GDB utilities for rippled

This is an scripts to improve debugging the XRP Ledger in gdb on linux. It requires python 3.10 or better.

I built these for my own use, but I hope other XRP Ledger developers find these useful. I welcome improvements.

Key Features

The primary feature is a set of pretty printers. There are printers for:

• STAmount
• IOUAmount
• XRPAmount
• Issue
• Buffer
• STObject (and derived classes)
• STBitString
• STAccount
• STInteger
• STBase
• STVar
• SField
• BaseUInt (including special printers for AccountID and Currency)
• JsonValue

There is also special support known accounts - this is useful when debugging unit tests and when replaying transactions. For example, in unit tests, the account "rG1QQv2nh2gr7RCZ1P8YYcBUKCCN633jCn" is always "alice". The pretty printer will display "alice" when it sees that account (or any of the other well-known accounts).

As an example for what these scripts do, here's an example of how gdb would display a ledger object without the pretty printer:

  members of ripple::STObject:
    v_ = {
      <std::_Vector_base<ripple::detail::STVar, std::allocator<ripple::detail::STVar> >> = {
        _M_impl = {
          <std::allocator<ripple::detail::STVar>> = {
            <std::__new_allocator<ripple::detail::STVar>> = {<No data fields>}, <No data fields>}, 
          <std::_Vector_base<ripple::detail::STVar, std::allocator<ripple::detail::STVar> >::_Vector_impl_data> = {
            _M_start = 0x7fffdc04c3b0,
            _M_finish = 0x7fffdc04cbf0,
            _M_end_of_storage = 0x7fffdc04cbf0
          }, <No data fields>}
      }, <No data fields>},
    mType = 0x555562f77428
  }, 
  <ripple::CountedObject<ripple::STLedgerEntry>> = {<No data fields>}, 
  members of ripple::STLedgerEntry:
  key_ = {
    data_ = {
      _M_elems = {851601963, 3830140074, 614331419, 55245401, 1135993159, 3459238308, 35422944, 2833900033}
    }
  },
  type_ = ripple::ltACCOUNT_ROOT

Here's the same ledger object with the pretty printer (notice the "Account" is "master", not "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh", since this is a well-known account):

$13 = (std::__shared_ptr_access<ripple::STLedgerEntry, (__gnu_cxx::_Lock_policy)2, false, false>::element_type &) @0x7fffdc0880f0: {
  <ripple::STObject> = {
  "Account": "master",
  "Sequence": 3,
  "Balance": "99999989999.999970/XRP/RootAccount",
  "OwnerCount": 0,
  "PreviousTxnID": "(ripple::base_uint<256, void>) 3077E7D79E2814543A19322FADC2E4B21FD90846B1C1F5D0B736094FCFE40557",
  "PreviousTxnLgrSeq": 3,
  "LedgerEntryType": 97,
  "Flags": 0
}, 
  <ripple::CountedObject<ripple::STLedgerEntry>> = {<No data fields>}, 
  members of ripple::STLedgerEntry:
  key_ = (ripple::base_uint<256, void>) 2B6AC232AA4C4BE41BF49D2459FA4A0347E1B543A4C92FCEE0821C0201E2E9A8,
  type_ = ripple::ltACCOUNT_ROOT
}

Installation

In the .gdbinit files, add a section for python, and make sure the gdb pretty printers are on the sys path, and then add the directory where this project lives to the path. For example:

python

import platform
import os
import sys
from os.path import expanduser

home = expanduser('~')

if os.path.isdir('/usr/share/gcc-12.2.0/python'):
    sys.path.insert(0, '/usr/share/gcc-12.2.0/python')
    from libstdcxx.v6.printers import register_libstdcxx_printers
    register_libstdcxx_printers (None)

sys.path.insert(0, home + '/apps/gdb_python')
from rippled.pretty_printers.printers import register_rippled_printers
register_rippled_printers(None)

end

Of course, replace home + '/apps/gdb_python' with the location of this project and /usr/share/gcc-12.2.0/python with the location of the gcc pretty printers on your system.