check_format_string.c

   1 #include <string.h>
   2 #include "smatch.h"
   3 #include "smatch_extra.h"
   4
   5 static int my_id;
   6
   7 static void match_printf(const char *fn, struct expression *expr, void *unused)
   8 {
   9         struct expression *format;
  10
  11         format = get_argument_from_call_expr(expr->args, 0);
  12         if (format -> type != EXPR_STRING)
  13             sm_msg("warn: format strings should be constant to avoid format string vulnerabilities");
  14 }
  15
  16 void check_format_string(int id)
  17 {
  18         if (!option_spammy)
  19                 return;
  20         my_id = id;
  21         add_function_hook("printf", &match_printf, (void *)0);
  22 }