Re: Hotpatch construction and __LINE__

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 12/08/15 09:09, Jan Beulich wrote:
>>>> On 05.08.15 at 15:25, <andrew.cooper3@citrix.com> wrote:
>> Jan had a plan to make Xen read its own DWARF symbol table rather than
>> using the current cludge we have where we partially link Xen, extract
>> the public symbol table, rewrite symbol-offsets.c and relink it onto the
>> end.
> Either I mis-expressed this, or you mis-remember: I'm in no way
> intending to use DWARF information. What I want to use is the
> _full_ ELF / COFF symbol table instead of nm output (which has
> quite a bit of interesting information discarded).

I misremembered.  Sorry.

>
>> Perhaps there is an opportunity to piggy-back onto that and have all
>> file/line references coming from the DWARF information.  I suspect this
>> will be similar to what Linux does, as it already has support for using
>> its own DWARF/STABS information.
> I'm curious where you found this as I'm unaware of such
> functionality.

The x86 linker script includes the information (given appropriate
CONFIG_ options), and the perf subsystem appears to have code to
interpret itself.

~Andrew

> Recently they even decided to discard all
> .eh_frame / .dwarf_frame generating annotations the
> compiler can't itself generate.
>
> Jan
>