check lld version to choose correct flag for tests

diff --git a/src/bootstrap/bin/rustdoc.rs b/src/bootstrap/bin/rustdoc.rs
index e69cab956c5078eed10822aefc6cf5b0489c718d..23828f4758d67db275cce6d942ecb6da11d962e9 100644 (file)
--- a/src/bootstrap/bin/rustdoc.rs
+++ b/src/bootstrap/bin/rustdoc.rs
@@ -55,13 +55,9 @@ fn main() {
         arg.push(&linker);
         cmd.arg(arg);
     }
-    if env::var_os("RUSTDOC_FUSE_LD_LLD").is_some() {
+    if let Ok(no_threads) = env::var("RUSTDOC_LLD_NO_THREADS") {
         cmd.arg("-Clink-arg=-fuse-ld=lld");
-        if cfg!(windows) {
-            cmd.arg("-Clink-arg=-Wl,/threads:1");
-        } else {
-            cmd.arg("-Clink-arg=-Wl,--threads=1");
-        }
+        cmd.arg(format!("-Clink-arg=-Wl,{}", no_threads));
     }
     // Cargo doesn't pass RUSTDOCFLAGS to proc_macros:
     // https://github.com/rust-lang/cargo/issues/4423

diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 7e70e99bb8ca22ee78d1d78170cd2736e736bab4..f5def8ba8341f58b817afaedb9828e75a6ad0ff7 100644 (file)
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -1152,8 +1152,8 @@ fn lld_flags(&self, target: TargetSelection) -> impl Iterator<Item = String> {
                 options[0] = Some("-Clink-arg=-fuse-ld=lld".to_string());
             }
 
-            let threads = if target.contains("windows") { "/threads:1" } else { "--threads=1" };
-            options[1] = Some(format!("-Clink-arg=-Wl,{}", threads));
+            let no_threads = util::lld_flag_no_threads(target.contains("windows"));
+            options[1] = Some(format!("-Clink-arg=-Wl,{}", no_threads));
         }
 
         IntoIterator::into_iter(options).flatten()

diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 8d4914097787f920ed1c295c9028f3a81e017cf7..f336f0496a14da5490a0c0e1af11e1c6cdc134d6 100644 (file)
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -727,7 +727,10 @@ fn run(self, builder: &Builder<'_>) {
             cmd.env("RUSTDOC_LINKER", linker);
         }
         if builder.is_fuse_ld_lld(self.compiler.host) {
-            cmd.env("RUSTDOC_FUSE_LD_LLD", "1");
+            cmd.env(
+                "RUSTDOC_LLD_NO_THREADS",
+                util::lld_flag_no_threads(self.compiler.host.contains("windows")),
+            );
         }
         try_run(builder, &mut cmd);
     }

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 }
+}