From d0b8896189f5b2fb472d54ed389681dff97d907b Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Wed, 15 Feb 2023 18:23:11 +0000
Subject: [PATCH] Allow building the build system using cargo

Rust's build system only handles cargo, not rustc.
---
 .cirrus.yml                      |  4 ++--
 .github/workflows/abi-cafe.yml   |  6 +++---
 .github/workflows/main.yml       | 22 ++++++++++-----------
 .github/workflows/rustc.yml      |  4 ++--
 .gitignore                       |  1 +
 .vscode/settings.json            |  3 ++-
 Cargo.toml                       |  8 --------
 Readme.md                        |  8 ++++----
 build_system/Cargo.lock          |  7 +++++++
 build_system/Cargo.toml          | 13 +++++++++++++
 build_system/build_sysroot.rs    |  4 ++--
 build_system/{mod.rs => main.rs} | 10 +++++++---
 build_system/usage.txt           | 16 ++++++++--------
 clean_all.sh                     |  2 +-
 docs/usage.md                    |  2 +-
 scripts/rustup.sh                |  2 +-
 scripts/setup_rust_fork.sh       |  2 +-
 test.sh                          |  2 +-
 y.rs                             | 33 ++------------------------------
 y.sh                             |  6 ++++++
 20 files changed, 75 insertions(+), 80 deletions(-)
 create mode 100644 build_system/Cargo.lock
 create mode 100644 build_system/Cargo.toml
 rename build_system/{mod.rs => main.rs} (98%)
 create mode 100755 y.sh

diff --git a/.cirrus.yml b/.cirrus.yml
index 1405ea74903..8b4efd4e394 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -10,7 +10,7 @@ task:
     folder: target
   prepare_script:
     - . $HOME/.cargo/env
-    - ./y.rs prepare
+    - ./y.sh prepare
   test_script:
     - . $HOME/.cargo/env
-    - ./y.rs test
+    - ./y.sh test
diff --git a/.github/workflows/abi-cafe.yml b/.github/workflows/abi-cafe.yml
index 3c40555669c..12aa69d3c79 100644
--- a/.github/workflows/abi-cafe.yml
+++ b/.github/workflows/abi-cafe.yml
@@ -46,12 +46,12 @@ jobs:
       run: rustup set default-host x86_64-pc-windows-gnu
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Build
-      run: ./y.rs build --sysroot none
+      run: ./y.sh build --sysroot none
 
     - name: Test abi-cafe
       env:
         TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
-      run: ./y.rs abi-cafe
+      run: ./y.sh abi-cafe
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index abcd1affdee..8e6c1e8ade0 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -19,7 +19,7 @@ jobs:
     - name: Rustfmt
       run: |
         cargo fmt --check
-        rustfmt --check build_system/mod.rs
+        rustfmt --check build_system/main.rs
         rustfmt --check example/*
 
 
@@ -91,15 +91,15 @@ jobs:
         sudo apt-get install -y gcc-s390x-linux-gnu qemu-user
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Build
-      run: ./y.rs build --sysroot none
+      run: ./y.sh build --sysroot none
 
     - name: Test
       env:
         TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
-      run: ./y.rs test
+      run: ./y.sh test
 
     - name: Install LLVM standard library
       run: rustup target add ${{ matrix.env.TARGET_TRIPLE }}
@@ -111,7 +111,7 @@ jobs:
       if: matrix.os != 'windows-latest' || matrix.env.TARGET_TRIPLE != 'x86_64-pc-windows-gnu'
       env:
         TARGET_TRIPLE: ${{ matrix.env.TARGET_TRIPLE }}
-      run: ./y.rs test --sysroot llvm --no-unstable-features
+      run: ./y.sh test --sysroot llvm --no-unstable-features
 
 
   # This job doesn't use cg_clif in any way. It checks that all cg_clif tests work with cg_llvm too.
@@ -165,13 +165,13 @@ jobs:
       run: cargo install hyperfine || true
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Build
-      run: CI_OPT=1 ./y.rs build --sysroot none
+      run: CI_OPT=1 ./y.sh build --sysroot none
 
