[Dwarf-Discuss] find local variable information from the dwarf
Neeraj kushwaha
kushneeraj@gmail.com
Tue Jan 22 01:38:39 GMT 2008
Thanks for the reply.
But how to interpret these lines
>* DW_AT_frame_base [
*>* 0]<lowpc=0x24><highpc=0x28>DW_OP_breg4+4
*>* [ 1]<lowpc=0x28><highpc=0x2e>DW_OP_reg1
*>* [ 2]<lowpc=0x2e><highpc=0x2f>DW_OP_breg4+4
*>* [ 3]<lowpc=0x2f><highpc=0x31>DW_OP_breg4+8
*>* [ 4]<lowpc=0x31><highpc=0x56>DW_OP_breg5+8
*
Please explain briefly.
Regards
Neeraj
On Jan 22, 2008 12:50 AM, David Anderson <davea42 at earthlink.net> wrote:
> Neeraj kushwaha wrote:
> > Hi All,
> >
> > I am trying to find the location and value of local variable in a stack
> > frame from the core dump.
> > As GDB can fetch the value and location of local variable using the
> > information from the dwarf debugging format.
> >
> > I am trying to manually find the location and value of the local
> variable
> > from the core.
> >
> > This is what i did; from the a.out, I extracted the dwarf information
> using
> > "dwarfdump -a a.out"
> >
> > and using the GDB i am trying to print the dump from the core "x/88b
> main1"
> >
> > But I am not able to find the location information of the local variable
> >
> > for example:
> >
> > DW_AT_name c
> > DW_AT_decl_file 1 /home/neeraj/4.c
> > DW_AT_decl_line 15
> > DW_AT_type <177>
> > DW_AT_location DW_OP_fbreg -20
> >
> >
> > local variable is at location DW_OP_fbreg - 20. But how to find the
> > DW_OP_fbreg?
> >
> >
>
> Look back a few lines. The fbreg is defined in the subprogram
> DIE (DW_AT_frame_base):
>
> > <1>< 315> DW_TAG_subprogram
> > DW_AT_external yes(1)
> > DW_AT_name main
> > DW_AT_decl_file 1 /home/neeraj/4.c
> > DW_AT_decl_line 14
> > DW_AT_type <177>
> > DW_AT_low_pc 0x8048398
> > DW_AT_high_pc 0x80483ca
> > DW_AT_frame_base [
> > 0]<lowpc=0x24><highpc=0x28>DW_OP_breg4+4
> > [ 1]<lowpc=0x28><highpc=0x2e>DW_OP_reg1
> > [ 2]<lowpc=0x2e><highpc=0x2f>DW_OP_breg4+4
> > [ 3]<lowpc=0x2f><highpc=0x31>DW_OP_breg4+8
> > [ 4]<lowpc=0x31><highpc=0x56>DW_OP_breg5+8
> >
>
> Hope that helps.
> David Anderson.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.dwarfstd.org/private.cgi/dwarf-discuss-dwarfstd.org/attachments/20080122/a30feedf/attachment.htm>
More information about the Dwarf-discuss
mailing list