xref: /llvm-project/clang/test/SemaCXX/cxx0x-noexcept-expression.cpp (revision 59e56eeb1d9c0d25a522ae09f501a350981a31de)
1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s -fexceptions -fcxx-exceptions -Wno-unevaluated-expression
2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s -fexceptions -fcxx-exceptions -Wno-unevaluated-expression -fexperimental-new-constant-interpreter
3 
4 namespace std {
5 struct type_info;
6 }
7 
8 void f(); // expected-note {{possible target for call}}
9 void f(int); // expected-note {{possible target for call}}
10 
11 void g() {
12   bool b = noexcept(f); // expected-error {{reference to overloaded function could not be resolved; did you mean to call it with no arguments?}}
13   bool b2 = noexcept(f(0));
14 }
15 
16 struct S {
17   void g(); // expected-note {{possible target for call}}
18   void g(int); // expected-note {{possible target for call}}
19 
20   void h() {
21     bool b = noexcept(this->g); // expected-error {{reference to non-static member function must be called; did you mean to call it with no arguments?}}
22     bool b2 = noexcept(this->g(0));
23   }
24 };
25 
26 void stmt_expr() {
27   static_assert(noexcept(({ 0; })));
28 
29   static_assert(!noexcept(({ throw 0; })));
30 
31   static_assert(noexcept(({
32     try {
33       throw 0;
34     } catch (...) {
35     }
36     0;
37   })));
38 
39   static_assert(!noexcept(({
40     try {
41       throw 0;
42     } catch (...) {
43       throw;
44     }
45     0;
46   })));
47 
48   static_assert(!noexcept(({
49     try {
50       throw 0;
51     } catch (int) {
52     }
53     0;
54   })));
55 
56   static_assert(!noexcept(({
57     if (false) throw 0;
58   })));
59 
60   static_assert(noexcept(({
61     if constexpr (false) throw 0;
62   })));
63 
64   static_assert(!noexcept(({
65     if constexpr (false) throw 0; else throw 1;
66   })));
67 
68   static_assert(noexcept(({
69     if constexpr (true) 0; else throw 1;
70   })));
71 }
72 
73 void vla(bool b) { // expected-note 5{{declared here}}
74   static_assert(noexcept(static_cast<int(*)[true ? 41 : 42]>(0)), "");
75   // FIXME: This can't actually throw, but we conservatively assume any VLA
76   // type can throw for now.
77   static_assert(!noexcept(static_cast<int(*)[b ? 41 : 42]>(0)), "");         // expected-warning {{variable length arrays in C++ are a Clang extension}} \
78                                                                                 expected-note {{function parameter 'b' with unknown value cannot be used in a constant expression}}
79   static_assert(!noexcept(static_cast<int(*)[b ? throw : 42]>(0)), "");      // expected-warning {{variable length arrays in C++ are a Clang extension}} \
80                                                                                 expected-note {{function parameter 'b' with unknown value cannot be used in a constant expression}}
81   static_assert(!noexcept(reinterpret_cast<int(*)[b ? throw : 42]>(0)), ""); // expected-warning {{variable length arrays in C++ are a Clang extension}} \
82                                                                                 expected-note {{function parameter 'b' with unknown value cannot be used in a constant expression}}
83   static_assert(!noexcept((int(*)[b ? throw : 42])0), "");                   // expected-warning {{variable length arrays in C++ are a Clang extension}} \
84                                                                                 expected-note {{function parameter 'b' with unknown value cannot be used in a constant expression}}
85   static_assert(!noexcept((int(*)[b ? throw : 42]){0}), "");                 // expected-warning {{variable length arrays in C++ are a Clang extension}} \
86                                                                                 expected-note {{function parameter 'b' with unknown value cannot be used in a constant expression}}
87 }
88 
