Re: DW_TAG_imported_declaration DW_TAG_base_type w/o DW_AT_name [Re: using directive patch]

[Sami Wagiaalla <swagiaal at redhat dot com>]

Jan Kratochvil wrote:
> On Sun, 07 Sep 2008 20:36:12 +0200, Jan Kratochvil wrote:
> > +/* Read the import statement specified by the given die and record it.  */ 
> > +
> > +static void
> > +read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
> > +{
> ...
> > +  import_attr = dwarf2_attr (die, DW_AT_import, cu);
> ...
> > +  imported_die = follow_die_ref (die, import_attr, &cu);
> > +  imported_name = dwarf2_name (imported_die, cu);
> > +  if (imported_name == NULL)
> > +    {
> > +      /* C++ imports from std:: DW_TAG_base_type with no DW_AT_name - why?  */
> > +      return;
> > +    }

> (2) DW_TAG_imported_declaration -> DW_TAG_base_type with no DW_AT_name:
>
>  <1><46>: Abbrev Number: 4 (DW_TAG_namespace)
>     <47>   DW_AT_name        : std      
>  <2><51>: Abbrev Number: 5 (DW_TAG_imported_declaration)
>     <54>   DW_AT_import      : <0x50e>  [Abbrev Number: 24 (DW_TAG_base_type)]
>  <1><50e>: Abbrev Number: 24 (DW_TAG_base_type)
>     <50f>   DW_AT_byte_size   : 8       
>     <510>   DW_AT_encoding    : 5       (signed)
>
>     I do not see a meaning of such import - if it has no name.  But this bug
>     may be already covered by PR debug/14168 or possibly by PR debug/14169.

Is this a bug though. This imports the type specified by 0x50e keeping its
name in the current context.

like here:

namespace A{
  class B{
  public:
    int	x;
  };
}

int main(){
  using A::B;
  B b;
  return 0;
}

...
 <2><7b>: Abbrev Number: 8 (DW_TAG_imported_declaration)
    <7c>   DW_AT_decl_file   : 1
    <7d>   DW_AT_decl_line   : 9
    <7e>   DW_AT_import      : <0x3b>   [Abbrev Number: 4 (DW_TAG_class_type)]
...