C++11. Just check for an integer literal with value 0. |
| constexpr Base *nullB = 42 - 6 * 7; // expected-error {{cannot initialize a variable of type 'Class::Base *const' with an rvalue of type 'int'}} |
| constexpr Base *nullB1 = 0; |
| static_assert((Bottom*)nullB == 0, ""); |
| static_assert((Derived*)nullB == 0, ""); |
| static_assert((void*)(Bottom*)nullB == (void*)(Derived*)nullB, ""); |
| Base *nullB2 = '\0'; // expected-error {{cannot initialize a variable of type 'Class::Base *' with an rvalue of type 'char'}} |
| Base *nullB3 = (0); |
| Base *nullB4 = false; // expected-error {{cannot initialize a variable of type 'Class::Base *' with an rvalue of type 'bool'}} |
| Base *nullB5 = ((0ULL)); |
| Base *nullB6 = 0.; // expected-error {{cannot initialize a variable of type 'Class::Base *' with an rvalue of type 'double'}} |
| enum Null { kNull }; |
| Base *nullB7 = kNull; // expected-error {{cannot initialize a variable of type 'Class::Base *' with an rvalue of type 'Class::Null'}} |
| static_assert(nullB1 == (1 - 1), ""); // expected-error {{comparison between pointer and integer}} |
| |
| |
| |
| namespace ConversionOperators { |
| |
| struct T { |
| constexpr T(int n) : k(5*n - 3) {} |
| constexpr operator int() const { return k; } |
| int k; |
| }; |
| |
| struct S { |
| constexpr S(int n) : k(2*n + 1) {} |
| constexpr operator int() const { return k; } |
| constexpr operator T() const { return T(k); } |
| int k; |
| }; |
| |
| constexpr bool check(T a, T b) { return a == b.k; } |
| |
| static_assert(S(5) == 11, ""); |
| static_assert(check(S(5), 11), ""); |
| |
| namespace PR14171 { |
| |
| struct X { |
| constexpr (operator int)() const { return 0; } |
| }; |
| static_assert(X() == 0, ""); |
| |
| } |
| |
| } |
| |
| struct This { |
| constexpr int f() const { return 0; } |
| static constexpr int g() { return 0; } |
| void h() { |
| constexpr int x = f(); // expected-error {{must be initialized by a constant}} |
| // expected-note@-1 {{implicit use of 'this' pointer is only allowed within the evaluation of a call to a 'constexpr' member function}} |
| constexpr int y = this->f(); // expected-error {{must be initialized by a constant}} |
| // expected-note-re@-1 {{{{^}}use of 'this' pointer}} |
| constexpr int z = g(); |
| static_assert(z == 0, ""); |
| } |
| }; |
| |
| } |
| |
| namespace Temporaries { |
| |
| struct S { |
| constexpr S() {} |
| constexpr int f() const; |
| constexpr int g() const; |
| }; |
| struct T : S { |
| constexpr T(int n) : S(), n(n) {} |
| int n; |
| }; |
| constexpr int S::f() const { |
| return static_cast<const T*>(this)->n; // expected-note {{cannot cast}} |
| } |
| constexpr int S::g() const { |
| // FIXME: Better diagnostic for this. |
| return this->*(int(S::*))&T::n; // expected-note {{subexpression}} |
| } |
| // The T temporary is implicitly cast to an S subobject, but we can recover the |
| // T full-object via a base-to-derived cast, or a derived-to-base-casted member |
| // pointer. |
| static_assert(S().f(), ""); // expected-error {{constant expression}} expected-note {{in call to '&Temporaries::S()->f()'}} |
| static_assert(S().g(), ""); // expected-error {{constant expression}} expected-note {{in call to '&Temporaries::S()->g()'}} |
| static_assert(T(3).f() == 3, ""); |
| static_assert(T(4).g() == 4, ""); |
| |
| constexpr int f(const S &s) { |
| return static_cast<const T&>(s).n; |
| } |
| constexpr int n = f(T(5)); |
| static_assert(f(T(5)) == 5, ""); |
| |
| constexpr bool b(int n) { return &n; } |
| static_assert(b(0), ""); |
| |
| struct NonLiteral { |
| NonLiteral(); |
| int f(); |
| }; |
| constexpr int k = NonLiteral().f(); // expected-error {{constant expression}} expected-note {{non-literal type 'Temporaries::NonLiteral'}} |
| |
| } |
| |
| namespace Union { |
| |
| union U { |
| int a; |
| int b; |
| }; |
| |
| constexpr U u[4] = { { .a = 0 }, { .b = 1 }, { .a = 2 }, { .b = 3 } }; // expected-warning 4{{C99 feature}} |
| static_assert(u[0].a == 0, ""); |
| static_assert(u[0].b, ""); // expected-error {{constant expression}} expected-note {{read of member 'b' of union with active member 'a'}} |
| static_assert(u[1].b == 1, ""); |
| static_assert((&u[1].b)[1] == 2, ""); // expected-error {{constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}} |
| static_assert(*(&(u[1].b) + 1 + 1) == 3, ""); // expected-error {{constant expression}} expected-note {{cannot refer to element 2 of non-array object}} |
| static_assert((&(u[1]) + 1 + 1)->b == 3, ""); |
| |
| constexpr U v = {}; |
| static_assert(v.a == 0, ""); |
| |
| union Empty {}; |
| constexpr Empty e = {}; |
| |
| // Make sure we handle trivial copy constructors for unions. |
| constexpr U x = {42}; |
| constexpr U y = x; |
| static_assert(y.a == 42, ""); |
| static_assert(y.b == 42, ""); // expected-error {{constant expression}} expected-note {{'b' of union with active member 'a'}} |
| |
| } |
| |
| namespace MemberPointer { |
| struct A { |
| constexpr A(int n) : n(n) {} |
| int n; |
| constexpr int f() const { return n + 3; } |
| }; |
| constexpr A a(7); |
| static_assert(A(5).*&A::n == 5, ""); |
| static_assert((&a)->*&A::n == 7, ""); |
| static_assert((A(8).*&A::f)() == 11, ""); |
| static_assert(((&a)->*&A::f)() == 10, ""); |
| |
| struct B : A { |
| constexpr B(int n, int m) : A(n), m(m) {} |
| int m; |
| constexpr int g() const { return n + m + 1; } |
| }; |
| constexpr B b(9, 13); |
| static_assert(B(4, 11).*&A::n == 4, ""); |
| static_assert(B(4, 11).*&B::m == 11, ""); |
| static_assert(B(4, 11).*(int(A::*))&B::m == 11, ""); |
| static_assert((&b)->*&A::n == 9, ""); |
| static_assert((&b)->*&B::m == 13, ""); |
| static_assert((&b)->*(int(A::*))&B::m == 13, ""); |
| static_assert((B(4, 11).*&A::f)() == 7, ""); |
| static_assert((B(4, 11).*&B::g)() == 16, ""); |
| static_assert((B(4, 11).*(int(A::*)()const)&B::g)() == 16, ""); |
| static_assert(((&b)->*&A::f)() == 12, ""); |
| static_assert(((&b)->*&B::g)() == 23, ""); |
| static_assert(((&b)->*(int(A::*)()const)&B::g)() == 23, ""); |
| |
| struct S { |
| constexpr S(int m, int n, int (S::*pf)() const, int S::*pn) : |
| m(m), n(n), pf(pf), pn(pn) {} |
| constexpr S() : m(), n(), pf(&S::f), pn(&S::n) {} |
| |
| constexpr int f() const { return this->*pn; } |
| virtual int g() const; |
| |
| int m, n; |
| int (S::*pf)() const; |
| int S::*pn; |
| }; |
| |
| constexpr int S::*pm = &S::m; |
