gcc/testsuite/gcc.dg/Wstringop-truncation-4.c

   1 /* PR tree-optimization/85700 - Spurious -Wstringop-truncation warning
   2    with strncat
   3    { dg-do compile }
   4    { dg-options "-O2 -Wno-stringop-overflow -Wstringop-truncation -ftrack-macro-expansion=0" } */
   5
   6 #define NOIPA __attribute__ ((noipa))
   7 #define strncat __builtin_strncat
   8 #define strlen __builtin_strlen
   9
  10 extern char a4[4], b4[4], ax[];
  11
  12 NOIPA void cat_a4_s1_1 (void)
  13 {
  14   /* There is no truncation here but since the bound of 1 equals
  15      the length of the source string it's likely a mistake that
  16      could cause overflow so it's diagnosed by -Wstringop-overflow */
  17   strncat (a4, "1", 1);
  18 }
  19
  20 NOIPA void cat_a4_s1_2 (void)
  21 {
  22   strncat (a4, "1", 2);
  23 }
  24
  25 NOIPA void cat_a4_s1_3 (void)
  26 {
  27   strncat (a4, "1", 3);
  28 }
  29
  30 NOIPA void cat_a4_s1_4 (void)
  31 {
  32   /* There is no truncation here but since the bound of 1 equals
  33      the length of the source string it's likely a mistake that
  34      could cause overflow so it's diagnosed by -Wstringop-overflow */
  35   strncat (a4, "1", 4);
  36 }
  37
  38 NOIPA void cat_a4_s1_5 (void)
  39 {
  40   /* A bound in excess of the destination size is diagnosed by
  41      -Wstringop-overflow.  */
  42   strncat (a4, "1", 5);
  43 }
  44
  45 NOIPA void cat_a4_s1_dlen (void)
  46 {
  47   strncat (a4, "1", sizeof a4 - strlen (a4) - 1);
  48 }
  49
  50 NOIPA void cat_a4_s2_dlen (void)
  51 {
  52   strncat (a4, "12", sizeof a4 - strlen (a4) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
  53 }
  54
  55 NOIPA void cat_a4_b4_dlen (void)
  56 {
  57   strncat (a4, b4, sizeof a4 - strlen (a4) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
  58 }
  59
  60 NOIPA void cat_ax_b4_dlen (void)
  61 {
  62   strncat (ax, b4, 32 - strlen (ax) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
  63 }