     - name: Benchmark
-      run: CI_OPT=1 ./y.rs bench
+      run: CI_OPT=1 ./y.sh bench
 
 
   dist:
@@ -224,13 +224,13 @@ jobs:
         sudo apt-get install -y gcc-mingw-w64-x86-64 wine-stable
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Build backend
-      run: CI_OPT=1 ./y.rs build --sysroot none
+      run: CI_OPT=1 ./y.sh build --sysroot none
 
     - name: Build sysroot
-      run: CI_OPT=1 ./y.rs build
+      run: CI_OPT=1 ./y.sh build
 
     - name: Package prebuilt cg_clif
       run: tar cvfJ cg_clif.tar.xz dist
diff --git a/.github/workflows/rustc.yml b/.github/workflows/rustc.yml
index b2f772c4fc4..b49dc3aff7a 100644
--- a/.github/workflows/rustc.yml
+++ b/.github/workflows/rustc.yml
@@ -18,7 +18,7 @@ jobs:
         key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Test
       run: ./scripts/test_bootstrap.sh
@@ -38,7 +38,7 @@ jobs:
         key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('rust-toolchain', '**/Cargo.lock') }}
 
     - name: Prepare dependencies
-      run: ./y.rs prepare
+      run: ./y.sh prepare
 
     - name: Test
       run: ./scripts/test_rustc_tests.sh
diff --git a/.gitignore b/.gitignore
index e5d10a937ae..e6ac8c8408d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 /target
+/build_system/target
 **/*.rs.bk
 *.rlib
 *.o
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 7c8703cba50..60cb51d5663 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -6,9 +6,10 @@
     "rust-analyzer.imports.granularity.enforce": true,
     "rust-analyzer.imports.granularity.group": "module",
     "rust-analyzer.imports.prefix": "crate",
-    "rust-analyzer.cargo.features": ["unstable-features", "__check_build_system_using_ra"],
+    "rust-analyzer.cargo.features": ["unstable-features"],
     "rust-analyzer.linkedProjects": [
         "./Cargo.toml",
+        "./build_system/Cargo.toml",
         {
             "crates": [
                 {
diff --git a/Cargo.toml b/Cargo.toml
index 145b1150423..1c1f2d8577b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,13 +3,6 @@ name = "rustc_codegen_cranelift"
 version = "0.1.0"
 edition = "2021"
 
-[[bin]]
-# This is used just to teach rust-analyzer how to check the build system. required-features is used
-# to disable it for regular builds.
-name = "y"
-path = "./y.rs"
-required-features = ["__check_build_system_using_ra"]
-
 [lib]
 crate-type = ["dylib"]
 
@@ -45,7 +38,6 @@ smallvec = "1.8.1"
 unstable-features = ["jit", "inline_asm"]
 jit = ["cranelift-jit", "libloading"]
 inline_asm = []
-__check_build_system_using_ra = []
 
 [package.metadata.rust-analyzer]
 rustc_private = true
diff --git a/Readme.md b/Readme.md
index 7e9945578a5..9469feea0cb 100644
--- a/Readme.md
+++ b/Readme.md
@@ -10,8 +10,8 @@ If not please open an issue.
 ```bash
 $ git clone https://github.com/bjorn3/rustc_codegen_cranelift
 $ cd rustc_codegen_cranelift
-$ ./y.rs prepare
-$ ./y.rs build
+$ ./y.sh prepare
+$ ./y.sh build
 ```
 
