// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -pedantic -verify=expected,both %s
// RUN: %clang_cc1 -std=c++14 -fexperimental-new-constant-interpreter -pedantic -verify=expected,both %s
// RUN: %clang_cc1 -std=c++20 -fexperimental-new-constant-interpreter -pedantic -verify=expected,both %s
// RUN: %clang_cc1 -pedantic -verify=ref,both %s
// RUN: %clang_cc1 -pedantic -std=c++14 -verify=ref,both %s
// RUN: %clang_cc1 -pedantic -std=c++20 -verify=ref,both %s
constexpr void doNothing() {}
constexpr int gimme5() {
doNothing();
return 5;
}
static_assert(gimme5() == 5, "");
template<typename T> constexpr T identity(T t) {
static_assert(true, "");
return t;
}
static_assert(identity(true), "");
static_assert(identity(true), ""); /// Compiled bytecode should be cached
static_assert(!identity(false), "");
template<typename A, typename B>
constexpr bool sameSize() {
static_assert(sizeof(A) == sizeof(B), ""); // both-error {{static assertion failed}} \
// both-note {{evaluates to}}
return true;
}
static_assert(sameSize<int, int>(), "");
static_assert(sameSize<unsigned int, int>(), "");
static_assert(sameSize<char, long>(), ""); // both-note {{in instantiation of function template specialization}}
constexpr auto add(int a, int b) -> int {
return identity(a) + identity(b);
}
constexpr int sub(int a, int b) {
return a - b;
}
static_assert(sub(5, 2) == 3, "");
static_assert(sub(0, 5) == -5, "");
constexpr int norm(int n) {
if (n >= 0) {
return identity(n);
}
return -identity(n);
}
static_assert(norm(5) == norm(-5), "");
constexpr int square(int n) {
return norm(n) * norm(n);
}
static_assert(square(2) == 4, "");
constexpr int add_second(int a, int b, bool doAdd = true) {
if (doAdd)
return a + b;
return a;
}
static_assert(add_second(10, 3, true) == 13, "");
static_assert(add_second(10, 3) == 13, "");
static_assert(add_second(300, -20, false) == 300, "");
constexpr int sub(int a, int b, int c) {
return a - b - c;
}
static_assert(sub(10, 8, 2) == 0, "");
constexpr int recursion(int i) {
doNothing();
i = i - 1;
if (i == 0)
return identity(0);
return recursion(i);
}
static_assert(recursion(10) == 0, "");
template<int N = 5>
constexpr decltype(N) getNum() {
return N;
}
static_assert(getNum<-2>() == -2, "");
static_assert(getNum<10>() == 10, "");
static_assert(getNum() == 5, "");
constexpr int f(); // both-note {{declared here}}
static_assert(f() == 5, ""); // both-error {{not an integral constant expression}} \
// both-note {{undefined function 'f'}}
constexpr int a() {
return f();
}
constexpr int f() {
return 5;
}
static_assert(a() == 5, "");
constexpr int invalid() {
// Invalid expression in visit().
while(huh) {} // both-error {{use of undeclared identifier}}
return 0;
}
constexpr void invalid2() {
int i = 0;
// Invalid expression in discard().
huh(); // both-error {{use of undeclared identifier}}
}
namespace FunctionPointers {
constexpr int add(int a, int b) {
return a + b;
}
struct S { int a; };
constexpr S getS() {
return S{12};
}
constexpr int applyBinOp(int a, int b, int (*op)(int, int)) {
return op(a, b); // both-note {{evaluates to a null function pointer}}
}
static_assert(applyBinOp(1, 2, add) == 3, "");
static_assert(applyBinOp(1, 2, nullptr) == 3, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
constexpr int ignoreReturnValue() {
int (*foo)(int, int) = add;
foo(1, 2);
return 1;
}
static_assert(ignoreReturnValue() == 1, "");
constexpr int createS(S (*gimme)()) {
gimme(); // Ignored return value
return gimme().a;
}
static_assert(createS(getS) == 12, "");
namespace FunctionReturnType {
typedef int (*ptr)(int*);
typedef ptr (*pm)();
constexpr int fun1(int* y) {
return *y + 10;
}
constexpr ptr fun() {
return &fun1;
}
static_assert(fun() == nullptr, ""); // both-error {{static assertion failed}}
constexpr int foo() {
int (*f)(int *) = fun();
int m = 0;
m = f(&m);
return m;
}
static_assert(foo() == 10, "");
struct S {
int i;
void (*fp)();
};
constexpr S s{ 12 };
static_assert(s.fp == nullptr, ""); // zero-initialized function pointer.
constexpr int (*op)(int, int) = add;
constexpr bool b = op;
static_assert(op, "");
static_assert(!!op, "");
constexpr int (*op2)(int, int) = nullptr;
static_assert(!op2, "");
int m() { return 5;} // both-note {{declared here}}
constexpr int (*invalidFnPtr)() = m;
static_assert(invalidFnPtr() == 5, ""); // both-error {{not an integral constant expression}} \
// both-note {{non-constexpr function 'm'}}
namespace ToBool {
void mismatched(int x) {}
typedef void (*callback_t)(int);
void foo() {
callback_t callback = (callback_t)mismatched; // warns
/// Casts a function pointer to a boolean and then back to a function pointer.
