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      1 // RUN: %clang_cc1 %s -std=c++11 -fsyntax-only -verify -triple x86_64-linux-gnu
      2 
      3 struct S;
      4 constexpr int extract(const S &s);
      5 
      6 struct S {
      7   constexpr S() : n(extract(*this)), m(0) {} // expected-note {{in call to 'extract(s1)'}}
      8   constexpr S(int k) : n(k), m(extract(*this)) {}
      9   int n, m;
     10 };
     11 
     12 constexpr int extract(const S &s) { return s.n; } // expected-note {{read of object outside its lifetime is not allowed in a constant expression}}
     13 
     14 constexpr S s1; // ok
     15 void f() {
     16   constexpr S s1; // expected-error {{constant expression}} expected-note {{in call to 'S()'}}
     17   constexpr S s2(10);
     18 }
     19 
     20 typedef __attribute__((vector_size(16))) int vector_int;
     21 
     22 struct T {
     23   constexpr T() : arr() {}
     24   int arr[4];
     25 };
     26 struct U : T {
     27   constexpr U(const int *p) : T(), another(), p(p) {}
     28   constexpr U(const U &u) : T(), another(), p(u.p) {}
     29   T another;
     30   const int *p;
     31 };
     32 constexpr U u1(&u1.arr[2]);
     33 
     34 constexpr int test_printing(int a, float b, _Complex int c, _Complex float d,
     35                             int *e, int &f, vector_int g, U h) {
     36   return *e; // expected-note {{read of non-constexpr variable 'u2'}}
     37 }
     38 U u2(0); // expected-note {{here}}
     39 static_assert(test_printing(12, 39.762, 3 + 4i, 12.9 + 3.6i, &u2.arr[4], u2.another.arr[2], (vector_int){5, 1, 2, 3}, u1) == 0, ""); // \
     40 expected-error {{constant expression}} \
     41 expected-note {{in call to 'test_printing(12, 3.976200e+01, 3+4i, 1.290000e+01+3.600000e+00i, &u2.T::arr[4], u2.another.arr[2], {5, 1, 2, 3}, {{{}}, {{}}, &u1.T::arr[2]})'}}
     42 
     43 struct V {
     44   // FIXME: when we can generate these as constexpr constructors, remove the
     45   // explicit definitions.
     46   constexpr V() : arr{[255] = 42} {}
     47   constexpr V(const V &v) : arr{[255] = 42} {}
     48   int arr[256];
     49 };
     50 constexpr V v;
     51 constexpr int get(const int *p) { return *p; } // expected-note {{read of dereferenced one-past-the-end pointer}}
     52 constexpr int passLargeArray(V v) { return get(v.arr+256); } // expected-note {{in call to 'get(&v.arr[256])'}}
     53 static_assert(passLargeArray(v) == 0, ""); // expected-error {{constant expression}} expected-note {{in call to 'passLargeArray({{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...}})'}}
     54 
     55 union Union {
     56   constexpr Union(int n) : b(n) {}
     57   constexpr Union(const Union &u) : b(u.b) {}
     58   int a, b;
     59 };
     60 constexpr Union myUnion = 76;
     61 
     62 constexpr int badness(Union u) { return u.a + u.b; } // expected-note {{read of member 'a' of union with active member 'b'}}
     63 static_assert(badness(myUnion), ""); // expected-error {{constant expression}} \
     64         expected-note {{in call to 'badness({.b = 76})'}}
     65 
     66 struct MemPtrTest {
     67   int n;
     68   void f();
     69 };
     70 MemPtrTest mpt; // expected-note {{here}}
     71 constexpr int MemPtr(int (MemPtrTest::*a), void (MemPtrTest::*b)(), int &c) {
     72   return c; // expected-note {{read of non-constexpr variable 'mpt'}}
     73 }
     74 static_assert(MemPtr(&MemPtrTest::n, &MemPtrTest::f, mpt.*&MemPtrTest::n), ""); // expected-error {{constant expression}} \
     75 expected-note {{in call to 'MemPtr(&MemPtrTest::n, &MemPtrTest::f, mpt.n)'}}
     76 
     77 template<typename CharT>
     78 constexpr CharT get(const CharT *p) { return p[-1]; } // expected-note 5{{}}
     79 
     80 constexpr char c = get("test\0\\\"\t\a\b\234"); // \
     81   expected-error {{}} expected-note {{"test\000\\\"\t\a\b\234"}}
     82 constexpr char c8 = get(u8"test\0\\\"\t\a\b\234"); // \
     83   expected-error {{}} expected-note {{u8"test\000\\\"\t\a\b\234"}}
     84 constexpr char16_t c16 = get(u"test\0\\\"\t\a\b\234\u1234"); // \
     85   expected-error {{}} expected-note {{u"test\000\\\"\t\a\b\234\u1234"}}
     86 constexpr char32_t c32 = get(U"test\0\\\"\t\a\b\234\u1234\U0010ffff"); // \
     87   expected-error {{}} expected-note {{U"test\000\\\"\t\a\b\234\u1234\U0010FFFF"}}
     88 constexpr wchar_t wc = get(L"test\0\\\"\t\a\b\234\u1234\xffffffff"); // \
     89   expected-error {{}} expected-note {{L"test\000\\\"\t\a\b\234\x1234\xFFFFFFFF"}}
     90 
     91 constexpr char32_t c32_err = get(U"\U00110000"); // expected-error {{invalid universal character}}
     92 
     93 typedef decltype(sizeof(int)) LabelDiffTy;
     94 constexpr LabelDiffTy mulBy3(LabelDiffTy x) { return x * 3; } // expected-note {{subexpression}}
     95 void LabelDiffTest() {
     96   static_assert(mulBy3((LabelDiffTy)&&a-(LabelDiffTy)&&b) == 3, ""); // expected-error {{constant expression}} expected-note {{call to 'mulBy3(&&a - &&b)'}}
     97   a:b:return;
     98 }
     99 
    100 constexpr bool test_bool_printing(bool b) { return 1 / !(2*b | !(2*b)); } // expected-note 2{{division by zero}}
    101 constexpr bool test_bool_0 = test_bool_printing(false); // expected-error {{constant expr}} expected-note {{in call to 'test_bool_printing(false)'}}
    102 constexpr bool test_bool_1 = test_bool_printing(true); // expected-error {{constant expr}} expected-note {{in call to 'test_bool_printing(true)'}}
    103