 To run the test suite replace the last command with:
@@ -20,7 +20,7 @@ To run the test suite replace the last command with:
 $ ./test.sh
 ```
 
-For more docs on how to build and test see [build_system/usage.txt](build_system/usage.txt) or the help message of `./y.rs`.
+For more docs on how to build and test see [build_system/usage.txt](build_system/usage.txt) or the help message of `./y.sh`.
 
 ## Precompiled builds
 
@@ -35,7 +35,7 @@ If you want to use `cargo clif build` instead of having to specify the full path
 
 rustc_codegen_cranelift can be used as a near-drop-in replacement for `cargo build` or `cargo run` for existing projects.
 
-Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`y.rs prepare` and `y.rs build` or `test.sh`).
+Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`y.sh prepare` and `y.sh build` or `test.sh`).
 
 In the directory with your project (where you can do the usual `cargo build`), run:
 
diff --git a/build_system/Cargo.lock b/build_system/Cargo.lock
new file mode 100644
index 00000000000..86268e19160
--- /dev/null
+++ b/build_system/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "y"
+version = "0.1.0"
diff --git a/build_system/Cargo.toml b/build_system/Cargo.toml
new file mode 100644
index 00000000000..f47b9bc5540
--- /dev/null
+++ b/build_system/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "y"
+version = "0.1.0"
+edition = "2021"
+
+[[bin]]
+name = "y"
+path = "main.rs"
+
+[features]
+unstable-features = [] # for rust-analyzer
+
+# Do not add any dependencies
diff --git a/build_system/build_sysroot.rs b/build_system/build_sysroot.rs
index dab9c77d1a4..2ed6272b2c5 100644
--- a/build_system/build_sysroot.rs
+++ b/build_system/build_sysroot.rs
@@ -225,7 +225,7 @@ fn build_clif_sysroot_for_triple(
     match fs::read_to_string(SYSROOT_RUSTC_VERSION.to_path(dirs)) {
         Err(e) => {
             eprintln!("Failed to get rustc version for patched sysroot source: {}", e);
-            eprintln!("Hint: Try `./y.rs prepare` to patch the sysroot source");
+            eprintln!("Hint: Try `./y.sh prepare` to patch the sysroot source");
             process::exit(1);
         }
         Ok(source_version) => {
@@ -234,7 +234,7 @@ fn build_clif_sysroot_for_triple(
                 eprintln!("The patched sysroot source is outdated");
                 eprintln!("Source version: {}", source_version.trim());
                 eprintln!("Rustc version:  {}", rustc_version.trim());
-                eprintln!("Hint: Try `./y.rs prepare` to update the patched sysroot source");
+                eprintln!("Hint: Try `./y.sh prepare` to update the patched sysroot source");
                 process::exit(1);
             }
         }
diff --git a/build_system/mod.rs b/build_system/main.rs
similarity index 98%
rename from build_system/mod.rs
rename to build_system/main.rs
index e1b46c3120e..06395eb141c 100644
--- a/build_system/mod.rs
+++ b/build_system/main.rs
@@ -1,3 +1,7 @@
+#![warn(rust_2018_idioms)]
+#![warn(unused_lifetimes)]
+#![warn(unreachable_pub)]
+
 use std::env;
 use std::path::PathBuf;
 use std::process;
@@ -37,19 +41,19 @@ enum Command {
 }
 
 #[derive(Copy, Clone, Debug)]
-pub(crate) enum SysrootKind {
+enum SysrootKind {
     None,
     Clif,
     Llvm,
 }
 
 #[derive(Clone, Debug)]
-pub(crate) enum CodegenBackend {
+enum CodegenBackend {
     Local(PathBuf),
     Builtin(String),
 }
 
-pub(crate) fn main() {
+fn main() {
     if env::var("RUST_BACKTRACE").is_err() {
         env::set_var("RUST_BACKTRACE", "1");
     }
diff --git a/build_system/usage.txt b/build_system/usage.txt
index 98726ae5af1..9d20cdca6a7 100644
--- a/build_system/usage.txt
+++ b/build_system/usage.txt
@@ -1,11 +1,11 @@
 The build system of cg_clif.
 
 USAGE:
-    ./y.rs prepare [--out-dir DIR] [--download-dir DIR]
-    ./y.rs build [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
-    ./y.rs test [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
-    ./y.rs abi-cafe [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
-    ./y.rs bench [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
+    ./y.sh prepare [--out-dir DIR] [--download-dir DIR]
+    ./y.sh build [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
+    ./y.sh test [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
