Switching to Rust's own mangling scheme on nightly

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A new Rust blog post/announcement has been posted!

TL;DR: rustc will use its own "v0" mangling scheme by default on nightly versions instead of the previous default, which re-used C++'s mangling scheme, starting in nightly-2025-11-21

Context

When Rust is compiled into object files and binaries, each item (functions, statics, etc) must have a globally unique "symbol" identifying it.

In C, the symbol name of a function is just the name that the function was defined with, such as strcmp. This is straightforward and easy to understand, but requires that each item have a globally unique name that doesn't overlap with any symbols from libraries that it is linked against. If two items had the same symbol then when the linker tried to resolve a symbol to an address in memory (of a function, say), then it wouldn't know which symbol is the correct one.

Languages like Rust and C++ define "symbol mangling schemes", leveraging information from the type system to give each item a unique symbol name. Without this, it would be possible to produce clashing symbols in a variety of ways - for example, every instantiation of a generic or templated function (or an overload in C++), which all have the same name in the surface language would end up with clashing symbols; or the same name in different modules, such as a::foo and b::foo would have clashing symbols.

Rust originally used a symbol mangling scheme based on the Itanium ABI's name mangling scheme used by C++ (sometimes). Over the years, it was extended in an inconsistent and ad-hoc way to support Rust features that the mangling scheme wasn't originally designed for. Rust's current legacy mangling scheme has a number of drawbacks:

• Information about generic parameter instantiations is lost during mangling
• It i...

Get the full details here: Switching to Rust's own mangling scheme on nightly | Rust Blog