/// This is extracted from test/Sema/callingconv-cast.c
callback = (callback_t)!mismatched; // both-warning {{address of function 'mismatched' will always evaluate to 'true'}} \
// both-note {{prefix with the address-of operator to silence this warning}}
}
}
}
namespace Comparison {
void f(), g();
constexpr void (*pf)() = &f, (*pg)() = &g;
constexpr bool u13 = pf < pg; // both-warning {{ordered comparison of function pointers}} \
// both-error {{must be initialized by a constant expression}} \
// both-note {{comparison between '&f' and '&g' has unspecified value}}
constexpr bool u14 = pf < (void(*)())nullptr; // both-warning {{ordered comparison of function pointers}} \
// both-error {{must be initialized by a constant expression}} \
// both-note {{comparison between '&f' and 'nullptr' has unspecified value}}
static_assert(pf != pg, "");
static_assert(pf == &f, "");
static_assert(pg == &g, "");
}
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); } // both-note {{'F' evaluates to a null function pointer}}
constexpr int Invalid = Apply(Select(0), 0); // both-error {{must be initialized by a constant expression}} \
// both-note {{in call to 'Apply(nullptr, 0)'}}
}
struct F {
constexpr bool ok() const {
return okRecurse();
}
constexpr bool okRecurse() const {
return true;
}
};
struct BodylessMemberFunction {
constexpr int first() const {
return second();
}
constexpr int second() const {
return 1;
}
};
constexpr int nyd(int m);
constexpr int doit() { return nyd(10); }
constexpr int nyd(int m) { return m; }
static_assert(doit() == 10, "");
namespace InvalidCall {
struct S {
constexpr int a() const { // both-error {{never produces a constant expression}}
return 1 / 0; // both-note 2{{division by zero}} \
// both-warning {{is undefined}}
}
};
constexpr S s;
static_assert(s.a() == 1, ""); // both-error {{not an integral constant expression}} \
// both-note {{in call to}}
/// This used to cause an assertion failure in the new constant interpreter.
constexpr void func(); // both-note {{declared here}}
struct SS {
constexpr SS() { func(); } // both-note {{undefined function }}
};
constexpr SS ss; // both-error {{must be initialized by a constant expression}} \
// both-note {{in call to 'SS()'}}
/// This should not emit a diagnostic.
constexpr int f();
constexpr int a() {
return f();
}
constexpr int f() {
return 5;
}
static_assert(a() == 5, "");
}
namespace CallWithArgs {
/// This used to call problems during checkPotentialConstantExpression() runs.
constexpr void g(int a) {}
constexpr void f() {
g(0);
}
}
namespace ReturnLocalPtr {
constexpr int *p() {
int a = 12;
return &a; // both-warning {{address of stack memory}}
}
/// GCC rejects the expression below, just like the new interpreter. The current interpreter
/// however accepts it and only warns about the function above returning an address to stack
/// memory. If we change the condition to 'p() != nullptr', it even succeeds.
static_assert(p() == nullptr, ""); // ref-error {{static assertion failed}} \
// expected-error {{not an integral constant expression}}
/// FIXME: The current interpreter emits diagnostics in the reference case below, but the
/// new one does not.
constexpr const int &p2() {
int a = 12; // ref-note {{declared here}}
return a; // both-warning {{reference to stack memory associated with local variable}}
}
static_assert(p2() == 12, ""); // both-error {{not an integral constant expression}} \
// ref-note {{read of variable whose lifetime has ended}}
}
namespace VoidReturn {
/// ReturnStmt with an expression in a void function used to cause problems.
constexpr void bar() {}
constexpr void foo() {
return bar();
}
static_assert((foo(),1) == 1, "");
}
namespace InvalidReclRefs {
void param(bool b) { // both-note {{declared here}}
static_assert(b, ""); // both-error {{not an integral constant expression}} \
// both-note {{function parameter 'b' with unknown value}}
static_assert(true ? true : b, "");
}
#if __cplusplus >= 202002L
consteval void param2(bool b) { // both-note {{declared here}}
static_assert(b, ""); // both-error {{not an integral constant expression}} \
// both-note {{function parameter 'b' with unknown value}}
}
#endif
}
namespace TemplateUndefined {
template<typename T> constexpr int consume(T);
// ok, not a constant expression.
