[Dwarf-discuss] Question about differentiate instruction address in different sections

[Ron Brender]

HaiFeng He wrote:
> Hi,
> 
> I'm a new learner of dwarf. In my current project, I'm trying to use dwarf
> information
> to link the instructions in a relocate binary to the corresponding source
> code line number.
> And I choose to use libdwarf to do that.
>...
 > are. The addresses listed there are actually the offset to the 
beginning of
> the code section,
> where the instructions locate. I can not find a way to differentiate whether
> an instruction is in .text or .text.init by looking at the address. Anybody
> can help me out?

I believe Jim Blandy has explained the "problem" correctly. A couple 
possible solutions:

1) Ask David Anderson to "fix" libdwarf...
2) Get an ELF dump of the same relocatable file. It should not be too 
hard to find the relocation that goes with the DWARF info and determine 
which text section is involved.
3) Try linking just the relocatable into an executable file--and ignore 
whatever unresolved symbols are reported. Then run libdwarf on the 
executable. Depending on the target OS, the relocations may have been 
incorporated into the DWARF info because the .text and .text.init 
sections get combined into a single program section. Then the code 
offset in the line info will be relative to that. You may need to look 
at a symbol definition or three to figure out the relative order of the 
section contributions, but it should be possible.

Good luck,
Ron