// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify=expected,both %s
// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify=expected,both %s
// RUN: %clang_cc1 -verify=ref,both %s
// RUN: %clang_cc1 -verify=ref,both -std=c++20 %s
constexpr int m = 3;
constexpr const int *foo[][5] = {
{nullptr, &m, nullptr, nullptr, nullptr},
{nullptr, nullptr, &m, nullptr, nullptr},
{nullptr, nullptr, nullptr, &m, nullptr},
};
static_assert(foo[0][0] == nullptr, "");
static_assert(foo[0][1] == &m, "");
static_assert(foo[0][2] == nullptr, "");
static_assert(foo[0][3] == nullptr, "");
static_assert(foo[0][4] == nullptr, "");
static_assert(foo[1][0] == nullptr, "");
static_assert(foo[1][1] == nullptr, "");
static_assert(foo[1][2] == &m, "");
static_assert(foo[1][3] == nullptr, "");
static_assert(foo[1][4] == nullptr, "");
static_assert(foo[2][0] == nullptr, "");
static_assert(foo[2][1] == nullptr, "");
static_assert(foo[2][2] == nullptr, "");
static_assert(foo[2][3] == &m, "");
static_assert(foo[2][4] == nullptr, "");
constexpr int afterEnd[] = {1,2,3};
static_assert(&afterEnd[3] == afterEnd + 3, "");
constexpr int ZeroSizeArray[] = {};
constexpr int SomeInt[] = {1};
constexpr int getSomeInt() { return *SomeInt; }
static_assert(getSomeInt() == 1, "");
/// A init list for a primitive value.
constexpr int f{5};
static_assert(f == 5, "");
constexpr int getElement(int i) {
int values[] = {1, 4, 9, 16, 25, 36};
return values[i];
}
static_assert(getElement(1) == 4, "");
static_assert(getElement(5) == 36, "");
constexpr int data[] = {5, 4, 3, 2, 1};
constexpr int getElement(const int *Arr, int index) {
return *(Arr + index);
}
constexpr int derefPtr(const int *d) {
return *d;
}
static_assert(derefPtr(data) == 5, "");
/// Make sure we can refer to the one-past-the-end element
/// and then return back to the end of the array.
static_assert((&data[5])[-1] == 1, "");
constexpr int storePtr() {
int b[] = {1,2,3,4};
int *c = b;
*c = 4;
return *c;
}
static_assert(storePtr() == 4, "");
static_assert(getElement(data, 1) == 4, "");
static_assert(getElement(data, 4) == 1, "");
constexpr int getElementFromEnd(const int *Arr, int size, int index) {
return *(Arr + size - index - 1);
}
static_assert(getElementFromEnd(data, 5, 0) == 1, "");
static_assert(getElementFromEnd(data, 5, 4) == 5, "");
constexpr int getFirstElem(const int *a) {
return a[0]; // both-note {{read of dereferenced null pointer}}
}
static_assert(getFirstElem(nullptr) == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
constexpr static int arr[2] = {1,2};
constexpr static int arr2[2] = {3,4};
constexpr int *p1 = nullptr;
constexpr int *p2 = p1 + 1; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot perform pointer arithmetic on null pointer}}
constexpr int *p3 = p1 + 0;
constexpr int *p4 = p1 - 0;
constexpr int *p5 = 0 + p1;
constexpr int *p6 = 0 - p1; // both-error {{invalid operands to binary expression}}
constexpr int const * ap1 = &arr[0];
constexpr int const * ap2 = ap1 + 3; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot refer to element 3 of array of 2}}
constexpr auto ap3 = arr - 1; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot refer to element -1}}
constexpr int k1 = &arr[1] - &arr[0];
static_assert(k1 == 1, "");
static_assert((&arr[0] - &arr[1]) == -1, "");
constexpr int k2 = &arr2[1] - &arr[0]; // both-error {{must be initialized by a constant expression}}
static_assert((arr + 0) == arr, "");
static_assert(&arr[0] == arr, "");
static_assert(*(&arr[0]) == 1, "");
static_assert(*(&arr[1]) == 2, "");
constexpr const int *OOB = (arr + 3) - 3; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot refer to element 3 of array of 2 elements}}
template<typename T>
constexpr T getElementOf(T* array, int i) {
return array[i];
}
static_assert(getElementOf(foo[0], 1) == &m, "");
template <typename T, int N>
constexpr T& getElementOfArray(T (&array)[N], int I) {
return array[I];
}
static_assert(getElementOfArray(foo[2], 3) == &m, "");
static_assert(data[0] == 4, ""); // both-error{{failed}} \
// both-note{{5 == 4}}
constexpr int dynamic[] = {
f, 3, 2 + 5, data[3], *getElementOf(foo[2], 3)
};
static_assert(dynamic[0] == f, "");