| constexpr int S::*pn = &S::n; |
| constexpr int (S::*pf)() const = &S::f; |
| constexpr int (S::*pg)() const = &S::g; |
| |
| constexpr S s(2, 5, &S::f, &S::m); |
| |
| static_assert((s.*&S::f)() == 2, ""); |
| static_assert((s.*s.pf)() == 2, ""); |
| |
| static_assert(pf == &S::f, ""); |
| static_assert(pf == s.*&S::pf, ""); |
| static_assert(pm == &S::m, ""); |
| static_assert(pm != pn, ""); |
| static_assert(s.pn != pn, ""); |
| static_assert(s.pn == pm, ""); |
| static_assert(pg != nullptr, ""); |
| static_assert(pf != nullptr, ""); |
| static_assert((int S::*)nullptr == nullptr, ""); |
| static_assert(pg == pg, ""); // expected-error {{constant expression}} expected-note {{comparison of pointer to virtual member function 'g' has unspecified value}} |
| static_assert(pf != pg, ""); // expected-error {{constant expression}} expected-note {{comparison of pointer to virtual member function 'g' has unspecified value}} |
| |
| template<int n> struct T : T<n-1> {}; |
| template<> struct T<0> { int n; }; |
| template<> struct T<30> : T<29> { int m; }; |
| |
| T<17> t17; |
| T<30> t30; |
| |
| constexpr int (T<10>::*deepn) = &T<0>::n; |
| static_assert(&(t17.*deepn) == &t17.n, ""); |
| static_assert(deepn == &T<2>::n, ""); |
| |
| constexpr int (T<15>::*deepm) = (int(T<10>::*))&T<30>::m; |
| constexpr int *pbad = &(t17.*deepm); // expected-error {{constant expression}} |
| static_assert(&(t30.*deepm) == &t30.m, ""); |
| static_assert(deepm == &T<50>::m, ""); |
| static_assert(deepm != deepn, ""); |
| |
| constexpr T<5> *p17_5 = &t17; |
| constexpr T<13> *p17_13 = (T<13>*)p17_5; |
| constexpr T<23> *p17_23 = (T<23>*)p17_13; // expected-error {{constant expression}} expected-note {{cannot cast object of dynamic type 'T<17>' to type 'T<23>'}} |
| static_assert(&(p17_5->*(int(T<3>::*))deepn) == &t17.n, ""); |
| static_assert(&(p17_13->*deepn) == &t17.n, ""); |
| constexpr int *pbad2 = &(p17_13->*(int(T<9>::*))deepm); // expected-error {{constant expression}} |
| |
| constexpr T<5> *p30_5 = &t30; |
| constexpr T<23> *p30_23 = (T<23>*)p30_5; |
| constexpr T<13> *p30_13 = p30_23; |
| static_assert(&(p30_5->*(int(T<3>::*))deepn) == &t30.n, ""); |
| static_assert(&(p30_13->*deepn) == &t30.n, ""); |
| static_assert(&(p30_23->*deepn) == &t30.n, ""); |
| static_assert(&(p30_5->*(int(T<2>::*))deepm) == &t30.m, ""); |
| static_assert(&(((T<17>*)p30_13)->*deepm) == &t30.m, ""); |
| static_assert(&(p30_23->*deepm) == &t30.m, ""); |
| |
| struct Base { int n; }; |
| template<int N> struct Mid : Base {}; |
| struct Derived : Mid<0>, Mid<1> {}; |
| static_assert(&Mid<0>::n == &Mid<1>::n, ""); |
| static_assert((int Derived::*)(int Mid<0>::*)&Mid<0>::n != |
| (int Derived::*)(int Mid<1>::*)&Mid<1>::n, ""); |
| static_assert(&Mid<0>::n == (int Mid<0>::*)&Base::n, ""); |
| } |
| |
| namespace ArrayBaseDerived { |
| |
| struct Base { |
| constexpr Base() {} |
| int n = 0; |
| }; |
| struct Derived : Base { |
| constexpr Derived() {} |
| constexpr const int *f() const { return &n; } |
| }; |
| |
| constexpr Derived a[10]; |
| constexpr Derived *pd3 = const_cast<Derived*>(&a[3]); |
| constexpr Base *pb3 = const_cast<Derived*>(&a[3]); |
| static_assert(pb3 == pd3, ""); |
| |
| // pb3 does not point to an array element. |
| constexpr Base *pb4 = pb3 + 1; // ok, one-past-the-end pointer. |
| constexpr int pb4n = pb4->n; // expected-error {{constant expression}} expected-note {{cannot access field of pointer past the end}} |
| constexpr Base *err_pb5 = pb3 + 2; // expected-error {{constant expression}} expected-note {{cannot refer to element 2}} expected-note {{here}} |
| constexpr int err_pb5n = err_pb5->n; // expected-error {{constant expression}} expected-note {{initializer of 'err_pb5' is not a constant expression}} |
| constexpr Base *err_pb2 = pb3 - 1; // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} expected-note {{here}} |
| constexpr int err_pb2n = err_pb2->n; // expected-error {{constant expression}} expected-note {{initializer of 'err_pb2'}} |
| constexpr Base *pb3a = pb4 - 1; |
| |
| // pb4 does not point to a Derived. |
| constexpr Derived *err_pd4 = (Derived*)pb4; // expected-error {{constant expression}} expected-note {{cannot access derived class of pointer past the end}} |
| constexpr Derived *pd3a = (Derived*)pb3a; |
| constexpr int pd3n = pd3a->n; |
| |
| // pd3a still points to the Derived array. |
| constexpr Derived *pd6 = pd3a + 3; |
| static_assert(pd6 == &a[6], ""); |
| constexpr Derived *pd9 = pd6 + 3; |
| constexpr Derived *pd10 = pd6 + 4; |
| constexpr int pd9n = pd9->n; // ok |
| constexpr int err_pd10n = pd10->n; // expected-error {{constant expression}} expected-note {{cannot access base class of pointer past the end}} |
| constexpr int pd0n = pd10[-10].n; |
| constexpr int err_pdminus1n = pd10[-11].n; // expected-error {{constant expression}} expected-note {{cannot refer to element -1 of}} |
| |
| constexpr Base *pb9 = pd9; |
| constexpr const int *(Base::*pfb)() const = |
| static_cast<const int *(Base::*)() const>(&Derived::f); |
| static_assert((pb9->*pfb)() == &a[9].n, ""); |
| } |
| |
| namespace Complex { |
| |
| class complex { |
| int re, im; |
| public: |
| constexpr complex(int re = 0, int im = 0) : re(re), im(im) {} |
| constexpr complex(const complex &o) : re(o.re), im(o.im) {} |
| constexpr complex operator-() const { return complex(-re, -im); } |
| friend constexpr complex operator+(const complex &l, const complex &r) { |
| return complex(l.re + r.re, l.im + r.im); |
| } |
| friend constexpr complex operator-(const complex &l, const complex &r) { |
| return l + -r; |
| } |
| friend constexpr complex operator*(const complex &l, const complex &r) { |
| return complex(l.re * r.re - l.im * r.im, l.re * r.im + l.im * r.re); |
| } |
| friend constexpr bool operator==(const complex &l, const complex &r) { |
| return l.re == r.re && l.im == r.im; |
| } |
| constexpr bool operator!=(const complex &r) const { |
| return re != r.re || im != r.im; |
| } |
| constexpr int real() const { return re; } |
| constexpr int imag() const { return im; } |
| }; |
| |
| constexpr complex i = complex(0, 1); |
| constexpr complex k = (3 + 4*i) * (6 - 4*i); |
| static_assert(complex(1,0).real() == 1, ""); |
| static_assert(complex(1,0).imag() == 0, ""); |
| static_assert(((complex)1).imag() == 0, ""); |
| static_assert(k.real() == 34, ""); |
| static_assert(k.imag() == 12, ""); |
