Add source context where available

[bnagy]

I love the gef commands, but when I have source I'd like to be able to see it...

gdb-dashboard shows source and asm if possible, just asm if not: https://github.com/cyrus-and/gdb-dashboard/blob/master/.gdbinit#L678-L752 which would be ideal...

[hugsy]

That's a pretty good idea. Will add that.

Thanks!

[hugsy]

It should be working as expected. Let me know if you find bugs.

[hugsy]

Confirmed works on x86, ARM, PowerPC for gdb > 7.9 (for gdb.find_pc_line())

[bnagy]

By >7.9 you mean it only works on 7.10? I re-enabled the exception printing and I get:

[!] in `context_source, exception raised: 'utf-8' codec can't decode byte 0xa9 in position 96: invalid start byte

ben@shitweasel:~/src/jxrlib$ gdb -version
GNU gdb (Ubuntu 7.9-1ubuntu1) 7.9

[hugsy]

Which version of python are you using inside gdb ?

[bnagy]

I don't know how to check that. System python is 2.7 but I thought gdb always links against 3 now? I'll google tomorrow :P

[bsmt]

Open a python shell in gdb ("pi" command), then

import sys
sys.version

[hugsy]

@bnagy $ gdb -nx -ex 'python print (sys.version)' -ex quit

[bnagy]

'3.4.3 (default, Mar 26 2015, 22:07:14) \n[GCC 4.9.2]'

[hugsy]

I've setup an Ubuntu 14.04 with gdb 7.7 and python 3.4, could get your error triggered again.

Is it happening against all your bins ? Or just one ?

[bnagy]

It's just one, by the looks - AND the source file happens to have a non-utf-8 character in the source file, so that sounds like a good chance to be the problem. I tried a quick guess from @bsmt using return buf.decode("utf-8", "ignore") in read_string but that didn't work - maybe I missed something or that's the wrong place to try and ignore bad UTF-8.....

[hugsy]

Do you have a sample somewhere I can download so I try to reproduce locally ?

[bnagy]

Can't really, with this one... you should be able to put any non utf-8 char in the source though like from http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt

For now, I think I can run the codebase through iconv, which solves my immediate issue as per http://superuser.com/a/49147 (which is a possible workaround for anyone else with the issue, but hopefully it's easy to fix ;)

[hugsy]

Have you tried changing the charset (https://sourceware.org/gdb/onlinedocs/gdb/Character-Sets.html#Character-Sets) ? (set target-charset in gdb)

[bnagy]

I tried set target-charset WINDOWS-1252 with no luck. Fixing the source files via iconv still works. If you can't work out a way to clean / change the encoding in the plugin then it's probably OK to close this issue, or just open a new one for the encoding problem (since the enhancement is complete)

Thanks again for the tool :)

PS: Inplace fixing didn't seem to work for me. This script does.

#! /bin/sh

find . -name '*.c' -exec iconv --verbose -f windows-1252 -t utf-8 -o {}.fix {} \;
find . -name "*.c" -delete
find . -name "*.c.fix" -exec rename 's/\.fix$//' {} \;

[hugsy]

I haven't been able to find a clean so I guess I will do as you suggest and close the ticket keeping in mind your little script in case this issue happens again in the future.

Thanks for the feedbacks, always appreciated :)