Make codegen_call_inner a bit more readable

[rust.git] / Readme.md

diff --git a/Readme.md b/Readme.md
index 3c07f08f95159340f422e69e2cc6bf059d6342d9..230a08191ff5bfdf032f14f6a021adb569d1a233 100644 (file)
--- a/Readme.md
+++ b/Readme.md
@@ -1,50 +1,48 @@
 # Work in progress cranelift codegen backend for rust
 
-> ⚠⚠⚠ This doesn't do anything useful yet ⚠⚠⚠
+> ⚠⚠⚠ This doesn't do much useful yet ⚠⚠⚠
 
 ## Building
 
 ```bash
 $ git clone https://github.com/bjorn3/rustc_codegen_cranelift.git
 $ cd rustc_codegen_cranelift
-$ rustup override set nightly
-$ git submodule update --init
-$ cargo build
+$ ./prepare.sh # downloads and patches sysroot src and installs hyperfine for benchmarking
+$ ./test.sh
 ```
 
 ## Usage
 
+`$cg_clif_dir` is the directory you cloned this repo into in the following instruction.
+
+### Rustc
+
 ```bash
-$ rustc -Zcodegen-backend=$(pwd)/target/debug/librustc_codegen_cranelift.so my_crate.rs --crate-type lib -Og
+$ rustc -Cpanic=abort -Zcodegen-backend=$cg_clif_dir/target/debug/librustc_codegen_cranelift.so my_crate.rs
 ```
 
-## Building libcore
+### Cargo
 
 ```bash
-$ rustup component add rust-src
-$ ./prepare_libcore.sh
-$ ./build.sh
+$ RUSTFLAGS="-Cpanic=abort -Zcodegen-backend=$cg_clif_dir/target/debug/librustc_codegen_cranelift.dylib --sysroot $cg_clif_dir/build_sysroot/sysroot" cargo run
 ```
 
-> This should stop with `error: aborting due to <...> previous errors`
->
-> Please submit a bug if not
-
 ## Not yet supported
 
-* Checked binops
-* Drop glue
+* Good non-rust abi support ([scalar pair and vector are passed by-ref](https://github.com/bjorn3/rustc_codegen_cranelift/issues/10))
+* Checked binops ([some missing instructions in cranelift](https://github.com/CraneStation/cranelift/issues/460))
+* Inline assembly ([no cranelift support](https://github.com/CraneStation/cranelift/issues/444))
+* Varargs ([no cranelift support](https://github.com/CraneStation/cranelift/issues/212))
+* libstd (needs varargs and some other stuff) ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/146))
+* u128 and i128 ([no cranelift support](https://github.com/CraneStation/cranelift/issues/354))
+* SIMD ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/171))
+
+## Troubleshooting
 
-* Building libraries
-* Other call abi's
-* Unsized types
-* Slice indexing
-* Sub slice
+### Can't compile
 
-* Inline assembly
-* Custom sections
+Try updating your nightly compiler. You can try to use an nightly a day or two older if updating rustc doesn't fix it. If you still can't compile it, please fill an issue.
 
-## Known errors
+### error[E0463]: can't find crate for `std` while compiling a no_std crate
 
-* cranelift-module api seems to be used wrong, thus causing panic for some consts
-* cranelift-codegen doesn't have encodings for some instructions for types smaller than I32
+If you use `RUSTFLAGS` to pass `-Zcodegen-backend` to rustc, cargo will compile `build-dependencies` with those flags too. Because this project doesn't support libstd yet, that will result in an error. I don't know of any way to fix this. :(