Re: Unnamed Structure declaration

Re: Unnamed Structure declaration

[Rob.McConnell]

> This is an easy one though.

> > struct wibble {
> >         int a;
> > };
> > struct wabble {
> >     struct wibble;      /**** Compiler throws a wobbly here! ****/
> >     int b;
> > };

> This isn't valid ISO C.  Some compilers support this as an extension to
> the ISO C standard, in partticular, the Microsoft compiler does.

Thought as much ; ^ )

> Gcc supported this by default for a while, but there were some issues
> with it, so nowadays gcc only supports this if you use the
> -fms-extensions option.

>From a curiosity point of view, what issues cropped up?

BTW, I noticed on earlier version of GCC (e.g. 2.96), there were quite a
few bugs surrounding anonymous struct/unions and also empty structs (e.g.
struct {}).  In particular I found that a field of a structure immediately
after an empty struct definition was not initialised correctly (defaulted
to 0). This applies to anonymous and named structs.

e.g. struct wibble {
      struct {};        /*** Empty struct definition ***/
      int a; };

      struct wibble wibble_s = {.a = 1};

Here, the value of field "a" should be initialised to 1, but in fact it is
0 if you print the value out or look at the actual hexdump using "objdump
-s ....".

Do you know when these bugs were fixed so that I can say to people "use GCC
versions later than x.y" for my work?

Many thanks for your speedy and accurate response!

Cheers,

Rob : )

Re: Unnamed Structure declaration

[Jim Wilson]

On Tue, 2004-03-02 at 03:30, Rob.McConnell@Zarlink.Com wrote:
> >From a curiosity point of view, what issues cropped up?

It was accidentally used in some places where it wasn't wanted.  For
instance, the linux kernel.

Also, some people pointed out that it adds nothing to the language. 
Allowing anonymous unions inside structures provides a useful feature,
and that one is still enabled by default.  This feature is also a
standard part of C++.  However anonymous structures inside structures
doesn't solve any real problem, and it some people objected to it, so it
is now enabled by an option.

> Do you know when these bugs were fixed so that I can say to people "use GCC
> versions later than x.y" for my work?

Offhand, I don't know.

This is probably target dependent and testcase dependent.  There have
been a number of problems with empty structures over the years, and
these problems have been fixed at different times.  Some of the fixes
were to machine independent code, and some to machine dependent code.

Empty structures are not valid ISO C by the way.  They are a GNU C
extension.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com

Re: Unnamed Structure declaration

[Jim Wilson]

Rob.McConnell@Zarlink.Com wrote:
> I'm a newbie here, so I hope this is the right ML to send this query to.

There is no need to send it to two mailing lists.  Just pick one. 
However, it is better to submit bug reports into our bugzilla bug 
database, as we don't track bugs reported by email.  See
     http://gcc.gnu.org/bugs.html
This is an easy one though.

> struct wibble {
>         int a;
> };
> struct wabble {
>     struct wibble;      /**** Compiler throws a wobbly here! ****/
>     int b;
> };

This isn't valid ISO C.  Some compilers support this as an extension to 
the ISO C standard, in partticular, the Microsoft compiler does.

Gcc supported this by default for a while, but there were some issues 
with it, so nowadays gcc only supports this if you use the 
-fms-extensions option.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com

Unnamed Structure declaration

[Rob.McConnell]

[-- Attachment #1: Type: text/plain, Size: 2079 bytes --]





Hi Folks,

I'm a newbie here, so I hope this is the right ML to send this query to.

I have a problem when compiling the test.c program below using gcc 3.3 (C
compiler) under Linux (RH 7.2) on my i686 architecture.  The compiler
doesn't allow an unnamed struct inside a named struct even though the
unnamed struct ("wibble") is declared before it.

I have used "gcc -Wall -save-temps test.c -o test" to generate the
preprocessed "test.i" file attached.  Here is the original source of only a
few lines to give you a quick understanding of the problem.

