e6d1a0ed95
Support #[global_allocator] without the allocator shim This makes it possible to use liballoc/libstd in combination with `--emit obj` if you use `#[global_allocator]`. This is what rust-for-linux uses right now and systemd may use in the future. Currently they have to depend on the exact implementation of the allocator shim to create one themself as `--emit obj` doesn't create an allocator shim. Note that currently the allocator shim also defines the oom error handler, which is normally required too. Once `#![feature(default_alloc_error_handler)]` becomes the only option, this can be avoided. In addition when using only fallible allocator methods and either `--cfg no_global_oom_handling` for liballoc (like rust-for-linux) or `--gc-sections` no references to the oom error handler will exist. To avoid this feature being insta-stable, you will have to define `__rust_no_alloc_shim_is_unstable` to avoid linker errors. (Labeling this with both T-compiler and T-lang as it originally involved both an implementation detail and had an insta-stable user facing change. As noted above, the `__rust_no_alloc_shim_is_unstable` symbol requirement should prevent unintended dependence on this unstable feature.) |
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| .github | ||
| .vscode | ||
| build_sysroot | ||
| build_system | ||
| docs | ||
| example | ||
| patches | ||
| scripts | ||
| src | ||
| .cirrus.yml | ||
| .gitattributes | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.toml | ||
| clean_all.sh | ||
| config.txt | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| Readme.md | ||
| rust-toolchain | ||
| rustfmt.toml | ||
| test.sh | ||
| y.rs | ||
Cranelift codegen backend for rust
The goal of this project is to create an alternative codegen backend for the rust compiler based on Cranelift. This has the potential to improve compilation times in debug mode. If your project doesn't use any of the things listed under "Not yet supported", it should work fine. If not please open an issue.
Building and testing
$ git clone https://github.com/bjorn3/rustc_codegen_cranelift
$ cd rustc_codegen_cranelift
$ ./y.rs prepare
$ ./y.rs build
To run the test suite replace the last command with:
$ ./test.sh
For more docs on how to build and test see build_system/usage.txt or the help message of ./y.rs.
Alternatively you can download a pre built version from the releases page.
Usage
rustc_codegen_cranelift can be used as a near-drop-in replacement for cargo build or cargo run for existing projects.
Assuming $cg_clif_dir is the directory you cloned this repo into and you followed the instructions (y.rs prepare and y.rs build or test.sh).
In the directory with your project (where you can do the usual cargo build), run:
$ $cg_clif_dir/dist/cargo-clif build
This will build your project with rustc_codegen_cranelift instead of the usual LLVM backend.
For additional ways to use rustc_codegen_cranelift like the JIT mode see usage.md.
Configuration
See the documentation on the BackendConfig struct in config.rs for all
configuration options.
Not yet supported
- Inline assembly (no cranelift support)
- On UNIX there is support for invoking an external assembler for
global_asm!andasm!.
- On UNIX there is support for invoking an external assembler for
- SIMD (tracked here,
std::simdfully works,std::archis partially supported) - Unwinding on panics (no cranelift support,
-Cpanic=abortis enabled by default)
License
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.