Remove the entry point triggering -Zjobserver-per-rustc

src/cargo/core/compiler/context/mod.rs

@@ -71,11 +71,6 @@ pub struct Context<'a, 'cfg> {
     /// metadata files in addition to the rlib itself.
     rmeta_required: HashSet<Unit>,
 
-    /// When we're in jobserver-per-rustc process mode, this keeps those
-    /// jobserver clients for each Unit (which eventually becomes a rustc
-    /// process).
-    pub rustc_clients: HashMap<Unit, Client>,
-
     /// Map of the LTO-status of each unit. This indicates what sort of
     /// compilation is happening (only object, only bitcode, both, etc), and is
     /// precalculated early on.
@@ -124,7 +119,6 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
             primary_packages: HashSet::new(),
             files: None,
             rmeta_required: HashSet::new(),
-            rustc_clients: HashMap::new(),
             lto: HashMap::new(),
             metadata_for_doc_units: HashMap::new(),
             failed_scrape_units: Arc::new(Mutex::new(HashSet::new())),
@@ -614,24 +608,6 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
         self.rmeta_required.contains(unit)
     }
 
-    /// Used by `-Zjobserver-per-rustc`.
-    pub fn new_jobserver(&mut self) -> CargoResult<Client> {
-        let tokens = self.bcx.jobs() as usize;
-        let client = Client::new(tokens).with_context(|| "failed to create jobserver")?;
-
-        // Drain the client fully
-        for i in 0..tokens {
-            client.acquire_raw().with_context(|| {
-                format!(
-                    "failed to fully drain {}/{} token from jobserver at startup",
-                    i, tokens,
-                )
-            })?;
-        }
-
-        Ok(client)
-    }
-
     /// Finds metadata for Doc/Docscrape units.
     ///
     /// rustdoc needs a -Cmetadata flag in order to recognize StableCrateIds that refer to

src/cargo/core/compiler/mod.rs

@@ -715,14 +715,7 @@ fn prepare_rustc(
         base.env("CARGO_TARGET_TMPDIR", tmp.display().to_string());
     }
 
-    if cx.bcx.config.cli_unstable().jobserver_per_rustc {
-        let client = cx.new_jobserver()?;
-        base.inherit_jobserver(&client);
-        base.arg("-Z").arg("jobserver-token-requests");
-        assert!(cx.rustc_clients.insert(unit.clone(), client).is_none());
-    } else {
-        base.inherit_jobserver(&cx.jobserver);
-    }
+    base.inherit_jobserver(&cx.jobserver);
     build_base_args(cx, &mut base, unit, crate_types)?;
     build_deps_args(&mut base, cx, unit)?;
     Ok(base)

src/cargo/core/features.rs

@@ -716,7 +716,6 @@ unstable_cli_options!(
     doctest_xcompile: bool = ("Compile and run doctests for non-host target using runner config"),
     dual_proc_macros: bool = ("Build proc-macros for both the host and the target"),
     features: Option<Vec<String>>  = (HIDDEN),
-    jobserver_per_rustc: bool = (HIDDEN),
     minimal_versions: bool = ("Resolve minimal dependency versions instead of maximum"),
     mtime_on_use: bool = ("Configure Cargo to update the mtime of used files"),
     no_index_update: bool = ("Do not update the registry index even if the cache is outdated"),
@@ -966,7 +965,6 @@ impl CliUnstable {
             "doctest-xcompile" => self.doctest_xcompile = parse_empty(k, v)?,
             "doctest-in-workspace" => self.doctest_in_workspace = parse_empty(k, v)?,
             "panic-abort-tests" => self.panic_abort_tests = parse_empty(k, v)?,
-            "jobserver-per-rustc" => self.jobserver_per_rustc = parse_empty(k, v)?,
             "host-config" => self.host_config = parse_empty(k, v)?,
             "target-applies-to-host" => self.target_applies_to_host = parse_empty(k, v)?,
             "publish-timeout" => self.publish_timeout = parse_empty(k, v)?,