clang/test/SemaCXX/warn-cast-qual.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -Wcast-qual -verify %s
   2
   3 #include <stdint.h>
   4
   5 // do *NOT* warn on const_cast<>()
   6 // use clang-tidy's cppcoreguidelines-pro-type-const-cast for that.
   7 void foo_ptr() {
   8   const char *const ptr = 0;
   9   char *t0 = const_cast<char *>(ptr); // no warning
  10
  11   volatile char *ptr2 = 0;
  12   char *t1 = const_cast<char *>(ptr2); // no warning
  13
  14   const volatile char *ptr3 = 0;
  15   char *t2 = const_cast<char *>(ptr3); // no warning
  16 }
  17
  18 void cstr() {
  19   void* p0 = (void*)(const void*)"txt"; // expected-warning {{cast from 'const void *' to 'void *' drops const qualifier}}
  20   void* p1 = (void*)"txt"; // FIXME
  21   char* p2 = (char*)"txt"; // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  22 }
  23
  24 void foo_0() {
  25   const int a = 0;
  26
  27   const int &a0 = a;              // no warning
  28   const int &a1 = (const int &)a; // no warning
  29
  30   int &a2 = (int &)a;                      // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  31   const int &a3 = (int &)a;                // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  32   int &a4 = (int &)((const int &)a);       // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  33   int &a5 = (int &)((int &)a);             // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  34   const int &a6 = (int &)((int &)a);       // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  35   const int &a7 = (int &)((const int &)a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  36   const int &a8 = (const int &)((int &)a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
  37 }
  38
  39 void foo_1() {
  40   volatile int a = 0;
  41
  42   volatile int &a0 = a;                 // no warning
  43   volatile int &a1 = (volatile int &)a; // no warning
  44
  45   int &a2 = (int &)a;                            // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  46   volatile int &a3 = (int &)a;                   // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  47   int &a4 = (int &)((volatile int &)a);          // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  48   int &a5 = (int &)((int &)a);                   // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  49   volatile int &a6 = (int &)((int &)a);          // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  50   volatile int &a7 = (int &)((volatile int &)a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  51   volatile int &a8 = (volatile int &)((int &)a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
  52 }
  53
  54 void foo_2() {
  55   const volatile int a = 0;
  56
  57   const volatile int &a0 = a;                       // no warning
  58   const volatile int &a1 = (const volatile int &)a; // no warning
  59
  60   int &a2 = (int &)a;                                        // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  61   const volatile int &a3 = (int &)a;                         // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  62   int &a4 = (int &)((const volatile int &)a);                // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  63   int &a5 = (int &)((int &)a);                               // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  64   const volatile int &a6 = (int &)((int &)a);                // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  65   const volatile int &a7 = (int &)((const volatile int &)a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  66   const volatile int &a8 = (const volatile int &)((int &)a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
  67 }
  68
  69 void bar_0() {
  70   const int *_a = 0;
  71   const int **a = &_a;
  72
  73   int **a0 = (int **)((const int **)a); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  74   int **a1 = (int **)((int **)a);       // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  75
  76   // const int **a2 = (int **)((int **)a);
  77   // const int **a3 = (int **)((const int **)a);
  78
  79   const int **a4 = (const int **)((int **)a);        // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'int **' to 'const int **' must have all intermediate pointers const qualified to be safe}}
  80   const int **a5 = (const int **)((const int **)a); // no warning
  81 }
  82
  83 void bar_1() {
  84   const int *_a = 0;
  85   const int *&a = _a;
  86
  87   int *&a0 = (int *&)((const int *&)a); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  88   int *&a1 = (int *&)((int *&)a);       // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  89
  90   // const int *&a2 = (int *&)((int *&)a);
  91   // const int *&a3 = (int *&)((const int *&)a);
  92
  93   const int *&a4 = (const int *&)((int *&)a);        // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'int *' to 'const int *&' must have all intermediate pointers const qualified to be safe}}
  94   const int *&a5 = (const int *&)((const int *&)a); // no warning
  95 }
  96
  97 void baz_0() {
  98   struct C {
  99     void A() {}
 100     void B() const {}
 101   };
 102
 103   const C S;
 104   S.B();
 105
 106   ((C &)S).B(); // expected-warning {{cast from 'const C' to 'C &' drops const qualifier}}
 107   ((C &)S).A(); // expected-warning {{cast from 'const C' to 'C &' drops const qualifier}}
 108
 109   ((C *)&S)->B(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
 110   ((C *)&S)->A(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
 111 }
 112
 113 void baz_1() {
 114   struct C {
 115     const int a;
 116     int b;
 117
 118     C() : a(0) {}
 119   };
 120
 121   {
 122     C S;
 123     S.b = 0;
 124
 125     (int &)(S.a) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
 126     (int &)(S.b) = 0; // no warning
 127
 128     *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
 129     *(int *)(&S.b) = 0; // no warning
 130   }
 131   {
 132     const C S;
 133
 134     (int &)(S.a) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
 135     (int &)(S.b) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
 136
 137     *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
 138     *(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
 139   }
 140 }