864fe95722
Rust builds (custom build.rs and gcc-rs users) expect to have the compiler and the linker available to them as a single command with no white space trailing. Yocto unfortunately does not conform to that. The build compiler and linker almost always have a trailing space due to how the variables are composed and the target compiler and linker are almost always more than a single command. Then if you throw ccache into the mix you'll get another command. As a result to handle all these cases properly there need to be wrappers created. This change creates wrappers for both build and target and both the linker and compiler. This likely fixes #76.
Introduction
This OpenEmbedded layer provides the rust compiler, tools for building packages (cargo), and a few example projects.
What works:
- Building rust-native, rust-cross, rust-hello-world, cargo-native
- Building Rust based projects with Cargo for the TARGET
What doesn't:
- Using anything but x86_64 as the build environment
- Probably some of the untested things
What's untested:
- rust (built for target)
Building a rust package
When building a rust package in bitbake, it's usually easiest to build with cargo using cargo.bbclass. If the package already has a Cargo.toml file (most rust packages do), then it's especially easy. Otherwise you should probably get the code building in cargo first.
Once your package builds in cargo, you can use cargo-bitbake to generate a bitbake recipe for it. This allows bitbake to fetch all the necessary dependent crates, as well as a pegged version of the crates.io index, to ensure maximum reproducibility.
Common issues when packaging things using cargo
You may run into errors similar to:
| src/lib.rs:12:1: 12:35 error: can't find crate for `ffi`
| src/lib.rs:12 extern crate "openssl-sys" as ffi;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Where a "-sys" crate (or other crate) is not found. These are typically caused
by a crate's Cargo.toml including triplet-specific dependencies and then using
the crate based on a feature (most often, #[cfg(unix)]). Until cargo and it's
ecosystem get their act together, you'll need to supply patches to the
misbehaving packages. See recipies/cargo/cargo_*.bb for an example of how to
do this.
TODO
- -crosssdk and -buildsdk packages
- Upstream local rustc patches for libdir and bindir support
Pitfalls
- TARGET_SYS must be different from BUILD_SYS. This is due to the way configuration options are tracked for different targets.
Dependencies
On the host: unknown
On the target: unknown
Maintainer(s) & Patch policy
Open a Pull Request.
The master branch supports the latest master of poky. When poky creates releases, we will create a branch with the same name as the poky release. This release branch should always work with that poky release. Note that these release branches will typically be less tested than the master branch.
All new patches against rust, rust-llvm, and cargo must have referenced upstream issues or PRs opened or an explanation why the patch cannot be upstreamed. This cooresponds to the OpenEmbedded policy for other meta layers.
Copyright
MIT OR Apache-2.0 - Same as rust