Use -Zcodegen-backend instead of a rustc replacement in cargo-clif

Author: bjorn3

build_system/build_backend.rs

@@ -34,18 +34,6 @@ pub(crate) fn build_backend(
         _ => unreachable!(),
     }
 
-    // Set the rpath to make the cg_clif executable find librustc_codegen_cranelift without changing
-    // LD_LIBRARY_PATH
-    if cfg!(unix) {
-        if cfg!(target_os = "macos") {
-            rustflags += " -Csplit-debuginfo=unpacked \
-                -Clink-arg=-Wl,-rpath,@loader_path/../lib \
-                -Zosx-rpath-install-name";
-        } else {
-            rustflags += " -Clink-arg=-Wl,-rpath=$ORIGIN/../lib ";
-        }
-    }
-
     cmd.env("RUSTFLAGS", rustflags);
 
     eprintln!("[BUILD] rustc_codegen_cranelift");

build_system/build_sysroot.rs

@@ -33,19 +33,16 @@ pub(crate) fn build_sysroot(
         .join(&cg_clif_dylib);
     try_hard_link(cg_clif_build_dir.join(cg_clif_dylib), &cg_clif_dylib_path);
 
-    try_hard_link(
-        cg_clif_build_dir.join(get_file_name("cg_clif", "bin")),
-        target_dir.join("bin").join(get_file_name("cg_clif", "bin")),
-    );
-
-    // Build and copy cargo wrapper
-    let mut build_cargo_wrapper_cmd = Command::new("rustc");
-    build_cargo_wrapper_cmd
-        .arg("scripts/cargo-clif.rs")
-        .arg("-o")
-        .arg(target_dir.join("cargo-clif"))
-        .arg("-g");
-    spawn_and_wait(build_cargo_wrapper_cmd);
+    // Build and copy rustc and cargo wrappers
+    for wrapper in ["rustc-clif", "cargo-clif"] {
+        let mut build_cargo_wrapper_cmd = Command::new("rustc");
+        build_cargo_wrapper_cmd
+            .arg(PathBuf::from("scripts").join(format!("{wrapper}.rs")))
+            .arg("-o")
+            .arg(target_dir.join(wrapper))
+            .arg("-g");
+        spawn_and_wait(build_cargo_wrapper_cmd);
+    }
 
     let default_sysroot = super::rustc_info::get_default_sysroot();
 

docs/usage.md

@@ -19,7 +19,7 @@ This will build your project with rustc_codegen_cranelift instead of the usual L
 > You should prefer using the Cargo method.
 
 ```bash
-$ $cg_clif_dir/build/bin/cg_clif my_crate.rs
+$ $cg_clif_dir/build/rustc-clif my_crate.rs
 ```
 
 ## Jit mode
@@ -38,7 +38,7 @@ $ $cg_clif_dir/build/cargo-clif jit
 or
 
 ```bash
-$ $cg_clif_dir/build/bin/cg_clif -Zunstable-features -Cllvm-args=mode=jit -Cprefer-dynamic my_crate.rs
+$ $cg_clif_dir/build/rustc-clif -Zunstable-features -Cllvm-args=mode=jit -Cprefer-dynamic my_crate.rs
 ```
 
