Merge commit '11a0cceab966e5ff1058ddbcab5977e8a1d6d290' into subtree-update_cg_gcc_2023-10-09

1 files changed, 125 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_gcc/build_system/src/config.rs b/compiler/rustc_codegen_gcc/build_system/src/config.rs
new file mode 100644
index 00000000000..4f2e33f0f99
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/build_system/src/config.rs
@@ -0,0 +1,125 @@
+use crate::utils::{get_gcc_path, get_os_name, get_rustc_host_triple};
+use std::collections::HashMap;
+use std::env as std_env;
+
+pub struct ConfigInfo {
+    pub target_triple: String,
+    pub rustc_command: Vec<String>,
+    pub run_wrapper: Option<&'static str>,
+}
+
+// Returns the beginning for the command line of rustc.
+pub fn set_config(
+    env: &mut HashMap<String, String>,
+    test_flags: &[String],
+    gcc_path: Option<&str>,
+) -> Result<ConfigInfo, String> {
+    env.insert("CARGO_INCREMENTAL".to_string(), "0".to_string());
+
+    let gcc_path = match gcc_path {
+        Some(path) => path.to_string(),
+        None => get_gcc_path()?,
+    };
+    env.insert("GCC_PATH".to_string(), gcc_path.clone());
+
+    let os_name = get_os_name()?;
+    let dylib_ext = match os_name.as_str() {
+        "Linux" => "so",
+        "Darwin" => "dylib",
+        os => return Err(format!("unsupported OS `{}`", os)),
+    };
+    let host_triple = get_rustc_host_triple()?;
+    let mut linker = None;
+    let mut target_triple = host_triple.as_str();
+    let mut run_wrapper = None;
+    // FIXME: handle this with a command line flag?
+    // let mut target_triple = "m68k-unknown-linux-gnu";
+
+    if host_triple != target_triple {
+        if target_triple == "m68k-unknown-linux-gnu" {
+            target_triple = "mips-unknown-linux-gnu";
+            linker = Some("-Clinker=m68k-linux-gcc");
+        } else if target_triple == "aarch64-unknown-linux-gnu" {
+            // We are cross-compiling for aarch64. Use the correct linker and run tests in qemu.
+            linker = Some("-Clinker=aarch64-linux-gnu-gcc");
+            run_wrapper = Some("qemu-aarch64 -L /usr/aarch64-linux-gnu");
+        } else {
+            return Err(format!("unknown non-native platform `{}`", target_triple));
+        }
+    }
+    let current_dir =
+        std_env::current_dir().map_err(|error| format!("`current_dir` failed: {:?}", error))?;
+    let channel = if let Some(channel) = env.get("CHANNEL") {
+        channel.as_str()
+    } else {
+        "debug"
+    };
+    let cg_backend_path = current_dir
+        .join("target")
+        .join(channel)
+        .join(&format!("librustc_codegen_gcc.{}", dylib_ext));
+    let sysroot_path = current_dir.join("build_sysroot/sysroot");
+    let mut rustflags = Vec::new();
+    if let Some(cg_rustflags) = env.get("CG_RUSTFLAGS") {
+        rustflags.push(cg_rustflags.clone());
+    }
+    if let Some(linker) = linker {
+        rustflags.push(linker.to_string());
+    }
+    rustflags.extend_from_slice(&[
+        "-Csymbol-mangling-version=v0".to_string(),
+        "-Cdebuginfo=2".to_string(),
+        format!("-Zcodegen-backend={}", cg_backend_path.display()),
+        "--sysroot".to_string(),
+        sysroot_path.display().to_string(),
+    ]);
+
+    // Since we don't support ThinLTO, disable LTO completely when not trying to do LTO.
+    // TODO(antoyo): remove when we can handle ThinLTO.
+    if !env.contains_key(&"FAT_LTO".to_string()) {
+        rustflags.push("-Clto=off".to_string());
+    }
+    rustflags.extend_from_slice(test_flags);
+    // FIXME(antoyo): remove once the atomic shim is gone
+    if os_name == "Darwin" {
+        rustflags.extend_from_slice(&[
+            "-Clink-arg=-undefined".to_string(),
+            "-Clink-arg=dynamic_lookup".to_string(),
+        ]);
+    }
+    env.insert("RUSTFLAGS".to_string(), rustflags.join(" "));
+    // display metadata load errors
+    env.insert("RUSTC_LOG".to_string(), "warn".to_string());
+
+    let sysroot = current_dir.join(&format!(
+        "build_sysroot/sysroot/lib/rustlib/{}/lib",
+        target_triple
+    ));
+    let ld_library_path = format!(
+        "{target}:{sysroot}:{gcc_path}",
+        target = current_dir.join("target/out").display(),
+        sysroot = sysroot.display(),
+    );
+    env.insert("LD_LIBRARY_PATH".to_string(), ld_library_path.clone());
+    env.insert("DYLD_LIBRARY_PATH".to_string(), ld_library_path);
+
+    // NOTE: To avoid the -fno-inline errors, use /opt/gcc/bin/gcc instead of cc.
+    // To do so, add a symlink for cc to /opt/gcc/bin/gcc in our PATH.
+    // Another option would be to add the following Rust flag: -Clinker=/opt/gcc/bin/gcc
+    let path = std::env::var("PATH").unwrap_or_default();
+    env.insert("PATH".to_string(), format!("/opt/gcc/bin:{}", path));
+
+    let mut rustc_command = vec!["rustc".to_string()];
+    rustc_command.extend_from_slice(&rustflags);
+    rustc_command.extend_from_slice(&[
+        "-L".to_string(),
+        "crate=target/out".to_string(),
+        "--out-dir".to_string(),
+        "target/out".to_string(),
+    ]);
+    Ok(ConfigInfo {
+        target_triple: target_triple.to_string(),
+        rustc_command,
+        run_wrapper,
+    })
+}