Auto merge of #103846 - Kobzol:revert-103295-ninja, r=cuviper

[rust.git] / src / bootstrap / util.rs

diff --git a/src/bootstrap/util.rs b/src/bootstrap/util.rs
index 0ebabbd5ca5c04599f065a52f7654a93e6232fcc..20c3801f0a50222cbcc792f98a2786a993d7b5c6 100644 (file)
--- a/src/bootstrap/util.rs
+++ b/src/bootstrap/util.rs
@@ -13,6 +13,7 @@
 
 use crate::builder::Builder;
 use crate::config::{Config, TargetSelection};
+use crate::OnceCell;
 
 /// A helper macro to `unwrap` a result except also print out details like:
 ///
@@ -607,3 +608,16 @@ pub fn get_clang_cl_resource_dir(clang_cl_path: &str) -> PathBuf {
     let clang_rt_dir = clang_rt_builtins.parent().expect("The clang lib folder should exist");
     clang_rt_dir.to_path_buf()
 }
+
+pub fn lld_flag_no_threads(is_windows: bool) -> &'static str {
+    static LLD_NO_THREADS: OnceCell<(&'static str, &'static str)> = OnceCell::new();
+    let (windows, other) = LLD_NO_THREADS.get_or_init(|| {
+        let out = output(Command::new("lld").arg("-flavor").arg("ld").arg("--version"));
+        let newer = match (out.find(char::is_numeric), out.find('.')) {
+            (Some(b), Some(e)) => out.as_str()[b..e].parse::<i32>().ok().unwrap_or(14) > 10,
+            _ => true,
+        };
+        if newer { ("/threads:1", "--threads=1") } else { ("/no-threads", "--no-threads") }
+    });
+    if is_windows { windows } else { other }
+}