[Bug c/63591] New: No syntax error yielded for semicolons inside a function proto, instead code with memory corruption can be created

["k.s.matheussen at notam02 dot no" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63591

            Bug ID: 63591
           Summary: No syntax error yielded for semicolons inside a
                    function proto, instead code with memory corruption
                    can be created
           Product: gcc
           Version: 4.8.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: k.s.matheussen at notam02 dot no

This code should, as far as I know, not be legal C code:

extern int afunction(
                     int anint,
                     struct Happ *happ; // <- Extra semicolon
                     );

int afunction(
              int velocityvelocity,
              struct Happ *happ
              )
{
  return 208;
}


Gcc does not complain about this code, even with -Wall and -Werror.

I'm also seeing memory corruption in a larger program I'm working on,
because of this extra misplaced semicolon, but I haven't been able
to create a smaller example doing this. Please let me know if you need
the larger example causing memory corruption.

I consider this bug (I assume it is a bug) quite serious.
If adding this extra semicolon by mistake (like I did), things appear
to work as normal, whille possibly getting serious bugs which are
hard to trace.