[GSoC 2024] Improving the Userland Debugging Experience

Introduction

Hello again! I am Trung Nguyen (a.k.a @trungnt2910). You might have already known me as the maintainer of the .NET 8 Port for Haiku since last year’s GSoC program.

I am delighted to be accepted into GSoC again! This year, under the guidance of @waddlesplash - one of the experienced Haiku devs that I admire the most, I will work on one of the core issues of software development on Haiku: the debugging experience.

Project overview

Currently, the native Debugger app is the only known working tool for local userland debugging on Haiku. However, this tool has various bugs and limitations, hindering the process of building complex applications, especially ports.

Moreover, for many developers working with a UNIX-like environment, the most familiar debugger would be either GDB or LLDB. These two programs also come with lots of features that are not present in Debugger, such as Python scripting. The debuggers (along with some library components they provide) are also the building blocks of IDEs and other developer tools.

Providing an alternative debugger choice would also speed up the process of fixing Debugger bugs, especially cases when Debugger crashes when trying to debug itself.

Previous attempts have been made to bring GDB and LLDB to Haiku, neither of which has produced working debuggers.

For GSoC 2024, I aim to bring a modern debugger for the first time to x86_64 Haiku. Using the tools I build and the knowledge I learn, I will go on to improve Haiku’s native Debugger and the infrastructure surrounding it.

Goals

Porting GDB

I will first start by examining the existing GDB 8.1 port. If some small bugs get uncovered, I will spend a bit of time trying to fix them and see if gdb could launch and debug programs.

Most of the time though, I will focus on creating a new fork of GDB 14. Starting a new port from scratch has proven to be effective in my last project by allowing me to have a fresh look at the codebase and freeing me from potential long-standing bugs. Furthermore, the internal GDB interface has significantly changed, moving from C to C++, requiring major refactorings if the current patchset is to be reused.

Fixing Debugger issues

With a stable GDB, I will go on to fix Debugger issues. For this phase, I will prioritize those that has greatly affected my past experience (#8877, #11596, and #15087), as well as those with more interest from the community depending on the time available.

Porting LLDB

LLDB, unlike most other tools in the LLVM project, provides a completly different debugging interface compared to its GNU counterpart. Some tools also depend specifically on LLDB. Therefore, along with Haiku’s native Debugger improvements, I will also work on a port of LLDB 18.

Updates

Like the previous years, a real-time overview of my work can be found on my GitHub profile on the “Contribution activity” section.

I will also start technical discussions on the #haiku IRC channel.

When progress is made that might interest users, I will post an update on this forum thread.

This blog will also be updated once a month with the project’s progress, challenges faced, and some insights on the undocumented Haiku Debugger API. Previews of my upcoming blog posts may also be available on my Reality blog.

Conclusion

Once again, I would like to express my gratitude for the continued trust and support from Haiku and everyone from the community during the last two years. I wish to have another productive coding adventure this year!