| static_assert(k - 34 == 12*i, ""); |
| static_assert((complex)1 == complex(1), ""); |
| static_assert((complex)1 != complex(0, 1), ""); |
| static_assert(complex(1) == complex(1), ""); |
| static_assert(complex(1) != complex(0, 1), ""); |
| constexpr complex makeComplex(int re, int im) { return complex(re, im); } |
| static_assert(makeComplex(1,0) == complex(1), ""); |
| static_assert(makeComplex(1,0) != complex(0, 1), ""); |
| |
| class complex_wrap : public complex { |
| public: |
| constexpr complex_wrap(int re, int im = 0) : complex(re, im) {} |
| constexpr complex_wrap(const complex_wrap &o) : complex(o) {} |
| }; |
| |
| static_assert((complex_wrap)1 == complex(1), ""); |
| static_assert((complex)1 != complex_wrap(0, 1), ""); |
| static_assert(complex(1) == complex_wrap(1), ""); |
| static_assert(complex_wrap(1) != complex(0, 1), ""); |
| constexpr complex_wrap makeComplexWrap(int re, int im) { |
| return complex_wrap(re, im); |
| } |
| static_assert(makeComplexWrap(1,0) == complex(1), ""); |
| static_assert(makeComplexWrap(1,0) != complex(0, 1), ""); |
| |
| } |
| |
| namespace PR11595 { |
| struct A { constexpr bool operator==(int x) const { return true; } }; |
| struct B { B(); A& x; }; |
| static_assert(B().x == 3, ""); // expected-error {{constant expression}} expected-note {{non-literal type 'PR11595::B' cannot be used in a constant expression}} |
| |
| constexpr bool f(int k) { // expected-error {{constexpr function never produces a constant expression}} |
| return B().x == k; // expected-note {{non-literal type 'PR11595::B' cannot be used in a constant expression}} |
| } |
| } |
| |
| namespace ExprWithCleanups { |
| struct A { A(); ~A(); int get(); }; |
| constexpr int get(bool FromA) { return FromA ? A().get() : 1; } |
| constexpr int n = get(false); |
| } |
| |
| namespace Volatile { |
| |
| volatile constexpr int n1 = 0; // expected-note {{here}} |
| volatile const int n2 = 0; // expected-note {{here}} |
| int n3 = 37; // expected-note {{declared here}} |
| |
| constexpr int m1 = n1; // expected-error {{constant expression}} expected-note {{read of volatile-qualified type 'const volatile int'}} |
| constexpr int m2 = n2; // expected-error {{constant expression}} expected-note {{read of volatile-qualified type 'const volatile int'}} |
| constexpr int m1b = const_cast<const int&>(n1); // expected-error {{constant expression}} expected-note {{read of volatile object 'n1'}} |
| constexpr int m2b = const_cast<const int&>(n2); // expected-error {{constant expression}} expected-note {{read of volatile object 'n2'}} |
| |
| struct T { int n; }; |
| const T t = { 42 }; |
| |
| constexpr int f(volatile int &&r) { |
| return r; // expected-note {{read of volatile-qualified type 'volatile int'}} |
| } |
| constexpr int g(volatile int &&r) { |
| return const_cast<int&>(r); // expected-note {{read of volatile temporary is not allowed in a constant expression}} |
| } |
| struct S { |
| int j : f(0); // expected-error {{constant expression}} expected-note {{in call to 'f(0)'}} |
| int k : g(0); // expected-error {{constant expression}} expected-note {{temporary created here}} expected-note {{in call to 'g(0)'}} |
| int l : n3; // expected-error {{constant expression}} expected-note {{read of non-const variable}} |
| int m : t.n; // expected-warning{{width of bit-field 'm' (42 bits)}} expected-warning{{expression is not an integral constant expression}} expected-note{{read of non-constexpr variable 't' is not allowed}} |
| }; |
| |
| } |
| |
| namespace ExternConstexpr { |
| extern constexpr int n = 0; |
| extern constexpr int m; // expected-error {{constexpr variable declaration must be a definition}} |
| void f() { |
| extern constexpr int i; // expected-error {{constexpr variable declaration must be a definition}} |
| constexpr int j = 0; |
| constexpr int k; // expected-error {{default initialization of an object of const type}} |
| } |
| |
| extern const int q; |
| constexpr int g() { return q; } |
| constexpr int q = g(); |
| static_assert(q == 0, "zero-initialization should precede static initialization"); |
| |
| extern int r; // expected-note {{here}} |
| constexpr int h() { return r; } // expected-error {{never produces a constant}} expected-note {{read of non-const}} |
| |
| struct S { int n; }; |
| extern const S s; |
| constexpr int x() { return s.n; } |
| constexpr S s = {x()}; |
| static_assert(s.n == 0, "zero-initialization should precede static initialization"); |
| } |
| |
| namespace ComplexConstexpr { |
| constexpr _Complex float test1 = {}; |
| constexpr _Complex float test2 = {1}; |
| constexpr _Complex double test3 = {1,2}; |
| constexpr _Complex int test4 = {4}; |
| constexpr _Complex int test5 = 4; |
| constexpr _Complex int test6 = {5,6}; |
| typedef _Complex float fcomplex; |
| constexpr fcomplex test7 = fcomplex(); |
| |
| constexpr const double &t2r = __real test3; |
| constexpr const double &t2i = __imag test3; |
| static_assert(&t2r + 1 == &t2i, ""); |
| static_assert(t2r == 1.0, ""); |
| static_assert(t2i == 2.0, ""); |
| constexpr const double *t2p = &t2r; |
| static_assert(t2p[-1] == 0.0, ""); // expected-error {{constant expr}} expected-note {{cannot refer to element -1 of array of 2 elements}} |
| static_assert(t2p[0] == 1.0, ""); |
| static_assert(t2p[1] == 2.0, ""); |
| static_assert(t2p[2] == 0.0, ""); // expected-error {{constant expr}} expected-note {{one-past-the-end pointer}} |
| static_assert(t2p[3] == 0.0, ""); // expected-error {{constant expr}} expected-note {{cannot refer to element 3 of array of 2 elements}} |
| constexpr _Complex float *p = 0; |
| constexpr float pr = __real *p; // expected-error {{constant expr}} expected-note {{cannot access real component of null}} |
| constexpr float pi = __imag *p; // expected-error {{constant expr}} expected-note {{cannot access imaginary component of null}} |
| constexpr const _Complex double *q = &test3 + 1; |
| constexpr double qr = __real *q; // expected-error {{constant expr}} expected-note {{cannot access real component of pointer past the end}} |
| constexpr double qi = __imag *q; // expected-error {{constant expr}} expected-note {{cannot access imaginary component of pointer past the end}} |
| |
| static_assert(__real test6 == 5, ""); |
| static_assert(__imag test6 == 6, ""); |
| static_assert(&__imag test6 == &__real test6 + 1, ""); |
| } |
| |