const int k = consume(0);
template<typename T> constexpr int consume(T) { return 0; }
// ok, constant expression.
constexpr int l = consume(0);
static_assert(l == 0, "");
}
namespace PtrReturn {
constexpr void *a() {
return nullptr;
}
static_assert(a() == nullptr, "");
}
namespace Variadic {
struct S { int a; bool b; };
constexpr void variadic_function(int a, ...) {}
constexpr int f1() {
variadic_function(1, S{'a', false});
return 1;
}
static_assert(f1() == 1, "");
constexpr int variadic_function2(...) {
return 12;
}
static_assert(variadic_function2() == 12, "");
static_assert(variadic_function2(1, 2, 3, 4, 5) == 12, "");
static_assert(variadic_function2(1, variadic_function2()) == 12, "");
constexpr int (*VFP)(...) = variadic_function2;
static_assert(VFP() == 12, "");
/// Member functions
struct Foo {
int a = 0;
constexpr void bla(...) {}
constexpr S bla2(...) {
return S{12, true};
}
constexpr Foo(...) : a(1337) {}
constexpr Foo(void *c, bool b, void*p, ...) : a('a' + b) {}
constexpr Foo(int a, const S* s, ...) : a(a) {}
};
constexpr int foo2() {
Foo f(1, nullptr);
auto s = f.bla2(1, 2, S{1, false});
return s.a + s.b;
}
static_assert(foo2() == 13, "");
constexpr Foo _f = 123;
static_assert(_f.a == 1337, "");
constexpr Foo __f(nullptr, false, nullptr, nullptr, 'a', Foo());
static_assert(__f.a == 'a', "");
#if __cplusplus >= 202002L
namespace VariadicVirtual {
class A {
public:
constexpr virtual void foo(int &a, ...) {
a = 1;
}
};
class B : public A {
public:
constexpr void foo(int &a, ...) override {
a = 2;
}
};
constexpr int foo() {
B b;
int a;
b.foo(a, 1,2,nullptr);
return a;
}
static_assert(foo() == 2, "");
} // VariadicVirtual
namespace VariadicQualified {
class A {
public:
constexpr virtual int foo(...) const {
return 5;
}
};
class B : public A {};
class C : public B {
public:
constexpr int foo(...) const override {
return B::foo(1,2,3); // B doesn't have a foo(), so this should call A::foo().
}
constexpr int foo2() const {
return this->A::foo(1,2,3,this);
}
};
constexpr C c;
static_assert(c.foo() == 5);
static_assert(c.foo2() == 5);
} // VariadicQualified
#endif
}
namespace Packs {
template<typename...T>
constexpr int foo() { return sizeof...(T); }
static_assert(foo<int, char>() == 2, "");
static_assert(foo<>() == 0, "");
}
namespace AddressOf {
struct S {} s;
static_assert(__builtin_addressof(s) == &s, "");
struct T { constexpr T *operator&() const { return nullptr; } int n; } t;
constexpr T *pt = __builtin_addressof(t);
static_assert(&pt->n == &t.n, "");
struct U { int n : 5; } u;
int *pbf = __builtin_addressof(u.n); // both-error {{address of bit-field requested}}
S *ptmp = __builtin_addressof(S{}); // both-error {{taking the address of a temporary}} \
// both-warning {{temporary whose address is used as value of local variable 'ptmp' will be destroyed at the end of the full-expression}}
constexpr int foo() {return 1;}
static_assert(__builtin_addressof(foo) == foo, "");
constexpr _Complex float F = {3, 4}; // both-warning {{'_Complex' is a C99 extension}}
static_assert(__builtin_addressof(F) == &F, "");
void testAddressof(int x) {
static_assert(&x == __builtin_addressof(x), "");
}
}
namespace std {
template <typename T> struct remove_reference { using type = T; };
template <typename T> struct remove_reference<T &> { using type = T; };
template <typename T> struct remove_reference<T &&> { using type = T; };
template <typename T>
constexpr typename std::remove_reference<T>::type&& move(T &&t) noexcept {
return static_cast<typename std::remove_reference<T>::type &&>(t);
}
}
/// The std::move declaration above gets translated to a builtin function.
namespace Move {
#if __cplusplus >= 202002L
consteval int f_eval() { // both-note 12{{declared here}}
return 0;
}
/// From test/SemaCXX/cxx2a-consteval.
struct Copy {
int(*ptr)();
constexpr Copy(int(*p)() = nullptr) : ptr(p) {}
consteval Copy(const Copy&) = default;
};
constexpr const Copy &to_lvalue_ref(const Copy &&a) {
return a;
}
void test() {
constexpr const Copy C;
// there is no the copy constructor call when its argument is a prvalue because of garanteed copy elision.