static_assert(dynamic[3] == 2, "");
constexpr int dependent[4] = {
0, 1, dependent[0], dependent[1]
};
static_assert(dependent[2] == dependent[0], "");
static_assert(dependent[3] == dependent[1], "");
union { char x[]; } r = {0};
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wc99-extensions"
#pragma clang diagnostic ignored "-Winitializer-overrides"
constexpr int DI[] = {
[0] = 10,
[1] = 20,
30,
40,
[1] = 50
};
static_assert(DI[0] == 10, "");
static_assert(DI[1] == 50, "");
static_assert(DI[2] == 30, "");
static_assert(DI[3] == 40, "");
constexpr int addThreeElements(const int v[3]) {
return v[0] + v[1] + v[2];
}
constexpr int is[] = {10, 20, 30 };
static_assert(addThreeElements(is) == 60, "");
struct fred {
char s [6];
int n;
};
struct fred y [] = { [0] = { .s[0] = 'q' } };
#pragma clang diagnostic pop
namespace indices {
constexpr int first[] = {1};
constexpr int firstValue = first[2]; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot refer to element 2 of array of 1}}
constexpr int second[10] = {17};
constexpr int secondValue = second[10];// both-error {{must be initialized by a constant expression}} \
// both-note {{read of dereferenced one-past-the-end pointer}} \
constexpr int negative = second[-2]; // both-error {{must be initialized by a constant expression}} \
// both-note {{cannot refer to element -2 of array of 10}}
};
namespace DefaultInit {
template <typename T, unsigned N>
struct B {
T a[N];
};
int f() {
constexpr B<int,10> arr = {};
constexpr int x = arr.a[0];
}
};
class A {
public:
int a;
constexpr A(int m = 2) : a(10 + m) {}
};
class AU {
public:
int a;
constexpr AU() : a(5 / 0) {} // both-warning {{division by zero is undefined}} \
// both-note 2{{division by zero}} \
// both-error {{never produces a constant expression}}
};
class B {
public:
A a[2];
constexpr B() {}
};
constexpr B b;
static_assert(b.a[0].a == 12, "");
static_assert(b.a[1].a == 12, "");
class BU {
public:
AU a[2];
constexpr BU() {} // both-note {{in call to 'AU()'}}
};
constexpr BU bu; // both-error {{must be initialized by a constant expression}} \
// both-note {{in call to 'BU()'}}
namespace IncDec {
constexpr int getNextElem(const int *A, int I) {
const int *B = (A + I);
++B;
return *B;
}
constexpr int E[] = {1,2,3,4};
static_assert(getNextElem(E, 1) == 3, "");
constexpr int getFirst() {
const int *e = E;
return *(e++);
}
static_assert(getFirst() == 1, "");
constexpr int getFirst2() {
const int *e = E;
e++;
return *e;
}
static_assert(getFirst2() == 2, "");
constexpr int getSecond() {
const int *e = E;
return *(++e);
}
static_assert(getSecond() == 2, "");
constexpr int getSecond2() {
const int *e = E;
++e;
return *e;
}
static_assert(getSecond2() == 2, "");
constexpr int getLast() {
const int *e = E + 3;
return *(e--);
}
static_assert(getLast() == 4, "");
constexpr int getLast2() {
const int *e = E + 3;
e--;
return *e;
}
static_assert(getLast2() == 3, "");
constexpr int getSecondToLast() {
const int *e = E + 3;
return *(--e);
}
static_assert(getSecondToLast() == 3, "");
constexpr int getSecondToLast2() {
const int *e = E + 3;
--e;
return *e;
}
static_assert(getSecondToLast2() == 3, "");
constexpr int bad1() { // both-error {{never produces a constant expression}}
const int *e = E + 3;
e++; // This is fine because it's a one-past-the-end pointer
return *e; // both-note 2{{read of dereferenced one-past-the-end pointer}}
}
static_assert(bad1() == 0, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
constexpr int bad2() { // both-error {{never produces a constant expression}}
const int *e = E + 4;
e++; // both-note 2{{cannot refer to element 5 of array of 4 elements}}
return *e; // This is UB as well
}
static_assert(bad2() == 0, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
constexpr int bad3() { // both-error {{never produces a constant expression}}
const int *e = E;
e--; // both-note 2{{cannot refer to element -1 of array of 4 elements}}
return *e; // This is UB as well
}
static_assert(bad3() == 0, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
constexpr int nullptr1(bool Pre) {
int *a = nullptr;
if (Pre)
++a; // both-note {{arithmetic on null pointer}}
else
