rust/compiler/rustc_codegen_cranelift
Dylan DPC b4589a86cc
Rollup merge of #78674 - tmiasko:inline-substs-for-mir-body, r=oli-obk
inliner: Use substs_for_mir_body

Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.

Use `substs_for_mir_body` to take that into account.

Resolves #78529.
Resolves #78560.
2020-11-09 01:13:42 +01:00
..
.github/workflows
.vscode
build_sysroot
crate_patches
docs
example
patches
scripts fix shellcheck error of SC2068 2020-11-06 20:33:12 +09:00
src Rollup merge of #78674 - tmiasko:inline-substs-for-mir-body, r=oli-obk 2020-11-09 01:13:42 +01:00
.gitattributes
.gitignore
build.sh
Cargo.lock
Cargo.toml
clean_all.sh
LICENSE-APACHE
LICENSE-MIT
prepare.sh
Readme.md
rust-toolchain
test.sh fix shellcheck error of SC2068 2020-11-06 20:33:12 +09:00

WIP Cranelift codegen backend for rust

⚠⚠⚠ Certain kinds of FFI don't work yet. ⚠⚠⚠

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
$ ./prepare.sh # download and patch sysroot src and install hyperfine for benchmarking
$ ./build.sh

To run the test suite replace the last command with:

$ ./test.sh

This will implicitly build cg_clif too. Both build.sh 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 (prepare.sh and build.sh or test.sh).

Cargo

In the directory with your project (where you can do the usual cargo build), run:

$ $cg_clif_dir/build/cargo.sh run

This should build and run your project with rustc_codegen_cranelift instead of the usual LLVM backend.

Rustc

You should prefer using the Cargo method.

$ $cg_clif_dir/build/cg_clif my_crate.rs

Jit mode

In jit mode cg_clif will immediately execute your code without creating an executable file.

This requires all dependencies to be available as dynamic library. The jit mode will probably need cargo integration to make this possible.

$ $cg_clif_dir/build/cargo.sh jit

or

$ $cg_clif_dir/build/cg_clif --jit my_crate.rs

Shell

These are a few functions that allow you to easily run rust code from the shell using cg_clif as jit.

function jit_naked() {
    echo "$@" | $cg_clif_dir/build/cg_clif - --jit
}

function jit() {
    jit_naked "fn main() { $@ }"
}

function jit_calc() {
    jit 'println!("0x{:x}", ' $@ ');';
}

Env vars

see env_vars.md

Not yet supported

  • Good non-rust abi support (several problems)
  • Inline assembly (no cranelift support
    • On Linux there is support for invoking an external assembler for global_asm! and asm!. llvm_asm! will remain unimplemented forever. asm! doesn't yet support reg classes. You have to specify specific registers instead.
  • SIMD (tracked here, some basic things work)