| // _Atomic(T) is exactly like T for the purposes of constant expression |
| // evaluation.. |
| namespace Atomic { |
| constexpr _Atomic int n = 3; |
| |
| struct S { _Atomic(double) d; }; |
| constexpr S s = { 0.5 }; |
| constexpr double d1 = s.d; |
| constexpr double d2 = n; |
| constexpr _Atomic double d3 = n; |
| |
| constexpr _Atomic(int) n2 = d3; |
| static_assert(d1 == 0.5, ""); |
| static_assert(d3 == 3.0, ""); |
| |
| namespace PR16056 { |
| struct TestVar { |
| _Atomic(int) value; |
| constexpr TestVar(int value) : value(value) {} |
| }; |
| constexpr TestVar testVar{-1}; |
| static_assert(testVar.value == -1, ""); |
| } |
| |
| namespace PR32034 { |
| struct A {}; |
| struct B { _Atomic(A) a; }; |
| constexpr int n = (B(), B(), 0); |
| |
| struct C { constexpr C() {} void *self = this; }; |
| constexpr _Atomic(C) c = C(); |
| } |
| } |
| |
| namespace InstantiateCaseStmt { |
| template<int x> constexpr int f() { return x; } |
| template<int x> int g(int c) { switch(c) { case f<x>(): return 1; } return 0; } |
| int gg(int c) { return g<4>(c); } |
| } |
| |
| namespace ConvertedConstantExpr { |
| extern int &m; |
| extern int &n; |
| |
| constexpr int k = 4; |
| int &m = const_cast<int&>(k); |
| |
| // If we have nothing more interesting to say, ensure we don't produce a |
| // useless note and instead just point to the non-constant subexpression. |
| enum class E { |
| em = m, |
| en = n, // expected-error {{not a constant expression}} |
| eo = (m + |
| n // expected-error {{not a constant expression}} |
| ), |
| eq = reinterpret_cast<long>((int*)0) // expected-error {{not a constant expression}} expected-note {{reinterpret_cast}} |
| }; |
| } |
| |
| namespace IndirectField { |
| struct S { |
| struct { // expected-warning {{GNU extension}} |
| union { // expected-warning {{declared in an anonymous struct}} |
| struct { // expected-warning {{GNU extension}} expected-warning {{declared in an anonymous union}} |
| int a; |
| int b; |
| }; |
| int c; |
| }; |
| int d; |
| }; |
| union { |
| int e; |
| int f; |
| }; |
| constexpr S(int a, int b, int d, int e) : a(a), b(b), d(d), e(e) {} |
| constexpr S(int c, int d, int f) : c(c), d(d), f(f) {} |
| }; |
| |
| constexpr S s1(1, 2, 3, 4); |
| constexpr S s2(5, 6, 7); |
| |
| // FIXME: The diagnostics here do a very poor job of explaining which unnamed |
| // member is active and which is requested. |
| static_assert(s1.a == 1, ""); |
| static_assert(s1.b == 2, ""); |
| static_assert(s1.c == 0, ""); // expected-error {{constant expression}} expected-note {{union with active member}} |
| static_assert(s1.d == 3, ""); |
| static_assert(s1.e == 4, ""); |
| static_assert(s1.f == 0, ""); // expected-error {{constant expression}} expected-note {{union with active member}} |
| |
| static_assert(s2.a == 0, ""); // expected-error {{constant expression}} expected-note {{union with active member}} |
| static_assert(s2.b == 0, ""); // expected-error {{constant expression}} expected-note {{union with active member}} |
| static_assert(s2.c == 5, ""); |
| static_assert(s2.d == 6, ""); |
| static_assert(s2.e == 0, ""); // expected-error {{constant expression}} expected-note {{union with active member}} |
| static_assert(s2.f == 7, ""); |
| } |
| |
| // DR1405: don't allow reading mutable members in constant expressions. |
| namespace MutableMembers { |
| struct MM { |
| mutable int n; // expected-note 3{{declared here}} |
| } constexpr mm = { 4 }; |
| constexpr int mmn = mm.n; // expected-error {{constant expression}} expected-note {{read of mutable member 'n' is not allowed in a constant expression}} |
| int x = (mm.n = 1, 3); |
| constexpr int mmn2 = mm.n; // expected-error {{constant expression}} expected-note {{read of mutable member 'n' is not allowed in a constant expression}} |
| |
| // Here's one reason why allowing this would be a disaster... |
| template<int n> struct Id { int k = n; }; |
| int f() { |
| constexpr MM m = { 0 }; |
| ++m.n; |
| return Id<m.n>().k; // expected-error {{not a constant expression}} expected-note {{read of mutable member 'n' is not allowed in a constant expression}} |
| } |
| |
| struct A { int n; }; |
| struct B { mutable A a; }; // expected-note {{here}} |
| struct C { B b; }; |
| constexpr C c[3] = {}; |
| constexpr int k = c[1].b.a.n; // expected-error {{constant expression}} expected-note {{mutable}} |
| |
| struct D { int x; mutable int y; }; // expected-note {{here}} |
| constexpr D d1 = { 1, 2 }; |
| int l = ++d1.y; |
| constexpr D d2 = d1; // expected-error {{constant}} expected-note {{mutable}} expected-note {{in call}} |
| |
| struct E { |
| union { |
| int a; |
| mutable int b; // expected-note {{here}} |
| }; |
| }; |
| constexpr E e1 = {{1}}; |
| constexpr E e2 = e1; // expected-error {{constant}} expected-note {{mutable}} expected-note {{in call}} |
| |
| struct F { |
| union U { }; |
| mutable U u; |
| struct X { }; |
| mutable X x; |
| struct Y : X { X x; U u; }; |
| mutable Y y; |
| int n; |
| }; |
| // This is OK; we don't actually read any mutable state here. |
| constexpr F f1 = {}; |
| constexpr F f2 = f1; |
| |
| struct G { |
| struct X {}; |
| union U { X a; }; |
| mutable U u; // expected-note {{here}} |
| }; |
| constexpr G g1 = {}; |
| constexpr G g2 = g1; // expected-error {{constant}} expected-note {{mutable}} expected-note {{in call}} |
| constexpr G::U gu1 = {}; |
| constexpr G::U gu2 = gu1; |
| |
| union H { |
| mutable G::X gx; // expected-note {{here}} |
| }; |
| constexpr H h1 = {}; |
| constexpr H h2 = h1; // expected-error {{constant}} expected-note {{mutable}} expected-note {{in call}} |
| } |
| |
| namespace Fold { |
| |
| // This macro forces its argument to be constant-folded, even if it's not |
| // otherwise a constant expression. |
| #define fold(x) (__builtin_constant_p(x) ? (x) : (x)) |
| |
| constexpr int n = (long)(char*)123; // expected-error {{constant expression}} expected-note {{reinterpret_cast}} |
| constexpr int m = fold((long)(char*)123); // ok |
| static_assert(m == 123, ""); |
| |
| #undef fold |
| |
| } |
| |
| namespace DR1454 { |
| |
| constexpr const int &f(const int &n) { return n; } |
| constexpr int k1 = f(0); // ok |
| |
| struct Wrap { |
| const int &value; |
| }; |
| constexpr const Wrap &g(const Wrap &w) { return w; } |
| constexpr int k2 = g({0}).value; // ok |
| |
| // The temporary here has static storage duration, so we can bind a constexpr |
