gcc/testsuite/c-c++-common/Wuse-after-free.c

   1 /* Exercise basic cases of -Wuse-after-free without optimization.
   2    { dg-do compile }
   3    { dg-options "-O0 -Wall" } */
   4
   5 typedef __SIZE_TYPE__ size_t;
   6
   7 #if __cplusplus
   8 #  define EXTERN_C extern "C"
   9 #else
  10 #  define EXTERN_C extern
  11 #endif
  12
  13 EXTERN_C void* alloca (size_t);
  14
  15 EXTERN_C void* calloc (size_t, size_t);
  16 EXTERN_C void* malloc (size_t);
  17
  18 EXTERN_C void free (void*);
  19
  20
  21 void sink (void *);
  22
  23 extern void* evp;
  24 extern void* evpa[];
  25
  26 extern int ei;
  27
  28 struct List { struct List *next; };
  29
  30 void nowarn_free (void *vp, struct List *lp)
  31 {
  32   {
  33     free (vp);
  34     vp = 0;
  35     sink (vp);
  36   }
  37   {
  38     free (evp);
  39     evp = 0;
  40     sink (evp);
  41   }
  42   {
  43     free (evpa[0]);
  44     evpa[0] = 0;
  45     sink (evpa[0]);
  46   }
  47   {
  48     void *vp = evpa[0];
  49     free (evpa[1]);
  50     sink (vp);
  51   }
  52   {
  53     void *p = evpa[1];
  54     if (ei & 1)
  55       free (p);
  56     if (ei & 2)
  57       sink (p);
  58   }
  59   {
  60     struct List *next = lp->next;
  61     free (lp);
  62     free (next);
  63   }
  64 }
  65
  66 void nowarn_free_arg (void *p, void *q)
  67 {
  68   free (p);
  69   if (q)
  70     free (q);
  71 }
  72
  73 void nowarn_free_extern (void)
  74 {
  75   extern void *ep, *eq;
  76   free (ep);
  77   ep = eq;
  78   free (ep);
  79 }
  80
  81 void nowarn_free_assign (void)
  82 {
  83   extern void *ep;
  84   free (ep);
  85   ep = 0;
  86   free (ep);
  87 }
  88
  89 #pragma GCC diagnostic push
  90 /* Verify that -Wuse-after-free works with #pragma diagnostic.  Note
  91    that the option name should not need to include a trailing =, even
  92    though it's a multi-level option.  (specifying the level after
  93    the option, as in "-Wuse-after-free=2", doesn't work.  */
  94 #pragma GCC diagnostic ignored "-Wuse-after-free"
  95
  96 void nowarn_double_free_suppressed (void *p)
  97 {
  98   free (p);
  99   free (p);
 100 }
 101
 102 #pragma GCC diagnostic pop
 103
 104 void warn_double_free_arg (void *p)
 105 {
 106   free (p);                   // { dg-message "call to '\(void \)?free\(\\(void\\*\\)\)?'" "note" }
 107   // Verify exactly one warning is issued.
 108   free (p);                   // { dg-warning "\\\-Wuse-after-free" }
 109                               // { dg-bogus "\\\-Wuse-after-free" "duplicate warning" { target *-*-* } .-1 }
 110
 111 }
 112
 113 void warn_double_free_extern (void)
 114 {
 115   /* GCC assumes free() clobbers global memory and the warning is
 116      too simplistic to see through that assumption.  */
 117   extern void *ep, *eq;
 118   {
 119     eq = ep;
 120     free (ep);                // { dg-message "call to 'free'" "pr??????" { xfail *-*-* } }
 121     free (eq);                // { dg-warning "\\\-Wuse-after-free" "pr??????" { xfail *-*-* } }
 122   }
 123 }
 124
 125 void warn_deref_after_free (int *p, int i)
 126 {
 127   int *q0 = p, *q1 = p + 1, *qi = p + i;
 128   free (p);                   // { dg-message "call to '\(void \)?free\(\\(void\\*\\)\)?'" "note" }
 129   *p = 0;                     // { dg-warning "\\\-Wuse-after-free" }
 130
 131   *q0 = 0;                    // { dg-warning "\\\-Wuse-after-free" }
 132   *q1 = 0;                    // { dg-warning "\\\-Wuse-after-free" }
 133   *qi = 0;                    // { dg-warning "\\\-Wuse-after-free" }
 134 }
 135
 136 void warn_array_ref_after_free (int *p, int i)
 137 {
 138   free (p);                   // { dg-message "call to '\(void \)?free\(\\(void\\*\\)\)?'" "note" }
 139   p[i] = 0;                   // { dg-warning "\\\-Wuse-after-free" }
 140 }
 141
 142 void nowarn_free_list (struct List *head)
 143 {
 144   for (struct List *p = head, *q; p; p = q)
 145     {
 146       q = p->next;
 147       free (p);
 148     }
 149 }
 150
 151 void warn_free_list (struct List *head)
 152 {
 153   struct List *p = head;
 154   for (; p; p = p->next)      // { dg-warning "\\\[-Wuse-after-free" }
 155     free (p);                 // { dg-message "call to '\(void \)?free\(\\(void\\*\\)\)?'" "note" }
 156 }
 157
 158
 159 void warn_free (void *vp)
 160 {
 161   {
 162     free (vp);                // { dg-message "call to '\(void \)?free\(\\(void\\*\\)\)?'" "note" }
 163     evp = vp;                 // { dg-warning "-Wuse-after-free" }
 164     evpa[0] = vp;             // { dg-warning "-Wuse-after-free" }
 165     evpa[1] = evp;
 166   }
 167 }