> Google has probably the largest C++ codebase in the world. Migrating to Rust would be so expensive that the board would squash it.

Google is transitioning large parts of Android to Rust and there is now first-party code in Chromium and V8 in Rust. I’m sure they’ll continue to write new C++ code for a good while, but they’ve made substantial investments to enable using Rust in these projects going forward.

Also, if you’re imagining the board of a multi-trillion dollar market cap company is making direct decisions about what languages get used, you may want to check what else in this list you are imagining.

▲

pjmlp 2 hours ago | parent [-]

Unless rules have changed Rust is only allowed a minor role in Chrome.

> Based on our research, we landed on two outcomes for Chromium.

> We will support interop in only a single direction, from C++ to Rust, for now. Chromium is written in C++, and the majority of stack frames are in C++ code, right from main() until exit(), which is why we chose this direction. By limiting interop to a single direction, we control the shape of the dependency tree. Rust can not depend on C++ so it cannot know about C++ types and functions, except through dependency injection. In this way, Rust can not land in arbitrary C++ code, only in functions passed through the API from C++.

> We will only support third-party libraries for now. Third-party libraries are written as standalone components, they don’t hold implicit knowledge about the implementation of Chromium. This means they have APIs that are simpler and focused on their single task. Or, put another way, they typically have a narrow interface, without complex pointer graphs and shared ownership. We will be reviewing libraries that we bring in for C++ use to ensure they fit this expectation.

-- https://security.googleblog.com/2023/01/supporting-use-of-ru...

Also even though Rust would be a safer alternative to using C and C++ on the Android NDK, that isn't part of the roadmap, nor the Android team provides any support to those that go down that route. They only see Rust for Android internals, not app developers

If anything, they seem more likely to eventually support Kotlin Native for such cases than Rust.

▲

johncolanduoni an hour ago | parent [-]

> Unless rules have changed Rust is only allowed a minor role in Chrome.

I believe the Chromium policy has changed, though I may be misinterpreting: https://chromium.googlesource.com/chromium/src/+/refs/heads/...

The V8 developers seem more excited to use it going forward, and I’m interested to see how it turns out. A big open question about the Rust safety model for me is how useful it is for reducing the kind of bugs you see in a SOTA JIT runtime.

> They only see Rust for Android internals, not app developers

I’m sure, if only because ~nobody actually wants to write Android apps in Rust. Which I think is a rational choice for the vast majority of apps - Android NDK was already an ugly duckling, and a Rust version would be taken even less seriously by the platform.

	▲	pjmlp an hour ago \| parent [-]
		That looks only to be the guidelines on how to integrate Rust projects, not that the policy has changed. The NDK officially it isn't to write apps anyway, people try to do that due to some not wanting to touch Java or Kotlin, but that has never been the official point of view from Android team since it was introduced in version 2, rather: > The Native Development Kit (NDK) is a set of tools that allows you to use C and C++ code with Android, and provides platform libraries you can use to manage native activities and access physical device components, such as sensors and touch input. The NDK may not be appropriate for most novice Android programmers who need to use only Java code and framework APIs to develop their apps. However, the NDK can be useful for cases in which you need to do one or more of the following: > Squeeze extra performance out of a device to achieve low latency or run computationally intensive applications, such as games or physics simulations. > Reuse your own or other developers' C or C++ libraries. So it would be expected that at least for the first scenario, Rust would be a welcomed addition, however as mentioned they seem to be more keen into supporting Kotlin Native for it.