Also emit vcode when emitting clif ir while using new style backends

[rust.git] / Readme.md

diff --git a/Readme.md b/Readme.md
index f5a38f0843bc20bdfec29a6f78764cdce41a4297..b0ea95692f3f7b793ba6c0675721adf2fe4b9d50 100644 (file)
--- a/Readme.md
+++ b/Readme.md
@@ -2,41 +2,73 @@
 
 > ⚠⚠⚠ 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](https://github.com/bytecodealliance/wasmtime/blob/master/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 probably work fine. If not please open an issue.
+The goal of this project is to create an alternative codegen backend for the rust compiler based on [Cranelift](https://github.com/bytecodealliance/wasmtime/blob/main/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
+## Building and testing
 
 ```bash
 $ 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
-$ ./test.sh --release
+$ ./build.sh
 ```
 
+To run the test suite replace the last command with:
+
+```bash
+$ ./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.
+
+[GHA]: https://github.com/bjorn3/rustc_codegen_cranelift/actions?query=branch%3Amaster+event%3Apush+is%3Asuccess
+
 ## Usage
 
 rustc_codegen_cranelift can be used as a near-drop-in replacement for `cargo build` or `cargo run` for existing projects.
 
-Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`prepare.sh` and `test.sh`).
+Assuming `$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:
 
 ```bash
-$ $cg_clif_dir/cargo.sh run
+$ $cg_clif_dir/build/cargo.sh run
 ```
 
 This should build and run your project with rustc_codegen_cranelift instead of the usual LLVM backend.
 
-If you compiled cg_clif in debug mode (aka you didn't pass `--release` to `./test.sh`) you should set `CHANNEL="debug"`.
-
 ### Rustc
 
 > You should prefer using the Cargo method.
 
 ```bash
-$ rustc +$(cat $cg_clif_dir/rust-toolchain) -Cpanic=abort -Zcodegen-backend=$cg_clif_dir/target/release/librustc_codegen_cranelift.so --sysroot $cg_clif_dir/build_sysroot/sysroot my_crate.rs
+$ $cg_clif_dir/build/bin/cg_clif my_crate.rs
+```
+
+### Jit mode
+
+In jit mode cg_clif will immediately execute your code without creating an executable file.
+
+> This requires all dependencies to be available as dynamic library.
+> The jit mode will probably need cargo integration to make this possible.
+
+```bash
+$ $cg_clif_dir/build/cargo.sh jit
+```
+
+or
+
+```bash
+$ $cg_clif_dir/build/bin/cg_clif --jit my_crate.rs
 ```
 
 ### Shell
@@ -45,7 +77,7 @@ These are a few functions that allow you to easily run rust code from the shell
 
 ```bash
 function jit_naked() {
-    echo "$@" | CG_CLIF_JIT=1 rustc -Zcodegen-backend=$cg_clif_dir/target/release/librustc_codegen_cranelift.so --sysroot $cg_clif_dir/build_sysroot/sysroot - -Cprefer-dynamic
+    echo "$@" | $cg_clif_dir/build/bin/cg_clif - --jit
 }
 
 function jit() {
@@ -59,21 +91,7 @@ function jit_calc() {
 
 ## Env vars
 
-<dl>
-    <dt>CG_CLIF_JIT</dt>
-    <dd>Enable JIT mode to immediately run a program instead of writing an executable file.</dd>
-    <dt>CG_CLIF_JIT_ARGS</dt>
-    <dd>When JIT mode is enable pass these arguments to the program.</dd>
-    <dt>CG_CLIF_INCR_CACHE_DISABLED</dt>
-    <dd>Don't cache object files in the incremental cache. Useful during development of cg_clif
-    to make it possible to use incremental mode for all analyses performed by rustc without caching
-    object files when their content should have been changed by a change to cg_clif.</dd>
-    <dt>CG_CLIF_DISPLAY_CG_TIME</dt>
-    <dd>If "1", display the time it took to perform codegen for a crate</dd>
-    <dt>CG_CLIF_FUNCTION_SECTIONS</dt>
-    <dd>Use a single section for each function. This will often reduce the executable size at the
-        cost of making linking significantly slower.</dd>
-</dl>
+[see env_vars.md](docs/env_vars.md)
 
 ## Not yet supported