GSoC'11: DWARF2 call frame information
panxingxing at mprc.pku.edu.cn
Sun Mar 20 15:24:23 UTC 2011
2011/3/20 Chagin Dmitry <dchagin at freebsd.org>:
> On Sun, Mar 20, 2011 at 11:08:10AM +0800, Xingxing Pan wrote:
>> 2011/3/20 Chagin Dmitry <dchagin at freebsd.org>:
>> > On Sun, Mar 20, 2011 at 12:36:39AM +0800, Xingxing Pan wrote:
>> >> Hi, everyone.
>> >> I'm a student interested in the project "DWARF2 call frame
>> >> information" for Summer of Code 2011.
>> >> I'd like to know which compiler I will work on to add DWARF2 support.
>> >> This project is not tagged by "suggested". Will it be ok to choose it
>> >> as the target?
>> > hi Xingxing,
>> > You should carefully reread the proposed idea. Especially in the
>> > "A debug kernel is not able to show stack traces with cross
>> > exceptions anymore. This is because we do not emit any dwarf2
>> > call frame information for any assembler code, since gdb switched
>> > to the dwarf2 format" part.
>> > And, of course, this work is very important for the community. So, IMO,
>> > it will be ok as the target :)
>> > Thank you.
>> > --
>> > Have fun!
>> > chd
>> Hi chd,
>> Thank you for your reply. I thought the dwarf2 call frame information
>> was generated by the toolchain.
> mostly yes. but not in the assembler code written by hand.
>> That's why I care about the states of the compiler.
>> I'm not quite understand the proposed idea. Could you show me more
>> details of the project?
>> I really appreciate your support.
> hm, you should add the .cfi directive in each .S file by hand:
> Have fun!
Thanks for your reply. I think I have got the idea.
For the object files generated by the toolchain, there's no need to worry about
DWARF call frame information if the DWARF is supported by the toolchain.But
the assembly written by hand is an exception.
Different architecture has different assembly. That means I have to add DWARF
for all these architectures currently supported by FreeBSD. Maybe I need a
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