#include <stdio.h>

struct wibble {
        int a;
};

struct wabble {
    struct wibble;      /**** Compiler throws a wobbly here! ****/
    int b;
};

struct wabble wabble_init = {
        {.a = 1,},
        .b = 4,
};

int main(void)
{
    struct wabble *ptr = &wabble_init;

    ptr->a=10;
    ptr->b=12;
    printf("Sizeof struct wibble = %d bytes\n", sizeof(struct wibble));
    printf("Sizeof struct wabble = %d bytes\n", sizeof(struct wabble));
    return 0;
}

The compiler produces the following error message:

test.c:8: warning: declaration does not declare anything
test.c:13: warning: braces around scalar initializer
test.c:13: warning: (near initialization for `wabble_init.b')
test.c:13: error: field name not in record or union initializer
test.c:13: error: (near initialization for `wabble_init.b')
test.c: In function `main':
test.c:21: error: structure has no member named `a'


Now under earlier versions of gcc (3.2 and 2.96) no errors or warnings are
produced.  I have also compiled this code under MS VC++ Version 6.0 with
success (not that I program under Windozzz).  Surely, the elements/fields
of this unnamed structure wibble should be accessible as though they were
part of the main structure "wabble" (e.g. ptr->a).  This is how earlier
versions of gcc handled this and is a feature that I definitely use/need
for my code.

Can someone let me know if this bug has been fixed in later releases of gcc
and why does gcc 3.3 generate this error?

Many TIA,

Rob : )


(See attached file: test.i)

[-- Attachment #2: test.i --]
[-- Type: application/octet-stream, Size: 18882 bytes --]

# 1 "test.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "test.c"
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 1 3 4
# 37 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
# 1 "/usr/include/features.h" 1 3 4
# 283 "/usr/include/features.h" 3 4
# 1 "/usr/include/sys/cdefs.h" 1 3 4
# 284 "/usr/include/features.h" 2 3 4
# 312 "/usr/include/features.h" 3 4
# 1 "/usr/include/gnu/stubs.h" 1 3 4
# 313 "/usr/include/features.h" 2 3 4
# 38 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 2 3 4





# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 213 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 3 4
typedef unsigned int size_t;
# 44 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 2 3 4

# 1 "/usr/include/bits/types.h" 1 3 4
# 29 "/usr/include/bits/types.h" 3 4
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 30 "/usr/include/bits/types.h" 2 3 4


typedef unsigned char __u_char;
typedef unsigned short __u_short;
typedef unsigned int __u_int;
typedef unsigned long __u_long;

__extension__ typedef unsigned long long int __u_quad_t;
__extension__ typedef long long int __quad_t;
# 49 "/usr/include/bits/types.h" 3 4
typedef signed char __int8_t;
typedef unsigned char __uint8_t;
typedef signed short int __int16_t;
typedef unsigned short int __uint16_t;
typedef signed int __int32_t;
typedef unsigned int __uint32_t;

__extension__ typedef signed long long int __int64_t;
__extension__ typedef unsigned long long int __uint64_t;

typedef __quad_t *__qaddr_t;

typedef __u_quad_t __dev_t;
typedef __u_int __uid_t;
typedef __u_int __gid_t;
typedef __u_long __ino_t;
typedef __u_int __mode_t;
typedef __u_int __nlink_t;
typedef long int __off_t;
typedef __quad_t __loff_t;
typedef int __pid_t;
typedef int __ssize_t;
typedef __u_long __rlim_t;
typedef __u_quad_t __rlim64_t;
typedef __u_int __id_t;

typedef struct
  {
    int __val[2];
  } __fsid_t;


typedef int __daddr_t;
typedef char *__caddr_t;
typedef long int __time_t;
typedef unsigned int __useconds_t;
typedef long int __suseconds_t;
typedef long int __swblk_t;

typedef long int __clock_t;


typedef int __clockid_t;


typedef int __timer_t;






typedef int __key_t;


typedef unsigned short int __ipc_pid_t;



typedef long int __blksize_t;




typedef long int __blkcnt_t;
typedef __quad_t __blkcnt64_t;


typedef __u_long __fsblkcnt_t;
typedef __u_quad_t __fsblkcnt64_t;


typedef __u_long __fsfilcnt_t;
typedef __u_quad_t __fsfilcnt64_t;


typedef __u_quad_t __ino64_t;


typedef __loff_t __off64_t;


typedef long int __t_scalar_t;
typedef unsigned long int __t_uscalar_t;


typedef int __intptr_t;


typedef unsigned int __socklen_t;




