1 // RUN: %clang_cc1 -fsyntax-only -verify %s
2 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
3 int g(int);
4 
5 void f() {
6   int i;
7   int &r = i;
8   r = 1;
9   int *p = &r;
10   int &rr = r;
11   int (&rg)(int) = g;
12   rg(i);
13   int a[3];
14   int (&ra)[3] = a;
15   ra[1] = i;
16   int *Q;
17   int *& P = Q;
18   P[1] = 1;
19 }
20 
21 typedef int t[1];
22 void test2() {
23     t a;
24     t& b = a;
25 
26 
27     int c[3];
28     int (&rc)[3] = c;
29 }
30 
31 // C++ [dcl.init.ref]p5b1
32 struct A { };
33 struct B : A { } b;
34 
35 void test3() {
36   double d = 2.0;
37   double& rd = d; // rd refers to d
38   const double& rcd = d; // rcd refers to d
39 
40   A& ra = b; // ra refers to A subobject in b
41   const A& rca = b; // rca refers to A subobject in b
42 }
43 
44 B fB();
45 
46 // C++ [dcl.init.ref]p5b2
47 void test4() {
48   double& rd2 = 2.0; // expected-error{{non-const lvalue reference to type 'double' cannot bind to a temporary of type 'double'}}
49   int i = 2;
50   double& rd3 = i; // expected-error{{non-const lvalue reference to type 'double' cannot bind to a value of unrelated type 'int'}}
51 
52   const A& rca = fB();
53 }
54 
55 void test5() {
56   //  const double& rcd2 = 2; // rcd2 refers to temporary with value 2.0
57   const volatile int cvi = 1;
58   const int& r = cvi; // expected-error{{binding value of type 'const volatile int' to reference to type 'const int' drops 'volatile' qualifier}}
59 
60 #if __cplusplus >= 201103L
61   const int& r2{cvi}; // expected-error{{binding value of type 'const volatile int' to reference to type 'const int' drops 'volatile' qualifier}}
62 
63   const int a = 2;
64   int& r3{a}; // expected-error{{binding value of type 'const int' to reference to type 'int' drops 'const'}}
65 
66   const int&& r4{a}; // expected-error{{rvalue reference to type 'const int' cannot bind to lvalue of type 'const int'}}
67 
68   void func();
69   void func(int);
70   int &ptr1 = {func}; // expected-error{{address of overloaded function 'func' does not match required type 'int'}}
71   int &&ptr2{func}; // expected-error{{address of overloaded function 'func' does not match required type 'int'}}
72   // expected-note@-4{{candidate function}}
73   // expected-note@-4{{candidate function}}
74   // expected-note@-6{{candidate function}}
75   // expected-note@-6{{candidate function}}
76 #endif
77 }
78 
79 // C++ [dcl.init.ref]p3
80 int& test6(int& x) {
81   int& yo; // expected-error{{declaration of reference variable 'yo' requires an initializer}}
82 
83   return x;
84 }
85 int& not_initialized_error; // expected-error{{declaration of reference variable 'not_initialized_error' requires an initializer}}
86 extern int& not_initialized_okay;
87 
88 class Test6 { // expected-warning{{class 'Test6' does not declare any constructor to initialize its non-modifiable members}}
89   int& okay; // expected-note{{reference member 'okay' will never be initialized}}
90 };
91 
92 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}}
93 
94 void test7(C& c) {
95   A& a1 = c; // expected-error {{ambiguous conversion from derived class 'C' to base class 'A':}}
96 }
97 
98 // C++ [dcl.ref]p1, C++ [dcl.ref]p4
99 void test8(int& const,// expected-error{{'const' qualifier may not be applied to a reference}}
100 
101            void&,     // expected-error{{cannot form a reference to 'void'}}
102            int& &)    // expected-error{{type name declared as a reference to a reference}}
103 {
104   typedef int& intref;
105   typedef intref& intrefref; // C++ DR 106: reference collapsing
106 
