Files
clang-p2996/clang/test/SemaTemplate/dependent-expr.cpp
Jun Zhang 8a4d388c7f [Clang][Sema] Prohibit statement expression in the default argument
As statement expression makes no sense in the default argument,
this patch tries to disable it in the all cases.

Please note that the statement expression is a GNU extension, which
means that Clang should be consistent with GCC. However, there's no
response from GCC devs since we have raised the issue for several weeks.
In this case, I think we can disallow statement expressions as a default
parameter in general for now, and relax the restriction if GCC folks
decide to retain the feature for functions but not lambdas in the
future.

Related discussion: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104765

Fixes https://github.com/llvm/llvm-project/issues/53488

Differential Revision: https://reviews.llvm.org/D119609
2022-04-06 09:28:20 +08:00

168 lines
3.6 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s
// PR5908
template <typename Iterator>
void Test(Iterator it) {
*(it += 1);
}
namespace PR6045 {
template<unsigned int r>
class A
{
static const unsigned int member = r;
void f();
};
template<unsigned int r>
const unsigned int A<r>::member;
template<unsigned int r>
void A<r>::f()
{
unsigned k;
(void)(k % member);
}
}
namespace PR7198 {
struct A
{
~A() { }
};
template<typename T>
struct B {
struct C : A {};
void f()
{
C c = C();
}
};
}
namespace PR7724 {
template<typename OT> int myMethod()
{ return 2 && sizeof(OT); }
}
namespace test4 {
template <typename T> T *addressof(T &v) {
return reinterpret_cast<T*>(
&const_cast<char&>(reinterpret_cast<const volatile char &>(v)));
}
}
namespace test5 {
template <typename T> class chained_map {
int k;
void lookup() const {
int &v = (int &)k;
}
};
}
namespace test6 {
template<typename T> T f() {
const T &v(0);
return v;
}
int use = f<int>();
}
namespace PR8795 {
template <class _CharT> int test(_CharT t)
{
int data [] = {
sizeof(_CharT) > sizeof(char)
};
return data[0];
}
}
template<typename T> struct CastDependentIntToPointer {
static void* f() {
T *x;
return ((void*)(((unsigned long)(x)|0x1ul)));
}
};
// Regression test for crasher in r194540.
namespace PR10837 {
typedef void t(int);
template<typename> struct A {
void f();
static t g;
};
t *p;
template<typename T> void A<T>::f() {
p = g;
}
template struct A<int>;
}
namespace PR18152 {
template<int N> struct A {
static const int n = {N};
};
template struct A<0>;
}
template<typename T> void stmt_expr_1() {
static_assert( ({ false; }), "" );
}
void stmt_expr_2() {
static_assert( ({ false; }), "" ); // expected-error {{failed}}
}
namespace PR45083 {
struct A { bool x; };
template<typename> struct B : A {
void f() {
const int n = ({ if (x) {} 0; });
}
};
template void B<int>::f();
template<typename> void f() {
decltype(({})) x; // expected-error {{incomplete type}}
}
template void f<int>(); // expected-note {{instantiation of}}
template<typename> auto g() {
auto c = [](auto, int) -> decltype(({})) {};
using T = decltype(c(0.0, 0));
using T = void;
return c(0, 0);
}
using U = decltype(g<int>()); // expected-note {{previous}}
using U = float; // expected-error {{different types ('float' vs 'decltype(g<int>())' (aka 'void'))}}
void h(auto a, decltype(g<char>())*) {} // expected-note {{previous}}
void h(auto a, void *) {} // expected-error {{redefinition}}
}
namespace BindingInStmtExpr {
template<class ...Ts> struct overload : Ts... {
overload(Ts ...ts) : Ts(decltype(ts)(ts))... {}
using Ts::operator()...;
};
template<int> struct N {};
template<class T> auto num_bindings() {
auto f0 = [](auto t, unsigned) { return N<0>(); };
auto f1 = [](auto t, int) -> decltype(({ auto [_1] = t; N<1>(); })) { return {}; };
auto f2 = [](auto t, int) -> decltype(({ auto [_1, _2] = t; N<2>(); })) { return {}; };
auto f3 = [](auto t, int) -> decltype(({ auto [_1, _2, _3] = t; N<3>(); })) { return {}; };
return decltype(overload(f0, f1, f2, f3)(T(), 0))();
}
struct T { int a; int b; };
// Make sure we get a correct, non-dependent type back.
using U = decltype(num_bindings<T>()); // expected-note {{previous}}
using U = N<3>; // expected-error-re {{type alias redefinition with different types ('N<3>' vs {{.*}}N<2>}}
}