| // reference to it. |
| constexpr const int &i = 1; |
| constexpr const int j = i; |
| static_assert(j == 1, ""); |
| |
| // The temporary here is not const, so it can't be read outside the expression |
| // in which it was created (per the C++14 rules, which we use to avoid a C++11 |
| // defect). |
| constexpr int &&k = 1; // expected-note {{temporary created here}} |
| constexpr const int l = k; // expected-error {{constant expression}} expected-note {{read of temporary}} |
| |
| void f() { |
| // The temporary here has automatic storage duration, so we can't bind a |
| // constexpr reference to it. |
| constexpr const int &i = 1; // expected-error {{constant expression}} expected-note 2{{temporary}} |
| } |
| |
| } |
| |
| namespace RecursiveOpaqueExpr { |
| template<typename Iter> |
| constexpr auto LastNonzero(Iter p, Iter q) -> decltype(+*p) { |
| return p != q ? (LastNonzero(p+1, q) ?: *p) : 0; // expected-warning {{GNU}} |
| } |
| |
| constexpr int arr1[] = { 1, 0, 0, 3, 0, 2, 0, 4, 0, 0 }; |
| static_assert(LastNonzero(begin(arr1), end(arr1)) == 4, ""); |
| |
| constexpr int arr2[] = { 1, 0, 0, 3, 0, 2, 0, 4, 0, 5 }; |
| static_assert(LastNonzero(begin(arr2), end(arr2)) == 5, ""); |
| |
| constexpr int arr3[] = { |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, |
| 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; |
| static_assert(LastNonzero(begin(arr3), end(arr3)) == 2, ""); |
| } |
| |
| namespace VLASizeof { |
| |
| void f(int k) { |
| int arr[k]; // expected-warning {{C99}} |
| constexpr int n = 1 + |
| sizeof(arr) // expected-error {{constant expression}} |
| * 3; |
| } |
| } |
| |
| namespace CompoundLiteral { |
| // Matching GCC, file-scope array compound literals initialized by constants |
| // are lifetime-extended. |
| constexpr int *p = (int*)(int[1]){3}; // expected-warning {{C99}} |
| static_assert(*p == 3, ""); |
| static_assert((int[2]){1, 2}[1] == 2, ""); // expected-warning {{C99}} |
| |
| // Other kinds are not. |
| struct X { int a[2]; }; |
| constexpr int *n = (X){1, 2}.a; // expected-warning {{C99}} expected-warning {{temporary}} |
| // expected-error@-1 {{constant expression}} |
| // expected-note@-2 {{pointer to subobject of temporary}} |
| // expected-note@-3 {{temporary created here}} |
| |
| void f() { |
| static constexpr int *p = (int*)(int[1]){3}; // expected-warning {{C99}} expected-warning {{temporary}} |
| // expected-error@-1 {{constant expression}} |
| // expected-note@-2 {{pointer to subobject of temporary}} |
| // expected-note@-3 {{temporary created here}} |
| static_assert((int[2]){1, 2}[1] == 2, ""); // expected-warning {{C99}} |
| } |
| } |
| |
| namespace Vector { |
| typedef int __attribute__((vector_size(16))) VI4; |
| constexpr VI4 f(int n) { |
| return VI4 { n * 3, n + 4, n - 5, n / 6 }; |
| } |
| constexpr auto v1 = f(10); |
| |
| typedef double __attribute__((vector_size(32))) VD4; |
| constexpr VD4 g(int n) { |
| return (VD4) { n / 2.0, n + 1.5, n - 5.4, n * 0.9 }; // expected-warning {{C99}} |
| } |
| constexpr auto v2 = g(4); |
| } |
| |
| // PR12626, redux |
| namespace InvalidClasses { |
| void test0() { |
| struct X; // expected-note {{forward declaration}} |
| struct Y { bool b; X x; }; // expected-error {{field has incomplete type}} |
| Y y; |
| auto& b = y.b; |
| } |
| } |
| |
| namespace NamespaceAlias { |
| constexpr int f() { |
| namespace NS = NamespaceAlias; // expected-warning {{use of this statement in a constexpr function is a C++14 extension}} |
| return &NS::f != nullptr; |
| } |
| } |
| |
| // Constructors can be implicitly constexpr, even for a non-literal type. |
| namespace ImplicitConstexpr { |
| struct Q { Q() = default; Q(const Q&) = default; Q(Q&&) = default; ~Q(); }; // expected-note 3{{here}} |
| struct R { constexpr R() noexcept; constexpr R(const R&) noexcept; constexpr R(R&&) noexcept; ~R() noexcept; }; |
| struct S { R r; }; // expected-note 3{{here}} |
| struct T { T(const T&) noexcept; T(T &&) noexcept; ~T() noexcept; }; |
| struct U { T t; }; // expected-note 3{{here}} |
| static_assert(!__is_literal_type(Q), ""); |
| static_assert(!__is_literal_type(R), ""); |
| static_assert(!__is_literal_type(S), ""); |
| static_assert(!__is_literal_type(T), ""); |
| static_assert(!__is_literal_type(U), ""); |
| struct Test { |
| friend Q::Q() noexcept; // expected-error {{follows constexpr}} |
| friend Q::Q(Q&&) noexcept; // expected-error {{follows constexpr}} |
| friend Q::Q(const Q&) noexcept; // expected-error {{follows constexpr}} |
| friend S::S() noexcept; // expected-error {{follows constexpr}} |
| friend S::S(S&&) noexcept; // expected-error {{follows constexpr}} |
| friend S::S(const S&) noexcept; // expected-error {{follows constexpr}} |
| friend constexpr U::U() noexcept; // expected-error {{follows non-constexpr}} |
| friend constexpr U::U(U&&) noexcept; // expected-error {{follows non-constexpr}} |
| friend constexpr U::U(const U&) noexcept; // expected-error {{follows non-constexpr}} |
| }; |
| } |
| |
| // Indirectly test that an implicit lvalue to xvalue conversion performed for |
| // an NRVO move operation isn't implemented as CK_LValueToRValue. |
| namespace PR12826 { |
| struct Foo {}; |
| constexpr Foo id(Foo x) { return x; } |
| constexpr Foo res(id(Foo())); |
| } |
| |
| namespace PR13273 { |
| struct U { |
| int t; |
| U() = default; |
| }; |
| |
| struct S : U { |
| S() = default; |
| }; |
| |
| // S's default constructor isn't constexpr, because U's default constructor |
| // doesn't initialize 't', but it's trivial, so value-initialization doesn't |
| // actually call it. |
| static_assert(S{}.t == 0, ""); |
| } |
| |
| namespace PR12670 { |
| struct S { |
| constexpr S(int a0) : m(a0) {} |
| constexpr S() : m(6) {} |
| int m; |
| }; |
| constexpr S x[3] = { {4}, 5 }; |
| static_assert(x[0].m == 4, ""); |
| static_assert(x[1].m == 5, ""); |
| static_assert(x[2].m == 6, ""); |
| } |
| |
| // Indirectly test that an implicit lvalue-to-rvalue conversion is performed |
| // when a conditional operator has one argument of type void and where the other |
| // is a glvalue of class type. |
| namespace ConditionalLValToRVal { |
| struct A { |
| constexpr A(int a) : v(a) {} |
| int v; |
| }; |
| |
| constexpr A f(const A &a) { |
| return a.v == 0 ? throw a : a; |
| } |
| |
| constexpr A a(4); |
| static_assert(f(a).v == 4, ""); |
| } |
| |
| namespace TLS { |
