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2337

answers:

4

Any recommendations for a good cross-platform library for reading ELF file debug information in DWARF format? I'd like to read the DWARF debug info in a Python program.

+2  A: 

The concept of "ELF debug info" doesn't really exist: the ELF specification leaves the content of the .debug section deliberately unspecified.

Common debug formats are STAB and DWARF. A library to read DWARF is libdwarf.

Martin v. Löwis
Yes, quite right. DWARF is what I'm interested in.
Craig McQueen
I updated the question accordingly.
Craig McQueen
Is libdwarf cross-platform, do you know? The page doesn't say, but seems to have an overall Unix flavour to it.
Craig McQueen
I haven't tried porting it. It seems that it has some Unix specificisms in it (e.g. in the darfdump executable); it's also based on libelf. However, porting it to a different system should be straight-forward.
Martin v. Löwis
I've done some minor work with libdwarf. It's dependencies outside of the C standard library is libelf, which is currently available for Windows. It should be a fairly (for some definition of "fairly") easy task to compile it for Windows in Cygwin.
Falaina
I successfully ported libdwarf to compile on windows with visual studio 2008.
Torleif
@Torleif hi, since you've ported libdwarf successfully can you take a look at my post and give me some pointers?http://stackoverflow.com/questions/3581931/trying-to-compile-libdwarf-gives-undefined-errors
Victor T.
+2  A: 

You might find useful informations here:

Nick D
Thanks, I missed that other SO question, I guess because I wasn't searching for "DWARF". I'll update the title of this question.
Craig McQueen
+1  A: 

Your options for reading the DWARF debugging information are unfortunately quite limited.

As far as I know there is only one general purpose library for parsing DWARF debugging information and that is link text. Unfortunately no one has written Python bindings for libdwarf (maybe you could take it up upon yourself and share it with everyone else :) ) You could certainly attempt to access the library's functions using ctypes or the Python C API.

A much less elegant solution, however, is to use an existing DWARF parser and parse the textual information it outputs. Your options for this (on Linux) are

objdump -W
readelf --debug-dump=[OPTIONS]

I currently use a project that builds off of readelf and it's support for the DWARF debugging information is very full featured. You could simply use Python to execute either command in the shell and then parse the information as you need. Certainly not as ideal as a library, but should do the trick.

EDIT: I noticed in a previous comment you mentioned Windows. Both of these programs(objdump and readelf) are part of GNU-binutils, so they should be available with Cygwin or mingw.

Falaina
+1  A: 

You might be interested in the DWARF library from pydevtools:

>>> from devtools.dwarf import DWARF
>>> dwarf = DWARF('test/test')
>>> dwarf.get_loc_by_addr(0x8048475)
('/home/emilmont/Workspace/dbg/test/main.c', 36, 0)
>>> print dwarf
.debug_info
COMPILE_UNIT<header overall offset = 0>
<0><11> compile_unit
producer: GNU C 4.4.3
language: C89
name: a/test.c
comp_dir: /home/emilmont/Workspace/dbg/test
low_pc: 0x080483e4
high_pc: 0x08048410
stmt_list: 0
[...]
emilmont
That's great to know. Couple of questions: 1) What platforms are supported (Windows, Linux)? 2) Can you put it on the [PyPI](http://pypi.python.org/pypi)?
Craig McQueen