a++; // both-note {{arithmetic on null pointer}}
return 1;
}
static_assert(nullptr1(true) == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
static_assert(nullptr1(false) == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
};
namespace ZeroInit {
struct A {
int *p[2];
};
constexpr A a = {};
static_assert(a.p[0] == nullptr, "");
static_assert(a.p[1] == nullptr, "");
struct B {
double f[2];
};
constexpr B b = {};
static_assert(b.f[0] == 0.0, "");
static_assert(b.f[1] == 0.0, "");
}
namespace ArrayInitLoop {
struct X {
int arr[3];
};
constexpr X f(int &r) {
return {++r, ++r, ++r};
}
constexpr int g() {
int n = 0;
auto [a, b, c] = f(n).arr;
return a + b + c;
}
static_assert(g() == 6, "");
}
namespace StringZeroFill {
struct A {
char c[6];
};
constexpr A a = { "abc" };
static_assert(a.c[0] == 'a', "");
static_assert(a.c[1] == 'b', "");
static_assert(a.c[2] == 'c', "");
static_assert(a.c[3] == '\0', "");
static_assert(a.c[4] == '\0', "");
static_assert(a.c[5] == '\0', "");
constexpr char b[6] = "foo";
static_assert(b[0] == 'f', "");
static_assert(b[1] == 'o', "");
static_assert(b[2] == 'o', "");
static_assert(b[3] == '\0', "");
static_assert(b[4] == '\0', "");
static_assert(b[5] == '\0', "");
}
namespace NoInitMapLeak {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdivision-by-zero"
#pragma clang diagnostic ignored "-Wc++20-extensions"
constexpr int testLeak() { // both-error {{never produces a constant expression}}
int a[2];
a[0] = 1;
// interrupts interpretation.
(void)(1 / 0); // both-note 2{{division by zero}}
return 1;
}
#pragma clang diagnostic pop
static_assert(testLeak() == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to 'testLeak()'}}
constexpr int a[] = {1,2,3,4/0,5}; // both-error {{must be initialized by a constant expression}} \
// both-note {{division by zero}} \
// ref-note {{declared here}}
/// FIXME: This should fail in the new interpreter as well.
constexpr int b = a[0]; // ref-error {{must be initialized by a constant expression}} \
// ref-note {{is not a constant expression}} \
// ref-note {{declared here}}
static_assert(b == 1, ""); // ref-error {{not an integral constant expression}} \
// ref-note {{not a constant expression}}
constexpr int f() { // both-error {{never produces a constant expression}}
int a[] = {19,2,3/0,4}; // both-note 2{{division by zero}} \
// both-warning {{is undefined}}
return 1;
}
static_assert(f() == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
}
namespace Incomplete {
struct Foo {
char c;
int a[];
};
constexpr Foo F{};
constexpr const int *A = F.a; // both-error {{must be initialized by a constant expression}} \
// both-note {{array-to-pointer decay of array member without known bound}}
constexpr const int *B = F.a + 1; // both-error {{must be initialized by a constant expression}} \
// both-note {{array-to-pointer decay of array member without known bound}}
constexpr int C = *F.a; // both-error {{must be initialized by a constant expression}} \
// both-note {{array-to-pointer decay of array member without known bound}}
struct X {
int a;
int b[];
};
extern X x;
constexpr int *xb = x.b; // both-error {{must be initialized by a constant expression}} \
// both-note {{array-to-pointer decay of array member without known bound}}
/// These are from test/SemaCXX/constant-expression-cxx11.cpp
extern int arr[];
constexpr int *c = &arr[1]; // both-error {{must be initialized by a constant expression}} \
// both-note {{indexing of array without known bound}}
constexpr int *d = &arr[1]; // both-error {{must be initialized by a constant expression}} \
// both-note {{indexing of array without known bound}}
constexpr int *e = arr + 1; // both-error {{must be initialized by a constant expression}} \
// both-note {{indexing of array without known bound}}
}
namespace GH69115 {
/// This used to crash because we were trying to emit destructors for the
/// array.
constexpr int foo() {
int arr[2][2] = {1, 2, 3, 4};
return 0;
}
static_assert(foo() == 0, "");
/// Test that we still emit the destructors for multi-dimensional
/// composite arrays.
#if __cplusplus >= 202002L
constexpr void assert(bool C) {
if (C)
return;
// Invalid in constexpr.