// so we need to test with both prvalue and xvalues.
{ Copy c(C); }
{ Copy c((Copy(&f_eval))); } // both-error {{cannot take address of consteval}}
{ Copy c(std::move(C)); }
{ Copy c(std::move(Copy(&f_eval))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c(to_lvalue_ref((Copy(&f_eval)))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c(to_lvalue_ref(std::move(C))); }
{ Copy c(to_lvalue_ref(std::move(Copy(&f_eval)))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c = Copy(C); }
{ Copy c = Copy(Copy(&f_eval)); } // both-error {{cannot take address of consteval}}
{ Copy c = Copy(std::move(C)); }
{ Copy c = Copy(std::move(Copy(&f_eval))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c = Copy(to_lvalue_ref(Copy(&f_eval))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c = Copy(to_lvalue_ref(std::move(C))); }
{ Copy c = Copy(to_lvalue_ref(std::move(Copy(&f_eval)))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c; c = Copy(C); }
{ Copy c; c = Copy(Copy(&f_eval)); } // both-error {{cannot take address of consteval}}
{ Copy c; c = Copy(std::move(C)); }
{ Copy c; c = Copy(std::move(Copy(&f_eval))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c; c = Copy(to_lvalue_ref(Copy(&f_eval))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
{ Copy c; c = Copy(to_lvalue_ref(std::move(C))); }
{ Copy c; c = Copy(to_lvalue_ref(std::move(Copy(&f_eval)))); } // both-error {{is not a constant expression}} \
// both-note {{to a consteval}}
}
#endif
constexpr int A = std::move(5);
static_assert(A == 5, "");
}
namespace StaticLocals {
void test() {
static int j; // both-note {{declared here}}
static_assert(&j != nullptr, ""); // both-warning {{always true}}
static_assert(j == 0, ""); // both-error {{not an integral constant expression}} \
// both-note {{read of non-const variable 'j'}}
static int k = 0; // both-note {{declared here}}
static_assert(k == 0, ""); // both-error {{not an integral constant expression}} \
// both-note {{read of non-const variable 'k'}}
static const int l = 12;
static_assert(l == 12, "");
static const int m; // both-error {{default initialization}}
static_assert(m == 0, "");
}
}
namespace Local {
/// We used to run into infinite recursin here because we were
/// trying to evaluate t's initializer while evaluating t's initializer.
int a() {
const int t=t;
return t;
}
}
namespace VariadicOperator {
struct Callable {
float& operator()(...);
};
void test_callable(Callable c) {
float &fr = c(10);
}
}
namespace WeakCompare {
[[gnu::weak]]void weak_method();
static_assert(weak_method != nullptr, ""); // both-error {{not an integral constant expression}} \
// both-note {{comparison against address of weak declaration '&weak_method' can only be performed at runtim}}
constexpr auto A = &weak_method;
static_assert(A != nullptr, ""); // both-error {{not an integral constant expression}} \
// both-note {{comparison against address of weak declaration '&weak_method' can only be performed at runtim}}
}
namespace FromIntegral {
#if __cplusplus >= 202002L
typedef double (*DoubleFn)();
int a[(int)DoubleFn((void*)-1)()]; // both-error {{not allowed at file scope}} \
// both-warning {{variable length arrays}}
int b[(int)DoubleFn((void*)(-1 + 1))()]; // both-error {{not allowed at file scope}} \
// expected-note {{evaluates to a null function pointer}} \
// both-warning {{variable length arrays}}
#endif
}
namespace {
template <typename T> using id = T;
template <typename T>
constexpr void g() {
constexpr id<void (T)> f;
}
static_assert((g<int>(), true), "");
}
namespace {
/// The InitListExpr here is of void type.
void bir [[clang::annotate("B", {1, 2, 3, 4})]] (); // both-error {{'annotate' attribute requires parameter 1 to be a constant expression}} \
// both-note {{subexpression not valid in a constant expression}}
}
namespace FuncPtrParam {
void foo(int(&a)()) {
*a; // both-warning {{expression result unused}}
}
}
namespace {
void f() noexcept;
void (&r)() = f;
void (&cond3)() = r;
}
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)()]; // both-error {{variable length array}} \
// both-warning {{are a Clang extension}}
int b[(int)IntFn(f)()]; // ok
}
#if __cplusplus >= 202002L
namespace StableAddress {
template<unsigned N> struct str {
char arr[N];
};
// FIXME: Deduction guide not needed with P1816R0.
template<unsigned N> str(const char (&)[N]) -> str<N>;
template<str s> constexpr int sum() {
int n = 0;
for (char c : s.arr)
n += c;
return n;
}
static_assert(sum<str{"$hello $world."}>() == 1234, "");
}
#endif
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