Merge commit '35d9c6bf25' into sync_cg_clif-2022-02-23

compiler/rustc_codegen_cranelift/build_system/mod.rs

@@ -0,0 +1,127 @@
+use std::env;
+use std::path::PathBuf;
+use std::process;
+
+mod build_backend;
+mod build_sysroot;
+mod config;
+mod prepare;
+mod rustc_info;
+mod utils;
+
+fn usage() {
+    eprintln!("Usage:");
+    eprintln!("  ./y.rs prepare");
+    eprintln!(
+        "  ./y.rs build [--debug] [--sysroot none|clif|llvm] [--target-dir DIR] [--no-unstable-features]"
+    );
+}
+
+macro_rules! arg_error {
+    ($($err:tt)*) => {{
+        eprintln!($($err)*);
+        usage();
+        std::process::exit(1);
+    }};
+}
+
+enum Command {
+    Build,
+}
+
+#[derive(Copy, Clone)]
+pub(crate) enum SysrootKind {
+    None,
+    Clif,
+    Llvm,
+}
+
+pub fn main() {
+    env::set_var("CG_CLIF_DISPLAY_CG_TIME", "1");
+    env::set_var("CG_CLIF_DISABLE_INCR_CACHE", "1");
+    // The target dir is expected in the default location. Guard against the user changing it.
+    env::set_var("CARGO_TARGET_DIR", "target");
+
+    let mut args = env::args().skip(1);
+    let command = match args.next().as_deref() {
+        Some("prepare") => {
+            if args.next().is_some() {
+                arg_error!("./x.rs prepare doesn't expect arguments");
+            }
+            prepare::prepare();
+            process::exit(0);
+        }
+        Some("build") => Command::Build,
+        Some(flag) if flag.starts_with('-') => arg_error!("Expected command found flag {}", flag),
+        Some(command) => arg_error!("Unknown command {}", command),
+        None => {
+            usage();
+            process::exit(0);
+        }
+    };
+
+    let mut target_dir = PathBuf::from("build");
+    let mut channel = "release";
+    let mut sysroot_kind = SysrootKind::Clif;
+    let mut use_unstable_features = true;
+    while let Some(arg) = args.next().as_deref() {
+        match arg {
+            "--target-dir" => {
+                target_dir = PathBuf::from(args.next().unwrap_or_else(|| {
+                    arg_error!("--target-dir requires argument");
+                }))
+            }
+            "--debug" => channel = "debug",
+            "--sysroot" => {
+                sysroot_kind = match args.next().as_deref() {
+                    Some("none") => SysrootKind::None,
+                    Some("clif") => SysrootKind::Clif,
+                    Some("llvm") => SysrootKind::Llvm,
+                    Some(arg) => arg_error!("Unknown sysroot kind {}", arg),
+                    None => arg_error!("--sysroot requires argument"),
+                }
+            }
+            "--no-unstable-features" => use_unstable_features = false,
+            flag if flag.starts_with("-") => arg_error!("Unknown flag {}", flag),
+            arg => arg_error!("Unexpected argument {}", arg),
+        }
+    }
+
+    let host_triple = if let Ok(host_triple) = std::env::var("HOST_TRIPLE") {
+        host_triple
+    } else if let Some(host_triple) = config::get_value("host") {
+        host_triple
+    } else {
+        rustc_info::get_host_triple()
+    };
+    let target_triple = if let Ok(target_triple) = std::env::var("TARGET_TRIPLE") {
+        if target_triple != "" {
+            target_triple
+        } else {
+            host_triple.clone() // Empty target triple can happen on GHA
+        }
+    } else if let Some(target_triple) = config::get_value("target") {
+        target_triple
+    } else {
+        host_triple.clone()
+    };
+
+    if target_triple.ends_with("-msvc") {
+        eprintln!("The MSVC toolchain is not yet supported by rustc_codegen_cranelift.");
+        eprintln!("Switch to the MinGW toolchain for Windows support.");
+        eprintln!("Hint: You can use `rustup set default-host x86_64-pc-windows-gnu` to");
+        eprintln!("set the global default target to MinGW");
+        process::exit(1);
+    }
+
+    let cg_clif_build_dir =
+        build_backend::build_backend(channel, &host_triple, use_unstable_features);
+    build_sysroot::build_sysroot(
+        channel,
+        sysroot_kind,
+        &target_dir,
+        cg_clif_build_dir,
+        &host_triple,
+        &target_triple,
+    );
+}