| __thread int n; |
| int m; |
| |
| constexpr bool b = &n == &n; |
| |
| constexpr int *p = &n; // expected-error{{constexpr variable 'p' must be initialized by a constant expression}} |
| |
| constexpr int *f() { return &n; } |
| constexpr int *q = f(); // expected-error{{constexpr variable 'q' must be initialized by a constant expression}} |
| constexpr bool c = f() == f(); |
| |
| constexpr int *g() { return &m; } |
| constexpr int *r = g(); |
| } |
| |
| namespace Void { |
| constexpr void f() { return; } // expected-error{{constexpr function's return type 'void' is not a literal type}} |
| |
| void assert_failed(const char *msg, const char *file, int line); // expected-note {{declared here}} |
| #define ASSERT(expr) ((expr) ? static_cast<void>(0) : assert_failed(#expr, __FILE__, __LINE__)) |
| template<typename T, size_t S> |
| constexpr T get(T (&a)[S], size_t k) { |
| return ASSERT(k > 0 && k < S), a[k]; // expected-note{{non-constexpr function 'assert_failed'}} |
| } |
| #undef ASSERT |
| template int get(int (&a)[4], size_t); |
| constexpr int arr[] = { 4, 1, 2, 3, 4 }; |
| static_assert(get(arr, 1) == 1, ""); |
| static_assert(get(arr, 4) == 4, ""); |
| static_assert(get(arr, 0) == 4, ""); // expected-error{{not an integral constant expression}} \ |
| // expected-note{{in call to 'get(arr, 0)'}} |
| } |
| |
| namespace std { struct type_info; } |
| |
| namespace TypeId { |
| struct A { virtual ~A(); }; |
| A f(); |
| A &g(); |
| constexpr auto &x = typeid(f()); |
| constexpr auto &y = typeid(g()); // expected-error{{constant expression}} \ |
| // expected-note{{typeid applied to expression of polymorphic type 'TypeId::A' is not allowed in a constant expression}} \ |
| // expected-warning {{expression with side effects will be evaluated despite being used as an operand to 'typeid'}} |
| } |
| |
| namespace PR14203 { |
| struct duration { |
| constexpr duration() {} |
| constexpr operator int() const { return 0; } |
| }; |
| template<typename T> void f() { |
| // If we want to evaluate this at the point of the template definition, we |
| // need to trigger the implicit definition of the move constructor at that |
| // point. |
| // FIXME: C++ does not permit us to implicitly define it at the appropriate |
| // times, since it is only allowed to be implicitly defined when it is |
| // odr-used. |
| constexpr duration d = duration(); |
| } |
| // FIXME: It's unclear whether this is valid. On the one hand, we're not |
| // allowed to generate a move constructor. On the other hand, if we did, |
| // this would be a constant expression. For now, we generate a move |
| // constructor here. |
| int n = sizeof(short{duration(duration())}); |
| } |
| |
| namespace ArrayEltInit { |
| struct A { |
| constexpr A() : p(&p) {} |
| void *p; |
| }; |
| constexpr A a[10]; |
| static_assert(a[0].p == &a[0].p, ""); |
| static_assert(a[9].p == &a[9].p, ""); |
| static_assert(a[0].p != &a[9].p, ""); |
| static_assert(a[9].p != &a[0].p, ""); |
| |
| constexpr A b[10] = {}; |
| static_assert(b[0].p == &b[0].p, ""); |
| static_assert(b[9].p == &b[9].p, ""); |
| static_assert(b[0].p != &b[9].p, ""); |
| static_assert(b[9].p != &b[0].p, ""); |
| } |
| |
| namespace PR15884 { |
| struct S {}; |
| constexpr S f() { return {}; } |
| constexpr S *p = &f(); |
| // expected-error@-1 {{taking the address of a temporary}} |
| // expected-error@-2 {{constexpr variable 'p' must be initialized by a constant expression}} |
| // expected-note@-3 {{pointer to temporary is not a constant expression}} |
| // expected-note@-4 {{temporary created here}} |
| } |
| |
| namespace AfterError { |
| // FIXME: Suppress the 'no return statements' diagnostic if the body is invalid. |
| constexpr int error() { // expected-error {{no return statement}} |
| return foobar; // expected-error {{undeclared identifier}} |
| } |
| constexpr int k = error(); |
| } |
| |
| namespace std { |
| typedef decltype(sizeof(int)) size_t; |
| |
| template <class _E> |
| class initializer_list |
| { |
| const _E* __begin_; |
| size_t __size_; |
| |
| constexpr initializer_list(const _E* __b, size_t __s) |
| : __begin_(__b), |
| __size_(__s) |
| {} |
| |
| public: |
| typedef _E value_type; |
| typedef const _E& reference; |
| typedef const _E& const_reference; |
| typedef size_t size_type; |
| |
| typedef const _E* iterator; |
| typedef const _E* const_iterator; |
| |
| constexpr initializer_list() : __begin_(nullptr), __size_(0) {} |
| |
| constexpr size_t size() const {return __size_;} |
| constexpr const _E* begin() const {return __begin_;} |
| constexpr const _E* end() const {return __begin_ + __size_;} |
| }; |
| } |
| |
| namespace InitializerList { |
| constexpr int sum(const int *b, const int *e) { |
| return b != e ? *b + sum(b+1, e) : 0; |
| } |
| constexpr int sum(std::initializer_list<int> ints) { |
| return sum(ints.begin(), ints.end()); |
| } |
| static_assert(sum({1, 2, 3, 4, 5}) == 15, ""); |
| |
| static_assert(*std::initializer_list<int>{1, 2, 3}.begin() == 1, ""); |
| static_assert(std::initializer_list<int>{1, 2, 3}.begin()[2] == 3, ""); |
| } |
| |
| namespace StmtExpr { |
| struct A { int k; }; |
| void f() { |
| static_assert(({ const int x = 5; x * 3; }) == 15, ""); // expected-warning {{extension}} |
| constexpr auto a = ({ A(); }); // expected-warning {{extension}} |
| } |
| constexpr int g(int k) { |
| return ({ // expected-warning {{extension}} |
| const int x = k; |
| x * x; |
| }); |
| } |
| static_assert(g(123) == 15129, ""); |
| constexpr int h() { // expected-error {{never produces a constant}} |
| return ({ // expected-warning {{extension}} |
| return 0; // expected-note {{not supported}} |
| 1; |
| }); |
| } |
| } |
| |
| namespace VirtualFromBase { |
| struct S1 { |
| virtual int f() const; |
| }; |
| struct S2 { |
| virtual int f(); |
| }; |
| template <typename T> struct X : T { |
| constexpr X() {} |
| double d = 0.0; |
| constexpr int f() { return sizeof(T); } // expected-warning {{will not be implicitly 'const' in C++14}} |
| }; |
| |
| // Virtual f(), not OK. |
| constexpr X<X<S1>> xxs1; |
| constexpr X<S1> *p = const_cast<X<X<S1>>*>(&xxs1); |
| static_assert(p->f() == sizeof(X<S1>), ""); // expected-error {{constant expression}} expected-note {{virtual function call}} |
| |
| // Non-virtual f(), OK. |
| constexpr X<X<S2>> xxs2; |
| constexpr X<S2> *q = const_cast<X<X<S2>>*>(&xxs2); |
