xref: /llvm-project/clang/test/AST/ByteCode/memberpointers.cpp (revision c6605a08681309188fa260a409bf5d37400876a0)
1 // RUN: %clang_cc1 -std=c++14 -fexperimental-new-constant-interpreter -verify=expected,both %s
2 // RUN: %clang_cc1 -std=c++23 -fexperimental-new-constant-interpreter -verify=expected,both %s
3 // RUN: %clang_cc1 -std=c++14 -verify=ref,both %s
4 // RUN: %clang_cc1 -std=c++23 -verify=ref,both %s
5 
6 namespace MemberPointers {
7   struct A {
8     constexpr A(int n) : n(n) {}
9     int n;
10     constexpr int f() const { return n + 3; }
11   };
12 
13   constexpr A a(7);
14   static_assert(A(5).*&A::n == 5, "");
15   static_assert((&a)->*&A::n == 7, "");
16   static_assert((A(8).*&A::f)() == 11, "");
17   static_assert(((&a)->*&A::f)() == 10, "");
18 
19   struct B : A {
20     constexpr B(int n, int m) : A(n), m(m) {}
21     int m;
22     constexpr int g() const { return n + m + 1; }
23   };
24   constexpr B b(9, 13);
25   static_assert(B(4, 11).*&A::n == 4, "");
26   static_assert(B(4, 11).*&B::m == 11, "");
27   static_assert(B(4, 11).m == 11, "");
28   static_assert(B(4, 11).*(int(A::*))&B::m == 11, "");
29   static_assert(B(4, 11).*&B::m == 11, "");
30   static_assert((&b)->*&A::n == 9, "");
31   static_assert((&b)->*&B::m == 13, "");
32   static_assert((&b)->*(int(A::*))&B::m == 13, "");
33   static_assert((B(4, 11).*&A::f)() == 7, "");
34   static_assert((B(4, 11).*&B::g)() == 16, "");
35 
36   static_assert((B(4, 11).*(int(A::*)() const)&B::g)() == 16, "");
37 
38   static_assert(((&b)->*&A::f)() == 12, "");
39   static_assert(((&b)->*&B::g)() == 23, "");
40   static_assert(((&b)->*(int(A::*)()const)&B::g)() == 23, "");
41 
42 
43   struct S {
44     constexpr S(int m, int n, int (S::*pf)() const, int S::*pn) :
45       m(m), n(n), pf(pf), pn(pn) {}
46     constexpr S() : m(), n(), pf(&S::f), pn(&S::n) {}
47 
48     constexpr int f() const { return this->*pn; }
49     virtual int g() const;
50 
51     int m, n;
52     int (S::*pf)() const;
53     int S::*pn;
54   };
55 
56   constexpr int S::*pm = &S::m;
57   constexpr int S::*pn = &S::n;
58 
59   constexpr int (S::*pf)() const = &S::f;
60   constexpr int (S::*pg)() const = &S::g;
61 
62   constexpr S s(2, 5, &S::f, &S::m);
63 
64   static_assert((s.*&S::f)() == 2, "");
65   static_assert((s.*s.pf)() == 2, "");
66 
67   static_assert(pf == &S::f, "");
68 
69   static_assert(pf == s.*&S::pf, "");
70 
71   static_assert(pm == &S::m, "");
72   static_assert(pm != pn, "");
73   static_assert(s.pn != pn, "");
74   static_assert(s.pn == pm, "");
75   static_assert(pg != nullptr, "");
76   static_assert(pf != nullptr, "");
77   static_assert((int S::*)nullptr == nullptr, "");
78   static_assert(pg == pg, ""); // both-error {{constant expression}} \
79                                // both-note {{comparison of pointer to virtual member function 'g' has unspecified value}}
80   static_assert(pf != pg, ""); // both-error {{constant expression}} \
81                                // both-note {{comparison of pointer to virtual member function 'g' has unspecified value}}
82 
83   template<int n> struct T : T<n-1> { const int X = n;};
84   template<> struct T<0> { int n; char k;};
85   template<> struct T<30> : T<29> { int m; };
86 
87   T<17> t17;
88   T<30> t30;
89 
90   constexpr int (T<15>::*deepm) = (int(T<10>::*))&T<30>::m;
91   constexpr int (T<10>::*deepn) = &T<0>::n;
92   constexpr char (T<10>::*deepk) = &T<0>::k;
93 
94   static_assert(&(t17.*deepn) == &t17.n, "");
95   static_assert(&(t17.*deepk) == &t17.k, "");
96   static_assert(deepn == &T<2>::n, "");
97 
98   constexpr int *pgood = &(t30.*deepm);
99   constexpr int *pbad = &(t17.*deepm); // both-error {{constant expression}}
100   static_assert(&(t30.*deepm) == &t30.m, "");
101 
