1// RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 -pedantic %s
2// C++ [expr.const]p1:
3//   In several places, C++ requires expressions that evaluate to an integral
4//   or enumeration constant: as array bounds, as case expressions, as
5//   bit-field lengths, as enumerator initializers, as static member
6//   initializers, and as integral or enumeration non-type template arguments.
7//   An integral constant-expression can involve only literals, enumerators,
8//   const variables or static data members of integral or enumeration types
9//   initialized with constant expressions, and sizeof expressions. Floating
10//   literals can appear only if they are cast to integral or enumeration types.
11
12enum Enum { eval = 1 };
13const int cval = 2;
14const Enum ceval = eval;
15struct Struct {
16  static const int sval = 3;
17  static const Enum seval = eval;
18};
19
20template <int itval, Enum etval> struct C {
21  enum E {
22    v1 = 1,
23    v2 = eval,
24    v3 = cval,
25    v4 = ceval,
26    v5 = Struct::sval,
27    v6 = Struct::seval,
28    v7 = itval,
29    v8 = etval,
30    v9 = (int)1.5,
31    v10 = sizeof(Struct),
32    v11 = true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 0
33  };
34  unsigned
35    b1 : 1,
36    b2 : eval,
37    b3 : cval,
38    b4 : ceval,
39    b5 : Struct::sval,
40    b6 : Struct::seval,
41    b7 : itval,
42    b8 : etval,
43    b9 : (int)1.5,
44    b10 : sizeof(Struct),
45    b11 : true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 0
46    ;
47  static const int
48    i1 = 1,
49    i2 = eval,
50    i3 = cval,
51    i4 = ceval,
52    i5 = Struct::sval,
53    i6 = Struct::seval,
54    i7 = itval,
55    i8 = etval,
56    i9 = (int)1.5,
57    i10 = sizeof(Struct),
58    i11 = true? 1 + cval * Struct::sval ^ itval / (int)1.5 - sizeof(Struct) : 0
59    ;
60  void f(int cond) {
61    switch(cond) {
62    case    0 + 1:
63    case  100 + eval:
64    case  200 + cval:
65    case  300 + ceval:
66    case  400 + Struct::sval:
67    case  500 + Struct::seval:
68    case  600 + itval:
69    case  700 + etval:
70    case  800 + (int)1.5:
71    case  900 + sizeof(Struct):
72    case 1000 + (true? 1 + cval * Struct::sval ^
73                 itval / (int)1.5 - sizeof(Struct) : 0):
74      ;
75    }
76  }
77  typedef C<itval, etval> T0;
78};
79
80template struct C<1, eval>;
81template struct C<cval, ceval>;
82template struct C<Struct::sval, Struct::seval>;
83
84enum {
85  a = sizeof(int) == 8,
86  b = a? 8 : 4
87};
88
89void diags(int n) {
90  switch (n) {
91    case (1/0, 1): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}
92    case (int)(1/0, 2.0): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}
93    case __imag(1/0): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}
94    case (int)__imag((double)(1/0)): // expected-error {{not an integral constant expression}} expected-note {{division by zero}}
95      ;
96  }
97}
98
99namespace IntOrEnum {
100  const int k = 0;
101  const int &p = k;
102  template<int n> struct S {};
103  S<p> s; // expected-error {{not an integral constant expression}}
104}
105
106extern const int recurse1;
107// recurse2 cannot be used in a constant expression because it is not
108// initialized by a constant expression. The same expression appearing later in
109// the TU would be a constant expression, but here it is not.
110const int recurse2 = recurse1;
111const int recurse1 = 1;
112int array1[recurse1]; // ok
113int array2[recurse2]; // expected-warning {{variable length array}} expected-warning {{integer constant expression}}
114
115namespace FloatConvert {
116  typedef int a[(int)42.3];
117  typedef int a[(int)42.997];
118  typedef int b[(long long)4e20]; // expected-warning {{variable length}} expected-error {{variable length}} expected-warning {{'long long' is a C++11 extension}}
119}
120
121// PR12626
122namespace test3 {
123  struct X; // expected-note {{forward declaration of 'test3::X'}}
124  struct Y { bool b; X x; }; // expected-error {{field has incomplete type 'test3::X'}}
125  int f() { return Y().b; }
126}
127
128// PR18283
129namespace test4 {
130  template <int> struct A {};
131  int const i = { 42 };
132  // i can be used as non-type template-parameter as "const int x = { 42 };" is
133  // equivalent to "const int x = 42;" as per C++03 8.5/p13.
134  typedef A<i> Ai; // ok
135}
136
137// rdar://16064952
138namespace rdar16064952 {
139  template < typename T > void fn1() {
140   T b;
141   unsigned w = ({int a = b.val[sizeof(0)]; 0; }); // expected-warning {{use of GNU statement expression extension}}
142  }
143}
144