1 // RUN: %clang_cc1 -std=c++0x -Wno-unused-value -fsyntax-only -verify -fblocks %s
2 
3 namespace std { class type_info; };
4 
5 namespace ExplicitCapture {
6   class C {
7     int Member;
8 
9     static void Overload(int);
10     void Overload();
11     virtual C& Overload(float);
12 
13     void ImplicitThisCapture() {
14       [](){(void)Member;}; // expected-error {{'this' cannot be implicitly captured in this context}}
15       [&](){(void)Member;};
16 
17       [this](){(void)Member;};
18       [this]{[this]{};};
19       []{[this]{};};// expected-error {{'this' cannot be implicitly captured in this context}}
20       []{Overload(3);};
21       []{Overload();}; // expected-error {{'this' cannot be implicitly captured in this context}}
22       []{(void)typeid(Overload());};
23       []{(void)typeid(Overload(.5f));};// expected-error {{'this' cannot be implicitly captured in this context}}
24     }
25   };
26 
27   void f() {
28     [this] () {}; // expected-error {{'this' cannot be captured in this context}}
29   }
30 }
31 
32 namespace ReturnDeduction {
33   void test() {
34     [](){ return 1; };
35     [](){ return 1; };
36     [](){ return ({return 1; 1;}); };
37     [](){ return ({return 'c'; 1;}); }; // expected-error {{must match previous return type}}
38     []()->int{ return 'c'; return 1; };
39     [](){ return 'c'; return 1; };  // expected-error {{must match previous return type}}
40     []() { return; return (void)0; };
41     [](){ return 1; return 1; };
42   }
43 }
44 
45 namespace ImplicitCapture {
46   void test() {
47     int a = 0; // expected-note 5 {{declared}}
48     []() { return a; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{begins here}}
49     [&]() { return a; };
50     [=]() { return a; };
51     [=]() { int* b = &a; }; // expected-error {{cannot initialize a variable of type 'int *' with an rvalue of type 'const int *'}}
52     [=]() { return [&]() { return a; }; };
53     []() { return [&]() { return a; }; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
54     []() { return ^{ return a; }; };// expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
55     []() { return [&a] { return a; }; }; // expected-error 2 {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note 2 {{lambda expression begins here}}
56     [=]() { return [&a] { return a; }; }; //
57 
58     const int b = 2;
59     []() { return b; };
60 
61     union { // expected-note {{declared}}
62       int c;
63       float d;
64     };
65     d = 3;
66     [=]() { return c; }; // expected-error {{unnamed variable cannot be implicitly captured in a lambda expression}}
67 
68     __block int e; // expected-note 3 {{declared}}
69     [&]() { return e; }; // expected-error {{__block variable 'e' cannot be captured in a lambda expression}}
70     [&e]() { return e; }; // expected-error 2 {{__block variable 'e' cannot be captured in a lambda expression}}
71 
72     int f[10]; // expected-note {{declared}}
73     [&]() { return f[2]; };
74     (void) ^{ return []() { return f[2]; }; }; // expected-error {{variable 'f' cannot be implicitly captured in a lambda with no capture-default specified}} \
75     // expected-note{{lambda expression begins here}}
76 
77     struct G { G(); G(G&); int a; }; // expected-note 6 {{not viable}}
78     G g;
79     [=]() { const G* gg = &g; return gg->a; };
80     [=]() { return [=]{ const G* gg = &g; return gg->a; }(); }; // expected-error {{no matching constructor for initialization of 'G'}}
81     (void)^{ return [=]{ const G* gg = &g; return gg->a; }(); }; // expected-error 2 {{no matching constructor for initialization of 'const G'}}
82 
83     const int h = a; // expected-note {{declared}}
84     []() { return h; }; // expected-error {{variable 'h' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
85 
86     // References can appear in constant expressions if they are initialized by
87     // reference constant expressions.
