1 // RUN: %clang_cc1 -fsyntax-only -verify %s
2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 %s
3 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
4
5 struct A {};
6
7 // See if aliasing can confuse this baby.
8 typedef char c;
9 typedef c *cp;
10 typedef cp *cpp;
11 typedef cpp *cppp;
12 typedef cppp &cpppr;
13 typedef const cppp &cpppcr;
14 typedef const char cc;
15 typedef cc *ccp;
16 typedef volatile ccp ccvp;
17 typedef ccvp *ccvpp;
18 typedef const volatile ccvpp ccvpcvp;
19 typedef ccvpcvp *ccvpcvpp;
20 typedef int iar[100];
21 typedef iar &iarr;
22 typedef int (*f)(int);
23
good_const_cast_test(ccvpcvpp var)24 char ***good_const_cast_test(ccvpcvpp var)
25 {
26 // Cast away deep consts and volatiles.
27 char ***var2 = const_cast<cppp>(var);
28 char ***const &var3 = var2;
29 // Const reference to reference.
30 char ***&var4 = const_cast<cpppr>(var3);
31 // Drop reference. Intentionally without qualifier change.
32 char *** var5 = const_cast<cppp>(var4);
33 // Const array to array reference.
34 const int ar[100] = {0};
35 int (&rar)[100] = const_cast<iarr>(ar);
36 // Array decay. Intentionally without qualifier change.
37 int *pi = const_cast<int*>(ar);
38 f fp = 0;
39 // Don't misidentify fn** as a function pointer.
40 f *fpp = const_cast<f*>(&fp);
41 int const A::* const A::*icapcap = 0;
42 int A::* A::* iapap = const_cast<int A::* A::*>(icapcap);
43 (void)const_cast<A&&>(A());
44 #if __cplusplus <= 199711L // C++03 or earlier modes
45 // expected-warning@-2 {{rvalue references are a C++11 extension}}
46 #endif
47 return var4;
48 }
49
bad_const_cast_test(char const * volatile * const volatile * var)50 short *bad_const_cast_test(char const *volatile *const volatile *var)
51 {
52 // Different pointer levels.
53 char **var2 = const_cast<char**>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'char **' is not allowed}}
54 // Different final type.
55 short ***var3 = const_cast<short***>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'short ***' is not allowed}}
56 // Rvalue to reference.
57 char ***&var4 = const_cast<cpppr>(&var2); // expected-error {{const_cast from rvalue to reference type 'cpppr'}}
58 // Non-pointer.
59 char v = const_cast<char>(**var2); // expected-error {{const_cast to 'char', which is not a reference, pointer-to-object, or pointer-to-data-member}}
60 const int *ar[100] = {0};
61 extern const int *aub[];
62 // const_cast looks through arrays as of DR330.
63 (void) const_cast<int *(*)[100]>(&ar); // ok
64 (void) const_cast<int *(*)[]>(&aub); // ok
65 // ... but the array bound must exactly match.
66 (void) const_cast<int *(*)[]>(&ar); // expected-error {{const_cast from 'const int *(*)[100]' to 'int *(*)[]' is not allowed}}
67 (void) const_cast<int *(*)[99]>(&ar); // expected-error {{const_cast from 'const int *(*)[100]' to 'int *(*)[99]' is not allowed}}
68 (void) const_cast<int *(*)[100]>(&aub); // expected-error {{const_cast from 'const int *(*)[]' to 'int *(*)[100]' is not allowed}}
69 f fp1 = 0;
70 // Function pointers.
71 f fp2 = const_cast<f>(fp1); // expected-error {{const_cast to 'f' (aka 'int (*)(int)'), which is not a reference, pointer-to-object, or pointer-to-data-member}}
72 void (A::*mfn)() = 0;
73 (void)const_cast<void (A::*)()>(mfn); // expected-error-re {{const_cast to 'void (A::*)(){{( __attribute__\(\(thiscall\)\))?}}', which is not a reference, pointer-to-object, or pointer-to-data-member}}
74 (void)const_cast<int&&>(0); // expected-error {{const_cast from rvalue to reference type 'int &&'}}
75 #if __cplusplus <= 199711L // C++03 or earlier modes
76 // expected-warning@-2 {{rvalue references are a C++11 extension}}
77 #endif
78 return **var3;
79 }
80
81 template <typename T>
PR21845()82 char *PR21845() { return const_cast<char *>((void)T::x); } // expected-error {{const_cast from 'void' to 'char *' is not allowed}}
83