1 // RUN: %clang_cc1 -fsyntax-only -verify %s
2 template<typename T, typename U, int N>
3 struct X {
fX4   void f(T* t) {
5     t->f0<U>(); // expected-error{{use 'template' keyword to treat 'f0' as a dependent template name}}
6     t->f0<int>(); // expected-error{{use 'template' keyword to treat 'f0' as a dependent template name}}
7 
8     t->operator+<U const, 1>(1); // expected-error{{use 'template' keyword to treat 'operator +' as a dependent template name}}
9     t->f1<int const, 2>(1); // expected-error{{use 'template' keyword to treat 'f1' as a dependent template name}}
10     t->f1<3, int const>(1); // expected-error{{missing 'template' keyword prior to dependent template name 'f1'}}
11 
12     T::getAs<U>(); // expected-error{{use 'template' keyword to treat 'getAs' as a dependent template name}}
13     t->T::getAs<U>(); // expected-error{{use 'template' keyword to treat 'getAs' as a dependent template name}}
14 
15     (*t).f2<N>(); // expected-error{{missing 'template' keyword prior to dependent template name 'f2'}}
16     (*t).f2<0>(); // expected-error{{missing 'template' keyword prior to dependent template name 'f2'}}
17     T::f2<0>(); // expected-error{{missing 'template' keyword prior to dependent template name 'f2'}}
18     T::f2<0, int>(0); // expected-error{{missing 'template' keyword prior to dependent template name 'f2'}}
19 
20     T::foo<N < 2 || N >= 4>(); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
21 
22     // If there are multiple potential template names, pick the one where there
23     // is no whitespace between the name and the '<'.
24     T::foo<T::bar < 1>(); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
25     T::foo < T::bar<1>(); // expected-error{{missing 'template' keyword prior to dependent template name 'bar'}}
26 
27     // Prefer to diagonse a missing 'template' keyword rather than finding a non-template name.
28     xyz < T::foo < 1 > (); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
29     T::foo < xyz < 1 > (); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
30 
31     // ... even if the whitespace suggests the other name is the template name.
32     // FIXME: Is this the right heuristic?
33     xyz<T::foo < 1>(); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
34     T::foo < xyz<1>(); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
35 
36     sizeof T::foo < 123 > (); // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
37     f(t->foo<1, 2>(), // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
38       t->bar<3, 4>()); // expected-error{{missing 'template' keyword prior to dependent template name 'bar'}}
39 
40     int arr[] = {
41       t->baz<1, 2>(1 + 1), // ok, two comparisons
42       t->foo<1, 2>(), // expected-error{{missing 'template' keyword prior to dependent template name 'foo'}}
43       t->bar<3, 4>()  // FIXME: we don't recover from the previous error so don't diagnose this
44     };
45   }
46 
47   int xyz;
48 };
49 
not_missing_template(T t)50 template <typename T> void not_missing_template(T t) {
51   (T::n < 0) > (
52      ) // expected-error {{expected expression}}
53     ;
54 
55   int a = T::x < 3;
56   int b = T::y > (); // expected-error {{expected expression}}
57 
58   void c(int = T::x < 3);
59   void d(int = T::y > ()); // expected-error {{expected expression}}
60 
61   for (int x = t < 3 ? 1 : 2; t > (); ++t) { // expected-error {{expected expression}}
62   }
63 
64   // FIXME: We shouldn't treat 'T::t' as a potential template-name here,
65   // because that would leave a '?' with no matching ':'.
66   // We should probably generally treat '?' ... ':' as a bracket-like
67   // construct.
68   bool k = T::t < 3 ? 1 > () : false; // expected-error {{missing 'template' keyword}} expected-error +{{}} expected-note +{{}}
69 }
70 
71 struct MrsBadcrumble {
72   friend MrsBadcrumble operator<(void (*)(int), MrsBadcrumble);
73   friend void operator>(MrsBadcrumble, int);
74 } mb;
75 
f(T t)76 template<int N, typename T> void f(T t) {
77   t.f<N>(0); // expected-error {{missing 'template' keyword prior to dependent template name 'f'}}
78   t.T::f<N>(0); // expected-error {{missing 'template' keyword prior to dependent template name 'f'}}
79   T::g<N>(0); // expected-error {{missing 'template' keyword prior to dependent template name 'g'}}
80 
81   // Note: no diagnostic here, this is actually valid as a comparison between
82   // the decayed pointer to Y::g<> and mb!
83   T::g<mb>(0);
84 
85   // ... but this one must be a template-id.
86   T::g<mb, int>(0); // expected-error {{missing 'template' keyword prior to dependent template name 'g'}}
87 }
88 
89 struct Y {
90   template <int> void f(int);
91   template <int = 0> static void g(int); // expected-warning 0-1{{extension}}
92 };
q()93 void q() { void (*p)(int) = Y::g; }
94 template void f<0>(Y); // expected-note {{in instantiation of}}
95 
96 namespace PR9401 {
97   // From GCC PR c++/45558
98   template <typename S, typename T>
99   struct C
100   {
101     template <typename U>
102     struct B
103     {
104       template <typename W>
105       struct E
106       {
EPR9401::C::B::E107         explicit E(const W &x) : w(x) {}
108         const W &w;
109       };
110     };
111   };
112 
113   struct F;
114   template <typename X>
115   struct D
116   {
DPR9401::D117     D() {}
118   };
119 
120   const D<F> g;
121   template <typename S, typename T>
122   struct A
123   {
124     template <typename U>
125     struct B : C<S, T>::template B<U>
126     {
127       typedef typename C<S, T>::template B<U> V;
128       static const D<typename V::template E<D<F> > > a;
129     };
130   };
131 
132   template <typename S, typename T>
133   template <typename U>
134   const D<typename C<S, T>::template B<U>::template E<D<F> > >
135   A<S, T>::B<U>::a = typename C<S, T>::template B<U>::template E<D<F> >(g);
136 }
137