Rust Platform Support

The Rust compiler runs on, and compiles to, a great number of platforms, though not all platforms are equally supported. Rust's support levels are organized into three tiers, each with a different set of guarantees.

Platforms are identified by their "target triple" which is the string to inform the compiler what kind of output should be produced. The columns below indicate whether the corresponding component works on the specified platform.

Tier 1

Tier 1 platforms can be thought of as "guaranteed to work". Specifically they will each satisfy the following requirements:

• Official binary releases are provided for the platform.
• Automated testing is set up to run tests for the platform.
• Landing changes to the rust-lang/rust repository's master branch is gated on tests passing.
• Documentation for how to use and how to build the platform is available.

Tier 2

Tier 2 platforms can be thought of as "guaranteed to build". Automated tests are not run so it's not guaranteed to produce a working build, but platforms often work to quite a good degree and patches are always welcome! Specifically, these platforms are required to have each of the following:

• Official binary releases are provided for the platform.
• Automated building is set up, but may not be running tests.
• Landing changes to the rust-lang/rust repository's master branch is gated on platforms building. For some platforms only the standard library is compiled, but for others rustc and cargo are too.

Tier 2.5

Tier 2.5 platforms can be thought of as "guaranteed to build", but without builds available through rustup. Automated tests are not run so it's not guaranteed to produce a working build, but platforms often work to quite a good degree and patches are always welcome! Specifically, these platforms are required to have each of the following:

• Automated building is set up, but may not be running tests.
• Landing changes to the rust-lang/rust repository's master branch is gated on platforms building. For some platforms only the standard library is compiled, but for others rustc and cargo are too.

This status is accidental: no new platforms should reach this state

Tier 3

Tier 3 platforms are those which the Rust codebase has support for, but which are not built or tested automatically, and may not work. Official builds are not available.

* These are bare-metal microcontroller targets that only have access to the core library, not std.

** There’s backend support for these targets but no target built into rustc (yet). You’ll have to write your own target specification file (see the links in the table). These targets only support the core library.

? These are targets that haven't yet been documented here. If you can shed some light on these platforms support, please create an issue or PR on the Rust Forge repo.

But those aren't the only platforms Rust can compile to! Those are the ones with built-in target definitions and/or standard library support. When linking only to the core library, Rust can also target "bare metal" in the x86, ARM, MIPS, and PowerPC families, though it may require defining custom target specifications to do so. All such scenarios are tier 3.