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Fixing a bug in Google Chrome as a first-time contributor

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Re: Fixing a bug in Google Chrome as a first-time contributor

#111

Post by doublepg23 »

kllrnohj wrote: post #105
mrweasel wrote: post #15

Not that I really see away around it, given the size and feature set of Chrome, but those build requirements are just crazy. It kinda throws the open source and "everyone can contribute" model out the window, if you can't afford a pretty insane workstation then you're going to have a bad time. I doubt that Firefox is better, I seem to remember that building Firefox and the VIA C3 processor years back as around half a…

16 core CPU, 64GB RAM, and 100GB of storage is definitely not a budget build, but I don't really see how that would be a "pretty insane workstation", either. That's firmly in consumer space these days and has been for a few years. But that's also not a requirement , either, that's just what it took for a 40 minute clean build time.

Yeah that's a very doable build on AM4 Ryzen. I'd hope someone with C++ chops to hack on Chrome would be able to afford that.

Re: Fixing a bug in Google Chrome as a first-time contributor

#112

Post by bgirard »

kccqzy wrote: post #71
bgirard wrote: post #44

Earlier quoted context omitted.

> Chromium's codebase isn't so bad for a first timer. Agreed > It took me like 30 minutes I can tell you didn't need to build it ;)

Why build it if you are just reading? I find https://source.chromium.org/chromium wonderful. With things like go-to-definition and find-all-overridden-functions working wonderfully well. I find this to be ideal when working with a large codebase. I don't even need an editor with fancy intelligence features and LSP integration; a bare bones vim or emacs paired with a website with all the intelligence already there.

> Why build it if you are just reading?

Is this a serious question? Assuming it is, to insert printf statement, or attach a debugger and step through the program and take backtraces to supplement or confirm the information you gather from reading the code.

Re: Fixing a bug in Google Chrome as a first-time contributor

#113

Post by oops »

quirino wrote: post #58

There's this one Chrome (?) bug I've been experiencing for a long time on Linux. Every once in a while, the browser detects I'm typing "±±±±±±+..." and writes that to any selected text input. It stops when I type anything, but sometimes comes back rather quickly. I thought it was a keyboard issue, but it doesn't affect Firefox or other applications, only Chrome based ones like Spotify and VSCode. I've found no other…

> I've found no other mention of this on the internet

Here's one! (different character, but same issue it seems?)

https://www.reddit.com/r/linuxquestions/comments/1cbarz5/ele...

> and I'd love to to hunt this down and fix it but have no clue where to start. I guess the first step would be to consistently reproduce the bug...

I am not familiar with Chromium at all, and I also don't run Linux on the desktop as I'm guessing from your video you do (?) so take this with a grain of salt...

I would start looking at the focus and key event handlers. e.g. maybe log the contents of pressed_keys and/or step thru the code from the beginning of the focus handler. It looks like this might be the place:

https://github.com/chromium/chromium/blob/01ab59ae08a38a361d...

https://github.com/chromium/chromium/blob/de351fd416ec36beeb...

Even if you can't repro it, you may be able to figure out the issue by just reading thru that code with some theories in mind. e.g. Since pressing another key seems to fix it, maybe look at what the code is doing there... my guess is the release event fixes whatever corrupted state it is in upon focus.

Re: Fixing a bug in Google Chrome as a first-time contributor

#114

Post by kccqzy »

bgirard wrote: post #112
kccqzy wrote: post #71

Earlier quoted context omitted.

Why build it if you are just reading? I find https://source.chromium.org/chromium wonderful. With things like go-to-definition and find-all-overridden-functions working wonderfully well. I find this to be ideal when working with a large codebase. I don't even need an editor with fancy intelligence features and LSP integration; a bare bones vim or emacs paired with a website with all the intelligence already there.

> Why build it if you are just reading? Is this a serious question? Assuming it is, to insert printf statement, or attach a debugger and step through the program and take backtraces to supplement or confirm the information you gather from reading the code.

Yes it's a serious question. And no, "reading" doesn't involve inserting printf statements or taking backtraces. These are different activities. That's called debugging and not reading.

The OP's scenario is being curious how Chromium does something: so it suffices to find the relevant snippet and then copy it elsewhere. The Chromium code is assumed to be already working and does not need debugging.

Re: Fixing a bug in Google Chrome as a first-time contributor

#115

Post by bgirard »

kccqzy wrote: post #114
bgirard wrote: post #112

Earlier quoted context omitted.

> Why build it if you are just reading? Is this a serious question? Assuming it is, to insert printf statement, or attach a debugger and step through the program and take backtraces to supplement or confirm the information you gather from reading the code.

Yes it's a serious question. And no, "reading" doesn't involve inserting printf statements or taking backtraces. These are different activities. That's called debugging and not reading. The OP's scenario is being curious how Chromium does something: so it suffices to find the relevant snippet and then copy it elsewhere. The Chromium code is assumed to be already working and does not need debugging.

