Comment by tptacek
4 years ago
Nobody seriously thinks it's "Rust" that's the silver bullet either; they just believe memory-safe languages are. There are a bunch of them to choose from. We hear about Rust because it works in a bunch of high-profile cases that other languages have problems with, but there's no reason the entire iMessage stack couldn't have been written in Swift.
Fair. Two further thoughts:
1. Rust also has other safety features that may be relevant to your interests. It is Data Race Free. If your existing safe-but-slow language offers concurrency (and it might not) it almost certainly just tells you that all bets are off if you have a Data Race, which means complicated concurrent programs exhibit mysterious hard-to-debug issues -- and that puts you off choosing concurrency unless it's a need-to-have for a project. But with Data Race Freedom this doesn't happen. Your concurrent Rust programs just have normal bugs that don't hurt your brain when you think about them, so you feel free to pick "concurrency" as a feature any time it helps.
2. The big surface area of iMessage is partly driven by Parsing Untrusted File Formats. You could decide to rewrite everything in Rust, or, more plausibly, Swift. But this is the exact problem WUFFS is intended to solve.
WUFFS is narrowly targeted at explaining safely how to parse Untrusted File Formats. It makes Rust look positively care free. You say this byte from the format is an 8-bit unsigned integer? OK. And you want to add it to this other byte that's an 8-bit unsigned integer? You need to sit down and patiently explain to WUFFS whether you understand the result should be a 16-bit unsigned integer, or whether you mean for this to wrap around modulo 256, or if you actually are promising that the sum is never greater than 255.
WUFFS isn't in the same "market" as Rust, its "Hello, world." program doesn't even print Hello, World. Because it can't. Why would parsing an Untrusted File Format ever do that? It shouldn't, so WUFFS can't. That's the philosophy iMessage or similar apps need for this problem. NSO up against WUFFS instead of whatever an intern cooked up in C last week to parse the latest "must have" format would be a very different story.
Totally. I said Rust because I write Rust. Like, that's (part of) my job. Rust is no more memory safe (to my knowledge) than Swift, Java, C#, etc.
I also said "way, way less" not "not at all". I still think about memory safety in our Rust programs, I just don't allocate time to address it (today) specifically.
If we include data race safety in the definition of memory safety (which it ultimately is), then Rust is safer than any commonly used garbage collected language with access to multithreading, including Swift, Java and C#.
This is a RESF trope. We do not include Rust's notion of data race safety in the definition of memory safety as it is used in security. Not all bugs are created equal.
If you would have mentioned those other languages in your original post, it might have amplified your valuable and important point even better, rather than triggering some readers effectively accusing you of shilling.
I don’t mean this in a very critical spirit, though.
Communication is really hard - especially in a large setting where not everyone reads you in the same context, and not everyone means well.
On balance, you post was valuable to me!
I mentioned Rust because I write Rust professionally. If I wrote Java professionally, as I used to, I would have said "java". So you're probably correct that I could preempt stupid people's posts, but I don't care about the dregs of HN reading into my very clear, simple statement, just because they're upset about rust or whatever. It's just not worth it to me.
I'm glad the post was of value to you. The talk is really good and I think more people should read it.
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Agreed. I was simply mostly addressing this person's obvious beef with Rust.
It also doesn't help that Rust has this addictive nature and once you tasted your first major Rust program and tamed the borrow checker, you will want to keep using it everywhere. And that's the reason why people keep looking around to rewrite something in Rust. It's in the same category as any other banned drug :)
That has not been my experience.