107   typedef intref const intref_c; // expected-warning {{'const' qualifier on reference type 'intref' (aka 'int &') has no effect}}
108   typedef intref_c intref; // ok, same type
109 
110   typedef intref volatile intref; // expected-warning {{'volatile' qualifier on reference type 'intref' (aka 'int &') has no effect}}
111   typedef intref _Atomic intref; // expected-warning {{'_Atomic' qualifier on reference type 'intref' (aka 'int &') has no effect}}
112 
113   void restrict_ref(__restrict intref); // ok
114   void restrict_ref(int &__restrict); // ok
115 }
116 
117 template<typename T> int const_param(const T) {}
118 int const_ref_param = const_param<int&>(const_ref_param); // no-warning
119 
120 
121 class string {
122   char *Data;
123   unsigned Length;
124 public:
125   string();
126   ~string();
127 };
128 
129 string getInput();
130 
131 void test9() {
132   string &s = getInput(); // expected-error{{lvalue reference}}
133 }
134 
135 void test10() {
136   __attribute((vector_size(16))) typedef int vec4;
137   typedef __attribute__(( ext_vector_type(4) )) int ext_vec4;
138 
139   vec4 v;
140   int &a = v[0]; // expected-error{{non-const reference cannot bind to vector element}}
141   const int &b = v[0];
142 
143   ext_vec4 ev;
144   int &c = ev.x; // expected-error{{non-const reference cannot bind to vector element}}
145   const int &d = ev.x;
146 }
147 
148 namespace PR7149 {
149   template<typename T> struct X0
150   {
151     T& first;
152     X0(T& p1) : first(p1) { }
153   };
154 
155 
156   void f()
157   {
158     int p1[1];
159     X0< const int[1]> c(p1);
160   }
161 }
162 
163 namespace PR8608 {
164   bool& f(unsigned char& c) { return (bool&)c; }
165 }
166 
167 // The following crashed trying to recursively evaluate the LValue.
168 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}}
169 
170 namespace ExplicitRefInit {
171   // This is invalid: we can't copy-initialize an 'A' temporary using an
172   // explicit constructor.
173   struct A { explicit A(int); };
174   const A &a(0); // expected-error {{reference to type 'const ExplicitRefInit::A' could not bind to an rvalue of type 'int'}}
175 }
176 
177 namespace RefCollapseTypePrinting {
178   template<typename T> void add_lref() {
179     using X = int(T); // expected-note 4{{previous}}
180     using X = const volatile T&;
181     // expected-error@-1 {{'int &' vs 'int (int &)'}}
182     // expected-error@-2 {{'int &' vs 'int (int &&)'}}
183     // expected-error@-3 {{'const int &' vs 'int (const int &)'}}
184     // expected-error@-4 {{'const int &' vs 'int (const int &&)'}}
185   }
186   template void add_lref<int&>(); // expected-note {{instantiation of}}
187   template void add_lref<int&&>(); // expected-note {{instantiation of}}
188   template void add_lref<const int&>(); // expected-note {{instantiation of}}
189   template void add_lref<const int&&>(); // expected-note {{instantiation of}}
190 
191   template<typename T> void add_rref() {
192     using X = int(T); // expected-note 4{{previous}}
193     using X = const volatile T&&;
194     // expected-error@-1 {{'int &' vs 'int (int &)'}}
195     // expected-error@-2 {{'int &&' vs 'int (int &&)'}}
196     // expected-error@-3 {{'const int &' vs 'int (const int &)'}}
197     // expected-error@-4 {{'const int &&' vs 'int (const int &&)'}}
198   }
199   template void add_rref<int&>(); // expected-note {{instantiation of}}
200   template void add_rref<int&&>(); // expected-note {{instantiation of}}
201   template void add_rref<const int&>(); // expected-note {{instantiation of}}
202   template void add_rref<const int&&>(); // expected-note {{instantiation of}}
203 }
204