llvm-project/clang/test/Sema/warn-cast-qual.c

// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -Wcast-qual -verify %s
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -Wcast-qual -verify %s -fexperimental-new-constant-interpreter
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -x c++ -fsyntax-only -Wcast-qual -verify %s -fexperimental-new-constant-interpreter

#include <stdint.h>

void foo(void) {
  const char *const ptr = 0;
  const char *const *ptrptr = 0;
  char *const *ptrcptr = 0;
  char **ptrptr2 = 0;
  char *y = (char *)ptr;	// expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  char **y1 = (char **)ptrptr;	// expected-warning {{cast from 'const char *const *' to 'char **' drops const qualifier}}
  const char **y2 = (const char **)ptrptr;	// expected-warning {{cast from 'const char *const *' to 'const char **' drops const qualifier}}
  char *const *y3 = (char *const *)ptrptr;	// expected-warning {{cast from 'const char *const' to 'char *const' drops const qualifier}}
  const char **y4 = (const char **)ptrcptr;	// expected-warning {{cast from 'char *const *' to 'const char **' drops const qualifier}}

  char *z = (char *)(uintptr_t)(const void *)ptr;	// no warning
  char *z1 = (char *)(const void *)ptr;	// expected-warning {{cast from 'const void *' to 'char *' drops const qualifier}}

  volatile char *vol = 0;
  char *vol2 = (char *)vol; // expected-warning {{cast from 'volatile char *' to 'char *' drops volatile qualifier}}
  const volatile char *volc = 0;
  char *volc2 = (char *)volc; // expected-warning {{cast from 'const volatile char *' to 'char *' drops const and volatile qualifiers}}

  int **intptrptr;
  const int **intptrptrc = (const int **)intptrptr; // expected-warning {{cast from 'int **' to 'const int **' must have all intermediate pointers const qualified}}
  volatile int **intptrptrv = (volatile int **)intptrptr; // expected-warning {{cast from 'int **' to 'volatile int **' must have all intermediate pointers const qualified}}

  int *intptr;
  const int *intptrc = (const int *)intptr;    // no warning

  const char **charptrptrc;
  char **charptrptr = (char **)charptrptrc; // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}

  const char *constcharptr;
  char *charptr = (char *)constcharptr; // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  const char *constcharptr2 = (char *)constcharptr; // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  const char *charptr2 = (char *)charptr; // no warning

#ifdef __cplusplus
  using CharPtr = char *;
  using CharPtrPtr = char **;
  using ConstCharPtrPtr = const char **;
  using CharPtrConstPtr = char *const *;

  char *fy = CharPtr(ptr);	// expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  char **fy1 = CharPtrPtr(ptrptr);	// expected-warning {{cast from 'const char *const *' to 'char **' drops const qualifier}}
  const char **fy2 = ConstCharPtrPtr(ptrptr);	// expected-warning {{cast from 'const char *const *' to 'const char **' drops const qualifier}}
  char *const *fy3 = CharPtrConstPtr(ptrptr);	// expected-warning {{cast from 'const char *const' to 'char *const' drops const qualifier}}
  const char **fy4 = ConstCharPtrPtr(ptrcptr);	// expected-warning {{cast from 'char *const *' to 'const char **' drops const qualifier}}

  using ConstVoidPtr = const void *;
  char *fz = CharPtr(uintptr_t(ConstVoidPtr(ptr)));	// no warning
  char *fz1 = CharPtr(ConstVoidPtr(ptr));	// expected-warning {{cast from 'const void *' to 'char *' drops const qualifier}}

  char *fvol2 = CharPtr(vol); // expected-warning {{cast from 'volatile char *' to 'char *' drops volatile qualifier}}
  char *fvolc2 = CharPtr(volc); // expected-warning {{cast from 'const volatile char *' to 'char *' drops const and volatile qualifiers}}

  using ConstIntPtrPtr = const int **;
  using VolitileIntPtrPtr = volatile int **;
  const int **fintptrptrc = ConstIntPtrPtr(intptrptr); // expected-warning {{cast from 'int **' to 'ConstIntPtrPtr' (aka 'const int **') must have all intermediate pointers const qualified}}
  volatile int **fintptrptrv = VolitileIntPtrPtr(intptrptr); // expected-warning {{cast from 'int **' to 'VolitileIntPtrPtr' (aka 'volatile int **') must have all intermediate pointers const qualified}}

  using ConstIntPtr = const int *;
  const int *fintptrc = ConstIntPtr(intptr);    // no warning

  char **fcharptrptr = CharPtrPtr(charptrptrc); // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}

  char *fcharptr = CharPtr(constcharptr); // expected-warning {{cast from 'const char *' to 'char *' drops const qualifier}}
  const char *fcharptr2 = CharPtr(charptr); // no warning
#endif
}

void bar_0(void) {
  struct C {
    const int a;
    int b;
  };

  const struct C S = {0, 0};

  *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  *(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}

#ifdef __cplusplus
  using IntPtr = int *;
  *(IntPtr(&S.a)) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  *(IntPtr(&S.b)) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
#endif
}

void bar_1(void) {
  struct C {
    const int a;
    int b;
  };

  struct C S = {0, 0};
  S.b = 0; // no warning

  *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  *(int *)(&S.b) = 0; // no warning

#ifdef __cplusplus
  using IntPtr = int *;
  *(IntPtr(&S.a)) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
  *(IntPtr(&S.b)) = 0; // no warning
#endif
}