Print C++ STL Containers With GDB

1. Introduction

Looking at C++ STL containers in GDB can be confusing - they’re full of internal details. With libstdc++’s Python pretty printers, GDB can show these containers in a much cleaner way. This guide will show you how to set them up and use them to make debugging easier.

2. Setup stdc++ Python Pretty Printers

Check if libstdc++ python available.

  
$ ls /usr/share/gcc/python/libstdcxx/

If not available, clone gcc source code.

  
$ wget https://github.com/gcc-mirror/gcc/archive/refs/heads/master.zip -O gcc.zip
$ unzip gcc.zip

Edit ~/.gdbinit to add libstdc++ python to sys.path.

  
python
import sys
sys.path.insert(0, '/root/gcc-master/libstdc++-v3/python/libstdcxx')
from libstdcxx.v6.printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end

Check if libstdc++ pretty-printer added successfully.

  
$ gdb -batch -ex 'info pretty-printer'
  
  
global pretty-printers:
  builtin
    mpx_bound128
  libstdc++-v6

References