+    ./y.sh abi-cafe [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
+    ./y.sh bench [--debug] [--sysroot none|clif|llvm] [--out-dir DIR] [--download-dir DIR] [--no-unstable-features] [--frozen]
 
 OPTIONS:
     --debug
@@ -40,7 +40,7 @@ REQUIREMENTS:
     * Rustup: By default rustup is used to install the right nightly version. If you don't want to
       use rustup, you can manually install the nightly version indicated by rust-toolchain.toml and
       point the CARGO, RUSTC and RUSTDOC env vars to the right executables.
-    * Git: `./y.rs prepare` uses git for applying patches and on Windows for downloading test repos.
-    * Curl and tar (non-Windows only): Used by `./y.rs prepare` to download a single commit for
+    * Git: `./y.sh prepare` uses git for applying patches and on Windows for downloading test repos.
+    * Curl and tar (non-Windows only): Used by `./y.sh prepare` to download a single commit for
       repos. Git will be used to clone the whole repo when using Windows.
-    * [Hyperfine](https://github.com/sharkdp/hyperfine/): Used for benchmarking with `./y.rs bench`.
+    * [Hyperfine](https://github.com/sharkdp/hyperfine/): Used for benchmarking with `./y.sh bench`.
diff --git a/clean_all.sh b/clean_all.sh
index cdfc2e143e6..19405a53d1c 100755
--- a/clean_all.sh
+++ b/clean_all.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -e
 
-rm -rf target/ download/ build/ dist/ y.bin y.bin.dSYM y.exe y.pdb
+rm -rf target/ build_system/target download/ build/ dist/ y.bin y.bin.dSYM y.exe y.pdb
 
 # Kept for now in case someone updates their checkout of cg_clif before running clean_all.sh
 # FIXME remove at some point in the future
diff --git a/docs/usage.md b/docs/usage.md
index 4c2b0fa1704..c6210f958d6 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -2,7 +2,7 @@
 
 rustc_codegen_cranelift can be used as a near-drop-in replacement for `cargo build` or `cargo run` for existing projects.
 
-Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`y.rs prepare` and `y.rs build` or `test.sh`).
+Assuming `$cg_clif_dir` is the directory you cloned this repo into and you followed the instructions (`y.sh prepare` and `y.sh build` or `test.sh`).
 
 ## Cargo
 
diff --git a/scripts/rustup.sh b/scripts/rustup.sh
index 3cbeb6375de..6b446aafb7b 100755
--- a/scripts/rustup.sh
+++ b/scripts/rustup.sh
@@ -32,7 +32,7 @@ case $1 in
 
         ./clean_all.sh
 
-        ./y.rs prepare
+        ./y.sh prepare
 
         (cd download/sysroot && cargo update && cargo fetch && cp Cargo.lock ../../build_sysroot/)
         ;;
diff --git a/scripts/setup_rust_fork.sh b/scripts/setup_rust_fork.sh
index abb09775d21..15b16b42be5 100644
--- a/scripts/setup_rust_fork.sh
+++ b/scripts/setup_rust_fork.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -e
 
-./y.rs build --no-unstable-features
+./y.sh build --no-unstable-features
 
 echo "[SETUP] Rust fork"
 git clone https://github.com/rust-lang/rust.git || true
diff --git a/test.sh b/test.sh
index 13e7784539d..6357eebf026 100755
--- a/test.sh
+++ b/test.sh
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec ./y.rs test "$@"
+exec ./y.sh test "$@"
diff --git a/y.rs b/y.rs
index a68a10500f5..e806a64d943 100755
--- a/y.rs
+++ b/y.rs
@@ -1,35 +1,6 @@
 #!/usr/bin/env bash
 #![deny(unsafe_code)] /*This line is ignored by bash
 # This block is ignored by rustc
-set -e
-echo "[BUILD] y.rs" 1>&2
-rustc $0 -o ${0/.rs/.bin} -Cdebuginfo=1 --edition 2021
-exec ${0/.rs/.bin} $@
+echo "Warning: y.rs is a deprecated alias for y.sh" 1>&2
+exec ./y.sh "$@"
 */
-
-#![warn(rust_2018_idioms)]
-#![warn(unused_lifetimes)]
-#![warn(unreachable_pub)]
-
-//! The build system for cg_clif
-//!
-//! # Manual compilation
-//!
-//! If your system doesn't support shell scripts you can manually compile and run this file using
-//! for example:
-//!
-//! ```shell
-//! $ rustc y.rs -o y.bin
-//! $ ./y.bin
-//! ```
-//!
-//! # Naming
-//!
-//! The name `y.rs` was chosen to not conflict with rustc's `x.py`.
-
-#[path = "build_system/mod.rs"]
-mod build_system;
-
-fn main() {
-    build_system::main();
-}
diff --git a/y.sh b/y.sh
new file mode 100755
index 00000000000..bc925a23e2a
--- /dev/null
+++ b/y.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+set -e
+echo "[BUILD] build system" 1>&2
+rustc build_system/main.rs -o y.bin -Cdebuginfo=1 --edition 2021
+exec ./y.bin "$@"