What it feels like when Rust saves your bacon • Hacker News Board

Re: What it feels like when Rust saves your bacon

#101

Post by [deleted] » Fri, Jun 24, 2022, 2:34 PM UTC

nemothekid wrote: post #94

shuger wrote: post #31

Earlier quoted context omitted.

I work in probably what is considered one of the least "safe" languages: C++ The issues that Rust is supposed to help with are simply not what we spent time on. All the bugs reported are pretty much exclusively root caused to "business logic". From recent time I can recall only one that was a programming mistake and not architecture/business logic related. It was a missing break in a switch that already had some fall…

> The issues that Rust is supposed to help with are simply not what we spent time on. There could be plenty of bugs in your codebase but just because you don't spend time on them doesn't mean they don't exist. Hundreds of millions of people used OpenSSL everyday for 2 years after the Heartbleed bug was introduced. It didn't cause any obviously broken code until someone exploited it to read credit card numbers off of…

[deleted]

Re: What it feels like when Rust saves your bacon

#102

Post by jhgb » Fri, Jun 24, 2022, 2:35 PM UTC

Macha wrote: post #79

lmm wrote: post #70

Earlier quoted context omitted.

> The issues that Rust is supposed to help with are simply not what we spent time on. All the bugs reported are pretty much exclusively root caused to "business logic". Everyone claims this, probably because business logic bugs are more memorable. But I've never seen it match the real statistics. According to the best published data, null alone is something like 30-70% of bugs, you just don't remember them because th…

It depends on the person's mental categorisation of bugs too. For example I could see someone classifying null bugs as business logic bugs because "the business logic didn't account for that information not always being there"

It's a language bug, really. If you're expected to say what the individual things in your program are allowed to be (like you have to in C++, Java, C# etc.), and you say "foo is a BarBaz object", and the language and compiler allow you to set foo to something that isn't actually a BarBaz object and this is considered OK, then the language is botched.

Re: What it feels like when Rust saves your bacon

#103

Post by Agingcoder » Fri, Jun 24, 2022, 2:49 PM UTC

shuger wrote: post #31

bestouff wrote: post #22

Earlier quoted context omitted.

Yeah no. In my experience, when several people commit to a common C/C++ codebase this kind of issue become really exhausting when it happens more than once, and the symptoms may be so subtle it's a bitch to debug. Rust lowers your mental load. You spend more time being creative and way less time debugging "obvious" (or not) mechanical problems (reference not-on-stack-anymore variables, use-after-free, concurrent writ…

I work in probably what is considered one of the least "safe" languages: C++ The issues that Rust is supposed to help with are simply not what we spent time on. All the bugs reported are pretty much exclusively root caused to "business logic". From recent time I can recall only one that was a programming mistake and not architecture/business logic related. It was a missing break in a switch that already had some fall…

In practice for you. Where I am, things are very different! Buffer overflows and memory corruptions, threading issues, uninitialized variables, etc appear on a very regular basis, and end up being very difficult to debug, mostly because the moment where you corrupt memory and the moment it triggers a bug can be very far apart.

Re: What it feels like when Rust saves your bacon

#104

Post by kajaktum » Fri, Jun 24, 2022, 2:51 PM UTC

jesse__ wrote: post #95

jackmott42 wrote: post #91

Earlier quoted context omitted.

I see many C++ programmers say stuff like this, and maybe it is the case that studios exist which can do C++ without mistakes related to memory management or sigils and so on, but I also observe that: 1. High quality teams like the Linux kernel team and PostgreSQL, do periodically have serious security bugs that are things Rust would have caught. 2. I see sometimes C++ instructors making the same claims you do and th…

I'd venture that the development slowdown from using rust is closer to 50% than 5%. Even just compile times probably slow down that much, not to mention you have to write (sometimes) as much as 10x code to express yourself. The specific exercise I have in mind is a lockless thread queue. < 20 lines in C .. ~200 lines in Rust.

>The specific exercise I have in mind is a lockless thread queue. Do they have an equivalent API? Rust does have a hard time explaining very, very low level stuff that you'd have to do unsafe and various magicks. But once you get the unsafe details right, the consumer API for them tends to be extremely rigid and fool proof.

Re: What it feels like when Rust saves your bacon

#105

Post by lelanthran » Fri, Jun 24, 2022, 2:55 PM UTC

bschwindHN wrote: post #46

lelanthran wrote: post #43

Earlier quoted context omitted.

I'm not saying that a large number of CVEs won't be prevented in Rust, I'm saying that so few bugs are CVEs that the trade-off is not always worth it. If you have 1000s of bug reports, of which 5 are CVEs, and then have 3 of those 5 be preventable, most dev teams are still going to consider the cost/benefit of going through the pain of developing a long-term product in Rust, or of switching to Rust altogether.

> of which 5 are CVEs Those 5 are just the ones you know about...

> Those 5 are just the ones you know about...

It's pointless making a cost/benefit analysis on things that probably don't exist.

Re: What it feels like when Rust saves your bacon

#106

Post by lelanthran » Fri, Jun 24, 2022, 2:56 PM UTC

girvo wrote: post #69

lelanthran wrote: post #43

Earlier quoted context omitted.