# 1 "/usr/include/bits/pthreadtypes.h" 1 3 4
# 23 "/usr/include/bits/pthreadtypes.h" 3 4
# 1 "/usr/include/bits/sched.h" 1 3 4
# 68 "/usr/include/bits/sched.h" 3 4
struct __sched_param
  {
    int __sched_priority;
  };
# 24 "/usr/include/bits/pthreadtypes.h" 2 3 4


struct _pthread_fastlock
{
  long int __status;
  int __spinlock;

};



typedef struct _pthread_descr_struct *_pthread_descr;





typedef struct __pthread_attr_s
{
  int __detachstate;
  int __schedpolicy;
  struct __sched_param __schedparam;
  int __inheritsched;
  int __scope;
  size_t __guardsize;
  int __stackaddr_set;
  void *__stackaddr;
  size_t __stacksize;
} pthread_attr_t;



typedef struct
{
  struct _pthread_fastlock __c_lock;
  _pthread_descr __c_waiting;
} pthread_cond_t;



typedef struct
{
  int __dummy;
} pthread_condattr_t;


typedef unsigned int pthread_key_t;





typedef struct
{
  int __m_reserved;
  int __m_count;
  _pthread_descr __m_owner;
  int __m_kind;
  struct _pthread_fastlock __m_lock;
} pthread_mutex_t;



typedef struct
{
  int __mutexkind;
} pthread_mutexattr_t;



typedef int pthread_once_t;
# 140 "/usr/include/bits/pthreadtypes.h" 3 4
typedef unsigned long int pthread_t;
# 144 "/usr/include/bits/types.h" 2 3 4
# 46 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 2 3 4
# 54 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
typedef struct _IO_FILE FILE;
# 64 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
typedef struct _IO_FILE __FILE;
# 74 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
# 1 "/usr/include/libio.h" 1 3 4
# 32 "/usr/include/libio.h" 3 4
# 1 "/usr/include/_G_config.h" 1 3 4
# 14 "/usr/include/_G_config.h" 3 4
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 325 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 3 4
typedef long int wchar_t;
# 354 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 3 4
typedef unsigned int wint_t;
# 15 "/usr/include/_G_config.h" 2 3 4
# 24 "/usr/include/_G_config.h" 3 4
# 1 "/usr/include/wchar.h" 1 3 4
# 48 "/usr/include/wchar.h" 3 4
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 49 "/usr/include/wchar.h" 2 3 4

# 1 "/usr/include/bits/wchar.h" 1 3 4
# 51 "/usr/include/wchar.h" 2 3 4
# 67 "/usr/include/wchar.h" 3 4
typedef struct
{
  int __count;
  union
  {
    wint_t __wch;
    char __wchb[4];
  } __value;
} __mbstate_t;
# 25 "/usr/include/_G_config.h" 2 3 4

typedef struct
{
  __off_t __pos;
  __mbstate_t __state;
} _G_fpos_t;
typedef struct
{
  __off64_t __pos;
  __mbstate_t __state;
} _G_fpos64_t;
# 44 "/usr/include/_G_config.h" 3 4
# 1 "/usr/include/gconv.h" 1 3 4
# 28 "/usr/include/gconv.h" 3 4
# 1 "/usr/include/wchar.h" 1 3 4
# 48 "/usr/include/wchar.h" 3 4
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 49 "/usr/include/wchar.h" 2 3 4
# 29 "/usr/include/gconv.h" 2 3 4


# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stddef.h" 1 3 4
# 32 "/usr/include/gconv.h" 2 3 4





enum
{
  __GCONV_OK = 0,
  __GCONV_NOCONV,
  __GCONV_NODB,
  __GCONV_NOMEM,

  __GCONV_EMPTY_INPUT,
  __GCONV_FULL_OUTPUT,
  __GCONV_ILLEGAL_INPUT,
  __GCONV_INCOMPLETE_INPUT,

  __GCONV_ILLEGAL_DESCRIPTOR,
  __GCONV_INTERNAL_ERROR
};



enum
{
  __GCONV_IS_LAST = 0x0001,
  __GCONV_IGNORE_ERRORS = 0x0002
};



struct __gconv_step;
struct __gconv_step_data;
struct __gconv_loaded_object;
struct __gconv_trans_data;



typedef int (*__gconv_fct) (struct __gconv_step *, struct __gconv_step_data *,
                            __const unsigned char **, __const unsigned char *,
                            unsigned char **, size_t *, int, int);