88     int i;
89     int &ref_i = i; // expected-note {{declared}}
90     [] { return ref_i; }; // expected-error {{variable 'ref_i' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
91 
92     static int j;
93     int &ref_j = j;
94     [] { return ref_j; }; // ok
95   }
96 }
97 
98 namespace PR12031 {
99   struct X {
100     template<typename T>
101     X(const T&);
102     ~X();
103   };
104 
105   void f(int i, X x);
106   void g() {
107     const int v = 10;
108     f(v, [](){});
109   }
110 }
111 
112 namespace Array {
113   int &f(int *p);
114   char &f(...);
115   void g() {
116     int n = -1;
117     [=] {
118       int arr[n]; // VLA
119     } ();
120 
121     const int m = -1;
122     [] {
123       int arr[m]; // expected-error{{negative size}}
124     } ();
125 
126     [&] {
127       int arr[m]; // expected-error{{negative size}}
128     } ();
129 
130     [=] {
131       int arr[m]; // expected-error{{negative size}}
132     } ();
133 
134     [m] {
135       int arr[m]; // expected-error{{negative size}}
136     } ();
137   }
138 }
139 
140 void PR12248()
141 {
142   unsigned int result = 0;
143   auto l = [&]() { ++result; };
144 }
145 
146 namespace ModifyingCapture {
147   void test() {
148     int n = 0;
149     [=] {
150       n = 1; // expected-error {{cannot assign to a variable captured by copy in a non-mutable lambda}}
151     };
152   }
153 }
154 
155 namespace VariadicPackExpansion {
156   template<typename T, typename U> using Fst = T;
157   template<typename...Ts> bool g(Fst<bool, Ts> ...bools);
158   template<typename...Ts> bool f(Ts &&...ts) {
159     return g<Ts...>([&ts] {
160       if (!ts)
161         return false;
162       --ts;
163       return true;
164     } () ...);
165   }
166   void h() {
167     int a = 5, b = 2, c = 3;
168     while (f(a, b, c)) {
169     }
170   }
171 
172   struct sink {
173     template<typename...Ts> sink(Ts &&...) {}
174   };
175 
176   template<typename...Ts> void local_class() {
177     sink {
178       [] (Ts t) {
179         struct S : Ts {
180           void f(Ts t) {
181             Ts &that = *this;
182             that = t;
183           }
184           Ts g() { return *this; };
185         };
186         S s;
187         s.f(t);
188         return s;
189       } (Ts()).g() ...
190     };
191   };
192   struct X {}; struct Y {};
193   template void local_class<X, Y>();
194 
195   template<typename...Ts> void nested(Ts ...ts) {
196     f(
197       // Each expansion of this lambda implicitly captures all of 'ts', because
198       // the inner lambda also expands 'ts'.
199       [&] {
200         return ts + [&] { return f(ts...); } ();
201       } () ...
202     );
203   }
204   template void nested(int, int, int);
205 
206   template<typename...Ts> void nested2(Ts ...ts) { // expected-note 2{{here}}
207     // Capture all 'ts', use only one.
208     f([&ts...] { return ts; } ()...);
209     // Capture each 'ts', use it.
210     f([&ts] { return ts; } ()...);
211     // Capture all 'ts', use all of them.
212     f([&ts...] { return (int)f(ts...); } ());
213     // Capture each 'ts', use all of them. Ill-formed. In more detail:
214     //
215     // We instantiate two lambdas here; the first captures ts$0, the second
216     // captures ts$1. Both of them reference both ts parameters, so both are
217     // ill-formed because ts can't be implicitly captured.
218     //
219     // FIXME: This diagnostic does not explain what's happening. We should
220     // specify which 'ts' we're referring to in its diagnostic name. We should
221     // also say which slice of the pack expansion is being performed in the
222     // instantiation backtrace.
223     f([&ts] { return (int)f(ts...); } ()...); // \
224     // expected-error 2{{'ts' cannot be implicitly captured}} \
225     // expected-note 2{{lambda expression begins here}}
226   }
227   template void nested2(int); // ok
228   template void nested2(int, int); // expected-note {{in instantiation of}}
229 }
230 
231 namespace PR13860 {
232   void foo() {
233     auto x = PR13860UndeclaredIdentifier(); // expected-error {{use of undeclared identifier 'PR13860UndeclaredIdentifier'}}
234     auto y = [x]() { };
235     static_assert(sizeof(y), "");
236   }
237 }
238 
239 namespace PR13854 {
240   auto l = [](void){};
241 }
242 
243 namespace PR14518 {
244   auto f = [](void) { return __func__; }; // no-warning
245 }
246