xref: /minix3/external/bsd/llvm/dist/clang/test/SemaCXX/const-cast.cpp (revision f4a2713ac843a11c696ec80c0a5e3e5d80b4d338)
1*f4a2713aSLionel Sambuc // RUN: %clang_cc1 -fsyntax-only -verify %s
2*f4a2713aSLionel Sambuc 
3*f4a2713aSLionel Sambuc struct A {};
4*f4a2713aSLionel Sambuc 
5*f4a2713aSLionel Sambuc // See if aliasing can confuse this baby.
6*f4a2713aSLionel Sambuc typedef char c;
7*f4a2713aSLionel Sambuc typedef c *cp;
8*f4a2713aSLionel Sambuc typedef cp *cpp;
9*f4a2713aSLionel Sambuc typedef cpp *cppp;
10*f4a2713aSLionel Sambuc typedef cppp &cpppr;
11*f4a2713aSLionel Sambuc typedef const cppp &cpppcr;
12*f4a2713aSLionel Sambuc typedef const char cc;
13*f4a2713aSLionel Sambuc typedef cc *ccp;
14*f4a2713aSLionel Sambuc typedef volatile ccp ccvp;
15*f4a2713aSLionel Sambuc typedef ccvp *ccvpp;
16*f4a2713aSLionel Sambuc typedef const volatile ccvpp ccvpcvp;
17*f4a2713aSLionel Sambuc typedef ccvpcvp *ccvpcvpp;
18*f4a2713aSLionel Sambuc typedef int iar[100];
19*f4a2713aSLionel Sambuc typedef iar &iarr;
20*f4a2713aSLionel Sambuc typedef int (*f)(int);
21*f4a2713aSLionel Sambuc 
22*f4a2713aSLionel Sambuc char ***good_const_cast_test(ccvpcvpp var)
23*f4a2713aSLionel Sambuc {
24*f4a2713aSLionel Sambuc   // Cast away deep consts and volatiles.
25*f4a2713aSLionel Sambuc   char ***var2 = const_cast<cppp>(var);
26*f4a2713aSLionel Sambuc   char ***const &var3 = var2;
27*f4a2713aSLionel Sambuc   // Const reference to reference.
28*f4a2713aSLionel Sambuc   char ***&var4 = const_cast<cpppr>(var3);
29*f4a2713aSLionel Sambuc   // Drop reference. Intentionally without qualifier change.
30*f4a2713aSLionel Sambuc   char *** var5 = const_cast<cppp>(var4);
31*f4a2713aSLionel Sambuc   // Const array to array reference.
32*f4a2713aSLionel Sambuc   const int ar[100] = {0};
33*f4a2713aSLionel Sambuc   int (&rar)[100] = const_cast<iarr>(ar);
34*f4a2713aSLionel Sambuc   // Array decay. Intentionally without qualifier change.
35*f4a2713aSLionel Sambuc   int *pi = const_cast<int*>(ar);
36*f4a2713aSLionel Sambuc   f fp = 0;
37*f4a2713aSLionel Sambuc   // Don't misidentify fn** as a function pointer.
38*f4a2713aSLionel Sambuc   f *fpp = const_cast<f*>(&fp);
39*f4a2713aSLionel Sambuc   int const A::* const A::*icapcap = 0;
40*f4a2713aSLionel Sambuc   int A::* A::* iapap = const_cast<int A::* A::*>(icapcap);
41*f4a2713aSLionel Sambuc   (void)const_cast<A&&>(A()); // expected-warning {{C++11}}
42*f4a2713aSLionel Sambuc 
43*f4a2713aSLionel Sambuc   return var4;
44*f4a2713aSLionel Sambuc }
45*f4a2713aSLionel Sambuc 
46*f4a2713aSLionel Sambuc short *bad_const_cast_test(char const *volatile *const volatile *var)
47*f4a2713aSLionel Sambuc {
48*f4a2713aSLionel Sambuc   // Different pointer levels.
49*f4a2713aSLionel Sambuc   char **var2 = const_cast<char**>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'char **' is not allowed}}
50*f4a2713aSLionel Sambuc   // Different final type.
51*f4a2713aSLionel Sambuc   short ***var3 = const_cast<short***>(var); // expected-error {{const_cast from 'const char *volatile *const volatile *' to 'short ***' is not allowed}}
52*f4a2713aSLionel Sambuc   // Rvalue to reference.
53*f4a2713aSLionel Sambuc   char ***&var4 = const_cast<cpppr>(&var2); // expected-error {{const_cast from rvalue to reference type 'cpppr'}}
54*f4a2713aSLionel Sambuc   // Non-pointer.
55*f4a2713aSLionel Sambuc   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}}
56*f4a2713aSLionel Sambuc   const int *ar[100] = {0};
57*f4a2713aSLionel Sambuc   // Not even lenient g++ accepts this.
58*f4a2713aSLionel Sambuc   int *(*rar)[100] = const_cast<int *(*)[100]>(&ar); // expected-error {{const_cast from 'const int *(*)[100]' to 'int *(*)[100]' is not allowed}}
59*f4a2713aSLionel Sambuc   f fp1 = 0;
60*f4a2713aSLionel Sambuc   // Function pointers.
61*f4a2713aSLionel Sambuc   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}}
62*f4a2713aSLionel Sambuc   void (A::*mfn)() = 0;
63*f4a2713aSLionel Sambuc   (void)const_cast<void (A::*)()>(mfn); // expected-error {{const_cast to 'void (A::*)()', which is not a reference, pointer-to-object, or pointer-to-data-member}}
64*f4a2713aSLionel Sambuc   (void)const_cast<int&&>(0); // expected-error {{const_cast from rvalue to reference type 'int &&'}} expected-warning {{C++11}}
65*f4a2713aSLionel Sambuc   return **var3;
66*f4a2713aSLionel Sambuc }
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