gdb-tools 1.5

Various tools to improve the gdb experience

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

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.