gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-6.c

   1 /* PR tree-optimization/78969 - bogus snprintf truncation warning due to
   2    missing range info
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -Wformat-truncation=2" } */
   5
   6 typedef __SIZE_TYPE__ size_t;
   7
   8 extern int snprintf (char*, size_t, const char*, ...);
   9
  10
  11 void f (unsigned j, char *p)
  12 {
  13   if (j > 999)
  14     j = 0;
  15
  16   snprintf (p, 4, "%3u", j);
  17 }
  18
  19 void g (unsigned j, char *p)
  20 {
  21   if (j > 999)
  22     return;
  23
  24   snprintf (p, 4, "%3u", j);            // { dg-bogus "-Wformat-truncation" }
  25 }
  26
  27
  28 void pr78969_c4 (char * p /* NNN\0" */)
  29 {
  30   for (int idx = 0; idx < 1000; idx++) {
  31     // guaranteed to be in [0-999] range
  32     snprintf (p, 4, "%d", idx);         // { dg-bogus "-Wformat-truncation" }
  33   }
  34 }
  35
  36
  37 void sink (int, ...);
  38
  39 char d[4];
  40
  41 void pr78969_c12 (unsigned i)
  42 {
  43   if (i >= 1000 && i < 10000)
  44     snprintf (d, 4, "%3d", i / 10);     // { dg-bogus "-Wformat-truncation" }
  45   else
  46     sink (i / 10 % 10);
  47 }