gcc/testsuite/gcc.dg/c11-atomic-4.c

   1 /* PR c/69002 */
   2 /* Test we diagnose accessing elements of atomic structures or unions,
   3    which is undefined behavior (C11 6.5.2.3#5).  */
   4 /* { dg-do compile } */
   5 /* { dg-options "-std=c11 -pedantic-errors" } */
   6
   7 struct S { int x; };
   8 union U { int x; };
   9
  10 int
  11 fn1 (_Atomic struct S p)
  12 {
  13   int e = 0 && p.x;
  14   return p.x + e; /* { dg-warning "accessing a member .x. of an atomic structure" } */
  15 }
  16
  17 int
  18 fn2 (_Atomic struct S *p)
  19 {
  20   int e = 1 || p->x;
  21   return p->x + e; /* { dg-warning "accessing a member .x. of an atomic structure" } */
  22 }
  23
  24 void
  25 fn3 (_Atomic struct S p, int x)
  26 {
  27   p.x = x; /* { dg-warning "accessing a member .x. of an atomic structure" } */
  28 }
  29
  30 void
  31 fn4 (_Atomic struct S *p, int x)
  32 {
  33   p->x = x; /* { dg-warning "accessing a member .x. of an atomic structure" } */
  34 }
  35
  36 int
  37 fn5 (_Atomic struct S p)
  38 {
  39   /* This is OK: Members can be safely accessed using a non-atomic
  40      object which is assigned to or from the atomic object.  */
  41   struct S s = p;
  42   return s.x;
  43 }
  44
  45 int
  46 fn6 (_Atomic struct S *p)
  47 {
  48   struct S s = *p;
  49   return s.x;
  50 }
  51
  52 int
  53 fn7 (_Atomic union U p)
  54 {
  55   int e = 0 && p.x;
  56   return p.x + e; /* { dg-warning "accessing a member .x. of an atomic union" } */
  57 }
  58
  59 int
  60 fn8 (_Atomic union U *p)
  61 {
  62   int e = 1 || p->x;
  63   return p->x + e; /* { dg-warning "accessing a member .x. of an atomic union" } */
  64 }
  65
  66 void
  67 fn9 (_Atomic union U p, int x)
  68 {
  69   p.x = x; /* { dg-warning "accessing a member .x. of an atomic union" } */
  70 }
  71
  72 void
  73 fn10 (_Atomic union U *p, int x)
  74 {
  75   p->x = x; /* { dg-warning "accessing a member .x. of an atomic union" } */
  76 }
  77
  78 int
  79 fn11 (_Atomic union U p)
  80 {
  81   /* This is OK: Members can be safely accessed using a non-atomic
  82      object which is assigned to or from the atomic object.  */
  83   union U s = p;
  84   return s.x;
  85 }
  86
  87 int
  88 fn12 (_Atomic union U *p)
  89 {
  90   union U s = *p;
  91   return s.x;
  92 }