1 // RUN: %clang_cc1 -fsyntax-only -verify %s 2 int g(int); 3 4 void f() { 5 int i; 6 int &r = i; 7 r = 1; 8 int *p = &r; 9 int &rr = r; 10 int (&rg)(int) = g; 11 rg(i); 12 int a[3]; 13 int (&ra)[3] = a; 14 ra[1] = i; 15 int *Q; 16 int *& P = Q; 17 P[1] = 1; 18 } 19 20 typedef int t[1]; 21 void test2() { 22 t a; 23 t& b = a; 24 25 26 int c[3]; 27 int (&rc)[3] = c; 28 } 29 30 // C++ [dcl.init.ref]p5b1 31 struct A { }; 32 struct B : A { } b; 33 34 void test3() { 35 double d = 2.0; 36 double& rd = d; // rd refers to d 37 const double& rcd = d; // rcd refers to d 38 39 A& ra = b; // ra refers to A subobject in b 40 const A& rca = b; // rca refers to A subobject in b 41 } 42 43 B fB(); 44 45 // C++ [dcl.init.ref]p5b2 46 void test4() { 47 double& rd2 = 2.0; // expected-error{{non-const lvalue reference to type 'double' cannot bind to a temporary of type 'double'}} 48 int i = 2; 49 double& rd3 = i; // expected-error{{non-const lvalue reference to type 'double' cannot bind to a value of unrelated type 'int'}} 50 51 const A& rca = fB(); 52 } 53 54 void test5() { 55 // const double& rcd2 = 2; // rcd2 refers to temporary with value 2.0 56 const volatile int cvi = 1; 57 const int& r = cvi; // expected-error{{binding value of type 'const volatile int' to reference to type 'const int' drops 'volatile' qualifier}} 58 } 59 60 // C++ [dcl.init.ref]p3 61 int& test6(int& x) { 62 int& yo; // expected-error{{declaration of reference variable 'yo' requires an initializer}} 63 64 return x; 65 } 66 int& not_initialized_error; // expected-error{{declaration of reference variable 'not_initialized_error' requires an initializer}} 67 extern int& not_initialized_okay; 68 69 class Test6 { // expected-warning{{class 'Test6' does not declare any constructor to initialize its non-modifiable members}} 70 int& okay; // expected-note{{reference member 'okay' will never be initialized}} 71 }; 72 73 struct C : B, A { }; // expected-warning {{direct base 'A' is inaccessible due to ambiguity:\n struct C -> struct B -> struct A\nstruct C -> struct A}} 74 75 void test7(C& c) { 76 A& a1 = c; // expected-error {{ambiguous conversion from derived class 'C' to base class 'A':}} 77 } 78 79 // C++ [dcl.ref]p1, C++ [dcl.ref]p4 80 void test8(int& const,// expected-error{{'const' qualifier may not be applied to a reference}} 81 82 void&, // expected-error{{cannot form a reference to 'void'}} 83 int& &) // expected-error{{type name declared as a reference to a reference}} 84 { 85 typedef int& intref; 86 typedef intref& intrefref; // C++ DR 106: reference collapsing 87 88 typedef intref const intref_c; // expected-warning {{'const' qualifier on reference type 'intref' (aka 'int &') has no effect}} 89 typedef intref_c intref; // ok, same type 90 91 typedef intref volatile intref; // expected-warning {{'volatile' qualifier on reference type 'intref' (aka 'int &') has no effect}} 92 typedef intref _Atomic intref; // expected-warning {{'_Atomic' qualifier on reference type 'intref' (aka 'int &') has no effect}} 93 94 void restrict_ref(__restrict intref); // ok 95 void restrict_ref(int &__restrict); // ok 96 } 97 98 template<typename T> int const_param(const T) {} 99 int const_ref_param = const_param<int&>(const_ref_param); // no-warning 100 101 102 class string { 103 char *Data; 104 unsigned Length; 105 public: 106 string(); 107 ~string(); 108 }; 109 110 string getInput(); 111 112 void test9() { 113 string &s = getInput(); // expected-error{{lvalue reference}} 114 } 115 116 void test10() { 117 __attribute((vector_size(16))) typedef int vec4; 118 typedef __attribute__(( ext_vector_type(4) )) int ext_vec4; 119 120 vec4 v; 121 int &a = v[0]; // expected-error{{non-const reference cannot bind to vector element}} 122 const int &b = v[0]; 123 124 ext_vec4 ev; 125 int &c = ev.x; // expected-error{{non-const reference cannot bind to vector element}} 126 const int &d = ev.x; 127 } 128 129 namespace PR7149 { 130 template<typename T> struct X0 131 { 132 T& first; 133 X0(T& p1) : first(p1) { } 134 }; 135 136 137 void f() 138 { 139 int p1[1]; 140 X0< const int[1]> c(p1); 141 } 142 } 143 144 namespace PR8608 { 145 bool& f(unsigned char& c) { return (bool&)c; } 146 } 147 148 // The following crashed trying to recursively evaluate the LValue. 149 const int &do_not_crash = do_not_crash; // expected-warning{{reference 'do_not_crash' is not yet bound to a value when used within its own initialization}} 150 151 namespace ExplicitRefInit { 152 // This is invalid: we can't copy-initialize an 'A' temporary using an 153 // explicit constructor. 154 struct A { explicit A(int); }; 155 const A &a(0); // expected-error {{reference to type 'const ExplicitRefInit::A' could not bind to an rvalue of type 'int'}} 156 } 157
