Error with unnamed structures

[llewelly@xmission.com]

"Luiz Rafael Culik Guimaraes" <culikr@uol.com.br> writes:

>  Dear friends
> 
>  this code bellow
> 
>  if __GNUC__ < 3 || defined( XWT_GTK_OLD_INHERITANCE )
>  #   define INHERIT( x )         x inherit
>  #   define INH( field )         inherit.field
>  #else
>  #   define INHERIT( x )         x
>  #   define INH( field )         field
>  #endif
>  typedef struct tag_xwt_widget
>  {
>     ULONG sign;
> 
>     // type is at disposal of drivers to interpret widget data correctly
>     int type;
> 
>     // pointer to raw widget data that is known by underlying driver
>     void *widget_data;
> 
>     // Destroys the underlying data.
>     BOOL (*destroy)( struct tag_xwt_widget *widget );
> 
>     // Sets a given property to a (variable type of) value
>     BOOL (*set_property)( struct tag_xwt_widget *widget, char *prop, void*
> pValue );
> 
>     // Send a group change; pValue is a hash of properties to be changed in
> one step
>     // useful to move, resize or reset the whole geometry.
>     // drivers must cache all the changes and apply them at once on the best
> function
>     BOOL (*set_pgroup)( struct tag_xwt_widget *widget, void* pValue );
> 
>     // retreive a single property of the underlying widget
>     BOOL (*get_property)( struct tag_xwt_widget *widget, char *prop, void*
> pValue );
> 
>     // creates a hash containing all the properties valid for this widget.
>     // properties are to be put in the PHB_ITEM pProps that is to be
> provided by the caller,
>     // the modules will receive it ready to accept properties
>     BOOL (*get_all_properties)( struct tag_xwt_widget *widget, void*
> pProps );
> 
>     void hbOwner; // shell holding the owner
>     void* pOwner; // commodity reference to the owner object
> 
>  } XWT_WIDGET, *PXWT_WIDGET;
> 
>  typedef struct tag_xwt_gtk_base
>  {
>     GtkWidget *main_widget;
>     GtkWidget * (*top_widget)( PXWT_WIDGET self );
>     int x;
>     int y;
>     int width;
>     int height;
>     int nId;
>  } XWT_GTK_BASE, *PXWT_GTK_BASE;
> 
> 
>  typedef struct tag_xwt_gtk_modal
>  {
>    INHERIT( XWT_GTK_BASE );
>    BOOL modal;
>    BOOL canceled;
>  } XWT_GTK_MODAL, *PXWT_GTK_MODAL;
> 
>  Compile properly on gcc 3.2.2

But with pedantic gcc 3.2.2 says:
xwt.c:71: warning: ISO C doesn't support unnamed structs/unions

>  but if i try to compile with gcc 3.3.x i got errors like
>  xwt_gtk.h:63: warning: declaration does not declare anything
>  xwt_gtk.h:71: warning: declaration does not declare anything
> 
>  Is unnamed structures  not more supported on gcc 3.3.x

unnamed structures are not part of ISO C. You must use
    '-fms-extensions' to enable them.

> 
>  how to correct the code to work with unnamed structures , or exist an
>  compiler switch to enable gcc 3.2 behavior
> 
>  Regards
>  Luiz