gdb-tools

This repository contains various tools used to make the time spent in gdb more comfortable.

To install these tools, first install the modules with

pip install gdb-tools

or with easy_install or python setup.py install [--user].

Then you need to import corresponding modules into your gdb. Add, for example,

py import duel

into your ~/.gdbinit. If you plan to use pretty_printer module, I'd recommend to put all your python gdb enhancements in ~/.gdb.py and source it from ~/.gdbinit.

pretty_printer.py

A convenience helper to write gdb pretty-printers. Import this module and write new pretty printers as easy as

from pretty_printer import PrettyPrinter

@PrettyPrinter
def st_bitmap(val):
    s=''
    for i in range((val['n_bits']+31)//32):
        s = format(int(val['bitmap'][i]), '032b') + s
    return "b'" + s[-int(val['n_bits']):] + "'"

Here val is a gdb.Value object to print, and st_bitmap is the type to pretty-print (alternatively, a type can be passed to the decorator as an argument, useful for types that aren't valid Python identifiers). If the type has a name, either typedef'ed name or the underlying actual type can be used in the pretty printer definition (useful, for types like typedef int set_of_flags). Pointers are resolved automatically:

(gdb) p map
$1 = b'001010111'
(gdb) p &map
$1 = (st_bitmap *) 0x7fff8610 b'001010111'

Import this module into your ~/.gdb.py and create your own pretty printers there.

DUEL — Debugging U (might) Even Like

A high level language for exploring various data structures. Created by Michael Golan in 1993, who implemented it for gdb 4.x. "Insanely cool", according to gdb developers. This is DUEL.py — a pure python implementation that uses gdb Python API and the Arpeggio parser. Install arpeggio (or copy it into duel/ — it's only 20K) and import duel into your ~/.gdb.py. Few examples of what DUEL can do:

Command	Explanation
`dl ?`	short help
`dl x[10..20,22,24,40..60]`	display `x[i]` for the selected indexes
`dl x[9..0]`	display `x[i]` backwards
`dl x[..100] >? 5 <? 10`	display `x[i]` if `5<x[i]<10`
`dl val[..50].(is_dx ? x : y)`	`val[i].x` or `val[i].y` depending on `val[i].is_dx`
`dl x[i:=..100] >? x[i+1]`	check whether `x[i]` is sorted
`dl (x[..100] >? 0)[[2]]`	return the 3rd positive `x[i]`
`dl argv[0..]@0`	`argv[0]`, `argv[1]`, etc until first null
`dl emp[0..]@(code==0)`	`emp[0]`, `emp[1]`, etc until `emp[n].code==0`
`dl head-->next->val`	`val` of each element in a linked list
`dl head-->(left,right)->val`	`val` of each element in a binary tree
`dl head-->next[[20]]`	element 20 of list
`dl #/head-->next`	count elements on a linked list
`dl #/(head-->next-val>?5)`	count those over 5
`dl head-->(next!=?head)`	expand cyclic linked list

Or read the manual.

an3l/gdb-tools

gdb-tools

pretty_printer.py

DUEL — Debugging U (might) Even Like