gcc/testsuite/c-c++-common/analyzer/sprintf-2.c

   1 /* See e.g. https://en.cppreference.com/w/c/io/fprintf
   2    and https://www.man7.org/linux/man-pages/man3/sprintf.3.html */
   3
   4 extern int
   5 sprintf(char* dst, const char* fmt, ...)
   6   __attribute__((__nothrow__));
   7
   8 #include "../../gcc.dg/analyzer/analyzer-decls.h"
   9
  10 int
  11 test_passthrough (char* dst, const char* fmt)
  12 {
  13   /* This assumes that fmt doesn't have any arguments.  */
  14   return sprintf (dst, fmt);
  15 }
  16
  17 void
  18 test_known (void)
  19 {
  20   char buf[10];
  21   int res = sprintf (buf, "foo");
  22   /* TODO: ideally we would know the value of "res" is 3,
  23      and known the content and strlen of "buf" after the call */
  24 }
  25
  26 int
  27 test_null_dst (void)
  28 {
  29   return sprintf (NULL, "hello world"); /* { dg-warning "use of NULL where non-null expected" } */
  30 }
  31
  32 int
  33 test_null_fmt (char *dst)
  34 {
  35   return sprintf (dst, NULL);  /* { dg-warning "use of NULL where non-null expected" } */
  36 }
  37
  38 int
  39 test_uninit_dst (void)
  40 {
  41   char *dst;
  42   return sprintf (dst, "hello world"); /* { dg-warning "use of uninitialized value 'dst'" } */
  43 }
  44
  45 int
  46 test_uninit_fmt_ptr (char *dst)
  47 {
  48   const char *fmt;
  49   return sprintf (dst, fmt); /* { dg-warning "use of uninitialized value 'fmt'" } */
  50 }
  51
  52 void
  53 test_strlen_1 (void)
  54 {
  55   char buf[10];
  56   sprintf (buf, "msg: %s\n", "abc");
  57   __analyzer_eval (__builtin_strlen (buf) == 8); /* { dg-warning "UNKNOWN" } */
  58   // TODO: ideally would be TRUE
  59 }