[Dwarf-Discuss] Some DWARFv5 draft feedback

Robinson, Paul paul.robinson at sony.com
Thu Dec 1 05:52:47 PST 2016


Thanks for reporting this stuff!  I see a few things you found have
already been reported, but please make sure to file issues for the
rest so we can clean up as much as we can.

> New FORMs. DW_FORM_ref_sup doesn't describe how the offset is
> represented. Currently the assumption in elfutils is that it is 4 or 8
> bytes depending on whether the containing unit is 32bit or 64bit DWARF.
> This would be consistent with DW_FORM_strp_sup. The consequence is that
> if the supplemental file has really big data sections you need a 64bit
> DWARF unit to reference everything in it.

Already filed as issue 161114.1.
http://dwarfstd.org/ShowIssue.php?issue=161114.1

> There is no description of the
> representation of DW_FORM_line_strp, but DW_FORM_strp is mentioned
> twice. I assumed the second should just be DW_FORM_line_strp.

Already reported to the editor as a typo, not filed as an issue.

> Macro Information Header. The macro information entries in the
> opcode_operands_table may be described in the table. But some cannot be
> described because some forms are not in the list of allowed forms. In
> particular DW_FORM_strp_sup is missing so DW_MACRO_define_sup and
> DW_MACRO_undef_sup cannot be described. And DW_FORM_ref_sup is missing,
> making it impossible to describe DW_MACRO_import_sup. Which makes the
> code that checks for allowed forms slightly inconvenient (it should
> reject these MACRO descriptions if those forms are used in the table,
> but not if they are defined implicitly). Also DW_FORM_line_strp isn't
> allowed. But it might be beneficial for describing files referenced by
> macros.

Good catch.  I see there is issue 161031.3 which has to do with allowed 
forms in the line table, but I'm not seeing one for the macro section.

Thanks,
--paulr



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