Make codegen_call_inner a bit more readable

[rust.git] / Readme.md

diff --git a/Readme.md b/Readme.md
index f43f909e9c7a9026c928f4a876d2c45ec84ce1c7..230a08191ff5bfdf032f14f6a021adb569d1a233 100644 (file)
--- a/Readme.md
+++ b/Readme.md
@@ -7,32 +7,42 @@
 ```bash
 $ git clone https://github.com/bjorn3/rustc_codegen_cranelift.git
 $ cd rustc_codegen_cranelift
-$ rustup override set nightly # This uses unstable api's which will never be stabilized
-$ cargo install xargo         # Used for building the sysroot
-$ cargo install hyperfine     # Used for benchmarking in build.sh
-$ 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=$(pwd)/target/debug/librustc_codegen_cranelift.so my_crate.rs
+$ rustc -Cpanic=abort -Zcodegen-backend=$cg_clif_dir/target/debug/librustc_codegen_cranelift.so my_crate.rs
 ```
 
-## Build sysroot and test
+### Cargo
 
 ```bash
-$ rustup component add rust-src # Make sure the sysroot source is availablr
-$ ./prepare_libcore.sh          # Patch the sysroot source for some not yet supported things
-$ ./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
 ```
 
 ## Not yet supported
 
-* Good non-rust abi support ([non scalars are not yet supported for the "C" abi](https://github.com/bjorn3/rustc_codegen_cranelift/issues/10))
+* 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 (huge amount of work to get all intrinsics implemented, so may never be supported)
+* SIMD ([tracked here](https://github.com/bjorn3/rustc_codegen_cranelift/issues/171))
+
+## Troubleshooting
+
+### Can't compile
+
+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.
+
+### error[E0463]: can't find crate for `std` while compiling a no_std crate
+
+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. :(