typedef int (*__gconv_init_fct) (struct __gconv_step *);
typedef void (*__gconv_end_fct) (struct __gconv_step *);



typedef int (*__gconv_trans_fct) (struct __gconv_step *,
                                  struct __gconv_step_data *, void *,
                                  __const unsigned char *,
                                  __const unsigned char **,
                                  __const unsigned char *, unsigned char **,
                                  size_t *);


typedef int (*__gconv_trans_context_fct) (void *, __const unsigned char *,
                                          __const unsigned char *,
                                          unsigned char *, unsigned char *);


typedef int (*__gconv_trans_query_fct) (__const char *, __const char ***,
                                        size_t *);


typedef int (*__gconv_trans_init_fct) (void **, const char *);
typedef void (*__gconv_trans_end_fct) (void *);

struct __gconv_trans_data
{

  __gconv_trans_fct __trans_fct;
  __gconv_trans_context_fct __trans_context_fct;
  __gconv_trans_end_fct __trans_end_fct;
  void *__data;
  struct __gconv_trans_data *__next;
};



struct __gconv_step
{
  struct __gconv_loaded_object *__shlib_handle;
  __const char *__modname;

  int __counter;

  char *__from_name;
  char *__to_name;

  __gconv_fct __fct;
  __gconv_init_fct __init_fct;
  __gconv_end_fct __end_fct;



  int __min_needed_from;
  int __max_needed_from;
  int __min_needed_to;
  int __max_needed_to;


  int __stateful;

  void *__data;
};



struct __gconv_step_data
{
  unsigned char *__outbuf;
  unsigned char *__outbufend;



  int __flags;



  int __invocation_counter;



  int __internal_use;

  __mbstate_t *__statep;
  __mbstate_t __state;



  struct __gconv_trans_data *__trans;
};



typedef struct __gconv_info
{
  size_t __nsteps;
  struct __gconv_step *__steps;
  __extension__ struct __gconv_step_data __data [];
} *__gconv_t;
# 45 "/usr/include/_G_config.h" 2 3 4
typedef union
{
  struct __gconv_info __cd;
  struct
  {
    struct __gconv_info __cd;
    struct __gconv_step_data __data;
  } __combined;
} _G_iconv_t;

typedef int _G_int16_t __attribute__ ((__mode__ (__HI__)));
typedef int _G_int32_t __attribute__ ((__mode__ (__SI__)));
typedef unsigned int _G_uint16_t __attribute__ ((__mode__ (__HI__)));
typedef unsigned int _G_uint32_t __attribute__ ((__mode__ (__SI__)));
# 33 "/usr/include/libio.h" 2 3 4
# 53 "/usr/include/libio.h" 3 4
# 1 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdarg.h" 1 3 4
# 43 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdarg.h" 3 4
typedef __builtin_va_list __gnuc_va_list;
# 54 "/usr/include/libio.h" 2 3 4
# 160 "/usr/include/libio.h" 3 4
struct _IO_jump_t; struct _IO_FILE;
# 170 "/usr/include/libio.h" 3 4
typedef void _IO_lock_t;





struct _IO_marker {
  struct _IO_marker *_next;
  struct _IO_FILE *_sbuf;



  int _pos;
# 193 "/usr/include/libio.h" 3 4
};


enum __codecvt_result
{
  __codecvt_ok,
  __codecvt_partial,
  __codecvt_error,
  __codecvt_noconv
};
# 261 "/usr/include/libio.h" 3 4
struct _IO_FILE {
  int _flags;




  char* _IO_read_ptr;
  char* _IO_read_end;
  char* _IO_read_base;
  char* _IO_write_base;
  char* _IO_write_ptr;
  char* _IO_write_end;
  char* _IO_buf_base;
  char* _IO_buf_end;

  char *_IO_save_base;
  char *_IO_backup_base;
  char *_IO_save_end;

  struct _IO_marker *_markers;

  struct _IO_FILE *_chain;

  int _fileno;
  int _blksize;
  __off_t _old_offset;



  unsigned short _cur_column;
  signed char _vtable_offset;
  char _shortbuf[1];



  _IO_lock_t *_lock;
# 305 "/usr/include/libio.h" 3 4
  __off64_t _offset;





  void *__pad1;
  void *__pad2;

  int _mode;

  char _unused2[15 * sizeof (int) - 2 * sizeof (void *)];

