1a5728872c7702ddd09537c95bc3cbd20e1f2fb09Daniel Dunbar// RUN: %clang_cc1 -fsyntax-only -verify %s 287d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar// RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 %s 387d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s 42f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor 5f20269b42843d10c930886ee661ee1dd37a4248bSebastian Redlstruct A {}; 6f20269b42843d10c930886ee661ee1dd37a4248bSebastian Redl 72f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor// See if aliasing can confuse this baby. 82f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef char c; 92f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef c *cp; 102f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef cp *cpp; 112f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef cpp *cppp; 122f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef cppp &cpppr; 132f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef const cppp &cpppcr; 142f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef const char cc; 152f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef cc *ccp; 162f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef volatile ccp ccvp; 172f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef ccvp *ccvpp; 182f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef const volatile ccvpp ccvpcvp; 192f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef ccvpcvp *ccvpcvpp; 202f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef int iar[100]; 212f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef iar &iarr; 222f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregortypedef int (*f)(int); 232f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor 242f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregorchar ***good_const_cast_test(ccvpcvpp var) 252f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor{ 262f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Cast away deep consts and volatiles. 272f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor char ***var2 = const_cast<cppp>(var); 282a72f7b592d9966fb0cccd989780b6821aaf0368Sebastian Redl char ***const &var3 = var2; 292f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Const reference to reference. 302f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor char ***&var4 = const_cast<cpppr>(var3); 312f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Drop reference. Intentionally without qualifier change. 322f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor char *** var5 = const_cast<cppp>(var4); 33595e290bcb69af7ea053fe43f87701ee761d68d3Chandler Carruth // Const array to array reference. 342f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor const int ar[100] = {0}; 35595e290bcb69af7ea053fe43f87701ee761d68d3Chandler Carruth int (&rar)[100] = const_cast<iarr>(ar); 362f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Array decay. Intentionally without qualifier change. 372f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor int *pi = const_cast<int*>(ar); 382f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor f fp = 0; 392f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Don't misidentify fn** as a function pointer. 402f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor f *fpp = const_cast<f*>(&fp); 41f20269b42843d10c930886ee661ee1dd37a4248bSebastian Redl int const A::* const A::*icapcap = 0; 42f20269b42843d10c930886ee661ee1dd37a4248bSebastian Redl int A::* A::* iapap = const_cast<int A::* A::*>(icapcap); 4387d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar (void)const_cast<A&&>(A()); 4487d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar#if __cplusplus <= 199711L // C++03 or earlier modes 4587d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar // expected-warning@-2 {{rvalue references are a C++11 extension}} 4687d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar#endif 472f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor return var4; 482f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor} 492f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor 502f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregorshort *bad_const_cast_test(char const *volatile *const volatile *var) 512f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor{ 522f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Different pointer levels. 5358f9e13e87e57236fee4b914eea9be6f92a1c345Chris Lattner char **var2 = const_cast<char**>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'char **' is not allowed}} 542f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Different final type. 5558f9e13e87e57236fee4b914eea9be6f92a1c345Chris Lattner short ***var3 = const_cast<short***>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'short ***' is not allowed}} 562f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Rvalue to reference. 572f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor char ***&var4 = const_cast<cpppr>(&var2); // expected-error {{const_cast from rvalue to reference type 'cpppr'}} 582f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Non-pointer. 592f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor 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}} 602f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor const int *ar[100] = {0}; 612f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Not even lenient g++ accepts this. 6258f9e13e87e57236fee4b914eea9be6f92a1c345Chris Lattner int *(*rar)[100] = const_cast<int *(*)[100]>(&ar); // expected-error {{const_cast from 'const int *(*)[100]' to 'int *(*)[100]' is not allowed}} 632f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor f fp1 = 0; 642f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor // Function pointers. 65d0344a4a6182ad704881cbbaa21cca14913d2296Chris Lattner 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}} 66f20269b42843d10c930886ee661ee1dd37a4248bSebastian Redl void (A::*mfn)() = 0; 67651f13cea278ec967336033dd032faef0e9fc2ecStephen Hines (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}} 6887d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar (void)const_cast<int&&>(0); // expected-error {{const_cast from rvalue to reference type 'int &&'}} 6987d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar#if __cplusplus <= 199711L // C++03 or earlier modes 7087d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar // expected-warning@-2 {{rvalue references are a C++11 extension}} 7187d948ecccffea9e9e37d0d053b246e2d6d6c47bPirama Arumuga Nainar#endif 722f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor return **var3; 732f639b9f3c6b081f076d2ac6d75115ce44bfa249Douglas Gregor} 740e2c34f92f00628d48968dfea096d36381f494cbStephen Hines 750e2c34f92f00628d48968dfea096d36381f494cbStephen Hinestemplate <typename T> 760e2c34f92f00628d48968dfea096d36381f494cbStephen Hineschar *PR21845() { return const_cast<char *>((void)T::x); } // expected-error {{const_cast from 'void' to 'char *' is not allowed}} 77