.debug_line section

[mcheung63]

Hi, what these three numbers mean in .debug_line section in ELF file?



thanks
from Peter

[Owen]

Exactly what they say? I presume you begin at the start of the section and read it as a sort of bytecode.

Oh, and you're running as root?!

[mcheung63]

ok, i understand them now

[neon]

On an unrelated topic, whats up with the posting of huge images on forums? like this 1440x900 one? Id at least scale it down or something...

[Brynet-Inc]

Oh, and you're running as root?!

I think he's already been outed on this one a few times, he seems to avoid/ignore the issue.. kind of sad really.

[Owen]

Oh, and you're running as root?!

I think he's already been outed on this one a few times, he seems to avoid/ignore the issue.. kind of sad really.

Well, if he insists on running Linux like you would run Windows 9x... it's his choice.

[JamesM]

Check the DWARF format that I linked you to. The debug_* sections use an special automaton to create the debug information (instead of storing it in a great big table). The lines you mentioned are detailing what that automaton is doing (advancing the line pointer, from one value to another).

[mcheung63]

Thank you so much James.
The automation is too complex for me. I am rewriting the dwarf.c from binutils to java, so peter-bochs can support single step trace in C level. Wherever you loaded the ELF (kernel/app), bochs can single step trace on it. I think it is a great feature for os developer.
thanks
from Peter

[JamesM]

Thank you so much James.
The automation is too complex for me. I am rewriting the dwarf.c from binutils to java, so peter-bochs can support single step trace in C level. Wherever you loaded the ELF (kernel/app), bochs can single step trace on it. I think it is a great feature for os developer.
thanks
from Peter

You won't manage that without grasping the concept of the automaton, because it's central to the DWARF standard!

[mcheung63]

Hi All
I rewrite the "-wL" part of binutil 2.20 into Java. http://code.google.com/p/peter-bochs/so ... fUtil.java
It can read the debug line information from an ELF file.

I need to make bochs able to disassemble in any memory location, then peter-bochs can support c level single step trace. Very helpful to debug my os app

thanks
from Peter

[JamesM]

http://code.google.com/p/peter-bochs/source/browse/trunk/peter-bochs-debugger/src/peter/elf/ElfUtil.java

Ewwwwwww. That is all.

[AndrewAPrice]

http://code.google.com/p/peter-bochs/source/browse/trunk/peter-bochs-debugger/src/peter/elf/ElfUtil.java

Ewwwwwww. That is all.

That's not so bad. Try porting a compiler to a new architecture, and you have reference code that you know does something important but you have no clue how it does it because of obscure variable names and macros so you're really trusting that it work and you see:

Code: Select all

OBFUSTICATEDMESSOBFUSTICATEDMESSOBFU
STICATEDMESSOBFUSTICATEDMESSOBFUSTICA
TEDMESS/*FIX ME*/OBFUSTICATEDMESSOBFUS
TICATEDMESSOBFUSTICATEDMESS