Re: Simple struct member offset doesn't need a full dwarf location expression

[Richard Henderson <rth at redhat dot com>]

On 07/07/2009 10:09 AM, Mark Wielaard wrote:
> Hi,
>
> As explained in PR40659 a simple struct member offset doesn't need a
> full dwarf location expression, but can just encode the
> DW_AT_data_member_location as a constant offset according to the Dwarf
> standard. This saves a little space (one byte per struct field member)
> and is slightly simpler to handle for debuginfo consumers. It is also
> the recommended way to encode this according to the examples in the
> Dwarf standard appendix.

This is true for dwarf3 only.

For dwarf2, section 7.5.4 figure 18 specifies that DW_AT_d_m_l is only 
valid with block/reference forms.  Which suggests we want to emit this 
only when dwarf_version > 2.


r~