I'm not saying that a large number of CVEs won't be prevented in Rust, I'm saying that so few bugs are CVEs that the trade-off is not always worth it. If you have 1000s of bug reports, of which 5 are CVEs, and then have 3 of those 5 be preventable, most dev teams are still going to consider the cost/benefit of going through the pain of developing a long-term product in Rust, or of switching to Rust altogether.

I suppose it comes down to risk assessment; if those CVEs are critical “fix this now or the world catches fire”, then their relative infrequency seems to be outweighed by their impact, no?

> I suppose it comes down to risk assessment; if those CVEs are critical “fix this now or the world catches fire”, then their relative infrequency seems to be outweighed by their impact, no?

No.

Re: What it feels like when Rust saves your bacon

#107

Post by scoutt » Fri, Jun 24, 2022, 3:00 PM UTC

proto_lambda wrote: post #62

dijit wrote: post #58

Earlier quoted context omitted.

For whatever it’s worth: I think it’s harder to learn rust as a C++ programmer than it is for a new programmer. Reason being that you have to unlearn your paradigm before you’re able to learn the new paradigm; and it’s made slightly worse by giving the appearance of similarity (since certain concepts map directly, like flow control and loops).

One big hurdle for C++ programmers learning Rust that I've seen time and time again in various community support channels is fixing their trust issues with the compiler. They are so used to compiler output being useless or worse than useless, they are unable to take advantage of rustc's stellar diagnostics (which frequently tell you exactly what you need to change to make things work) until they force themselves to a…

> big hurdle

Without going much further, to me it's the syntax. I can write some Rust lines of code, and I appreciate the compiler output to correct my syntax. But it's really difficult to me to read code written by others. I can't open a random file of a Rust project and have a minimal clue of what's going on

After years of C and some C++, I have a parser implanted in my cerebellum, and it's hard to adapt it to Rust. To me, reading Rust feels like forcing an optical nerve to see something very small.

Case in point, the code in this article.

Re: What it feels like when Rust saves your bacon

#108

Post by pkulak » Fri, Jun 24, 2022, 3:09 PM UTC

jesse__ wrote: post #95

jackmott42 wrote: post #91

Earlier quoted context omitted.

I see many C++ programmers say stuff like this, and maybe it is the case that studios exist which can do C++ without mistakes related to memory management or sigils and so on, but I also observe that: 1. High quality teams like the Linux kernel team and PostgreSQL, do periodically have serious security bugs that are things Rust would have caught. 2. I see sometimes C++ instructors making the same claims you do and th…

I'd venture that the development slowdown from using rust is closer to 50% than 5%. Even just compile times probably slow down that much, not to mention you have to write (sometimes) as much as 10x code to express yourself. The specific exercise I have in mind is a lockless thread queue. < 20 lines in C .. ~200 lines in Rust.

A lockless thread queue (not entirely sure what that would be, sorry; a queue in front of a pool?) seems like the kind of low-level library that could be written with liberal use of unsafe. No need to flagellate yourself on the altar of compile-time safety.

Re: What it feels like when Rust saves your bacon

#109

Post by cbarrick » Fri, Jun 24, 2022, 3:28 PM UTC

shuger wrote: post #8

This article is super overcomplicated. All it had to say was that rust tells you when you keep reference to on stack variable after it goes out of scope. Context provided adds nothing. I must say - as someone who doesn't use rust - I haven't had this type of issue in years, and when I did it wasn't hard to debug. You get corrupted data, set data breakpoint and in the provided example you will see it being modified by…

Earlier this month we integrated a C++ library written by my team with a server written by another team.

We saw the data corruption, and we knew it was a reference issue, but it took quite a bit of effort to track down. The cause was confusion around string_view and string&, with different behavior when you pass each to a new thread.

Rust would have caught this much earlier and saved 3 days work.

Re: What it feels like when Rust saves your bacon

#110

Post by boris » Fri, Jun 24, 2022, 3:31 PM UTC

jackmott42 wrote: post #91

shuger wrote: post #31

Earlier quoted context omitted.

I work in probably what is considered one of the least "safe" languages: C++ The issues that Rust is supposed to help with are simply not what we spent time on. All the bugs reported are pretty much exclusively root caused to "business logic". From recent time I can recall only one that was a programming mistake and not architecture/business logic related. It was a missing break in a switch that already had some fall…

I see many C++ programmers say stuff like this, and maybe it is the case that studios exist which can do C++ without mistakes related to memory management or sigils and so on, but I also observe that: 1. High quality teams like the Linux kernel team and PostgreSQL, do periodically have serious security bugs that are things Rust would have caught. 2. I see sometimes C++ instructors making the same claims you do and th…

> There are however valid questions, like if Rust slows down your development say, 5%, would you get more net safety from spending 5% more time testing/fuzzing c++ code instead? etc.

I think a similarly valid question is how often you resorted to dynamic allocations just to get the borrow checker off your back. If your Rust version uses 5% more dynamic memory (with the corresponding performance and memory footprint penalty), is it perhaps worth staying with C/C++ and spending more development time on testing/fuzzing?