| static_assert(q->f() == sizeof(S2), ""); |
| } |
| |
| namespace ConstexprConstructorRecovery { |
| class X { |
| public: |
| enum E : short { |
| headers = 0x1, |
| middlefile = 0x2, |
| choices = 0x4 |
| }; |
| constexpr X() noexcept {}; |
| protected: |
| E val{0}; // expected-error {{cannot initialize a member subobject of type 'ConstexprConstructorRecovery::X::E' with an rvalue of type 'int'}} |
| }; |
| constexpr X x{}; |
| } |
| |
| namespace Lifetime { |
| void f() { |
| constexpr int &n = n; // expected-error {{constant expression}} expected-note {{use of reference outside its lifetime}} expected-warning {{not yet bound to a value}} |
| constexpr int m = m; // expected-error {{constant expression}} expected-note {{read of object outside its lifetime}} |
| } |
| |
| constexpr int &get(int &&n) { return n; } |
| constexpr int &&get_rv(int &&n) { return static_cast<int&&>(n); } |
| struct S { |
| int &&r; |
| int &s; |
| int t; |
| constexpr S() : r(get_rv(0)), s(get(0)), t(r) {} // expected-note {{read of object outside its lifetime}} |
| constexpr S(int) : r(get_rv(0)), s(get(0)), t(s) {} // expected-note {{read of object outside its lifetime}} |
| }; |
| constexpr int k1 = S().t; // expected-error {{constant expression}} expected-note {{in call}} |
| constexpr int k2 = S(0).t; // expected-error {{constant expression}} expected-note {{in call}} |
| } |
| |
| namespace Bitfields { |
| struct A { |
| bool b : 1; |
| unsigned u : 5; |
| int n : 5; |
| bool b2 : 3; |
| unsigned u2 : 74; // expected-warning {{exceeds the width of its type}} |
| int n2 : 81; // expected-warning {{exceeds the width of its type}} |
| }; |
| |
| constexpr A a = { false, 33, 31, false, 0xffffffff, 0x7fffffff }; // expected-warning 2{{truncation}} |
| static_assert(a.b == 0 && a.u == 1 && a.n == -1 && a.b2 == 0 && |
| a.u2 + 1 == 0 && a.n2 == 0x7fffffff, |
| "bad truncation of bitfield values"); |
| |
| struct B { |
| int n : 3; |
| constexpr B(int k) : n(k) {} |
| }; |
| static_assert(B(3).n == 3, ""); |
| static_assert(B(4).n == -4, ""); |
| static_assert(B(7).n == -1, ""); |
| static_assert(B(8).n == 0, ""); |
| static_assert(B(-1).n == -1, ""); |
| static_assert(B(-8889).n == -1, ""); |
| |
| namespace PR16755 { |
| struct X { |
| int x : 1; |
| constexpr static int f(int x) { |
| return X{x}.x; |
| } |
| }; |
| static_assert(X::f(3) == -1, "3 should truncate to -1"); |
| } |
| |
| struct HasUnnamedBitfield { |
| unsigned a; |
| unsigned : 20; |
| unsigned b; |
| |
| constexpr HasUnnamedBitfield() : a(), b() {} |
| constexpr HasUnnamedBitfield(unsigned a, unsigned b) : a(a), b(b) {} |
| }; |
| |
| void testUnnamedBitfield() { |
| const HasUnnamedBitfield zero{}; |
| int a = 1 / zero.b; // expected-warning {{division by zero is undefined}} |
| const HasUnnamedBitfield oneZero{1, 0}; |
| int b = 1 / oneZero.b; // expected-warning {{division by zero is undefined}} |
| } |
| } |
| |
| namespace ZeroSizeTypes { |
| constexpr int (*p1)[0] = 0, (*p2)[0] = 0; |
| constexpr int k = p2 - p1; |
| // expected-error@-1 {{constexpr variable 'k' must be initialized by a constant expression}} |
| // expected-note@-2 {{subtraction of pointers to type 'int [0]' of zero size}} |
| |
| int arr[5][0]; |
| constexpr int f() { // expected-error {{never produces a constant expression}} |
| return &arr[3] - &arr[0]; // expected-note {{subtraction of pointers to type 'int [0]' of zero size}} |
| } |
| } |
| |
| namespace BadDefaultInit { |
| template<int N> struct X { static const int n = N; }; |
| |
| struct A { |
| int k = // expected-note {{default member initializer declared here}} |
| X<A().k>::n; // expected-error {{default member initializer for 'k' needed within definition of enclosing class}} |
| }; |
| |
| // FIXME: The "constexpr constructor must initialize all members" diagnostic |
| // here is bogus (we discard the k(k) initializer because the parameter 'k' |
| // has been marked invalid). |
| struct B { // expected-note 2{{candidate}} |
| constexpr B( // expected-error {{must initialize all members}} expected-note {{candidate}} |
| int k = X<B().k>::n) : // expected-error {{no matching constructor}} |
| k(k) {} |
| int k; // expected-note {{not initialized}} |
| }; |
| } |
| |
| namespace NeverConstantTwoWays { |
| // If we see something non-constant but foldable followed by something |
| // non-constant and not foldable, we want the first diagnostic, not the |
| // second. |
| constexpr int f(int n) { // expected-error {{never produces a constant expression}} |
| return (int *)(long)&n == &n ? // expected-note {{reinterpret_cast}} |
| 1 / 0 : // expected-warning {{division by zero}} |
| 0; |
| } |
| |
| constexpr int n = // expected-error {{must be initialized by a constant expression}} |
| (int *)(long)&n == &n ? // expected-note {{reinterpret_cast}} |
| 1 / 0 : |
| 0; |
| } |
| |
| namespace PR17800 { |
| struct A { |
| constexpr int operator()() const { return 0; } |
| }; |
| template <typename ...T> constexpr int sink(T ...) { |
| return 0; |
| } |
| template <int ...N> constexpr int run() { |
| return sink(A()() + N ...); |
| } |
| constexpr int k = run<1, 2, 3>(); |
| } |
| |
| namespace BuiltinStrlen { |
| constexpr const char *a = "foo\0quux"; |
| constexpr char b[] = "foo\0quux"; |
| constexpr int f() { return 'u'; } |
| constexpr char c[] = { 'f', 'o', 'o', 0, 'q', f(), 'u', 'x', 0 }; |
| |
| static_assert(__builtin_strlen("foo") == 3, ""); |
| static_assert(__builtin_strlen("foo\0quux") == 3, ""); |
| static_assert(__builtin_strlen("foo\0quux" + 4) == 4, ""); |
| |
| constexpr bool check(const char *p) { |
| return __builtin_strlen(p) == 3 && |
| __builtin_strlen(p + 1) == 2 && |
| __builtin_strlen(p + 2) == 1 && |
| __builtin_strlen(p + 3) == 0 && |
| __builtin_strlen(p + 4) == 4 && |
| __builtin_strlen(p + 5) == 3 && |
| __builtin_strlen(p + 6) == 2 && |
| __builtin_strlen(p + 7) == 1 && |
| __builtin_strlen(p + 8) == 0; |
| } |
| |
| static_assert(check(a), ""); |
| static_assert(check(b), ""); |
| static_assert(check(c), ""); |
| |
| constexpr int over1 = __builtin_strlen(a + 9); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| constexpr int over2 = __builtin_strlen(b + 9); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| constexpr int over3 = __builtin_strlen(c + 9); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| |
| constexpr int under1 = __builtin_strlen(a - 1); // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} |
