[fpc-devel] dvarf 3 implementation issue

[Jonas Maebe]

On 08/05/14 16:10, Martin Frb wrote:
> Indeed there is a workaround that can be applied, but it would mean
> extra slowdown, as additional ptype must first be sent to gdb to find
> out, if it an dynarray = otherdyn.

I understand it's annoying, but I don't see a good solution.

> On the other hand, gdb is not yet dwarf3 ready, and if dwarf3 means that
> much extra maintenance, I may just not support it via gdb.

Actually, gdb even already supports most of DWARFv4 (and gcc generates 
it too). variable-length-array support was only merged to gdb 
master/trunk recently though, which is required for this FPC dynamic 
array support in the debugging information.

> Well at this time, it is not clear, if it actually would be added to the
> gdb based version at all, even if all was fixed. It is just keeping an
> option open.
>
> --------
> What is the advantage for fpc to use DW_AT_data_location for dyn array?

It's to be able to describe dynamic arrays as actual arrays instead of 
as pointers in the debug information, so that debuggers don't have to 
know about FPC internals to determine that these pointers are actually 
arrays and to find out what their length is..


Jonas