Pete Warden petewarden

GDB Tips and Tricks for Debugging Pintos

As I get more familiar with the Pintos environment, I want to save notes on techniques I've found improved my quality of life when debugging through the assignments. Please don't add any comments that discuss project solutions, but feel free to contribute your own favorite ways of improving the debugging process, since I'm hoping we can create a trail of breadcrumbs for future students.

Save GDB Command History Between Sessions

One of the first things I like to do is ensure I can use the up arrow to access commands from a previous gdb session, since debugging tends to involve a lot of repetition!

	#!/usr/bin/env python

	import os
	import struct
	import sys

	# adapted from: http://stackoverflow.com/a/495305/1338797 and
	# https://github.com/tgandor/meats/blob/master/missing/arch_of.py

	def arch_of(dll_file):

	# I use VS Code for Pintos development on Stanford's myth servers, but sometimes it fails to connect
	# and can be hard to reset. Normally I'd delete `~/.vscode-server` on the remote machine, but the
	# networked file system used at Stanford often seems to leave files open semi-permanently even after
	# an SSH session has completed, so if I run `rm -rf ~/.vscode-server` I see errors like:

	$ rm -rf .vscode-server
	rm: cannot remove '.vscode-server/cli/servers/Stable-903b1e9d8990623e3d7da1df3d33db3e42d80eda/server/bin': Directory not empty
	rm: cannot remove '.vscode-server/extensions/ms-vscode.cpptools-1.18.5-linux-x64.-5974b6c6.vsctmp/bin/.__afsC4E7': Device or resource busy

	# To solve this, I've taken to using the `lsof` command to figure out which processes have those

	#ifndef INCLUDE_TRACE_H
	#define INCLUDE_TRACE_H

	#include <stdio.h>
	#include <stdint.h>

	#define TRACE_STR(variable) do { fprintf(stderr, __FILE__":%d "#variable"=%s\n", __LINE__, variable); } while (0)
	#define TRACE_INT(variable) do { fprintf(stderr, __FILE__":%d "#variable"=%d\n", __LINE__, variable); } while (0)
	#define TRACE_PTR(variable) do { fprintf(stderr, __FILE__":%d "#variable"=0x%016lx\n", __LINE__, (uint64_t)(variable)); } while (0)
	#define TRACE_SIZ(variable) do { fprintf(stderr, __FILE__":%d "#variable"=%zu\n", __LINE__, variable); } while (0)

	# By Pete Warden, @petewarden
	# To use this, open ~/.bashrc in your editor of choice,
	# and place these settings at the end.
	# Based on https://unix.stackexchange.com/a/48113 and
	# https://blog.sanctum.geek.nz/better-bash-history/

	# Ignore both duplicate commands, and those that start with a space.
	HISTCONTROL=ignoreboth

	# Append to the history file, don't overwrite it.

	# ==============================================================================
	"""LSTM quantization with python."""

	from __future__ import absolute_import
	from __future__ import division
	from __future__ import print_function

	import pathlib

	from absl import app

	import re
	output_data = bytearray()
	with open('tensorflow/tensorflow/lite/micro/examples/magic_wand/magic_wand_model_data.cc', 'r') as file:
	for line in file:
	values_match = re.match(r"\W(0x[0-9a-fA-F,x ]+).", line)
	if values_match:
	list_text = values_match.group(1)
	values_text = filter(None, list_text.split(","))
	values = [int(x, base=16) for x in values_text]
	output_data.extend(values)

	/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,

	def StripTfliteFile(tflite_input, tflite_output):
	"""Given 'tflite_input`, write stripped version, 'tflite_output'."""
	if not os.path.exists(tflite_input):
	raise RuntimeError("Invalid filename %r" % tflite_input)
	with open(tflite_input, "rb") as file_handle:
	file_data = bytearray(file_handle.read())
	model_obj = schema_fb.Model.GetRootAsModel(file_data, 0)
	model = schema_fb.ModelT.InitFromObj(model_obj)
	model.description = ""
	for subgraph in model.subgraphs:

	# To convert from .ogg files to .wavs:
	# find . -iname "*.ogg" -print0 \| xargs -0 basename -s .ogg \| xargs -I {} ffmpeg -i {}.ogg -ar 16000 ../converted_early_wavs/{}.wav
	# Then run the extract_loudest xcode project to get one-second clips.

	import glob
	import os
	import re
	import shutil

	data_index = {}