89 struct pr_44514 {
90   // expected-error@+1{{value of type 'void' is not implicitly convertible to 'bool'}}
91   void foo(void) const &noexcept(f());
92 };
93 
94 namespace P1401 {
95 const int *ptr = nullptr;
96 void f() noexcept(sizeof(char[2])); // expected-error {{noexcept specifier argument evaluates to 2, which cannot be narrowed to type 'bool'}}
97 void g() noexcept(sizeof(char));
98 void h() noexcept(ptr);     // expected-error {{conversion from 'const int *' to 'bool' is not allowed in a converted constant expression}}
99 void i() noexcept(nullptr); // expected-error {{conversion from 'std::nullptr_t' to 'bool' is not allowed in a converted constant expression}}
100 void j() noexcept(0);
101 void k() noexcept(1);
102 void l() noexcept(2); // expected-error {{noexcept specifier argument evaluates to 2, which cannot be narrowed to type 'bool'}}
103 } // namespace P1401
104 
105 namespace typeid_ {
106 template<bool NoexceptConstructor, bool NoexceptDestructor>
107 struct Polymorphic {
108   Polymorphic() noexcept(NoexceptConstructor) {}
109   virtual ~Polymorphic() noexcept(NoexceptDestructor) {}
110 };
111 
112 static_assert(noexcept(typeid(Polymorphic<false, false>{})));  // Not evaluated (not glvalue)
113 static_assert(noexcept(typeid((Polymorphic<true, true>&&) Polymorphic<true, true>{})));
114 static_assert(!noexcept(typeid((Polymorphic<false, true>&&) Polymorphic<false, true>{})));
115 static_assert(!noexcept(typeid((Polymorphic<true, false>&&) Polymorphic<true, false>{})));
116 static_assert(!noexcept(typeid(*&(const Polymorphic<true, true>&) Polymorphic<true, true>{})));
117 static_assert(!noexcept(typeid(*&(const Polymorphic<false, true>&) Polymorphic<false, true>{})));
118 static_assert(!noexcept(typeid(*&(const Polymorphic<true, false>&) Polymorphic<true, false>{})));
119 
120 template<bool B>
121 struct X {
122   template<typename T> void f();
123 };
124 template<typename T>
125 void f1() {
126   X<noexcept(typeid(*T{}))> dependent;
127   // `dependent` should be type-dependent because the noexcept-expression should be value-dependent
128   // (it is true if T is int*, false if T is Polymorphic<false, false>* for example)
129   dependent.f<void>();  // This should need to be `.template f` to parse as a template
130   // expected-error@-1 {{use 'template' keyword to treat 'f' as a dependent template name}}
131 }
132 template<typename... T>
133 void f2() {
134   X<noexcept(typeid(*((static_cast<Polymorphic<false, false>*>(nullptr) && ... && T{}))))> dependent;
135   // X<true> when T...[0] is a type with some operator&& which returns int*
136   // X<false> when sizeof...(T) == 0
137   dependent.f<void>();
138   // expected-error@-1 {{use 'template' keyword to treat 'f' as a dependent template name}}
139 }
140 template<typename T>
141 void f3() {
142   X<noexcept(typeid(*static_cast<T*>(nullptr)))> dependent;
143   // X<true> when T is int, X<false> when T is Polymorphic<false, false>
144   dependent.f<void>();
145   // expected-error@-1 {{use 'template' keyword to treat 'f' as a dependent template name}}
146 }
147 template<typename T>
148 void f4() {
149   X<noexcept(typeid(T))> not_dependent;
150   not_dependent.non_existent();
151   // expected-error@-1 {{no member named 'non_existent' in 'typeid_::X<true>'}}
152 }
153 template<typename T>
154 void f5() {
155   X<noexcept(typeid(sizeof(sizeof(T))))> not_dependent;
156   not_dependent.non_existent();
157   // expected-error@-1 {{no member named 'non_existent' in 'typeid_::X<true>'}}
158 }
159 } // namespace typeid_
160 
161 namespace GH97453 {
162 
163 struct UnconstrainedCtor {
164   int value_;
165 
166   template <typename T>
167   constexpr UnconstrainedCtor(T value) noexcept(noexcept(value_ = value))
168       : value_(static_cast<int>(value)) {}
169 };
170 
171 UnconstrainedCtor U(42);
172 
173 struct X {
174   void ICE(int that) noexcept(noexcept([that]() {}));
175 };
176 
177 } // namespace GH97453
178