};


typedef struct _IO_FILE _IO_FILE;


struct _IO_FILE_plus;

extern struct _IO_FILE_plus _IO_2_1_stdin_;
extern struct _IO_FILE_plus _IO_2_1_stdout_;
extern struct _IO_FILE_plus _IO_2_1_stderr_;
# 344 "/usr/include/libio.h" 3 4
typedef __ssize_t __io_read_fn (void *__cookie, char *__buf, size_t __nbytes);







typedef __ssize_t __io_write_fn (void *__cookie, __const char *__buf,
                                 size_t __n);







typedef int __io_seek_fn (void *__cookie, __off64_t *__pos, int __w);


typedef int __io_close_fn (void *__cookie);
# 396 "/usr/include/libio.h" 3 4
extern int __underflow (_IO_FILE *) ;
extern int __uflow (_IO_FILE *) ;
extern int __overflow (_IO_FILE *, int) ;
extern wint_t __wunderflow (_IO_FILE *) ;
extern wint_t __wuflow (_IO_FILE *) ;
extern wint_t __woverflow (_IO_FILE *, wint_t) ;
# 426 "/usr/include/libio.h" 3 4
extern int _IO_getc (_IO_FILE *__fp) ;
extern int _IO_putc (int __c, _IO_FILE *__fp) ;
extern int _IO_feof (_IO_FILE *__fp) ;
extern int _IO_ferror (_IO_FILE *__fp) ;

extern int _IO_peekc_locked (_IO_FILE *__fp) ;





extern void _IO_flockfile (_IO_FILE *) ;
extern void _IO_funlockfile (_IO_FILE *) ;
extern int _IO_ftrylockfile (_IO_FILE *) ;
# 456 "/usr/include/libio.h" 3 4
extern int _IO_vfscanf (_IO_FILE * __restrict, const char * __restrict,
                        __gnuc_va_list, int *__restrict) ;
extern int _IO_vfprintf (_IO_FILE *__restrict, const char *__restrict,
                         __gnuc_va_list) ;
extern __ssize_t _IO_padn (_IO_FILE *, int, __ssize_t) ;
extern size_t _IO_sgetn (_IO_FILE *, void *, size_t) ;

extern __off64_t _IO_seekoff (_IO_FILE *, __off64_t, int, int) ;
extern __off64_t _IO_seekpos (_IO_FILE *, __off64_t, int) ;

extern void _IO_free_backup_area (_IO_FILE *) ;
# 75 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 2 3 4
# 89 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
typedef _G_fpos_t fpos_t;
# 138 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
# 1 "/usr/include/bits/stdio_lim.h" 1 3 4
# 139 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 2 3 4



extern FILE *stdin;
extern FILE *stdout;
extern FILE *stderr;
# 153 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int remove (__const char *__filename) ;

extern int rename (__const char *__old, __const char *__new) ;




extern FILE *tmpfile (void) ;
# 172 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern char *tmpnam (char *__s) ;




extern char *tmpnam_r (char *__s) ;
# 189 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern char *tempnam (__const char *__dir, __const char *__pfx)
     __attribute__ ((__malloc__));




extern int fclose (FILE *__stream) ;

extern int fflush (FILE *__stream) ;



extern int fflush_unlocked (FILE *__stream) ;
# 212 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern FILE *fopen (__const char *__restrict __filename,
                    __const char *__restrict __modes) ;

extern FILE *freopen (__const char *__restrict __filename,
                      __const char *__restrict __modes,
                      FILE *__restrict __stream) ;
# 242 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern FILE *fdopen (int __fd, __const char *__modes) ;
# 265 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern void setbuf (FILE *__restrict __stream, char *__restrict __buf) ;



extern int setvbuf (FILE *__restrict __stream, char *__restrict __buf,
                    int __modes, size_t __n) ;




extern void setbuffer (FILE *__restrict __stream, char *__restrict __buf,
                       size_t __size) ;


extern void setlinebuf (FILE *__stream) ;




extern int fprintf (FILE *__restrict __stream,
                    __const char *__restrict __format, ...) ;

extern int printf (__const char *__restrict __format, ...) ;

extern int sprintf (char *__restrict __s,
                    __const char *__restrict __format, ...) ;


extern int vfprintf (FILE *__restrict __s, __const char *__restrict __format,
                     __gnuc_va_list __arg) ;

