[Bug middle-end/83404] New: bogus stringop-overflow warning

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83404

            Bug ID: 83404
           Summary: bogus stringop-overflow warning
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bernd.edlinger at hotmail dot de
  Target Milestone: ---

$ cat test.c
#include <string.h>
main()
{
  char x[12];
  strncpy(x, "", 12);
  strncat(x, "aa", 1);
  strncat(x, "aa", 2);
  strncat(x, "aa", 3);
}
$ gcc -Wall -W test.c
test.c: In function ‘main’:
test.c:7:3: warning: ‘strncat’ specified bound 2 equals source length
[-Wstringop-overflow=]
   strncat(x, "aa", 2);
   ^~~~~~~~~~~~~~~~~~~


The warning here is a bit surprising to me.