| constexpr int under2 = __builtin_strlen(b - 1); // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} |
| constexpr int under3 = __builtin_strlen(c - 1); // expected-error {{constant expression}} expected-note {{cannot refer to element -1}} |
| |
| // FIXME: The diagnostic here could be better. |
| constexpr char d[] = { 'f', 'o', 'o' }; // no nul terminator. |
| constexpr int bad = __builtin_strlen(d); // expected-error {{constant expression}} expected-note {{one-past-the-end}} |
| } |
| |
| namespace PR19010 { |
| struct Empty {}; |
| struct Empty2 : Empty {}; |
| struct Test : Empty2 { |
| constexpr Test() {} |
| Empty2 array[2]; |
| }; |
| void test() { constexpr Test t; } |
| } |
| |
| void PR21327(int a, int b) { |
| static_assert(&a + 1 != &b, ""); // expected-error {{constant expression}} |
| } |
| |
| namespace EmptyClass { |
| struct E1 {} e1; |
| union E2 {} e2; // expected-note {{here}} |
| struct E3 : E1 {} e3; |
| |
| // The defaulted copy constructor for an empty class does not read any |
| // members. The defaulted copy constructor for an empty union reads the |
| // object representation. |
| constexpr E1 e1b(e1); |
| constexpr E2 e2b(e2); // expected-error {{constant expression}} expected-note{{read of non-const}} expected-note {{in call}} |
| constexpr E3 e3b(e3); |
| } |
| |
| namespace PR21786 { |
| extern void (*start[])(); |
| extern void (*end[])(); |
| static_assert(&start != &end, ""); // expected-error {{constant expression}} |
| static_assert(&start != nullptr, ""); |
| |
| struct Foo; |
| struct Bar { |
| static const Foo x; |
| static const Foo y; |
| }; |
| static_assert(&Bar::x != nullptr, ""); |
| static_assert(&Bar::x != &Bar::y, ""); |
| } |
| |
| namespace PR21859 { |
| constexpr int Fun() { return; } // expected-error {{non-void constexpr function 'Fun' should return a value}} |
| constexpr int Var = Fun(); |
| } |
| |
| struct InvalidRedef { |
| int f; // expected-note{{previous definition is here}} |
| constexpr int f(void); // expected-error{{redefinition of 'f'}} expected-warning{{will not be implicitly 'const'}} |
| }; |
| |
| namespace PR17938 { |
| template <typename T> constexpr T const &f(T const &x) { return x; } |
| |
| struct X {}; |
| struct Y : X {}; |
| struct Z : Y { constexpr Z() {} }; |
| |
| static constexpr auto z = f(Z()); |
| } |
| |
| namespace PR24597 { |
| struct A { |
| int x, *p; |
| constexpr A() : x(0), p(&x) {} |
| constexpr A(const A &a) : x(a.x), p(&x) {} |
| }; |
| constexpr A f() { return A(); } |
| constexpr A g() { return f(); } |
| constexpr int a = *f().p; |
| constexpr int b = *g().p; |
| } |
| |
| namespace IncompleteClass { |
| struct XX { |
| static constexpr int f(XX*) { return 1; } // expected-note {{here}} |
| friend constexpr int g(XX*) { return 2; } // expected-note {{here}} |
| |
| static constexpr int i = f(static_cast<XX*>(nullptr)); // expected-error {{constexpr variable 'i' must be initialized by a constant expression}} expected-note {{undefined function 'f' cannot be used in a constant expression}} |
| static constexpr int j = g(static_cast<XX*>(nullptr)); // expected-error {{constexpr variable 'j' must be initialized by a constant expression}} expected-note {{undefined function 'g' cannot be used in a constant expression}} |
| }; |
| } |
| |
| namespace InheritedCtor { |
| struct A { constexpr A(int) {} }; |
| |
| struct B : A { int n; using A::A; }; // expected-note {{here}} |
| constexpr B b(0); // expected-error {{constant expression}} expected-note {{derived class}} |
| |
| struct C : A { using A::A; struct { union { int n, m = 0; }; union { int a = 0; }; int k = 0; }; struct {}; union {}; }; // expected-warning 4{{extension}} |
| constexpr C c(0); |
| |
| struct D : A { |
| using A::A; // expected-note {{here}} |
| struct { // expected-warning {{extension}} |
| union { // expected-warning {{extension}} |
| int n; |
| }; |
| }; |
| }; |
| constexpr D d(0); // expected-error {{constant expression}} expected-note {{derived class}} |
| |
| struct E : virtual A { using A::A; }; // expected-note {{here}} |
| // We wrap a function around this to avoid implicit zero-initialization |
| // happening first; the zero-initialization step would produce the same |
| // error and defeat the point of this test. |
| void f() { |
| constexpr E e(0); // expected-error {{constant expression}} expected-note {{derived class}} |
| } |
| // FIXME: This produces a note with no source location. |
| //constexpr E e(0); |
| |
| struct W { constexpr W(int n) : w(n) {} int w; }; |
| struct X : W { using W::W; int x = 2; }; |
| struct Y : X { using X::X; int y = 3; }; |
| struct Z : Y { using Y::Y; int z = 4; }; |
| constexpr Z z(1); |
| static_assert(z.w == 1 && z.x == 2 && z.y == 3 && z.z == 4, ""); |
| } |
| |
| |
| namespace PR28366 { |
| namespace ns1 { |
| |
| void f(char c) { //expected-note2{{declared here}} |
| struct X { |
| static constexpr char f() { //expected-error{{never produces a constant expression}} |
| return c; //expected-error{{reference to local}} expected-note{{non-const variable}} |
| } |
| }; |
| int I = X::f(); |
| } |
| |
| void g() { |
| const int c = 'c'; |
| static const int d = 'd'; |
| struct X { |
| static constexpr int f() { |
| return c + d; |
| } |
| }; |
| static_assert(X::f() == 'c' + 'd',""); |
| } |
| |
| |
| } // end ns1 |
| |
| } //end ns PR28366 |
| |
| namespace PointerArithmeticOverflow { |
| int n; |
| int a[1]; |
| constexpr int *b = &n + 1 + (long)-1; |
| constexpr int *c = &n + 1 + (unsigned long)-1; // expected-error {{constant expression}} expected-note {{cannot refer to element 1844}} |
| constexpr int *d = &n + 1 - (unsigned long)1; |
| constexpr int *e = a + 1 + (long)-1; |
| constexpr int *f = a + 1 + (unsigned long)-1; // expected-error {{constant expression}} expected-note {{cannot refer to element 1844}} |
| constexpr int *g = a + 1 - (unsigned long)1; |
| |
| constexpr int *p = (&n + 1) + (unsigned __int128)-1; // expected-error {{constant expression}} expected-note {{cannot refer to element 3402}} |
| constexpr int *q = (&n + 1) - (unsigned __int128)-1; // expected-error {{constant expression}} expected-note {{cannot refer to element -3402}} |
| constexpr int *r = &(&n + 1)[(unsigned __int128)-1]; // expected-error {{constant expression}} expected-note {{cannot refer to element 3402}} |
| } |