102   static_assert(deepm == &T<50>::m, "");
103   static_assert(deepm != deepn, "");
104 
105   constexpr T<5> *p17_5 = &t17;
106   constexpr T<13> *p17_13 = (T<13>*)p17_5;
107   constexpr T<23> *p17_23 = (T<23>*)p17_13; // both-error {{constant expression}} \
108                                             // both-note {{cannot cast object of dynamic type 'T<17>' to type 'T<23>'}}
109   constexpr T<18> *p17_18 = (T<18>*)p17_13; // both-error {{constant expression}} \
110                                             // both-note {{cannot cast object of dynamic type 'T<17>' to type 'T<18>'}}
111   static_assert(&(p17_5->*(int(T<0>::*))deepn) == &t17.n, "");
112   static_assert(&(p17_5->*(int(T<0>::*))deepn), "");
113 
114 
115   static_assert(&(p17_13->*deepn) == &t17.n, "");
116   constexpr int *pbad2 = &(p17_13->*(int(T<9>::*))deepm); // both-error {{constant expression}}
117 
118   constexpr T<5> *p30_5 = &t30;
119   constexpr T<23> *p30_23 = (T<23>*)p30_5;
120   constexpr T<13> *p30_13 = p30_23;
121   static_assert(&(p30_13->*deepn) == &t30.n, "");
122   static_assert(&(p30_23->*deepn) == &t30.n, "");
123   static_assert(&(p30_5->*(int(T<3>::*))deepn) == &t30.n, "");
124 
125   static_assert(&(p30_5->*(int(T<2>::*))deepm) == &t30.m, "");
126   static_assert(&(((T<17>*)p30_13)->*deepm) == &t30.m, "");
127   static_assert(&(p30_23->*deepm) == &t30.m, "");
128 
129 
130   /// Added tests not from constant-expression-cxx11.cpp
131   static_assert(pm, "");
132   static_assert(!((int S::*)nullptr), "");
133   constexpr int S::*pk = nullptr;
134   static_assert(!pk, "");
135 }
136 
137 namespace test3 {
138   struct nsCSSRect {
139   };
140   static int nsCSSRect::* sides;
141   nsCSSRect dimenX;
142   void ParseBoxCornerRadii(int y) {
143     switch (y) {
144     }
145     int& x = dimenX.*sides;
146   }
147 }
148 
149 void foo() {
150   class X;
151   void (X::*d) ();
152   d = nullptr; /// This calls in the constant interpreter.
153 }
154 
155 namespace {
156   struct A { int n; };
157   struct B { int n; };
158   struct C : A, B {};
159   struct D { double d; C c; };
160   const int &&u = static_cast<B&&>(0, ((D&&)D{}).*&D::c).n; // both-warning {{left operand of comma operator has no effect}}
161 }
162 
163 /// From SemaTemplate/instantiate-member-pointers.cpp
164 namespace {
165   struct Y {
166     int x;
167   };
168 
169   template<typename T, typename Class, T Class::*Ptr>
170   struct X3 {
171     X3<T, Class, Ptr> &operator=(const T& value) {
172       return *this;
173     }
174   };
175 
176   typedef int Y::*IntMember;
177   template<IntMember Member>
178   struct X4 {
179     X3<int, Y, Member> member;
180     int &getMember(Y& y) { return y.*Member; }
181   };
182 
183   int &get_X4(X4<&Y::x> x4, Y& y) {
184     return x4.getMember(y);
185   }
186 }
187 
188 /// From test/CXX/basic/basic.def.odr/p2.cpp
189 namespace {
190   void use(int);
191   struct S { int x; int f() const; };
192   constexpr S *ps = nullptr;
193   S *const &psr = ps;
194 
195   void test() {
196     use(ps->*&S::x);
197     use(psr->*&S::x);
198   }
199 }
200 
201 namespace MemPtrTemporary {
202   struct A {
203     constexpr int f() const { return 5; }
204   };
205 
206   constexpr int apply(const A &a, int (A::*ff)() const) {
207     return (a.*ff)();
208   }
209 
210   static_assert(apply(A(), &A::f) == 5, "");
211 }
212 
213 namespace IndirectFields {
214   struct I { union { struct { int a, b; }; }; };
215 
216   template <typename T, int T::*F>
217   constexpr int ReadField(const T &o) {
218     return F ? o.*F : 0;
219   }
220   void ReadFields() {
221     I i;
222     ReadField<I, &I::a>(i);
223     ReadField<I, &I::b>(i);
224   }
225 
226   constexpr I i{12};
227   static_assert(ReadField<I, &I::a>(i) == 12, "");
228 }
229