[Bug c/106778] New: libcpp/makeuname2c.cc:454: sanity check in wrong place ?

[dcb314 at hotmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106778

            Bug ID: 106778
           Summary: libcpp/makeuname2c.cc:454: sanity check in wrong place
                    ?
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Static analyser cppcheck can be made to say:

libcpp/makeuname2c.cc:454:19: style: Array index 'off' is used before limits
check. [arrayIndexThenCheck]

Source code is

      assert (tree[off] == 0 && off < tree_size);

Suggest sanity check array index before use, not after.