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AlexDenisov

750 karma · joined March 22, 2013

Sometimes I talk to machines, but more often machines talk to me.

Compilers, LLVM, Mutation Testing, Software Hardening.

alex@lowlevelbits.org

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AlexDenisov··on Ask HN: What are you working on? (February 2026)
Building a tool for finding scientific papers behind real-world OSS projects: https://papergrep.dev/

This is a follow up to an idea I had years ago https://news.ycombinator.com/item?id=13022649, which is now semi-automated (with lots of manual curation as the last step).

The biggest challenges:

- how to organize all this info in a nice way

- where to find more time to read all the gems I've found so far :)

UPD: formatting

AlexDenisov··on Optimization Techniques for GPU Programming [pdf]
There are also video lectures which are almost 1-1 mapping of the book

Programming Massively Parallel Processors: https://www.youtube.com/watch?v=4pkbXmE4POc&list=PLRRuQYjFhp...

AlexDenisov··on Ask HN: Favourite open source game?
> A retro multiplayer shooter

> Teeworlds is a free online multiplayer game, available for all major operating systems. Battle with up to 16 players in a variety of game modes, including Team Deathmatch and Capture The Flag. You can even design your own maps!

https://www.teeworlds.com

AlexDenisov··on Snowman native code to C/C++ decompiler for x86/x86_64/ARM
Here is a talk by Dr. Yegor Derevenets about this project https://www.youtube.com/watch?v=f_0EF2BqeQ4
AlexDenisov··on How the GNU coreutils are tested
I have a "series" of articles from a few years ago covering FreeBSD, LLVM, and GNU Make (https://lowlevelbits.org/categories/system-under-test/) and even created a separate website with a few more articles https://systemundertest.org, but stopped later.
AlexDenisov··on How the GNU coreutils are tested
I started building exactly this some years ago, but eventually stopped for some reason https://systemundertest.org
AlexDenisov··on Mutation Driven Testing: When TDD Just Isn’t Good Enough
re: absence of C++ tools

Have you looked at Mull[1] or Dextool[2]?

[1] https://github.com/mull-project/mull

[2] https://github.com/joakim-brannstrom/dextool/tree/master/plu...

AlexDenisov··on Ask HN: Show me your half baked project
Not really half-baked, but not ready for the prime time either:

Mull[0] is a tool for mutation testing of C and C++ projects. The goal of mutation testing is to show the gaps in the semantic coverage

[0] https://github.com/mull-project/mull

AlexDenisov··on Mutation testing based on LLVM (2018) [pdf]
This is a valid concern, for sure. In fact, these are called Equivalent Mutants. We observed it several times, here are some examples. You flip the if/then branches and the code essentially does the same, switching from a fast to slow implementation of the same algorithm. Another example is mutating the code in a C++ destructor, which is not easy to test.

With that being said, even despite the equivalent mutants, you can get a pretty good insight. Here is an example of finding from a proprietory real-time OS used in the space industry: https://gist.github.com/AlexDenisov/b5d2e23457b88813b5ab9d5d... (this is a part of an email which I could safely post online).

AlexDenisov··on Ask HN: Who is hiring? (August 2018)
PTScientists GmbH | Software Developers and Engineers for Space Industry | Berlin, Germany | ONSITE | Full-time | https://ptscientists.com

PTScientists is a private space company based in the vibrant city of Berlin. We are currently growing our team of engineers to support Mission to the Moon – which we hope will be the first privately funded mission to land on the lunar surface. We are working with key technology partners Audi and Vodafone Germany to enable a range of scientific, technological and cultural firsts with Mission to the Moon. Our team is made up of smart, passionate and ambitious people and we are proud to be contributing to the next chapter of space exploration.

Current openings:

Associate/Senior Software Developer: https://ptscientists.com/careers/associate-senior-software-d...

Embedded Software Engineer C/C++: https://ptscientists.com/careers/embedded-software-engineer-...

FPGA/Embedded Developer: https://ptscientists.com/careers/fpga-embedded-developer/

AlexDenisov··on Ask HN: Who is hiring? (May 2018)
PTScientists (http://ptscientists.com) | FPGA/Embedded Developer, Electrical Engineer, GNC Engineer | Berlin, Germany | Full time, ONSITE

PTScientists is a private space company based in the vibrant city of Berlin.

We are currently growing our team of engineers to support Mission to the Moon - which we hope will be the first privately funded mission to land on the lunar surface.

We are developing the transport and communications infrastructure required to enable future lunar missions and possible human settlement.

