p5.cpp revision d5bc867f6597ee8d4eb31ea217934e436fc7c7e3 
1// RUN: %clang_cc1 -fsyntax-only -verify %s
2
3//   A program that calls for default-initialization or value-initialization of
4//   an entity of reference type is illformed. If T is a cv-qualified type, the
5//   cv-unqualified version of T is used for these definitions of
6//   zero-initialization, default-initialization, and value-initialization.
7
8struct S { // expected-error {{implicit default constructor for 'S' must explicitly initialize the reference member}}
9  int &x; // expected-note {{declared here}} expected-error 3{{reference to type 'int' requires an initializer}}
10};
11S s; // expected-note {{implicit default constructor for 'S' first required here}}
12S f() {
13  return S(); // expected-note {{in value-initialization of type 'S' here}}
14}
15
16struct T
17  : S { // expected-note 2{{in value-initialization of type 'S' here}}
18};
19T t = T(); // expected-note {{in value-initialization of type 'T' here}}
20
21struct U {
22  T t[3]; // expected-note {{in value-initialization of type 'T' here}}
23};
24U u = U(); // expected-note {{in value-initialization of type 'U' here}}
25
26// Ensure that we handle C++11 in-class initializers properly as an extension.
27// In this case, there is no user-declared default constructor, so we
28// recursively apply the value-initialization checks, but we will emit a
29// constructor call anyway, because the default constructor is not trivial.
30struct V {
31  int n;
32  int &r = n; // expected-warning {{C++11}}
33};
34V v = V(); // ok
35struct W {
36  int n;
37  S s = { n }; // expected-warning {{C++11}}
38};
39W w = W(); // ok
40
41// Ensure we're not faking this up by making the default constructor
42// non-trivial.
43#define static_assert(B, S) typedef int assert_failed[(B) ? 1 : -1];
44static_assert(__has_trivial_constructor(S), "");
45static_assert(__has_trivial_constructor(T), "");
46static_assert(__has_trivial_constructor(U), "");
47static_assert(!__has_trivial_constructor(V), "");
48static_assert(!__has_trivial_constructor(W), "");
49