Modules and debugging in DWARF

[Iain Buclaw]

On 22 February 2014 18:15, Sarath Kodali <sarath at dummy.com> wrote:
> On Saturday, 22 February 2014 at 00:30:18 UTC, Iain Buclaw wrote:
>>
>> Hi all,
>>
> [skip]
>
>>
>> And currently I'm testing selective imports to be represented as
>> DW_TAG_imported_declaration.  Don't have any examples for yet, but it looks
>> like it would be the imported declaration tag pointing to the real
>> declaration.
>>
>>
>> Regards
>> Iain.
>
>
> Below is dwarf info generated by g++ for selective imports in C++
> code.
>
> < 1><0x00000045>    DW_TAG_typedef
>                         DW_AT_name                  va_list
>                         DW_AT_decl_file             0x00000002
> /usr/lib/gcc/i586-suse-linux/4.7/include/stdarg.h
>                         DW_AT_decl_line             0x00000066
>                         DW_AT_type                  <0x00000029>
> < 1><0x00000050>    DW_TAG_namespace
>                         DW_AT_name                  std
>                         DW_AT_decl_file             0x00000004
> /home/sarath/development/dbg/tests/c/<built-in>
>                         DW_AT_decl_line             0x00000000
>                         DW_AT_sibling               <0x00000079>
> < 2><0x0000005b>      DW_TAG_imported_declaration
>                           DW_AT_decl_file             0x00000005
> /usr/include/c++/4.7/cstdarg
>                           DW_AT_decl_line             0x00000038
>                           DW_AT_import                <0x00000045>
>
> - Sarath

Yeah, I don't need to know that per say (although I will have to bear
in mind how GDB represents it in its runtime environment).  GCC
provides a handy debug hooks called 'imported_module_or_decl'.  I just
need to make sure that the trees passed to it are generated correctly.
:-)

I just posted this information because this is what gdc does today,
and at least DMD developers have the misfortune for having to have to
worry about this.  :o)

Regards
Iain.