Find out more about the company and current openings here:

http://ptscientists.com/careers/fpga-embedded-developer/

http://ptscientists.com/careers/electrical-engineer/

http://ptscientists.com/careers/gnc-engineer/

AlexDenisov··on Ask HN: What did you work on in 2017?
Production ready tool for Mutation Testing targeting compiled languages (C, C++, Rust, Swift):

https://github.com/mull-project/mull

AlexDenisov··on Uncle Bob and Silver Bullets
I think this is a fallacy. I believe another pipeline does not necessarily produce better doctors. They also make mistakes; sometimes those mistakes cost people lives.
AlexDenisov··on Uncle Bob and Silver Bullets
Exactly, this is what I mean by "do not scale." It takes many years, if not decades for one to become a decent developer. We simply cannot afford this.
AlexDenisov··on Uncle Bob and Silver Bullets
Discipline is a good thing, but it does not scale.

I work on a tool for mutation testing for C/C++[1] for a few years now. During this time I was thinking about tests, tools, people, etc. a lot. Here is the summary of my musings:

Quality of software depends on several factors such as hardware, operating system, programming language and tooling used to build the software in the first place, etc. For decades we try to improve each of those aspects. But, the most significant and most harmful factor is the human. Naturally, we cannot improve developers, but we can decrease the destructive influence of a human being by using better tooling.

[1] https://github.com/mull-project/mull

AlexDenisov··on Collection of Papers on Database Management Systems
Awesome, thanks for the link.
AlexDenisov··on Snowman: native code to C/C++ decompiler
Yes, we are going to record it. But the publishing is up to the speaker. I will post the link here if it happens.
AlexDenisov··on Snowman: native code to C/C++ decompiler
For those who curious and who is in Berlin:

There is going to be an event on this Thursday (July 27, 2017) where the author of this tool will be talking about decompilation.

https://www.meetup.com/LLVM-Social-Berlin/events/241197713/

AlexDenisov··on Resources about programming practices for writing safety-critical software
I have seen so many comments and references like this one, so I went and read the whole investigation report.

1. There was a spacecraft (MCO) and a module that was sending some data from the Earth.

2. The module was delivered late when MCO was on its way for 4 (!) months already before that staff manually calculated the needed data.

3. Some teams switched into "defensive mode" not willing to communicate and fixing the problem when it was clear.

AlexDenisov··on List of scientific papers found in OpenJDK source code
You can just grep by PDF name/url and find the code.
AlexDenisov··on List of scientific papers found in OpenJDK source code
TIL about DOI :)
AlexDenisov··on List of scientific papers found in OpenJDK source code
That's a lot :) Some of your findings are actually listed in the original article, but not all of them obviously.
AlexDenisov··on Ask HN: Who is hiring? (July 2016)
Uberchord (https://www.uberchord.com) | Full-time, onsite in Berlin, Germany, offers Visa Support | Backend Web Engineer | join@uberchord.com

Uberchord is a new guitar learning platform for iOS with patent-pending realtime audio recognition. Featured as one of the best apps 2016, our users write us love letters – seriously. As part of our team you will make a difference in music learning.

HELP US TO CHANGE MUSIC EDUCATION

We are a small team of top engineers, musicians and experienced entrepreneurs who set out to change the way we learn musical instruments. We developed a unique audio recognition technology that allows us to understand the player in real-time to give constant feedback on an unprecedented level. Our goal is nothing short of audacity – make musicians, not just players.

Our users give us glowing reviews, Apple seems to like us too, and with a top-tier investor we are ready for the next level.

WANT TO BE PART OF IT?

We are currently looking for a senior full-stack web engineer (ideally with good knowledge of Parse and Google Cloud) to work on our upcoming music platform. You consider yourself a top software engineer. You have a degree in computer science and have a few years of serious coding in large and complex projects under your belt. Most of all, however, you love to create beautiful apps, care about music and code alike and want to be part of a small, hard working team. We offer you plenty of room to apply your creativity, learn new stuff and grow. And yes, we pay well and offer shares.

We are located at the heart of Europe’s music tech scene, at Factory Berlin, Soundcloud’s headquarter.

These are full-time positions in Berlin. We don’t care where you come from, we’ll help you to relocate.

Reach out to us: join@uberchord.com

https://www.uberchord.com/jobs/

AlexDenisov··on How GNU Make is tested
That was a typo :)
AlexDenisov··on Ask HN: Who is hiring? (May 2015)
Blacklane - Berlin, Germany

- Software Engineers: iOS, Android, Web (polyglots are welcome)

- UI/UX Expert, mostly for mobile

Company helps with relocation and Blue Card (working visa) for non-eu citizens.

If you want to talk to engineers (preferable): timo.roessner (at) blacklane.com or alexey.denysov (at) blacklane.com

If you still want to talk to HRs: career@blacklane.com

AlexDenisov··on Sleipnir: BDD-style framework for Swift
Thank you, guys. Our designer did it (https://dribbble.com/shagov)
AlexDenisov··on Sleipnir: BDD-style framework for Swift
Thank you! Fixed.