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

[redi at gcc dot gnu dot org]

------- Comment #3 from redi at gcc dot gnu dot org  2009-11-20 18:49 -------
(In reply to comment #2)
> In standard C, a size 0 array is forbidden, at least in C99 doc I have handy,

Yes, but it's a long-standing GNU extension:
http://gcc.gnu.org/onlinedocs/gcc-4.4.2/gcc/Zero-Length.html#Zero-Length

The C++ front end says:
      /* As an extension we allow zero-sized arrays.  We always allow
         them in system headers because glibc uses them.  */

Maybe the C++ front-end could be made stricter, so that it accepts char b[0]
(like the C front end) but not char b[] (which is a C99 flexible array member,
and must be the last member)


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