gcc/testsuite/gcc.dg/torture/builtin-sprintf.c

/* PR tree-optimization/86274 - SEGFAULT when logging std::to_string(NAN)
   { dg-do run }
   { dg-options "-O2 -Wall" }
   { dg-additional-options "-Wl,-u,_printf_float" { target newlib_nano_io } } */

#define X        "0xdeadbeef"
#define nan(x)   __builtin_nan (x)

volatile double nan_0 = nan ("0");
volatile double nan_x = nan (X);

int main (void)
{
  char buf[80];

  /* Verify that folded results match those of the library calls.  */
  int cst_n_0 = __builtin_sprintf (buf, "%g", nan ("0"));
  int cst_n_x = __builtin_sprintf (buf, "%g", nan (X));

  int var_n_0 = __builtin_sprintf (buf, "%g", nan_0);
  int var_n_x = __builtin_sprintf (buf, "%g", nan_x);

  if (cst_n_0 != var_n_0)
    __builtin_abort ();

  if (cst_n_x != var_n_x)
    __builtin_abort ();

  return 0;
}