[Bug c++/42121] g++ should warn or error on internal 0 size array in struct

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42121

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.10.27 21:31:30
     Ever Confirmed|0                           |1

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> 2010-10-27 
21:31:30 UTC ---
The C++ front end is far too permissive, the comments below show what should
change for compatibility with the C front end:

struct bogus
{
    int a;
    char b[];   // should be rejected, b[0] is ok
    int c;
};

struct bogus2 {
  int x[];      // should be rejected, x[0] is ok
};

struct ok {
  int a;
  int x[];
};

struct gnu_extension
{
  struct ok a;
};

If bogus::b and bogus2::x are declared as zero-length arrays, rather than
flexible array members, then they are accepted by the C front end.