pointer-arith-2.c

来自「linux下编程用 编译软件」· C语言 代码 · 共 42 行

/* Test diagnostics for arithmetic on void and function pointers.
   Test with -Wpointer-arith.  */
/* Origin: Joseph Myers <[e-mail]> */
/* { dg-do compile } */
/* { dg-options "-Wpointer-arith" } */

void *p;
void (*f)(void);

void
g (void)
{
  p + 0; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p + 1; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  0 + p; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  1 + p; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p - 0; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p - 1; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p += 0; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p += 1; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p -= 0; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  p -= 1; /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" } */
  f + 0; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f + 1; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  0 + f; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  1 + f; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f - 0; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f - 1; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f += 0; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f += 1; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f -= 0; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  f -= 1; /* { dg-warning "warning: pointer to a function used in arithmetic" } */
  p[0]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
  /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 33 } */
  0[p]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
  /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 35 } */
  f[0]; /* { dg-error "error: subscripted value is pointer to function" } */
  0[f]; /* { dg-error "error: subscripted value is pointer to function" } */
  p - p; /* { dg-warning "warning: pointer of type 'void \\*' used in subtraction" } */
  f - f; /* { dg-warning "warning: pointer to a function used in subtraction" } */
}