56074b5231
The new implementation doesn't use weak lang items and instead changes `#[alloc_error_handler]` to an attribute macro just like `#[global_allocator]`. The attribute will generate the `__rg_oom` function which is called by the compiler-generated `__rust_alloc_error_handler`. If no `__rg_oom` function is defined in any crate then the compiler shim will call `__rdl_oom` in the alloc crate which will simply panic. This also fixes link errors with `-C link-dead-code` with `default_alloc_error_handler`: `__rg_oom` was previously defined in the alloc crate and would attempt to reference the `oom` lang item, even if it didn't exist. This worked as long as `__rg_oom` was excluded from linking since it was not called. This is a prerequisite for the stabilization of `default_alloc_error_handler` (#102318). |
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| .. | ||
| .github/workflows | ||
| .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.git
$ cd rustc_codegen_cranelift
$ ./y.rs prepare # download and patch sysroot src and install hyperfine for benchmarking
$ ./y.rs build
To run the test suite replace the last command with:
$ ./test.sh
This will implicitly build cg_clif too. Both y.rs build and test.sh accept a --debug argument to
build in debug mode.
Alternatively you can download a pre built version from GHA. It is listed in the artifacts section of workflow runs. Unfortunately due to GHA restrictions you need to be logged in to access it.
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/build/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, some basic things work)
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.