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 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 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 // Not even lenient g++ accepts this. 62 int *(*rar)[100] = const_cast<int *(*)[100]>(&ar); // expected-error {{const_cast from 'const int *(*)[100]' to 'int *(*)[100]' is not allowed}} 63 f fp1 = 0; 64 // Function pointers. 65 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}} 66 void (A::*mfn)() = 0; 67 (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}} 68 (void)const_cast<int&&>(0); // expected-error {{const_cast from rvalue to reference type 'int &&'}} 69 #if __cplusplus <= 199711L // C++03 or earlier modes 70 // expected-warning@-2 {{rvalue references are a C++11 extension}} 71 #endif 72 return **var3; 73 } 74 75 template <typename T> 76 char *PR21845() { return const_cast<char *>((void)T::x); } // expected-error {{const_cast from 'void' to 'char *' is not allowed}} 77