extern int vprintf (__const char *__restrict __format, __gnuc_va_list __arg)
     ;

extern int vsprintf (char *__restrict __s, __const char *__restrict __format,
                     __gnuc_va_list __arg) ;



extern int snprintf (char *__restrict __s, size_t __maxlen,
                     __const char *__restrict __format, ...)
     __attribute__ ((__format__ (__printf__, 3, 4)));

extern int vsnprintf (char *__restrict __s, size_t __maxlen,
                      __const char *__restrict __format, __gnuc_va_list __arg)
     __attribute__ ((__format__ (__printf__, 3, 0)));
# 336 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int fscanf (FILE *__restrict __stream,
                   __const char *__restrict __format, ...) ;

extern int scanf (__const char *__restrict __format, ...) ;

extern int sscanf (__const char *__restrict __s,
                   __const char *__restrict __format, ...) ;
# 362 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int fgetc (FILE *__stream) ;
extern int getc (FILE *__stream) ;


extern int getchar (void) ;







extern int getc_unlocked (FILE *__stream) ;
extern int getchar_unlocked (void) ;




extern int fgetc_unlocked (FILE *__stream) ;




extern int fputc (int __c, FILE *__stream) ;
extern int putc (int __c, FILE *__stream) ;


extern int putchar (int __c) ;







extern int fputc_unlocked (int __c, FILE *__stream) ;




extern int putc_unlocked (int __c, FILE *__stream) ;
extern int putchar_unlocked (int __c) ;





extern int getw (FILE *__stream) ;


extern int putw (int __w, FILE *__stream) ;




extern char *fgets (char *__restrict __s, int __n, FILE *__restrict __stream)
     ;
# 428 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern char *gets (char *__s) ;
# 452 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int fputs (__const char *__restrict __s, FILE *__restrict __stream)
     ;
# 462 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int puts (__const char *__s) ;



extern int ungetc (int __c, FILE *__stream) ;



extern size_t fread (void *__restrict __ptr, size_t __size,
                     size_t __n, FILE *__restrict __stream) ;

extern size_t fwrite (__const void *__restrict __ptr, size_t __size,
                      size_t __n, FILE *__restrict __s) ;



extern size_t fread_unlocked (void *__restrict __ptr, size_t __size,
                              size_t __n, FILE *__restrict __stream) ;
extern size_t fwrite_unlocked (__const void *__restrict __ptr, size_t __size,
                               size_t __n, FILE *__restrict __stream) ;




extern int fseek (FILE *__stream, long int __off, int __whence) ;

extern long int ftell (FILE *__stream) ;

extern void rewind (FILE *__stream) ;
# 506 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int fgetpos (FILE *__restrict __stream, fpos_t *__restrict __pos)
     ;

extern int fsetpos (FILE *__stream, __const fpos_t *__pos) ;
# 542 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern void clearerr (FILE *__stream) ;

extern int feof (FILE *__stream) ;

extern int ferror (FILE *__stream) ;



extern void clearerr_unlocked (FILE *__stream) ;
extern int feof_unlocked (FILE *__stream) ;
extern int ferror_unlocked (FILE *__stream) ;




extern void perror (__const char *__s) ;




extern int sys_nerr;
extern __const char *__const sys_errlist[];
# 573 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern int fileno (FILE *__stream) ;




extern int fileno_unlocked (FILE *__stream) ;






extern FILE *popen (__const char *__command, __const char *__modes) ;


extern int pclose (FILE *__stream) ;





extern char *ctermid (char *__s) ;
# 620 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4
extern void flockfile (FILE *__stream) ;



extern int ftrylockfile (FILE *__stream) ;


extern void funlockfile (FILE *__stream) ;
# 644 "/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3/include/stdio.h" 3 4

# 2 "test.c" 2

struct wibble {
        int a;
};

struct wabble {
    struct wibble;
    int b;
};

struct wabble wabble_init = {
        {.a = 1,},
        .b = 4,
};

int main(void)
{
    struct wabble *ptr = &wabble_init;

    ptr->a=10;
    ptr->b=12;
    printf("Sizeof struct wibble = %d bytes\n", sizeof(struct wibble));
    printf("Sizeof struct wabble = %d bytes\n", sizeof(struct wabble));
    return 0;
}