(void)(1 / 0); // both-warning {{undefined}}
}
class F {
public:
int a;
int *dtor;
int &idx;
constexpr F(int a, int *dtor, int &idx) : a(a), dtor(dtor), idx(idx) {}
constexpr ~F() noexcept(false){
dtor[idx] = a;
++idx;
}
};
constexpr int foo2() {
int dtorIndices[] = {0, 0, 0, 0};
int idx = 0;
{
F arr[2][2] = {F(1, dtorIndices, idx),
F(2, dtorIndices, idx),
F(3, dtorIndices, idx),
F(4, dtorIndices, idx)};
}
/// Reverse-reverse order.
assert(idx == 4);
assert(dtorIndices[0] == 4);
assert(dtorIndices[1] == 3);
assert(dtorIndices[2] == 2);
assert(dtorIndices[3] == 1);
return 0;
}
static_assert(foo2() == 0, "");
#endif
}
namespace NonConstReads {
#if __cplusplus >= 202002L
void *p = nullptr; // both-note {{declared here}}
int arr[!p]; // both-error {{not allowed at file scope}} \
// both-warning {{variable length arrays}} \
// both-note {{read of non-constexpr variable 'p'}}
int z; // both-note {{declared here}}
int a[z]; // both-error {{not allowed at file scope}} \
// both-warning {{variable length arrays}} \
// both-note {{read of non-const variable 'z'}}
#else
void *p = nullptr;
int arr[!p]; // both-error {{not allowed at file scope}}
int z;
int a[z]; // both-error {{not allowed at file scope}}
#endif
const int y = 0;
int yy[y];
}
namespace SelfComparison {
struct S {
int field;
static int static_field;
int array[4];
};
struct T {
int field;
static int static_field;
int array[4];
S s;
};
int struct_test(S s1, S s2, S *s3, T t) {
return s3->array[t.field] == s3->array[t.field]; // both-warning {{self-comparison always evaluates to true}}
};
}
namespace LocalIndex {
void test() {
const int const_subscript = 3;
int array[2]; // both-note {{declared here}}
array[const_subscript] = 0; // both-warning {{array index 3 is past the end of the array (that has type 'int[2]')}}
}
}
namespace LocalVLA {
struct Foo {
int x;
Foo(int x) : x(x) {}
};
struct Elidable {
Elidable();
};
void foo(int size) {
Elidable elidableDynArray[size];
#if __cplusplus >= 202002L
// both-note@-3 {{declared here}}
// both-warning@-3 {{variable length array}}
// both-note@-4 {{function parameter 'size' with unknown value}}
#endif
}
void f (unsigned int m) {
int e[2][m];
#if __cplusplus >= 202002L
// both-note@-3 {{declared here}}
// both-warning@-3 2{{variable length array}}
// both-note@-4 {{function parameter 'm' with unknown value}}
#endif
e[0][0] = 0;
}
}
char melchizedek[2];
typedef decltype(melchizedek[1] - melchizedek[0]) ptrdiff_t;
constexpr ptrdiff_t d1 = &melchizedek[1] - &melchizedek[0]; // ok
constexpr ptrdiff_t d3 = &melchizedek[0] - &melchizedek[1]; // ok
/// GH#88018
const int SZA[] = {};
void testZeroSizedArrayAccess() { unsigned c = SZA[4]; }
#if __cplusplus >= 202002L
constexpr int test_multiarray2() { // both-error {{never produces a constant expression}}
int multi2[2][1]; // both-note {{declared here}}
return multi2[2][0]; // both-note {{cannot access array element of pointer past the end of object}} \
// both-warning {{array index 2 is past the end of the array (that has type 'int[2][1]')}}
}
/// Same but with a dummy pointer.
int multi22[2][2]; // both-note {{declared here}}
int test_multiarray22() {
return multi22[2][0]; // both-warning {{array index 2 is past the end of the array (that has type 'int[2][2]')}}
}
#endif
namespace ArrayMemberAccess {
struct A {
int x;
};
void f(const A (&a)[]) {
bool cond = a->x;
}
}
namespace OnePastEndSub {
struct A {};
constexpr A a[3][3];
constexpr int diff2 = &a[1][3] - &a[1][0]; /// Used to crash.
}
static int same_entity_2[3];
constexpr int *get2() {
// This is a redeclaration of the same entity, even though it doesn't
// inherit the type of the prior declaration.
extern int same_entity_2[];
return same_entity_2;
}
static_assert(get2() == same_entity_2, "failed to find previous decl");
constexpr int zs[2][2][2][2] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
constexpr int fail(const int &p) {
return (&p)[64]; // both-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, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
namespace ZeroSizeTypes {
constexpr int (*p1)[0] = 0, (*p2)[0] = 0;
constexpr int k = p2 - p1; // both-error {{constexpr variable 'k' must be initialized by a constant expression}} \
// both-note {{subtraction of pointers to type 'int[0]' of zero size}} \
// both-warning {{subtraction of pointers to type 'int[0]' of zero size has undefined behavior}}
int arr[5][0];
constexpr int f() { // both-error {{never produces a constant expression}}
return &arr[3] - &arr[0]; // both-note {{subtraction of pointers to type 'int[0]' of zero size}} \
// both-warning {{subtraction of pointers to type 'int[0]' of zero size has undefined behavior}}
}
}
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