 There is also an experimental lazy jit mode. In this mode functions are only compiled once they are
@@ -54,7 +54,7 @@ These are a few functions that allow you to easily run rust code from the shell
 
 ```bash
 function jit_naked() {
-    echo "$@" | $cg_clif_dir/build/bin/cg_clif - -Zunstable-features -Cllvm-args=mode=jit -Cprefer-dynamic
+    echo "$@" | $cg_clif_dir/build/rustc-clif - -Zunstable-features -Cllvm-args=mode=jit -Cprefer-dynamic
 }
 
 function jit() {

scripts/cargo-clif.rs

@@ -5,20 +5,11 @@ use std::path::PathBuf;
 use std::process::Command;
 
 fn main() {
-    if env::var("RUSTC_WRAPPER").map_or(false, |wrapper| wrapper.contains("sccache")) {
-        eprintln!(
-            "\x1b[1;93m=== Warning: Unsetting RUSTC_WRAPPER to prevent interference with sccache ===\x1b[0m"
-        );
-        env::remove_var("RUSTC_WRAPPER");
-    }
-
     let sysroot = PathBuf::from(env::current_exe().unwrap().parent().unwrap());
 
-    env::set_var("RUSTC", sysroot.join("bin/cg_clif".to_string() + env::consts::EXE_SUFFIX));
-
-    let mut rustdoc_flags = env::var("RUSTDOCFLAGS").unwrap_or(String::new());
-    rustdoc_flags.push_str(" -Cpanic=abort -Zpanic-abort-tests -Zcodegen-backend=");
-    rustdoc_flags.push_str(
+    let mut rustflags = String::new();
+    rustflags.push_str(" -Cpanic=abort -Zpanic-abort-tests -Zcodegen-backend=");
+    rustflags.push_str(
         sysroot
             .join(if cfg!(windows) { "bin" } else { "lib" })
             .join(
@@ -29,9 +20,10 @@ fn main() {
             .to_str()
             .unwrap(),
     );
-    rustdoc_flags.push_str(" --sysroot ");
-    rustdoc_flags.push_str(sysroot.to_str().unwrap());
-    env::set_var("RUSTDOCFLAGS", rustdoc_flags);
+    rustflags.push_str(" --sysroot ");
+    rustflags.push_str(sysroot.to_str().unwrap());
+    env::set_var("RUSTFLAGS", env::var("RUSTFLAGS").unwrap_or(String::new()) + &rustflags);
+    env::set_var("RUSTDOCFLAGS", env::var("RUSTDOCFLAGS").unwrap_or(String::new()) + &rustflags);
 
     // Ensure that the right toolchain is used
     env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));

scripts/config.sh

@@ -2,8 +2,7 @@
 #![forbid(unsafe_code)]/* This line is ignored by bash
 # This block is ignored by rustc
 pushd $(dirname "$0")/../
-source scripts/config.sh
-RUSTC="$(pwd)/build/bin/cg_clif"
+RUSTC="$(pwd)/build/rustc-clif"
 popd
 PROFILE=$1 OUTPUT=$2 exec $RUSTC -Zunstable-options -Cllvm-args=mode=jit -Cprefer-dynamic $0
 #*/

scripts/filter_profile.rs

@@ -0,0 +1,36 @@
+use std::env;
+use std::ffi::OsString;
+#[cfg(unix)]
+use std::os::unix::process::CommandExt;
+use std::path::PathBuf;
+use std::process::Command;
+
+fn main() {
+    let sysroot = PathBuf::from(env::current_exe().unwrap().parent().unwrap());
+
+    let cg_clif_dylib_path = sysroot.join(if cfg!(windows) { "bin" } else { "lib" }).join(
+        env::consts::DLL_PREFIX.to_string() + "rustc_codegen_cranelift" + env::consts::DLL_SUFFIX,
+    );
+
+    let mut args = std::env::args_os().skip(1).collect::<Vec<_>>();
+    args.push(OsString::from("-Cpanic=abort"));
+    args.push(OsString::from("-Zpanic-abort-tests"));
+    let mut codegen_backend_arg = OsString::from("-Zcodegen-backend=");
+    codegen_backend_arg.push(cg_clif_dylib_path);
+    args.push(codegen_backend_arg);
+    if !args.contains(&OsString::from("--sysroot")) {
+        args.push(OsString::from("--sysroot"));
+        args.push(OsString::from(sysroot.to_str().unwrap()));
+    }
+
+    // Ensure that the right toolchain is used
+    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+
+    #[cfg(unix)]
+    Command::new("rustc").args(args).exec();
+
+    #[cfg(not(unix))]
+    std::process::exit(
+        Command::new("rustc").args(args).spawn().unwrap().wait().unwrap().code().unwrap_or(1),
+    );
+}

scripts/rustc-clif.rs

@@ -2,7 +2,6 @@
 set -e
 
 ./y.rs build --no-unstable-features
-source scripts/config.sh
 
 echo "[SETUP] Rust fork"
 git clone https://github.com/rust-lang/rust.git || true
@@ -52,7 +51,7 @@ changelog-seen = 2
 ninja = false
 
 [build]
-rustc = "$(pwd)/../build/bin/cg_clif"
+rustc = "$(pwd)/../build/rustc-clif"
 cargo = "$(rustup which cargo)"
 full-bootstrap = true
 local-rebuild = true

scripts/setup_rust_fork.sh

@@ -2,8 +2,6 @@
 
 set -e
 
-source scripts/config.sh
-
 export CG_CLIF_DISPLAY_CG_TIME=1
 export CG_CLIF_DISABLE_INCR_CACHE=1
 
@@ -31,8 +29,7 @@ if [[ "$(uname)" == 'Darwin' ]]; then
    export RUSTFLAGS="$RUSTFLAGS -Clink-arg=-undefined -Clink-arg=dynamic_lookup"
 fi
 
-export RUSTC=false # ensure that cg_llvm isn't accidentally used
-MY_RUSTC="$(pwd)/build/bin/cg_clif $RUSTFLAGS -L crate=target/out --out-dir target/out -Cdebuginfo=2"
+MY_RUSTC="$(pwd)/build/rustc-clif $RUSTFLAGS -L crate=target/out --out-dir target/out -Cdebuginfo=2"
 
 function no_sysroot_tests() {
     echo "[BUILD] mini_core"
@@ -124,7 +121,7 @@ function extended_sysroot_tests() {
     if [[ "$HOST_TRIPLE" = "$TARGET_TRIPLE" ]]; then
         echo "[BENCH COMPILE] ebobby/simple-raytracer"
         hyperfine --runs "${RUN_RUNS:-10}" --warmup 1 --prepare "../build/cargo-clif clean" \
-        "RUSTC=rustc RUSTFLAGS='' cargo build" \
+        "RUSTFLAGS='' cargo build" \
         "../build/cargo-clif build"
 
         echo "[BENCH RUN] ebobby/simple-raytracer"