My point is that for engineers like myself, it's much easier to read code if I can also have access to debugging features.

> The Chromium code is assumed to be already working and does not need debugging.

Even if it doesn't need debugging, debugging features can help engineers understand the code better.

Re: Fixing a bug in Google Chrome as a first-time contributor

#116

Post by aftbit »

bobajeff wrote: post #38
mherrmann wrote: post #10

Congratulations! And thank you for the great write-up. I work with the Chromium code base a lot, and it can indeed be daunting. I use Sublime Text, which treats the code as plain text, apart from syntax highlighting. But it's also possible with at least VS Code to get some more intelligence, such as going to the definition or declaration of a function, etc. People who have now become interested in creating their own…

>So how much does it cost to maintain a Chromium fork? >It obviously depends on the number of customizations your browser has, and on how quickly you want to incorporate security fixes from upstream. Chromium is one of the world's most complex pieces of software, and you need very capable engineers and powerful hardware to match this. It is going to be expensive. And not just once, but also on an ongoing basis. This…

I dunno, I've maintained a personal fork since around Chrome 100 or so. I am only targeting builds on Linux, I don't care about branding, and my patches are limited to about 300 lines total. The initial fork and figuring out the build process took probably 20 hours. After that, I've only had to spend on average around one hour per release of "engineering time" to keep my patches current. The build takes about an hour of machine time on my 5950x.

I'm not saying it's trivial by any means, but I don't think it's outside the range of a motivated hobbyist or a small startup. I don't think you really need "very capable engineers" personally. I barely know C or C++ and I haven't had too much trouble working with the codebase.

Re: Fixing a bug in Google Chrome as a first-time contributor

#117

Post by indrora »

macqm wrote: post #79

>Because of this huge codebase size, I wasn't able to get VS Code's C++ extension to work very well with the project. Features like go-to definition (which I usually rely on heavily when navigating codebases) and find references didn't work well or at all, and one of my CPU cores would stay stuck at 100% permanently while the project was open. Chromium Code Search [1] tool is very helpful with that and I believe ther…

Oh yeah, Code Search is good.

it is not as good as the search built into Azure Devops [1] however. You don't know power search until you've used a search tool built on the backs of the devs of Windows. Being able to say "Uhhhh I know it was a macro called DeBeanIt2k near a comment with "HACK" in it" gets turned into "comment:HACK macro:DeBeanIt2k" and you get answers back is super nice. There's also an API for it.

1: https://learn.microsoft.com/en-us/azure/devops/project/searc...

Re: Fixing a bug in Google Chrome as a first-time contributor

#118

Post by kgeist »

kccqzy wrote: post #114
bgirard wrote: post #112

Earlier quoted context omitted.

> Why build it if you are just reading? Is this a serious question? Assuming it is, to insert printf statement, or attach a debugger and step through the program and take backtraces to supplement or confirm the information you gather from reading the code.

Yes it's a serious question. And no, "reading" doesn't involve inserting printf statements or taking backtraces. These are different activities. That's called debugging and not reading. The OP's scenario is being curious how Chromium does something: so it suffices to find the relevant snippet and then copy it elsewhere. The Chromium code is assumed to be already working and does not need debugging.

>The OP's scenario is being curious how Chromium does something: so it suffices to find the relevant snippet and then copy it elsewhere. The Chromium code is assumed to be already working and does not need debugging.

To clear myself of any wrongdoing in regards to copyright :) They had a very nice comment explaining how the workaround works, and we used a different image manipulation library, so I couldn't, and didn't, copy it as is.

So not only it was easy to find the workaround in their huge codebase, they also explained it well so I could replicate it in our codebase from scratch.

Re: Fixing a bug in Google Chrome as a first-time contributor

#119

Post by xboxnolifes »

Quothling wrote: post #11
sd9 wrote: post #4

Earlier quoted context omitted.

The changing bit is at the beginning, unless I misunderstand you. Worker and Worklet are primitives, you can't really split them up. You can't have a LetWorkGlobalScope and an ErWorkGlobalScope, so WorkerGlobalScope and WorkletGlobalScope is the best you can do. That said, I usually prefer the changing bit at the end. So something like GlobalScopeForWorker, GlobalScopeForWorklet. But then that's clunky, so we're back…

> That said, I usually prefer the changing bit at the end. So something like GlobalScopeForWorker, GlobalScopeForWorklet. But then that's clunky, so we're back at WorkerGlobalScope and WorkletGlobalScope again. I've done this and it's always ended up biting me in the ass when I want to auto-complete and have 9 million "GlobalScope..." to chose from. Which is where "Work..." becomes handy.

On the other hand, it can be nice for other types of autocomplete usage. Say I know I'm looking for a GlobalScope, but I just don't know which one. Type "GlobalScope" and you get a nice list of everything prefixed with it. It's nice for things like Error enums, or similar usages. I know I'm looking for an Error, but I'm not sure of all the ones available to me.
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