My collegue just today noticed that gcc version 3.4.0 behaves a bid odd on Linux
when --pedantic-errors is used as compilation option to C-compiler (gcc):

<helix:/tmp> cat main.c 
#include <stdio.h>
#include <stdlib.h>
int main(void){printf("Hello world\n"); exit(EXIT_SUCCESS);}

<helix:/tmp> gcc --version
gcc (GCC) 3.4.0
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

<helix:/tmp> gcc --pedantic main.c 
<helix:/tmp> gcc --pedantic-errors main.c
In file included from /usr/include/libio.h:32,
                 from /usr/include/stdio.h:65,
                 from main.c:1:
/usr/include/_G_config.h:50: error: invalid use of structure with flexible array
member
<helix:/tmp> 

If g++ is used instead of gcc:

<helix:/tmp> g++ --version
g++ (GCC) 3.4.0
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

<helix:/tmp> g++ --pedantic main.c
<helix:/tmp> g++ --pedantic-errors main.c
<helix:/tmp> 

This problem does not happen on Solaris/HPUX version nor does it happen when
older version (tested with 3.3.3 and 2.95.3) of gcc is used.